1 /*
2 * Copyright (c) 2008, 2016, 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.org.objectweb.asm.AnnotationVisitor;
29 import jdk.internal.org.objectweb.asm.ClassWriter;
30 import jdk.internal.org.objectweb.asm.MethodVisitor;
31 import jdk.internal.reflect.CallerSensitive;
32 import jdk.internal.reflect.Reflection;
33 import jdk.internal.vm.annotation.ForceInline;
34 import jdk.internal.vm.annotation.Stable;
35 import sun.invoke.empty.Empty;
36 import sun.invoke.util.ValueConversions;
37 import sun.invoke.util.VerifyType;
38 import sun.invoke.util.Wrapper;
39
40 import java.lang.reflect.Array;
41 import java.security.AccessController;
42 import java.security.PrivilegedAction;
43 import java.util.Arrays;
44 import java.util.Collections;
45 import java.util.Iterator;
46 import java.util.List;
47 import java.util.function.Function;
48 import java.util.stream.Stream;
49
50 import static java.lang.invoke.LambdaForm.*;
51 import static java.lang.invoke.MethodHandleStatics.*;
52 import static java.lang.invoke.MethodHandles.Lookup.IMPL_LOOKUP;
53 import static jdk.internal.org.objectweb.asm.Opcodes.*;
54
55 /**
56 * Trusted implementation code for MethodHandle.
57 * @author jrose
58 */
59 /*non-public*/ abstract class MethodHandleImpl {
60 // Do not adjust this except for special platforms:
61 private static final int MAX_ARITY;
62 static {
63 final Object[] values = { 255 };
64 AccessController.doPrivileged(new PrivilegedAction<>() {
65 @Override
66 public Void run() {
67 values[0] = Integer.getInteger(MethodHandleImpl.class.getName()+".MAX_ARITY", 255);
68 return null;
69 }
70 });
71 MAX_ARITY = (Integer) values[0];
72 }
73
74 /// Factory methods to create method handles:
75
76 static MethodHandle makeArrayElementAccessor(Class<?> arrayClass, ArrayAccess access) {
77 if (arrayClass == Object[].class) {
78 return ArrayAccess.objectAccessor(access);
79 }
80 if (!arrayClass.isArray())
81 throw newIllegalArgumentException("not an array: "+arrayClass);
82 MethodHandle[] cache = ArrayAccessor.TYPED_ACCESSORS.get(arrayClass);
83 int cacheIndex = ArrayAccess.cacheIndex(access);
84 MethodHandle mh = cache[cacheIndex];
85 if (mh != null) return mh;
86 mh = ArrayAccessor.getAccessor(arrayClass, access);
87 MethodType correctType = ArrayAccessor.correctType(arrayClass, access);
88 if (mh.type() != correctType) {
89 assert(mh.type().parameterType(0) == Object[].class);
90 /* if access == SET */ assert(access != ArrayAccess.SET || mh.type().parameterType(2) == Object.class);
91 /* if access == GET */ assert(access != ArrayAccess.GET ||
92 (mh.type().returnType() == Object.class &&
93 correctType.parameterType(0).getComponentType() == correctType.returnType()));
94 // safe to view non-strictly, because element type follows from array type
95 mh = mh.viewAsType(correctType, false);
96 }
97 mh = makeIntrinsic(mh, ArrayAccess.intrinsic(access));
98 // Atomically update accessor cache.
99 synchronized(cache) {
100 if (cache[cacheIndex] == null) {
101 cache[cacheIndex] = mh;
102 } else {
103 // Throw away newly constructed accessor and use cached version.
104 mh = cache[cacheIndex];
105 }
106 }
107 return mh;
108 }
109
110 enum ArrayAccess {
111 GET, SET, LENGTH;
112
113 // As ArrayAccess and ArrayAccessor have a circular dependency, the ArrayAccess properties cannot be stored in
114 // final fields.
115
116 static String opName(ArrayAccess a) {
117 switch (a) {
118 case GET: return "getElement";
119 case SET: return "setElement";
120 case LENGTH: return "length";
121 }
122 throw unmatchedArrayAccess(a);
123 }
124
125 static MethodHandle objectAccessor(ArrayAccess a) {
126 switch (a) {
127 case GET: return ArrayAccessor.OBJECT_ARRAY_GETTER;
128 case SET: return ArrayAccessor.OBJECT_ARRAY_SETTER;
129 case LENGTH: return ArrayAccessor.OBJECT_ARRAY_LENGTH;
130 }
131 throw unmatchedArrayAccess(a);
132 }
133
134 static int cacheIndex(ArrayAccess a) {
135 switch (a) {
136 case GET: return ArrayAccessor.GETTER_INDEX;
137 case SET: return ArrayAccessor.SETTER_INDEX;
138 case LENGTH: return ArrayAccessor.LENGTH_INDEX;
139 }
140 throw unmatchedArrayAccess(a);
141 }
142
143 static Intrinsic intrinsic(ArrayAccess a) {
144 switch (a) {
145 case GET: return Intrinsic.ARRAY_LOAD;
146 case SET: return Intrinsic.ARRAY_STORE;
147 case LENGTH: return Intrinsic.ARRAY_LENGTH;
148 }
149 throw unmatchedArrayAccess(a);
150 }
151 }
152
153 static InternalError unmatchedArrayAccess(ArrayAccess a) {
154 return newInternalError("should not reach here (unmatched ArrayAccess: " + a + ")");
155 }
156
157 static final class ArrayAccessor {
158 /// Support for array element and length access
159 static final int GETTER_INDEX = 0, SETTER_INDEX = 1, LENGTH_INDEX = 2, INDEX_LIMIT = 3;
160 static final ClassValue<MethodHandle[]> TYPED_ACCESSORS
161 = new ClassValue<MethodHandle[]>() {
162 @Override
163 protected MethodHandle[] computeValue(Class<?> type) {
164 return new MethodHandle[INDEX_LIMIT];
165 }
166 };
167 static final MethodHandle OBJECT_ARRAY_GETTER, OBJECT_ARRAY_SETTER, OBJECT_ARRAY_LENGTH;
168 static {
169 MethodHandle[] cache = TYPED_ACCESSORS.get(Object[].class);
170 cache[GETTER_INDEX] = OBJECT_ARRAY_GETTER = makeIntrinsic(getAccessor(Object[].class, ArrayAccess.GET), Intrinsic.ARRAY_LOAD);
171 cache[SETTER_INDEX] = OBJECT_ARRAY_SETTER = makeIntrinsic(getAccessor(Object[].class, ArrayAccess.SET), Intrinsic.ARRAY_STORE);
172 cache[LENGTH_INDEX] = OBJECT_ARRAY_LENGTH = makeIntrinsic(getAccessor(Object[].class, ArrayAccess.LENGTH), Intrinsic.ARRAY_LENGTH);
173
174 assert(InvokerBytecodeGenerator.isStaticallyInvocable(ArrayAccessor.OBJECT_ARRAY_GETTER.internalMemberName()));
175 assert(InvokerBytecodeGenerator.isStaticallyInvocable(ArrayAccessor.OBJECT_ARRAY_SETTER.internalMemberName()));
176 assert(InvokerBytecodeGenerator.isStaticallyInvocable(ArrayAccessor.OBJECT_ARRAY_LENGTH.internalMemberName()));
177 }
178
179 static int getElementI(int[] a, int i) { return a[i]; }
180 static long getElementJ(long[] a, int i) { return a[i]; }
181 static float getElementF(float[] a, int i) { return a[i]; }
182 static double getElementD(double[] a, int i) { return a[i]; }
183 static boolean getElementZ(boolean[] a, int i) { return a[i]; }
184 static byte getElementB(byte[] a, int i) { return a[i]; }
185 static short getElementS(short[] a, int i) { return a[i]; }
186 static char getElementC(char[] a, int i) { return a[i]; }
187 static Object getElementL(Object[] a, int i) { return a[i]; }
188
189 static void setElementI(int[] a, int i, int x) { a[i] = x; }
190 static void setElementJ(long[] a, int i, long x) { a[i] = x; }
191 static void setElementF(float[] a, int i, float x) { a[i] = x; }
192 static void setElementD(double[] a, int i, double x) { a[i] = x; }
193 static void setElementZ(boolean[] a, int i, boolean x) { a[i] = x; }
194 static void setElementB(byte[] a, int i, byte x) { a[i] = x; }
195 static void setElementS(short[] a, int i, short x) { a[i] = x; }
196 static void setElementC(char[] a, int i, char x) { a[i] = x; }
197 static void setElementL(Object[] a, int i, Object x) { a[i] = x; }
198
199 static int lengthI(int[] a) { return a.length; }
200 static int lengthJ(long[] a) { return a.length; }
201 static int lengthF(float[] a) { return a.length; }
202 static int lengthD(double[] a) { return a.length; }
203 static int lengthZ(boolean[] a) { return a.length; }
204 static int lengthB(byte[] a) { return a.length; }
205 static int lengthS(short[] a) { return a.length; }
206 static int lengthC(char[] a) { return a.length; }
207 static int lengthL(Object[] a) { return a.length; }
208
209 static String name(Class<?> arrayClass, ArrayAccess access) {
210 Class<?> elemClass = arrayClass.getComponentType();
211 if (elemClass == null) throw newIllegalArgumentException("not an array", arrayClass);
212 return ArrayAccess.opName(access) + Wrapper.basicTypeChar(elemClass);
213 }
214 static MethodType type(Class<?> arrayClass, ArrayAccess access) {
215 Class<?> elemClass = arrayClass.getComponentType();
216 Class<?> arrayArgClass = arrayClass;
217 if (!elemClass.isPrimitive()) {
218 arrayArgClass = Object[].class;
219 elemClass = Object.class;
220 }
221 switch (access) {
222 case GET: return MethodType.methodType(elemClass, arrayArgClass, int.class);
223 case SET: return MethodType.methodType(void.class, arrayArgClass, int.class, elemClass);
224 case LENGTH: return MethodType.methodType(int.class, arrayArgClass);
225 }
226 throw unmatchedArrayAccess(access);
227 }
228 static MethodType correctType(Class<?> arrayClass, ArrayAccess access) {
229 Class<?> elemClass = arrayClass.getComponentType();
230 switch (access) {
231 case GET: return MethodType.methodType(elemClass, arrayClass, int.class);
232 case SET: return MethodType.methodType(void.class, arrayClass, int.class, elemClass);
233 case LENGTH: return MethodType.methodType(int.class, arrayClass);
234 }
235 throw unmatchedArrayAccess(access);
236 }
237 static MethodHandle getAccessor(Class<?> arrayClass, ArrayAccess access) {
238 String name = name(arrayClass, access);
239 MethodType type = type(arrayClass, access);
240 try {
241 return IMPL_LOOKUP.findStatic(ArrayAccessor.class, name, type);
242 } catch (ReflectiveOperationException ex) {
243 throw uncaughtException(ex);
244 }
245 }
246 }
247
248 /**
249 * Create a JVM-level adapter method handle to conform the given method
250 * handle to the similar newType, using only pairwise argument conversions.
251 * For each argument, convert incoming argument to the exact type needed.
252 * The argument conversions allowed are casting, boxing and unboxing,
253 * integral widening or narrowing, and floating point widening or narrowing.
254 * @param srcType required call type
255 * @param target original method handle
256 * @param strict if true, only asType conversions are allowed; if false, explicitCastArguments conversions allowed
257 * @param monobox if true, unboxing conversions are assumed to be exactly typed (Integer to int only, not long or double)
258 * @return an adapter to the original handle with the desired new type,
259 * or the original target if the types are already identical
260 * or null if the adaptation cannot be made
261 */
262 static MethodHandle makePairwiseConvert(MethodHandle target, MethodType srcType,
263 boolean strict, boolean monobox) {
264 MethodType dstType = target.type();
265 if (srcType == dstType)
266 return target;
267 return makePairwiseConvertByEditor(target, srcType, strict, monobox);
268 }
269
270 private static int countNonNull(Object[] array) {
271 int count = 0;
272 for (Object x : array) {
273 if (x != null) ++count;
274 }
275 return count;
276 }
277
278 static MethodHandle makePairwiseConvertByEditor(MethodHandle target, MethodType srcType,
279 boolean strict, boolean monobox) {
280 Object[] convSpecs = computeValueConversions(srcType, target.type(), strict, monobox);
281 int convCount = countNonNull(convSpecs);
282 if (convCount == 0)
283 return target.viewAsType(srcType, strict);
284 MethodType basicSrcType = srcType.basicType();
285 MethodType midType = target.type().basicType();
286 BoundMethodHandle mh = target.rebind();
287 // FIXME: Reduce number of bindings when there is more than one Class conversion.
288 // FIXME: Reduce number of bindings when there are repeated conversions.
