1 /*
2 * Copyright (c) 2008, 2017, 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.misc.JavaLangInvokeAccess;
29 import jdk.internal.misc.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.Stable;
37 import sun.invoke.empty.Empty;
38 import sun.invoke.util.ValueConversions;
39 import sun.invoke.util.VerifyType;
40 import sun.invoke.util.Wrapper;
41
42 import java.lang.reflect.Array;
43 import java.util.Arrays;
44 import java.util.Collections;
45 import java.util.Iterator;
46 import java.util.List;
47 import java.util.Map;
48 import java.util.function.Function;
49 import java.util.stream.Stream;
50
51 import static java.lang.invoke.LambdaForm.*;
52 import static java.lang.invoke.MethodHandleStatics.*;
53 import static java.lang.invoke.MethodHandles.Lookup.IMPL_LOOKUP;
54 import static jdk.internal.org.objectweb.asm.Opcodes.*;
55
56 /**
57 * Trusted implementation code for MethodHandle.
58 * @author jrose
59 */
60 /*non-public*/ abstract class MethodHandleImpl {
61
62 /// Factory methods to create method handles:
63
64 static MethodHandle makeArrayElementAccessor(Class<?> arrayClass, ArrayAccess access) {
65 if (arrayClass == Object[].class) {
66 return ArrayAccess.objectAccessor(access);
67 }
68 if (!arrayClass.isArray())
69 throw newIllegalArgumentException("not an array: "+arrayClass);
70 MethodHandle[] cache = ArrayAccessor.TYPED_ACCESSORS.get(arrayClass);
71 int cacheIndex = ArrayAccess.cacheIndex(access);
72 MethodHandle mh = cache[cacheIndex];
73 if (mh != null) return mh;
74 mh = ArrayAccessor.getAccessor(arrayClass, access);
75 MethodType correctType = ArrayAccessor.correctType(arrayClass, access);
76 if (mh.type() != correctType) {
77 assert(mh.type().parameterType(0) == Object[].class);
78 /* if access == SET */ assert(access != ArrayAccess.SET || mh.type().parameterType(2) == Object.class);
79 /* if access == GET */ assert(access != ArrayAccess.GET ||
80 (mh.type().returnType() == Object.class &&
81 correctType.parameterType(0).getComponentType() == correctType.returnType()));
82 // safe to view non-strictly, because element type follows from array type
83 mh = mh.viewAsType(correctType, false);
84 }
85 mh = makeIntrinsic(mh, ArrayAccess.intrinsic(access));
86 // Atomically update accessor cache.
87 synchronized(cache) {
88 if (cache[cacheIndex] == null) {
89 cache[cacheIndex] = mh;
90 } else {
91 // Throw away newly constructed accessor and use cached version.
92 mh = cache[cacheIndex];
93 }
94 }
95 return mh;
96 }
97
98 enum ArrayAccess {
99 GET, SET, LENGTH;
100
101 // As ArrayAccess and ArrayAccessor have a circular dependency, the ArrayAccess properties cannot be stored in
102 // final fields.
103
104 static String opName(ArrayAccess a) {
105 switch (a) {
106 case GET: return "getElement";
107 case SET: return "setElement";
108 case LENGTH: return "length";
109 }
110 throw unmatchedArrayAccess(a);
111 }
112
113 static MethodHandle objectAccessor(ArrayAccess a) {
114 switch (a) {
115 case GET: return ArrayAccessor.OBJECT_ARRAY_GETTER;
116 case SET: return ArrayAccessor.OBJECT_ARRAY_SETTER;
117 case LENGTH: return ArrayAccessor.OBJECT_ARRAY_LENGTH;
118 }
119 throw unmatchedArrayAccess(a);
120 }
121
122 static int cacheIndex(ArrayAccess a) {
123 switch (a) {
124 case GET: return ArrayAccessor.GETTER_INDEX;
125 case SET: return ArrayAccessor.SETTER_INDEX;
126 case LENGTH: return ArrayAccessor.LENGTH_INDEX;
127 }
128 throw unmatchedArrayAccess(a);
129 }
130
131 static Intrinsic intrinsic(ArrayAccess a) {
132 switch (a) {
133 case GET: return Intrinsic.ARRAY_LOAD;
134 case SET: return Intrinsic.ARRAY_STORE;
135 case LENGTH: return Intrinsic.ARRAY_LENGTH;
136 }
137 throw unmatchedArrayAccess(a);
138 }
139 }
140
141 static InternalError unmatchedArrayAccess(ArrayAccess a) {
142 return newInternalError("should not reach here (unmatched ArrayAccess: " + a + ")");
143 }
144
145 static final class ArrayAccessor {
146 /// Support for array element and length access
147 static final int GETTER_INDEX = 0, SETTER_INDEX = 1, LENGTH_INDEX = 2, INDEX_LIMIT = 3;
148 static final ClassValue<MethodHandle[]> TYPED_ACCESSORS
149 = new ClassValue<MethodHandle[]>() {
150 @Override
151 protected MethodHandle[] computeValue(Class<?> type) {
152 return new MethodHandle[INDEX_LIMIT];
153 }
154 };
155 static final MethodHandle OBJECT_ARRAY_GETTER, OBJECT_ARRAY_SETTER, OBJECT_ARRAY_LENGTH;
156 static {
157 MethodHandle[] cache = TYPED_ACCESSORS.get(Object[].class);
158 cache[GETTER_INDEX] = OBJECT_ARRAY_GETTER = makeIntrinsic(getAccessor(Object[].class, ArrayAccess.GET), Intrinsic.ARRAY_LOAD);
159 cache[SETTER_INDEX] = OBJECT_ARRAY_SETTER = makeIntrinsic(getAccessor(Object[].class, ArrayAccess.SET), Intrinsic.ARRAY_STORE);
160 cache[LENGTH_INDEX] = OBJECT_ARRAY_LENGTH = makeIntrinsic(getAccessor(Object[].class, ArrayAccess.LENGTH), Intrinsic.ARRAY_LENGTH);
161
162 assert(InvokerBytecodeGenerator.isStaticallyInvocable(ArrayAccessor.OBJECT_ARRAY_GETTER.internalMemberName()));
163 assert(InvokerBytecodeGenerator.isStaticallyInvocable(ArrayAccessor.OBJECT_ARRAY_SETTER.internalMemberName()));
164 assert(InvokerBytecodeGenerator.isStaticallyInvocable(ArrayAccessor.OBJECT_ARRAY_LENGTH.internalMemberName()));
165 }
166
167 static int getElementI(int[] a, int i) { return a[i]; }
168 static long getElementJ(long[] a, int i) { return a[i]; }
169 static float getElementF(float[] a, int i) { return a[i]; }
170 static double getElementD(double[] a, int i) { return a[i]; }
171 static boolean getElementZ(boolean[] a, int i) { return a[i]; }
172 static byte getElementB(byte[] a, int i) { return a[i]; }
173 static short getElementS(short[] a, int i) { return a[i]; }
174 static char getElementC(char[] a, int i) { return a[i]; }
175 static Object getElementL(Object[] a, int i) { return a[i]; }
176
177 static void setElementI(int[] a, int i, int x) { a[i] = x; }
178 static void setElementJ(long[] a, int i, long x) { a[i] = x; }
179 static void setElementF(float[] a, int i, float x) { a[i] = x; }
180 static void setElementD(double[] a, int i, double x) { a[i] = x; }
181 static void setElementZ(boolean[] a, int i, boolean x) { a[i] = x; }
182 static void setElementB(byte[] a, int i, byte x) { a[i] = x; }
183 static void setElementS(short[] a, int i, short x) { a[i] = x; }
184 static void setElementC(char[] a, int i, char x) { a[i] = x; }
185 static void setElementL(Object[] a, int i, Object x) { a[i] = x; }
186
187 static int lengthI(int[] a) { return a.length; }
188 static int lengthJ(long[] a) { return a.length; }
189 static int lengthF(float[] a) { return a.length; }
190 static int lengthD(double[] a) { return a.length; }
191 static int lengthZ(boolean[] a) { return a.length; }
192 static int lengthB(byte[] a) { return a.length; }
193 static int lengthS(short[] a) { return a.length; }
194 static int lengthC(char[] a) { return a.length; }
195 static int lengthL(Object[] a) { return a.length; }
196
197 static String name(Class<?> arrayClass, ArrayAccess access) {
198 Class<?> elemClass = arrayClass.getComponentType();
199 if (elemClass == null) throw newIllegalArgumentException("not an array", arrayClass);
200 return ArrayAccess.opName(access) + Wrapper.basicTypeChar(elemClass);
201 }
202 static MethodType type(Class<?> arrayClass, ArrayAccess access) {
203 Class<?> elemClass = arrayClass.getComponentType();
204 Class<?> arrayArgClass = arrayClass;
205 if (!elemClass.isPrimitive()) {
206 arrayArgClass = Object[].class;
207 elemClass = Object.class;
208 }
209 switch (access) {
210 case GET: return MethodType.methodType(elemClass, arrayArgClass, int.class);
211 case SET: return MethodType.methodType(void.class, arrayArgClass, int.class, elemClass);
212 case LENGTH: return MethodType.methodType(int.class, arrayArgClass);
213 }
214 throw unmatchedArrayAccess(access);
215 }
216 static MethodType correctType(Class<?> arrayClass, ArrayAccess access) {
217 Class<?> elemClass = arrayClass.getComponentType();
218 switch (access) {
219 case GET: return MethodType.methodType(elemClass, arrayClass, int.class);
220 case SET: return MethodType.methodType(void.class, arrayClass, int.class, elemClass);
221 case LENGTH: return MethodType.methodType(int.class, arrayClass);
222 }
223 throw unmatchedArrayAccess(access);
224 }
225 static MethodHandle getAccessor(Class<?> arrayClass, ArrayAccess access) {
226 String name = name(arrayClass, access);
227 MethodType type = type(arrayClass, access);
228 try {
229 return IMPL_LOOKUP.findStatic(ArrayAccessor.class, name, type);
230 } catch (ReflectiveOperationException ex) {
231 throw uncaughtException(ex);
232 }
233 }
234 }
235
236 /**
237 * Create a JVM-level adapter method handle to conform the given method
238 * handle to the similar newType, using only pairwise argument conversions.
239 * For each argument, convert incoming argument to the exact type needed.
240 * The argument conversions allowed are casting, boxing and unboxing,
241 * integral widening or narrowing, and floating point widening or narrowing.
242 * @param srcType required call type
243 * @param target original method handle
244 * @param strict if true, only asType conversions are allowed; if false, explicitCastArguments conversions allowed
245 * @param monobox if true, unboxing conversions are assumed to be exactly typed (Integer to int only, not long or double)
246 * @return an adapter to the original handle with the desired new type,
247 * or the original target if the types are already identical
248 * or null if the adaptation cannot be made
249 */
250 static MethodHandle makePairwiseConvert(MethodHandle target, MethodType srcType,
251 boolean strict, boolean monobox) {
252 MethodType dstType = target.type();
253 if (srcType == dstType)
254 return target;
255 return makePairwiseConvertByEditor(target, srcType, strict, monobox);
256 }
257
258 private static int countNonNull(Object[] array) {
259 int count = 0;
260 for (Object x : array) {
261 if (x != null) ++count;
262 }
263 return count;
264 }
265
266 static MethodHandle makePairwiseConvertByEditor(MethodHandle target, MethodType srcType,
267 boolean strict, boolean monobox) {
268 Object[] convSpecs = computeValueConversions(srcType, target.type(), strict, monobox);
269 int convCount = countNonNull(convSpecs);
270 if (convCount == 0)
271 return target.viewAsType(srcType, strict);
272 MethodType basicSrcType = srcType.basicType();
273 MethodType midType = target.type().basicType();
274 BoundMethodHandle mh = target.rebind();
275 // FIXME: Reduce number of bindings when there is more than one Class conversion.
276 // FIXME: Reduce number of bindings when there are repeated conversions.
277 for (int i = 0; i < convSpecs.length-1; i++) {
278 Object convSpec = convSpecs[i];
279 if (convSpec == null) continue;
280 MethodHandle fn;
281 if (convSpec instanceof Class) {
282 fn = getConstantHandle(MH_cast).bindTo(convSpec);
283 } else {
284 fn = (MethodHandle) convSpec;
285 }
286 Class<?> newType = basicSrcType.parameterType(i);
287 if (--convCount == 0)
288 midType = srcType;
289 else
290 midType = midType.changeParameterType(i, newType);
291 LambdaForm form2 = mh.editor().filterArgumentForm(1+i, BasicType.basicType(newType));
292 mh = mh.copyWithExtendL(midType, form2, fn);
293 mh = mh.rebind();
294 }
295 Object convSpec = convSpecs[convSpecs.length-1];
296 if (convSpec != null) {
297 MethodHandle fn;
298 if (convSpec instanceof Class) {
299 if (convSpec == void.class)
300 fn = null;
301 else
302 fn = getConstantHandle(MH_cast).bindTo(convSpec);
303 } else {
304 fn = (MethodHandle) convSpec;
305 }
306 Class<?> newType = basicSrcType.returnType();
307 assert(--convCount == 0);
308 midType = srcType;
309 if (fn != null) {
310 mh = mh.rebind(); // rebind if too complex
311 LambdaForm form2 = mh.editor().filterReturnForm(BasicType.basicType(newType), false);
312 mh = mh.copyWithExtendL(midType, form2, fn);
313 } else {
314 LambdaForm form2 = mh.editor().filterReturnForm(BasicType.basicType(newType), true);
315 mh = mh.copyWith(midType, form2);
316 }
317 }
318 assert(convCount == 0);
319 assert(mh.type().equals(srcType));
320 return mh;
321 }
322
323 static MethodHandle makePairwiseConvertIndirect(MethodHandle target, MethodType srcType,
324 boolean strict, boolean monobox) {
325 assert(target.type().parameterCount() == srcType.parameterCount());
326 // Calculate extra arguments (temporaries) required in the names array.
