1 /*
2 * Copyright (c) 2008, 2013, 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 java.security.AccessController;
29 import java.security.PrivilegedAction;
30 import java.util.ArrayList;
31 import java.util.Arrays;
32 import java.util.Collections;
33
34 import sun.invoke.empty.Empty;
35 import sun.invoke.util.ValueConversions;
36 import sun.invoke.util.VerifyType;
37 import sun.invoke.util.Wrapper;
38 import sun.reflect.CallerSensitive;
39 import sun.reflect.Reflection;
40 import static java.lang.invoke.LambdaForm.*;
41 import static java.lang.invoke.MethodHandleStatics.*;
42 import static java.lang.invoke.MethodHandles.Lookup.IMPL_LOOKUP;
43
44 /**
45 * Trusted implementation code for MethodHandle.
46 * @author jrose
47 */
48 /*non-public*/ abstract class MethodHandleImpl {
49 // Do not adjust this except for special platforms:
50 private static final int MAX_ARITY;
51 static {
52 final Object[] values = { 255 };
53 AccessController.doPrivileged(new PrivilegedAction<Void>() {
54 @Override
55 public Void run() {
56 values[0] = Integer.getInteger(MethodHandleImpl.class.getName()+".MAX_ARITY", 255);
57 return null;
58 }
59 });
60 MAX_ARITY = (Integer) values[0];
61 }
62
63 /// Factory methods to create method handles:
64
65 static void initStatics() {
66 // Trigger selected static initializations.
67 MemberName.Factory.INSTANCE.getClass();
68 }
69
70 static MethodHandle makeArrayElementAccessor(Class<?> arrayClass, boolean isSetter) {
71 if (arrayClass == Object[].class)
72 return (isSetter ? ArrayAccessor.OBJECT_ARRAY_SETTER : ArrayAccessor.OBJECT_ARRAY_GETTER);
73 if (!arrayClass.isArray())
74 throw newIllegalArgumentException("not an array: "+arrayClass);
75 MethodHandle[] cache = ArrayAccessor.TYPED_ACCESSORS.get(arrayClass);
76 int cacheIndex = (isSetter ? ArrayAccessor.SETTER_INDEX : ArrayAccessor.GETTER_INDEX);
77 MethodHandle mh = cache[cacheIndex];
78 if (mh != null) return mh;
79 mh = ArrayAccessor.getAccessor(arrayClass, isSetter);
80 MethodType correctType = ArrayAccessor.correctType(arrayClass, isSetter);
81 if (mh.type() != correctType) {
82 assert(mh.type().parameterType(0) == Object[].class);
83 assert((isSetter ? mh.type().parameterType(2) : mh.type().returnType()) == Object.class);
84 assert(isSetter || correctType.parameterType(0).getComponentType() == correctType.returnType());
85 // safe to view non-strictly, because element type follows from array type
86 mh = mh.viewAsType(correctType, false);
87 }
88 mh = makeIntrinsic(mh, (isSetter ? Intrinsic.ARRAY_STORE : Intrinsic.ARRAY_LOAD));
89 // Atomically update accessor cache.
90 synchronized(cache) {
91 if (cache[cacheIndex] == null) {
92 cache[cacheIndex] = mh;
93 } else {
94 // Throw away newly constructed accessor and use cached version.
95 mh = cache[cacheIndex];
96 }
97 }
98 return mh;
99 }
100
101 static final class ArrayAccessor {
102 /// Support for array element access
103 static final int GETTER_INDEX = 0, SETTER_INDEX = 1, INDEX_LIMIT = 2;
104 static final ClassValue<MethodHandle[]> TYPED_ACCESSORS
105 = new ClassValue<MethodHandle[]>() {
106 @Override
107 protected MethodHandle[] computeValue(Class<?> type) {
108 return new MethodHandle[INDEX_LIMIT];
109 }
110 };
111 static final MethodHandle OBJECT_ARRAY_GETTER, OBJECT_ARRAY_SETTER;
112 static {
113 MethodHandle[] cache = TYPED_ACCESSORS.get(Object[].class);
114 cache[GETTER_INDEX] = OBJECT_ARRAY_GETTER = makeIntrinsic(getAccessor(Object[].class, false), Intrinsic.ARRAY_LOAD);
115 cache[SETTER_INDEX] = OBJECT_ARRAY_SETTER = makeIntrinsic(getAccessor(Object[].class, true), Intrinsic.ARRAY_STORE);
116
117 assert(InvokerBytecodeGenerator.isStaticallyInvocable(ArrayAccessor.OBJECT_ARRAY_GETTER.internalMemberName()));
118 assert(InvokerBytecodeGenerator.isStaticallyInvocable(ArrayAccessor.OBJECT_ARRAY_SETTER.internalMemberName()));
119 }
120
121 static int getElementI(int[] a, int i) { return a[i]; }
122 static long getElementJ(long[] a, int i) { return a[i]; }
123 static float getElementF(float[] a, int i) { return a[i]; }
124 static double getElementD(double[] a, int i) { return a[i]; }
125 static boolean getElementZ(boolean[] a, int i) { return a[i]; }
126 static byte getElementB(byte[] a, int i) { return a[i]; }
127 static short getElementS(short[] a, int i) { return a[i]; }
128 static char getElementC(char[] a, int i) { return a[i]; }
129 static Object getElementL(Object[] a, int i) { return a[i]; }
130
131 static void setElementI(int[] a, int i, int x) { a[i] = x; }
132 static void setElementJ(long[] a, int i, long x) { a[i] = x; }
133 static void setElementF(float[] a, int i, float x) { a[i] = x; }
134 static void setElementD(double[] a, int i, double x) { a[i] = x; }
135 static void setElementZ(boolean[] a, int i, boolean x) { a[i] = x; }
136 static void setElementB(byte[] a, int i, byte x) { a[i] = x; }
137 static void setElementS(short[] a, int i, short x) { a[i] = x; }
138 static void setElementC(char[] a, int i, char x) { a[i] = x; }
139 static void setElementL(Object[] a, int i, Object x) { a[i] = x; }
140
141 static String name(Class<?> arrayClass, boolean isSetter) {
142 Class<?> elemClass = arrayClass.getComponentType();
143 if (elemClass == null) throw newIllegalArgumentException("not an array", arrayClass);
144 return (!isSetter ? "getElement" : "setElement") + Wrapper.basicTypeChar(elemClass);
145 }
146 static MethodType type(Class<?> arrayClass, boolean isSetter) {
147 Class<?> elemClass = arrayClass.getComponentType();
148 Class<?> arrayArgClass = arrayClass;
149 if (!elemClass.isPrimitive()) {
150 arrayArgClass = Object[].class;
151 elemClass = Object.class;
152 }
153 return !isSetter ?
154 MethodType.methodType(elemClass, arrayArgClass, int.class) :
155 MethodType.methodType(void.class, arrayArgClass, int.class, elemClass);
156 }
157 static MethodType correctType(Class<?> arrayClass, boolean isSetter) {
158 Class<?> elemClass = arrayClass.getComponentType();
159 return !isSetter ?
160 MethodType.methodType(elemClass, arrayClass, int.class) :
161 MethodType.methodType(void.class, arrayClass, int.class, elemClass);
162 }
163 static MethodHandle getAccessor(Class<?> arrayClass, boolean isSetter) {
164 String name = name(arrayClass, isSetter);
165 MethodType type = type(arrayClass, isSetter);
166 try {
167 return IMPL_LOOKUP.findStatic(ArrayAccessor.class, name, type);
168 } catch (ReflectiveOperationException ex) {
169 throw uncaughtException(ex);
170 }
171 }
172 }
173
174 /**
175 * Create a JVM-level adapter method handle to conform the given method
176 * handle to the similar newType, using only pairwise argument conversions.
177 * For each argument, convert incoming argument to the exact type needed.
178 * The argument conversions allowed are casting, boxing and unboxing,
179 * integral widening or narrowing, and floating point widening or narrowing.
180 * @param srcType required call type
181 * @param target original method handle
182 * @param strict if true, only asType conversions are allowed; if false, explicitCastArguments conversions allowed
183 * @param monobox if true, unboxing conversions are assumed to be exactly typed (Integer to int only, not long or double)
184 * @return an adapter to the original handle with the desired new type,
185 * or the original target if the types are already identical
186 * or null if the adaptation cannot be made
187 */
188 static MethodHandle makePairwiseConvert(MethodHandle target, MethodType srcType,
189 boolean strict, boolean monobox) {
190 MethodType dstType = target.type();
191 if (srcType == dstType)
192 return target;
193 if (USE_LAMBDA_FORM_EDITOR) {
194 return makePairwiseConvertByEditor(target, srcType, strict, monobox);
195 } else {
196 return makePairwiseConvertIndirect(target, srcType, strict, monobox);
197 }
198 }
199
200 private static int countNonNull(Object[] array) {
201 int count = 0;
202 for (Object x : array) {
203 if (x != null) ++count;
204 }
205 return count;
206 }
207
208 static MethodHandle makePairwiseConvertByEditor(MethodHandle target, MethodType srcType,
209 boolean strict, boolean monobox) {
210 Object[] convSpecs = computeValueConversions(srcType, target.type(), strict, monobox);
211 int convCount = countNonNull(convSpecs);
212 if (convCount == 0)
213 return target.viewAsType(srcType, strict);
214 MethodType basicSrcType = srcType.basicType();
215 MethodType midType = target.type().basicType();
216 BoundMethodHandle mh = target.rebind();
217 // FIXME: Reduce number of bindings when there is more than one Class conversion.