289 for (int i = 0; i < convSpecs.length-1; i++) {
290 Object convSpec = convSpecs[i];
291 if (convSpec == null) continue;
292 MethodHandle fn;
293 if (convSpec instanceof Class) {
294 fn = getConstantHandle(MH_cast).bindTo(convSpec);
295 } else {
296 fn = (MethodHandle) convSpec;
297 }
298 Class<?> newType = basicSrcType.parameterType(i);
299 if (--convCount == 0)
300 midType = srcType;
301 else
302 midType = midType.changeParameterType(i, newType);
303 LambdaForm form2 = mh.editor().filterArgumentForm(1+i, BasicType.basicType(newType));
304 mh = mh.copyWithExtendL(midType, form2, fn);
305 mh = mh.rebind();
306 }
307 Object convSpec = convSpecs[convSpecs.length-1];
308 if (convSpec != null) {
309 MethodHandle fn;
310 if (convSpec instanceof Class) {
311 if (convSpec == void.class)
312 fn = null;
313 else
314 fn = getConstantHandle(MH_cast).bindTo(convSpec);
315 } else {
316 fn = (MethodHandle) convSpec;
317 }
318 Class<?> newType = basicSrcType.returnType();
319 assert(--convCount == 0);
320 midType = srcType;
321 if (fn != null) {
322 mh = mh.rebind(); // rebind if too complex
323 LambdaForm form2 = mh.editor().filterReturnForm(BasicType.basicType(newType), false);
324 mh = mh.copyWithExtendL(midType, form2, fn);
325 } else {
326 LambdaForm form2 = mh.editor().filterReturnForm(BasicType.basicType(newType), true);
327 mh = mh.copyWith(midType, form2);
328 }
329 }
330 assert(convCount == 0);
331 assert(mh.type().equals(srcType));
332 return mh;
333 }
334
335 static MethodHandle makePairwiseConvertIndirect(MethodHandle target, MethodType srcType,
336 boolean strict, boolean monobox) {
337 assert(target.type().parameterCount() == srcType.parameterCount());
338 // Calculate extra arguments (temporaries) required in the names array.
339 Object[] convSpecs = computeValueConversions(srcType, target.type(), strict, monobox);
340 final int INARG_COUNT = srcType.parameterCount();
341 int convCount = countNonNull(convSpecs);
342 boolean retConv = (convSpecs[INARG_COUNT] != null);
343 boolean retVoid = srcType.returnType() == void.class;
344 if (retConv && retVoid) {
345 convCount -= 1;
346 retConv = false;
347 }
348
349 final int IN_MH = 0;
350 final int INARG_BASE = 1;
351 final int INARG_LIMIT = INARG_BASE + INARG_COUNT;
352 final int NAME_LIMIT = INARG_LIMIT + convCount + 1;
353 final int RETURN_CONV = (!retConv ? -1 : NAME_LIMIT - 1);
354 final int OUT_CALL = (!retConv ? NAME_LIMIT : RETURN_CONV) - 1;
355 final int RESULT = (retVoid ? -1 : NAME_LIMIT - 1);
356
357 // Now build a LambdaForm.
358 MethodType lambdaType = srcType.basicType().invokerType();
359 Name[] names = arguments(NAME_LIMIT - INARG_LIMIT, lambdaType);
360
361 // Collect the arguments to the outgoing call, maybe with conversions:
362 final int OUTARG_BASE = 0; // target MH is Name.function, name Name.arguments[0]
363 Object[] outArgs = new Object[OUTARG_BASE + INARG_COUNT];
364
365 int nameCursor = INARG_LIMIT;
366 for (int i = 0; i < INARG_COUNT; i++) {
367 Object convSpec = convSpecs[i];
368 if (convSpec == null) {
369 // do nothing: difference is trivial
370 outArgs[OUTARG_BASE + i] = names[INARG_BASE + i];
371 continue;
372 }
373
374 Name conv;
375 if (convSpec instanceof Class) {
376 Class<?> convClass = (Class<?>) convSpec;
377 conv = new Name(getConstantHandle(MH_cast), convClass, names[INARG_BASE + i]);
378 } else {
379 MethodHandle fn = (MethodHandle) convSpec;
380 conv = new Name(fn, names[INARG_BASE + i]);
381 }
382 assert(names[nameCursor] == null);
383 names[nameCursor++] = conv;
384 assert(outArgs[OUTARG_BASE + i] == null);
385 outArgs[OUTARG_BASE + i] = conv;
386 }
387
388 // Build argument array for the call.
389 assert(nameCursor == OUT_CALL);
390 names[OUT_CALL] = new Name(target, outArgs);
391
392 Object convSpec = convSpecs[INARG_COUNT];
393 if (!retConv) {
394 assert(OUT_CALL == names.length-1);
395 } else {
396 Name conv;
397 if (convSpec == void.class) {
398 conv = new Name(LambdaForm.constantZero(BasicType.basicType(srcType.returnType())));
399 } else if (convSpec instanceof Class) {
400 Class<?> convClass = (Class<?>) convSpec;
401 conv = new Name(getConstantHandle(MH_cast), convClass, names[OUT_CALL]);
402 } else {
403 MethodHandle fn = (MethodHandle) convSpec;
404 if (fn.type().parameterCount() == 0)
405 conv = new Name(fn); // don't pass retval to void conversion
406 else
407 conv = new Name(fn, names[OUT_CALL]);
408 }
409 assert(names[RETURN_CONV] == null);
410 names[RETURN_CONV] = conv;
411 assert(RETURN_CONV == names.length-1);
412 }
413
414 LambdaForm form = new LambdaForm("convert", lambdaType.parameterCount(), names, RESULT);
415 return SimpleMethodHandle.make(srcType, form);
416 }
417
418 static Object[] computeValueConversions(MethodType srcType, MethodType dstType,
419 boolean strict, boolean monobox) {
420 final int INARG_COUNT = srcType.parameterCount();
421 Object[] convSpecs = new Object[INARG_COUNT+1];
422 for (int i = 0; i <= INARG_COUNT; i++) {
423 boolean isRet = (i == INARG_COUNT);
424 Class<?> src = isRet ? dstType.returnType() : srcType.parameterType(i);
425 Class<?> dst = isRet ? srcType.returnType() : dstType.parameterType(i);
426 if (!VerifyType.isNullConversion(src, dst, /*keepInterfaces=*/ strict)) {
427 convSpecs[i] = valueConversion(src, dst, strict, monobox);
428 }
429 }
430 return convSpecs;
431 }
432 static MethodHandle makePairwiseConvert(MethodHandle target, MethodType srcType,
433 boolean strict) {
434 return makePairwiseConvert(target, srcType, strict, /*monobox=*/ false);
435 }
436
437 /**
438 * Find a conversion function from the given source to the given destination.
439 * This conversion function will be used as a LF NamedFunction.
440 * Return a Class object if a simple cast is needed.
441 * Return void.class if void is involved.
442 */
443 static Object valueConversion(Class<?> src, Class<?> dst, boolean strict, boolean monobox) {
444 assert(!VerifyType.isNullConversion(src, dst, /*keepInterfaces=*/ strict)); // caller responsibility
445 if (dst == void.class)
446 return dst;
447 MethodHandle fn;
448 if (src.isPrimitive()) {
449 if (src == void.class) {
450 return void.class; // caller must recognize this specially
451 } else if (dst.isPrimitive()) {
452 // Examples: int->byte, byte->int, boolean->int (!strict)
453 fn = ValueConversions.convertPrimitive(src, dst);
454 } else {
455 // Examples: int->Integer, boolean->Object, float->Number
456 Wrapper wsrc = Wrapper.forPrimitiveType(src);
457 fn = ValueConversions.boxExact(wsrc);
458 assert(fn.type().parameterType(0) == wsrc.primitiveType());
459 assert(fn.type().returnType() == wsrc.wrapperType());
460 if (!VerifyType.isNullConversion(wsrc.wrapperType(), dst, strict)) {
461 // Corner case, such as int->Long, which will probably fail.
462 MethodType mt = MethodType.methodType(dst, src);
463 if (strict)
464 fn = fn.asType(mt);
465 else
466 fn = MethodHandleImpl.makePairwiseConvert(fn, mt, /*strict=*/ false);
467 }
468 }
469 } else if (dst.isPrimitive()) {
470 Wrapper wdst = Wrapper.forPrimitiveType(dst);
471 if (monobox || src == wdst.wrapperType()) {
472 // Use a strongly-typed unboxer, if possible.
473 fn = ValueConversions.unboxExact(wdst, strict);
474 } else {
475 // Examples: Object->int, Number->int, Comparable->int, Byte->int
476 // must include additional conversions
477 // src must be examined at runtime, to detect Byte, Character, etc.
478 fn = (strict
479 ? ValueConversions.unboxWiden(wdst)
480 : ValueConversions.unboxCast(wdst));
481 }
482 } else {
483 // Simple reference conversion.
484 // Note: Do not check for a class hierarchy relation
485 // between src and dst. In all cases a 'null' argument
486 // will pass the cast conversion.
487 return dst;
488 }
489 assert(fn.type().parameterCount() <= 1) : "pc"+Arrays.asList(src.getSimpleName(), dst.getSimpleName(), fn);
490 return fn;
491 }
492
493 static MethodHandle makeVarargsCollector(MethodHandle target, Class<?> arrayType) {
494 MethodType type = target.type();
495 int last = type.parameterCount() - 1;
496 if (type.parameterType(last) != arrayType)
497 target = target.asType(type.changeParameterType(last, arrayType));
498 target = target.asFixedArity(); // make sure this attribute is turned off
499 return new AsVarargsCollector(target, arrayType);
500 }
501
502 private static final class AsVarargsCollector extends DelegatingMethodHandle {
503 private final MethodHandle target;
504 private final Class<?> arrayType;
505 private @Stable MethodHandle asCollectorCache;
506
507 AsVarargsCollector(MethodHandle target, Class<?> arrayType) {
508 this(target.type(), target, arrayType);
509 }
510 AsVarargsCollector(MethodType type, MethodHandle target, Class<?> arrayType) {
511 super(type, target);
512 this.target = target;
513 this.arrayType = arrayType;
514 this.asCollectorCache = target.asCollector(arrayType, 0);
515 }
516
517 @Override
518 public boolean isVarargsCollector() {
519 return true;
520 }
521
522 @Override
523 protected MethodHandle getTarget() {
524 return target;
525 }
526
527 @Override
528 public MethodHandle asFixedArity() {
529 return target;
530 }
531
532 @Override
533 MethodHandle setVarargs(MemberName member) {
534 if (member.isVarargs()) return this;
535 return asFixedArity();
536 }
537
538 @Override
539 public MethodHandle asTypeUncached(MethodType newType) {
540 MethodType type = this.type();
541 int collectArg = type.parameterCount() - 1;
542 int newArity = newType.parameterCount();
543 if (newArity == collectArg+1 &&
544 type.parameterType(collectArg).isAssignableFrom(newType.parameterType(collectArg))) {
545 // if arity and trailing parameter are compatible, do normal thing
546 return asTypeCache = asFixedArity().asType(newType);
547 }
548 // check cache
549 MethodHandle acc = asCollectorCache;
550 if (acc != null && acc.type().parameterCount() == newArity)
551 return asTypeCache = acc.asType(newType);
552 // build and cache a collector
553 int arrayLength = newArity - collectArg;
554 MethodHandle collector;
555 try {
556 collector = asFixedArity().asCollector(arrayType, arrayLength);
557 assert(collector.type().parameterCount() == newArity) : "newArity="+newArity+" but collector="+collector;
558 } catch (IllegalArgumentException ex) {
559 throw new WrongMethodTypeException("cannot build collector", ex);
560 }
561 asCollectorCache = collector;
562 return asTypeCache = collector.asType(newType);
563 }
564
565 @Override
566 boolean viewAsTypeChecks(MethodType newType, boolean strict) {
567 super.viewAsTypeChecks(newType, true);
568 if (strict) return true;
569 // extra assertion for non-strict checks:
570 assert (type().lastParameterType().getComponentType()
571 .isAssignableFrom(
572 newType.lastParameterType().getComponentType()))
573 : Arrays.asList(this, newType);
574 return true;
575 }
576 }
577
578 /** Factory method: Spread selected argument. */
579 static MethodHandle makeSpreadArguments(MethodHandle target,
580 Class<?> spreadArgType, int spreadArgPos, int spreadArgCount) {
581 MethodType targetType = target.type();
582
583 for (int i = 0; i < spreadArgCount; i++) {
584 Class<?> arg = VerifyType.spreadArgElementType(spreadArgType, i);
585 if (arg == null) arg = Object.class;
586 targetType = targetType.changeParameterType(spreadArgPos + i, arg);
587 }
588 target = target.asType(targetType);
589
590 MethodType srcType = targetType
591 .replaceParameterTypes(spreadArgPos, spreadArgPos + spreadArgCount, spreadArgType);
592 // Now build a LambdaForm.
593 MethodType lambdaType = srcType.invokerType();
594 Name[] names = arguments(spreadArgCount + 2, lambdaType);
595 int nameCursor = lambdaType.parameterCount();
596 int[] indexes = new int[targetType.parameterCount()];
597
598 for (int i = 0, argIndex = 1; i < targetType.parameterCount() + 1; i++, argIndex++) {
599 Class<?> src = lambdaType.parameterType(i);
600 if (i == spreadArgPos) {
601 // Spread the array.
