1 /*
2 * Copyright (c) 2008, 2023, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package java.lang.invoke;
27
28 import jdk.internal.access.JavaLangInvokeAccess;
29 import jdk.internal.access.SharedSecrets;
30 import jdk.internal.constant.MethodTypeDescImpl;
31 import jdk.internal.constant.ReferenceClassDescImpl;
32 import jdk.internal.foreign.abi.NativeEntryPoint;
33 import jdk.internal.reflect.CallerSensitive;
34 import jdk.internal.reflect.Reflection;
35 import jdk.internal.vm.annotation.ForceInline;
36 import jdk.internal.vm.annotation.Hidden;
37 import jdk.internal.vm.annotation.Stable;
38 import sun.invoke.empty.Empty;
39 import sun.invoke.util.ValueConversions;
40 import sun.invoke.util.VerifyType;
41 import sun.invoke.util.Wrapper;
42
43 import java.lang.classfile.ClassFile;
44 import java.lang.constant.ClassDesc;
45 import java.lang.invoke.MethodHandles.Lookup;
46 import java.lang.reflect.Array;
47 import java.lang.reflect.Constructor;
48 import java.lang.reflect.Field;
49 import java.nio.ByteOrder;
50 import java.util.Arrays;
51 import java.util.Collections;
52 import java.util.HashMap;
53 import java.util.Iterator;
54 import java.util.List;
55 import java.util.Map;
56 import java.util.Objects;
57 import java.util.Set;
58 import java.util.concurrent.ConcurrentHashMap;
59 import java.util.function.Function;
60 import java.util.stream.Stream;
61
62 import static java.lang.classfile.ClassFile.*;
63 import static java.lang.constant.ConstantDescs.*;
64 import static java.lang.invoke.LambdaForm.*;
65 import static java.lang.invoke.MethodHandleNatives.Constants.MN_CALLER_SENSITIVE;
66 import static java.lang.invoke.MethodHandleNatives.Constants.MN_HIDDEN_MEMBER;
67 import static java.lang.invoke.MethodHandleNatives.Constants.NESTMATE_CLASS;
68 import static java.lang.invoke.MethodHandleStatics.*;
69 import static java.lang.invoke.MethodHandles.Lookup.IMPL_LOOKUP;
70 import static java.lang.invoke.MethodHandles.Lookup.ClassOption.NESTMATE;
71
72 /**
73 * Trusted implementation code for MethodHandle.
74 * @author jrose
75 */
76 /*non-public*/
77 abstract class MethodHandleImpl {
78
79 /// Factory methods to create method handles:
80
81 static MethodHandle makeArrayElementAccessor(Class<?> arrayClass, ArrayAccess access) {
82 if (arrayClass == Object[].class) {
83 return ArrayAccess.objectAccessor(access);
84 }
85 if (!arrayClass.isArray())
86 throw newIllegalArgumentException("not an array: "+arrayClass);
87 MethodHandle[] cache = ArrayAccessor.TYPED_ACCESSORS.get(arrayClass);
88 int cacheIndex = ArrayAccess.cacheIndex(access);
89 MethodHandle mh = cache[cacheIndex];
90 if (mh != null) return mh;
91 mh = ArrayAccessor.getAccessor(arrayClass, access);
92 MethodType correctType = ArrayAccessor.correctType(arrayClass, access);
93 if (mh.type() != correctType) {
94 assert(mh.type().parameterType(0) == Object[].class);
95 /* if access == SET */ assert(access != ArrayAccess.SET || mh.type().parameterType(2) == Object.class);
96 /* if access == GET */ assert(access != ArrayAccess.GET ||
97 (mh.type().returnType() == Object.class &&
98 correctType.parameterType(0).getComponentType() == correctType.returnType()));
99 // safe to view non-strictly, because element type follows from array type
100 mh = mh.viewAsType(correctType, false);
101 }
102 mh = makeIntrinsic(mh, ArrayAccess.intrinsic(access));
103 // Atomically update accessor cache.
104 synchronized(cache) {
105 if (cache[cacheIndex] == null) {
106 cache[cacheIndex] = mh;
107 } else {
108 // Throw away newly constructed accessor and use cached version.
109 mh = cache[cacheIndex];
110 }
111 }
112 return mh;
113 }
114
115 enum ArrayAccess {
116 GET, SET, LENGTH;
117
118 // As ArrayAccess and ArrayAccessor have a circular dependency, the ArrayAccess properties cannot be stored in
119 // final fields.
120
121 static String opName(ArrayAccess a) {
122 return switch (a) {
123 case GET -> "getElement";
124 case SET -> "setElement";
125 case LENGTH -> "length";
126 default -> throw unmatchedArrayAccess(a);
127 };
128 }
129
130 static MethodHandle objectAccessor(ArrayAccess a) {
131 return switch (a) {
132 case GET -> ArrayAccessor.OBJECT_ARRAY_GETTER;
133 case SET -> ArrayAccessor.OBJECT_ARRAY_SETTER;
134 case LENGTH -> ArrayAccessor.OBJECT_ARRAY_LENGTH;
135 default -> throw unmatchedArrayAccess(a);
136 };
137 }
138
139 static int cacheIndex(ArrayAccess a) {
140 return switch (a) {
141 case GET -> ArrayAccessor.GETTER_INDEX;
142 case SET -> ArrayAccessor.SETTER_INDEX;
143 case LENGTH -> ArrayAccessor.LENGTH_INDEX;
144 default -> throw unmatchedArrayAccess(a);
145 };
146 }
147
148 static Intrinsic intrinsic(ArrayAccess a) {
149 return switch (a) {
150 case GET -> Intrinsic.ARRAY_LOAD;
151 case SET -> Intrinsic.ARRAY_STORE;
152 case LENGTH -> Intrinsic.ARRAY_LENGTH;
153 default -> throw unmatchedArrayAccess(a);
154 };
155 }
156 }
157
158 static InternalError unmatchedArrayAccess(ArrayAccess a) {
159 return newInternalError("should not reach here (unmatched ArrayAccess: " + a + ")");
160 }
161
162 static final class ArrayAccessor {
163 /// Support for array element and length access
164 static final int GETTER_INDEX = 0, SETTER_INDEX = 1, LENGTH_INDEX = 2, INDEX_LIMIT = 3;
165 static final ClassValue<MethodHandle[]> TYPED_ACCESSORS
166 = new ClassValue<MethodHandle[]>() {
167 @Override
168 protected MethodHandle[] computeValue(Class<?> type) {
169 return new MethodHandle[INDEX_LIMIT];
170 }
171 };
172 static final MethodHandle OBJECT_ARRAY_GETTER, OBJECT_ARRAY_SETTER, OBJECT_ARRAY_LENGTH;
173 static {
174 MethodHandle[] cache = TYPED_ACCESSORS.get(Object[].class);
175 cache[GETTER_INDEX] = OBJECT_ARRAY_GETTER = makeIntrinsic(getAccessor(Object[].class, ArrayAccess.GET), Intrinsic.ARRAY_LOAD);
176 cache[SETTER_INDEX] = OBJECT_ARRAY_SETTER = makeIntrinsic(getAccessor(Object[].class, ArrayAccess.SET), Intrinsic.ARRAY_STORE);
177 cache[LENGTH_INDEX] = OBJECT_ARRAY_LENGTH = makeIntrinsic(getAccessor(Object[].class, ArrayAccess.LENGTH), Intrinsic.ARRAY_LENGTH);
178
179 assert(InvokerBytecodeGenerator.isStaticallyInvocable(ArrayAccessor.OBJECT_ARRAY_GETTER.internalMemberName()));
180 assert(InvokerBytecodeGenerator.isStaticallyInvocable(ArrayAccessor.OBJECT_ARRAY_SETTER.internalMemberName()));
181 assert(InvokerBytecodeGenerator.isStaticallyInvocable(ArrayAccessor.OBJECT_ARRAY_LENGTH.internalMemberName()));
182 }
183
184 static int getElementI(int[] a, int i) { return a[i]; }
185 static long getElementJ(long[] a, int i) { return a[i]; }
186 static float getElementF(float[] a, int i) { return a[i]; }
187 static double getElementD(double[] a, int i) { return a[i]; }
188 static boolean getElementZ(boolean[] a, int i) { return a[i]; }
189 static byte getElementB(byte[] a, int i) { return a[i]; }
190 static short getElementS(short[] a, int i) { return a[i]; }
191 static char getElementC(char[] a, int i) { return a[i]; }
192 static Object getElementL(Object[] a, int i) { return a[i]; }
193
194 static void setElementI(int[] a, int i, int x) { a[i] = x; }
195 static void setElementJ(long[] a, int i, long x) { a[i] = x; }
196 static void setElementF(float[] a, int i, float x) { a[i] = x; }
197 static void setElementD(double[] a, int i, double x) { a[i] = x; }
198 static void setElementZ(boolean[] a, int i, boolean x) { a[i] = x; }
199 static void setElementB(byte[] a, int i, byte x) { a[i] = x; }
200 static void setElementS(short[] a, int i, short x) { a[i] = x; }
201 static void setElementC(char[] a, int i, char x) { a[i] = x; }
202 static void setElementL(Object[] a, int i, Object x) { a[i] = x; }
203
204 static int lengthI(int[] a) { return a.length; }
205 static int lengthJ(long[] a) { return a.length; }
206 static int lengthF(float[] a) { return a.length; }
207 static int lengthD(double[] a) { return a.length; }
208 static int lengthZ(boolean[] a) { return a.length; }
209 static int lengthB(byte[] a) { return a.length; }
210 static int lengthS(short[] a) { return a.length; }
211 static int lengthC(char[] a) { return a.length; }
212 static int lengthL(Object[] a) { return a.length; }
213
214 static String name(Class<?> arrayClass, ArrayAccess access) {
215 Class<?> elemClass = arrayClass.getComponentType();
216 if (elemClass == null) throw newIllegalArgumentException("not an array", arrayClass);
217 return ArrayAccess.opName(access) + Wrapper.basicTypeChar(elemClass);
218 }
219 static MethodType type(Class<?> arrayClass, ArrayAccess access) {
220 Class<?> elemClass = arrayClass.getComponentType();
221 Class<?> arrayArgClass = arrayClass;
222 if (!elemClass.isPrimitive()) {
223 arrayArgClass = Object[].class;
224 elemClass = Object.class;
225 }
226 return switch (access) {
227 case GET -> MethodType.methodType(elemClass, arrayArgClass, int.class);
228 case SET -> MethodType.methodType(void.class, arrayArgClass, int.class, elemClass);
229 case LENGTH -> MethodType.methodType(int.class, arrayArgClass);
230 default -> throw unmatchedArrayAccess(access);
231 };
232 }
233 static MethodType correctType(Class<?> arrayClass, ArrayAccess access) {
234 Class<?> elemClass = arrayClass.getComponentType();
235 return switch (access) {
236 case GET -> MethodType.methodType(elemClass, arrayClass, int.class);
237 case SET -> MethodType.methodType(void.class, arrayClass, int.class, elemClass);
238 case LENGTH -> MethodType.methodType(int.class, arrayClass);
239 default -> throw unmatchedArrayAccess(access);
240 };
241 }
242 static MethodHandle getAccessor(Class<?> arrayClass, ArrayAccess access) {
243 String name = name(arrayClass, access);
244 MethodType type = type(arrayClass, access);
245 try {
246 return IMPL_LOOKUP.findStatic(ArrayAccessor.class, name, type);
247 } catch (ReflectiveOperationException ex) {
248 throw uncaughtException(ex);
249 }
250 }
251 }
252
253 /**
254 * Create a JVM-level adapter method handle to conform the given method
255 * handle to the similar newType, using only pairwise argument conversions.
256 * For each argument, convert incoming argument to the exact type needed.
257 * The argument conversions allowed are casting, boxing and unboxing,
258 * integral widening or narrowing, and floating point widening or narrowing.
259 * @param srcType required call type
260 * @param target original method handle
261 * @param strict if true, only asType conversions are allowed; if false, explicitCastArguments conversions allowed
262 * @param monobox if true, unboxing conversions are assumed to be exactly typed (Integer to int only, not long or double)
263 * @return an adapter to the original handle with the desired new type,
264 * or the original target if the types are already identical
265 * or null if the adaptation cannot be made
266 */
267 static MethodHandle makePairwiseConvert(MethodHandle target, MethodType srcType,
268 boolean strict, boolean monobox) {
269 MethodType dstType = target.type();
270 if (srcType == dstType)
271 return target;
272 return makePairwiseConvertByEditor(target, srcType, strict, monobox);
273 }
274
275 private static int countNonNull(Object[] array) {
276 int count = 0;
277 if (array != null) {
278 for (Object x : array) {
279 if (x != null) ++count;
280 }
281 }
282 return count;
283 }
284
285 static MethodHandle makePairwiseConvertByEditor(MethodHandle target, MethodType srcType,
286 boolean strict, boolean monobox) {
287 // In method types arguments start at index 0, while the LF
288 // editor have the MH receiver at position 0 - adjust appropriately.