327 Object[] convSpecs = computeValueConversions(srcType, target.type(), strict, monobox);
328 final int INARG_COUNT = srcType.parameterCount();
329 int convCount = countNonNull(convSpecs);
330 boolean retConv = (convSpecs[INARG_COUNT] != null);
331 boolean retVoid = srcType.returnType() == void.class;
332 if (retConv && retVoid) {
333 convCount -= 1;
334 retConv = false;
335 }
336
337 final int IN_MH = 0;
338 final int INARG_BASE = 1;
339 final int INARG_LIMIT = INARG_BASE + INARG_COUNT;
340 final int NAME_LIMIT = INARG_LIMIT + convCount + 1;
341 final int RETURN_CONV = (!retConv ? -1 : NAME_LIMIT - 1);
342 final int OUT_CALL = (!retConv ? NAME_LIMIT : RETURN_CONV) - 1;
343 final int RESULT = (retVoid ? -1 : NAME_LIMIT - 1);
344
345 // Now build a LambdaForm.
346 MethodType lambdaType = srcType.basicType().invokerType();
347 Name[] names = arguments(NAME_LIMIT - INARG_LIMIT, lambdaType);
348
349 // Collect the arguments to the outgoing call, maybe with conversions:
350 final int OUTARG_BASE = 0; // target MH is Name.function, name Name.arguments[0]
351 Object[] outArgs = new Object[OUTARG_BASE + INARG_COUNT];
352
353 int nameCursor = INARG_LIMIT;
354 for (int i = 0; i < INARG_COUNT; i++) {
355 Object convSpec = convSpecs[i];
356 if (convSpec == null) {
357 // do nothing: difference is trivial
358 outArgs[OUTARG_BASE + i] = names[INARG_BASE + i];
359 continue;
360 }
361
362 Name conv;
363 if (convSpec instanceof Class) {
364 Class<?> convClass = (Class<?>) convSpec;
365 conv = new Name(getConstantHandle(MH_cast), convClass, names[INARG_BASE + i]);
366 } else {
367 MethodHandle fn = (MethodHandle) convSpec;
368 conv = new Name(fn, names[INARG_BASE + i]);
369 }
370 assert(names[nameCursor] == null);
371 names[nameCursor++] = conv;
372 assert(outArgs[OUTARG_BASE + i] == null);
373 outArgs[OUTARG_BASE + i] = conv;
374 }
375
376 // Build argument array for the call.
377 assert(nameCursor == OUT_CALL);
378 names[OUT_CALL] = new Name(target, outArgs);
379
380 Object convSpec = convSpecs[INARG_COUNT];
381 if (!retConv) {
382 assert(OUT_CALL == names.length-1);
383 } else {
384 Name conv;
385 if (convSpec == void.class) {
386 conv = new Name(LambdaForm.constantZero(BasicType.basicType(srcType.returnType())));
387 } else if (convSpec instanceof Class) {
388 Class<?> convClass = (Class<?>) convSpec;
389 conv = new Name(getConstantHandle(MH_cast), convClass, names[OUT_CALL]);
390 } else {
391 MethodHandle fn = (MethodHandle) convSpec;
392 if (fn.type().parameterCount() == 0)
393 conv = new Name(fn); // don't pass retval to void conversion
394 else
395 conv = new Name(fn, names[OUT_CALL]);
396 }
397 assert(names[RETURN_CONV] == null);
398 names[RETURN_CONV] = conv;
399 assert(RETURN_CONV == names.length-1);
400 }
401
402 LambdaForm form = new LambdaForm(lambdaType.parameterCount(), names, RESULT, Kind.CONVERT);
403 return SimpleMethodHandle.make(srcType, form);
404 }
405
406 static Object[] computeValueConversions(MethodType srcType, MethodType dstType,
407 boolean strict, boolean monobox) {
408 final int INARG_COUNT = srcType.parameterCount();
409 Object[] convSpecs = new Object[INARG_COUNT+1];
410 for (int i = 0; i <= INARG_COUNT; i++) {
411 boolean isRet = (i == INARG_COUNT);
412 Class<?> src = isRet ? dstType.returnType() : srcType.parameterType(i);
413 Class<?> dst = isRet ? srcType.returnType() : dstType.parameterType(i);
414 if (!VerifyType.isNullConversion(src, dst, /*keepInterfaces=*/ strict)) {
415 convSpecs[i] = valueConversion(src, dst, strict, monobox);
416 }
417 }
418 return convSpecs;
419 }
420 static MethodHandle makePairwiseConvert(MethodHandle target, MethodType srcType,
421 boolean strict) {
422 return makePairwiseConvert(target, srcType, strict, /*monobox=*/ false);
423 }
424
425 /**
426 * Find a conversion function from the given source to the given destination.
427 * This conversion function will be used as a LF NamedFunction.
428 * Return a Class object if a simple cast is needed.
429 * Return void.class if void is involved.
430 */
431 static Object valueConversion(Class<?> src, Class<?> dst, boolean strict, boolean monobox) {
432 assert(!VerifyType.isNullConversion(src, dst, /*keepInterfaces=*/ strict)); // caller responsibility
433 if (dst == void.class)
434 return dst;
435 MethodHandle fn;
436 if (src.isPrimitive()) {
437 if (src == void.class) {
438 return void.class; // caller must recognize this specially
439 } else if (dst.isPrimitive()) {
440 // Examples: int->byte, byte->int, boolean->int (!strict)
441 fn = ValueConversions.convertPrimitive(src, dst);
442 } else {
443 // Examples: int->Integer, boolean->Object, float->Number
444 Wrapper wsrc = Wrapper.forPrimitiveType(src);
445 fn = ValueConversions.boxExact(wsrc);
446 assert(fn.type().parameterType(0) == wsrc.primitiveType());
447 assert(fn.type().returnType() == wsrc.wrapperType());
448 if (!VerifyType.isNullConversion(wsrc.wrapperType(), dst, strict)) {
449 // Corner case, such as int->Long, which will probably fail.
450 MethodType mt = MethodType.methodType(dst, src);
451 if (strict)
452 fn = fn.asType(mt);
453 else
454 fn = MethodHandleImpl.makePairwiseConvert(fn, mt, /*strict=*/ false);
455 }
456 }
457 } else if (dst.isPrimitive()) {
458 Wrapper wdst = Wrapper.forPrimitiveType(dst);
459 if (monobox || src == wdst.wrapperType()) {
460 // Use a strongly-typed unboxer, if possible.
461 fn = ValueConversions.unboxExact(wdst, strict);
462 } else {
463 // Examples: Object->int, Number->int, Comparable->int, Byte->int
464 // must include additional conversions
465 // src must be examined at runtime, to detect Byte, Character, etc.
466 fn = (strict
467 ? ValueConversions.unboxWiden(wdst)
468 : ValueConversions.unboxCast(wdst));
469 }
470 } else {
471 // Simple reference conversion.
472 // Note: Do not check for a class hierarchy relation
473 // between src and dst. In all cases a 'null' argument
474 // will pass the cast conversion.
475 return dst;
476 }
477 assert(fn.type().parameterCount() <= 1) : "pc"+Arrays.asList(src.getSimpleName(), dst.getSimpleName(), fn);
478 return fn;
479 }
480
481 static MethodHandle makeVarargsCollector(MethodHandle target, Class<?> arrayType) {
482 MethodType type = target.type();
483 int last = type.parameterCount() - 1;
484 if (type.parameterType(last) != arrayType)
485 target = target.asType(type.changeParameterType(last, arrayType));
486 target = target.asFixedArity(); // make sure this attribute is turned off
487 return new AsVarargsCollector(target, arrayType);
488 }
489
490 private static final class AsVarargsCollector extends DelegatingMethodHandle {
491 private final MethodHandle target;
492 private final Class<?> arrayType;
493 private @Stable MethodHandle asCollectorCache;
494
495 AsVarargsCollector(MethodHandle target, Class<?> arrayType) {
496 this(target.type(), target, arrayType);
497 }
498 AsVarargsCollector(MethodType type, MethodHandle target, Class<?> arrayType) {
499 super(type, target);
500 this.target = target;
501 this.arrayType = arrayType;
502 this.asCollectorCache = target.asCollector(arrayType, 0);
503 }
504
505 @Override
506 public boolean isVarargsCollector() {
507 return true;
508 }
509
510 @Override
511 protected MethodHandle getTarget() {
512 return target;
513 }
514
515 @Override
516 public MethodHandle asFixedArity() {
517 return target;
518 }
519
520 @Override
521 MethodHandle setVarargs(MemberName member) {
522 if (member.isVarargs()) return this;
523 return asFixedArity();
524 }
525
526 @Override
527 public MethodHandle withVarargs(boolean makeVarargs) {
528 if (makeVarargs) return this;
529 return asFixedArity();
530 }
531
532 @Override
533 public MethodHandle asTypeUncached(MethodType newType) {
534 MethodType type = this.type();
535 int collectArg = type.parameterCount() - 1;
536 int newArity = newType.parameterCount();
537 if (newArity == collectArg+1 &&
538 type.parameterType(collectArg).isAssignableFrom(newType.parameterType(collectArg))) {
539 // if arity and trailing parameter are compatible, do normal thing
540 return asTypeCache = asFixedArity().asType(newType);
541 }
542 // check cache
543 MethodHandle acc = asCollectorCache;
544 if (acc != null && acc.type().parameterCount() == newArity)
545 return asTypeCache = acc.asType(newType);
546 // build and cache a collector
547 int arrayLength = newArity - collectArg;
548 MethodHandle collector;
549 try {
550 collector = asFixedArity().asCollector(arrayType, arrayLength);
551 assert(collector.type().parameterCount() == newArity) : "newArity="+newArity+" but collector="+collector;
552 } catch (IllegalArgumentException ex) {
553 throw new WrongMethodTypeException("cannot build collector", ex);
554 }
555 asCollectorCache = collector;
556 return asTypeCache = collector.asType(newType);
557 }
558
559 @Override
560 boolean viewAsTypeChecks(MethodType newType, boolean strict) {
561 super.viewAsTypeChecks(newType, true);
562 if (strict) return true;
563 // extra assertion for non-strict checks:
564 assert (type().lastParameterType().getComponentType()
565 .isAssignableFrom(
566 newType.lastParameterType().getComponentType()))
567 : Arrays.asList(this, newType);
568 return true;
569 }
570
571 @Override
572 public Object invokeWithArguments(Object... arguments) throws Throwable {
573 MethodType type = this.type();
574 int argc;
575 final int MAX_SAFE = 127; // 127 longs require 254 slots, which is safe to spread
576 if (arguments == null
577 || (argc = arguments.length) <= MAX_SAFE
578 || argc < type.parameterCount()) {
579 return super.invokeWithArguments(arguments);
580 }
581
582 // a jumbo invocation requires more explicit reboxing of the trailing arguments
583 int uncollected = type.parameterCount() - 1;
584 Class<?> elemType = arrayType.getComponentType();
585 int collected = argc - uncollected;
586 Object collArgs = (elemType == Object.class)
587 ? new Object[collected] : Array.newInstance(elemType, collected);
588 if (!elemType.isPrimitive()) {
589 // simple cast: just do some casting
590 try {
591 System.arraycopy(arguments, uncollected, collArgs, 0, collected);
592 } catch (ArrayStoreException ex) {
593 return super.invokeWithArguments(arguments);
594 }
595 } else {
596 // corner case of flat array requires reflection (or specialized copy loop)
597 MethodHandle arraySetter = MethodHandles.arrayElementSetter(arrayType);
598 try {
599 for (int i = 0; i < collected; i++) {
600 arraySetter.invoke(collArgs, i, arguments[uncollected + i]);
601 }
602 } catch (WrongMethodTypeException|ClassCastException ex) {
603 return super.invokeWithArguments(arguments);
604 }
605 }
606
607 // chop the jumbo list down to size and call in non-varargs mode
608 Object[] newArgs = new Object[uncollected + 1];
609 System.arraycopy(arguments, 0, newArgs, 0, uncollected);
610 newArgs[uncollected] = collArgs;
611 return asFixedArity().invokeWithArguments(newArgs);
612 }
613 }
614
615 /** Factory method: Spread selected argument. */
616 static MethodHandle makeSpreadArguments(MethodHandle target,
617 Class<?> spreadArgType, int spreadArgPos, int spreadArgCount) {
618 MethodType targetType = target.type();
619
620 for (int i = 0; i < spreadArgCount; i++) {
621 Class<?> arg = VerifyType.spreadArgElementType(spreadArgType, i);
622 if (arg == null) arg = Object.class;
623 targetType = targetType.changeParameterType(spreadArgPos + i, arg);
624 }
625 target = target.asType(targetType);
626
627 MethodType srcType = targetType
628 .replaceParameterTypes(spreadArgPos, spreadArgPos + spreadArgCount, spreadArgType);
629 // Now build a LambdaForm.
630 MethodType lambdaType = srcType.invokerType();
631 Name[] names = arguments(spreadArgCount + 2, lambdaType);
632 int nameCursor = lambdaType.parameterCount();
633 int[] indexes = new int[targetType.parameterCount()];
634
635 for (int i = 0, argIndex = 1; i < targetType.parameterCount() + 1; i++, argIndex++) {
636 Class<?> src = lambdaType.parameterType(i);
637 if (i == spreadArgPos) {
638 // Spread the array.