602 MethodHandle aload = MethodHandles.arrayElementGetter(spreadArgType);
603 Name array = names[argIndex];
604 names[nameCursor++] = new Name(NF_checkSpreadArgument, array, spreadArgCount);
605 for (int j = 0; j < spreadArgCount; i++, j++) {
606 indexes[i] = nameCursor;
607 names[nameCursor++] = new Name(aload, array, j);
608 }
609 } else if (i < indexes.length) {
610 indexes[i] = argIndex;
611 }
612 }
613 assert(nameCursor == names.length-1); // leave room for the final call
614
615 // Build argument array for the call.
616 Name[] targetArgs = new Name[targetType.parameterCount()];
617 for (int i = 0; i < targetType.parameterCount(); i++) {
618 int idx = indexes[i];
619 targetArgs[i] = names[idx];
620 }
621 names[names.length - 1] = new Name(target, (Object[]) targetArgs);
622
623 LambdaForm form = new LambdaForm("spread", lambdaType.parameterCount(), names);
624 return SimpleMethodHandle.make(srcType, form);
625 }
626
627 static void checkSpreadArgument(Object av, int n) {
628 if (av == null) {
629 if (n == 0) return;
630 } else if (av instanceof Object[]) {
631 int len = ((Object[])av).length;
632 if (len == n) return;
633 } else {
634 int len = java.lang.reflect.Array.getLength(av);
635 if (len == n) return;
636 }
637 // fall through to error:
638 throw newIllegalArgumentException("array is not of length "+n);
639 }
640
641 /** Factory method: Collect or filter selected argument(s). */
642 static MethodHandle makeCollectArguments(MethodHandle target,
643 MethodHandle collector, int collectArgPos, boolean retainOriginalArgs) {
644 MethodType targetType = target.type(); // (a..., c, [b...])=>r
645 MethodType collectorType = collector.type(); // (b...)=>c
646 int collectArgCount = collectorType.parameterCount();
647 Class<?> collectValType = collectorType.returnType();
648 int collectValCount = (collectValType == void.class ? 0 : 1);
649 MethodType srcType = targetType // (a..., [b...])=>r
650 .dropParameterTypes(collectArgPos, collectArgPos+collectValCount);
651 if (!retainOriginalArgs) { // (a..., b...)=>r
652 srcType = srcType.insertParameterTypes(collectArgPos, collectorType.parameterList());
653 }
654 // in arglist: [0: ...keep1 | cpos: collect... | cpos+cacount: keep2... ]
655 // out arglist: [0: ...keep1 | cpos: collectVal? | cpos+cvcount: keep2... ]
656 // out(retain): [0: ...keep1 | cpos: cV? coll... | cpos+cvc+cac: keep2... ]
657
658 // Now build a LambdaForm.
659 MethodType lambdaType = srcType.invokerType();
660 Name[] names = arguments(2, lambdaType);
661 final int collectNamePos = names.length - 2;
662 final int targetNamePos = names.length - 1;
663
664 Name[] collectorArgs = Arrays.copyOfRange(names, 1 + collectArgPos, 1 + collectArgPos + collectArgCount);
665 names[collectNamePos] = new Name(collector, (Object[]) collectorArgs);
666
667 // Build argument array for the target.
668 // Incoming LF args to copy are: [ (mh) headArgs collectArgs tailArgs ].
669 // Output argument array is [ headArgs (collectVal)? (collectArgs)? tailArgs ].
670 Name[] targetArgs = new Name[targetType.parameterCount()];
671 int inputArgPos = 1; // incoming LF args to copy to target
672 int targetArgPos = 0; // fill pointer for targetArgs
673 int chunk = collectArgPos; // |headArgs|
674 System.arraycopy(names, inputArgPos, targetArgs, targetArgPos, chunk);
675 inputArgPos += chunk;
676 targetArgPos += chunk;
677 if (collectValType != void.class) {
678 targetArgs[targetArgPos++] = names[collectNamePos];
679 }
680 chunk = collectArgCount;
681 if (retainOriginalArgs) {
682 System.arraycopy(names, inputArgPos, targetArgs, targetArgPos, chunk);
683 targetArgPos += chunk; // optionally pass on the collected chunk
684 }
685 inputArgPos += chunk;
686 chunk = targetArgs.length - targetArgPos; // all the rest
687 System.arraycopy(names, inputArgPos, targetArgs, targetArgPos, chunk);
688 assert(inputArgPos + chunk == collectNamePos); // use of rest of input args also
689 names[targetNamePos] = new Name(target, (Object[]) targetArgs);
690
691 LambdaForm form = new LambdaForm("collect", lambdaType.parameterCount(), names);
692 return SimpleMethodHandle.make(srcType, form);
693 }
694
695 @LambdaForm.Hidden
696 static
697 MethodHandle selectAlternative(boolean testResult, MethodHandle target, MethodHandle fallback) {
698 if (testResult) {
699 return target;
700 } else {
701 return fallback;
702 }
703 }
704
705 // Intrinsified by C2. Counters are used during parsing to calculate branch frequencies.
706 @LambdaForm.Hidden
707 @jdk.internal.HotSpotIntrinsicCandidate
708 static
709 boolean profileBoolean(boolean result, int[] counters) {
710 // Profile is int[2] where [0] and [1] correspond to false and true occurrences respectively.
711 int idx = result ? 1 : 0;
712 try {
713 counters[idx] = Math.addExact(counters[idx], 1);
714 } catch (ArithmeticException e) {
715 // Avoid continuous overflow by halving the problematic count.
716 counters[idx] = counters[idx] / 2;
717 }
718 return result;
719 }
720
721 // Intrinsified by C2. Returns true if obj is a compile-time constant.
722 @LambdaForm.Hidden
723 @jdk.internal.HotSpotIntrinsicCandidate
724 static
725 boolean isCompileConstant(Object obj) {
726 return false;
727 }
728
729 static
730 MethodHandle makeGuardWithTest(MethodHandle test,
731 MethodHandle target,
732 MethodHandle fallback) {
733 MethodType type = target.type();
734 assert(test.type().equals(type.changeReturnType(boolean.class)) && fallback.type().equals(type));
735 MethodType basicType = type.basicType();
736 LambdaForm form = makeGuardWithTestForm(basicType);
737 BoundMethodHandle mh;
738 try {
739 if (PROFILE_GWT) {
740 int[] counts = new int[2];
741 mh = (BoundMethodHandle)
742 BoundMethodHandle.speciesData_LLLL().constructor().invokeBasic(type, form,
743 (Object) test, (Object) profile(target), (Object) profile(fallback), counts);
744 } else {
745 mh = (BoundMethodHandle)
746 BoundMethodHandle.speciesData_LLL().constructor().invokeBasic(type, form,
747 (Object) test, (Object) profile(target), (Object) profile(fallback));
748 }
749 } catch (Throwable ex) {
750 throw uncaughtException(ex);
751 }
752 assert(mh.type() == type);
753 return mh;
754 }
755
756
757 static
758 MethodHandle profile(MethodHandle target) {
759 if (DONT_INLINE_THRESHOLD >= 0) {
760 return makeBlockInliningWrapper(target);
761 } else {
762 return target;
763 }
764 }
765
766 /**
767 * Block inlining during JIT-compilation of a target method handle if it hasn't been invoked enough times.
768 * Corresponding LambdaForm has @DontInline when compiled into bytecode.
769 */
770 static
771 MethodHandle makeBlockInliningWrapper(MethodHandle target) {
772 LambdaForm lform;
773 if (DONT_INLINE_THRESHOLD > 0) {
774 lform = Makers.PRODUCE_BLOCK_INLINING_FORM.apply(target);
775 } else {
776 lform = Makers.PRODUCE_REINVOKER_FORM.apply(target);
777 }
778 return new CountingWrapper(target, lform,
779 Makers.PRODUCE_BLOCK_INLINING_FORM, Makers.PRODUCE_REINVOKER_FORM,
780 DONT_INLINE_THRESHOLD);
781 }
782
783 private final static class Makers {
784 /** Constructs reinvoker lambda form which block inlining during JIT-compilation for a particular method handle */
785 static final Function<MethodHandle, LambdaForm> PRODUCE_BLOCK_INLINING_FORM = new Function<MethodHandle, LambdaForm>() {
786 @Override
787 public LambdaForm apply(MethodHandle target) {
788 return DelegatingMethodHandle.makeReinvokerForm(target,
789 MethodTypeForm.LF_DELEGATE_BLOCK_INLINING, CountingWrapper.class, "reinvoker.dontInline", false,
790 DelegatingMethodHandle.NF_getTarget, CountingWrapper.NF_maybeStopCounting);
791 }
792 };
793
794 /** Constructs simple reinvoker lambda form for a particular method handle */
795 static final Function<MethodHandle, LambdaForm> PRODUCE_REINVOKER_FORM = new Function<MethodHandle, LambdaForm>() {
796 @Override
797 public LambdaForm apply(MethodHandle target) {
798 return DelegatingMethodHandle.makeReinvokerForm(target,
799 MethodTypeForm.LF_DELEGATE, DelegatingMethodHandle.class, DelegatingMethodHandle.NF_getTarget);
800 }
801 };
802
803 /** Maker of type-polymorphic varargs */
804 static final ClassValue<MethodHandle[]> TYPED_COLLECTORS = new ClassValue<MethodHandle[]>() {
805 @Override
806 protected MethodHandle[] computeValue(Class<?> type) {
807 return new MethodHandle[MAX_JVM_ARITY + 1];
808 }
809 };
810 }
811
812 /**
813 * Counting method handle. It has 2 states: counting and non-counting.
814 * It is in counting state for the first n invocations and then transitions to non-counting state.
815 * Behavior in counting and non-counting states is determined by lambda forms produced by
816 * countingFormProducer & nonCountingFormProducer respectively.
817 */
818 static class CountingWrapper extends DelegatingMethodHandle {
819 private final MethodHandle target;
820 private int count;
821 private Function<MethodHandle, LambdaForm> countingFormProducer;
822 private Function<MethodHandle, LambdaForm> nonCountingFormProducer;
823 private volatile boolean isCounting;
824
825 private CountingWrapper(MethodHandle target, LambdaForm lform,
826 Function<MethodHandle, LambdaForm> countingFromProducer,
827 Function<MethodHandle, LambdaForm> nonCountingFormProducer,
828 int count) {
829 super(target.type(), lform);
830 this.target = target;
831 this.count = count;
832 this.countingFormProducer = countingFromProducer;
833 this.nonCountingFormProducer = nonCountingFormProducer;
834 this.isCounting = (count > 0);
835 }
836
837 @Hidden
838 @Override
839 protected MethodHandle getTarget() {
840 return target;
841 }
842
843 @Override
844 public MethodHandle asTypeUncached(MethodType newType) {
845 MethodHandle newTarget = target.asType(newType);
846 MethodHandle wrapper;
847 if (isCounting) {
848 LambdaForm lform;
849 lform = countingFormProducer.apply(newTarget);
850 wrapper = new CountingWrapper(newTarget, lform, countingFormProducer, nonCountingFormProducer, DONT_INLINE_THRESHOLD);
851 } else {
852 wrapper = newTarget; // no need for a counting wrapper anymore
853 }
854 return (asTypeCache = wrapper);
855 }
856
857 // Customize target if counting happens for too long.
858 private int invocations = CUSTOMIZE_THRESHOLD;
859 private void maybeCustomizeTarget() {
860 int c = invocations;
861 if (c >= 0) {
862 if (c == 1) {
863 target.customize();
864 }
865 invocations = c - 1;
866 }
867 }
868
869 boolean countDown() {
870 int c = count;
871 maybeCustomizeTarget();
872 if (c <= 1) {
873 // Try to limit number of updates. MethodHandle.updateForm() doesn't guarantee LF update visibility.
874 if (isCounting) {
875 isCounting = false;
876 return true;
877 } else {
878 return false;
879 }
880 } else {
881 count = c - 1;
882 return false;
883 }
884 }
885
886 @Hidden
887 static void maybeStopCounting(Object o1) {
888 CountingWrapper wrapper = (CountingWrapper) o1;
889 if (wrapper.countDown()) {
890 // Reached invocation threshold. Replace counting behavior with a non-counting one.