289 final int MH_RECEIVER_OFFSET = 1;
290 Object[] convSpecs = computeValueConversions(srcType, target.type(), strict, monobox);
291 int convCount = countNonNull(convSpecs);
292 if (convCount == 0)
293 return target.viewAsType(srcType, strict);
294 MethodType basicSrcType = srcType.basicType();
295 MethodType midType = target.type().basicType();
296 BoundMethodHandle mh = target.rebind();
297
298 // Match each unique conversion to the positions at which it is to be applied
299 HashMap<Object, int[]> convSpecMap = HashMap.newHashMap(convCount);
300 for (int i = 0; i < convSpecs.length - MH_RECEIVER_OFFSET; i++) {
301 Object convSpec = convSpecs[i];
302 if (convSpec == null) continue;
303 int[] positions = convSpecMap.get(convSpec);
304 if (positions == null) {
305 positions = new int[] { i + MH_RECEIVER_OFFSET };
306 } else {
307 positions = Arrays.copyOf(positions, positions.length + 1);
308 positions[positions.length - 1] = i + MH_RECEIVER_OFFSET;
309 }
310 convSpecMap.put(convSpec, positions);
311 }
312 for (var entry : convSpecMap.entrySet()) {
313 Object convSpec = entry.getKey();
314
315 MethodHandle fn;
316 if (convSpec instanceof Class) {
317 fn = getConstantHandle(MH_cast).bindTo(convSpec);
318 } else {
319 fn = (MethodHandle) convSpec;
320 }
321 int[] positions = entry.getValue();
322 Class<?> newType = basicSrcType.parameterType(positions[0] - MH_RECEIVER_OFFSET);
323 BasicType newBasicType = BasicType.basicType(newType);
324 convCount -= positions.length;
325 if (convCount == 0) {
326 midType = srcType;
327 } else {
328 Class<?>[] ptypes = midType.ptypes().clone();
329 for (int pos : positions) {
330 ptypes[pos - 1] = newType;
331 }
332 midType = MethodType.methodType(midType.rtype(), ptypes, true);
333 }
334 LambdaForm form2;
335 if (positions.length > 1) {
336 form2 = mh.editor().filterRepeatedArgumentForm(newBasicType, positions);
337 } else {
338 form2 = mh.editor().filterArgumentForm(positions[0], newBasicType);
339 }
340 mh = mh.copyWithExtendL(midType, form2, fn);
341 }
342 Object convSpec = convSpecs[convSpecs.length - 1];
343 if (convSpec != null) {
344 MethodHandle fn;
345 if (convSpec instanceof Class) {
346 if (convSpec == void.class)
347 fn = null;
348 else
349 fn = getConstantHandle(MH_cast).bindTo(convSpec);
350 } else {
351 fn = (MethodHandle) convSpec;
352 }
353 Class<?> newType = basicSrcType.returnType();
354 assert(--convCount == 0);
355 midType = srcType;
356 if (fn != null) {
357 mh = mh.rebind(); // rebind if too complex
358 LambdaForm form2 = mh.editor().filterReturnForm(BasicType.basicType(newType), false);
359 mh = mh.copyWithExtendL(midType, form2, fn);
360 } else {
361 LambdaForm form2 = mh.editor().filterReturnForm(BasicType.basicType(newType), true);
362 mh = mh.copyWith(midType, form2);
363 }
364 }
365 assert(convCount == 0);
366 assert(mh.type().equals(srcType));
367 return mh;
368 }
369
370 static Object[] computeValueConversions(MethodType srcType, MethodType dstType,
371 boolean strict, boolean monobox) {
372 final int INARG_COUNT = srcType.parameterCount();
373 Object[] convSpecs = null;
374 for (int i = 0; i <= INARG_COUNT; i++) {
375 boolean isRet = (i == INARG_COUNT);
376 Class<?> src = isRet ? dstType.returnType() : srcType.parameterType(i);
377 Class<?> dst = isRet ? srcType.returnType() : dstType.parameterType(i);
378 if (!VerifyType.isNullConversion(src, dst, /*keepInterfaces=*/ strict)) {
379 if (convSpecs == null) {
380 convSpecs = new Object[INARG_COUNT + 1];
381 }
382 convSpecs[i] = valueConversion(src, dst, strict, monobox);
383 }
384 }
385 return convSpecs;
386 }
387 static MethodHandle makePairwiseConvert(MethodHandle target, MethodType srcType,
388 boolean strict) {
389 return makePairwiseConvert(target, srcType, strict, /*monobox=*/ false);
390 }
391
392 /**
393 * Find a conversion function from the given source to the given destination.
394 * This conversion function will be used as a LF NamedFunction.
395 * Return a Class object if a simple cast is needed.
396 * Return void.class if void is involved.
397 */
398 static Object valueConversion(Class<?> src, Class<?> dst, boolean strict, boolean monobox) {
399 assert(!VerifyType.isNullConversion(src, dst, /*keepInterfaces=*/ strict)); // caller responsibility
400 if (dst == void.class)
401 return dst;
402 MethodHandle fn;
403 if (src.isPrimitive()) {
404 if (src == void.class) {
405 return void.class; // caller must recognize this specially
406 } else if (dst.isPrimitive()) {
407 // Examples: int->byte, byte->int, boolean->int (!strict)
408 fn = ValueConversions.convertPrimitive(src, dst);
409 } else {
410 // Examples: int->Integer, boolean->Object, float->Number
411 Wrapper wsrc = Wrapper.forPrimitiveType(src);
412 fn = ValueConversions.boxExact(wsrc);
413 assert(fn.type().parameterType(0) == wsrc.primitiveType());
414 assert(fn.type().returnType() == wsrc.wrapperType());
415 if (!VerifyType.isNullConversion(wsrc.wrapperType(), dst, strict)) {
416 // Corner case, such as int->Long, which will probably fail.
417 MethodType mt = MethodType.methodType(dst, src);
418 if (strict)
419 fn = fn.asType(mt);
420 else
421 fn = MethodHandleImpl.makePairwiseConvert(fn, mt, /*strict=*/ false);
422 }
423 }
424 } else if (dst.isPrimitive()) {
425 Wrapper wdst = Wrapper.forPrimitiveType(dst);
426 if (monobox || src == wdst.wrapperType()) {
427 // Use a strongly-typed unboxer, if possible.
428 fn = ValueConversions.unboxExact(wdst, strict);
429 } else {
430 // Examples: Object->int, Number->int, Comparable->int, Byte->int
431 // must include additional conversions
432 // src must be examined at runtime, to detect Byte, Character, etc.
433 fn = (strict
434 ? ValueConversions.unboxWiden(wdst)
435 : ValueConversions.unboxCast(wdst));
436 }
437 } else {
438 // Simple reference conversion.
439 // Note: Do not check for a class hierarchy relation
440 // between src and dst. In all cases a 'null' argument
441 // will pass the cast conversion.
442 return dst;
443 }
444 assert(fn.type().parameterCount() <= 1) : "pc"+Arrays.asList(src.getSimpleName(), dst.getSimpleName(), fn);
445 return fn;
446 }
447
448 static MethodHandle makeVarargsCollector(MethodHandle target, Class<?> arrayType) {
449 MethodType type = target.type();
450 int last = type.parameterCount() - 1;
451 if (type.parameterType(last) != arrayType)
452 target = target.asType(type.changeParameterType(last, arrayType));
453 target = target.asFixedArity(); // make sure this attribute is turned off
454 return new AsVarargsCollector(target, arrayType);
455 }
456
457 static final class AsVarargsCollector extends DelegatingMethodHandle {
458 private final MethodHandle target;
459 private final Class<?> arrayType;
460 private MethodHandle asCollectorCache;
461
462 AsVarargsCollector(MethodHandle target, Class<?> arrayType) {
463 this(target.type(), target, arrayType);
464 }
465 AsVarargsCollector(MethodType type, MethodHandle target, Class<?> arrayType) {
466 super(type, target);
467 this.target = target;
468 this.arrayType = arrayType;
469 }
470
471 @Override
472 public boolean isVarargsCollector() {
473 return true;
474 }
475
476 @Override
477 protected MethodHandle getTarget() {
478 return target;
479 }
480
481 @Override
482 public MethodHandle asFixedArity() {
483 return target;
484 }
485
486 @Override
487 MethodHandle setVarargs(MemberName member) {
488 if (member.isVarargs()) return this;
489 return asFixedArity();
490 }
491
492 @Override
493 public MethodHandle withVarargs(boolean makeVarargs) {
494 if (makeVarargs) return this;
495 return asFixedArity();
496 }
497
498 @Override
499 public MethodHandle asTypeUncached(MethodType newType) {
500 MethodType type = this.type();
501 int collectArg = type.parameterCount() - 1;
502 int newArity = newType.parameterCount();
503 if (newArity == collectArg+1 &&
504 type.parameterType(collectArg).isAssignableFrom(newType.parameterType(collectArg))) {
505 // if arity and trailing parameter are compatible, do normal thing
506 return asFixedArity().asType(newType);
507 }
508 // check cache
509 MethodHandle acc = asCollectorCache;
510 if (acc != null && acc.type().parameterCount() == newArity)
511 return acc.asType(newType);
512 // build and cache a collector
513 int arrayLength = newArity - collectArg;
514 MethodHandle collector;
515 try {
516 collector = asFixedArity().asCollector(arrayType, arrayLength);
517 assert(collector.type().parameterCount() == newArity) : "newArity="+newArity+" but collector="+collector;
518 } catch (IllegalArgumentException ex) {
519 throw new WrongMethodTypeException("cannot build collector", ex);
520 }
521 asCollectorCache = collector;
522 return collector.asType(newType);
523 }
524
525 @Override
526 boolean viewAsTypeChecks(MethodType newType, boolean strict) {
527 super.viewAsTypeChecks(newType, true);
528 if (strict) return true;
529 // extra assertion for non-strict checks:
530 assert (type().lastParameterType().getComponentType()
531 .isAssignableFrom(
532 newType.lastParameterType().getComponentType()))
533 : Arrays.asList(this, newType);
534 return true;
535 }
536
537 @Override
538 public Object invokeWithArguments(Object... arguments) throws Throwable {
539 MethodType type = this.type();
540 int argc;
541 final int MAX_SAFE = 127; // 127 longs require 254 slots, which is safe to spread
542 if (arguments == null
543 || (argc = arguments.length) <= MAX_SAFE
544 || argc < type.parameterCount()) {
545 return super.invokeWithArguments(arguments);
546 }
547
548 // a jumbo invocation requires more explicit reboxing of the trailing arguments
549 int uncollected = type.parameterCount() - 1;
550 Class<?> elemType = arrayType.getComponentType();
551 int collected = argc - uncollected;
552 Object collArgs = (elemType == Object.class)
553 ? new Object[collected] : Array.newInstance(elemType, collected);
554 if (!elemType.isPrimitive()) {
555 // simple cast: just do some casting
556 try {
557 System.arraycopy(arguments, uncollected, collArgs, 0, collected);
558 } catch (ArrayStoreException ex) {
559 return super.invokeWithArguments(arguments);
560 }
561 } else {
562 // corner case of flat array requires reflection (or specialized copy loop)
563 MethodHandle arraySetter = MethodHandles.arrayElementSetter(arrayType);
564 try {
565 for (int i = 0; i < collected; i++) {
566 arraySetter.invoke(collArgs, i, arguments[uncollected + i]);
567 }
568 } catch (WrongMethodTypeException|ClassCastException ex) {
569 return super.invokeWithArguments(arguments);
570 }
571 }
572
573 // chop the jumbo list down to size and call in non-varargs mode
574 Object[] newArgs = new Object[uncollected + 1];
575 System.arraycopy(arguments, 0, newArgs, 0, uncollected);
576 newArgs[uncollected] = collArgs;
577 return asFixedArity().invokeWithArguments(newArgs);
578 }
579 }
580
581 static void checkSpreadArgument(Object av, int n) {
582 if (av == null && n == 0) {
583 return;
584 } else if (av == null) {
585 throw new NullPointerException("null array reference");
586 } else if (av instanceof Object[] array) {
587 int len = array.length;
588 if (len == n) return;
589 } else {
590 int len = java.lang.reflect.Array.getLength(av);
591 if (len == n) return;
592 }
593 // fall through to error:
594 throw newIllegalArgumentException("array is not of length "+n);
595 }
596
597 @Hidden
598 static MethodHandle selectAlternative(boolean testResult, MethodHandle target, MethodHandle fallback) {
599 if (testResult) {
600 return target;
601 } else {
602 return fallback;
603 }
604 }
605
606 // Intrinsified by C2. Counters are used during parsing to calculate branch frequencies.
607 @Hidden
608 @jdk.internal.vm.annotation.IntrinsicCandidate
609 static boolean profileBoolean(boolean result, int[] counters) {
610 // Profile is int[2] where [0] and [1] correspond to false and true occurrences respectively.
611 int idx = result ? 1 : 0;
612 try {
613 counters[idx] = Math.addExact(counters[idx], 1);
614 } catch (ArithmeticException e) {
615 // Avoid continuous overflow by halving the problematic count.
616 counters[idx] = counters[idx] / 2;
617 }
618 return result;
619 }
620
621 // Intrinsified by C2. Returns true if obj is a compile-time constant.
