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.Arrays;
31 import java.util.HashMap;
32 import sun.invoke.empty.Empty;
33 import sun.invoke.util.ValueConversions;
34 import sun.invoke.util.VerifyType;
35 import sun.invoke.util.Wrapper;
36 import sun.reflect.CallerSensitive;
37 import sun.reflect.Reflection;
38 import static java.lang.invoke.LambdaForm.*;
39 import static java.lang.invoke.MethodHandleStatics.*;
40 import static java.lang.invoke.MethodHandles.Lookup.IMPL_LOOKUP;
41
42 /**
43 * Trusted implementation code for MethodHandle.
44 * @author jrose
45 */
46 /*non-public*/ abstract class MethodHandleImpl {
47 /// Factory methods to create method handles:
48
49 static void initStatics() {
50 // Trigger selected static initializations.
51 MemberName.Factory.INSTANCE.getClass();
52 }
53
54 static MethodHandle makeArrayElementAccessor(Class<?> arrayClass, boolean isSetter) {
55 if (!arrayClass.isArray())
56 throw newIllegalArgumentException("not an array: "+arrayClass);
57 MethodHandle accessor = ArrayAccessor.getAccessor(arrayClass, isSetter);
58 MethodType srcType = accessor.type().erase();
59 MethodType lambdaType = srcType.invokerType();
60 Name[] names = arguments(1, lambdaType);
61 Name[] args = Arrays.copyOfRange(names, 1, 1 + srcType.parameterCount());
62 names[names.length - 1] = new Name(accessor.asType(srcType), (Object[]) args);
63 LambdaForm form = new LambdaForm("getElement", lambdaType.parameterCount(), names);
64 MethodHandle mh = SimpleMethodHandle.make(srcType, form);
65 if (ArrayAccessor.needCast(arrayClass)) {
66 mh = mh.bindTo(arrayClass);
67 }
68 mh = mh.asType(ArrayAccessor.correctType(arrayClass, isSetter));
69 return mh;
70 }
71
72 static final class ArrayAccessor {
73 /// Support for array element access
74 static final HashMap<Class<?>, MethodHandle> GETTER_CACHE = new HashMap<>(); // TODO use it
75 static final HashMap<Class<?>, MethodHandle> SETTER_CACHE = new HashMap<>(); // TODO use it
76
77 static int getElementI(int[] a, int i) { return a[i]; }
78 static long getElementJ(long[] a, int i) { return a[i]; }
79 static float getElementF(float[] a, int i) { return a[i]; }
80 static double getElementD(double[] a, int i) { return a[i]; }
81 static boolean getElementZ(boolean[] a, int i) { return a[i]; }
82 static byte getElementB(byte[] a, int i) { return a[i]; }
83 static short getElementS(short[] a, int i) { return a[i]; }
84 static char getElementC(char[] a, int i) { return a[i]; }
85 static Object getElementL(Object[] a, int i) { return a[i]; }
86
87 static void setElementI(int[] a, int i, int x) { a[i] = x; }
88 static void setElementJ(long[] a, int i, long x) { a[i] = x; }
89 static void setElementF(float[] a, int i, float x) { a[i] = x; }
90 static void setElementD(double[] a, int i, double x) { a[i] = x; }
91 static void setElementZ(boolean[] a, int i, boolean x) { a[i] = x; }
92 static void setElementB(byte[] a, int i, byte x) { a[i] = x; }
93 static void setElementS(short[] a, int i, short x) { a[i] = x; }
94 static void setElementC(char[] a, int i, char x) { a[i] = x; }
95 static void setElementL(Object[] a, int i, Object x) { a[i] = x; }
96
97 static Object getElementL(Class<?> arrayClass, Object[] a, int i) { arrayClass.cast(a); return a[i]; }
98 static void setElementL(Class<?> arrayClass, Object[] a, int i, Object x) { arrayClass.cast(a); a[i] = x; }
99
100 // Weakly typed wrappers of Object[] accessors:
101 static Object getElementL(Object a, int i) { return getElementL((Object[])a, i); }
102 static void setElementL(Object a, int i, Object x) { setElementL((Object[]) a, i, x); }
103 static Object getElementL(Object arrayClass, Object a, int i) { return getElementL((Class<?>) arrayClass, (Object[])a, i); }
104 static void setElementL(Object arrayClass, Object a, int i, Object x) { setElementL((Class<?>) arrayClass, (Object[])a, i, x); }
105
106 static boolean needCast(Class<?> arrayClass) {
107 Class<?> elemClass = arrayClass.getComponentType();
108 return !elemClass.isPrimitive() && elemClass != Object.class;
109 }
110 static String name(Class<?> arrayClass, boolean isSetter) {
111 Class<?> elemClass = arrayClass.getComponentType();
112 if (elemClass == null) throw new IllegalArgumentException();
113 return (!isSetter ? "getElement" : "setElement") + Wrapper.basicTypeChar(elemClass);
114 }
115 static final boolean USE_WEAKLY_TYPED_ARRAY_ACCESSORS = false; // FIXME: decide
116 static MethodType type(Class<?> arrayClass, boolean isSetter) {
117 Class<?> elemClass = arrayClass.getComponentType();
118 Class<?> arrayArgClass = arrayClass;
119 if (!elemClass.isPrimitive()) {
120 arrayArgClass = Object[].class;
121 if (USE_WEAKLY_TYPED_ARRAY_ACCESSORS)
122 arrayArgClass = Object.class;
123 }
124 if (!needCast(arrayClass)) {
125 return !isSetter ?