891 LambdaForm lform = wrapper.nonCountingFormProducer.apply(wrapper.target);
892 lform.compileToBytecode(); // speed up warmup by avoiding LF interpretation again after transition
893 wrapper.updateForm(lform);
894 }
895 }
896
897 static final NamedFunction NF_maybeStopCounting;
898 static {
899 Class<?> THIS_CLASS = CountingWrapper.class;
900 try {
901 NF_maybeStopCounting = new NamedFunction(THIS_CLASS.getDeclaredMethod("maybeStopCounting", Object.class));
902 } catch (ReflectiveOperationException ex) {
903 throw newInternalError(ex);
904 }
905 }
906 }
907
908 static
909 LambdaForm makeGuardWithTestForm(MethodType basicType) {
910 LambdaForm lform = basicType.form().cachedLambdaForm(MethodTypeForm.LF_GWT);
911 if (lform != null) return lform;
912 final int THIS_MH = 0; // the BMH_LLL
913 final int ARG_BASE = 1; // start of incoming arguments
914 final int ARG_LIMIT = ARG_BASE + basicType.parameterCount();
915 int nameCursor = ARG_LIMIT;
916 final int GET_TEST = nameCursor++;
917 final int GET_TARGET = nameCursor++;
918 final int GET_FALLBACK = nameCursor++;
919 final int GET_COUNTERS = PROFILE_GWT ? nameCursor++ : -1;
920 final int CALL_TEST = nameCursor++;
921 final int PROFILE = (GET_COUNTERS != -1) ? nameCursor++ : -1;
922 final int TEST = nameCursor-1; // previous statement: either PROFILE or CALL_TEST
923 final int SELECT_ALT = nameCursor++;
924 final int CALL_TARGET = nameCursor++;
925 assert(CALL_TARGET == SELECT_ALT+1); // must be true to trigger IBG.emitSelectAlternative
926
927 MethodType lambdaType = basicType.invokerType();
928 Name[] names = arguments(nameCursor - ARG_LIMIT, lambdaType);
929
930 BoundMethodHandle.SpeciesData data =
931 (GET_COUNTERS != -1) ? BoundMethodHandle.speciesData_LLLL()
932 : BoundMethodHandle.speciesData_LLL();
933 names[THIS_MH] = names[THIS_MH].withConstraint(data);
934 names[GET_TEST] = new Name(data.getterFunction(0), names[THIS_MH]);
935 names[GET_TARGET] = new Name(data.getterFunction(1), names[THIS_MH]);
936 names[GET_FALLBACK] = new Name(data.getterFunction(2), names[THIS_MH]);
937 if (GET_COUNTERS != -1) {
938 names[GET_COUNTERS] = new Name(data.getterFunction(3), names[THIS_MH]);
939 }
940 Object[] invokeArgs = Arrays.copyOfRange(names, 0, ARG_LIMIT, Object[].class);
941
942 // call test
943 MethodType testType = basicType.changeReturnType(boolean.class).basicType();
944 invokeArgs[0] = names[GET_TEST];
945 names[CALL_TEST] = new Name(testType, invokeArgs);
946
947 // profile branch
948 if (PROFILE != -1) {
949 names[PROFILE] = new Name(NF_profileBoolean, names[CALL_TEST], names[GET_COUNTERS]);
950 }
951 // call selectAlternative
952 names[SELECT_ALT] = new Name(getConstantHandle(MH_selectAlternative), names[TEST], names[GET_TARGET], names[GET_FALLBACK]);
953
954 // call target or fallback
955 invokeArgs[0] = names[SELECT_ALT];
956 names[CALL_TARGET] = new Name(basicType, invokeArgs);
957
958 lform = new LambdaForm("guard", lambdaType.parameterCount(), names, /*forceInline=*/true);
959
960 return basicType.form().setCachedLambdaForm(MethodTypeForm.LF_GWT, lform);
961 }
962
963 /**
964 * The LambdaForm shape for catchException combinator is the following:
965 * <blockquote><pre>{@code
966 * guardWithCatch=Lambda(a0:L,a1:L,a2:L)=>{
967 * t3:L=BoundMethodHandle$Species_LLLLL.argL0(a0:L);
968 * t4:L=BoundMethodHandle$Species_LLLLL.argL1(a0:L);
969 * t5:L=BoundMethodHandle$Species_LLLLL.argL2(a0:L);
970 * t6:L=BoundMethodHandle$Species_LLLLL.argL3(a0:L);
971 * t7:L=BoundMethodHandle$Species_LLLLL.argL4(a0:L);
972 * t8:L=MethodHandle.invokeBasic(t6:L,a1:L,a2:L);
973 * t9:L=MethodHandleImpl.guardWithCatch(t3:L,t4:L,t5:L,t8:L);
974 * t10:I=MethodHandle.invokeBasic(t7:L,t9:L);t10:I}
975 * }</pre></blockquote>
976 *
977 * argL0 and argL2 are target and catcher method handles. argL1 is exception class.
978 * argL3 and argL4 are auxiliary method handles: argL3 boxes arguments and wraps them into Object[]
979 * (ValueConversions.array()) and argL4 unboxes result if necessary (ValueConversions.unbox()).
980 *
981 * Having t8 and t10 passed outside and not hardcoded into a lambda form allows to share lambda forms
982 * among catchException combinators with the same basic type.
983 */
984 private static LambdaForm makeGuardWithCatchForm(MethodType basicType) {
985 MethodType lambdaType = basicType.invokerType();
986
987 LambdaForm lform = basicType.form().cachedLambdaForm(MethodTypeForm.LF_GWC);
988 if (lform != null) {
989 return lform;
990 }
991 final int THIS_MH = 0; // the BMH_LLLLL
992 final int ARG_BASE = 1; // start of incoming arguments
993 final int ARG_LIMIT = ARG_BASE + basicType.parameterCount();
994
995 int nameCursor = ARG_LIMIT;
996 final int GET_TARGET = nameCursor++;
997 final int GET_CLASS = nameCursor++;
998 final int GET_CATCHER = nameCursor++;
999 final int GET_COLLECT_ARGS = nameCursor++;
1000 final int GET_UNBOX_RESULT = nameCursor++;
1001 final int BOXED_ARGS = nameCursor++;
1002 final int TRY_CATCH = nameCursor++;
1003 final int UNBOX_RESULT = nameCursor++;
1004
1005 Name[] names = arguments(nameCursor - ARG_LIMIT, lambdaType);
1006
1007 BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_LLLLL();
1008 names[THIS_MH] = names[THIS_MH].withConstraint(data);
1009 names[GET_TARGET] = new Name(data.getterFunction(0), names[THIS_MH]);
1010 names[GET_CLASS] = new Name(data.getterFunction(1), names[THIS_MH]);
1011 names[GET_CATCHER] = new Name(data.getterFunction(2), names[THIS_MH]);
1012 names[GET_COLLECT_ARGS] = new Name(data.getterFunction(3), names[THIS_MH]);
1013 names[GET_UNBOX_RESULT] = new Name(data.getterFunction(4), names[THIS_MH]);
1014
1015 // FIXME: rework argument boxing/result unboxing logic for LF interpretation
1016
1017 // t_{i}:L=MethodHandle.invokeBasic(collectArgs:L,a1:L,...);
1018 MethodType collectArgsType = basicType.changeReturnType(Object.class);
1019 MethodHandle invokeBasic = MethodHandles.basicInvoker(collectArgsType);
1020 Object[] args = new Object[invokeBasic.type().parameterCount()];
1021 args[0] = names[GET_COLLECT_ARGS];
1022 System.arraycopy(names, ARG_BASE, args, 1, ARG_LIMIT-ARG_BASE);
1023 names[BOXED_ARGS] = new Name(makeIntrinsic(invokeBasic, Intrinsic.GUARD_WITH_CATCH), args);
1024
1025 // t_{i+1}:L=MethodHandleImpl.guardWithCatch(target:L,exType:L,catcher:L,t_{i}:L);
1026 Object[] gwcArgs = new Object[] {names[GET_TARGET], names[GET_CLASS], names[GET_CATCHER], names[BOXED_ARGS]};
1027 names[TRY_CATCH] = new Name(NF_guardWithCatch, gwcArgs);
1028
1029 // t_{i+2}:I=MethodHandle.invokeBasic(unbox:L,t_{i+1}:L);
1030 MethodHandle invokeBasicUnbox = MethodHandles.basicInvoker(MethodType.methodType(basicType.rtype(), Object.class));
1031 Object[] unboxArgs = new Object[] {names[GET_UNBOX_RESULT], names[TRY_CATCH]};
1032 names[UNBOX_RESULT] = new Name(invokeBasicUnbox, unboxArgs);
1033
1034 lform = new LambdaForm("guardWithCatch", lambdaType.parameterCount(), names);
1035
1036 return basicType.form().setCachedLambdaForm(MethodTypeForm.LF_GWC, lform);
1037 }
1038
1039 static
1040 MethodHandle makeGuardWithCatch(MethodHandle target,
1041 Class<? extends Throwable> exType,
1042 MethodHandle catcher) {
1043 MethodType type = target.type();
1044 LambdaForm form = makeGuardWithCatchForm(type.basicType());
1045
1046 // Prepare auxiliary method handles used during LambdaForm interpretation.
1047 // Box arguments and wrap them into Object[]: ValueConversions.array().
1048 MethodType varargsType = type.changeReturnType(Object[].class);
1049 MethodHandle collectArgs = varargsArray(type.parameterCount()).asType(varargsType);
1050 MethodHandle unboxResult = unboxResultHandle(type.returnType());
1051
1052 BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_LLLLL();
1053 BoundMethodHandle mh;
1054 try {
1055 mh = (BoundMethodHandle) data.constructor().invokeBasic(type, form, (Object) target, (Object) exType,
1056 (Object) catcher, (Object) collectArgs, (Object) unboxResult);
1057 } catch (Throwable ex) {
1058 throw uncaughtException(ex);
1059 }
1060 assert(mh.type() == type);
1061 return mh;
1062 }
1063
1064 /**
1065 * Intrinsified during LambdaForm compilation
1066 * (see {@link InvokerBytecodeGenerator#emitGuardWithCatch emitGuardWithCatch}).
1067 */
1068 @LambdaForm.Hidden
1069 static Object guardWithCatch(MethodHandle target, Class<? extends Throwable> exType, MethodHandle catcher,
1070 Object... av) throws Throwable {
1071 // Use asFixedArity() to avoid unnecessary boxing of last argument for VarargsCollector case.
1072 try {
1073 return target.asFixedArity().invokeWithArguments(av);
1074 } catch (Throwable t) {
1075 if (!exType.isInstance(t)) throw t;
1076 return catcher.asFixedArity().invokeWithArguments(prepend(av, t));
1077 }
1078 }
1079
1080 /** Prepend elements to an array. */
1081 @LambdaForm.Hidden
1082 private static Object[] prepend(Object[] array, Object... elems) {
1083 int nArray = array.length;
1084 int nElems = elems.length;
1085 Object[] newArray = new Object[nArray + nElems];
1086 System.arraycopy(elems, 0, newArray, 0, nElems);
1087 System.arraycopy(array, 0, newArray, nElems, nArray);
1088 return newArray;
1089 }
1090
1091 static
1092 MethodHandle throwException(MethodType type) {
1093 assert(Throwable.class.isAssignableFrom(type.parameterType(0)));
1094 int arity = type.parameterCount();
1095 if (arity > 1) {
1096 MethodHandle mh = throwException(type.dropParameterTypes(1, arity));
1097 mh = MethodHandles.dropArguments(mh, 1, type.parameterList().subList(1, arity));
1098 return mh;
1099 }
1100 return makePairwiseConvert(NF_throwException.resolvedHandle(), type, false, true);
1101 }
1102
1103 static <T extends Throwable> Empty throwException(T t) throws T { throw t; }
1104
1105 static MethodHandle[] FAKE_METHOD_HANDLE_INVOKE = new MethodHandle[2];
1106 static MethodHandle fakeMethodHandleInvoke(MemberName method) {
1107 int idx;
1108 assert(method.isMethodHandleInvoke());
1109 switch (method.getName()) {
1110 case "invoke": idx = 0; break;
1111 case "invokeExact": idx = 1; break;
1112 default: throw new InternalError(method.getName());
1113 }
1114 MethodHandle mh = FAKE_METHOD_HANDLE_INVOKE[idx];
1115 if (mh != null) return mh;
1116 MethodType type = MethodType.methodType(Object.class, UnsupportedOperationException.class,
1117 MethodHandle.class, Object[].class);
1118 mh = throwException(type);
1119 mh = mh.bindTo(new UnsupportedOperationException("cannot reflectively invoke MethodHandle"));
1120 if (!method.getInvocationType().equals(mh.type()))
1121 throw new InternalError(method.toString());
1122 mh = mh.withInternalMemberName(method, false);
1123 mh = mh.withVarargs(true);
1124 assert(method.isVarargs());
1125 FAKE_METHOD_HANDLE_INVOKE[idx] = mh;
1126 return mh;
1127 }
1128 static MethodHandle fakeVarHandleInvoke(MemberName method) {
1129 // TODO caching, is it necessary?
1130 MethodType type = MethodType.methodType(method.getReturnType(), UnsupportedOperationException.class,
1131 VarHandle.class, Object[].class);
1132 MethodHandle mh = throwException(type);
1133 mh = mh.bindTo(new UnsupportedOperationException("cannot reflectively invoke VarHandle"));
1134 if (!method.getInvocationType().equals(mh.type()))
1135 throw new InternalError(method.toString());
1136 mh = mh.withInternalMemberName(method, false);
1137 mh = mh.asVarargsCollector(Object[].class);
1138 assert(method.isVarargs());
1139 return mh;
1140 }
1141
1142 /**
1143 * Create an alias for the method handle which, when called,
1144 * appears to be called from the same class loader and protection domain
1145 * as hostClass.