622 @Hidden
623 @jdk.internal.vm.annotation.IntrinsicCandidate
624 static boolean isCompileConstant(Object obj) {
625 return false;
626 }
627
628 static MethodHandle makeGuardWithTest(MethodHandle test,
629 MethodHandle target,
630 MethodHandle fallback) {
631 MethodType type = target.type();
632 assert(test.type().equals(type.changeReturnType(boolean.class)) && fallback.type().equals(type));
633 MethodType basicType = type.basicType();
634 LambdaForm form = makeGuardWithTestForm(basicType);
635 BoundMethodHandle mh;
636 try {
637 if (PROFILE_GWT) {
638 int[] counts = new int[2];
639 mh = (BoundMethodHandle)
640 BoundMethodHandle.speciesData_LLLL().factory().invokeBasic(type, form,
641 (Object) test, (Object) profile(target), (Object) profile(fallback), counts);
642 } else {
643 mh = (BoundMethodHandle)
644 BoundMethodHandle.speciesData_LLL().factory().invokeBasic(type, form,
645 (Object) test, (Object) profile(target), (Object) profile(fallback));
646 }
647 } catch (Throwable ex) {
648 throw uncaughtException(ex);
649 }
650 assert(mh.type() == type);
651 return mh;
652 }
653
654
655 static MethodHandle profile(MethodHandle target) {
656 if (DONT_INLINE_THRESHOLD >= 0) {
657 return makeBlockInliningWrapper(target);
658 } else {
659 return target;
660 }
661 }
662
663 /**
664 * Block inlining during JIT-compilation of a target method handle if it hasn't been invoked enough times.
665 * Corresponding LambdaForm has @DontInline when compiled into bytecode.
666 */
667 static MethodHandle makeBlockInliningWrapper(MethodHandle target) {
668 LambdaForm lform;
669 if (DONT_INLINE_THRESHOLD > 0) {
670 lform = Makers.PRODUCE_BLOCK_INLINING_FORM.apply(target);
671 } else {
672 lform = Makers.PRODUCE_REINVOKER_FORM.apply(target);
673 }
674 return new CountingWrapper(target, lform,
675 Makers.PRODUCE_BLOCK_INLINING_FORM, Makers.PRODUCE_REINVOKER_FORM,
676 DONT_INLINE_THRESHOLD);
677 }
678
679 private static final class Makers {
680 /** Constructs reinvoker lambda form which block inlining during JIT-compilation for a particular method handle */
681 static final Function<MethodHandle, LambdaForm> PRODUCE_BLOCK_INLINING_FORM = new Function<MethodHandle, LambdaForm>() {
682 @Override
683 public LambdaForm apply(MethodHandle target) {
684 return DelegatingMethodHandle.makeReinvokerForm(target,
685 MethodTypeForm.LF_DELEGATE_BLOCK_INLINING, CountingWrapper.class, false,
686 DelegatingMethodHandle.NF_getTarget, CountingWrapper.NF_maybeStopCounting);
687 }
688 };
689
690 /** Constructs simple reinvoker lambda form for a particular method handle */
691 static final Function<MethodHandle, LambdaForm> PRODUCE_REINVOKER_FORM = new Function<MethodHandle, LambdaForm>() {
692 @Override
693 public LambdaForm apply(MethodHandle target) {
694 return DelegatingMethodHandle.makeReinvokerForm(target,
695 MethodTypeForm.LF_DELEGATE, DelegatingMethodHandle.class, DelegatingMethodHandle.NF_getTarget);
696 }
697 };
698
699 /** Maker of type-polymorphic varargs */
700 static final ClassValue<MethodHandle[]> TYPED_COLLECTORS = new ClassValue<MethodHandle[]>() {
701 @Override
702 protected MethodHandle[] computeValue(Class<?> type) {
703 return new MethodHandle[MAX_JVM_ARITY + 1];
704 }
705 };
706 }
707
708 /**
709 * Counting method handle. It has 2 states: counting and non-counting.
710 * It is in counting state for the first n invocations and then transitions to non-counting state.
711 * Behavior in counting and non-counting states is determined by lambda forms produced by
712 * countingFormProducer & nonCountingFormProducer respectively.
713 */
714 static final class CountingWrapper extends DelegatingMethodHandle {
715 private final MethodHandle target;
716 private int count;
717 private Function<MethodHandle, LambdaForm> countingFormProducer;
718 private Function<MethodHandle, LambdaForm> nonCountingFormProducer;
719 private volatile boolean isCounting;
720
721 private CountingWrapper(MethodHandle target, LambdaForm lform,
722 Function<MethodHandle, LambdaForm> countingFromProducer,
723 Function<MethodHandle, LambdaForm> nonCountingFormProducer,
724 int count) {
725 super(target.type(), lform);
726 this.target = target;
727 this.count = count;
728 this.countingFormProducer = countingFromProducer;
729 this.nonCountingFormProducer = nonCountingFormProducer;
730 this.isCounting = (count > 0);
731 }
732
733 @Hidden
734 @Override
735 protected MethodHandle getTarget() {
736 return target;
737 }
738
739 @Override
740 public MethodHandle asTypeUncached(MethodType newType) {
741 MethodHandle newTarget = target.asType(newType);
742 MethodHandle wrapper;
743 if (isCounting) {
744 LambdaForm lform;
745 lform = countingFormProducer.apply(newTarget);
746 wrapper = new CountingWrapper(newTarget, lform, countingFormProducer, nonCountingFormProducer, DONT_INLINE_THRESHOLD);
747 } else {
748 wrapper = newTarget; // no need for a counting wrapper anymore
749 }
750 return wrapper;
751 }
752
753 boolean countDown() {
754 int c = count;
755 target.maybeCustomize(); // customize if counting happens for too long
756 if (c <= 1) {
757 // Try to limit number of updates. MethodHandle.updateForm() doesn't guarantee LF update visibility.
758 if (isCounting) {
759 isCounting = false;
760 return true;
761 } else {
762 return false;
763 }
764 } else {
765 count = c - 1;
766 return false;
767 }
768 }
769
770 @Hidden
771 static void maybeStopCounting(Object o1) {
772 final CountingWrapper wrapper = (CountingWrapper) o1;
773 if (wrapper.countDown()) {
774 // Reached invocation threshold. Replace counting behavior with a non-counting one.
775 wrapper.updateForm(new Function<>() {
776 public LambdaForm apply(LambdaForm oldForm) {
777 LambdaForm lform = wrapper.nonCountingFormProducer.apply(wrapper.target);
778 lform.compileToBytecode(); // speed up warmup by avoiding LF interpretation again after transition
779 return lform;
780 }});
781 }
782 }
783
784 static final NamedFunction NF_maybeStopCounting;
785 static {
786 Class<?> THIS_CLASS = CountingWrapper.class;
787 try {
788 NF_maybeStopCounting = new NamedFunction(THIS_CLASS.getDeclaredMethod("maybeStopCounting", Object.class));
789 } catch (ReflectiveOperationException ex) {
790 throw newInternalError(ex);
791 }
792 }
793 }
794
795 static LambdaForm makeGuardWithTestForm(MethodType basicType) {
796 LambdaForm lform = basicType.form().cachedLambdaForm(MethodTypeForm.LF_GWT);
797 if (lform != null) return lform;
798 final int THIS_MH = 0; // the BMH_LLL
799 final int ARG_BASE = 1; // start of incoming arguments
800 final int ARG_LIMIT = ARG_BASE + basicType.parameterCount();
801 int nameCursor = ARG_LIMIT;
802 final int GET_TEST = nameCursor++;
803 final int GET_TARGET = nameCursor++;
804 final int GET_FALLBACK = nameCursor++;
805 final int GET_COUNTERS = PROFILE_GWT ? nameCursor++ : -1;
806 final int CALL_TEST = nameCursor++;
807 final int PROFILE = (GET_COUNTERS != -1) ? nameCursor++ : -1;
808 final int TEST = nameCursor-1; // previous statement: either PROFILE or CALL_TEST
809 final int SELECT_ALT = nameCursor++;
810 final int CALL_TARGET = nameCursor++;
811 assert(CALL_TARGET == SELECT_ALT+1); // must be true to trigger IBG.emitSelectAlternative
812
813 Name[] names = invokeArguments(nameCursor - ARG_LIMIT, basicType);
814
815 BoundMethodHandle.SpeciesData data =
816 (GET_COUNTERS != -1) ? BoundMethodHandle.speciesData_LLLL()
817 : BoundMethodHandle.speciesData_LLL();
818 names[THIS_MH] = names[THIS_MH].withConstraint(data);
819 names[GET_TEST] = new Name(data.getterFunction(0), names[THIS_MH]);
820 names[GET_TARGET] = new Name(data.getterFunction(1), names[THIS_MH]);
821 names[GET_FALLBACK] = new Name(data.getterFunction(2), names[THIS_MH]);
822 if (GET_COUNTERS != -1) {
823 names[GET_COUNTERS] = new Name(data.getterFunction(3), names[THIS_MH]);
824 }
825 Object[] invokeArgs = Arrays.copyOfRange(names, 0, ARG_LIMIT, Object[].class);
826
827 // call test
828 MethodType testType = basicType.changeReturnType(boolean.class).basicType();
829 invokeArgs[0] = names[GET_TEST];
830 names[CALL_TEST] = new Name(testType, invokeArgs);
831
832 // profile branch
833 if (PROFILE != -1) {
834 names[PROFILE] = new Name(getFunction(NF_profileBoolean), names[CALL_TEST], names[GET_COUNTERS]);
835 }
836 // call selectAlternative
837 names[SELECT_ALT] = new Name(new NamedFunction(
838 makeIntrinsic(getConstantHandle(MH_selectAlternative), Intrinsic.SELECT_ALTERNATIVE)),
839 names[TEST], names[GET_TARGET], names[GET_FALLBACK]);
840
841 // call target or fallback
842 invokeArgs[0] = names[SELECT_ALT];
843 names[CALL_TARGET] = new Name(basicType, invokeArgs);
844
845 lform = LambdaForm.create(basicType.parameterCount() + 1, names, /*forceInline=*/true, Kind.GUARD);
846
847 return basicType.form().setCachedLambdaForm(MethodTypeForm.LF_GWT, lform);
848 }
849
850 /**
851 * The LambdaForm shape for catchException combinator is the following:
852 * <blockquote><pre>{@code
853 * guardWithCatch=Lambda(a0:L,a1:L,a2:L)=>{
854 * t3:L=BoundMethodHandle$Species_LLLLL.argL0(a0:L);
855 * t4:L=BoundMethodHandle$Species_LLLLL.argL1(a0:L);
856 * t5:L=BoundMethodHandle$Species_LLLLL.argL2(a0:L);
857 * t6:L=BoundMethodHandle$Species_LLLLL.argL3(a0:L);
858 * t7:L=BoundMethodHandle$Species_LLLLL.argL4(a0:L);
859 * t8:L=MethodHandle.invokeBasic(t6:L,a1:L,a2:L);
860 * t9:L=MethodHandleImpl.guardWithCatch(t3:L,t4:L,t5:L,t8:L);
861 * t10:I=MethodHandle.invokeBasic(t7:L,t9:L);t10:I}
862 * }</pre></blockquote>
863 *
864 * argL0 and argL2 are target and catcher method handles. argL1 is exception class.
865 * argL3 and argL4 are auxiliary method handles: argL3 boxes arguments and wraps them into Object[]
866 * (ValueConversions.array()) and argL4 unboxes result if necessary (ValueConversions.unbox()).
867 *
868 * Having t8 and t10 passed outside and not hardcoded into a lambda form allows to share lambda forms
869 * among catchException combinators with the same basic type.
870 */
871 private static LambdaForm makeGuardWithCatchForm(MethodType basicType) {
872 LambdaForm lform = basicType.form().cachedLambdaForm(MethodTypeForm.LF_GWC);
873 if (lform != null) {
874 return lform;
875 }
876 final int THIS_MH = 0; // the BMH_LLLLL
877 final int ARG_BASE = 1; // start of incoming arguments
878 final int ARG_LIMIT = ARG_BASE + basicType.parameterCount();
879
880 int nameCursor = ARG_LIMIT;
881 final int GET_TARGET = nameCursor++;
882 final int GET_CLASS = nameCursor++;
883 final int GET_CATCHER = nameCursor++;
884 final int GET_COLLECT_ARGS = nameCursor++;
885 final int GET_UNBOX_RESULT = nameCursor++;
886 final int BOXED_ARGS = nameCursor++;
887 final int TRY_CATCH = nameCursor++;
888 final int UNBOX_RESULT = nameCursor++;
889
890 Name[] names = invokeArguments(nameCursor - ARG_LIMIT, basicType);
891
892 BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_LLLLL();
893 names[THIS_MH] = names[THIS_MH].withConstraint(data);
894 names[GET_TARGET] = new Name(data.getterFunction(0), names[THIS_MH]);
895 names[GET_CLASS] = new Name(data.getterFunction(1), names[THIS_MH]);
896 names[GET_CATCHER] = new Name(data.getterFunction(2), names[THIS_MH]);
897 names[GET_COLLECT_ARGS] = new Name(data.getterFunction(3), names[THIS_MH]);
898 names[GET_UNBOX_RESULT] = new Name(data.getterFunction(4), names[THIS_MH]);
899
900 // FIXME: rework argument boxing/result unboxing logic for LF interpretation
901
902 // t_{i}:L=MethodHandle.invokeBasic(collectArgs:L,a1:L,...);
903 MethodType collectArgsType = basicType.changeReturnType(Object.class);
904 MethodHandle invokeBasic = MethodHandles.basicInvoker(collectArgsType);
905 Object[] args = new Object[invokeBasic.type().parameterCount()];
906 args[0] = names[GET_COLLECT_ARGS];
907 System.arraycopy(names, ARG_BASE, args, 1, ARG_LIMIT-ARG_BASE);
908 names[BOXED_ARGS] = new Name(new NamedFunction(makeIntrinsic(invokeBasic, Intrinsic.GUARD_WITH_CATCH)), args);
909
910 // t_{i+1}:L=MethodHandleImpl.guardWithCatch(target:L,exType:L,catcher:L,t_{i}:L);
911 Object[] gwcArgs = new Object[] {names[GET_TARGET], names[GET_CLASS], names[GET_CATCHER], names[BOXED_ARGS]};
912 names[TRY_CATCH] = new Name(getFunction(NF_guardWithCatch), gwcArgs);
913
914 // t_{i+2}:I=MethodHandle.invokeBasic(unbox:L,t_{i+1}:L);
915 MethodHandle invokeBasicUnbox = MethodHandles.basicInvoker(MethodType.methodType(basicType.rtype(), Object.class));
916 Object[] unboxArgs = new Object[] {names[GET_UNBOX_RESULT], names[TRY_CATCH]};
917 names[UNBOX_RESULT] = new Name(invokeBasicUnbox, unboxArgs);
918
919 lform = LambdaForm.create(basicType.parameterCount() + 1, names, Kind.GUARD_WITH_CATCH);
920
921 return basicType.form().setCachedLambdaForm(MethodTypeForm.LF_GWC, lform);
922 }
923
924 static MethodHandle makeGuardWithCatch(MethodHandle target,
925 Class<? extends Throwable> exType,
926 MethodHandle catcher) {
927 MethodType type = target.type();
928 LambdaForm form = makeGuardWithCatchForm(type.basicType());
929
930 // Prepare auxiliary method handles used during LambdaForm interpretation.