218 // FIXME: Reduce number of bindings when there are repeated conversions.
219 for (int i = 0; i < convSpecs.length-1; i++) {
220 Object convSpec = convSpecs[i];
221 if (convSpec == null) continue;
222 MethodHandle fn;
223 if (convSpec instanceof Class) {
224 fn = Lazy.MH_castReference.bindTo(convSpec);
225 } else {
226 fn = (MethodHandle) convSpec;
227 }
228 Class<?> newType = basicSrcType.parameterType(i);
229 if (--convCount == 0)
230 midType = srcType;
231 else
232 midType = midType.changeParameterType(i, newType);
233 LambdaForm form2 = mh.editor().filterArgumentForm(1+i, BasicType.basicType(newType));
234 mh = mh.copyWithExtendL(midType, form2, fn);
235 mh = mh.rebind();
236 }
237 Object convSpec = convSpecs[convSpecs.length-1];
238 if (convSpec != null) {
239 MethodHandle fn;
240 if (convSpec instanceof Class) {
241 if (convSpec == void.class)
242 fn = null;
243 else
244 fn = Lazy.MH_castReference.bindTo(convSpec);
245 } else {
246 fn = (MethodHandle) convSpec;
247 }
248 Class<?> newType = basicSrcType.returnType();
249 assert(--convCount == 0);
250 midType = srcType;
251 if (fn != null) {
252 mh = mh.rebind(); // rebind if too complex
253 LambdaForm form2 = mh.editor().filterReturnForm(BasicType.basicType(newType), false);
254 mh = mh.copyWithExtendL(midType, form2, fn);
255 } else {
256 LambdaForm form2 = mh.editor().filterReturnForm(BasicType.basicType(newType), true);
257 mh = mh.copyWith(midType, form2);
258 }
259 }
260 assert(convCount == 0);
261 assert(mh.type().equals(srcType));
262 return mh;
263 }
264
265 static MethodHandle makePairwiseConvertIndirect(MethodHandle target, MethodType srcType,
266 boolean strict, boolean monobox) {
267 assert(target.type().parameterCount() == srcType.parameterCount());
268 // Calculate extra arguments (temporaries) required in the names array.
269 Object[] convSpecs = computeValueConversions(srcType, target.type(), strict, monobox);
270 final int INARG_COUNT = srcType.parameterCount();
271 int convCount = countNonNull(convSpecs);
272 boolean retConv = (convSpecs[INARG_COUNT] != null);
273 boolean retVoid = srcType.returnType() == void.class;
274 if (retConv && retVoid) {
275 convCount -= 1;
276 retConv = false;
277 }
278
279 final int IN_MH = 0;
280 final int INARG_BASE = 1;
281 final int INARG_LIMIT = INARG_BASE + INARG_COUNT;
282 final int NAME_LIMIT = INARG_LIMIT + convCount + 1;
283 final int RETURN_CONV = (!retConv ? -1 : NAME_LIMIT - 1);
284 final int OUT_CALL = (!retConv ? NAME_LIMIT : RETURN_CONV) - 1;
285 final int RESULT = (retVoid ? -1 : NAME_LIMIT - 1);
286
287 // Now build a LambdaForm.
288 MethodType lambdaType = srcType.basicType().invokerType();
289 Name[] names = arguments(NAME_LIMIT - INARG_LIMIT, lambdaType);
290
291 // Collect the arguments to the outgoing call, maybe with conversions:
292 final int OUTARG_BASE = 0; // target MH is Name.function, name Name.arguments[0]
293 Object[] outArgs = new Object[OUTARG_BASE + INARG_COUNT];
294
295 int nameCursor = INARG_LIMIT;
296 for (int i = 0; i < INARG_COUNT; i++) {
297 Object convSpec = convSpecs[i];
298 if (convSpec == null) {
299 // do nothing: difference is trivial
300 outArgs[OUTARG_BASE + i] = names[INARG_BASE + i];
301 continue;
302 }
303
304 Name conv;
305 if (convSpec instanceof Class) {
306 Class<?> convClass = (Class<?>) convSpec;
307 conv = new Name(Lazy.MH_castReference, convClass, names[INARG_BASE + i]);
308 } else {
309 MethodHandle fn = (MethodHandle) convSpec;
310 conv = new Name(fn, names[INARG_BASE + i]);
311 }
312 assert(names[nameCursor] == null);
313 names[nameCursor++] = conv;
314 assert(outArgs[OUTARG_BASE + i] == null);
315 outArgs[OUTARG_BASE + i] = conv;
316 }
317
318 // Build argument array for the call.
319 assert(nameCursor == OUT_CALL);
320 names[OUT_CALL] = new Name(target, outArgs);
321
322 Object convSpec = convSpecs[INARG_COUNT];
323 if (!retConv) {
324 assert(OUT_CALL == names.length-1);
325 } else {
326 Name conv;
327 if (convSpec == void.class) {
328 conv = new Name(LambdaForm.constantZero(BasicType.basicType(srcType.returnType())));
329 } else if (convSpec instanceof Class) {
330 Class<?> convClass = (Class<?>) convSpec;
331 conv = new Name(Lazy.MH_castReference, convClass, names[OUT_CALL]);
332 } else {
333 MethodHandle fn = (MethodHandle) convSpec;
334 if (fn.type().parameterCount() == 0)
335 conv = new Name(fn); // don't pass retval to void conversion
336 else
337 conv = new Name(fn, names[OUT_CALL]);
338 }
339 assert(names[RETURN_CONV] == null);
340 names[RETURN_CONV] = conv;
341 assert(RETURN_CONV == names.length-1);
342 }
343
344 LambdaForm form = new LambdaForm("convert", lambdaType.parameterCount(), names, RESULT);
345 return SimpleMethodHandle.make(srcType, form);
346 }
347
348 /**
349 * Identity function, with reference cast.
350 * @param t an arbitrary reference type
351 * @param x an arbitrary reference value
352 * @return the same value x
353 */
354 @ForceInline
355 @SuppressWarnings("unchecked")
356 static <T,U> T castReference(Class<? extends T> t, U x) {
357 // inlined Class.cast because we can't ForceInline it
358 if (x != null && !t.isInstance(x))
359 throw newClassCastException(t, x);
360 return (T) x;
361 }
362
363 private static ClassCastException newClassCastException(Class<?> t, Object obj) {
364 return new ClassCastException("Cannot cast " + obj.getClass().getName() + " to " + t.getName());
365 }
366
367 static Object[] computeValueConversions(MethodType srcType, MethodType dstType,
368 boolean strict, boolean monobox) {
369 final int INARG_COUNT = srcType.parameterCount();
370 Object[] convSpecs = new Object[INARG_COUNT+1];
371 for (int i = 0; i <= INARG_COUNT; i++) {
372 boolean isRet = (i == INARG_COUNT);
373 Class<?> src = isRet ? dstType.returnType() : srcType.parameterType(i);
374 Class<?> dst = isRet ? srcType.returnType() : dstType.parameterType(i);
375 if (!VerifyType.isNullConversion(src, dst, /*keepInterfaces=*/ strict)) {
376 convSpecs[i] = valueConversion(src, dst, strict, monobox);
377 }
378 }
379 return convSpecs;
380 }
381 static MethodHandle makePairwiseConvert(MethodHandle target, MethodType srcType,
382 boolean strict) {
383 return makePairwiseConvert(target, srcType, strict, /*monobox=*/ false);
384 }
385
386 /**
387 * Find a conversion function from the given source to the given destination.
388 * This conversion function will be used as a LF NamedFunction.
389 * Return a Class object if a simple cast is needed.
390 * Return void.class if void is involved.
391 */
392 static Object valueConversion(Class<?> src, Class<?> dst, boolean strict, boolean monobox) {
393 assert(!VerifyType.isNullConversion(src, dst, /*keepInterfaces=*/ strict)); // caller responsibility
394 if (dst == void.class)
395 return dst;
396 MethodHandle fn;
397 if (src.isPrimitive()) {
398 if (src == void.class) {
399 return void.class; // caller must recognize this specially
400 } else if (dst.isPrimitive()) {
401 // Examples: int->byte, byte->int, boolean->int (!strict)
402 fn = ValueConversions.convertPrimitive(src, dst);
403 } else {
404 // Examples: int->Integer, boolean->Object, float->Number
405 Wrapper wsrc = Wrapper.forPrimitiveType(src);
406 fn = ValueConversions.boxExact(wsrc);
407 assert(fn.type().parameterType(0) == wsrc.primitiveType());
408 assert(fn.type().returnType() == wsrc.wrapperType());
409 if (!VerifyType.isNullConversion(wsrc.wrapperType(), dst, strict)) {
410 // Corner case, such as int->Long, which will probably fail.