639 MethodHandle aload = MethodHandles.arrayElementGetter(spreadArgType);
640 Name array = names[argIndex];
641 names[nameCursor++] = new Name(getFunction(NF_checkSpreadArgument), array, spreadArgCount);
642 for (int j = 0; j < spreadArgCount; i++, j++) {
643 indexes[i] = nameCursor;
644 names[nameCursor++] = new Name(new NamedFunction(aload, Intrinsic.ARRAY_LOAD), array, j);
645 }
646 } else if (i < indexes.length) {
647 indexes[i] = argIndex;
648 }
649 }
650 assert(nameCursor == names.length-1); // leave room for the final call
651
652 // Build argument array for the call.
653 Name[] targetArgs = new Name[targetType.parameterCount()];
654 for (int i = 0; i < targetType.parameterCount(); i++) {
655 int idx = indexes[i];
656 targetArgs[i] = names[idx];
657 }
658 names[names.length - 1] = new Name(target, (Object[]) targetArgs);
659
660 LambdaForm form = new LambdaForm(lambdaType.parameterCount(), names, Kind.SPREAD);
661 return SimpleMethodHandle.make(srcType, form);
662 }
663
664 static void checkSpreadArgument(Object av, int n) {
665 if (av == null) {
666 if (n == 0) return;
667 } else if (av instanceof Object[]) {
668 int len = ((Object[])av).length;
669 if (len == n) return;
670 } else {
671 int len = java.lang.reflect.Array.getLength(av);
672 if (len == n) return;
673 }
674 // fall through to error:
675 throw newIllegalArgumentException("array is not of length "+n);
676 }
677
678 /** Factory method: Collect or filter selected argument(s). */
679 static MethodHandle makeCollectArguments(MethodHandle target,
680 MethodHandle collector, int collectArgPos, boolean retainOriginalArgs) {
681 MethodType targetType = target.type(); // (a..., c, [b...])=>r
682 MethodType collectorType = collector.type(); // (b...)=>c
683 int collectArgCount = collectorType.parameterCount();
684 Class<?> collectValType = collectorType.returnType();
685 int collectValCount = (collectValType == void.class ? 0 : 1);
686 MethodType srcType = targetType // (a..., [b...])=>r
687 .dropParameterTypes(collectArgPos, collectArgPos+collectValCount);
688 if (!retainOriginalArgs) { // (a..., b...)=>r
689 srcType = srcType.insertParameterTypes(collectArgPos, collectorType.parameterArray());
690 }
691 // in arglist: [0: ...keep1 | cpos: collect... | cpos+cacount: keep2... ]
692 // out arglist: [0: ...keep1 | cpos: collectVal? | cpos+cvcount: keep2... ]
693 // out(retain): [0: ...keep1 | cpos: cV? coll... | cpos+cvc+cac: keep2... ]
694
695 // Now build a LambdaForm.
696 MethodType lambdaType = srcType.invokerType();
697 Name[] names = arguments(2, lambdaType);
698 final int collectNamePos = names.length - 2;
699 final int targetNamePos = names.length - 1;
700
701 Name[] collectorArgs = Arrays.copyOfRange(names, 1 + collectArgPos, 1 + collectArgPos + collectArgCount);
702 names[collectNamePos] = new Name(collector, (Object[]) collectorArgs);
703
704 // Build argument array for the target.
705 // Incoming LF args to copy are: [ (mh) headArgs collectArgs tailArgs ].
706 // Output argument array is [ headArgs (collectVal)? (collectArgs)? tailArgs ].
707 Name[] targetArgs = new Name[targetType.parameterCount()];
708 int inputArgPos = 1; // incoming LF args to copy to target
709 int targetArgPos = 0; // fill pointer for targetArgs
710 int chunk = collectArgPos; // |headArgs|
711 System.arraycopy(names, inputArgPos, targetArgs, targetArgPos, chunk);
712 inputArgPos += chunk;
713 targetArgPos += chunk;
714 if (collectValType != void.class) {
715 targetArgs[targetArgPos++] = names[collectNamePos];
716 }
717 chunk = collectArgCount;
718 if (retainOriginalArgs) {
719 System.arraycopy(names, inputArgPos, targetArgs, targetArgPos, chunk);
720 targetArgPos += chunk; // optionally pass on the collected chunk
721 }
722 inputArgPos += chunk;
723 chunk = targetArgs.length - targetArgPos; // all the rest
724 System.arraycopy(names, inputArgPos, targetArgs, targetArgPos, chunk);
725 assert(inputArgPos + chunk == collectNamePos); // use of rest of input args also
726 names[targetNamePos] = new Name(target, (Object[]) targetArgs);
727
728 LambdaForm form = new LambdaForm(lambdaType.parameterCount(), names, Kind.COLLECT);
729 return SimpleMethodHandle.make(srcType, form);
730 }
731
732 @LambdaForm.Hidden
733 static
734 MethodHandle selectAlternative(boolean testResult, MethodHandle target, MethodHandle fallback) {
735 if (testResult) {
736 return target;
737 } else {
738 return fallback;
739 }
740 }
741
742 // Intrinsified by C2. Counters are used during parsing to calculate branch frequencies.
743 @LambdaForm.Hidden
744 @jdk.internal.HotSpotIntrinsicCandidate
745 static
746 boolean profileBoolean(boolean result, int[] counters) {
747 // Profile is int[2] where [0] and [1] correspond to false and true occurrences respectively.
748 int idx = result ? 1 : 0;
749 try {
750 counters[idx] = Math.addExact(counters[idx], 1);
751 } catch (ArithmeticException e) {
752 // Avoid continuous overflow by halving the problematic count.
753 counters[idx] = counters[idx] / 2;
754 }
755 return result;
756 }
757
758 // Intrinsified by C2. Returns true if obj is a compile-time constant.
759 @LambdaForm.Hidden
760 @jdk.internal.HotSpotIntrinsicCandidate
761 static
762 boolean isCompileConstant(Object obj) {
763 return false;
764 }
765
766 static
767 MethodHandle makeGuardWithTest(MethodHandle test,
768 MethodHandle target,
769 MethodHandle fallback) {
770 MethodType type = target.type();
771 assert(test.type().equals(type.changeReturnType(boolean.class)) && fallback.type().equals(type));
772 MethodType basicType = type.basicType();
773 LambdaForm form = makeGuardWithTestForm(basicType);
774 BoundMethodHandle mh;
775 try {
776 if (PROFILE_GWT) {
777 int[] counts = new int[2];
778 mh = (BoundMethodHandle)
779 BoundMethodHandle.speciesData_LLLL().constructor().invokeBasic(type, form,
780 (Object) test, (Object) profile(target), (Object) profile(fallback), counts);
781 } else {
782 mh = (BoundMethodHandle)
783 BoundMethodHandle.speciesData_LLL().constructor().invokeBasic(type, form,
784 (Object) test, (Object) profile(target), (Object) profile(fallback));
785 }
786 } catch (Throwable ex) {
787 throw uncaughtException(ex);
788 }
789 assert(mh.type() == type);
790 return mh;
791 }
792
793
794 static
795 MethodHandle profile(MethodHandle target) {
796 if (DONT_INLINE_THRESHOLD >= 0) {
797 return makeBlockInliningWrapper(target);
798 } else {
799 return target;
800 }
801 }
802
803 /**
804 * Block inlining during JIT-compilation of a target method handle if it hasn't been invoked enough times.
805 * Corresponding LambdaForm has @DontInline when compiled into bytecode.
806 */
807 static
808 MethodHandle makeBlockInliningWrapper(MethodHandle target) {
809 LambdaForm lform;
810 if (DONT_INLINE_THRESHOLD > 0) {
811 lform = Makers.PRODUCE_BLOCK_INLINING_FORM.apply(target);
812 } else {
813 lform = Makers.PRODUCE_REINVOKER_FORM.apply(target);
814 }
815 return new CountingWrapper(target, lform,
816 Makers.PRODUCE_BLOCK_INLINING_FORM, Makers.PRODUCE_REINVOKER_FORM,
817 DONT_INLINE_THRESHOLD);
818 }
819
820 private final static class Makers {
821 /** Constructs reinvoker lambda form which block inlining during JIT-compilation for a particular method handle */
822 static final Function<MethodHandle, LambdaForm> PRODUCE_BLOCK_INLINING_FORM = new Function<MethodHandle, LambdaForm>() {
823 @Override
824 public LambdaForm apply(MethodHandle target) {
825 return DelegatingMethodHandle.makeReinvokerForm(target,
826 MethodTypeForm.LF_DELEGATE_BLOCK_INLINING, CountingWrapper.class, false,
827 DelegatingMethodHandle.NF_getTarget, CountingWrapper.NF_maybeStopCounting);
828 }
829 };
830
831 /** Constructs simple reinvoker lambda form for a particular method handle */
832 static final Function<MethodHandle, LambdaForm> PRODUCE_REINVOKER_FORM = new Function<MethodHandle, LambdaForm>() {
833 @Override
834 public LambdaForm apply(MethodHandle target) {
835 return DelegatingMethodHandle.makeReinvokerForm(target,
836 MethodTypeForm.LF_DELEGATE, DelegatingMethodHandle.class, DelegatingMethodHandle.NF_getTarget);
837 }
838 };
839
840 /** Maker of type-polymorphic varargs */
841 static final ClassValue<MethodHandle[]> TYPED_COLLECTORS = new ClassValue<MethodHandle[]>() {
842 @Override
843 protected MethodHandle[] computeValue(Class<?> type) {
844 return new MethodHandle[MAX_JVM_ARITY + 1];
845 }
846 };
847 }
848
849 /**
850 * Counting method handle. It has 2 states: counting and non-counting.
851 * It is in counting state for the first n invocations and then transitions to non-counting state.
852 * Behavior in counting and non-counting states is determined by lambda forms produced by
853 * countingFormProducer & nonCountingFormProducer respectively.
854 */
855 static class CountingWrapper extends DelegatingMethodHandle {
856 private final MethodHandle target;
857 private int count;
858 private Function<MethodHandle, LambdaForm> countingFormProducer;
859 private Function<MethodHandle, LambdaForm> nonCountingFormProducer;
860 private volatile boolean isCounting;
861
862 private CountingWrapper(MethodHandle target, LambdaForm lform,
863 Function<MethodHandle, LambdaForm> countingFromProducer,
864 Function<MethodHandle, LambdaForm> nonCountingFormProducer,
865 int count) {
866 super(target.type(), lform);
867 this.target = target;
868 this.count = count;
869 this.countingFormProducer = countingFromProducer;
870 this.nonCountingFormProducer = nonCountingFormProducer;
871 this.isCounting = (count > 0);
872 }
873
874 @Hidden
875 @Override
876 protected MethodHandle getTarget() {
877 return target;
878 }
879
880 @Override
881 public MethodHandle asTypeUncached(MethodType newType) {
882 MethodHandle newTarget = target.asType(newType);
883 MethodHandle wrapper;
884 if (isCounting) {
885 LambdaForm lform;
886 lform = countingFormProducer.apply(newTarget);
887 wrapper = new CountingWrapper(newTarget, lform, countingFormProducer, nonCountingFormProducer, DONT_INLINE_THRESHOLD);
888 } else {
889 wrapper = newTarget; // no need for a counting wrapper anymore
890 }
891 return (asTypeCache = wrapper);
892 }
893
894 // Customize target if counting happens for too long.
895 private int invocations = CUSTOMIZE_THRESHOLD;
896 private void maybeCustomizeTarget() {
897 int c = invocations;
898 if (c >= 0) {
899 if (c == 1) {
900 target.customize();
901 }
902 invocations = c - 1;
903 }
904 }
905
906 boolean countDown() {
907 int c = count;
908 maybeCustomizeTarget();
909 if (c <= 1) {
910 // Try to limit number of updates. MethodHandle.updateForm() doesn't guarantee LF update visibility.
911 if (isCounting) {
912 isCounting = false;
913 return true;
914 } else {
915 return false;
916 }
917 } else {
918 count = c - 1;
919 return false;
920 }
921 }
922
923 @Hidden
924 static void maybeStopCounting(Object o1) {
925 CountingWrapper wrapper = (CountingWrapper) o1;
926 if (wrapper.countDown()) {
927 // Reached invocation threshold. Replace counting behavior with a non-counting one.