931 // Box arguments and wrap them into Object[]: ValueConversions.array().
932 MethodType varargsType = type.changeReturnType(Object[].class);
933 MethodHandle collectArgs = varargsArray(type.parameterCount()).asType(varargsType);
934 MethodHandle unboxResult = unboxResultHandle(type.returnType());
935
936 BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_LLLLL();
937 BoundMethodHandle mh;
938 try {
939 mh = (BoundMethodHandle) data.factory().invokeBasic(type, form, (Object) target, (Object) exType,
940 (Object) catcher, (Object) collectArgs, (Object) unboxResult);
941 } catch (Throwable ex) {
942 throw uncaughtException(ex);
943 }
944 assert(mh.type() == type);
945 return mh;
946 }
947
948 /**
949 * Intrinsified during LambdaForm compilation
950 * (see {@link InvokerBytecodeGenerator#emitGuardWithCatch emitGuardWithCatch}).
951 */
952 @Hidden
953 static Object guardWithCatch(MethodHandle target, Class<? extends Throwable> exType, MethodHandle catcher,
954 Object... av) throws Throwable {
955 // Use asFixedArity() to avoid unnecessary boxing of last argument for VarargsCollector case.
956 try {
957 return target.asFixedArity().invokeWithArguments(av);
958 } catch (Throwable t) {
959 if (!exType.isInstance(t)) throw t;
960 return catcher.asFixedArity().invokeWithArguments(prepend(av, t));
961 }
962 }
963
964 /** Prepend elements to an array. */
965 @Hidden
966 private static Object[] prepend(Object[] array, Object... elems) {
967 int nArray = array.length;
968 int nElems = elems.length;
969 Object[] newArray = new Object[nArray + nElems];
970 System.arraycopy(elems, 0, newArray, 0, nElems);
971 System.arraycopy(array, 0, newArray, nElems, nArray);
972 return newArray;
973 }
974
975 static MethodHandle throwException(MethodType type) {
976 assert(Throwable.class.isAssignableFrom(type.parameterType(0)));
977 int arity = type.parameterCount();
978 if (arity > 1) {
979 MethodHandle mh = throwException(type.dropParameterTypes(1, arity));
980 mh = MethodHandles.dropArgumentsTrusted(mh, 1, Arrays.copyOfRange(type.ptypes(), 1, arity));
981 return mh;
982 }
983 return makePairwiseConvert(getFunction(NF_throwException).resolvedHandle(), type, false, true);
984 }
985
986 static <T extends Throwable> Empty throwException(T t) throws T { throw t; }
987
988 static MethodHandle[] FAKE_METHOD_HANDLE_INVOKE = new MethodHandle[2];
989 static MethodHandle fakeMethodHandleInvoke(MemberName method) {
990 assert(method.isMethodHandleInvoke());
991 int idx = switch (method.getName()) {
992 case "invoke" -> 0;
993 case "invokeExact" -> 1;
994 default -> throw new InternalError(method.getName());
995 };
996 MethodHandle mh = FAKE_METHOD_HANDLE_INVOKE[idx];
997 if (mh != null) return mh;
998 MethodType type = MethodType.methodType(Object.class, UnsupportedOperationException.class,
999 MethodHandle.class, Object[].class);
1000 mh = throwException(type);
1001 mh = mh.bindTo(new UnsupportedOperationException("cannot reflectively invoke MethodHandle"));
1002 if (!method.getInvocationType().equals(mh.type()))
1003 throw new InternalError(method.toString());
1004 mh = mh.withInternalMemberName(method, false);
1005 mh = mh.withVarargs(true);
1006 assert(method.isVarargs());
1007 FAKE_METHOD_HANDLE_INVOKE[idx] = mh;
1008 return mh;
1009 }
1010 static MethodHandle fakeVarHandleInvoke(MemberName method) {
1011 // TODO caching, is it necessary?
1012 MethodType type = MethodType.methodType(method.getMethodType().returnType(),
1013 UnsupportedOperationException.class,
1014 VarHandle.class, Object[].class);
1015 MethodHandle mh = throwException(type);
1016 mh = mh.bindTo(new UnsupportedOperationException("cannot reflectively invoke VarHandle"));
1017 if (!method.getInvocationType().equals(mh.type()))
1018 throw new InternalError(method.toString());
1019 mh = mh.withInternalMemberName(method, false);
1020 mh = mh.asVarargsCollector(Object[].class);
1021 assert(method.isVarargs());
1022 return mh;
1023 }
1024
1025 /**
1026 * Create an alias for the method handle which, when called,
1027 * appears to be called from the same class loader and protection domain
1028 * as hostClass.
1029 * This is an expensive no-op unless the method which is called
1030 * is sensitive to its caller. A small number of system methods
1031 * are in this category, including Class.forName and Method.invoke.
1032 */
1033 static MethodHandle bindCaller(MethodHandle mh, Class<?> hostClass) {
1034 return BindCaller.bindCaller(mh, hostClass);
1035 }
1036
1037 // Put the whole mess into its own nested class.
1038 // That way we can lazily load the code and set up the constants.
1039 private static class BindCaller {
1040
1041 private static final ClassDesc CD_Object_array = ReferenceClassDescImpl.ofValidated("[Ljava/lang/Object;");
1042 private static final MethodType INVOKER_MT = MethodType.methodType(Object.class, MethodHandle.class, Object[].class);
1043 private static final MethodType REFLECT_INVOKER_MT = MethodType.methodType(Object.class, MethodHandle.class, Object.class, Object[].class);
1044
1045 static MethodHandle bindCaller(MethodHandle mh, Class<?> hostClass) {
1046 // Code in the boot layer should now be careful while creating method handles or
1047 // functional interface instances created from method references to @CallerSensitive methods,
1048 // it needs to be ensured the handles or interface instances are kept safe and are not passed
1049 // from the boot layer to untrusted code.
1050 if (hostClass == null
1051 || (hostClass.isArray() ||
1052 hostClass.isPrimitive() ||
1053 hostClass.getName().startsWith("java.lang.invoke."))) {
1054 throw new InternalError(); // does not happen, and should not anyway
1055 }
1056
1057 MemberName member = mh.internalMemberName();
1058 if (member != null) {
1059 // Look up the CSM adapter method with the same method name
1060 // but with an additional caller class parameter. If present,
1061 // bind the adapter's method handle with the lookup class as
1062 // the caller class argument
1063 MemberName csmAdapter = IMPL_LOOKUP.resolveOrNull(member.getReferenceKind(),
1064 new MemberName(member.getDeclaringClass(),
1065 member.getName(),
1066 member.getMethodType().appendParameterTypes(Class.class),
1067 member.getReferenceKind()));
1068 if (csmAdapter != null) {
1069 assert !csmAdapter.isCallerSensitive();
1070 MethodHandle dmh = DirectMethodHandle.make(csmAdapter);
1071 dmh = MethodHandles.insertArguments(dmh, dmh.type().parameterCount() - 1, hostClass);
1072 dmh = new WrappedMember(dmh, mh.type(), member, mh.isInvokeSpecial(), hostClass);
1073 return dmh;
1074 }
1075 }
1076
1077 // If no adapter method for CSM with an additional Class parameter
1078 // is present, then inject an invoker class that is the caller
1079 // invoking the method handle of the CSM
1080 try {
1081 return bindCallerWithInjectedInvoker(mh, hostClass);
1082 } catch (ReflectiveOperationException ex) {
1083 throw uncaughtException(ex);
1084 }
1085 }
1086
1087 private static MethodHandle bindCallerWithInjectedInvoker(MethodHandle mh, Class<?> hostClass)
1088 throws ReflectiveOperationException
1089 {
1090 // For simplicity, convert mh to a varargs-like method.
1091 MethodHandle vamh = prepareForInvoker(mh);
1092 // Cache the result of makeInjectedInvoker once per argument class.
1093 MethodHandle bccInvoker = CV_makeInjectedInvoker.get(hostClass).invoker();
1094 return restoreToType(bccInvoker.bindTo(vamh), mh, hostClass);
1095 }
1096
1097 private static Class<?> makeInjectedInvoker(Class<?> targetClass) {
1098 /*
1099 * The invoker class defined to the same class loader as the lookup class
1100 * but in an unnamed package so that the class bytes can be cached and
1101 * reused for any @CSM.
1102 *
1103 * @CSM must be public and exported if called by any module.
1104 */
1105 String name = targetClass.getName() + "$$InjectedInvoker";
1106 if (targetClass.isHidden()) {
1107 // use the original class name
1108 name = name.replace('/', '_');
1109 }
1110 name = name.replace('.', '/');
1111 Class<?> invokerClass = new Lookup(targetClass)
1112 .makeHiddenClassDefiner(name, INJECTED_INVOKER_TEMPLATE, dumper(), NESTMATE_CLASS)
1113 .defineClass(true, targetClass);
1114 assert checkInjectedInvoker(targetClass, invokerClass);
1115 return invokerClass;
1116 }
1117
1118 private static ClassValue<InjectedInvokerHolder> CV_makeInjectedInvoker = new ClassValue<>() {
1119 @Override
1120 protected InjectedInvokerHolder computeValue(Class<?> hostClass) {
1121 return new InjectedInvokerHolder(makeInjectedInvoker(hostClass));
1122 }
1123 };
1124
1125 /*
1126 * Returns a method handle of an invoker class injected for reflection
1127 * implementation use with the following signature:
1128 * reflect_invoke_V(MethodHandle mh, Object target, Object[] args)
1129 *
1130 * Method::invoke on a caller-sensitive method will call
1131 * MethodAccessorImpl::invoke(Object, Object[]) through reflect_invoke_V
1132 * target.csm(args)
1133 * NativeMethodAccessorImpl::invoke(target, args)
1134 * MethodAccessImpl::invoke(target, args)
1135 * InjectedInvoker::reflect_invoke_V(vamh, target, args);
1136 * method::invoke(target, args)
1137 * p.Foo::m
1138 *
1139 * An injected invoker class is a hidden class which has the same
1140 * defining class loader, runtime package, and protection domain
1141 * as the given caller class.
1142 */
1143 static MethodHandle reflectiveInvoker(Class<?> caller) {
1144 return BindCaller.CV_makeInjectedInvoker.get(caller).reflectInvoker();
1145 }
1146
1147 private static final class InjectedInvokerHolder {
1148 private final Class<?> invokerClass;
1149 // lazily resolved and cached DMH(s) of invoke_V methods
1150 private MethodHandle invoker;
1151 private MethodHandle reflectInvoker;
1152
1153 private InjectedInvokerHolder(Class<?> invokerClass) {
1154 this.invokerClass = invokerClass;
1155 }
1156
1157 private MethodHandle invoker() {
1158 var mh = invoker;
1159 if (mh == null) {
1160 try {
1161 invoker = mh = IMPL_LOOKUP.findStatic(invokerClass, "invoke_V", INVOKER_MT);
1162 } catch (Error | RuntimeException ex) {
1163 throw ex;
1164 } catch (Throwable ex) {
1165 throw new InternalError(ex);
1166 }
1167 }
1168 return mh;
1169 }
1170
1171 private MethodHandle reflectInvoker() {
1172 var mh = reflectInvoker;
1173 if (mh == null) {
1174 try {
1175 reflectInvoker = mh = IMPL_LOOKUP.findStatic(invokerClass, "reflect_invoke_V", REFLECT_INVOKER_MT);
1176 } catch (Error | RuntimeException ex) {
1177 throw ex;
1178 } catch (Throwable ex) {
1179 throw new InternalError(ex);
1180 }
1181 }
1182 return mh;
1183 }
1184 }
1185
1186 // Adapt mh so that it can be called directly from an injected invoker:
1187 private static MethodHandle prepareForInvoker(MethodHandle mh) {
1188 mh = mh.asFixedArity();
1189 MethodType mt = mh.type();
1190 int arity = mt.parameterCount();
1191 MethodHandle vamh = mh.asType(mt.generic());
1192 vamh.internalForm().compileToBytecode(); // eliminate LFI stack frames
1193 vamh = vamh.asSpreader(Object[].class, arity);
1194 vamh.internalForm().compileToBytecode(); // eliminate LFI stack frames
1195 return vamh;
1196 }
1197
1198 // Undo the adapter effect of prepareForInvoker:
1199 private static MethodHandle restoreToType(MethodHandle vamh,
1200 MethodHandle original,
1201 Class<?> hostClass) {
1202 MethodType type = original.type();
1203 MethodHandle mh = vamh.asCollector(Object[].class, type.parameterCount());
1204 MemberName member = original.internalMemberName();
1205 mh = mh.asType(type);
1206 mh = new WrappedMember(mh, type, member, original.isInvokeSpecial(), hostClass);
1207 return mh;
1208 }
1209
1210 private static boolean checkInjectedInvoker(Class<?> hostClass, Class<?> invokerClass) {
1211 assert (hostClass.getClassLoader() == invokerClass.getClassLoader()) : hostClass.getName()+" (CL)";
1212 try {
1213 assert (hostClass.getProtectionDomain() == invokerClass.getProtectionDomain()) : hostClass.getName()+" (PD)";
1214 } catch (SecurityException ex) {
1215 // Self-check was blocked by security manager. This is OK.