411 MethodType mt = MethodType.methodType(dst, src);
412 if (strict)
413 fn = fn.asType(mt);
414 else
415 fn = MethodHandleImpl.makePairwiseConvert(fn, mt, /*strict=*/ false);
416 }
417 }
418 } else if (dst.isPrimitive()) {
419 Wrapper wdst = Wrapper.forPrimitiveType(dst);
420 if (monobox || src == wdst.wrapperType()) {
421 // Use a strongly-typed unboxer, if possible.
422 fn = ValueConversions.unboxExact(wdst, strict);
423 } else {
424 // Examples: Object->int, Number->int, Comparable->int, Byte->int
425 // must include additional conversions
426 // src must be examined at runtime, to detect Byte, Character, etc.
427 fn = (strict
428 ? ValueConversions.unboxWiden(wdst)
429 : ValueConversions.unboxCast(wdst));
430 }
431 } else {
432 // Simple reference conversion.
433 // Note: Do not check for a class hierarchy relation
434 // between src and dst. In all cases a 'null' argument
435 // will pass the cast conversion.
436 return dst;
437 }
438 assert(fn.type().parameterCount() <= 1) : "pc"+Arrays.asList(src.getSimpleName(), dst.getSimpleName(), fn);
439 return fn;
440 }
441
442 static MethodHandle makeVarargsCollector(MethodHandle target, Class<?> arrayType) {
443 MethodType type = target.type();
444 int last = type.parameterCount() - 1;
445 if (type.parameterType(last) != arrayType)
446 target = target.asType(type.changeParameterType(last, arrayType));
447 target = target.asFixedArity(); // make sure this attribute is turned off
448 return new AsVarargsCollector(target, arrayType);
449 }
450
451 private static final class AsVarargsCollector extends DelegatingMethodHandle {
452 private final MethodHandle target;
453 private final Class<?> arrayType;
454 private @Stable MethodHandle asCollectorCache;
455
456 AsVarargsCollector(MethodHandle target, Class<?> arrayType) {
457 this(target.type(), target, arrayType);
458 }
459 AsVarargsCollector(MethodType type, MethodHandle target, Class<?> arrayType) {
460 super(type, target);
461 this.target = target;
462 this.arrayType = arrayType;
463 this.asCollectorCache = target.asCollector(arrayType, 0);
464 }
465
466 @Override
467 public boolean isVarargsCollector() {
468 return true;
469 }
470
471 @Override
472 protected MethodHandle getTarget() {
473 return target;
474 }
475
476 @Override
477 public MethodHandle asFixedArity() {
478 return target;
479 }
480
481 @Override
482 MethodHandle setVarargs(MemberName member) {
483 if (member.isVarargs()) return this;
484 return asFixedArity();
485 }
486
487 @Override
488 public MethodHandle asTypeUncached(MethodType newType) {
489 MethodType type = this.type();
490 int collectArg = type.parameterCount() - 1;
491 int newArity = newType.parameterCount();
492 if (newArity == collectArg+1 &&
493 type.parameterType(collectArg).isAssignableFrom(newType.parameterType(collectArg))) {
494 // if arity and trailing parameter are compatible, do normal thing
495 return asTypeCache = asFixedArity().asType(newType);
496 }
497 // check cache
498 MethodHandle acc = asCollectorCache;
499 if (acc != null && acc.type().parameterCount() == newArity)
500 return asTypeCache = acc.asType(newType);
501 // build and cache a collector
502 int arrayLength = newArity - collectArg;
503 MethodHandle collector;
504 try {
505 collector = asFixedArity().asCollector(arrayType, arrayLength);
506 assert(collector.type().parameterCount() == newArity) : "newArity="+newArity+" but collector="+collector;
507 } catch (IllegalArgumentException ex) {
508 throw new WrongMethodTypeException("cannot build collector", ex);
509 }
510 asCollectorCache = collector;
511 return asTypeCache = collector.asType(newType);
512 }
513
514 @Override
515 boolean viewAsTypeChecks(MethodType newType, boolean strict) {
516 super.viewAsTypeChecks(newType, true);
517 if (strict) return true;
518 // extra assertion for non-strict checks:
519 assert (type().lastParameterType().getComponentType()
520 .isAssignableFrom(
521 newType.lastParameterType().getComponentType()))
522 : Arrays.asList(this, newType);
523 return true;
524 }
525 }
526
527 /** Factory method: Spread selected argument. */
528 static MethodHandle makeSpreadArguments(MethodHandle target,
529 Class<?> spreadArgType, int spreadArgPos, int spreadArgCount) {
530 MethodType targetType = target.type();
531
532 for (int i = 0; i < spreadArgCount; i++) {
533 Class<?> arg = VerifyType.spreadArgElementType(spreadArgType, i);
534 if (arg == null) arg = Object.class;
535 targetType = targetType.changeParameterType(spreadArgPos + i, arg);
536 }
537 target = target.asType(targetType);
538
539 MethodType srcType = targetType
540 .replaceParameterTypes(spreadArgPos, spreadArgPos + spreadArgCount, spreadArgType);
541 // Now build a LambdaForm.
542 MethodType lambdaType = srcType.invokerType();
543 Name[] names = arguments(spreadArgCount + 2, lambdaType);
544 int nameCursor = lambdaType.parameterCount();
545 int[] indexes = new int[targetType.parameterCount()];
546
547 for (int i = 0, argIndex = 1; i < targetType.parameterCount() + 1; i++, argIndex++) {
548 Class<?> src = lambdaType.parameterType(i);
549 if (i == spreadArgPos) {
550 // Spread the array.
551 MethodHandle aload = MethodHandles.arrayElementGetter(spreadArgType);
552 Name array = names[argIndex];
553 names[nameCursor++] = new Name(Lazy.NF_checkSpreadArgument, array, spreadArgCount);
554 for (int j = 0; j < spreadArgCount; i++, j++) {
555 indexes[i] = nameCursor;
556 names[nameCursor++] = new Name(aload, array, j);
557 }
558 } else if (i < indexes.length) {
559 indexes[i] = argIndex;
560 }
561 }
562 assert(nameCursor == names.length-1); // leave room for the final call
563
564 // Build argument array for the call.
565 Name[] targetArgs = new Name[targetType.parameterCount()];
566 for (int i = 0; i < targetType.parameterCount(); i++) {
567 int idx = indexes[i];
568 targetArgs[i] = names[idx];
569 }
570 names[names.length - 1] = new Name(target, (Object[]) targetArgs);
571
572 LambdaForm form = new LambdaForm("spread", lambdaType.parameterCount(), names);
573 return SimpleMethodHandle.make(srcType, form);
574 }
575
576 static void checkSpreadArgument(Object av, int n) {
577 if (av == null) {
578 if (n == 0) return;
579 } else if (av instanceof Object[]) {
580 int len = ((Object[])av).length;
581 if (len == n) return;
582 } else {
583 int len = java.lang.reflect.Array.getLength(av);
584 if (len == n) return;
585 }
586 // fall through to error:
587 throw newIllegalArgumentException("array is not of length "+n);
588 }
589
590 /**
591 * Pre-initialized NamedFunctions for bootstrapping purposes.
592 * Factored in an inner class to delay initialization until first usage.
593 */
594 static class Lazy {
595 private static final Class<?> MHI = MethodHandleImpl.class;
596
597 static final NamedFunction NF_checkSpreadArgument;
598 static final NamedFunction NF_guardWithCatch;
599 static final NamedFunction NF_throwException;
600
601 static final MethodHandle MH_castReference;
602 static final MethodHandle MH_selectAlternative;
603 static final MethodHandle MH_copyAsPrimitiveArray;
604 static final MethodHandle MH_fillNewTypedArray;
605 static final MethodHandle MH_fillNewArray;
606 static final MethodHandle MH_arrayIdentity;
607
608 static {
609 try {
610 NF_checkSpreadArgument = new NamedFunction(MHI.getDeclaredMethod("checkSpreadArgument", Object.class, int.class));
611 NF_guardWithCatch = new NamedFunction(MHI.getDeclaredMethod("guardWithCatch", MethodHandle.class, Class.class,
612 MethodHandle.class, Object[].class));
613 NF_throwException = new NamedFunction(MHI.getDeclaredMethod("throwException", Throwable.class));
614
615 NF_checkSpreadArgument.resolve();
616 NF_guardWithCatch.resolve();
617 NF_throwException.resolve();
618
619 MH_castReference = IMPL_LOOKUP.findStatic(MHI, "castReference",
620 MethodType.methodType(Object.class, Class.class, Object.class));
621 MH_copyAsPrimitiveArray = IMPL_LOOKUP.findStatic(MHI, "copyAsPrimitiveArray",
622 MethodType.methodType(Object.class, Wrapper.class, Object[].class));
623 MH_arrayIdentity = IMPL_LOOKUP.findStatic(MHI, "identity",
624 MethodType.methodType(Object[].class, Object[].class));
625 MH_fillNewArray = IMPL_LOOKUP.findStatic(MHI, "fillNewArray",
626 MethodType.methodType(Object[].class, Integer.class, Object[].class));
627 MH_fillNewTypedArray = IMPL_LOOKUP.findStatic(MHI, "fillNewTypedArray",
628 MethodType.methodType(Object[].class, Object[].class, Integer.class, Object[].class));
629
630 MH_selectAlternative = makeIntrinsic(
631 IMPL_LOOKUP.findStatic(MHI, "selectAlternative",
632 MethodType.methodType(MethodHandle.class, boolean.class, MethodHandle.class, MethodHandle.class)),
633 Intrinsic.SELECT_ALTERNATIVE);
634 } catch (ReflectiveOperationException ex) {
635 throw newInternalError(ex);
636 }
637 }
638 }
639
640 /** Factory method: Collect or filter selected argument(s). */
641 static MethodHandle makeCollectArguments(MethodHandle target,
642 MethodHandle collector, int collectArgPos, boolean retainOriginalArgs) {
643 MethodType targetType = target.type(); // (a..., c, [b...])=>r
644 MethodType collectorType = collector.type(); // (b...)=>c
645 int collectArgCount = collectorType.parameterCount();
646 Class<?> collectValType = collectorType.returnType();
647 int collectValCount = (collectValType == void.class ? 0 : 1);
648 MethodType srcType = targetType // (a..., [b...])=>r
649 .dropParameterTypes(collectArgPos, collectArgPos+collectValCount);
650 if (!retainOriginalArgs) { // (a..., b...)=>r
651 srcType = srcType.insertParameterTypes(collectArgPos, collectorType.parameterList());
652 }
653 // in arglist: [0: ...keep1 | cpos: collect... | cpos+cacount: keep2... ]
654 // out arglist: [0: ...keep1 | cpos: collectVal? | cpos+cvcount: keep2... ]
655 // out(retain): [0: ...keep1 | cpos: cV? coll... | cpos+cvc+cac: keep2... ]
656
657 // Now build a LambdaForm.