928 LambdaForm lform = wrapper.nonCountingFormProducer.apply(wrapper.target);
929 lform.compileToBytecode(); // speed up warmup by avoiding LF interpretation again after transition
930 wrapper.updateForm(lform);
931 }
932 }
933
934 static final NamedFunction NF_maybeStopCounting;
935 static {
936 Class<?> THIS_CLASS = CountingWrapper.class;
937 try {
938 NF_maybeStopCounting = new NamedFunction(THIS_CLASS.getDeclaredMethod("maybeStopCounting", Object.class));
939 } catch (ReflectiveOperationException ex) {
940 throw newInternalError(ex);
941 }
942 }
943 }
944
945 static
946 LambdaForm makeGuardWithTestForm(MethodType basicType) {
947 LambdaForm lform = basicType.form().cachedLambdaForm(MethodTypeForm.LF_GWT);
948 if (lform != null) return lform;
949 final int THIS_MH = 0; // the BMH_LLL
950 final int ARG_BASE = 1; // start of incoming arguments
951 final int ARG_LIMIT = ARG_BASE + basicType.parameterCount();
952 int nameCursor = ARG_LIMIT;
953 final int GET_TEST = nameCursor++;
954 final int GET_TARGET = nameCursor++;
955 final int GET_FALLBACK = nameCursor++;
956 final int GET_COUNTERS = PROFILE_GWT ? nameCursor++ : -1;
957 final int CALL_TEST = nameCursor++;
958 final int PROFILE = (GET_COUNTERS != -1) ? nameCursor++ : -1;
959 final int TEST = nameCursor-1; // previous statement: either PROFILE or CALL_TEST
960 final int SELECT_ALT = nameCursor++;
961 final int CALL_TARGET = nameCursor++;
962 assert(CALL_TARGET == SELECT_ALT+1); // must be true to trigger IBG.emitSelectAlternative
963
964 MethodType lambdaType = basicType.invokerType();
965 Name[] names = arguments(nameCursor - ARG_LIMIT, lambdaType);
966
967 BoundMethodHandle.SpeciesData data =
968 (GET_COUNTERS != -1) ? BoundMethodHandle.speciesData_LLLL()
969 : BoundMethodHandle.speciesData_LLL();
970 names[THIS_MH] = names[THIS_MH].withConstraint(data);
971 names[GET_TEST] = new Name(data.getterFunction(0), names[THIS_MH]);
972 names[GET_TARGET] = new Name(data.getterFunction(1), names[THIS_MH]);
973 names[GET_FALLBACK] = new Name(data.getterFunction(2), names[THIS_MH]);
974 if (GET_COUNTERS != -1) {
975 names[GET_COUNTERS] = new Name(data.getterFunction(3), names[THIS_MH]);
976 }
977 Object[] invokeArgs = Arrays.copyOfRange(names, 0, ARG_LIMIT, Object[].class);
978
979 // call test
980 MethodType testType = basicType.changeReturnType(boolean.class).basicType();
981 invokeArgs[0] = names[GET_TEST];
982 names[CALL_TEST] = new Name(testType, invokeArgs);
983
984 // profile branch
985 if (PROFILE != -1) {
986 names[PROFILE] = new Name(getFunction(NF_profileBoolean), names[CALL_TEST], names[GET_COUNTERS]);
987 }
988 // call selectAlternative
989 names[SELECT_ALT] = new Name(new NamedFunction(getConstantHandle(MH_selectAlternative), Intrinsic.SELECT_ALTERNATIVE), names[TEST], names[GET_TARGET], names[GET_FALLBACK]);
990
991 // call target or fallback
992 invokeArgs[0] = names[SELECT_ALT];
993 names[CALL_TARGET] = new Name(basicType, invokeArgs);
994
995 lform = new LambdaForm(lambdaType.parameterCount(), names, /*forceInline=*/true, Kind.GUARD);
996
997 return basicType.form().setCachedLambdaForm(MethodTypeForm.LF_GWT, lform);
998 }
999
1000 /**
1001 * The LambdaForm shape for catchException combinator is the following:
1002 * <blockquote><pre>{@code
1003 * guardWithCatch=Lambda(a0:L,a1:L,a2:L)=>{
1004 * t3:L=BoundMethodHandle$Species_LLLLL.argL0(a0:L);
1005 * t4:L=BoundMethodHandle$Species_LLLLL.argL1(a0:L);
1006 * t5:L=BoundMethodHandle$Species_LLLLL.argL2(a0:L);
1007 * t6:L=BoundMethodHandle$Species_LLLLL.argL3(a0:L);
1008 * t7:L=BoundMethodHandle$Species_LLLLL.argL4(a0:L);
1009 * t8:L=MethodHandle.invokeBasic(t6:L,a1:L,a2:L);
1010 * t9:L=MethodHandleImpl.guardWithCatch(t3:L,t4:L,t5:L,t8:L);
1011 * t10:I=MethodHandle.invokeBasic(t7:L,t9:L);t10:I}
1012 * }</pre></blockquote>
1013 *
1014 * argL0 and argL2 are target and catcher method handles. argL1 is exception class.
1015 * argL3 and argL4 are auxiliary method handles: argL3 boxes arguments and wraps them into Object[]
1016 * (ValueConversions.array()) and argL4 unboxes result if necessary (ValueConversions.unbox()).
1017 *
1018 * Having t8 and t10 passed outside and not hardcoded into a lambda form allows to share lambda forms
1019 * among catchException combinators with the same basic type.
1020 */
1021 private static LambdaForm makeGuardWithCatchForm(MethodType basicType) {
1022 MethodType lambdaType = basicType.invokerType();
1023
1024 LambdaForm lform = basicType.form().cachedLambdaForm(MethodTypeForm.LF_GWC);
1025 if (lform != null) {
1026 return lform;
1027 }
1028 final int THIS_MH = 0; // the BMH_LLLLL
1029 final int ARG_BASE = 1; // start of incoming arguments
1030 final int ARG_LIMIT = ARG_BASE + basicType.parameterCount();
1031
1032 int nameCursor = ARG_LIMIT;
1033 final int GET_TARGET = nameCursor++;
1034 final int GET_CLASS = nameCursor++;
1035 final int GET_CATCHER = nameCursor++;
1036 final int GET_COLLECT_ARGS = nameCursor++;
1037 final int GET_UNBOX_RESULT = nameCursor++;
1038 final int BOXED_ARGS = nameCursor++;
1039 final int TRY_CATCH = nameCursor++;
1040 final int UNBOX_RESULT = nameCursor++;
1041
1042 Name[] names = arguments(nameCursor - ARG_LIMIT, lambdaType);
1043
1044 BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_LLLLL();
1045 names[THIS_MH] = names[THIS_MH].withConstraint(data);
1046 names[GET_TARGET] = new Name(data.getterFunction(0), names[THIS_MH]);
1047 names[GET_CLASS] = new Name(data.getterFunction(1), names[THIS_MH]);
1048 names[GET_CATCHER] = new Name(data.getterFunction(2), names[THIS_MH]);
1049 names[GET_COLLECT_ARGS] = new Name(data.getterFunction(3), names[THIS_MH]);
1050 names[GET_UNBOX_RESULT] = new Name(data.getterFunction(4), names[THIS_MH]);
1051
1052 // FIXME: rework argument boxing/result unboxing logic for LF interpretation
1053
1054 // t_{i}:L=MethodHandle.invokeBasic(collectArgs:L,a1:L,...);
1055 MethodType collectArgsType = basicType.changeReturnType(Object.class);
1056 MethodHandle invokeBasic = MethodHandles.basicInvoker(collectArgsType);
1057 Object[] args = new Object[invokeBasic.type().parameterCount()];
1058 args[0] = names[GET_COLLECT_ARGS];
1059 System.arraycopy(names, ARG_BASE, args, 1, ARG_LIMIT-ARG_BASE);
1060 names[BOXED_ARGS] = new Name(new NamedFunction(invokeBasic, Intrinsic.GUARD_WITH_CATCH), args);
1061
1062 // t_{i+1}:L=MethodHandleImpl.guardWithCatch(target:L,exType:L,catcher:L,t_{i}:L);
1063 Object[] gwcArgs = new Object[] {names[GET_TARGET], names[GET_CLASS], names[GET_CATCHER], names[BOXED_ARGS]};
1064 names[TRY_CATCH] = new Name(getFunction(NF_guardWithCatch), gwcArgs);
1065
1066 // t_{i+2}:I=MethodHandle.invokeBasic(unbox:L,t_{i+1}:L);
1067 MethodHandle invokeBasicUnbox = MethodHandles.basicInvoker(MethodType.methodType(basicType.rtype(), Object.class));
1068 Object[] unboxArgs = new Object[] {names[GET_UNBOX_RESULT], names[TRY_CATCH]};
1069 names[UNBOX_RESULT] = new Name(invokeBasicUnbox, unboxArgs);
1070
1071 lform = new LambdaForm(lambdaType.parameterCount(), names, Kind.GUARD_WITH_CATCH);
1072
1073 return basicType.form().setCachedLambdaForm(MethodTypeForm.LF_GWC, lform);
1074 }
1075
1076 static
1077 MethodHandle makeGuardWithCatch(MethodHandle target,
1078 Class<? extends Throwable> exType,
1079 MethodHandle catcher) {
1080 MethodType type = target.type();
1081 LambdaForm form = makeGuardWithCatchForm(type.basicType());
1082
1083 // Prepare auxiliary method handles used during LambdaForm interpretation.
1084 // Box arguments and wrap them into Object[]: ValueConversions.array().
1085 MethodType varargsType = type.changeReturnType(Object[].class);
1086 MethodHandle collectArgs = varargsArray(type.parameterCount()).asType(varargsType);
1087 MethodHandle unboxResult = unboxResultHandle(type.returnType());
1088
1089 BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_LLLLL();
1090 BoundMethodHandle mh;
1091 try {
1092 mh = (BoundMethodHandle) data.constructor().invokeBasic(type, form, (Object) target, (Object) exType,
1093 (Object) catcher, (Object) collectArgs, (Object) unboxResult);
1094 } catch (Throwable ex) {
1095 throw uncaughtException(ex);
1096 }
1097 assert(mh.type() == type);
1098 return mh;
1099 }
1100
1101 /**
1102 * Intrinsified during LambdaForm compilation
1103 * (see {@link InvokerBytecodeGenerator#emitGuardWithCatch emitGuardWithCatch}).
1104 */
1105 @LambdaForm.Hidden
1106 static Object guardWithCatch(MethodHandle target, Class<? extends Throwable> exType, MethodHandle catcher,
1107 Object... av) throws Throwable {
1108 // Use asFixedArity() to avoid unnecessary boxing of last argument for VarargsCollector case.
1109 try {
1110 return target.asFixedArity().invokeWithArguments(av);
1111 } catch (Throwable t) {
1112 if (!exType.isInstance(t)) throw t;
1113 return catcher.asFixedArity().invokeWithArguments(prepend(av, t));
1114 }
1115 }
1116
1117 /** Prepend elements to an array. */
1118 @LambdaForm.Hidden
1119 private static Object[] prepend(Object[] array, Object... elems) {
1120 int nArray = array.length;
1121 int nElems = elems.length;
1122 Object[] newArray = new Object[nArray + nElems];
1123 System.arraycopy(elems, 0, newArray, 0, nElems);
1124 System.arraycopy(array, 0, newArray, nElems, nArray);
1125 return newArray;
1126 }
1127
1128 static
1129 MethodHandle throwException(MethodType type) {
1130 assert(Throwable.class.isAssignableFrom(type.parameterType(0)));
1131 int arity = type.parameterCount();
1132 if (arity > 1) {
1133 MethodHandle mh = throwException(type.dropParameterTypes(1, arity));
1134 mh = MethodHandles.dropArguments(mh, 1, Arrays.copyOfRange(type.parameterArray(), 1, arity));
1135 return mh;
1136 }
1137 return makePairwiseConvert(getFunction(NF_throwException).resolvedHandle(), type, false, true);
1138 }
1139
1140 static <T extends Throwable> Empty throwException(T t) throws T { throw t; }
1141
1142 static MethodHandle[] FAKE_METHOD_HANDLE_INVOKE = new MethodHandle[2];
1143 static MethodHandle fakeMethodHandleInvoke(MemberName method) {
1144 int idx;
1145 assert(method.isMethodHandleInvoke());
1146 switch (method.getName()) {
1147 case "invoke": idx = 0; break;
1148 case "invokeExact": idx = 1; break;
1149 default: throw new InternalError(method.getName());
1150 }
1151 MethodHandle mh = FAKE_METHOD_HANDLE_INVOKE[idx];
1152 if (mh != null) return mh;
1153 MethodType type = MethodType.methodType(Object.class, UnsupportedOperationException.class,
1154 MethodHandle.class, Object[].class);
1155 mh = throwException(type);
1156 mh = mh.bindTo(new UnsupportedOperationException("cannot reflectively invoke MethodHandle"));
1157 if (!method.getInvocationType().equals(mh.type()))
1158 throw new InternalError(method.toString());
1159 mh = mh.withInternalMemberName(method, false);
1160 mh = mh.withVarargs(true);
1161 assert(method.isVarargs());
1162 FAKE_METHOD_HANDLE_INVOKE[idx] = mh;
1163 return mh;
1164 }
1165 static MethodHandle fakeVarHandleInvoke(MemberName method) {
1166 // TODO caching, is it necessary?
1167 MethodType type = MethodType.methodType(method.getReturnType(), UnsupportedOperationException.class,
1168 VarHandle.class, Object[].class);
1169 MethodHandle mh = throwException(type);
1170 mh = mh.bindTo(new UnsupportedOperationException("cannot reflectively invoke VarHandle"));
1171 if (!method.getInvocationType().equals(mh.type()))
1172 throw new InternalError(method.toString());
1173 mh = mh.withInternalMemberName(method, false);
1174 mh = mh.asVarargsCollector(Object[].class);
1175 assert(method.isVarargs());
1176 return mh;
1177 }
1178
1179 /**
1180 * Create an alias for the method handle which, when called,
1181 * appears to be called from the same class loader and protection domain
1182 * as hostClass.
1183 * This is an expensive no-op unless the method which is called
1184 * is sensitive to its caller. A small number of system methods
1185 * are in this category, including Class.forName and Method.invoke.
1186 */
1187 static
1188 MethodHandle bindCaller(MethodHandle mh, Class<?> hostClass) {
1189 return BindCaller.bindCaller(mh, hostClass);
1190 }
1191
1192 // Put the whole mess into its own nested class.
1193 // That way we can lazily load the code and set up the constants.