1146 * This is an expensive no-op unless the method which is called
1147 * is sensitive to its caller. A small number of system methods
1148 * are in this category, including Class.forName and Method.invoke.
1149 */
1150 static
1151 MethodHandle bindCaller(MethodHandle mh, Class<?> hostClass) {
1152 return BindCaller.bindCaller(mh, hostClass);
1153 }
1154
1155 // Put the whole mess into its own nested class.
1156 // That way we can lazily load the code and set up the constants.
1157 private static class BindCaller {
1158 private static MethodType INVOKER_MT = MethodType.methodType(Object.class, MethodHandle.class, Object[].class);
1159
1160 static
1161 MethodHandle bindCaller(MethodHandle mh, Class<?> hostClass) {
1162 // Do not use this function to inject calls into system classes.
1163 if (hostClass == null
1164 || (hostClass.isArray() ||
1165 hostClass.isPrimitive() ||
1166 hostClass.getName().startsWith("java.") ||
1167 hostClass.getName().startsWith("sun."))) {
1168 throw new InternalError(); // does not happen, and should not anyway
1169 }
1170 // For simplicity, convert mh to a varargs-like method.
1171 MethodHandle vamh = prepareForInvoker(mh);
1172 // Cache the result of makeInjectedInvoker once per argument class.
1173 MethodHandle bccInvoker = CV_makeInjectedInvoker.get(hostClass);
1174 return restoreToType(bccInvoker.bindTo(vamh), mh, hostClass);
1175 }
1176
1177 private static MethodHandle makeInjectedInvoker(Class<?> hostClass) {
1178 try {
1179 Class<?> invokerClass = UNSAFE.defineAnonymousClass(hostClass, INJECTED_INVOKER_TEMPLATE, null);
1180 assert checkInjectedInvoker(hostClass, invokerClass);
1181 return IMPL_LOOKUP.findStatic(invokerClass, "invoke_V", INVOKER_MT);
1182 } catch (ReflectiveOperationException ex) {
1183 throw uncaughtException(ex);
1184 }
1185 }
1186
1187 private static ClassValue<MethodHandle> CV_makeInjectedInvoker = new ClassValue<MethodHandle>() {
1188 @Override protected MethodHandle computeValue(Class<?> hostClass) {
1189 return makeInjectedInvoker(hostClass);
1190 }
1191 };
1192
1193 // Adapt mh so that it can be called directly from an injected invoker:
1194 private static MethodHandle prepareForInvoker(MethodHandle mh) {
1195 mh = mh.asFixedArity();
1196 MethodType mt = mh.type();
1197 int arity = mt.parameterCount();
1198 MethodHandle vamh = mh.asType(mt.generic());
1199 vamh.internalForm().compileToBytecode(); // eliminate LFI stack frames
1200 vamh = vamh.asSpreader(Object[].class, arity);
1201 vamh.internalForm().compileToBytecode(); // eliminate LFI stack frames
1202 return vamh;
1203 }
1204
1205 // Undo the adapter effect of prepareForInvoker:
1206 private static MethodHandle restoreToType(MethodHandle vamh,
1207 MethodHandle original,
1208 Class<?> hostClass) {
1209 MethodType type = original.type();
1210 MethodHandle mh = vamh.asCollector(Object[].class, type.parameterCount());
1211 MemberName member = original.internalMemberName();
1212 mh = mh.asType(type);
1213 mh = new WrappedMember(mh, type, member, original.isInvokeSpecial(), hostClass);
1214 return mh;
1215 }
1216
1217 private static boolean checkInjectedInvoker(Class<?> hostClass, Class<?> invokerClass) {
1218 assert (hostClass.getClassLoader() == invokerClass.getClassLoader()) : hostClass.getName()+" (CL)";
1219 try {
1220 assert (hostClass.getProtectionDomain() == invokerClass.getProtectionDomain()) : hostClass.getName()+" (PD)";
1221 } catch (SecurityException ex) {
1222 // Self-check was blocked by security manager. This is OK.
1223 }
1224 try {
1225 // Test the invoker to ensure that it really injects into the right place.
1226 MethodHandle invoker = IMPL_LOOKUP.findStatic(invokerClass, "invoke_V", INVOKER_MT);
1227 MethodHandle vamh = prepareForInvoker(MH_checkCallerClass);
1228 return (boolean)invoker.invoke(vamh, new Object[]{ invokerClass });
1229 } catch (Throwable ex) {
1230 throw new InternalError(ex);
1231 }
1232 }
1233
1234 private static final MethodHandle MH_checkCallerClass;
1235 static {
1236 final Class<?> THIS_CLASS = BindCaller.class;
1237 assert(checkCallerClass(THIS_CLASS));
1238 try {
1239 MH_checkCallerClass = IMPL_LOOKUP
1240 .findStatic(THIS_CLASS, "checkCallerClass",
1241 MethodType.methodType(boolean.class, Class.class));
1242 assert((boolean) MH_checkCallerClass.invokeExact(THIS_CLASS));
1243 } catch (Throwable ex) {
1244 throw new InternalError(ex);
1245 }
1246 }
1247
1248 @CallerSensitive
1249 @ForceInline
1250 private static boolean checkCallerClass(Class<?> expected) {
1251 // This method is called via MH_checkCallerClass and so it's correct to ask for the immediate caller here.
1252 Class<?> actual = Reflection.getCallerClass();
1253 if (actual != expected)
1254 throw new InternalError("found " + actual.getName() + ", expected " + expected.getName());
1255 return true;
1256 }
1257
1258 private static final byte[] INJECTED_INVOKER_TEMPLATE = generateInvokerTemplate();
1259
1260 /** Produces byte code for a class that is used as an injected invoker. */
1261 private static byte[] generateInvokerTemplate() {
1262 ClassWriter cw = new ClassWriter(0);
1263
1264 // private static class InjectedInvoker {
1265 // @Hidden
1266 // static Object invoke_V(MethodHandle vamh, Object[] args) throws Throwable {
1267 // return vamh.invokeExact(args);
1268 // }
1269 // }
1270 cw.visit(52, ACC_PRIVATE | ACC_SUPER, "InjectedInvoker", null, "java/lang/Object", null);
1271
1272 MethodVisitor mv = cw.visitMethod(ACC_STATIC, "invoke_V",
1273 "(Ljava/lang/invoke/MethodHandle;[Ljava/lang/Object;)Ljava/lang/Object;",
1274 null, null);
1275
1276 // Suppress invoker method in stack traces.
1277 AnnotationVisitor av0 = mv.visitAnnotation("Ljava/lang/invoke/LambdaForm$Hidden;", true);
1278 av0.visitEnd();
1279
1280 mv.visitCode();
1281 mv.visitVarInsn(ALOAD, 0);
1282 mv.visitVarInsn(ALOAD, 1);
1283 mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/invoke/MethodHandle", "invokeExact",
1284 "([Ljava/lang/Object;)Ljava/lang/Object;", false);
1285 mv.visitInsn(ARETURN);
1286 mv.visitMaxs(2, 2);
1287 mv.visitEnd();
1288
1289 cw.visitEnd();
1290 return cw.toByteArray();
1291 }
1292 }
1293
1294 /** This subclass allows a wrapped method handle to be re-associated with an arbitrary member name. */
1295 private static final class WrappedMember extends DelegatingMethodHandle {
1296 private final MethodHandle target;
1297 private final MemberName member;
1298 private final Class<?> callerClass;
1299 private final boolean isInvokeSpecial;
1300
1301 private WrappedMember(MethodHandle target, MethodType type,
1302 MemberName member, boolean isInvokeSpecial,
1303 Class<?> callerClass) {
1304 super(type, target);
1305 this.target = target;
1306 this.member = member;
1307 this.callerClass = callerClass;
1308 this.isInvokeSpecial = isInvokeSpecial;
1309 }
1310
1311 @Override
1312 MemberName internalMemberName() {
1313 return member;
1314 }
1315 @Override
1316 Class<?> internalCallerClass() {
1317 return callerClass;
1318 }
1319 @Override
1320 boolean isInvokeSpecial() {
1321 return isInvokeSpecial;
1322 }
1323 @Override
1324 protected MethodHandle getTarget() {
1325 return target;
1326 }
1327 @Override
1328 public MethodHandle asTypeUncached(MethodType newType) {
1329 // This MH is an alias for target, except for the MemberName
1330 // Drop the MemberName if there is any conversion.
1331 return asTypeCache = target.asType(newType);
1332 }
1333 }
1334
1335 static MethodHandle makeWrappedMember(MethodHandle target, MemberName member, boolean isInvokeSpecial) {
1336 if (member.equals(target.internalMemberName()) && isInvokeSpecial == target.isInvokeSpecial())
1337 return target;
1338 return new WrappedMember(target, target.type(), member, isInvokeSpecial, null);
1339 }
1340
1341 /** Intrinsic IDs */
1342 /*non-public*/
1343 enum Intrinsic {
1344 SELECT_ALTERNATIVE,
1345 GUARD_WITH_CATCH,
1346 TRY_FINALLY,
1347 LOOP,
1348 NEW_ARRAY,
1349 ARRAY_LOAD,
1350 ARRAY_STORE,
1351 ARRAY_LENGTH,
1352 IDENTITY,
1353 ZERO,
1354 NONE // no intrinsic associated
1355 }
1356
1357 /** Mark arbitrary method handle as intrinsic.
1358 * InvokerBytecodeGenerator uses this info to produce more efficient bytecode shape. */
1359 static final class IntrinsicMethodHandle extends DelegatingMethodHandle {
1360 private final MethodHandle target;
1361 private final Intrinsic intrinsicName;
1362
1363 IntrinsicMethodHandle(MethodHandle target, Intrinsic intrinsicName) {
1364 super(target.type(), target);
1365 this.target = target;
1366 this.intrinsicName = intrinsicName;
1367 }
1368
1369 @Override
1370 protected MethodHandle getTarget() {
1371 return target;
1372 }
1373
1374 @Override
1375 Intrinsic intrinsicName() {
1376 return intrinsicName;
1377 }
1378
1379 @Override
1380 public MethodHandle asTypeUncached(MethodType newType) {
1381 // This MH is an alias for target, except for the intrinsic name
1382 // Drop the name if there is any conversion.
1383 return asTypeCache = target.asType(newType);
1384 }
1385
1386 @Override
1387 String internalProperties() {
1388 return super.internalProperties() +
1389 "\n& Intrinsic="+intrinsicName;
1390 }
1391
1392 @Override
1393 public MethodHandle asCollector(Class<?> arrayType, int arrayLength) {
1394 if (intrinsicName == Intrinsic.IDENTITY) {
1395 MethodType resultType = type().asCollectorType(arrayType, type().parameterCount() - 1, arrayLength);
1396 MethodHandle newArray = MethodHandleImpl.varargsArray(arrayType, arrayLength);
1397 return newArray.asType(resultType);
1398 }
1399 return super.asCollector(arrayType, arrayLength);
1400 }
1401 }
1402
1403 static MethodHandle makeIntrinsic(MethodHandle target, Intrinsic intrinsicName) {
1404 if (intrinsicName == target.intrinsicName())
1405 return target;
1406 return new IntrinsicMethodHandle(target, intrinsicName);
1407 }
1408
1409 static MethodHandle makeIntrinsic(MethodType type, LambdaForm form, Intrinsic intrinsicName) {
1410 return new IntrinsicMethodHandle(SimpleMethodHandle.make(type, form), intrinsicName);
1411 }
1412
1413 /// Collection of multiple arguments.