1216 }
1217 try {
1218 // Test the invoker to ensure that it really injects into the right place.
1219 MethodHandle invoker = IMPL_LOOKUP.findStatic(invokerClass, "invoke_V", INVOKER_MT);
1220 MethodHandle vamh = prepareForInvoker(MH_checkCallerClass);
1221 return (boolean)invoker.invoke(vamh, new Object[]{ invokerClass });
1222 } catch (Error|RuntimeException ex) {
1223 throw ex;
1224 } catch (Throwable ex) {
1225 throw new InternalError(ex);
1226 }
1227 }
1228
1229 private static final MethodHandle MH_checkCallerClass;
1230 static {
1231 final Class<?> THIS_CLASS = BindCaller.class;
1232 assert(checkCallerClass(THIS_CLASS));
1233 try {
1234 MH_checkCallerClass = IMPL_LOOKUP
1235 .findStatic(THIS_CLASS, "checkCallerClass",
1236 MethodType.methodType(boolean.class, Class.class));
1237 assert((boolean) MH_checkCallerClass.invokeExact(THIS_CLASS));
1238 } catch (Throwable ex) {
1239 throw new InternalError(ex);
1240 }
1241 }
1242
1243 @CallerSensitive
1244 @ForceInline // to ensure Reflection.getCallerClass optimization
1245 private static boolean checkCallerClass(Class<?> expected) {
1246 // This method is called via MH_checkCallerClass and so it's correct to ask for the immediate caller here.
1247 Class<?> actual = Reflection.getCallerClass();
1248 if (actual != expected)
1249 throw new InternalError("found " + actual.getName() + ", expected " + expected.getName());
1250 return true;
1251 }
1252
1253 private static final byte[] INJECTED_INVOKER_TEMPLATE = generateInvokerTemplate();
1254
1255 /** Produces byte code for a class that is used as an injected invoker. */
1256 private static byte[] generateInvokerTemplate() {
1257 // private static class InjectedInvoker {
1258 // /* this is used to wrap DMH(s) of caller-sensitive methods */
1259 // @Hidden
1260 // static Object invoke_V(MethodHandle vamh, Object[] args) throws Throwable {
1261 // return vamh.invokeExact(args);
1262 // }
1263 // /* this is used in caller-sensitive reflective method accessor */
1264 // @Hidden
1265 // static Object reflect_invoke_V(MethodHandle vamh, Object target, Object[] args) throws Throwable {
1266 // return vamh.invokeExact(target, args);
1267 // }
1268 // }
1269 // }
1270 return ClassFile.of().build(ReferenceClassDescImpl.ofValidated("LInjectedInvoker;"), clb -> clb
1271 .withFlags(ACC_PRIVATE | ACC_SUPER)
1272 .withMethodBody(
1273 "invoke_V",
1274 MethodTypeDescImpl.ofValidated(CD_Object, CD_MethodHandle, CD_Object_array),
1275 ACC_STATIC,
1276 cob -> cob.aload(0)
1277 .aload(1)
1278 .invokevirtual(CD_MethodHandle, "invokeExact", MethodTypeDescImpl.ofValidated(CD_Object, CD_Object_array))
1279 .areturn())
1280 .withMethodBody(
1281 "reflect_invoke_V",
1282 MethodTypeDescImpl.ofValidated(CD_Object, CD_MethodHandle, CD_Object, CD_Object_array),
1283 ACC_STATIC,
1284 cob -> cob.aload(0)
1285 .aload(1)
1286 .aload(2)
1287 .invokevirtual(CD_MethodHandle, "invokeExact", MethodTypeDescImpl.ofValidated(CD_Object, CD_Object, CD_Object_array))
1288 .areturn()));
1289 }
1290 }
1291
1292 /** This subclass allows a wrapped method handle to be re-associated with an arbitrary member name. */
1293 static final class WrappedMember extends DelegatingMethodHandle {
1294 private final MethodHandle target;
1295 private final MemberName member;
1296 private final Class<?> callerClass;
1297 private final boolean isInvokeSpecial;
1298
1299 private WrappedMember(MethodHandle target, MethodType type,
1300 MemberName member, boolean isInvokeSpecial,
1301 Class<?> callerClass) {
1302 super(type, target);
1303 this.target = target;
1304 this.member = member;
1305 this.callerClass = callerClass;
1306 this.isInvokeSpecial = isInvokeSpecial;
1307 }
1308
1309 @Override
1310 MemberName internalMemberName() {
1311 return member;
1312 }
1313 @Override
1314 Class<?> internalCallerClass() {
1315 return callerClass;
1316 }
1317 @Override
1318 boolean isInvokeSpecial() {
1319 return isInvokeSpecial;
1320 }
1321 @Override
1322 protected MethodHandle getTarget() {
1323 return target;
1324 }
1325 @Override
1326 public MethodHandle asTypeUncached(MethodType newType) {
1327 // This MH is an alias for target, except for the MemberName
1328 // Drop the MemberName if there is any conversion.
1329 return target.asType(newType);
1330 }
1331 }
1332
1333 static MethodHandle makeWrappedMember(MethodHandle target, MemberName member, boolean isInvokeSpecial) {
1334 if (member.equals(target.internalMemberName()) && isInvokeSpecial == target.isInvokeSpecial())
1335 return target;
1336 return new WrappedMember(target, target.type(), member, isInvokeSpecial, null);
1337 }
1338
1339 /** Intrinsic IDs */
1340 /*non-public*/
1341 enum Intrinsic {
1342 SELECT_ALTERNATIVE,
1343 GUARD_WITH_CATCH,
1344 TRY_FINALLY,
1345 TABLE_SWITCH,
1346 LOOP,
1347 ARRAY_LOAD,
1348 ARRAY_STORE,
1349 ARRAY_LENGTH,
1350 IDENTITY,
1351 ZERO,
1352 NONE // no intrinsic associated
1353 }
1354
1355 /** Mark arbitrary method handle as intrinsic.
1356 * InvokerBytecodeGenerator uses this info to produce more efficient bytecode shape. */
1357 static final class IntrinsicMethodHandle extends DelegatingMethodHandle {
1358 private final MethodHandle target;
1359 private final Intrinsic intrinsicName;
1360 private final Object intrinsicData;
1361
1362 IntrinsicMethodHandle(MethodHandle target, Intrinsic intrinsicName) {
1363 this(target, intrinsicName, null);
1364 }
1365
1366 IntrinsicMethodHandle(MethodHandle target, Intrinsic intrinsicName, Object intrinsicData) {
1367 super(target.type(), target);
1368 this.target = target;
1369 this.intrinsicName = intrinsicName;
1370 this.intrinsicData = intrinsicData;
1371 }
1372
1373 @Override
1374 protected MethodHandle getTarget() {
1375 return target;
1376 }
1377
1378 @Override
1379 Intrinsic intrinsicName() {
1380 return intrinsicName;
1381 }
1382
1383 @Override
1384 Object intrinsicData() {
1385 return intrinsicData;
1386 }
1387
1388 @Override
1389 public MethodHandle asTypeUncached(MethodType newType) {
1390 // This MH is an alias for target, except for the intrinsic name
1391 // Drop the name if there is any conversion.
1392 return target.asType(newType);
1393 }
1394
1395 @Override
1396 String internalProperties() {
1397 return super.internalProperties() +
1398 "\n& Intrinsic="+intrinsicName;
1399 }
1400
1401 @Override
1402 public MethodHandle asCollector(Class<?> arrayType, int arrayLength) {
1403 if (intrinsicName == Intrinsic.IDENTITY) {
1404 MethodType resultType = type().asCollectorType(arrayType, type().parameterCount() - 1, arrayLength);
1405 MethodHandle newArray = MethodHandleImpl.varargsArray(arrayType, arrayLength);
1406 return newArray.asType(resultType);
1407 }
1408 return super.asCollector(arrayType, arrayLength);
1409 }
1410 }
1411
1412 static MethodHandle makeIntrinsic(MethodHandle target, Intrinsic intrinsicName) {
1413 return makeIntrinsic(target, intrinsicName, null);
1414 }
1415
1416 static MethodHandle makeIntrinsic(MethodHandle target, Intrinsic intrinsicName, Object intrinsicData) {
1417 if (intrinsicName == target.intrinsicName())
1418 return target;
1419 return new IntrinsicMethodHandle(target, intrinsicName, intrinsicData);
1420 }
1421
1422 static MethodHandle makeIntrinsic(MethodType type, LambdaForm form, Intrinsic intrinsicName) {
1423 return new IntrinsicMethodHandle(SimpleMethodHandle.make(type, form), intrinsicName);
1424 }
1425
1426 private static final @Stable MethodHandle[] ARRAYS = new MethodHandle[MAX_ARITY + 1];
1427
1428 /** Return a method handle that takes the indicated number of Object
1429 * arguments and returns an Object array of them, as if for varargs.
1430 */
1431 static MethodHandle varargsArray(int nargs) {
1432 MethodHandle mh = ARRAYS[nargs];
1433 if (mh != null) {
1434 return mh;
1435 }
1436 mh = makeCollector(Object[].class, nargs);
1437 assert(assertCorrectArity(mh, nargs));
1438 return ARRAYS[nargs] = mh;
1439 }
1440
1441 /** Return a method handle that takes the indicated number of
1442 * typed arguments and returns an array of them.
1443 * The type argument is the array type.