1194 private static class BindCaller {
1195 private static MethodType INVOKER_MT = MethodType.methodType(Object.class, MethodHandle.class, Object[].class);
1196
1197 static
1198 MethodHandle bindCaller(MethodHandle mh, Class<?> hostClass) {
1199 // Code in the boot layer should now be careful while creating method handles or
1200 // functional interface instances created from method references to @CallerSensitive methods,
1201 // it needs to be ensured the handles or interface instances are kept safe and are not passed
1202 // from the boot layer to untrusted code.
1203 if (hostClass == null
1204 || (hostClass.isArray() ||
1205 hostClass.isPrimitive() ||
1206 hostClass.getName().startsWith("java.lang.invoke."))) {
1207 throw new InternalError(); // does not happen, and should not anyway
1208 }
1209 // For simplicity, convert mh to a varargs-like method.
1210 MethodHandle vamh = prepareForInvoker(mh);
1211 // Cache the result of makeInjectedInvoker once per argument class.
1212 MethodHandle bccInvoker = CV_makeInjectedInvoker.get(hostClass);
1213 return restoreToType(bccInvoker.bindTo(vamh), mh, hostClass);
1214 }
1215
1216 private static MethodHandle makeInjectedInvoker(Class<?> hostClass) {
1217 try {
1218 Class<?> invokerClass = UNSAFE.defineAnonymousClass(hostClass, INJECTED_INVOKER_TEMPLATE, null);
1219 assert checkInjectedInvoker(hostClass, invokerClass);
1220 return IMPL_LOOKUP.findStatic(invokerClass, "invoke_V", INVOKER_MT);
1221 } catch (ReflectiveOperationException ex) {
1222 throw uncaughtException(ex);
1223 }
1224 }
1225
1226 private static ClassValue<MethodHandle> CV_makeInjectedInvoker = new ClassValue<MethodHandle>() {
1227 @Override protected MethodHandle computeValue(Class<?> hostClass) {
1228 return makeInjectedInvoker(hostClass);
1229 }
1230 };
1231
1232 // Adapt mh so that it can be called directly from an injected invoker:
1233 private static MethodHandle prepareForInvoker(MethodHandle mh) {
1234 mh = mh.asFixedArity();
1235 MethodType mt = mh.type();
1236 int arity = mt.parameterCount();
1237 MethodHandle vamh = mh.asType(mt.generic());
1238 vamh.internalForm().compileToBytecode(); // eliminate LFI stack frames
1239 vamh = vamh.asSpreader(Object[].class, arity);
1240 vamh.internalForm().compileToBytecode(); // eliminate LFI stack frames
1241 return vamh;
1242 }
1243
1244 // Undo the adapter effect of prepareForInvoker:
1245 private static MethodHandle restoreToType(MethodHandle vamh,
1246 MethodHandle original,
1247 Class<?> hostClass) {
1248 MethodType type = original.type();
1249 MethodHandle mh = vamh.asCollector(Object[].class, type.parameterCount());
1250 MemberName member = original.internalMemberName();
1251 mh = mh.asType(type);
1252 mh = new WrappedMember(mh, type, member, original.isInvokeSpecial(), hostClass);
1253 return mh;
1254 }
1255
1256 private static boolean checkInjectedInvoker(Class<?> hostClass, Class<?> invokerClass) {
1257 assert (hostClass.getClassLoader() == invokerClass.getClassLoader()) : hostClass.getName()+" (CL)";
1258 try {
1259 assert (hostClass.getProtectionDomain() == invokerClass.getProtectionDomain()) : hostClass.getName()+" (PD)";
1260 } catch (SecurityException ex) {
1261 // Self-check was blocked by security manager. This is OK.
1262 }
1263 try {
1264 // Test the invoker to ensure that it really injects into the right place.
1265 MethodHandle invoker = IMPL_LOOKUP.findStatic(invokerClass, "invoke_V", INVOKER_MT);
1266 MethodHandle vamh = prepareForInvoker(MH_checkCallerClass);
1267 return (boolean)invoker.invoke(vamh, new Object[]{ invokerClass });
1268 } catch (Throwable ex) {
1269 throw new InternalError(ex);
1270 }
1271 }
1272
1273 private static final MethodHandle MH_checkCallerClass;
1274 static {
1275 final Class<?> THIS_CLASS = BindCaller.class;
1276 assert(checkCallerClass(THIS_CLASS));
1277 try {
1278 MH_checkCallerClass = IMPL_LOOKUP
1279 .findStatic(THIS_CLASS, "checkCallerClass",
1280 MethodType.methodType(boolean.class, Class.class));
1281 assert((boolean) MH_checkCallerClass.invokeExact(THIS_CLASS));
1282 } catch (Throwable ex) {
1283 throw new InternalError(ex);
1284 }
1285 }
1286
1287 @CallerSensitive
1288 @ForceInline // to ensure Reflection.getCallerClass optimization
1289 private static boolean checkCallerClass(Class<?> expected) {
1290 // This method is called via MH_checkCallerClass and so it's correct to ask for the immediate caller here.
1291 Class<?> actual = Reflection.getCallerClass();
1292 if (actual != expected)
1293 throw new InternalError("found " + actual.getName() + ", expected " + expected.getName());
1294 return true;
1295 }
1296
1297 private static final byte[] INJECTED_INVOKER_TEMPLATE = generateInvokerTemplate();
1298
1299 /** Produces byte code for a class that is used as an injected invoker. */
1300 private static byte[] generateInvokerTemplate() {
1301 ClassWriter cw = new ClassWriter(0);
1302
1303 // private static class InjectedInvoker {
1304 // @Hidden
1305 // static Object invoke_V(MethodHandle vamh, Object[] args) throws Throwable {
1306 // return vamh.invokeExact(args);
1307 // }
1308 // }
1309 cw.visit(52, ACC_PRIVATE | ACC_SUPER, "InjectedInvoker", null, "java/lang/Object", null);
1310
1311 MethodVisitor mv = cw.visitMethod(ACC_STATIC, "invoke_V",
1312 "(Ljava/lang/invoke/MethodHandle;[Ljava/lang/Object;)Ljava/lang/Object;",
1313 null, null);
1314
1315 // Suppress invoker method in stack traces.
1316 AnnotationVisitor av0 = mv.visitAnnotation("Ljava/lang/invoke/LambdaForm$Hidden;", true);
1317 av0.visitEnd();
1318
1319 mv.visitCode();
1320 mv.visitVarInsn(ALOAD, 0);
1321 mv.visitVarInsn(ALOAD, 1);
1322 mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/invoke/MethodHandle", "invokeExact",
1323 "([Ljava/lang/Object;)Ljava/lang/Object;", false);
1324 mv.visitInsn(ARETURN);
1325 mv.visitMaxs(2, 2);
1326 mv.visitEnd();
1327
1328 cw.visitEnd();
1329 return cw.toByteArray();
1330 }
1331 }
1332
1333 /** This subclass allows a wrapped method handle to be re-associated with an arbitrary member name. */
1334 private static final class WrappedMember extends DelegatingMethodHandle {
1335 private final MethodHandle target;
1336 private final MemberName member;
1337 private final Class<?> callerClass;
1338 private final boolean isInvokeSpecial;
1339
1340 private WrappedMember(MethodHandle target, MethodType type,
1341 MemberName member, boolean isInvokeSpecial,
1342 Class<?> callerClass) {
1343 super(type, target);
1344 this.target = target;
1345 this.member = member;
1346 this.callerClass = callerClass;
1347 this.isInvokeSpecial = isInvokeSpecial;
1348 }
1349
1350 @Override
1351 MemberName internalMemberName() {
1352 return member;
1353 }
1354 @Override
1355 Class<?> internalCallerClass() {
1356 return callerClass;
1357 }
1358 @Override
1359 boolean isInvokeSpecial() {
1360 return isInvokeSpecial;
1361 }
1362 @Override
1363 protected MethodHandle getTarget() {
1364 return target;
1365 }
1366 @Override
1367 public MethodHandle asTypeUncached(MethodType newType) {
1368 // This MH is an alias for target, except for the MemberName
1369 // Drop the MemberName if there is any conversion.
1370 return asTypeCache = target.asType(newType);
1371 }
1372 }
1373
1374 static MethodHandle makeWrappedMember(MethodHandle target, MemberName member, boolean isInvokeSpecial) {
1375 if (member.equals(target.internalMemberName()) && isInvokeSpecial == target.isInvokeSpecial())
1376 return target;
1377 return new WrappedMember(target, target.type(), member, isInvokeSpecial, null);
1378 }
1379
1380 /** Intrinsic IDs */
1381 /*non-public*/
1382 enum Intrinsic {
1383 SELECT_ALTERNATIVE,
1384 GUARD_WITH_CATCH,
1385 TRY_FINALLY,
1386 LOOP,
1387 NEW_ARRAY,
1388 ARRAY_LOAD,
1389 ARRAY_STORE,
1390 ARRAY_LENGTH,
1391 IDENTITY,
1392 ZERO,
1393 NONE // no intrinsic associated
1394 }
1395
1396 /** Mark arbitrary method handle as intrinsic.
1397 * InvokerBytecodeGenerator uses this info to produce more efficient bytecode shape. */
1398 static final class IntrinsicMethodHandle extends DelegatingMethodHandle {
1399 private final MethodHandle target;
1400 private final Intrinsic intrinsicName;
1401
1402 IntrinsicMethodHandle(MethodHandle target, Intrinsic intrinsicName) {
1403 super(target.type(), target);
1404 this.target = target;
1405 this.intrinsicName = intrinsicName;
1406 }
1407
1408 @Override
1409 protected MethodHandle getTarget() {
1410 return target;
1411 }
1412
1413 @Override
1414 Intrinsic intrinsicName() {
1415 return intrinsicName;
1416 }
1417
1418 @Override
1419 public MethodHandle asTypeUncached(MethodType newType) {
1420 // This MH is an alias for target, except for the intrinsic name
1421 // Drop the name if there is any conversion.
1422 return asTypeCache = target.asType(newType);
1423 }
1424
1425 @Override
1426 String internalProperties() {
1427 return super.internalProperties() +
1428 "\n& Intrinsic="+intrinsicName;
1429 }
1430
1431 @Override
1432 public MethodHandle asCollector(Class<?> arrayType, int arrayLength) {
1433 if (intrinsicName == Intrinsic.IDENTITY) {
1434 MethodType resultType = type().asCollectorType(arrayType, type().parameterCount() - 1, arrayLength);
1435 MethodHandle newArray = MethodHandleImpl.varargsArray(arrayType, arrayLength);
1436 return newArray.asType(resultType);
1437 }
1438 return super.asCollector(arrayType, arrayLength);
1439 }
1440 }
1441
1442 static MethodHandle makeIntrinsic(MethodHandle target, Intrinsic intrinsicName) {
1443 if (intrinsicName == target.intrinsicName())
1444 return target;
1445 return new IntrinsicMethodHandle(target, intrinsicName);
1446 }
1447
1448 static MethodHandle makeIntrinsic(MethodType type, LambdaForm form, Intrinsic intrinsicName) {
1449 return new IntrinsicMethodHandle(SimpleMethodHandle.make(type, form), intrinsicName);
1450 }
1451
1452 /// Collection of multiple arguments.