1414
1415 private static MethodHandle findCollector(String name, int nargs, Class<?> rtype, Class<?>... ptypes) {
1416 MethodType type = MethodType.genericMethodType(nargs)
1417 .changeReturnType(rtype)
1418 .insertParameterTypes(0, ptypes);
1419 try {
1420 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, name, type);
1421 } catch (ReflectiveOperationException ex) {
1422 return null;
1423 }
1424 }
1425
1426 private static final Object[] NO_ARGS_ARRAY = {};
1427 private static Object[] makeArray(Object... args) { return args; }
1428 private static Object[] array() { return NO_ARGS_ARRAY; }
1429 private static Object[] array(Object a0)
1430 { return makeArray(a0); }
1431 private static Object[] array(Object a0, Object a1)
1432 { return makeArray(a0, a1); }
1433 private static Object[] array(Object a0, Object a1, Object a2)
1434 { return makeArray(a0, a1, a2); }
1435 private static Object[] array(Object a0, Object a1, Object a2, Object a3)
1436 { return makeArray(a0, a1, a2, a3); }
1437 private static Object[] array(Object a0, Object a1, Object a2, Object a3,
1438 Object a4)
1439 { return makeArray(a0, a1, a2, a3, a4); }
1440 private static Object[] array(Object a0, Object a1, Object a2, Object a3,
1441 Object a4, Object a5)
1442 { return makeArray(a0, a1, a2, a3, a4, a5); }
1443 private static Object[] array(Object a0, Object a1, Object a2, Object a3,
1444 Object a4, Object a5, Object a6)
1445 { return makeArray(a0, a1, a2, a3, a4, a5, a6); }
1446 private static Object[] array(Object a0, Object a1, Object a2, Object a3,
1447 Object a4, Object a5, Object a6, Object a7)
1448 { return makeArray(a0, a1, a2, a3, a4, a5, a6, a7); }
1449 private static Object[] array(Object a0, Object a1, Object a2, Object a3,
1450 Object a4, Object a5, Object a6, Object a7,
1451 Object a8)
1452 { return makeArray(a0, a1, a2, a3, a4, a5, a6, a7, a8); }
1453 private static Object[] array(Object a0, Object a1, Object a2, Object a3,
1454 Object a4, Object a5, Object a6, Object a7,
1455 Object a8, Object a9)
1456 { return makeArray(a0, a1, a2, a3, a4, a5, a6, a7, a8, a9); }
1457
1458 private static final int ARRAYS_COUNT = 11;
1459 private static final @Stable MethodHandle[] ARRAYS = new MethodHandle[MAX_ARITY + 1];
1460
1461 // filling versions of the above:
1462 // using Integer len instead of int len and no varargs to avoid bootstrapping problems
1463 private static Object[] fillNewArray(Integer len, Object[] /*not ...*/ args) {
1464 Object[] a = new Object[len];
1465 fillWithArguments(a, 0, args);
1466 return a;
1467 }
1468 private static Object[] fillNewTypedArray(Object[] example, Integer len, Object[] /*not ...*/ args) {
1469 Object[] a = Arrays.copyOf(example, len);
1470 assert(a.getClass() != Object[].class);
1471 fillWithArguments(a, 0, args);
1472 return a;
1473 }
1474 private static void fillWithArguments(Object[] a, int pos, Object... args) {
1475 System.arraycopy(args, 0, a, pos, args.length);
1476 }
1477 // using Integer pos instead of int pos to avoid bootstrapping problems
1478 private static Object[] fillArray(Integer pos, Object[] a, Object a0)
1479 { fillWithArguments(a, pos, a0); return a; }
1480 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1)
1481 { fillWithArguments(a, pos, a0, a1); return a; }
1482 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2)
1483 { fillWithArguments(a, pos, a0, a1, a2); return a; }
1484 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3)
1485 { fillWithArguments(a, pos, a0, a1, a2, a3); return a; }
1486 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3,
1487 Object a4)
1488 { fillWithArguments(a, pos, a0, a1, a2, a3, a4); return a; }
1489 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3,
1490 Object a4, Object a5)
1491 { fillWithArguments(a, pos, a0, a1, a2, a3, a4, a5); return a; }
1492 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3,
1493 Object a4, Object a5, Object a6)
1494 { fillWithArguments(a, pos, a0, a1, a2, a3, a4, a5, a6); return a; }
1495 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3,
1496 Object a4, Object a5, Object a6, Object a7)
1497 { fillWithArguments(a, pos, a0, a1, a2, a3, a4, a5, a6, a7); return a; }
1498 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3,
1499 Object a4, Object a5, Object a6, Object a7,
1500 Object a8)
1501 { fillWithArguments(a, pos, a0, a1, a2, a3, a4, a5, a6, a7, a8); return a; }
1502 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3,
1503 Object a4, Object a5, Object a6, Object a7,
1504 Object a8, Object a9)
1505 { fillWithArguments(a, pos, a0, a1, a2, a3, a4, a5, a6, a7, a8, a9); return a; }
1506
1507 private static final int FILL_ARRAYS_COUNT = 11; // current number of fillArray methods
1508 private static final @Stable MethodHandle[] FILL_ARRAYS = new MethodHandle[FILL_ARRAYS_COUNT];
1509
1510 private static MethodHandle getFillArray(int count) {
1511 assert (count > 0 && count < FILL_ARRAYS_COUNT);
1512 MethodHandle mh = FILL_ARRAYS[count];
1513 if (mh != null) {
1514 return mh;
1515 }
1516 mh = findCollector("fillArray", count, Object[].class, Integer.class, Object[].class);
1517 FILL_ARRAYS[count] = mh;
1518 return mh;
1519 }
1520
1521 private static Object copyAsPrimitiveArray(Wrapper w, Object... boxes) {
1522 Object a = w.makeArray(boxes.length);
1523 w.copyArrayUnboxing(boxes, 0, a, 0, boxes.length);
1524 return a;
1525 }
1526
1527 /** Return a method handle that takes the indicated number of Object
1528 * arguments and returns an Object array of them, as if for varargs.
1529 */
1530 static MethodHandle varargsArray(int nargs) {
1531 MethodHandle mh = ARRAYS[nargs];
1532 if (mh != null) {
1533 return mh;
1534 }
1535 if (nargs < ARRAYS_COUNT) {
1536 mh = findCollector("array", nargs, Object[].class);
1537 } else {
1538 mh = buildVarargsArray(getConstantHandle(MH_fillNewArray),
1539 getConstantHandle(MH_arrayIdentity), nargs);
1540 }
1541 assert(assertCorrectArity(mh, nargs));
1542 mh = makeIntrinsic(mh, Intrinsic.NEW_ARRAY);
1543 return ARRAYS[nargs] = mh;
1544 }
1545
1546 private static boolean assertCorrectArity(MethodHandle mh, int arity) {
1547 assert(mh.type().parameterCount() == arity) : "arity != "+arity+": "+mh;
1548 return true;
1549 }
1550
1551 // Array identity function (used as getConstantHandle(MH_arrayIdentity)).
1552 static <T> T[] identity(T[] x) {
1553 return x;
1554 }
1555
1556 private static MethodHandle buildVarargsArray(MethodHandle newArray, MethodHandle finisher, int nargs) {
1557 // Build up the result mh as a sequence of fills like this:
1558 // finisher(fill(fill(newArrayWA(23,x1..x10),10,x11..x20),20,x21..x23))
1559 // The various fill(_,10*I,___*[J]) are reusable.
1560 int leftLen = Math.min(nargs, LEFT_ARGS); // absorb some arguments immediately
1561 int rightLen = nargs - leftLen;
1562 MethodHandle leftCollector = newArray.bindTo(nargs);
1563 leftCollector = leftCollector.asCollector(Object[].class, leftLen);
1564 MethodHandle mh = finisher;
1565 if (rightLen > 0) {
1566 MethodHandle rightFiller = fillToRight(LEFT_ARGS + rightLen);
1567 if (mh.equals(getConstantHandle(MH_arrayIdentity)))
1568 mh = rightFiller;
1569 else
1570 mh = MethodHandles.collectArguments(mh, 0, rightFiller);
1571 }
1572 if (mh.equals(getConstantHandle(MH_arrayIdentity)))
1573 mh = leftCollector;
1574 else
1575 mh = MethodHandles.collectArguments(mh, 0, leftCollector);
1576 return mh;
1577 }
1578
1579 private static final int LEFT_ARGS = FILL_ARRAYS_COUNT - 1;
1580 private static final @Stable MethodHandle[] FILL_ARRAY_TO_RIGHT = new MethodHandle[MAX_ARITY + 1];
1581 /** fill_array_to_right(N).invoke(a, argL..arg[N-1])
1582 * fills a[L]..a[N-1] with corresponding arguments,
1583 * and then returns a. The value L is a global constant (LEFT_ARGS).
1584 */
1585 private static MethodHandle fillToRight(int nargs) {
1586 MethodHandle filler = FILL_ARRAY_TO_RIGHT[nargs];
1587 if (filler != null) return filler;
1588 filler = buildFiller(nargs);
1589 assert(assertCorrectArity(filler, nargs - LEFT_ARGS + 1));
1590 return FILL_ARRAY_TO_RIGHT[nargs] = filler;
1591 }
1592 private static MethodHandle buildFiller(int nargs) {
1593 if (nargs <= LEFT_ARGS)
1594 return getConstantHandle(MH_arrayIdentity); // no args to fill; return the array unchanged
1595 // we need room for both mh and a in mh.invoke(a, arg*[nargs])
1596 final int CHUNK = LEFT_ARGS;
1597 int rightLen = nargs % CHUNK;
1598 int midLen = nargs - rightLen;
1599 if (rightLen == 0) {
1600 midLen = nargs - (rightLen = CHUNK);
1601 if (FILL_ARRAY_TO_RIGHT[midLen] == null) {
1602 // build some precursors from left to right
1603 for (int j = LEFT_ARGS % CHUNK; j < midLen; j += CHUNK)
1604 if (j > LEFT_ARGS) fillToRight(j);
1605 }
1606 }
1607 if (midLen < LEFT_ARGS) rightLen = nargs - (midLen = LEFT_ARGS);
1608 assert(rightLen > 0);
1609 MethodHandle midFill = fillToRight(midLen); // recursive fill
1610 MethodHandle rightFill = getFillArray(rightLen).bindTo(midLen); // [midLen..nargs-1]
1611 assert(midFill.type().parameterCount() == 1 + midLen - LEFT_ARGS);
1612 assert(rightFill.type().parameterCount() == 1 + rightLen);
1613
1614 // Combine the two fills:
1615 // right(mid(a, x10..x19), x20..x23)
1616 // The final product will look like this:
1617 // right(mid(newArrayLeft(24, x0..x9), x10..x19), x20..x23)
1618 if (midLen == LEFT_ARGS)
1619 return rightFill;
1620 else
1621 return MethodHandles.collectArguments(rightFill, 0, midFill);
1622 }
1623
1624 static final int MAX_JVM_ARITY = 255; // limit imposed by the JVM
1625
1626 /** Return a method handle that takes the indicated number of
1627 * typed arguments and returns an array of them.
1628 * The type argument is the array type.
1629 */
1630 static MethodHandle varargsArray(Class<?> arrayType, int nargs) {
1631 Class<?> elemType = arrayType.getComponentType();
1632 if (elemType == null) throw new IllegalArgumentException("not an array: "+arrayType);
1633 // FIXME: Need more special casing and caching here.
1634 if (nargs >= MAX_JVM_ARITY/2 - 1) {
1635 int slots = nargs;
1636 final int MAX_ARRAY_SLOTS = MAX_JVM_ARITY - 1; // 1 for receiver MH
1637 if (slots <= MAX_ARRAY_SLOTS && elemType.isPrimitive())
1638 slots *= Wrapper.forPrimitiveType(elemType).stackSlots();
1639 if (slots > MAX_ARRAY_SLOTS)
1640 throw new IllegalArgumentException("too many arguments: "+arrayType.getSimpleName()+", length "+nargs);
1641 }
1642 if (elemType == Object.class)
1643 return varargsArray(nargs);
1644 // other cases: primitive arrays, subtypes of Object[]
1645 MethodHandle cache[] = Makers.TYPED_COLLECTORS.get(elemType);
1646 MethodHandle mh = nargs < cache.length ? cache[nargs] : null;
1647 if (mh != null) return mh;
1648 if (nargs == 0) {
1649 Object example = java.lang.reflect.Array.newInstance(arrayType.getComponentType(), 0);
1650 mh = MethodHandles.constant(arrayType, example);
1651 } else if (elemType.isPrimitive()) {
1652 MethodHandle builder = getConstantHandle(MH_fillNewArray);
1653 MethodHandle producer = buildArrayProducer(arrayType);
1654 mh = buildVarargsArray(builder, producer, nargs);
1655 } else {
1656 Class<? extends Object[]> objArrayType = arrayType.asSubclass(Object[].class);
1657 Object[] example = Arrays.copyOf(NO_ARGS_ARRAY, 0, objArrayType);
1658 MethodHandle builder = getConstantHandle(MH_fillNewTypedArray).bindTo(example);
1659 MethodHandle producer = getConstantHandle(MH_arrayIdentity); // must be weakly typed
1660 mh = buildVarargsArray(builder, producer, nargs);
1661 }
1662 mh = mh.asType(MethodType.methodType(arrayType, Collections.<Class<?>>nCopies(nargs, elemType)));
1663 mh = makeIntrinsic(mh, Intrinsic.NEW_ARRAY);
1664 assert(assertCorrectArity(mh, nargs));
1665 if (nargs < cache.length)
1666 cache[nargs] = mh;
1667 return mh;
1668 }
1669
1670 private static MethodHandle buildArrayProducer(Class<?> arrayType) {
1671 Class<?> elemType = arrayType.getComponentType();
1672 assert(elemType.isPrimitive());
1673 return getConstantHandle(MH_copyAsPrimitiveArray).bindTo(Wrapper.forPrimitiveType(elemType));
1674 }
1675
1676 /*non-public*/ static void assertSame(Object mh1, Object mh2) {
1677 if (mh1 != mh2) {
1678 String msg = String.format("mh1 != mh2: mh1 = %s (form: %s); mh2 = %s (form: %s)",
1679 mh1, ((MethodHandle)mh1).form,
1680 mh2, ((MethodHandle)mh2).form);
1681 throw newInternalError(msg);
1682 }
1683 }
1684
1685 // Local constant functions:
1686 /*non-public*/ static final NamedFunction
1687 NF_checkSpreadArgument,
1688 NF_guardWithCatch,
1689 NF_throwException,
1690 NF_tryFinally,
1691 NF_loop,
1692 NF_profileBoolean;
1693
1694 static {
1695 try {
1696 NF_checkSpreadArgument = new NamedFunction(MethodHandleImpl.class
1697 .getDeclaredMethod("checkSpreadArgument", Object.class, int.class));
1698 NF_guardWithCatch = new NamedFunction(MethodHandleImpl.class
1699 .getDeclaredMethod("guardWithCatch", MethodHandle.class, Class.class,
1700 MethodHandle.class, Object[].class));
1701 NF_tryFinally = new NamedFunction(MethodHandleImpl.class
1702 .getDeclaredMethod("tryFinally", MethodHandle.class, MethodHandle.class, Object[].class));
1703 NF_loop = new NamedFunction(MethodHandleImpl.class
1704 .getDeclaredMethod("loop", BasicType[].class, MethodHandle[].class, MethodHandle[].class,
1705 MethodHandle[].class, MethodHandle[].class, Object[].class));
1706 NF_throwException = new NamedFunction(MethodHandleImpl.class
1707 .getDeclaredMethod("throwException", Throwable.class));
1708 NF_profileBoolean = new NamedFunction(MethodHandleImpl.class
1709 .getDeclaredMethod("profileBoolean", boolean.class, int[].class));
1710 } catch (ReflectiveOperationException ex) {
1711 throw newInternalError(ex);
1712 }
1713 }
1714
1715 /** Result unboxing: ValueConversions.unbox() OR ValueConversions.identity() OR ValueConversions.ignore(). */
1716 private static MethodHandle unboxResultHandle(Class<?> returnType) {
1717 if (returnType.isPrimitive()) {
1718 if (returnType == void.class) {
1719 return ValueConversions.ignore();
1720 } else {
1721 Wrapper w = Wrapper.forPrimitiveType(returnType);
1722 return ValueConversions.unboxExact(w);
1723 }
1724 } else {
1725 return MethodHandles.identity(Object.class);
1726 }
1727 }
1728
1729 /**
1730 * Assembles a loop method handle from the given handles and type information.