658 MethodType lambdaType = srcType.invokerType();
659 Name[] names = arguments(2, lambdaType);
660 final int collectNamePos = names.length - 2;
661 final int targetNamePos = names.length - 1;
662
663 Name[] collectorArgs = Arrays.copyOfRange(names, 1 + collectArgPos, 1 + collectArgPos + collectArgCount);
664 names[collectNamePos] = new Name(collector, (Object[]) collectorArgs);
665
666 // Build argument array for the target.
667 // Incoming LF args to copy are: [ (mh) headArgs collectArgs tailArgs ].
668 // Output argument array is [ headArgs (collectVal)? (collectArgs)? tailArgs ].
669 Name[] targetArgs = new Name[targetType.parameterCount()];
670 int inputArgPos = 1; // incoming LF args to copy to target
671 int targetArgPos = 0; // fill pointer for targetArgs
672 int chunk = collectArgPos; // |headArgs|
673 System.arraycopy(names, inputArgPos, targetArgs, targetArgPos, chunk);
674 inputArgPos += chunk;
675 targetArgPos += chunk;
676 if (collectValType != void.class) {
677 targetArgs[targetArgPos++] = names[collectNamePos];
678 }
679 chunk = collectArgCount;
680 if (retainOriginalArgs) {
681 System.arraycopy(names, inputArgPos, targetArgs, targetArgPos, chunk);
682 targetArgPos += chunk; // optionally pass on the collected chunk
683 }
684 inputArgPos += chunk;
685 chunk = targetArgs.length - targetArgPos; // all the rest
686 System.arraycopy(names, inputArgPos, targetArgs, targetArgPos, chunk);
687 assert(inputArgPos + chunk == collectNamePos); // use of rest of input args also
688 names[targetNamePos] = new Name(target, (Object[]) targetArgs);
689
690 LambdaForm form = new LambdaForm("collect", lambdaType.parameterCount(), names);
691 return SimpleMethodHandle.make(srcType, form);
692 }
693
694 @LambdaForm.Hidden
695 static
696 MethodHandle selectAlternative(boolean testResult, MethodHandle target, MethodHandle fallback) {
697 return testResult ? target : fallback;
698 }
699
700 static
701 MethodHandle makeGuardWithTest(MethodHandle test,
702 MethodHandle target,
703 MethodHandle fallback) {
704 MethodType type = target.type();
705 assert(test.type().equals(type.changeReturnType(boolean.class)) && fallback.type().equals(type));
706 MethodType basicType = type.basicType();
707 LambdaForm form = makeGuardWithTestForm(basicType);
708 BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_LLL();
709 BoundMethodHandle mh;
710
711 try {
712 mh = (BoundMethodHandle)
713 data.constructor().invokeBasic(type, form,
714 (Object) test, (Object) profile(target), (Object) profile(fallback));
715 } catch (Throwable ex) {
716 throw uncaughtException(ex);
717 }
718 assert(mh.type() == type);
719 return mh;
720 }
721
722
723 static
724 MethodHandle profile(MethodHandle target) {
725 if (DONT_INLINE_THRESHOLD > 0) {
726 return BlockInliningWrapper.make(target);
727 } else {
728 return target;
729 }
730 }
731
732 /**
733 * Block inlining during JIT-compilation of a target method handle if it hasn't been invoked enough times.
734 * Corresponding LambdaForm has @DontInline when compiled into bytecode.
735 */
736 static class BlockInliningWrapper extends DelegatingMethodHandle {
737 private final MethodHandle target;
738 private int count;
739 private volatile boolean isActivated = true;
740
741 private BlockInliningWrapper(MethodHandle target, LambdaForm lform, int count) {
742 super(target.type(), lform);
743 this.target = target;
744 this.count = count;
745 }
746
747 @Hidden
748 @Override
749 protected MethodHandle getTarget() {
750 return target;
751 }
752
753 @Override
754 public MethodHandle asTypeUncached(MethodType newType) {
755 MethodHandle newTarget = target.asType(newType);
756 return asTypeCache = isActivated ? make(newTarget)
757 : newTarget; // no need for a wrapper anymore
758 }
759
760 boolean unblock() {
761 if (count <= 0) {
762 // Try to limit number of updates. MethodHandle.updateForm() doesn't guarantee LF update visibility.
763 if (isActivated) {
764 isActivated = false;
765 return true;
766 } else {
767 return false;
768 }
769 } else {
770 --count;
771 return false;
772 }
773 }
774
775 static MethodHandle make(MethodHandle target) {
776 LambdaForm lform = DelegatingMethodHandle.makeReinvokerForm(target,
777 MethodTypeForm.LF_DELEGATE_COUNTING, BlockInliningWrapper.class, "reinvoker.dontInline", false,
778 DelegatingMethodHandle.NF_getTarget, NF_maybeUnblock);
779 MethodHandle wrapper = new BlockInliningWrapper(target, lform, DONT_INLINE_THRESHOLD);
780 return wrapper;
781 }
782
783 @Hidden
784 static void maybeUnblock(Object o1) {
785 BlockInliningWrapper wrapper = (BlockInliningWrapper) o1;
786 if (wrapper.unblock()) {
787 // Reached invocation threshold. Replace counting/blocking wrapper with a reinvoker.
788 wrapper.isActivated = false;
789 MethodHandle target = wrapper.getTarget();
790 LambdaForm lform = DelegatingMethodHandle.makeReinvokerForm(
791 target, MethodTypeForm.LF_DELEGATE, DelegatingMethodHandle.class, NF_getTarget);
792 wrapper.updateForm(lform);
793 }
794 }
795
796 static final NamedFunction NF_maybeUnblock;
797 static {
798 Class<?> THIS_CLASS = BlockInliningWrapper.class;
799 try {
800 NF_maybeUnblock = new NamedFunction(THIS_CLASS.getDeclaredMethod("maybeUnblock", Object.class));
801 } catch (ReflectiveOperationException ex) {
802 throw newInternalError(ex);
803 }
804 }
805 }
806
807 static
808 LambdaForm makeGuardWithTestForm(MethodType basicType) {
809 LambdaForm lform = basicType.form().cachedLambdaForm(MethodTypeForm.LF_GWT);
810 if (lform != null) return lform;
811 final int THIS_MH = 0; // the BMH_LLL
812 final int ARG_BASE = 1; // start of incoming arguments
813 final int ARG_LIMIT = ARG_BASE + basicType.parameterCount();
814 int nameCursor = ARG_LIMIT;
815 final int GET_TEST = nameCursor++;
816 final int GET_TARGET = nameCursor++;
817 final int GET_FALLBACK = nameCursor++;
818 final int CALL_TEST = nameCursor++;
819 final int SELECT_ALT = nameCursor++;
820 final int CALL_TARGET = nameCursor++;
821 assert(CALL_TARGET == SELECT_ALT+1); // must be true to trigger IBG.emitSelectAlternative
822
823 MethodType lambdaType = basicType.invokerType();
824 Name[] names = arguments(nameCursor - ARG_LIMIT, lambdaType);
825
826 BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_LLL();
827 names[THIS_MH] = names[THIS_MH].withConstraint(data);
828 names[GET_TEST] = new Name(data.getterFunction(0), names[THIS_MH]);
829 names[GET_TARGET] = new Name(data.getterFunction(1), names[THIS_MH]);
830 names[GET_FALLBACK] = new Name(data.getterFunction(2), names[THIS_MH]);
831
832 Object[] invokeArgs = Arrays.copyOfRange(names, 0, ARG_LIMIT, Object[].class);
833
834 // call test
835 MethodType testType = basicType.changeReturnType(boolean.class).basicType();
836 invokeArgs[0] = names[GET_TEST];
837 names[CALL_TEST] = new Name(testType, invokeArgs);
838
839 // call selectAlternative
840 names[SELECT_ALT] = new Name(Lazy.MH_selectAlternative, names[CALL_TEST],
841 names[GET_TARGET], names[GET_FALLBACK]);
842
843 // call target or fallback
844 invokeArgs[0] = names[SELECT_ALT];
845 names[CALL_TARGET] = new Name(basicType, invokeArgs);
846
847 lform = new LambdaForm("guard", lambdaType.parameterCount(), names);
848
849 return basicType.form().setCachedLambdaForm(MethodTypeForm.LF_GWT, lform);
850 }
851
852 /**
853 * The LambdaForm shape for catchException combinator is the following:
854 * <blockquote><pre>{@code
855 * guardWithCatch=Lambda(a0:L,a1:L,a2:L)=>{
856 * t3:L=BoundMethodHandle$Species_LLLLL.argL0(a0:L);
857 * t4:L=BoundMethodHandle$Species_LLLLL.argL1(a0:L);
858 * t5:L=BoundMethodHandle$Species_LLLLL.argL2(a0:L);
859 * t6:L=BoundMethodHandle$Species_LLLLL.argL3(a0:L);
860 * t7:L=BoundMethodHandle$Species_LLLLL.argL4(a0:L);
861 * t8:L=MethodHandle.invokeBasic(t6:L,a1:L,a2:L);
862 * t9:L=MethodHandleImpl.guardWithCatch(t3:L,t4:L,t5:L,t8:L);
863 * t10:I=MethodHandle.invokeBasic(t7:L,t9:L);t10:I}
864 * }</pre></blockquote>
865 *
866 * argL0 and argL2 are target and catcher method handles. argL1 is exception class.