1444 */
1445 static MethodHandle varargsArray(Class<?> arrayType, int nargs) {
1446 Class<?> elemType = arrayType.getComponentType();
1447 if (elemType == null) throw new IllegalArgumentException("not an array: "+arrayType);
1448 if (nargs >= MAX_JVM_ARITY/2 - 1) {
1449 int slots = nargs;
1450 final int MAX_ARRAY_SLOTS = MAX_JVM_ARITY - 1; // 1 for receiver MH
1451 if (slots <= MAX_ARRAY_SLOTS && elemType.isPrimitive())
1452 slots *= Wrapper.forPrimitiveType(elemType).stackSlots();
1453 if (slots > MAX_ARRAY_SLOTS)
1454 throw new IllegalArgumentException("too many arguments: "+arrayType.getSimpleName()+", length "+nargs);
1455 }
1456 if (elemType == Object.class)
1457 return varargsArray(nargs);
1458 // other cases: primitive arrays, subtypes of Object[]
1459 MethodHandle cache[] = Makers.TYPED_COLLECTORS.get(elemType);
1460 MethodHandle mh = nargs < cache.length ? cache[nargs] : null;
1461 if (mh != null) return mh;
1462 mh = makeCollector(arrayType, nargs);
1463 assert(assertCorrectArity(mh, nargs));
1464 if (nargs < cache.length)
1465 cache[nargs] = mh;
1466 return mh;
1467 }
1468
1469 private static boolean assertCorrectArity(MethodHandle mh, int arity) {
1470 assert(mh.type().parameterCount() == arity) : "arity != "+arity+": "+mh;
1471 return true;
1472 }
1473
1474 static final int MAX_JVM_ARITY = 255; // limit imposed by the JVM
1475
1476 /*non-public*/
1477 static void assertSame(Object mh1, Object mh2) {
1478 if (mh1 != mh2) {
1479 String msg = String.format("mh1 != mh2: mh1 = %s (form: %s); mh2 = %s (form: %s)",
1480 mh1, ((MethodHandle)mh1).form,
1481 mh2, ((MethodHandle)mh2).form);
1482 throw newInternalError(msg);
1483 }
1484 }
1485
1486 // Local constant functions:
1487
1488 /* non-public */
1489 static final byte NF_checkSpreadArgument = 0,
1490 NF_guardWithCatch = 1,
1491 NF_throwException = 2,
1492 NF_tryFinally = 3,
1493 NF_loop = 4,
1494 NF_profileBoolean = 5,
1495 NF_tableSwitch = 6,
1496 NF_LIMIT = 7;
1497
1498 private static final @Stable NamedFunction[] NFS = new NamedFunction[NF_LIMIT];
1499
1500 static NamedFunction getFunction(byte func) {
1501 NamedFunction nf = NFS[func];
1502 if (nf != null) {
1503 return nf;
1504 }
1505 return NFS[func] = createFunction(func);
1506 }
1507
1508 private static NamedFunction createFunction(byte func) {
1509 try {
1510 return switch (func) {
1511 case NF_checkSpreadArgument -> new NamedFunction(MethodHandleImpl.class
1512 .getDeclaredMethod("checkSpreadArgument", Object.class, int.class));
1513 case NF_guardWithCatch -> new NamedFunction(MethodHandleImpl.class
1514 .getDeclaredMethod("guardWithCatch", MethodHandle.class, Class.class,
1515 MethodHandle.class, Object[].class));
1516 case NF_tryFinally -> new NamedFunction(MethodHandleImpl.class
1517 .getDeclaredMethod("tryFinally", MethodHandle.class, MethodHandle.class, Object[].class));
1518 case NF_loop -> new NamedFunction(MethodHandleImpl.class
1519 .getDeclaredMethod("loop", BasicType[].class, LoopClauses.class, Object[].class));
1520 case NF_throwException -> new NamedFunction(MethodHandleImpl.class
1521 .getDeclaredMethod("throwException", Throwable.class));
1522 case NF_profileBoolean -> new NamedFunction(MethodHandleImpl.class
1523 .getDeclaredMethod("profileBoolean", boolean.class, int[].class));
1524 case NF_tableSwitch -> new NamedFunction(MethodHandleImpl.class
1525 .getDeclaredMethod("tableSwitch", int.class, MethodHandle.class, CasesHolder.class, Object[].class));
1526 default -> throw new InternalError("Undefined function: " + func);
1527 };
1528 } catch (ReflectiveOperationException ex) {
1529 throw newInternalError(ex);
1530 }
1531 }
1532
1533 static {
1534 SharedSecrets.setJavaLangInvokeAccess(new JavaLangInvokeAccess() {
1535 @Override
1536 public Class<?> getDeclaringClass(Object rmname) {
1537 ResolvedMethodName method = (ResolvedMethodName)rmname;
1538 return method.declaringClass();
1539 }
1540
1541 @Override
1542 public MethodType getMethodType(String descriptor, ClassLoader loader) {
1543 return MethodType.fromDescriptor(descriptor, loader);
1544 }
1545
1546 public boolean isCallerSensitive(int flags) {
1547 return (flags & MN_CALLER_SENSITIVE) == MN_CALLER_SENSITIVE;
1548 }
1549
1550 public boolean isHiddenMember(int flags) {
1551 return (flags & MN_HIDDEN_MEMBER) == MN_HIDDEN_MEMBER;
1552 }
1553
1554 public boolean isNullRestrictedField(MethodHandle mh) {
1555 var memberName = mh.internalMemberName();
1556 assert memberName.isField();
1557 return memberName.isNullRestricted();
1558 }
1559
1560 @Override
1561 public Map<String, byte[]> generateHolderClasses(Stream<String> traces) {
1562 return GenerateJLIClassesHelper.generateHolderClasses(traces);
1563 }
1564
1565 @Override
1566 public VarHandle memorySegmentViewHandle(Class<?> carrier, long alignmentMask, ByteOrder order) {
1567 return VarHandles.memorySegmentViewHandle(carrier, alignmentMask, order);
1568 }
1569
1570 @Override
1571 public MethodHandle nativeMethodHandle(NativeEntryPoint nep) {
1572 return NativeMethodHandle.make(nep);
1573 }
1574
1575 @Override
1576 public VarHandle filterValue(VarHandle target, MethodHandle filterToTarget, MethodHandle filterFromTarget) {
1577 return VarHandles.filterValue(target, filterToTarget, filterFromTarget);
1578 }
1579
1580 @Override
1581 public VarHandle filterCoordinates(VarHandle target, int pos, MethodHandle... filters) {
1582 return VarHandles.filterCoordinates(target, pos, filters);
1583 }
1584
1585 @Override
1586 public VarHandle dropCoordinates(VarHandle target, int pos, Class<?>... valueTypes) {
1587 return VarHandles.dropCoordinates(target, pos, valueTypes);
1588 }
1589
1590 @Override
1591 public VarHandle permuteCoordinates(VarHandle target, List<Class<?>> newCoordinates, int... reorder) {
1592 return VarHandles.permuteCoordinates(target, newCoordinates, reorder);
1593 }
1594
1595 @Override
1596 public VarHandle collectCoordinates(VarHandle target, int pos, MethodHandle filter) {
1597 return VarHandles.collectCoordinates(target, pos, filter);
1598 }
1599
1600 @Override
1601 public VarHandle insertCoordinates(VarHandle target, int pos, Object... values) {
1602 return VarHandles.insertCoordinates(target, pos, values);
1603 }
1604
1605
1606 @Override
1607 public MethodHandle unreflectConstructor(Constructor<?> ctor) throws IllegalAccessException {
1608 return IMPL_LOOKUP.unreflectConstructor(ctor);
1609 }
1610
1611 @Override
1612 public MethodHandle unreflectField(Field field, boolean isSetter) throws IllegalAccessException {
1613 return isSetter ? IMPL_LOOKUP.unreflectSetter(field) : IMPL_LOOKUP.unreflectGetter(field);
1614 }
1615
1616 @Override
1617 public MethodHandle findVirtual(Class<?> defc, String name, MethodType type) throws IllegalAccessException {
1618 try {
1619 return IMPL_LOOKUP.findVirtual(defc, name, type);
1620 } catch (NoSuchMethodException e) {
1621 return null;
1622 }
1623 }
1624
1625 @Override
1626 public MethodHandle findStatic(Class<?> defc, String name, MethodType type) throws IllegalAccessException {
1627 try {
1628 return IMPL_LOOKUP.findStatic(defc, name, type);
1629 } catch (NoSuchMethodException e) {
1630 return null;
1631 }
1632 }
1633
1634 @Override
1635 public MethodHandle reflectiveInvoker(Class<?> caller) {
1636 Objects.requireNonNull(caller);
1637 return BindCaller.reflectiveInvoker(caller);
1638 }
1639
1640 @Override
1641 public Class<?>[] exceptionTypes(MethodHandle handle) {
1642 return VarHandles.exceptionTypes(handle);
1643 }
1644
1645 @Override
1646 public MethodHandle serializableConstructor(Class<?> decl, Constructor<?> ctorToCall) throws IllegalAccessException {
1647 return IMPL_LOOKUP.serializableConstructor(decl, ctorToCall);
1648 }
1649
1650 });
1651 }
1652
1653 /** Result unboxing: ValueConversions.unbox() OR ValueConversions.identity() OR ValueConversions.ignore(). */
1654 private static MethodHandle unboxResultHandle(Class<?> returnType) {
1655 if (returnType.isPrimitive()) {
1656 if (returnType == void.class) {
1657 return ValueConversions.ignore();
1658 } else {
1659 Wrapper w = Wrapper.forPrimitiveType(returnType);
1660 return ValueConversions.unboxExact(w);
1661 }
1662 } else {
1663 return MethodHandles.identity(Object.class);
1664 }
1665 }
1666
1667 /**
1668 * Assembles a loop method handle from the given handles and type information.
1669 *
1670 * @param tloop the return type of the loop.
1671 * @param targs types of the arguments to be passed to the loop.
1672 * @param init sanitized array of initializers for loop-local variables.
1673 * @param step sanitized array of loop bodies.
1674 * @param pred sanitized array of predicates.
1675 * @param fini sanitized array of loop finalizers.
1676 *
1677 * @return a handle that, when invoked, will execute the loop.
1678 */
1679 static MethodHandle makeLoop(Class<?> tloop, List<Class<?>> targs, List<MethodHandle> init, List<MethodHandle> step,
1680 List<MethodHandle> pred, List<MethodHandle> fini) {
1681 MethodType type = MethodType.methodType(tloop, targs);
1682 BasicType[] initClauseTypes =
1683 init.stream().map(h -> h.type().returnType()).map(BasicType::basicType).toArray(BasicType[]::new);
1684 LambdaForm form = makeLoopForm(type.basicType(), initClauseTypes);
1685
1686 // Prepare auxiliary method handles used during LambdaForm interpretation.
1687 // Box arguments and wrap them into Object[]: ValueConversions.array().
1688 MethodType varargsType = type.changeReturnType(Object[].class);
1689 MethodHandle collectArgs = varargsArray(type.parameterCount()).asType(varargsType);
1690 MethodHandle unboxResult = unboxResultHandle(tloop);
1691
1692 LoopClauses clauseData =
1693 new LoopClauses(new MethodHandle[][]{toArray(init), toArray(step), toArray(pred), toArray(fini)});
1694 BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_LLL();
1695 BoundMethodHandle mh;
1696 try {
1697 mh = (BoundMethodHandle) data.factory().invokeBasic(type, form, (Object) clauseData,
1698 (Object) collectArgs, (Object) unboxResult);
1699 } catch (Throwable ex) {
1700 throw uncaughtException(ex);
1701 }
1702 assert(mh.type() == type);
1703 return mh;
1704 }
1705
1706 private static MethodHandle[] toArray(List<MethodHandle> l) {
1707 return l.toArray(new MethodHandle[0]);
1708 }
1709
1710 /**
1711 * Loops introduce some complexity as they can have additional local state. Hence, LambdaForms for loops are
1712 * generated from a template. The LambdaForm template shape for the loop combinator is as follows (assuming one
1713 * reference parameter passed in {@code a1}, and a reference return type, with the return value represented by
1714 * {@code t12}):
1715 * <blockquote><pre>{@code
1716 * loop=Lambda(a0:L,a1:L)=>{
1717 * t2:L=BoundMethodHandle$Species_L3.argL0(a0:L); // LoopClauses holding init, step, pred, fini handles
1718 * t3:L=BoundMethodHandle$Species_L3.argL1(a0:L); // helper handle to box the arguments into an Object[]
1719 * t4:L=BoundMethodHandle$Species_L3.argL2(a0:L); // helper handle to unbox the result
1720 * t5:L=MethodHandle.invokeBasic(t3:L,a1:L); // box the arguments into an Object[]
1721 * t6:L=MethodHandleImpl.loop(null,t2:L,t3:L); // call the loop executor
1722 * t7:L=MethodHandle.invokeBasic(t4:L,t6:L);t7:L} // unbox the result; return the result
1723 * }</pre></blockquote>
1724 * <p>
1725 * {@code argL0} is a LoopClauses instance holding, in a 2-dimensional array, the init, step, pred, and fini method
1726 * handles. {@code argL1} and {@code argL2} are auxiliary method handles: {@code argL1} boxes arguments and wraps
1727 * them into {@code Object[]} ({@code ValueConversions.array()}), and {@code argL2} unboxes the result if necessary
1728 * ({@code ValueConversions.unbox()}).
1729 * <p>
1730 * Having {@code t3} and {@code t4} passed in via a BMH and not hardcoded in the lambda form allows to share lambda
1731 * forms among loop combinators with the same basic type.
1732 * <p>
1733 * The above template is instantiated by using the {@link LambdaFormEditor} to replace the {@code null} argument to
1734 * the {@code loop} invocation with the {@code BasicType} array describing the loop clause types. This argument is
1735 * ignored in the loop invoker, but will be extracted and used in {@linkplain InvokerBytecodeGenerator#emitLoop(int)
1736 * bytecode generation}.
1737 */
1738 private static LambdaForm makeLoopForm(MethodType basicType, BasicType[] localVarTypes) {
1739 final int THIS_MH = 0; // the BMH_LLL
1740 final int ARG_BASE = 1; // start of incoming arguments
1741 final int ARG_LIMIT = ARG_BASE + basicType.parameterCount();
1742
1743 int nameCursor = ARG_LIMIT;
1744 final int GET_CLAUSE_DATA = nameCursor++;
1745 final int GET_COLLECT_ARGS = nameCursor++;
1746 final int GET_UNBOX_RESULT = nameCursor++;
1747 final int BOXED_ARGS = nameCursor++;
1748 final int LOOP = nameCursor++;
1749 final int UNBOX_RESULT = nameCursor++;
1750
1751 LambdaForm lform = basicType.form().cachedLambdaForm(MethodTypeForm.LF_LOOP);
1752 if (lform == null) {
1753 Name[] names = invokeArguments(nameCursor - ARG_LIMIT, basicType);
1754
1755 BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_LLL();
1756 names[THIS_MH] = names[THIS_MH].withConstraint(data);
1757 names[GET_CLAUSE_DATA] = new Name(data.getterFunction(0), names[THIS_MH]);
1758 names[GET_COLLECT_ARGS] = new Name(data.getterFunction(1), names[THIS_MH]);
1759 names[GET_UNBOX_RESULT] = new Name(data.getterFunction(2), names[THIS_MH]);
1760
1761 // t_{i}:L=MethodHandle.invokeBasic(collectArgs:L,a1:L,...);
1762 MethodType collectArgsType = basicType.changeReturnType(Object.class);
1763 MethodHandle invokeBasic = MethodHandles.basicInvoker(collectArgsType);
1764 Object[] args = new Object[invokeBasic.type().parameterCount()];
1765 args[0] = names[GET_COLLECT_ARGS];
1766 System.arraycopy(names, ARG_BASE, args, 1, ARG_LIMIT - ARG_BASE);
1767 names[BOXED_ARGS] = new Name(new NamedFunction(makeIntrinsic(invokeBasic, Intrinsic.LOOP)), args);
1768
1769 // t_{i+1}:L=MethodHandleImpl.loop(localTypes:L,clauses:L,t_{i}:L);
1770 Object[] lArgs =
1771 new Object[]{null, // placeholder for BasicType[] localTypes - will be added by LambdaFormEditor
1772 names[GET_CLAUSE_DATA], names[BOXED_ARGS]};
1773 names[LOOP] = new Name(getFunction(NF_loop), lArgs);
1774
1775 // t_{i+2}:I=MethodHandle.invokeBasic(unbox:L,t_{i+1}:L);
1776 MethodHandle invokeBasicUnbox = MethodHandles.basicInvoker(MethodType.methodType(basicType.rtype(), Object.class));
1777 Object[] unboxArgs = new Object[]{names[GET_UNBOX_RESULT], names[LOOP]};
1778 names[UNBOX_RESULT] = new Name(invokeBasicUnbox, unboxArgs);
1779
1780 lform = basicType.form().setCachedLambdaForm(MethodTypeForm.LF_LOOP,
1781 LambdaForm.create(basicType.parameterCount() + 1, names, Kind.LOOP));
1782 }
1783
1784 // BOXED_ARGS is the index into the names array where the loop idiom starts
1785 return lform.editor().noteLoopLocalTypesForm(BOXED_ARGS, localVarTypes);
1786 }
1787
1788 static class LoopClauses {
1789 @Stable final MethodHandle[][] clauses;
1790 LoopClauses(MethodHandle[][] clauses) {
1791 assert clauses.length == 4;
1792 this.clauses = clauses;
1793 }
1794 @Override
1795 public String toString() {
1796 StringBuilder sb = new StringBuilder("LoopClauses -- ");
1797 for (int i = 0; i < 4; ++i) {
1798 if (i > 0) {
1799 sb.append(" ");
1800 }
1801 sb.append('<').append(i).append(">: ");
1802 MethodHandle[] hs = clauses[i];
1803 for (int j = 0; j < hs.length; ++j) {
1804 if (j > 0) {
1805 sb.append(" ");
1806 }
1807 sb.append('*').append(j).append(": ").append(hs[j]).append('\n');
1808 }
1809 }
1810 sb.append(" --\n");
1811 return sb.toString();
1812 }
1813 }
1814
1815 /**
1816 * Intrinsified during LambdaForm compilation
1817 * (see {@link InvokerBytecodeGenerator#emitLoop(int)}).