126 MethodType.methodType(elemClass, arrayArgClass, int.class) :
127 MethodType.methodType(void.class, arrayArgClass, int.class, elemClass);
128 } else {
129 Class<?> classArgClass = Class.class;
130 if (USE_WEAKLY_TYPED_ARRAY_ACCESSORS)
131 classArgClass = Object.class;
132 return !isSetter ?
133 MethodType.methodType(Object.class, classArgClass, arrayArgClass, int.class) :
134 MethodType.methodType(void.class, classArgClass, arrayArgClass, int.class, Object.class);
135 }
136 }
137 static MethodType correctType(Class<?> arrayClass, boolean isSetter) {
138 Class<?> elemClass = arrayClass.getComponentType();
139 return !isSetter ?
140 MethodType.methodType(elemClass, arrayClass, int.class) :
141 MethodType.methodType(void.class, arrayClass, int.class, elemClass);
142 }
143 static MethodHandle getAccessor(Class<?> arrayClass, boolean isSetter) {
144 String name = name(arrayClass, isSetter);
145 MethodType type = type(arrayClass, isSetter);
146 try {
147 return IMPL_LOOKUP.findStatic(ArrayAccessor.class, name, type);
148 } catch (ReflectiveOperationException ex) {
149 throw uncaughtException(ex);
150 }
151 }
152 }
153
154 /**
155 * Create a JVM-level adapter method handle to conform the given method
156 * handle to the similar newType, using only pairwise argument conversions.
157 * For each argument, convert incoming argument to the exact type needed.
158 * The argument conversions allowed are casting, boxing and unboxing,
159 * integral widening or narrowing, and floating point widening or narrowing.
160 * @param srcType required call type
161 * @param target original method handle
162 * @param level which strength of conversion is allowed
163 * @return an adapter to the original handle with the desired new type,
164 * or the original target if the types are already identical
165 * or null if the adaptation cannot be made
166 */
167 static MethodHandle makePairwiseConvert(MethodHandle target, MethodType srcType, int level) {
168 assert(level >= 0 && level <= 2);
169 MethodType dstType = target.type();
170 assert(dstType.parameterCount() == target.type().parameterCount());
171 if (srcType == dstType)
172 return target;
173
174 // Calculate extra arguments (temporaries) required in the names array.
175 // FIXME: Use an ArrayList<Name>. Some arguments require more than one conversion step.
176 final int INARG_COUNT = srcType.parameterCount();
177 int conversions = 0;
178 boolean[] needConv = new boolean[1+INARG_COUNT];
179 for (int i = 0; i <= INARG_COUNT; i++) {
180 Class<?> src = (i == INARG_COUNT) ? dstType.returnType() : srcType.parameterType(i);
181 Class<?> dst = (i == INARG_COUNT) ? srcType.returnType() : dstType.parameterType(i);
182 if (!VerifyType.isNullConversion(src, dst) ||
183 level <= 1 && dst.isInterface() && !dst.isAssignableFrom(src)) {
184 needConv[i] = true;
185 conversions++;
186 }
187 }
188 boolean retConv = needConv[INARG_COUNT];
189
190 final int IN_MH = 0;
191 final int INARG_BASE = 1;
192 final int INARG_LIMIT = INARG_BASE + INARG_COUNT;
193 final int NAME_LIMIT = INARG_LIMIT + conversions + 1;
194 final int RETURN_CONV = (!retConv ? -1 : NAME_LIMIT - 1);
195 final int OUT_CALL = (!retConv ? NAME_LIMIT : RETURN_CONV) - 1;
196
197 // Now build a LambdaForm.