867 * argL3 and argL4 are auxiliary method handles: argL3 boxes arguments and wraps them into Object[]
868 * (ValueConversions.array()) and argL4 unboxes result if necessary (ValueConversions.unbox()).
869 *
870 * Having t8 and t10 passed outside and not hardcoded into a lambda form allows to share lambda forms
871 * among catchException combinators with the same basic type.
872 */
873 private static LambdaForm makeGuardWithCatchForm(MethodType basicType) {
874 MethodType lambdaType = basicType.invokerType();
875
876 LambdaForm lform = basicType.form().cachedLambdaForm(MethodTypeForm.LF_GWC);
877 if (lform != null) {
878 return lform;
879 }
880 final int THIS_MH = 0; // the BMH_LLLLL
881 final int ARG_BASE = 1; // start of incoming arguments
882 final int ARG_LIMIT = ARG_BASE + basicType.parameterCount();
883
884 int nameCursor = ARG_LIMIT;
885 final int GET_TARGET = nameCursor++;
886 final int GET_CLASS = nameCursor++;
887 final int GET_CATCHER = nameCursor++;
888 final int GET_COLLECT_ARGS = nameCursor++;
889 final int GET_UNBOX_RESULT = nameCursor++;
890 final int BOXED_ARGS = nameCursor++;
891 final int TRY_CATCH = nameCursor++;
892 final int UNBOX_RESULT = nameCursor++;
893
894 Name[] names = arguments(nameCursor - ARG_LIMIT, lambdaType);
895
896 BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_LLLLL();
897 names[THIS_MH] = names[THIS_MH].withConstraint(data);
898 names[GET_TARGET] = new Name(data.getterFunction(0), names[THIS_MH]);
899 names[GET_CLASS] = new Name(data.getterFunction(1), names[THIS_MH]);
900 names[GET_CATCHER] = new Name(data.getterFunction(2), names[THIS_MH]);
901 names[GET_COLLECT_ARGS] = new Name(data.getterFunction(3), names[THIS_MH]);
902 names[GET_UNBOX_RESULT] = new Name(data.getterFunction(4), names[THIS_MH]);
903
904 // FIXME: rework argument boxing/result unboxing logic for LF interpretation
905
906 // t_{i}:L=MethodHandle.invokeBasic(collectArgs:L,a1:L,...);
907 MethodType collectArgsType = basicType.changeReturnType(Object.class);
908 MethodHandle invokeBasic = MethodHandles.basicInvoker(collectArgsType);
909 Object[] args = new Object[invokeBasic.type().parameterCount()];
910 args[0] = names[GET_COLLECT_ARGS];
911 System.arraycopy(names, ARG_BASE, args, 1, ARG_LIMIT-ARG_BASE);
912 names[BOXED_ARGS] = new Name(makeIntrinsic(invokeBasic, Intrinsic.GUARD_WITH_CATCH), args);
913
914 // t_{i+1}:L=MethodHandleImpl.guardWithCatch(target:L,exType:L,catcher:L,t_{i}:L);
915 Object[] gwcArgs = new Object[] {names[GET_TARGET], names[GET_CLASS], names[GET_CATCHER], names[BOXED_ARGS]};
916 names[TRY_CATCH] = new Name(Lazy.NF_guardWithCatch, gwcArgs);
917
918 // t_{i+2}:I=MethodHandle.invokeBasic(unbox:L,t_{i+1}:L);
919 MethodHandle invokeBasicUnbox = MethodHandles.basicInvoker(MethodType.methodType(basicType.rtype(), Object.class));
920 Object[] unboxArgs = new Object[] {names[GET_UNBOX_RESULT], names[TRY_CATCH]};
921 names[UNBOX_RESULT] = new Name(invokeBasicUnbox, unboxArgs);
922
923 lform = new LambdaForm("guardWithCatch", lambdaType.parameterCount(), names);
924
925 return basicType.form().setCachedLambdaForm(MethodTypeForm.LF_GWC, lform);
926 }
927
928 static
929 MethodHandle makeGuardWithCatch(MethodHandle target,
930 Class<? extends Throwable> exType,
931 MethodHandle catcher) {
932 MethodType type = target.type();
933 LambdaForm form = makeGuardWithCatchForm(type.basicType());
934
935 // Prepare auxiliary method handles used during LambdaForm interpretation.
936 // Box arguments and wrap them into Object[]: ValueConversions.array().
937 MethodType varargsType = type.changeReturnType(Object[].class);
938 MethodHandle collectArgs = varargsArray(type.parameterCount()).asType(varargsType);
939 // Result unboxing: ValueConversions.unbox() OR ValueConversions.identity() OR ValueConversions.ignore().
940 MethodHandle unboxResult;
941 Class<?> rtype = type.returnType();
942 if (rtype.isPrimitive()) {
943 if (rtype == void.class) {
944 unboxResult = ValueConversions.ignore();
945 } else {
946 Wrapper w = Wrapper.forPrimitiveType(type.returnType());
947 unboxResult = ValueConversions.unboxExact(w);
948 }
949 } else {
950 unboxResult = MethodHandles.identity(Object.class);
951 }
952
953 BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_LLLLL();
954 BoundMethodHandle mh;
955 try {
956 mh = (BoundMethodHandle)
957 data.constructor().invokeBasic(type, form, (Object) target, (Object) exType, (Object) catcher,
958 (Object) collectArgs, (Object) unboxResult);
959 } catch (Throwable ex) {
960 throw uncaughtException(ex);
961 }
962 assert(mh.type() == type);
963 return mh;
964 }
965
966 /**
967 * Intrinsified during LambdaForm compilation
968 * (see {@link InvokerBytecodeGenerator#emitGuardWithCatch emitGuardWithCatch}).
969 */
970 @LambdaForm.Hidden
971 static Object guardWithCatch(MethodHandle target, Class<? extends Throwable> exType, MethodHandle catcher,
972 Object... av) throws Throwable {
973 // Use asFixedArity() to avoid unnecessary boxing of last argument for VarargsCollector case.
974 try {
975 return target.asFixedArity().invokeWithArguments(av);
976 } catch (Throwable t) {
977 if (!exType.isInstance(t)) throw t;
978 return catcher.asFixedArity().invokeWithArguments(prepend(t, av));
979 }
980 }
981
982 /** Prepend an element {@code elem} to an {@code array}. */
983 @LambdaForm.Hidden
984 private static Object[] prepend(Object elem, Object[] array) {
985 Object[] newArray = new Object[array.length+1];
986 newArray[0] = elem;
987 System.arraycopy(array, 0, newArray, 1, array.length);
988 return newArray;
989 }
990
991 static
992 MethodHandle throwException(MethodType type) {
993 assert(Throwable.class.isAssignableFrom(type.parameterType(0)));
994 int arity = type.parameterCount();
995 if (arity > 1) {
996 MethodHandle mh = throwException(type.dropParameterTypes(1, arity));
997 mh = MethodHandles.dropArguments(mh, 1, type.parameterList().subList(1, arity));
998 return mh;
999 }
1000 return makePairwiseConvert(Lazy.NF_throwException.resolvedHandle(), type, false, true);
1001 }
1002
1003 static <T extends Throwable> Empty throwException(T t) throws T { throw t; }
1004
1005 static MethodHandle[] FAKE_METHOD_HANDLE_INVOKE = new MethodHandle[2];
1006 static MethodHandle fakeMethodHandleInvoke(MemberName method) {
1007 int idx;
1008 assert(method.isMethodHandleInvoke());
1009 switch (method.getName()) {
1010 case "invoke": idx = 0; break;
1011 case "invokeExact": idx = 1; break;
1012 default: throw new InternalError(method.getName());
1013 }
1014 MethodHandle mh = FAKE_METHOD_HANDLE_INVOKE[idx];
1015 if (mh != null) return mh;
1016 MethodType type = MethodType.methodType(Object.class, UnsupportedOperationException.class,
1017 MethodHandle.class, Object[].class);
1018 mh = throwException(type);
1019 mh = mh.bindTo(new UnsupportedOperationException("cannot reflectively invoke MethodHandle"));
1020 if (!method.getInvocationType().equals(mh.type()))
1021 throw new InternalError(method.toString());
1022 mh = mh.withInternalMemberName(method, false);
1023 mh = mh.asVarargsCollector(Object[].class);
1024 assert(method.isVarargs());
1025 FAKE_METHOD_HANDLE_INVOKE[idx] = mh;
1026 return mh;
1027 }
1028
1029 /**
1030 * Create an alias for the method handle which, when called,
1031 * appears to be called from the same class loader and protection domain
1032 * as hostClass.