1818 */
1819 @Hidden
1820 static Object loop(BasicType[] localTypes, LoopClauses clauseData, Object... av) throws Throwable {
1821 final MethodHandle[] init = clauseData.clauses[0];
1822 final MethodHandle[] step = clauseData.clauses[1];
1823 final MethodHandle[] pred = clauseData.clauses[2];
1824 final MethodHandle[] fini = clauseData.clauses[3];
1825 int varSize = (int) Stream.of(init).filter(h -> h.type().returnType() != void.class).count();
1826 int nArgs = init[0].type().parameterCount();
1827 Object[] varsAndArgs = new Object[varSize + nArgs];
1828 for (int i = 0, v = 0; i < init.length; ++i) {
1829 MethodHandle ih = init[i];
1830 if (ih.type().returnType() == void.class) {
1831 ih.invokeWithArguments(av);
1832 } else {
1833 varsAndArgs[v++] = ih.invokeWithArguments(av);
1834 }
1835 }
1836 System.arraycopy(av, 0, varsAndArgs, varSize, nArgs);
1837 final int nSteps = step.length;
1838 for (; ; ) {
1839 for (int i = 0, v = 0; i < nSteps; ++i) {
1840 MethodHandle p = pred[i];
1841 MethodHandle s = step[i];
1842 MethodHandle f = fini[i];
1843 if (s.type().returnType() == void.class) {
1844 s.invokeWithArguments(varsAndArgs);
1845 } else {
1846 varsAndArgs[v++] = s.invokeWithArguments(varsAndArgs);
1847 }
1848 if (!(boolean) p.invokeWithArguments(varsAndArgs)) {
1849 return f.invokeWithArguments(varsAndArgs);
1850 }
1851 }
1852 }
1853 }
1854
1855 /**
1856 * This method is bound as the predicate in {@linkplain MethodHandles#countedLoop(MethodHandle, MethodHandle,
1857 * MethodHandle) counting loops}.
1858 *
1859 * @param limit the upper bound of the parameter, statically bound at loop creation time.
1860 * @param counter the counter parameter, passed in during loop execution.
1861 *
1862 * @return whether the counter has reached the limit.
1863 */
1864 static boolean countedLoopPredicate(int limit, int counter) {
1865 return counter < limit;
1866 }
1867
1868 /**
1869 * This method is bound as the step function in {@linkplain MethodHandles#countedLoop(MethodHandle, MethodHandle,
1870 * MethodHandle) counting loops} to increment the counter.
1871 *
1872 * @param limit the upper bound of the loop counter (ignored).
1873 * @param counter the loop counter.
1874 *
1875 * @return the loop counter incremented by 1.
1876 */
1877 static int countedLoopStep(int limit, int counter) {
1878 return counter + 1;
1879 }
1880
1881 /**
1882 * This is bound to initialize the loop-local iterator in {@linkplain MethodHandles#iteratedLoop iterating loops}.
1883 *
1884 * @param it the {@link Iterable} over which the loop iterates.
1885 *
1886 * @return an {@link Iterator} over the argument's elements.
1887 */
1888 static Iterator<?> initIterator(Iterable<?> it) {
1889 return it.iterator();
1890 }
1891
1892 /**
1893 * This method is bound as the predicate in {@linkplain MethodHandles#iteratedLoop iterating loops}.
1894 *
1895 * @param it the iterator to be checked.
1896 *
1897 * @return {@code true} iff there are more elements to iterate over.
1898 */
1899 static boolean iteratePredicate(Iterator<?> it) {
1900 return it.hasNext();
1901 }
1902
1903 /**
1904 * This method is bound as the step for retrieving the current value from the iterator in {@linkplain
1905 * MethodHandles#iteratedLoop iterating loops}.
1906 *
1907 * @param it the iterator.
1908 *
1909 * @return the next element from the iterator.
1910 */
1911 static Object iterateNext(Iterator<?> it) {
1912 return it.next();
1913 }
1914
1915 /**
1916 * Makes a {@code try-finally} handle that conforms to the type constraints.
1917 *
1918 * @param target the target to execute in a {@code try-finally} block.
1919 * @param cleanup the cleanup to execute in the {@code finally} block.
1920 * @param rtype the result type of the entire construct.
1921 * @param argTypes the types of the arguments.
1922 *
1923 * @return a handle on the constructed {@code try-finally} block.
1924 */
1925 static MethodHandle makeTryFinally(MethodHandle target, MethodHandle cleanup, Class<?> rtype, Class<?>[] argTypes) {
1926 MethodType type = MethodType.methodType(rtype, argTypes);
1927 LambdaForm form = makeTryFinallyForm(type.basicType());
1928
1929 // Prepare auxiliary method handles used during LambdaForm interpretation.
1930 // Box arguments and wrap them into Object[]: ValueConversions.array().
1931 MethodType varargsType = type.changeReturnType(Object[].class);
1932 MethodHandle collectArgs = varargsArray(type.parameterCount()).asType(varargsType);
1933 MethodHandle unboxResult = unboxResultHandle(rtype);
1934
1935 BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_LLLL();
1936 BoundMethodHandle mh;
1937 try {
1938 mh = (BoundMethodHandle) data.factory().invokeBasic(type, form, (Object) target, (Object) cleanup,
1939 (Object) collectArgs, (Object) unboxResult);
1940 } catch (Throwable ex) {
1941 throw uncaughtException(ex);
1942 }
1943 assert(mh.type() == type);
1944 return mh;
1945 }
1946
1947 /**
1948 * The LambdaForm shape for the tryFinally combinator is as follows (assuming one reference parameter passed in
1949 * {@code a1}, and a reference return type, with the return value represented by {@code t8}):
1950 * <blockquote><pre>{@code
1951 * tryFinally=Lambda(a0:L,a1:L)=>{
1952 * t2:L=BoundMethodHandle$Species_LLLL.argL0(a0:L); // target method handle
1953 * t3:L=BoundMethodHandle$Species_LLLL.argL1(a0:L); // cleanup method handle
1954 * t4:L=BoundMethodHandle$Species_LLLL.argL2(a0:L); // helper handle to box the arguments into an Object[]
1955 * t5:L=BoundMethodHandle$Species_LLLL.argL3(a0:L); // helper handle to unbox the result
1956 * t6:L=MethodHandle.invokeBasic(t4:L,a1:L); // box the arguments into an Object[]
1957 * t7:L=MethodHandleImpl.tryFinally(t2:L,t3:L,t6:L); // call the tryFinally executor
1958 * t8:L=MethodHandle.invokeBasic(t5:L,t7:L);t8:L} // unbox the result; return the result
1959 * }</pre></blockquote>
1960 * <p>
1961 * {@code argL0} and {@code argL1} are the target and cleanup method handles.
1962 * {@code argL2} and {@code argL3} are auxiliary method handles: {@code argL2} boxes arguments and wraps them into
1963 * {@code Object[]} ({@code ValueConversions.array()}), and {@code argL3} unboxes the result if necessary
1964 * ({@code ValueConversions.unbox()}).
1965 * <p>
1966 * Having {@code t4} and {@code t5} passed in via a BMH and not hardcoded in the lambda form allows to share lambda
1967 * forms among tryFinally combinators with the same basic type.
1968 */
1969 private static LambdaForm makeTryFinallyForm(MethodType basicType) {
1970 LambdaForm lform = basicType.form().cachedLambdaForm(MethodTypeForm.LF_TF);
1971 if (lform != null) {
1972 return lform;
1973 }
1974 final int THIS_MH = 0; // the BMH_LLLL
1975 final int ARG_BASE = 1; // start of incoming arguments
1976 final int ARG_LIMIT = ARG_BASE + basicType.parameterCount();
1977
1978 int nameCursor = ARG_LIMIT;
1979 final int GET_TARGET = nameCursor++;
1980 final int GET_CLEANUP = nameCursor++;
1981 final int GET_COLLECT_ARGS = nameCursor++;
1982 final int GET_UNBOX_RESULT = nameCursor++;
1983 final int BOXED_ARGS = nameCursor++;
1984 final int TRY_FINALLY = nameCursor++;
1985 final int UNBOX_RESULT = nameCursor++;
1986
1987 Name[] names = invokeArguments(nameCursor - ARG_LIMIT, basicType);
1988
1989 BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_LLLL();
1990 names[THIS_MH] = names[THIS_MH].withConstraint(data);
1991 names[GET_TARGET] = new Name(data.getterFunction(0), names[THIS_MH]);
1992 names[GET_CLEANUP] = new Name(data.getterFunction(1), names[THIS_MH]);
1993 names[GET_COLLECT_ARGS] = new Name(data.getterFunction(2), names[THIS_MH]);
1994 names[GET_UNBOX_RESULT] = new Name(data.getterFunction(3), names[THIS_MH]);
1995
1996 // t_{i}:L=MethodHandle.invokeBasic(collectArgs:L,a1:L,...);
1997 MethodType collectArgsType = basicType.changeReturnType(Object.class);
1998 MethodHandle invokeBasic = MethodHandles.basicInvoker(collectArgsType);
1999 Object[] args = new Object[invokeBasic.type().parameterCount()];
2000 args[0] = names[GET_COLLECT_ARGS];
2001 System.arraycopy(names, ARG_BASE, args, 1, ARG_LIMIT-ARG_BASE);
2002 names[BOXED_ARGS] = new Name(new NamedFunction(makeIntrinsic(invokeBasic, Intrinsic.TRY_FINALLY)), args);
2003
2004 // t_{i+1}:L=MethodHandleImpl.tryFinally(target:L,exType:L,catcher:L,t_{i}:L);
2005 Object[] tfArgs = new Object[] {names[GET_TARGET], names[GET_CLEANUP], names[BOXED_ARGS]};
2006 names[TRY_FINALLY] = new Name(getFunction(NF_tryFinally), tfArgs);
2007
2008 // t_{i+2}:I=MethodHandle.invokeBasic(unbox:L,t_{i+1}:L);
2009 MethodHandle invokeBasicUnbox = MethodHandles.basicInvoker(MethodType.methodType(basicType.rtype(), Object.class));
2010 Object[] unboxArgs = new Object[] {names[GET_UNBOX_RESULT], names[TRY_FINALLY]};
2011 names[UNBOX_RESULT] = new Name(invokeBasicUnbox, unboxArgs);
2012
2013 lform = LambdaForm.create(basicType.parameterCount() + 1, names, Kind.TRY_FINALLY);
2014
2015 return basicType.form().setCachedLambdaForm(MethodTypeForm.LF_TF, lform);
2016 }
2017
2018 /**
2019 * Intrinsified during LambdaForm compilation
2020 * (see {@link InvokerBytecodeGenerator#emitTryFinally emitTryFinally}).
2021 */
2022 @Hidden
2023 static Object tryFinally(MethodHandle target, MethodHandle cleanup, Object... av) throws Throwable {
2024 Throwable t = null;
2025 Object r = null;
2026 try {
2027 r = target.invokeWithArguments(av);
2028 } catch (Throwable thrown) {
2029 t = thrown;
2030 throw t;
2031 } finally {
2032 Object[] args = target.type().returnType() == void.class ? prepend(av, t) : prepend(av, t, r);
2033 r = cleanup.invokeWithArguments(args);
2034 }
2035 return r;
2036 }
2037
2038 // see varargsArray method for chaching/package-private version of this
2039 private static MethodHandle makeCollector(Class<?> arrayType, int parameterCount) {
2040 MethodType type = MethodType.methodType(arrayType, Collections.nCopies(parameterCount, arrayType.componentType()));
2041 MethodHandle newArray = MethodHandles.arrayConstructor(arrayType);
2042
2043 LambdaForm form = makeCollectorForm(type.basicType(), arrayType);
2044
2045 BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_L();
2046 BoundMethodHandle mh;
2047 try {
2048 mh = (BoundMethodHandle) data.factory().invokeBasic(type, form, (Object) newArray);
2049 } catch (Throwable ex) {
2050 throw uncaughtException(ex);
2051 }
2052 assert(mh.type() == type);
2053 return mh;
2054 }
2055
2056 private static LambdaForm makeCollectorForm(MethodType basicType, Class<?> arrayType) {
2057 int parameterCount = basicType.parameterCount();
2058
2059 // Only share the lambda form for empty arrays and reference types.