198 MethodType lambdaType = srcType.basicType().invokerType();
199 Name[] names = arguments(NAME_LIMIT - INARG_LIMIT, lambdaType);
200
201 // Collect the arguments to the outgoing call, maybe with conversions:
202 final int OUTARG_BASE = 0; // target MH is Name.function, name Name.arguments[0]
203 Object[] outArgs = new Object[OUTARG_BASE + INARG_COUNT];
204
205 int nameCursor = INARG_LIMIT;
206 for (int i = 0; i < INARG_COUNT; i++) {
207 Class<?> src = srcType.parameterType(i);
208 Class<?> dst = dstType.parameterType(i);
209
210 if (!needConv[i]) {
211 // do nothing: difference is trivial
212 outArgs[OUTARG_BASE + i] = names[INARG_BASE + i];
213 continue;
214 }
215
216 // Tricky case analysis follows.
217 MethodHandle fn = null;
218 if (src.isPrimitive()) {
219 if (dst.isPrimitive()) {
220 fn = ValueConversions.convertPrimitive(src, dst);
221 } else {
222 Wrapper w = Wrapper.forPrimitiveType(src);
223 MethodHandle boxMethod = ValueConversions.box(w);
224 if (dst == w.wrapperType())
225 fn = boxMethod;
226 else
227 fn = boxMethod.asType(MethodType.methodType(dst, src));
228 }
229 } else {
230 if (dst.isPrimitive()) {
231 // Caller has boxed a primitive. Unbox it for the target.
232 Wrapper w = Wrapper.forPrimitiveType(dst);
233 if (level == 0 || VerifyType.isNullConversion(src, w.wrapperType())) {
234 fn = ValueConversions.unbox(dst);
235 } else if (src == Object.class || !Wrapper.isWrapperType(src)) {
236 // Examples: Object->int, Number->int, Comparable->int; Byte->int, Character->int
237 // must include additional conversions
238 // src must be examined at runtime, to detect Byte, Character, etc.
239 MethodHandle unboxMethod = (level == 1
240 ? ValueConversions.unbox(dst)
241 : ValueConversions.unboxCast(dst));
242 fn = unboxMethod;
243 } else {
244 // Example: Byte->int
245 // Do this by reformulating the problem to Byte->byte.
246 Class<?> srcPrim = Wrapper.forWrapperType(src).primitiveType();
247 MethodHandle unbox = ValueConversions.unbox(srcPrim);
248 // Compose the two conversions. FIXME: should make two Names for this job
249 fn = unbox.asType(MethodType.methodType(dst, src));
250 }
251 } else {
252 // Simple reference conversion.
253 // Note: Do not check for a class hierarchy relation
254 // between src and dst. In all cases a 'null' argument
255 // will pass the cast conversion.
256 fn = ValueConversions.cast(dst);
257 }
258 }
259 Name conv = new Name(fn, names[INARG_BASE + i]);
260 assert(names[nameCursor] == null);
261 names[nameCursor++] = conv;
262 assert(outArgs[OUTARG_BASE + i] == null);
263 outArgs[OUTARG_BASE + i] = conv;
264 }
265
266 // Build argument array for the call.
267 assert(nameCursor == OUT_CALL);
268 names[OUT_CALL] = new Name(target, outArgs);
269
270 if (RETURN_CONV < 0) {
271 assert(OUT_CALL == names.length-1);
272 } else {
273 Class<?> needReturn = srcType.returnType();
274 Class<?> haveReturn = dstType.returnType();
275 MethodHandle fn;
276 Object[] arg = { names[OUT_CALL] };
277 if (haveReturn == void.class) {
278 // synthesize a zero value for the given void
279 Object zero = Wrapper.forBasicType(needReturn).zero();
280 fn = MethodHandles.constant(needReturn, zero);
281 arg = new Object[0]; // don't pass names[OUT_CALL] to conversion
282 } else {
283 MethodHandle identity = MethodHandles.identity(needReturn);
284 MethodType needConversion = identity.type().changeParameterType(0, haveReturn);
285 fn = makePairwiseConvert(identity, needConversion, level);
286 }
287 assert(names[RETURN_CONV] == null);
288 names[RETURN_CONV] = new Name(fn, arg);
289 assert(RETURN_CONV == names.length-1);
290 }
291
292 LambdaForm form = new LambdaForm("convert", lambdaType.parameterCount(), names);
293 return SimpleMethodHandle.make(srcType, form);
294 }
295
296 static MethodHandle makeReferenceIdentity(Class<?> refType) {
297 MethodType lambdaType = MethodType.genericMethodType(1).invokerType();
298 Name[] names = arguments(1, lambdaType);
299 names[names.length - 1] = new Name(ValueConversions.identity(), names[1]);
300 LambdaForm form = new LambdaForm("identity", lambdaType.parameterCount(), names);
301 return SimpleMethodHandle.make(MethodType.methodType(refType, refType), form);
302 }
303
304 static MethodHandle makeVarargsCollector(MethodHandle target, Class<?> arrayType) {