1033 * This is an expensive no-op unless the method which is called
1034 * is sensitive to its caller. A small number of system methods
1035 * are in this category, including Class.forName and Method.invoke.
1036 */
1037 static
1038 MethodHandle bindCaller(MethodHandle mh, Class<?> hostClass) {
1039 return BindCaller.bindCaller(mh, hostClass);
1040 }
1041
1042 // Put the whole mess into its own nested class.
1043 // That way we can lazily load the code and set up the constants.
1044 private static class BindCaller {
1045 static
1046 MethodHandle bindCaller(MethodHandle mh, Class<?> hostClass) {
1047 // Do not use this function to inject calls into system classes.
1048 if (hostClass == null
1049 || (hostClass.isArray() ||
1050 hostClass.isPrimitive() ||
1051 hostClass.getName().startsWith("java.") ||
1052 hostClass.getName().startsWith("sun."))) {
1053 throw new InternalError(); // does not happen, and should not anyway
1054 }
1055 // For simplicity, convert mh to a varargs-like method.
1056 MethodHandle vamh = prepareForInvoker(mh);
1057 // Cache the result of makeInjectedInvoker once per argument class.
1058 MethodHandle bccInvoker = CV_makeInjectedInvoker.get(hostClass);
1059 return restoreToType(bccInvoker.bindTo(vamh), mh, hostClass);
1060 }
1061
1062 private static MethodHandle makeInjectedInvoker(Class<?> hostClass) {
1063 Class<?> bcc = UNSAFE.defineAnonymousClass(hostClass, T_BYTES, null);
1064 if (hostClass.getClassLoader() != bcc.getClassLoader())
1065 throw new InternalError(hostClass.getName()+" (CL)");
1066 try {
1067 if (hostClass.getProtectionDomain() != bcc.getProtectionDomain())
1068 throw new InternalError(hostClass.getName()+" (PD)");
1069 } catch (SecurityException ex) {
1070 // Self-check was blocked by security manager. This is OK.
1071 // In fact the whole try body could be turned into an assertion.
1072 }
1073 try {
1074 MethodHandle init = IMPL_LOOKUP.findStatic(bcc, "init", MethodType.methodType(void.class));
1075 init.invokeExact(); // force initialization of the class
1076 } catch (Throwable ex) {
1077 throw uncaughtException(ex);
1078 }
1079 MethodHandle bccInvoker;
1080 try {
1081 MethodType invokerMT = MethodType.methodType(Object.class, MethodHandle.class, Object[].class);
1082 bccInvoker = IMPL_LOOKUP.findStatic(bcc, "invoke_V", invokerMT);
1083 } catch (ReflectiveOperationException ex) {
1084 throw uncaughtException(ex);
1085 }
1086 // Test the invoker, to ensure that it really injects into the right place.
1087 try {
1088 MethodHandle vamh = prepareForInvoker(MH_checkCallerClass);
1089 Object ok = bccInvoker.invokeExact(vamh, new Object[]{hostClass, bcc});
1090 } catch (Throwable ex) {
1091 throw new InternalError(ex);
1092 }
1093 return bccInvoker;
1094 }
1095 private static ClassValue<MethodHandle> CV_makeInjectedInvoker = new ClassValue<MethodHandle>() {
1096 @Override protected MethodHandle computeValue(Class<?> hostClass) {
1097 return makeInjectedInvoker(hostClass);
1098 }
1099 };
1100
1101 // Adapt mh so that it can be called directly from an injected invoker:
1102 private static MethodHandle prepareForInvoker(MethodHandle mh) {
1103 mh = mh.asFixedArity();
1104 MethodType mt = mh.type();
1105 int arity = mt.parameterCount();
1106 MethodHandle vamh = mh.asType(mt.generic());
1107 vamh.internalForm().compileToBytecode(); // eliminate LFI stack frames
1108 vamh = vamh.asSpreader(Object[].class, arity);
1109 vamh.internalForm().compileToBytecode(); // eliminate LFI stack frames
1110 return vamh;
1111 }
1112
1113 // Undo the adapter effect of prepareForInvoker:
1114 private static MethodHandle restoreToType(MethodHandle vamh,
1115 MethodHandle original,
1116 Class<?> hostClass) {
1117 MethodType type = original.type();
1118 MethodHandle mh = vamh.asCollector(Object[].class, type.parameterCount());
1119 MemberName member = original.internalMemberName();
1120 mh = mh.asType(type);
1121 mh = new WrappedMember(mh, type, member, original.isInvokeSpecial(), hostClass);
1122 return mh;
1123 }
1124
1125 private static final MethodHandle MH_checkCallerClass;
1126 static {
1127 final Class<?> THIS_CLASS = BindCaller.class;
1128 assert(checkCallerClass(THIS_CLASS, THIS_CLASS));
1129 try {
1130 MH_checkCallerClass = IMPL_LOOKUP
1131 .findStatic(THIS_CLASS, "checkCallerClass",
1132 MethodType.methodType(boolean.class, Class.class, Class.class));
1133 assert((boolean) MH_checkCallerClass.invokeExact(THIS_CLASS, THIS_CLASS));
1134 } catch (Throwable ex) {
1135 throw new InternalError(ex);
1136 }
1137 }
1138
1139 @CallerSensitive
1140 private static boolean checkCallerClass(Class<?> expected, Class<?> expected2) {
1141 // This method is called via MH_checkCallerClass and so it's
1142 // correct to ask for the immediate caller here.
1143 Class<?> actual = Reflection.getCallerClass();
1144 if (actual != expected && actual != expected2)
1145 throw new InternalError("found "+actual.getName()+", expected "+expected.getName()
1146 +(expected == expected2 ? "" : ", or else "+expected2.getName()));
1147 return true;
1148 }
1149
1150 private static final byte[] T_BYTES;
1151 static {
1152 final Object[] values = {null};
1153 AccessController.doPrivileged(new PrivilegedAction<Void>() {
1154 public Void run() {
1155 try {
1156 Class<T> tClass = T.class;
1157 String tName = tClass.getName();
1158 String tResource = tName.substring(tName.lastIndexOf('.')+1)+".class";
1159 java.net.URLConnection uconn = tClass.getResource(tResource).openConnection();
1160 int len = uconn.getContentLength();
1161 byte[] bytes = new byte[len];
1162 try (java.io.InputStream str = uconn.getInputStream()) {
1163 int nr = str.read(bytes);
1164 if (nr != len) throw new java.io.IOException(tResource);
1165 }
1166 values[0] = bytes;
1167 } catch (java.io.IOException ex) {
1168 throw new InternalError(ex);
1169 }
1170 return null;
1171 }
1172 });
1173 T_BYTES = (byte[]) values[0];
1174 }
1175
1176 // The following class is used as a template for Unsafe.defineAnonymousClass:
1177 private static class T {
1178 static void init() { } // side effect: initializes this class
1179 static Object invoke_V(MethodHandle vamh, Object[] args) throws Throwable {
1180 return vamh.invokeExact(args);
1181 }
1182 }
1183 }
1184
1185
1186 /** This subclass allows a wrapped method handle to be re-associated with an arbitrary member name. */
1187 private static final class WrappedMember extends DelegatingMethodHandle {
1188 private final MethodHandle target;
1189 private final MemberName member;
1190 private final Class<?> callerClass;
1191 private final boolean isInvokeSpecial;
1192
1193 private WrappedMember(MethodHandle target, MethodType type,
1194 MemberName member, boolean isInvokeSpecial,
1195 Class<?> callerClass) {
1196 super(type, target);
1197 this.target = target;
1198 this.member = member;
1199 this.callerClass = callerClass;
1200 this.isInvokeSpecial = isInvokeSpecial;
1201 }
1202
1203 @Override
1204 MemberName internalMemberName() {
1205 return member;
1206 }
1207 @Override
1208 Class<?> internalCallerClass() {
1209 return callerClass;
1210 }
1211 @Override
1212 boolean isInvokeSpecial() {
1213 return isInvokeSpecial;
1214 }
1215 @Override
1216 protected MethodHandle getTarget() {
1217 return target;
1218 }
1219 @Override
1220 public MethodHandle asTypeUncached(MethodType newType) {
1221 // This MH is an alias for target, except for the MemberName
1222 // Drop the MemberName if there is any conversion.