2060 // Sharing based on the basic type alone doesn't work because
2061 // we need a separate lambda form for byte/short/char/int which
2062 // are all erased to int otherwise.
2063 // Other caching for primitive types happens at the MethodHandle level (see varargsArray).
2064 boolean isReferenceType = !arrayType.componentType().isPrimitive();
2065 boolean isSharedLambdaForm = parameterCount == 0 || isReferenceType;
2066 if (isSharedLambdaForm) {
2067 LambdaForm lform = basicType.form().cachedLambdaForm(MethodTypeForm.LF_COLLECTOR);
2068 if (lform != null) {
2069 return lform;
2070 }
2071 }
2072
2073 // use erased accessor for reference types
2074 MethodHandle storeFunc = isReferenceType
2075 ? ArrayAccessor.OBJECT_ARRAY_SETTER
2076 : makeArrayElementAccessor(arrayType, ArrayAccess.SET);
2077
2078 final int THIS_MH = 0; // the BMH_L
2079 final int ARG_BASE = 1; // start of incoming arguments
2080 final int ARG_LIMIT = ARG_BASE + parameterCount;
2081
2082 int nameCursor = ARG_LIMIT;
2083 final int GET_NEW_ARRAY = nameCursor++;
2084 final int CALL_NEW_ARRAY = nameCursor++;
2085 final int STORE_ELEMENT_BASE = nameCursor;
2086 final int STORE_ELEMENT_LIMIT = STORE_ELEMENT_BASE + parameterCount;
2087 nameCursor = STORE_ELEMENT_LIMIT;
2088
2089 Name[] names = invokeArguments(nameCursor - ARG_LIMIT, basicType);
2090
2091 BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_L();
2092 names[THIS_MH] = names[THIS_MH].withConstraint(data);
2093 names[GET_NEW_ARRAY] = new Name(data.getterFunction(0), names[THIS_MH]);
2094
2095 MethodHandle invokeBasic = MethodHandles.basicInvoker(MethodType.methodType(Object.class, int.class));
2096 names[CALL_NEW_ARRAY] = new Name(new NamedFunction(invokeBasic), names[GET_NEW_ARRAY], parameterCount);
2097 for (int storeIndex = 0,
2098 storeNameCursor = STORE_ELEMENT_BASE,
2099 argCursor = ARG_BASE;
2100 storeNameCursor < STORE_ELEMENT_LIMIT;
2101 storeIndex++, storeNameCursor++, argCursor++){
2102
2103 names[storeNameCursor] = new Name(new NamedFunction(makeIntrinsic(storeFunc, Intrinsic.ARRAY_STORE)),
2104 names[CALL_NEW_ARRAY], storeIndex, names[argCursor]);
2105 }
2106
2107 LambdaForm lform = LambdaForm.create(basicType.parameterCount() + 1, names, CALL_NEW_ARRAY, Kind.COLLECTOR);
2108 if (isSharedLambdaForm) {
2109 lform = basicType.form().setCachedLambdaForm(MethodTypeForm.LF_COLLECTOR, lform);
2110 }
2111 return lform;
2112 }
2113
2114 // use a wrapper because we need this array to be @Stable
2115 static class CasesHolder {
2116 @Stable
2117 final MethodHandle[] cases;
2118
2119 public CasesHolder(MethodHandle[] cases) {
2120 this.cases = cases;
2121 }
2122 }
2123
2124 static MethodHandle makeTableSwitch(MethodType type, MethodHandle defaultCase, MethodHandle[] caseActions) {
2125 MethodType varargsType = type.changeReturnType(Object[].class);
2126 MethodHandle collectArgs = varargsArray(type.parameterCount()).asType(varargsType);
2127
2128 MethodHandle unboxResult = unboxResultHandle(type.returnType());
2129
2130 BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_LLLL();
2131 LambdaForm form = makeTableSwitchForm(type.basicType(), data, caseActions.length);
2132 BoundMethodHandle mh;
2133 CasesHolder caseHolder = new CasesHolder(caseActions);
2134 try {
2135 mh = (BoundMethodHandle) data.factory().invokeBasic(type, form, (Object) defaultCase, (Object) collectArgs,
2136 (Object) unboxResult, (Object) caseHolder);
2137 } catch (Throwable ex) {
2138 throw uncaughtException(ex);
2139 }
2140 assert(mh.type() == type);
2141 return mh;
2142 }
2143
2144 private static class TableSwitchCacheKey {
2145 private static final Map<TableSwitchCacheKey, LambdaForm> CACHE = new ConcurrentHashMap<>();
2146
2147 private final MethodType basicType;
2148 private final int numberOfCases;
2149
2150 public TableSwitchCacheKey(MethodType basicType, int numberOfCases) {
2151 this.basicType = basicType;
2152 this.numberOfCases = numberOfCases;
2153 }
2154
2155 @Override
2156 public boolean equals(Object o) {
2157 if (this == o) return true;
2158 if (o == null || getClass() != o.getClass()) return false;
2159 TableSwitchCacheKey that = (TableSwitchCacheKey) o;
2160 return numberOfCases == that.numberOfCases && Objects.equals(basicType, that.basicType);
2161 }
2162 @Override
2163 public int hashCode() {
2164 return Objects.hash(basicType, numberOfCases);
2165 }
2166 }
2167
2168 private static LambdaForm makeTableSwitchForm(MethodType basicType, BoundMethodHandle.SpeciesData data,
2169 int numCases) {
2170 // We need to cache based on the basic type X number of cases,
2171 // since the number of cases is used when generating bytecode.
2172 // This also means that we can't use the cache in MethodTypeForm,
2173 // which only uses the basic type as a key.
2174 TableSwitchCacheKey key = new TableSwitchCacheKey(basicType, numCases);
2175 LambdaForm lform = TableSwitchCacheKey.CACHE.get(key);
2176 if (lform != null) {
2177 return lform;
2178 }
2179
2180 final int THIS_MH = 0;
2181 final int ARG_BASE = 1; // start of incoming arguments
2182 final int ARG_LIMIT = ARG_BASE + basicType.parameterCount();
2183 final int ARG_SWITCH_ON = ARG_BASE;
2184 assert ARG_SWITCH_ON < ARG_LIMIT;
2185
2186 int nameCursor = ARG_LIMIT;
2187 final int GET_COLLECT_ARGS = nameCursor++;
2188 final int GET_DEFAULT_CASE = nameCursor++;
2189 final int GET_UNBOX_RESULT = nameCursor++;
2190 final int GET_CASES = nameCursor++;
2191 final int BOXED_ARGS = nameCursor++;
2192 final int TABLE_SWITCH = nameCursor++;
2193 final int UNBOXED_RESULT = nameCursor++;
2194
2195 int fieldCursor = 0;
2196 final int FIELD_DEFAULT_CASE = fieldCursor++;
2197 final int FIELD_COLLECT_ARGS = fieldCursor++;
2198 final int FIELD_UNBOX_RESULT = fieldCursor++;
2199 final int FIELD_CASES = fieldCursor++;
2200
2201 Name[] names = invokeArguments(nameCursor - ARG_LIMIT, basicType);
2202
2203 names[THIS_MH] = names[THIS_MH].withConstraint(data);
2204 names[GET_DEFAULT_CASE] = new Name(data.getterFunction(FIELD_DEFAULT_CASE), names[THIS_MH]);
2205 names[GET_COLLECT_ARGS] = new Name(data.getterFunction(FIELD_COLLECT_ARGS), names[THIS_MH]);
2206 names[GET_UNBOX_RESULT] = new Name(data.getterFunction(FIELD_UNBOX_RESULT), names[THIS_MH]);
2207 names[GET_CASES] = new Name(data.getterFunction(FIELD_CASES), names[THIS_MH]);
2208
2209 {
2210 MethodType collectArgsType = basicType.changeReturnType(Object.class);
2211 MethodHandle invokeBasic = MethodHandles.basicInvoker(collectArgsType);
2212 Object[] args = new Object[invokeBasic.type().parameterCount()];
2213 args[0] = names[GET_COLLECT_ARGS];
2214 System.arraycopy(names, ARG_BASE, args, 1, ARG_LIMIT - ARG_BASE);
2215 names[BOXED_ARGS] = new Name(new NamedFunction(makeIntrinsic(invokeBasic, Intrinsic.TABLE_SWITCH, numCases)), args);
2216 }
2217
2218 {
2219 Object[] tfArgs = new Object[]{
2220 names[ARG_SWITCH_ON], names[GET_DEFAULT_CASE], names[GET_CASES], names[BOXED_ARGS]};
2221 names[TABLE_SWITCH] = new Name(getFunction(NF_tableSwitch), tfArgs);
2222 }
2223
2224 {
2225 MethodHandle invokeBasic = MethodHandles.basicInvoker(MethodType.methodType(basicType.rtype(), Object.class));
2226 Object[] unboxArgs = new Object[]{names[GET_UNBOX_RESULT], names[TABLE_SWITCH]};
2227 names[UNBOXED_RESULT] = new Name(invokeBasic, unboxArgs);
2228 }
2229
2230 lform = LambdaForm.create(basicType.parameterCount() + 1, names, Kind.TABLE_SWITCH);
2231 LambdaForm prev = TableSwitchCacheKey.CACHE.putIfAbsent(key, lform);
2232 return prev != null ? prev : lform;
2233 }
2234
2235 @Hidden
2236 static Object tableSwitch(int input, MethodHandle defaultCase, CasesHolder holder, Object[] args) throws Throwable {
2237 MethodHandle[] caseActions = holder.cases;
2238 MethodHandle selectedCase;
2239 if (input < 0 || input >= caseActions.length) {
2240 selectedCase = defaultCase;
2241 } else {
2242 selectedCase = caseActions[input];
2243 }
2244 return selectedCase.invokeWithArguments(args);
2245 }
2246
2247 // Indexes into constant method handles:
2248 static final int
2249 MH_cast = 0,
2250 MH_selectAlternative = 1,
2251 MH_countedLoopPred = 2,
2252 MH_countedLoopStep = 3,
2253 MH_initIterator = 4,
2254 MH_iteratePred = 5,
2255 MH_iterateNext = 6,
2256 MH_Array_newInstance = 7,
2257 MH_VarHandles_handleCheckedExceptions = 8,
2258 MH_LIMIT = 9;
2259
2260 static MethodHandle getConstantHandle(int idx) {
2261 MethodHandle handle = HANDLES[idx];
2262 if (handle != null) {
2263 return handle;
2264 }
2265 return setCachedHandle(idx, makeConstantHandle(idx));
2266 }
2267
2268 private static synchronized MethodHandle setCachedHandle(int idx, final MethodHandle method) {
2269 // Simulate a CAS, to avoid racy duplication of results.
2270 MethodHandle prev = HANDLES[idx];
2271 if (prev != null) {
2272 return prev;
2273 }
2274 HANDLES[idx] = method;
2275 return method;
2276 }
2277
2278 // Local constant method handles:
2279 private static final @Stable MethodHandle[] HANDLES = new MethodHandle[MH_LIMIT];
2280
2281 private static MethodHandle makeConstantHandle(int idx) {
2282 try {
2283 switch (idx) {
2284 case MH_cast:
2285 return IMPL_LOOKUP.findVirtual(Class.class, "cast",
2286 MethodType.methodType(Object.class, Object.class));
2287 case MH_selectAlternative:
2288 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "selectAlternative",
2289 MethodType.methodType(MethodHandle.class, boolean.class, MethodHandle.class, MethodHandle.class));
2290 case MH_countedLoopPred:
2291 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "countedLoopPredicate",
2292 MethodType.methodType(boolean.class, int.class, int.class));
2293 case MH_countedLoopStep:
2294 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "countedLoopStep",
2295 MethodType.methodType(int.class, int.class, int.class));
2296 case MH_initIterator:
2297 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "initIterator",
2298 MethodType.methodType(Iterator.class, Iterable.class));
2299 case MH_iteratePred:
2300 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "iteratePredicate",
2301 MethodType.methodType(boolean.class, Iterator.class));
2302 case MH_iterateNext:
2303 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "iterateNext",
2304 MethodType.methodType(Object.class, Iterator.class));
2305 case MH_Array_newInstance:
2306 return IMPL_LOOKUP.findStatic(Array.class, "newInstance",
2307 MethodType.methodType(Object.class, Class.class, int.class));
2308 case MH_VarHandles_handleCheckedExceptions:
2309 return IMPL_LOOKUP.findStatic(VarHandles.class, "handleCheckedExceptions",
2310 MethodType.methodType(void.class, Throwable.class));
2311 }
2312 } catch (ReflectiveOperationException ex) {
2313 throw newInternalError(ex);
2314 }
2315 throw newInternalError("Unknown function index: " + idx);
2316 }
2317 }