305 MethodType type = target.type();
306 int last = type.parameterCount() - 1;
307 if (type.parameterType(last) != arrayType)
308 target = target.asType(type.changeParameterType(last, arrayType));
309 target = target.asFixedArity(); // make sure this attribute is turned off
310 return new AsVarargsCollector(target, target.type(), arrayType);
311 }
312
313 static class AsVarargsCollector extends MethodHandle {
314 private final MethodHandle target;
315 private final Class<?> arrayType;
316 private /*@Stable*/ MethodHandle asCollectorCache;
317
318 AsVarargsCollector(MethodHandle target, MethodType type, Class<?> arrayType) {
319 super(type, reinvokerForm(target));
320 this.target = target;
321 this.arrayType = arrayType;
322 this.asCollectorCache = target.asCollector(arrayType, 0);
323 }
324
325 @Override MethodHandle reinvokerTarget() { return target; }
326
327 @Override
328 public boolean isVarargsCollector() {
329 return true;
330 }
331
332 @Override
333 public MethodHandle asFixedArity() {
334 return target;
335 }
336
337 @Override
338 public MethodHandle asTypeUncached(MethodType newType) {
339 MethodType type = this.type();
340 int collectArg = type.parameterCount() - 1;
341 int newArity = newType.parameterCount();
342 if (newArity == collectArg+1 &&
343 type.parameterType(collectArg).isAssignableFrom(newType.parameterType(collectArg))) {
344 // if arity and trailing parameter are compatible, do normal thing
345 return asTypeCache = asFixedArity().asType(newType);
346 }
347 // check cache
348 MethodHandle acc = asCollectorCache;
349 if (acc != null && acc.type().parameterCount() == newArity)
350 return asTypeCache = acc.asType(newType);
351 // build and cache a collector
352 int arrayLength = newArity - collectArg;
353 MethodHandle collector;
354 try {
355 collector = asFixedArity().asCollector(arrayType, arrayLength);
356 assert(collector.type().parameterCount() == newArity) : "newArity="+newArity+" but collector="+collector;
357 } catch (IllegalArgumentException ex) {
358 throw new WrongMethodTypeException("cannot build collector", ex);
359 }
360 asCollectorCache = collector;
361 return asTypeCache = collector.asType(newType);
362 }
363
364 @Override
365 MethodHandle setVarargs(MemberName member) {
366 if (member.isVarargs()) return this;
367 return asFixedArity();
368 }
369
370 @Override
371 MethodHandle viewAsType(MethodType newType) {
372 if (newType.lastParameterType() != type().lastParameterType())
373 throw new InternalError();
374 MethodHandle newTarget = asFixedArity().viewAsType(newType);
375 // put back the varargs bit:
376 return new AsVarargsCollector(newTarget, newType, arrayType);
377 }
378
379 @Override
380 MemberName internalMemberName() {
381 return asFixedArity().internalMemberName();
382 }
383 @Override
384 Class<?> internalCallerClass() {
385 return asFixedArity().internalCallerClass();
386 }
387
388 /*non-public*/
389 @Override
390 boolean isInvokeSpecial() {
391 return asFixedArity().isInvokeSpecial();
392 }
393
394
395 @Override
396 MethodHandle bindArgument(int pos, char basicType, Object value) {
397 return asFixedArity().bindArgument(pos, basicType, value);
398 }
399
400 @Override
401 MethodHandle bindReceiver(Object receiver) {
402 return asFixedArity().bindReceiver(receiver);
403 }
404
405 @Override
406 MethodHandle dropArguments(MethodType srcType, int pos, int drops) {
407 return asFixedArity().dropArguments(srcType, pos, drops);
408 }
409
410 @Override
411 MethodHandle permuteArguments(MethodType newType, int[] reorder) {
412 return asFixedArity().permuteArguments(newType, reorder);
413 }
414 }
415
416 /** Factory method: Spread selected argument. */
417 static MethodHandle makeSpreadArguments(MethodHandle target,
418 Class<?> spreadArgType, int spreadArgPos, int spreadArgCount) {
419 MethodType targetType = target.type();
420
421 for (int i = 0; i < spreadArgCount; i++) {
422 Class<?> arg = VerifyType.spreadArgElementType(spreadArgType, i);
423 if (arg == null) arg = Object.class;
424 targetType = targetType.changeParameterType(spreadArgPos + i, arg);
425 }
426 target = target.asType(targetType);
427
428 MethodType srcType = targetType
429 .replaceParameterTypes(spreadArgPos, spreadArgPos + spreadArgCount, spreadArgType);
430 // Now build a LambdaForm.