1731 *
1732 * @param tloop the return type of the loop.
1733 * @param targs types of the arguments to be passed to the loop.
1734 * @param init sanitized array of initializers for loop-local variables.
1735 * @param step sanitited array of loop bodies.
1736 * @param pred sanitized array of predicates.
1737 * @param fini sanitized array of loop finalizers.
1738 *
1739 * @return a handle that, when invoked, will execute the loop.
1740 */
1741 static MethodHandle makeLoop(Class<?> tloop, List<Class<?>> targs, List<MethodHandle> init, List<MethodHandle> step,
1742 List<MethodHandle> pred, List<MethodHandle> fini) {
1743 MethodType type = MethodType.methodType(tloop, targs);
1744 BasicType[] initClauseTypes =
1745 init.stream().map(h -> h.type().returnType()).map(BasicType::basicType).toArray(BasicType[]::new);
1746 LambdaForm form = makeLoopForm(type.basicType(), initClauseTypes);
1747
1748 // Prepare auxiliary method handles used during LambdaForm interpretation.
1749 // Box arguments and wrap them into Object[]: ValueConversions.array().
1750 MethodType varargsType = type.changeReturnType(Object[].class);
1751 MethodHandle collectArgs = varargsArray(type.parameterCount()).asType(varargsType);
1752 MethodHandle unboxResult = unboxResultHandle(tloop);
1753
1754 BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_LLLLLL();
1755 BoundMethodHandle mh;
1756 try {
1757 mh = (BoundMethodHandle) data.constructor().invokeBasic(type, form, (Object) toArray(init),
1758 (Object) toArray(step), (Object) toArray(pred), (Object) toArray(fini), (Object) collectArgs,
1759 (Object) unboxResult);
1760 } catch (Throwable ex) {
1761 throw uncaughtException(ex);
1762 }
1763 assert(mh.type() == type);
1764 return mh;
1765 }
1766
1767 private static MethodHandle[] toArray(List<MethodHandle> l) {
1768 return l.toArray(new MethodHandle[0]);
1769 }
1770
1771 /**
1772 * Loops introduce some complexity as they can have additional local state. Hence, LambdaForms for loops are
1773 * generated from a template. The LambdaForm template shape for the loop combinator is as follows (assuming one
1774 * reference parameter passed in {@code a1}, and a reference return type, with the return value represented by
1775 * {@code t12}):
1776 * <blockquote><pre>{@code
1777 * loop=Lambda(a0:L,a1:L)=>{
1778 * t2:L=BoundMethodHandle$Species_L6.argL0(a0:L); // array of init method handles
1779 * t3:L=BoundMethodHandle$Species_L6.argL1(a0:L); // array of step method handles
1780 * t4:L=BoundMethodHandle$Species_L6.argL2(a0:L); // array of pred method handles
1781 * t5:L=BoundMethodHandle$Species_L6.argL3(a0:L); // array of fini method handles
1782 * t6:L=BoundMethodHandle$Species_L6.argL4(a0:L); // helper handle to box the arguments into an Object[]
1783 * t7:L=BoundMethodHandle$Species_L6.argL5(a0:L); // helper handle to unbox the result
1784 * t8:L=MethodHandle.invokeBasic(t6:L,a1:L); // box the arguments into an Object[]
1785 * t9:L=MethodHandleImpl.loop(null,t2:L,t3:L,t4:L,t5:L,t6:L); // call the loop executor
1786 * t10:L=MethodHandle.invokeBasic(t7:L,t9:L);t10:L} // unbox the result; return the result
1787 * }</pre></blockquote>
1788 * <p>
1789 * {@code argL0} through {@code argL3} are the arrays of init, step, pred, and fini method handles.
1790 * {@code argL4} and {@code argL5} are auxiliary method handles: {@code argL2} boxes arguments and wraps them into
1791 * {@code Object[]} ({@code ValueConversions.array()}), and {@code argL3} unboxes the result if necessary
1792 * ({@code ValueConversions.unbox()}).
1793 * <p>
1794 * Having {@code t6} and {@code t7} passed in via a BMH and not hardcoded in the lambda form allows to share lambda
1795 * forms among loop combinators with the same basic type.
1796 * <p>
1797 * The above template is instantiated by using the {@link LambdaFormEditor} to replace the {@code null} argument to
1798 * the {@code loop} invocation with the {@code BasicType} array describing the loop clause types. This argument is
1799 * ignored in the loop invoker, but will be extracted and used in {@linkplain InvokerBytecodeGenerator#emitLoop(int)
1800 * bytecode generation}.
1801 */
1802 private static LambdaForm makeLoopForm(MethodType basicType, BasicType[] localVarTypes) {
1803 MethodType lambdaType = basicType.invokerType();
1804
1805 final int THIS_MH = 0; // the BMH_LLLLLL
1806 final int ARG_BASE = 1; // start of incoming arguments
1807 final int ARG_LIMIT = ARG_BASE + basicType.parameterCount();
1808
1809 int nameCursor = ARG_LIMIT;
1810 final int GET_INITS = nameCursor++;
1811 final int GET_STEPS = nameCursor++;
1812 final int GET_PREDS = nameCursor++;
1813 final int GET_FINIS = nameCursor++;
1814 final int GET_COLLECT_ARGS = nameCursor++;
1815 final int GET_UNBOX_RESULT = nameCursor++;
1816 final int BOXED_ARGS = nameCursor++;
1817 final int LOOP = nameCursor++;
1818 final int UNBOX_RESULT = nameCursor++;
1819
1820 LambdaForm lform = basicType.form().cachedLambdaForm(MethodTypeForm.LF_LOOP);
1821 if (lform == null) {
1822 Name[] names = arguments(nameCursor - ARG_LIMIT, lambdaType);
1823
1824 BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_LLLLLL();
1825 names[THIS_MH] = names[THIS_MH].withConstraint(data);
1826 names[GET_INITS] = new Name(data.getterFunction(0), names[THIS_MH]);
1827 names[GET_STEPS] = new Name(data.getterFunction(1), names[THIS_MH]);
1828 names[GET_PREDS] = new Name(data.getterFunction(2), names[THIS_MH]);
1829 names[GET_FINIS] = new Name(data.getterFunction(3), names[THIS_MH]);
1830 names[GET_COLLECT_ARGS] = new Name(data.getterFunction(4), names[THIS_MH]);
1831 names[GET_UNBOX_RESULT] = new Name(data.getterFunction(5), names[THIS_MH]);
1832
1833 // t_{i}:L=MethodHandle.invokeBasic(collectArgs:L,a1:L,...);
1834 MethodType collectArgsType = basicType.changeReturnType(Object.class);
1835 MethodHandle invokeBasic = MethodHandles.basicInvoker(collectArgsType);
1836 Object[] args = new Object[invokeBasic.type().parameterCount()];
1837 args[0] = names[GET_COLLECT_ARGS];
1838 System.arraycopy(names, ARG_BASE, args, 1, ARG_LIMIT - ARG_BASE);
1839 names[BOXED_ARGS] = new Name(makeIntrinsic(invokeBasic, Intrinsic.LOOP), args);
1840
1841 // t_{i+1}:L=MethodHandleImpl.loop(localTypes:L,inits:L,steps:L,preds:L,finis:L,t_{i}:L);
1842 Object[] lArgs =
1843 new Object[]{null, // placeholder for BasicType[] localTypes - will be added by LambdaFormEditor
1844 names[GET_INITS], names[GET_STEPS], names[GET_PREDS], names[GET_FINIS], names[BOXED_ARGS]};
1845 names[LOOP] = new Name(NF_loop, lArgs);
1846
1847 // t_{i+2}:I=MethodHandle.invokeBasic(unbox:L,t_{i+1}:L);
1848 MethodHandle invokeBasicUnbox = MethodHandles.basicInvoker(MethodType.methodType(basicType.rtype(), Object.class));
1849 Object[] unboxArgs = new Object[]{names[GET_UNBOX_RESULT], names[LOOP]};
1850 names[UNBOX_RESULT] = new Name(invokeBasicUnbox, unboxArgs);
1851
1852 lform = basicType.form().setCachedLambdaForm(MethodTypeForm.LF_LOOP,
1853 new LambdaForm("loop", lambdaType.parameterCount(), names));
1854 }
1855
1856 // BOXED_ARGS is the index into the names array where the loop idiom starts
1857 return lform.editor().noteLoopLocalTypesForm(BOXED_ARGS, localVarTypes);
1858 }
1859
1860
1861 /**
1862 * Intrinsified during LambdaForm compilation
1863 * (see {@link InvokerBytecodeGenerator#emitLoop(int)}).
1864 */
1865 @LambdaForm.Hidden
1866 static Object loop(BasicType[] localTypes, MethodHandle[] init, MethodHandle[] step, MethodHandle[] pred,
1867 MethodHandle[] fini, Object... av) throws Throwable {
1868 int varSize = (int) Stream.of(init).filter(h -> h.type().returnType() != void.class).count();
1869 int nArgs = init[0].type().parameterCount();
1870 Object[] varsAndArgs = new Object[varSize + nArgs];
1871 for (int i = 0, v = 0; i < init.length; ++i) {
1872 if (init[i].type().returnType() == void.class) {
1873 init[i].asFixedArity().invokeWithArguments(av);
1874 } else {
1875 varsAndArgs[v++] = init[i].asFixedArity().invokeWithArguments(av);
1876 }
1877 }
1878 System.arraycopy(av, 0, varsAndArgs, varSize, nArgs);
1879 final int nSteps = step.length;
1880 for (; ; ) {
1881 for (int i = 0, v = 0; i < nSteps; ++i) {
1882 MethodHandle p = pred[i];
1883 MethodHandle s = step[i];
1884 MethodHandle f = fini[i];
1885 if (s.type().returnType() == void.class) {
1886 s.asFixedArity().invokeWithArguments(varsAndArgs);
1887 } else {
1888 varsAndArgs[v++] = s.asFixedArity().invokeWithArguments(varsAndArgs);
1889 }
1890 if (!(boolean) p.asFixedArity().invokeWithArguments(varsAndArgs)) {
1891 return f.asFixedArity().invokeWithArguments(varsAndArgs);
1892 }
1893 }
1894 }
1895 }
1896
1897 /**
1898 * This method is bound as the predicate in {@linkplain MethodHandles#countedLoop(MethodHandle, MethodHandle,
1899 * MethodHandle) counting loops}.
1900 *
1901 * @param counter the counter parameter, passed in during loop execution.
1902 * @param limit the upper bound of the parameter, statically bound at loop creation time.
1903 *
1904 * @return whether the counter has reached the limit.
1905 */
1906 static boolean countedLoopPredicate(int counter, int limit) {
1907 return counter <= limit;
1908 }
1909
1910 /**
1911 * This method is bound as the step function in {@linkplain MethodHandles#countedLoop(MethodHandle, MethodHandle,
1912 * MethodHandle) counting loops} to increment the counter.
1913 *
1914 * @param counter the loop counter.