1223 return asTypeCache = target.asType(newType);
1224 }
1225 }
1226
1227 static MethodHandle makeWrappedMember(MethodHandle target, MemberName member, boolean isInvokeSpecial) {
1228 if (member.equals(target.internalMemberName()) && isInvokeSpecial == target.isInvokeSpecial())
1229 return target;
1230 return new WrappedMember(target, target.type(), member, isInvokeSpecial, null);
1231 }
1232
1233 /** Intrinsic IDs */
1234 /*non-public*/
1235 enum Intrinsic {
1236 SELECT_ALTERNATIVE,
1237 GUARD_WITH_CATCH,
1238 NEW_ARRAY,
1239 ARRAY_LOAD,
1240 ARRAY_STORE,
1241 IDENTITY,
1242 ZERO,
1243 NONE // no intrinsic associated
1244 }
1245
1246 /** Mark arbitrary method handle as intrinsic.
1247 * InvokerBytecodeGenerator uses this info to produce more efficient bytecode shape. */
1248 private static final class IntrinsicMethodHandle extends DelegatingMethodHandle {
1249 private final MethodHandle target;
1250 private final Intrinsic intrinsicName;
1251
1252 IntrinsicMethodHandle(MethodHandle target, Intrinsic intrinsicName) {
1253 super(target.type(), target);
1254 this.target = target;
1255 this.intrinsicName = intrinsicName;
1256 }
1257
1258 @Override
1259 protected MethodHandle getTarget() {
1260 return target;
1261 }
1262
1263 @Override
1264 Intrinsic intrinsicName() {
1265 return intrinsicName;
1266 }
1267
1268 @Override
1269 public MethodHandle asTypeUncached(MethodType newType) {
1270 // This MH is an alias for target, except for the intrinsic name
1271 // Drop the name if there is any conversion.
1272 return asTypeCache = target.asType(newType);
1273 }
1274
1275 @Override
1276 String internalProperties() {
1277 return super.internalProperties() +
1278 "\n& Intrinsic="+intrinsicName;
1279 }
1280
1281 @Override
1282 public MethodHandle asCollector(Class<?> arrayType, int arrayLength) {
1283 if (intrinsicName == Intrinsic.IDENTITY) {
1284 MethodType resultType = type().asCollectorType(arrayType, arrayLength);
1285 MethodHandle newArray = MethodHandleImpl.varargsArray(arrayType, arrayLength);
1286 return newArray.asType(resultType);
1287 }
1288 return super.asCollector(arrayType, arrayLength);
1289 }
1290 }
1291
1292 static MethodHandle makeIntrinsic(MethodHandle target, Intrinsic intrinsicName) {
1293 if (intrinsicName == target.intrinsicName())
1294 return target;
1295 return new IntrinsicMethodHandle(target, intrinsicName);
1296 }
1297
1298 static MethodHandle makeIntrinsic(MethodType type, LambdaForm form, Intrinsic intrinsicName) {
1299 return new IntrinsicMethodHandle(SimpleMethodHandle.make(type, form), intrinsicName);
1300 }
1301
1302 /// Collection of multiple arguments.
1303
1304 private static MethodHandle findCollector(String name, int nargs, Class<?> rtype, Class<?>... ptypes) {
1305 MethodType type = MethodType.genericMethodType(nargs)
1306 .changeReturnType(rtype)
1307 .insertParameterTypes(0, ptypes);
1308 try {
1309 return IMPL_LOOKUP.findStatic(MethodHandleImpl.class, name, type);
1310 } catch (ReflectiveOperationException ex) {
1311 return null;
1312 }
1313 }
1314
1315 private static final Object[] NO_ARGS_ARRAY = {};
1316 private static Object[] makeArray(Object... args) { return args; }
1317 private static Object[] array() { return NO_ARGS_ARRAY; }
1318 private static Object[] array(Object a0)
1319 { return makeArray(a0); }
1320 private static Object[] array(Object a0, Object a1)
1321 { return makeArray(a0, a1); }
1322 private static Object[] array(Object a0, Object a1, Object a2)
1323 { return makeArray(a0, a1, a2); }
1324 private static Object[] array(Object a0, Object a1, Object a2, Object a3)
1325 { return makeArray(a0, a1, a2, a3); }
1326 private static Object[] array(Object a0, Object a1, Object a2, Object a3,
1327 Object a4)
1328 { return makeArray(a0, a1, a2, a3, a4); }
1329 private static Object[] array(Object a0, Object a1, Object a2, Object a3,
1330 Object a4, Object a5)
1331 { return makeArray(a0, a1, a2, a3, a4, a5); }
1332 private static Object[] array(Object a0, Object a1, Object a2, Object a3,
1333 Object a4, Object a5, Object a6)
1334 { return makeArray(a0, a1, a2, a3, a4, a5, a6); }
1335 private static Object[] array(Object a0, Object a1, Object a2, Object a3,
1336 Object a4, Object a5, Object a6, Object a7)
1337 { return makeArray(a0, a1, a2, a3, a4, a5, a6, a7); }
1338 private static Object[] array(Object a0, Object a1, Object a2, Object a3,
1339 Object a4, Object a5, Object a6, Object a7,
1340 Object a8)
1341 { return makeArray(a0, a1, a2, a3, a4, a5, a6, a7, a8); }
1342 private static Object[] array(Object a0, Object a1, Object a2, Object a3,
1343 Object a4, Object a5, Object a6, Object a7,
1344 Object a8, Object a9)
1345 { return makeArray(a0, a1, a2, a3, a4, a5, a6, a7, a8, a9); }
1346 private static MethodHandle[] makeArrays() {
1347 ArrayList<MethodHandle> mhs = new ArrayList<>();
1348 for (;;) {
1349 MethodHandle mh = findCollector("array", mhs.size(), Object[].class);
1350 if (mh == null) break;
1351 mh = makeIntrinsic(mh, Intrinsic.NEW_ARRAY);
1352 mhs.add(mh);
1353 }
1354 assert(mhs.size() == 11); // current number of methods
1355 return mhs.toArray(new MethodHandle[MAX_ARITY+1]);
1356 }
1357 private static final MethodHandle[] ARRAYS = makeArrays();
1358
1359 // filling versions of the above:
1360 // using Integer len instead of int len and no varargs to avoid bootstrapping problems
1361 private static Object[] fillNewArray(Integer len, Object[] /*not ...*/ args) {
1362 Object[] a = new Object[len];
1363 fillWithArguments(a, 0, args);
1364 return a;
1365 }
1366 private static Object[] fillNewTypedArray(Object[] example, Integer len, Object[] /*not ...*/ args) {
1367 Object[] a = Arrays.copyOf(example, len);
1368 assert(a.getClass() != Object[].class);
1369 fillWithArguments(a, 0, args);
1370 return a;
1371 }
1372 private static void fillWithArguments(Object[] a, int pos, Object... args) {
1373 System.arraycopy(args, 0, a, pos, args.length);
1374 }
1375 // using Integer pos instead of int pos to avoid bootstrapping problems
1376 private static Object[] fillArray(Integer pos, Object[] a, Object a0)
1377 { fillWithArguments(a, pos, a0); return a; }
1378 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1)
1379 { fillWithArguments(a, pos, a0, a1); return a; }
1380 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2)
1381 { fillWithArguments(a, pos, a0, a1, a2); return a; }
1382 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3)
1383 { fillWithArguments(a, pos, a0, a1, a2, a3); return a; }
1384 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3,
1385 Object a4)
1386 { fillWithArguments(a, pos, a0, a1, a2, a3, a4); return a; }
1387 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3,
1388 Object a4, Object a5)
1389 { fillWithArguments(a, pos, a0, a1, a2, a3, a4, a5); return a; }
1390 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3,
1391 Object a4, Object a5, Object a6)
1392 { fillWithArguments(a, pos, a0, a1, a2, a3, a4, a5, a6); return a; }
1393 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3,
1394 Object a4, Object a5, Object a6, Object a7)
1395 { fillWithArguments(a, pos, a0, a1, a2, a3, a4, a5, a6, a7); return a; }
1396 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3,
1397 Object a4, Object a5, Object a6, Object a7,
1398 Object a8)
1399 { fillWithArguments(a, pos, a0, a1, a2, a3, a4, a5, a6, a7, a8); return a; }
1400 private static Object[] fillArray(Integer pos, Object[] a, Object a0, Object a1, Object a2, Object a3,
1401 Object a4, Object a5, Object a6, Object a7,
1402 Object a8, Object a9)
1403 { fillWithArguments(a, pos, a0, a1, a2, a3, a4, a5, a6, a7, a8, a9); return a; }
1404 private static MethodHandle[] makeFillArrays() {
1405 ArrayList<MethodHandle> mhs = new ArrayList<>();
1406 mhs.add(null); // there is no empty fill; at least a0 is required
1407 for (;;) {
1408 MethodHandle mh = findCollector("fillArray", mhs.size(), Object[].class, Integer.class, Object[].class);
1409 if (mh == null) break;
1410 mhs.add(mh);
1411 }
1412 assert(mhs.size() == 11); // current number of methods
1413 return mhs.toArray(new MethodHandle[0]);
1414 }
1415 private static final MethodHandle[] FILL_ARRAYS = makeFillArrays();
1416
1417 private static Object copyAsPrimitiveArray(Wrapper w, Object... boxes) {
1418 Object a = w.makeArray(boxes.length);
1419 w.copyArrayUnboxing(boxes, 0, a, 0, boxes.length);
1420 return a;
1421 }
1422
1423 /** Return a method handle that takes the indicated number of Object
1424 * arguments and returns an Object array of them, as if for varargs.
