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