1915 *
1916 * @return the loop counter incremented by 1.
1917 */
1918 static int countedLoopStep(int counter, int limit) {
1919 return counter + 1;
1920 }
1921
1922 /**
1923 * This method is bound as a filter in {@linkplain MethodHandles#countedLoop(MethodHandle, MethodHandle, MethodHandle,
1924 * MethodHandle) counting loops} to pass the correct counter value to the body.
1925 *
1926 * @param counter the loop counter.
1927 *
1928 * @return the loop counter decremented by 1.
1929 */
1930 static int decrementCounter(int counter) {
1931 return counter - 1;
1932 }
1933
1934 /**
1935 * This is bound to initialize the loop-local iterator in {@linkplain MethodHandles#iteratedLoop iterating loops}.
1936 *
1937 * @param it the {@link Iterable} over which the loop iterates.
1938 *
1939 * @return an {@link Iterator} over the argument's elements.
1940 */
1941 static Iterator<?> initIterator(Iterable<?> it) {
1942 return it.iterator();
1943 }
1944
1945 /**
1946 * This method is bound as the predicate in {@linkplain MethodHandles#iteratedLoop iterating loops}.
1947 *
1948 * @param it the iterator to be checked.
1949 *
1950 * @return {@code true} iff there are more elements to iterate over.
1951 */
1952 static boolean iteratePredicate(Iterator<?> it) {
1953 return it.hasNext();
1954 }
1955
1956 /**
1957 * This method is bound as the step for retrieving the current value from the iterator in {@linkplain
1958 * MethodHandles#iteratedLoop iterating loops}.
1959 *
1960 * @param it the iterator.
1961 *
1962 * @return the next element from the iterator.
1963 */
1964 static Object iterateNext(Iterator<?> it) {
1965 return it.next();
1966 }
1967
1968 /**
1969 * Makes a {@code try-finally} handle that conforms to the type constraints.
1970 *
1971 * @param target the target to execute in a {@code try-finally} block.
1972 * @param cleanup the cleanup to execute in the {@code finally} block.
1973 * @param rtype the result type of the entire construct.
1974 * @param argTypes the types of the arguments.
1975 *
1976 * @return a handle on the constructed {@code try-finally} block.
1977 */
1978 static MethodHandle makeTryFinally(MethodHandle target, MethodHandle cleanup, Class<?> rtype, List<Class<?>> argTypes) {
1979 MethodType type = MethodType.methodType(rtype, argTypes);
1980 LambdaForm form = makeTryFinallyForm(type.basicType());
1981
1982 // Prepare auxiliary method handles used during LambdaForm interpretation.
1983 // Box arguments and wrap them into Object[]: ValueConversions.array().
1984 MethodType varargsType = type.changeReturnType(Object[].class);
1985 MethodHandle collectArgs = varargsArray(type.parameterCount()).asType(varargsType);
1986 MethodHandle unboxResult = unboxResultHandle(rtype);
1987
1988 BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_LLLL();
1989 BoundMethodHandle mh;
1990 try {
1991 mh = (BoundMethodHandle) data.constructor().invokeBasic(type, form, (Object) target, (Object) cleanup,
1992 (Object) collectArgs, (Object) unboxResult);
1993 } catch (Throwable ex) {
1994 throw uncaughtException(ex);
1995 }
1996 assert(mh.type() == type);
1997 return mh;
1998 }
1999
2000 /**
2001 * The LambdaForm shape for the tryFinally combinator is as follows (assuming one reference parameter passed in
2002 * {@code a1}, and a reference return type, with the return value represented by {@code t8}):
2003 * <blockquote><pre>{@code
2004 * tryFinally=Lambda(a0:L,a1:L)=>{
2005 * t2:L=BoundMethodHandle$Species_LLLL.argL0(a0:L); // target method handle
2006 * t3:L=BoundMethodHandle$Species_LLLL.argL1(a0:L); // cleanup method handle
2007 * t4:L=BoundMethodHandle$Species_LLLL.argL2(a0:L); // helper handle to box the arguments into an Object[]
2008 * t5:L=BoundMethodHandle$Species_LLLL.argL3(a0:L); // helper handle to unbox the result
2009 * t6:L=MethodHandle.invokeBasic(t4:L,a1:L); // box the arguments into an Object[]
2010 * t7:L=MethodHandleImpl.tryFinally(t2:L,t3:L,t6:L); // call the tryFinally executor
2011 * t8:L=MethodHandle.invokeBasic(t5:L,t7:L);t8:L} // unbox the result; return the result
2012 * }</pre></blockquote>
2013 * <p>
2014 * {@code argL0} and {@code argL1} are the target and cleanup method handles.
2015 * {@code argL2} and {@code argL3} are auxiliary method handles: {@code argL2} boxes arguments and wraps them into
2016 * {@code Object[]} ({@code ValueConversions.array()}), and {@code argL3} unboxes the result if necessary
2017 * ({@code ValueConversions.unbox()}).
2018 * <p>
2019 * Having {@code t4} and {@code t5} passed in via a BMH and not hardcoded in the lambda form allows to share lambda
2020 * forms among tryFinally combinators with the same basic type.
2021 */
2022 private static LambdaForm makeTryFinallyForm(MethodType basicType) {
2023 MethodType lambdaType = basicType.invokerType();
2024
2025 LambdaForm lform = basicType.form().cachedLambdaForm(MethodTypeForm.LF_TF);
2026 if (lform != null) {
2027 return lform;
2028 }
2029 final int THIS_MH = 0; // the BMH_LLLL
2030 final int ARG_BASE = 1; // start of incoming arguments
2031 final int ARG_LIMIT = ARG_BASE + basicType.parameterCount();
2032
2033 int nameCursor = ARG_LIMIT;
2034 final int GET_TARGET = nameCursor++;
2035 final int GET_CLEANUP = nameCursor++;
2036 final int GET_COLLECT_ARGS = nameCursor++;
2037 final int GET_UNBOX_RESULT = nameCursor++;
2038 final int BOXED_ARGS = nameCursor++;
2039 final int TRY_FINALLY = nameCursor++;
2040 final int UNBOX_RESULT = nameCursor++;
2041
2042 Name[] names = arguments(nameCursor - ARG_LIMIT, lambdaType);
2043
2044 BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_LLLL();
2045 names[THIS_MH] = names[THIS_MH].withConstraint(data);
2046 names[GET_TARGET] = new Name(data.getterFunction(0), names[THIS_MH]);
2047 names[GET_CLEANUP] = new Name(data.getterFunction(1), names[THIS_MH]);
2048 names[GET_COLLECT_ARGS] = new Name(data.getterFunction(2), names[THIS_MH]);
2049 names[GET_UNBOX_RESULT] = new Name(data.getterFunction(3), names[THIS_MH]);
2050
2051 // t_{i}:L=MethodHandle.invokeBasic(collectArgs:L,a1:L,...);
2052 MethodType collectArgsType = basicType.changeReturnType(Object.class);
2053 MethodHandle invokeBasic = MethodHandles.basicInvoker(collectArgsType);
2054 Object[] args = new Object[invokeBasic.type().parameterCount()];
2055 args[0] = names[GET_COLLECT_ARGS];
2056 System.arraycopy(names, ARG_BASE, args, 1, ARG_LIMIT-ARG_BASE);
2057 names[BOXED_ARGS] = new Name(makeIntrinsic(invokeBasic, Intrinsic.TRY_FINALLY), args);
2058
2059 // t_{i+1}:L=MethodHandleImpl.tryFinally(target:L,exType:L,catcher:L,t_{i}:L);
2060 Object[] tfArgs = new Object[] {names[GET_TARGET], names[GET_CLEANUP], names[BOXED_ARGS]};
2061 names[TRY_FINALLY] = new Name(NF_tryFinally, tfArgs);
2062
2063 // t_{i+2}:I=MethodHandle.invokeBasic(unbox:L,t_{i+1}:L);
2064 MethodHandle invokeBasicUnbox = MethodHandles.basicInvoker(MethodType.methodType(basicType.rtype(), Object.class));
2065 Object[] unboxArgs = new Object[] {names[GET_UNBOX_RESULT], names[TRY_FINALLY]};
2066 names[UNBOX_RESULT] = new Name(invokeBasicUnbox, unboxArgs);
2067
2068 lform = new LambdaForm("tryFinally", lambdaType.parameterCount(), names);
2069
2070 return basicType.form().setCachedLambdaForm(MethodTypeForm.LF_TF, lform);
2071 }
2072
2073 /**
2074 * Intrinsified during LambdaForm compilation
2075 * (see {@link InvokerBytecodeGenerator#emitTryFinally emitTryFinally}).
2076 */
2077 @LambdaForm.Hidden
2078 static Object tryFinally(MethodHandle target, MethodHandle cleanup, Object... av) throws Throwable {
2079 Throwable t = null;
2080 Object r = null;
2081 try {
2082 // Use asFixedArity() to avoid unnecessary boxing of last argument for VarargsCollector case.
2083 r = target.asFixedArity().invokeWithArguments(av);
2084 } catch (Throwable thrown) {
2085 t = thrown;
2086 throw t;
2087 } finally {
2088 Object[] args = target.type().returnType() == void.class ? prepend(av, t) : prepend(av, t, r);
2089 r = cleanup.asFixedArity().invokeWithArguments(args);
2090 }
2091 return r;
2092 }
2093
2094 // Indexes into constant method handles:
2095 static final int
2096 MH_cast = 0,
2097 MH_selectAlternative = 1,
2098 MH_copyAsPrimitiveArray = 2,
2099 MH_fillNewTypedArray = 3,
2100 MH_fillNewArray = 4,
2101 MH_arrayIdentity = 5,
2102 MH_countedLoopPred = 6,
2103 MH_countedLoopStep = 7,
2104 MH_iteratePred = 8,
2105 MH_initIterator = 9,
2106 MH_iterateNext = 10,
2107 MH_decrementCounter = 11,
2108 MH_Array_newInstance = 12,
2109 MH_LIMIT = 13;
2110
2111 static MethodHandle getConstantHandle(int idx) {
2112 MethodHandle handle = HANDLES[idx];
2113 if (handle != null) {
2114 return handle;
2115 }
2116 return setCachedHandle(idx, makeConstantHandle(idx));
2117 }
2118
2119 private static synchronized MethodHandle setCachedHandle(int idx, final MethodHandle method) {
2120 // Simulate a CAS, to avoid racy duplication of results.
2121 MethodHandle prev = HANDLES[idx];
2122 if (prev != null) {
2123 return prev;
2124 }
2125 HANDLES[idx] = method;
2126 return method;
2127 }
2128
2129 // Local constant method handles:
2130 private static final @Stable MethodHandle[] HANDLES = new MethodHandle[MH_LIMIT];
2131
2132 private static MethodHandle makeConstantHandle(int idx) {
2133 try {
2134 switch (idx) {
2135 case MH_cast:
2136 return IMPL_LOOKUP.findVirtual(Class.class, "cast",
2137 MethodType.methodType(Object.class, Object.class));
2138 case MH_copyAsPrimitiveArray:
2139 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "copyAsPrimitiveArray",
2140 MethodType.methodType(Object.class, Wrapper.class, Object[].class));
2141 case MH_arrayIdentity:
2142 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "identity",
2143 MethodType.methodType(Object[].class, Object[].class));
2144 case MH_fillNewArray:
2145 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "fillNewArray",
2146 MethodType.methodType(Object[].class, Integer.class, Object[].class));
2147 case MH_fillNewTypedArray:
2148 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "fillNewTypedArray",
2149 MethodType.methodType(Object[].class, Object[].class, Integer.class, Object[].class));
2150 case MH_selectAlternative:
2151 return makeIntrinsic(IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "selectAlternative",
2152 MethodType.methodType(MethodHandle.class, boolean.class, MethodHandle.class, MethodHandle.class)),
2153 Intrinsic.SELECT_ALTERNATIVE);
2154 case MH_countedLoopPred:
2155 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "countedLoopPredicate",
2156 MethodType.methodType(boolean.class, int.class, int.class));
2157 case MH_countedLoopStep:
2158 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "countedLoopStep",
2159 MethodType.methodType(int.class, int.class, int.class));
2160 case MH_iteratePred:
2161 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "iteratePredicate",
2162 MethodType.methodType(boolean.class, Iterator.class));
2163 case MH_initIterator:
2164 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "initIterator",
2165 MethodType.methodType(Iterator.class, Iterable.class));
2166 case MH_iterateNext:
2167 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "iterateNext",
2168 MethodType.methodType(Object.class, Iterator.class));
2169 case MH_decrementCounter:
2170 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "decrementCounter",
2171 MethodType.methodType(int.class, int.class));
2172 case MH_Array_newInstance:
2173 return IMPL_LOOKUP.findStatic(Array.class, "newInstance",
2174 MethodType.methodType(Object.class, Class.class, int.class));
2175 }
2176 } catch (ReflectiveOperationException ex) {
2177 throw newInternalError(ex);
2178 }
2179 throw newInternalError("Unknown function index: " + idx);
2180 }
2181 }