1425 */
1426 static MethodHandle varargsArray(int nargs) {
1427 MethodHandle mh = ARRAYS[nargs];
1428 if (mh != null) return mh;
1429 mh = findCollector("array", nargs, Object[].class);
1430 if (mh != null) mh = makeIntrinsic(mh, Intrinsic.NEW_ARRAY);
1431 if (mh != null) return ARRAYS[nargs] = mh;
1432 mh = buildVarargsArray(Lazy.MH_fillNewArray, Lazy.MH_arrayIdentity, nargs);
1433 assert(assertCorrectArity(mh, nargs));
1434 mh = makeIntrinsic(mh, Intrinsic.NEW_ARRAY);
1435 return ARRAYS[nargs] = mh;
1436 }
1437
1438 private static boolean assertCorrectArity(MethodHandle mh, int arity) {
1439 assert(mh.type().parameterCount() == arity) : "arity != "+arity+": "+mh;
1440 return true;
1441 }
1442
1443 // Array identity function (used as Lazy.MH_arrayIdentity).
1444 static <T> T[] identity(T[] x) {
1445 return x;
1446 }
1447
1448 private static MethodHandle buildVarargsArray(MethodHandle newArray, MethodHandle finisher, int nargs) {
1449 // Build up the result mh as a sequence of fills like this:
1450 // finisher(fill(fill(newArrayWA(23,x1..x10),10,x11..x20),20,x21..x23))
1451 // The various fill(_,10*I,___*[J]) are reusable.
1452 int leftLen = Math.min(nargs, LEFT_ARGS); // absorb some arguments immediately
1453 int rightLen = nargs - leftLen;
1454 MethodHandle leftCollector = newArray.bindTo(nargs);
1455 leftCollector = leftCollector.asCollector(Object[].class, leftLen);
1456 MethodHandle mh = finisher;
1457 if (rightLen > 0) {
1458 MethodHandle rightFiller = fillToRight(LEFT_ARGS + rightLen);
1459 if (mh == Lazy.MH_arrayIdentity)
1460 mh = rightFiller;
1461 else
1462 mh = MethodHandles.collectArguments(mh, 0, rightFiller);
1463 }
1464 if (mh == Lazy.MH_arrayIdentity)
1465 mh = leftCollector;
1466 else
1467 mh = MethodHandles.collectArguments(mh, 0, leftCollector);
1468 return mh;
1469 }
1470
1471 private static final int LEFT_ARGS = (FILL_ARRAYS.length - 1);
1472 private static final MethodHandle[] FILL_ARRAY_TO_RIGHT = new MethodHandle[MAX_ARITY+1];
1473 /** fill_array_to_right(N).invoke(a, argL..arg[N-1])
1474 * fills a[L]..a[N-1] with corresponding arguments,
1475 * and then returns a. The value L is a global constant (LEFT_ARGS).
1476 */
1477 private static MethodHandle fillToRight(int nargs) {
1478 MethodHandle filler = FILL_ARRAY_TO_RIGHT[nargs];
1479 if (filler != null) return filler;
1480 filler = buildFiller(nargs);
1481 assert(assertCorrectArity(filler, nargs - LEFT_ARGS + 1));
1482 return FILL_ARRAY_TO_RIGHT[nargs] = filler;
1483 }
1484 private static MethodHandle buildFiller(int nargs) {
1485 if (nargs <= LEFT_ARGS)
1486 return Lazy.MH_arrayIdentity; // no args to fill; return the array unchanged
1487 // we need room for both mh and a in mh.invoke(a, arg*[nargs])
1488 final int CHUNK = LEFT_ARGS;
1489 int rightLen = nargs % CHUNK;
1490 int midLen = nargs - rightLen;
1491 if (rightLen == 0) {
1492 midLen = nargs - (rightLen = CHUNK);
1493 if (FILL_ARRAY_TO_RIGHT[midLen] == null) {
1494 // build some precursors from left to right
1495 for (int j = LEFT_ARGS % CHUNK; j < midLen; j += CHUNK)
1496 if (j > LEFT_ARGS) fillToRight(j);
1497 }
1498 }
1499 if (midLen < LEFT_ARGS) rightLen = nargs - (midLen = LEFT_ARGS);
1500 assert(rightLen > 0);
1501 MethodHandle midFill = fillToRight(midLen); // recursive fill
1502 MethodHandle rightFill = FILL_ARRAYS[rightLen].bindTo(midLen); // [midLen..nargs-1]
1503 assert(midFill.type().parameterCount() == 1 + midLen - LEFT_ARGS);
1504 assert(rightFill.type().parameterCount() == 1 + rightLen);
1505
1506 // Combine the two fills:
1507 // right(mid(a, x10..x19), x20..x23)
1508 // The final product will look like this:
1509 // right(mid(newArrayLeft(24, x0..x9), x10..x19), x20..x23)
1510 if (midLen == LEFT_ARGS)
1511 return rightFill;
1512 else
1513 return MethodHandles.collectArguments(rightFill, 0, midFill);
1514 }
1515
1516 // Type-polymorphic version of varargs maker.
1517 private static final ClassValue<MethodHandle[]> TYPED_COLLECTORS
1518 = new ClassValue<MethodHandle[]>() {
1519 @Override
1520 protected MethodHandle[] computeValue(Class<?> type) {
1521 return new MethodHandle[256];
1522 }
1523 };
1524
1525 static final int MAX_JVM_ARITY = 255; // limit imposed by the JVM
1526
1527 /** Return a method handle that takes the indicated number of
1528 * typed arguments and returns an array of them.
1529 * The type argument is the array type.
1530 */
1531 static MethodHandle varargsArray(Class<?> arrayType, int nargs) {
1532 Class<?> elemType = arrayType.getComponentType();
1533 if (elemType == null) throw new IllegalArgumentException("not an array: "+arrayType);
1534 // FIXME: Need more special casing and caching here.
1535 if (nargs >= MAX_JVM_ARITY/2 - 1) {
1536 int slots = nargs;
1537 final int MAX_ARRAY_SLOTS = MAX_JVM_ARITY - 1; // 1 for receiver MH
1538 if (slots <= MAX_ARRAY_SLOTS && elemType.isPrimitive())
1539 slots *= Wrapper.forPrimitiveType(elemType).stackSlots();
1540 if (slots > MAX_ARRAY_SLOTS)
1541 throw new IllegalArgumentException("too many arguments: "+arrayType.getSimpleName()+", length "+nargs);
1542 }
1543 if (elemType == Object.class)
1544 return varargsArray(nargs);
1545 // other cases: primitive arrays, subtypes of Object[]
1546 MethodHandle cache[] = TYPED_COLLECTORS.get(elemType);
1547 MethodHandle mh = nargs < cache.length ? cache[nargs] : null;
1548 if (mh != null) return mh;
1549 if (nargs == 0) {
1550 Object example = java.lang.reflect.Array.newInstance(arrayType.getComponentType(), 0);
1551 mh = MethodHandles.constant(arrayType, example);
1552 } else if (elemType.isPrimitive()) {
1553 MethodHandle builder = Lazy.MH_fillNewArray;
1554 MethodHandle producer = buildArrayProducer(arrayType);
1555 mh = buildVarargsArray(builder, producer, nargs);
1556 } else {
1557 Class<? extends Object[]> objArrayType = arrayType.asSubclass(Object[].class);
1558 Object[] example = Arrays.copyOf(NO_ARGS_ARRAY, 0, objArrayType);
1559 MethodHandle builder = Lazy.MH_fillNewTypedArray.bindTo(example);
1560 MethodHandle producer = Lazy.MH_arrayIdentity; // must be weakly typed
1561 mh = buildVarargsArray(builder, producer, nargs);
1562 }
1563 mh = mh.asType(MethodType.methodType(arrayType, Collections.<Class<?>>nCopies(nargs, elemType)));
1564 mh = makeIntrinsic(mh, Intrinsic.NEW_ARRAY);
1565 assert(assertCorrectArity(mh, nargs));
1566 if (nargs < cache.length)
1567 cache[nargs] = mh;
1568 return mh;
1569 }
1570
1571 private static MethodHandle buildArrayProducer(Class<?> arrayType) {
1572 Class<?> elemType = arrayType.getComponentType();
1573 assert(elemType.isPrimitive());
1574 return Lazy.MH_copyAsPrimitiveArray.bindTo(Wrapper.forPrimitiveType(elemType));
1575 }
1576 }