1453
1454 private static MethodHandle findCollector(String name, int nargs, Class<?> rtype, Class<?>... ptypes) {
1455 MethodType type = MethodType.genericMethodType(nargs)
1456 .changeReturnType(rtype)
1457 .insertParameterTypes(0, ptypes);
1458 try {
1459 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, name, type);
1460 } catch (ReflectiveOperationException ex) {
1461 return null;
1462 }
1463 }
1464
1465 private static final Object[] NO_ARGS_ARRAY = {};
1466 private static Object[] makeArray(Object... args) { return args; }
1467 private static Object[] array() { return NO_ARGS_ARRAY; }
1468 private static Object[] array(Object a0)
1469 { return makeArray(a0); }
1470 private static Object[] array(Object a0, Object a1)
1471 { return makeArray(a0, a1); }
1472 private static Object[] array(Object a0, Object a1, Object a2)
1473 { return makeArray(a0, a1, a2); }
1474 private static Object[] array(Object a0, Object a1, Object a2, Object a3)
1475 { return makeArray(a0, a1, a2, a3); }
1476 private static Object[] array(Object a0, Object a1, Object a2, Object a3,
1477 Object a4)
1478 { return makeArray(a0, a1, a2, a3, a4); }
1479 private static Object[] array(Object a0, Object a1, Object a2, Object a3,
1480 Object a4, Object a5)
1481 { return makeArray(a0, a1, a2, a3, a4, a5); }
1482 private static Object[] array(Object a0, Object a1, Object a2, Object a3,
1483 Object a4, Object a5, Object a6)
1484 { return makeArray(a0, a1, a2, a3, a4, a5, a6); }
1485 private static Object[] array(Object a0, Object a1, Object a2, Object a3,
1486 Object a4, Object a5, Object a6, Object a7)
1487 { return makeArray(a0, a1, a2, a3, a4, a5, a6, a7); }
1488 private static Object[] array(Object a0, Object a1, Object a2, Object a3,
1489 Object a4, Object a5, Object a6, Object a7,
1490 Object a8)
1491 { return makeArray(a0, a1, a2, a3, a4, a5, a6, a7, a8); }
1492 private static Object[] array(Object a0, Object a1, Object a2, Object a3,
1493 Object a4, Object a5, Object a6, Object a7,
1494 Object a8, Object a9)
1495 { return makeArray(a0, a1, a2, a3, a4, a5, a6, a7, a8, a9); }
1496
1497 private static final int ARRAYS_COUNT = 11;
1498 private static final @Stable MethodHandle[] ARRAYS = new MethodHandle[MAX_ARITY + 1];
1499
1500 // filling versions of the above:
1501 // using Integer len instead of int len and no varargs to avoid bootstrapping problems
1502 private static Object[] fillNewArray(Integer len, Object[] /*not ...*/ args) {
1503 Object[] a = new Object[len];
1504 fillWithArguments(a, 0, args);
1505 return a;
1506 }
1507 private static Object[] fillNewTypedArray(Object[] example, Integer len, Object[] /*not ...*/ args) {
1508 Object[] a = Arrays.copyOf(example, len);
1509 assert(a.getClass() != Object[].class);
1510 fillWithArguments(a, 0, args);
1511 return a;
1512 }
1513 private static void fillWithArguments(Object[] a, int pos, Object... args) {
1514 System.arraycopy(args, 0, a, pos, args.length);
1515 }
1516 // using Integer pos instead of int pos to avoid bootstrapping problems
1517 private static Object[] fillArray(Integer pos, Object[] a, Object a0)
1518 { fillWithArguments(a, pos, a0); return a; }
1519 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1)
1520 { fillWithArguments(a, pos, a0, a1); return a; }
1521 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2)
1522 { fillWithArguments(a, pos, a0, a1, a2); return a; }
1523 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3)
1524 { fillWithArguments(a, pos, a0, a1, a2, a3); return a; }
1525 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3,
1526 Object a4)
1527 { fillWithArguments(a, pos, a0, a1, a2, a3, a4); return a; }
1528 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3,
1529 Object a4, Object a5)
1530 { fillWithArguments(a, pos, a0, a1, a2, a3, a4, a5); return a; }
1531 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3,
1532 Object a4, Object a5, Object a6)
1533 { fillWithArguments(a, pos, a0, a1, a2, a3, a4, a5, a6); return a; }
1534 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3,
1535 Object a4, Object a5, Object a6, Object a7)
1536 { fillWithArguments(a, pos, a0, a1, a2, a3, a4, a5, a6, a7); return a; }
1537 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3,
1538 Object a4, Object a5, Object a6, Object a7,
1539 Object a8)
1540 { fillWithArguments(a, pos, a0, a1, a2, a3, a4, a5, a6, a7, a8); return a; }
1541 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3,
1542 Object a4, Object a5, Object a6, Object a7,
1543 Object a8, Object a9)
1544 { fillWithArguments(a, pos, a0, a1, a2, a3, a4, a5, a6, a7, a8, a9); return a; }
1545
1546 private static final int FILL_ARRAYS_COUNT = 11; // current number of fillArray methods
1547 private static final @Stable MethodHandle[] FILL_ARRAYS = new MethodHandle[FILL_ARRAYS_COUNT];
1548
1549 private static MethodHandle getFillArray(int count) {
1550 assert (count > 0 && count < FILL_ARRAYS_COUNT);
1551 MethodHandle mh = FILL_ARRAYS[count];
1552 if (mh != null) {
1553 return mh;
1554 }
1555 mh = findCollector("fillArray", count, Object[].class, Integer.class, Object[].class);
1556 FILL_ARRAYS[count] = mh;
1557 return mh;
1558 }
1559
1560 private static Object copyAsPrimitiveArray(Wrapper w, Object... boxes) {
1561 Object a = w.makeArray(boxes.length);
1562 w.copyArrayUnboxing(boxes, 0, a, 0, boxes.length);
1563 return a;
1564 }
1565
1566 /** Return a method handle that takes the indicated number of Object
1567 * arguments and returns an Object array of them, as if for varargs.
1568 */
1569 static MethodHandle varargsArray(int nargs) {
1570 MethodHandle mh = ARRAYS[nargs];
1571 if (mh != null) {
1572 return mh;
1573 }
1574 if (nargs < ARRAYS_COUNT) {
1575 mh = findCollector("array", nargs, Object[].class);
1576 } else {
1577 mh = buildVarargsArray(getConstantHandle(MH_fillNewArray),
1578 getConstantHandle(MH_arrayIdentity), nargs);
1579 }
1580 assert(assertCorrectArity(mh, nargs));
1581 mh = makeIntrinsic(mh, Intrinsic.NEW_ARRAY);
1582 return ARRAYS[nargs] = mh;
1583 }
1584
1585 private static boolean assertCorrectArity(MethodHandle mh, int arity) {
1586 assert(mh.type().parameterCount() == arity) : "arity != "+arity+": "+mh;
1587 return true;
1588 }
1589
1590 // Array identity function (used as getConstantHandle(MH_arrayIdentity)).
1591 static <T> T[] identity(T[] x) {
1592 return x;
1593 }
1594
1595 private static MethodHandle buildVarargsArray(MethodHandle newArray, MethodHandle finisher, int nargs) {
1596 // Build up the result mh as a sequence of fills like this:
1597 // finisher(fill(fill(newArrayWA(23,x1..x10),10,x11..x20),20,x21..x23))
1598 // The various fill(_,10*I,___*[J]) are reusable.
1599 int leftLen = Math.min(nargs, LEFT_ARGS); // absorb some arguments immediately
1600 int rightLen = nargs - leftLen;
1601 MethodHandle leftCollector = newArray.bindTo(nargs);
1602 leftCollector = leftCollector.asCollector(Object[].class, leftLen);
1603 MethodHandle mh = finisher;
1604 if (rightLen > 0) {
1605 MethodHandle rightFiller = fillToRight(LEFT_ARGS + rightLen);
1606 if (mh.equals(getConstantHandle(MH_arrayIdentity)))
1607 mh = rightFiller;
1608 else
1609 mh = MethodHandles.collectArguments(mh, 0, rightFiller);
1610 }
1611 if (mh.equals(getConstantHandle(MH_arrayIdentity)))
1612 mh = leftCollector;
1613 else
1614 mh = MethodHandles.collectArguments(mh, 0, leftCollector);
1615 return mh;
1616 }
1617
1618 private static final int LEFT_ARGS = FILL_ARRAYS_COUNT - 1;
1619 private static final @Stable MethodHandle[] FILL_ARRAY_TO_RIGHT = new MethodHandle[MAX_ARITY + 1];
1620 /** fill_array_to_right(N).invoke(a, argL..arg[N-1])
1621 * fills a[L]..a[N-1] with corresponding arguments,
1622 * and then returns a. The value L is a global constant (LEFT_ARGS).
1623 */
1624 private static MethodHandle fillToRight(int nargs) {
1625 MethodHandle filler = FILL_ARRAY_TO_RIGHT[nargs];
1626 if (filler != null) return filler;
1627 filler = buildFiller(nargs);
1628 assert(assertCorrectArity(filler, nargs - LEFT_ARGS + 1));
1629 return FILL_ARRAY_TO_RIGHT[nargs] = filler;
1630 }
1631 private static MethodHandle buildFiller(int nargs) {
1632 if (nargs <= LEFT_ARGS)
1633 return getConstantHandle(MH_arrayIdentity); // no args to fill; return the array unchanged
1634 // we need room for both mh and a in mh.invoke(a, arg*[nargs])
1635 final int CHUNK = LEFT_ARGS;
1636 int rightLen = nargs % CHUNK;
1637 int midLen = nargs - rightLen;
1638 if (rightLen == 0) {
1639 midLen = nargs - (rightLen = CHUNK);
1640 if (FILL_ARRAY_TO_RIGHT[midLen] == null) {
1641 // build some precursors from left to right
1642 for (int j = LEFT_ARGS % CHUNK; j < midLen; j += CHUNK)
1643 if (j > LEFT_ARGS) fillToRight(j);
1644 }
1645 }
1646 if (midLen < LEFT_ARGS) rightLen = nargs - (midLen = LEFT_ARGS);
1647 assert(rightLen > 0);
1648 MethodHandle midFill = fillToRight(midLen); // recursive fill
1649 MethodHandle rightFill = getFillArray(rightLen).bindTo(midLen); // [midLen..nargs-1]
1650 assert(midFill.type().parameterCount() == 1 + midLen - LEFT_ARGS);
1651 assert(rightFill.type().parameterCount() == 1 + rightLen);
1652
1653 // Combine the two fills:
1654 // right(mid(a, x10..x19), x20..x23)
1655 // The final product will look like this:
1656 // right(mid(newArrayLeft(24, x0..x9), x10..x19), x20..x23)
1657 if (midLen == LEFT_ARGS)
1658 return rightFill;
1659 else
1660 return MethodHandles.collectArguments(rightFill, 0, midFill);
1661 }
1662
1663 static final int MAX_JVM_ARITY = 255; // limit imposed by the JVM
1664
1665 /** Return a method handle that takes the indicated number of
1666 * typed arguments and returns an array of them.
1667 * The type argument is the array type.
1668 */
1669 static MethodHandle varargsArray(Class<?> arrayType, int nargs) {
1670 Class<?> elemType = arrayType.getComponentType();
1671 if (elemType == null) throw new IllegalArgumentException("not an array: "+arrayType);
1672 // FIXME: Need more special casing and caching here.
1673 if (nargs >= MAX_JVM_ARITY/2 - 1) {
1674 int slots = nargs;
1675 final int MAX_ARRAY_SLOTS = MAX_JVM_ARITY - 1; // 1 for receiver MH
1676 if (slots <= MAX_ARRAY_SLOTS && elemType.isPrimitive())
1677 slots *= Wrapper.forPrimitiveType(elemType).stackSlots();
1678 if (slots > MAX_ARRAY_SLOTS)
1679 throw new IllegalArgumentException("too many arguments: "+arrayType.getSimpleName()+", length "+nargs);
1680 }
1681 if (elemType == Object.class)
1682 return varargsArray(nargs);
1683 // other cases: primitive arrays, subtypes of Object[]
1684 MethodHandle cache[] = Makers.TYPED_COLLECTORS.get(elemType);
1685 MethodHandle mh = nargs < cache.length ? cache[nargs] : null;
1686 if (mh != null) return mh;
1687 if (nargs == 0) {
1688 Object example = java.lang.reflect.Array.newInstance(arrayType.getComponentType(), 0);
1689 mh = MethodHandles.constant(arrayType, example);
1690 } else if (elemType.isPrimitive()) {
1691 MethodHandle builder = getConstantHandle(MH_fillNewArray);
1692 MethodHandle producer = buildArrayProducer(arrayType);
1693 mh = buildVarargsArray(builder, producer, nargs);
1694 } else {
1695 Class<? extends Object[]> objArrayType = arrayType.asSubclass(Object[].class);
1696 Object[] example = Arrays.copyOf(NO_ARGS_ARRAY, 0, objArrayType);
1697 MethodHandle builder = getConstantHandle(MH_fillNewTypedArray).bindTo(example);
1698 MethodHandle producer = getConstantHandle(MH_arrayIdentity); // must be weakly typed
1699 mh = buildVarargsArray(builder, producer, nargs);
1700 }
1701 mh = mh.asType(MethodType.methodType(arrayType, Collections.<Class<?>>nCopies(nargs, elemType)));
1702 mh = makeIntrinsic(mh, Intrinsic.NEW_ARRAY);
1703 assert(assertCorrectArity(mh, nargs));
1704 if (nargs < cache.length)
1705 cache[nargs] = mh;
1706 return mh;
1707 }
1708
1709 private static MethodHandle buildArrayProducer(Class<?> arrayType) {
1710 Class<?> elemType = arrayType.getComponentType();
1711 assert(elemType.isPrimitive());
1712 return getConstantHandle(MH_copyAsPrimitiveArray).bindTo(Wrapper.forPrimitiveType(elemType));
1713 }
1714
1715 /*non-public*/ static void assertSame(Object mh1, Object mh2) {
1716 if (mh1 != mh2) {
1717 String msg = String.format("mh1 != mh2: mh1 = %s (form: %s); mh2 = %s (form: %s)",
1718 mh1, ((MethodHandle)mh1).form,
1719 mh2, ((MethodHandle)mh2).form);
1720 throw newInternalError(msg);
1721 }
1722 }
1723
1724 // Local constant functions:
1725
1726 /* non-public */
1727 static final byte NF_checkSpreadArgument = 0,
1728 NF_guardWithCatch = 1,
1729 NF_throwException = 2,
1730 NF_tryFinally = 3,
1731 NF_loop = 4,
1732 NF_profileBoolean = 5,
1733 NF_LIMIT = 6;
1734
1735 private static final @Stable NamedFunction[] NFS = new NamedFunction[NF_LIMIT];
1736
1737 static NamedFunction getFunction(byte func) {
1738 NamedFunction nf = NFS[func];
1739 if (nf != null) {
1740 return nf;
1741 }
1742 return NFS[func] = createFunction(func);
1743 }
1744
1745 private static NamedFunction createFunction(byte func) {
1746 try {
1747 switch (func) {
1748 case NF_checkSpreadArgument:
1749 return new NamedFunction(MethodHandleImpl.class
1750 .getDeclaredMethod("checkSpreadArgument", Object.class, int.class));
1751 case NF_guardWithCatch:
1752 return new NamedFunction(MethodHandleImpl.class
1753 .getDeclaredMethod("guardWithCatch", MethodHandle.class, Class.class,
1754 MethodHandle.class, Object[].class));
1755 case NF_tryFinally:
1756 return new NamedFunction(MethodHandleImpl.class
1757 .getDeclaredMethod("tryFinally", MethodHandle.class, MethodHandle.class, Object[].class));
1758 case NF_loop:
1759 return new NamedFunction(MethodHandleImpl.class
1760 .getDeclaredMethod("loop", BasicType[].class, LoopClauses.class, Object[].class));
1761 case NF_throwException:
1762 return new NamedFunction(MethodHandleImpl.class
1763 .getDeclaredMethod("throwException", Throwable.class));
1764 case NF_profileBoolean:
1765 return new NamedFunction(MethodHandleImpl.class
1766 .getDeclaredMethod("profileBoolean", boolean.class, int[].class));
1767 default:
1768 throw new InternalError("Undefined function: " + func);
1769 }
1770 } catch (ReflectiveOperationException ex) {
1771 throw newInternalError(ex);
1772 }
1773 }
1774
1775 static {
1776 SharedSecrets.setJavaLangInvokeAccess(new JavaLangInvokeAccess() {
1777 @Override
1778 public Object newMemberName() {
1779 return new MemberName();
1780 }
1781
1782 @Override
1783 public String getName(Object mname) {
1784 MemberName memberName = (MemberName)mname;
1785 return memberName.getName();
1786 }
1787
1788 @Override
1789 public MethodType getMethodType(Object mname) {
1790 MemberName memberName = (MemberName)mname;
1791 return memberName.getMethodType();
1792 }
1793
1794 @Override
1795 public String getMethodDescriptor(Object mname) {
1796 MemberName memberName = (MemberName)mname;
1797 return memberName.getMethodDescriptor();
1798 }
1799
1800 @Override
1801 public boolean isNative(Object mname) {
1802 MemberName memberName = (MemberName)mname;
1803 return memberName.isNative();
1804 }
1805
1806 @Override
1807 public byte[] generateDirectMethodHandleHolderClassBytes(
1808 String className, MethodType[] methodTypes, int[] types) {
1809 return GenerateJLIClassesHelper
1810 .generateDirectMethodHandleHolderClassBytes(
1811 className, methodTypes, types);
1812 }
1813
1814 @Override
1815 public byte[] generateDelegatingMethodHandleHolderClassBytes(
1816 String className, MethodType[] methodTypes) {
1817 return GenerateJLIClassesHelper
1818 .generateDelegatingMethodHandleHolderClassBytes(
1819 className, methodTypes);
1820 }
1821
1822 @Override
1823 public Map.Entry<String, byte[]> generateConcreteBMHClassBytes(
1824 final String types) {
1825 return GenerateJLIClassesHelper
1826 .generateConcreteBMHClassBytes(types);
1827 }
1828
1829 @Override
1830 public byte[] generateBasicFormsClassBytes(final String className) {
1831 return GenerateJLIClassesHelper
1832 .generateBasicFormsClassBytes(className);
1833 }
1834
1835 @Override
1836 public byte[] generateInvokersHolderClassBytes(final String className,
1837 MethodType[] methodTypes) {
1838 return GenerateJLIClassesHelper
1839 .generateInvokersHolderClassBytes(className, methodTypes);
1840 }
1841 });
1842 }
1843
1844 /** Result unboxing: ValueConversions.unbox() OR ValueConversions.identity() OR ValueConversions.ignore(). */
1845 private static MethodHandle unboxResultHandle(Class<?> returnType) {
1846 if (returnType.isPrimitive()) {
1847 if (returnType == void.class) {
1848 return ValueConversions.ignore();
1849 } else {
1850 Wrapper w = Wrapper.forPrimitiveType(returnType);
1851 return ValueConversions.unboxExact(w);
1852 }
1853 } else {
1854 return MethodHandles.identity(Object.class);
1855 }
1856 }
1857
1858 /**
1859 * Assembles a loop method handle from the given handles and type information.
1860 *
1861 * @param tloop the return type of the loop.
1862 * @param targs types of the arguments to be passed to the loop.
1863 * @param init sanitized array of initializers for loop-local variables.
1864 * @param step sanitited array of loop bodies.
1865 * @param pred sanitized array of predicates.
1866 * @param fini sanitized array of loop finalizers.
1867 *
1868 * @return a handle that, when invoked, will execute the loop.
1869 */
1870 static MethodHandle makeLoop(Class<?> tloop, List<Class<?>> targs, List<MethodHandle> init, List<MethodHandle> step,
1871 List<MethodHandle> pred, List<MethodHandle> fini) {
1872 MethodType type = MethodType.methodType(tloop, targs);
1873 BasicType[] initClauseTypes =
1874 init.stream().map(h -> h.type().returnType()).map(BasicType::basicType).toArray(BasicType[]::new);
1875 LambdaForm form = makeLoopForm(type.basicType(), initClauseTypes);
1876
1877 // Prepare auxiliary method handles used during LambdaForm interpretation.
1878 // Box arguments and wrap them into Object[]: ValueConversions.array().
1879 MethodType varargsType = type.changeReturnType(Object[].class);
1880 MethodHandle collectArgs = varargsArray(type.parameterCount()).asType(varargsType);
1881 MethodHandle unboxResult = unboxResultHandle(tloop);
1882
1883 LoopClauses clauseData =
1884 new LoopClauses(new MethodHandle[][]{toArray(init), toArray(step), toArray(pred), toArray(fini)});
1885 BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_LLL();
1886 BoundMethodHandle mh;
1887 try {
1888 mh = (BoundMethodHandle) data.constructor().invokeBasic(type, form, (Object) clauseData,
1889 (Object) collectArgs, (Object) unboxResult);
1890 } catch (Throwable ex) {
1891 throw uncaughtException(ex);
1892 }
1893 assert(mh.type() == type);
1894 return mh;
1895 }
1896
1897 private static MethodHandle[] toArray(List<MethodHandle> l) {
1898 return l.toArray(new MethodHandle[0]);
1899 }
1900
1901 /**
1902 * Loops introduce some complexity as they can have additional local state. Hence, LambdaForms for loops are
1903 * generated from a template. The LambdaForm template shape for the loop combinator is as follows (assuming one
1904 * reference parameter passed in {@code a1}, and a reference return type, with the return value represented by
1905 * {@code t12}):
1906 * <blockquote><pre>{@code
1907 * loop=Lambda(a0:L,a1:L)=>{
1908 * t2:L=BoundMethodHandle$Species_L3.argL0(a0:L); // LoopClauses holding init, step, pred, fini handles
1909 * t3:L=BoundMethodHandle$Species_L3.argL1(a0:L); // helper handle to box the arguments into an Object[]
1910 * t4:L=BoundMethodHandle$Species_L3.argL2(a0:L); // helper handle to unbox the result
1911 * t5:L=MethodHandle.invokeBasic(t3:L,a1:L); // box the arguments into an Object[]
1912 * t6:L=MethodHandleImpl.loop(null,t2:L,t3:L); // call the loop executor
1913 * t7:L=MethodHandle.invokeBasic(t4:L,t6:L);t7:L} // unbox the result; return the result
1914 * }</pre></blockquote>
1915 * <p>
1916 * {@code argL0} is a LoopClauses instance holding, in a 2-dimensional array, the init, step, pred, and fini method
1917 * handles. {@code argL1} and {@code argL2} are auxiliary method handles: {@code argL1} boxes arguments and wraps
1918 * them into {@code Object[]} ({@code ValueConversions.array()}), and {@code argL2} unboxes the result if necessary
1919 * ({@code ValueConversions.unbox()}).
1920 * <p>
1921 * Having {@code t3} and {@code t4} passed in via a BMH and not hardcoded in the lambda form allows to share lambda
1922 * forms among loop combinators with the same basic type.
1923 * <p>
1924 * The above template is instantiated by using the {@link LambdaFormEditor} to replace the {@code null} argument to
1925 * the {@code loop} invocation with the {@code BasicType} array describing the loop clause types. This argument is
1926 * ignored in the loop invoker, but will be extracted and used in {@linkplain InvokerBytecodeGenerator#emitLoop(int)
1927 * bytecode generation}.
1928 */
1929 private static LambdaForm makeLoopForm(MethodType basicType, BasicType[] localVarTypes) {
1930 MethodType lambdaType = basicType.invokerType();
1931
1932 final int THIS_MH = 0; // the BMH_LLL
1933 final int ARG_BASE = 1; // start of incoming arguments
1934 final int ARG_LIMIT = ARG_BASE + basicType.parameterCount();
1935
1936 int nameCursor = ARG_LIMIT;
1937 final int GET_CLAUSE_DATA = nameCursor++;
1938 final int GET_COLLECT_ARGS = nameCursor++;
1939 final int GET_UNBOX_RESULT = nameCursor++;
1940 final int BOXED_ARGS = nameCursor++;
1941 final int LOOP = nameCursor++;
1942 final int UNBOX_RESULT = nameCursor++;
1943
1944 LambdaForm lform = basicType.form().cachedLambdaForm(MethodTypeForm.LF_LOOP);
1945 if (lform == null) {
1946 Name[] names = arguments(nameCursor - ARG_LIMIT, lambdaType);
1947
1948 BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_LLL();
1949 names[THIS_MH] = names[THIS_MH].withConstraint(data);
1950 names[GET_CLAUSE_DATA] = new Name(data.getterFunction(0), names[THIS_MH]);
1951 names[GET_COLLECT_ARGS] = new Name(data.getterFunction(1), names[THIS_MH]);
1952 names[GET_UNBOX_RESULT] = new Name(data.getterFunction(2), names[THIS_MH]);
1953
1954 // t_{i}:L=MethodHandle.invokeBasic(collectArgs:L,a1:L,...);
1955 MethodType collectArgsType = basicType.changeReturnType(Object.class);
1956 MethodHandle invokeBasic = MethodHandles.basicInvoker(collectArgsType);
1957 Object[] args = new Object[invokeBasic.type().parameterCount()];
1958 args[0] = names[GET_COLLECT_ARGS];
1959 System.arraycopy(names, ARG_BASE, args, 1, ARG_LIMIT - ARG_BASE);
1960 names[BOXED_ARGS] = new Name(new NamedFunction(invokeBasic, Intrinsic.LOOP), args);
1961
1962 // t_{i+1}:L=MethodHandleImpl.loop(localTypes:L,clauses:L,t_{i}:L);
1963 Object[] lArgs =
1964 new Object[]{null, // placeholder for BasicType[] localTypes - will be added by LambdaFormEditor
1965 names[GET_CLAUSE_DATA], names[BOXED_ARGS]};
1966 names[LOOP] = new Name(getFunction(NF_loop), lArgs);
1967
1968 // t_{i+2}:I=MethodHandle.invokeBasic(unbox:L,t_{i+1}:L);
1969 MethodHandle invokeBasicUnbox = MethodHandles.basicInvoker(MethodType.methodType(basicType.rtype(), Object.class));
1970 Object[] unboxArgs = new Object[]{names[GET_UNBOX_RESULT], names[LOOP]};
1971 names[UNBOX_RESULT] = new Name(invokeBasicUnbox, unboxArgs);
1972
1973 lform = basicType.form().setCachedLambdaForm(MethodTypeForm.LF_LOOP,
1974 new LambdaForm(lambdaType.parameterCount(), names, Kind.LOOP));
1975 }
1976
1977 // BOXED_ARGS is the index into the names array where the loop idiom starts
1978 return lform.editor().noteLoopLocalTypesForm(BOXED_ARGS, localVarTypes);
1979 }
1980
1981 static class LoopClauses {
1982 @Stable final MethodHandle[][] clauses;
1983 LoopClauses(MethodHandle[][] clauses) {
1984 assert clauses.length == 4;
1985 this.clauses = clauses;
1986 }
1987 @Override
1988 public String toString() {
1989 StringBuffer sb = new StringBuffer("LoopClauses -- ");
1990 for (int i = 0; i < 4; ++i) {
1991 if (i > 0) {
1992 sb.append(" ");
1993 }
1994 sb.append('<').append(i).append(">: ");
1995 MethodHandle[] hs = clauses[i];
1996 for (int j = 0; j < hs.length; ++j) {
1997 if (j > 0) {
1998 sb.append(" ");
1999 }
2000 sb.append('*').append(j).append(": ").append(hs[j]).append('\n');
2001 }
2002 }
2003 sb.append(" --\n");
2004 return sb.toString();
2005 }
2006 }
2007
2008 /**
2009 * Intrinsified during LambdaForm compilation
2010 * (see {@link InvokerBytecodeGenerator#emitLoop(int)}).
2011 */
2012 @LambdaForm.Hidden
2013 static Object loop(BasicType[] localTypes, LoopClauses clauseData, Object... av) throws Throwable {
2014 final MethodHandle[] init = clauseData.clauses[0];
2015 final MethodHandle[] step = clauseData.clauses[1];
2016 final MethodHandle[] pred = clauseData.clauses[2];
2017 final MethodHandle[] fini = clauseData.clauses[3];
2018 int varSize = (int) Stream.of(init).filter(h -> h.type().returnType() != void.class).count();
2019 int nArgs = init[0].type().parameterCount();
2020 Object[] varsAndArgs = new Object[varSize + nArgs];
2021 for (int i = 0, v = 0; i < init.length; ++i) {
2022 MethodHandle ih = init[i];
2023 if (ih.type().returnType() == void.class) {
2024 ih.invokeWithArguments(av);
2025 } else {
2026 varsAndArgs[v++] = ih.invokeWithArguments(av);
2027 }
2028 }
2029 System.arraycopy(av, 0, varsAndArgs, varSize, nArgs);
2030 final int nSteps = step.length;
2031 for (; ; ) {
2032 for (int i = 0, v = 0; i < nSteps; ++i) {
2033 MethodHandle p = pred[i];
2034 MethodHandle s = step[i];
2035 MethodHandle f = fini[i];
2036 if (s.type().returnType() == void.class) {
2037 s.invokeWithArguments(varsAndArgs);
2038 } else {
2039 varsAndArgs[v++] = s.invokeWithArguments(varsAndArgs);
2040 }
2041 if (!(boolean) p.invokeWithArguments(varsAndArgs)) {
2042 return f.invokeWithArguments(varsAndArgs);
2043 }
2044 }
2045 }
2046 }
2047
2048 /**
2049 * This method is bound as the predicate in {@linkplain MethodHandles#countedLoop(MethodHandle, MethodHandle,
2050 * MethodHandle) counting loops}.
2051 *
2052 * @param limit the upper bound of the parameter, statically bound at loop creation time.
2053 * @param counter the counter parameter, passed in during loop execution.
2054 *
2055 * @return whether the counter has reached the limit.
2056 */
2057 static boolean countedLoopPredicate(int limit, int counter) {
2058 return counter < limit;
2059 }
2060
2061 /**
2062 * This method is bound as the step function in {@linkplain MethodHandles#countedLoop(MethodHandle, MethodHandle,
2063 * MethodHandle) counting loops} to increment the counter.
2064 *
2065 * @param limit the upper bound of the loop counter (ignored).
2066 * @param counter the loop counter.
2067 *
2068 * @return the loop counter incremented by 1.
2069 */
2070 static int countedLoopStep(int limit, int counter) {
2071 return counter + 1;
2072 }
2073
2074 /**
2075 * This is bound to initialize the loop-local iterator in {@linkplain MethodHandles#iteratedLoop iterating loops}.
2076 *
2077 * @param it the {@link Iterable} over which the loop iterates.
2078 *
2079 * @return an {@link Iterator} over the argument's elements.
2080 */
2081 static Iterator<?> initIterator(Iterable<?> it) {
2082 return it.iterator();
2083 }
2084
2085 /**
2086 * This method is bound as the predicate in {@linkplain MethodHandles#iteratedLoop iterating loops}.
2087 *
2088 * @param it the iterator to be checked.
2089 *
2090 * @return {@code true} iff there are more elements to iterate over.
2091 */
2092 static boolean iteratePredicate(Iterator<?> it) {
2093 return it.hasNext();
2094 }
2095
2096 /**
2097 * This method is bound as the step for retrieving the current value from the iterator in {@linkplain
2098 * MethodHandles#iteratedLoop iterating loops}.
2099 *
2100 * @param it the iterator.
2101 *
2102 * @return the next element from the iterator.
2103 */
2104 static Object iterateNext(Iterator<?> it) {
2105 return it.next();
2106 }
2107
2108 /**
2109 * Makes a {@code try-finally} handle that conforms to the type constraints.
2110 *
2111 * @param target the target to execute in a {@code try-finally} block.
2112 * @param cleanup the cleanup to execute in the {@code finally} block.
2113 * @param rtype the result type of the entire construct.
2114 * @param argTypes the types of the arguments.
2115 *
2116 * @return a handle on the constructed {@code try-finally} block.
2117 */
2118 static MethodHandle makeTryFinally(MethodHandle target, MethodHandle cleanup, Class<?> rtype, List<Class<?>> argTypes) {
2119 MethodType type = MethodType.methodType(rtype, argTypes);
2120 LambdaForm form = makeTryFinallyForm(type.basicType());
2121
2122 // Prepare auxiliary method handles used during LambdaForm interpretation.
2123 // Box arguments and wrap them into Object[]: ValueConversions.array().
2124 MethodType varargsType = type.changeReturnType(Object[].class);
2125 MethodHandle collectArgs = varargsArray(type.parameterCount()).asType(varargsType);
2126 MethodHandle unboxResult = unboxResultHandle(rtype);
2127
2128 BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_LLLL();
2129 BoundMethodHandle mh;
2130 try {
2131 mh = (BoundMethodHandle) data.constructor().invokeBasic(type, form, (Object) target, (Object) cleanup,
2132 (Object) collectArgs, (Object) unboxResult);
2133 } catch (Throwable ex) {
2134 throw uncaughtException(ex);
2135 }
2136 assert(mh.type() == type);
2137 return mh;
2138 }
2139
2140 /**
2141 * The LambdaForm shape for the tryFinally combinator is as follows (assuming one reference parameter passed in
2142 * {@code a1}, and a reference return type, with the return value represented by {@code t8}):
2143 * <blockquote><pre>{@code
2144 * tryFinally=Lambda(a0:L,a1:L)=>{
2145 * t2:L=BoundMethodHandle$Species_LLLL.argL0(a0:L); // target method handle
2146 * t3:L=BoundMethodHandle$Species_LLLL.argL1(a0:L); // cleanup method handle
2147 * t4:L=BoundMethodHandle$Species_LLLL.argL2(a0:L); // helper handle to box the arguments into an Object[]
2148 * t5:L=BoundMethodHandle$Species_LLLL.argL3(a0:L); // helper handle to unbox the result
2149 * t6:L=MethodHandle.invokeBasic(t4:L,a1:L); // box the arguments into an Object[]
2150 * t7:L=MethodHandleImpl.tryFinally(t2:L,t3:L,t6:L); // call the tryFinally executor
2151 * t8:L=MethodHandle.invokeBasic(t5:L,t7:L);t8:L} // unbox the result; return the result
2152 * }</pre></blockquote>
2153 * <p>
2154 * {@code argL0} and {@code argL1} are the target and cleanup method handles.
2155 * {@code argL2} and {@code argL3} are auxiliary method handles: {@code argL2} boxes arguments and wraps them into
2156 * {@code Object[]} ({@code ValueConversions.array()}), and {@code argL3} unboxes the result if necessary
2157 * ({@code ValueConversions.unbox()}).
2158 * <p>
2159 * Having {@code t4} and {@code t5} passed in via a BMH and not hardcoded in the lambda form allows to share lambda
2160 * forms among tryFinally combinators with the same basic type.
2161 */
2162 private static LambdaForm makeTryFinallyForm(MethodType basicType) {
2163 MethodType lambdaType = basicType.invokerType();
2164
2165 LambdaForm lform = basicType.form().cachedLambdaForm(MethodTypeForm.LF_TF);
2166 if (lform != null) {
2167 return lform;
2168 }
2169 final int THIS_MH = 0; // the BMH_LLLL
2170 final int ARG_BASE = 1; // start of incoming arguments
2171 final int ARG_LIMIT = ARG_BASE + basicType.parameterCount();
2172
2173 int nameCursor = ARG_LIMIT;
2174 final int GET_TARGET = nameCursor++;
2175 final int GET_CLEANUP = nameCursor++;
2176 final int GET_COLLECT_ARGS = nameCursor++;
2177 final int GET_UNBOX_RESULT = nameCursor++;
2178 final int BOXED_ARGS = nameCursor++;
2179 final int TRY_FINALLY = nameCursor++;
2180 final int UNBOX_RESULT = nameCursor++;
2181
2182 Name[] names = arguments(nameCursor - ARG_LIMIT, lambdaType);
2183
2184 BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_LLLL();
2185 names[THIS_MH] = names[THIS_MH].withConstraint(data);
2186 names[GET_TARGET] = new Name(data.getterFunction(0), names[THIS_MH]);
2187 names[GET_CLEANUP] = new Name(data.getterFunction(1), names[THIS_MH]);
2188 names[GET_COLLECT_ARGS] = new Name(data.getterFunction(2), names[THIS_MH]);
2189 names[GET_UNBOX_RESULT] = new Name(data.getterFunction(3), names[THIS_MH]);
2190
2191 // t_{i}:L=MethodHandle.invokeBasic(collectArgs:L,a1:L,...);
2192 MethodType collectArgsType = basicType.changeReturnType(Object.class);
2193 MethodHandle invokeBasic = MethodHandles.basicInvoker(collectArgsType);
2194 Object[] args = new Object[invokeBasic.type().parameterCount()];
2195 args[0] = names[GET_COLLECT_ARGS];
2196 System.arraycopy(names, ARG_BASE, args, 1, ARG_LIMIT-ARG_BASE);
2197 names[BOXED_ARGS] = new Name(new NamedFunction(invokeBasic, Intrinsic.TRY_FINALLY), args);
2198
2199 // t_{i+1}:L=MethodHandleImpl.tryFinally(target:L,exType:L,catcher:L,t_{i}:L);
2200 Object[] tfArgs = new Object[] {names[GET_TARGET], names[GET_CLEANUP], names[BOXED_ARGS]};
2201 names[TRY_FINALLY] = new Name(getFunction(NF_tryFinally), tfArgs);
2202
2203 // t_{i+2}:I=MethodHandle.invokeBasic(unbox:L,t_{i+1}:L);
2204 MethodHandle invokeBasicUnbox = MethodHandles.basicInvoker(MethodType.methodType(basicType.rtype(), Object.class));
2205 Object[] unboxArgs = new Object[] {names[GET_UNBOX_RESULT], names[TRY_FINALLY]};
2206 names[UNBOX_RESULT] = new Name(invokeBasicUnbox, unboxArgs);
2207
2208 lform = new LambdaForm(lambdaType.parameterCount(), names, Kind.TRY_FINALLY);
2209
2210 return basicType.form().setCachedLambdaForm(MethodTypeForm.LF_TF, lform);
2211 }
2212
2213 /**
2214 * Intrinsified during LambdaForm compilation
2215 * (see {@link InvokerBytecodeGenerator#emitTryFinally emitTryFinally}).
2216 */
2217 @LambdaForm.Hidden
2218 static Object tryFinally(MethodHandle target, MethodHandle cleanup, Object... av) throws Throwable {
2219 Throwable t = null;
2220 Object r = null;
2221 try {
2222 r = target.invokeWithArguments(av);
2223 } catch (Throwable thrown) {
2224 t = thrown;
2225 throw t;
2226 } finally {
2227 Object[] args = target.type().returnType() == void.class ? prepend(av, t) : prepend(av, t, r);
2228 r = cleanup.invokeWithArguments(args);
2229 }
2230 return r;
2231 }
2232
2233 // Indexes into constant method handles:
2234 static final int
2235 MH_cast = 0,
2236 MH_selectAlternative = 1,
2237 MH_copyAsPrimitiveArray = 2,
2238 MH_fillNewTypedArray = 3,
2239 MH_fillNewArray = 4,
2240 MH_arrayIdentity = 5,
2241 MH_countedLoopPred = 6,
2242 MH_countedLoopStep = 7,
2243 MH_initIterator = 8,
2244 MH_iteratePred = 9,
2245 MH_iterateNext = 10,
2246 MH_Array_newInstance = 11,
2247 MH_LIMIT = 12;
2248
2249 static MethodHandle getConstantHandle(int idx) {
2250 MethodHandle handle = HANDLES[idx];
2251 if (handle != null) {
2252 return handle;
2253 }
2254 return setCachedHandle(idx, makeConstantHandle(idx));
2255 }
2256
2257 private static synchronized MethodHandle setCachedHandle(int idx, final MethodHandle method) {
2258 // Simulate a CAS, to avoid racy duplication of results.
2259 MethodHandle prev = HANDLES[idx];
2260 if (prev != null) {
2261 return prev;
2262 }
2263 HANDLES[idx] = method;
2264 return method;
2265 }
2266
2267 // Local constant method handles:
2268 private static final @Stable MethodHandle[] HANDLES = new MethodHandle[MH_LIMIT];
2269
2270 private static MethodHandle makeConstantHandle(int idx) {
2271 try {
2272 switch (idx) {
2273 case MH_cast:
2274 return IMPL_LOOKUP.findVirtual(Class.class, "cast",
2275 MethodType.methodType(Object.class, Object.class));
2276 case MH_copyAsPrimitiveArray:
2277 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "copyAsPrimitiveArray",
2278 MethodType.methodType(Object.class, Wrapper.class, Object[].class));
2279 case MH_arrayIdentity:
2280 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "identity",
2281 MethodType.methodType(Object[].class, Object[].class));
2282 case MH_fillNewArray:
2283 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "fillNewArray",
2284 MethodType.methodType(Object[].class, Integer.class, Object[].class));
2285 case MH_fillNewTypedArray:
2286 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "fillNewTypedArray",
2287 MethodType.methodType(Object[].class, Object[].class, Integer.class, Object[].class));
2288 case MH_selectAlternative:
2289 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "selectAlternative",
2290 MethodType.methodType(MethodHandle.class, boolean.class, MethodHandle.class, MethodHandle.class));
2291 case MH_countedLoopPred:
2292 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "countedLoopPredicate",
2293 MethodType.methodType(boolean.class, int.class, int.class));
2294 case MH_countedLoopStep:
2295 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "countedLoopStep",
2296 MethodType.methodType(int.class, int.class, int.class));
2297 case MH_initIterator:
2298 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "initIterator",
2299 MethodType.methodType(Iterator.class, Iterable.class));
2300 case MH_iteratePred:
2301 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "iteratePredicate",
2302 MethodType.methodType(boolean.class, Iterator.class));
2303 case MH_iterateNext:
2304 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "iterateNext",
2305 MethodType.methodType(Object.class, Iterator.class));
2306 case MH_Array_newInstance:
2307 return IMPL_LOOKUP.findStatic(Array.class, "newInstance",
2308 MethodType.methodType(Object.class, Class.class, int.class));
2309 }
2310 } catch (ReflectiveOperationException ex) {
2311 throw newInternalError(ex);
2312 }
2313 throw newInternalError("Unknown function index: " + idx);
2314 }
2315 }