431 MethodType lambdaType = srcType.invokerType();
432 Name[] names = arguments(spreadArgCount + 2, lambdaType);
433 int nameCursor = lambdaType.parameterCount();
434 int[] indexes = new int[targetType.parameterCount()];
435
436 for (int i = 0, argIndex = 1; i < targetType.parameterCount() + 1; i++, argIndex++) {
437 Class<?> src = lambdaType.parameterType(i);
438 if (i == spreadArgPos) {
439 // Spread the array.
440 MethodHandle aload = MethodHandles.arrayElementGetter(spreadArgType);
441 Name array = names[argIndex];
442 names[nameCursor++] = new Name(Lazy.NF_checkSpreadArgument, array, spreadArgCount);
443 for (int j = 0; j < spreadArgCount; i++, j++) {
444 indexes[i] = nameCursor;
445 names[nameCursor++] = new Name(aload, array, j);
446 }
447 } else if (i < indexes.length) {
448 indexes[i] = argIndex;
449 }
450 }
451 assert(nameCursor == names.length-1); // leave room for the final call
452
453 // Build argument array for the call.
454 Name[] targetArgs = new Name[targetType.parameterCount()];
455 for (int i = 0; i < targetType.parameterCount(); i++) {
456 int idx = indexes[i];
457 targetArgs[i] = names[idx];
458 }
459 names[names.length - 1] = new Name(target, (Object[]) targetArgs);
460
461 LambdaForm form = new LambdaForm("spread", lambdaType.parameterCount(), names);
462 return SimpleMethodHandle.make(srcType, form);
463 }
464
465 static void checkSpreadArgument(Object av, int n) {
466 if (av == null) {
467 if (n == 0) return;
468 } else if (av instanceof Object[]) {
469 int len = ((Object[])av).length;
470 if (len == n) return;
471 } else {
472 int len = java.lang.reflect.Array.getLength(av);
473 if (len == n) return;
474 }
475 // fall through to error:
476 throw newIllegalArgumentException("array is not of length "+n);
477 }
478
479 /**
480 * Pre-initialized NamedFunctions for bootstrapping purposes.
481 * Factored in an inner class to delay initialization until first usage.
482 */
483 private static class Lazy {
484 static final NamedFunction NF_checkSpreadArgument;
485 static {
486 try {
487 NF_checkSpreadArgument = new NamedFunction(MethodHandleImpl.class
488 .getDeclaredMethod("checkSpreadArgument", Object.class, int.class));
489 NF_checkSpreadArgument.resolve();
490 } catch (ReflectiveOperationException ex) {
491 throw newInternalError(ex);
492 }
493 }
494 }
495
496 /** Factory method: Collect or filter selected argument(s). */
497 static MethodHandle makeCollectArguments(MethodHandle target,
498 MethodHandle collector, int collectArgPos, boolean retainOriginalArgs) {
499 MethodType targetType = target.type(); // (a..., c, [b...])=>r
500 MethodType collectorType = collector.type(); // (b...)=>c
501 int collectArgCount = collectorType.parameterCount();
502 Class<?> collectValType = collectorType.returnType();
503 int collectValCount = (collectValType == void.class ? 0 : 1);
504 MethodType srcType = targetType // (a..., [b...])=>r
505 .dropParameterTypes(collectArgPos, collectArgPos+collectValCount);
506 if (!retainOriginalArgs) { // (a..., b...)=>r
507 srcType = srcType.insertParameterTypes(collectArgPos, collectorType.parameterList());
508 }
509 // in arglist: [0: ...keep1 | cpos: collect... | cpos+cacount: keep2... ]
510 // out arglist: [0: ...keep1 | cpos: collectVal? | cpos+cvcount: keep2... ]
511 // out(retain): [0: ...keep1 | cpos: cV? coll... | cpos+cvc+cac: keep2... ]
512
513 // Now build a LambdaForm.
514 MethodType lambdaType = srcType.invokerType();
515 Name[] names = arguments(2, lambdaType);
516 final int collectNamePos = names.length - 2;
517 final int targetNamePos = names.length - 1;
518
519 Name[] collectorArgs = Arrays.copyOfRange(names, 1 + collectArgPos, 1 + collectArgPos + collectArgCount);
520 names[collectNamePos] = new Name(collector, (Object[]) collectorArgs);
521
522 // Build argument array for the target.
523 // Incoming LF args to copy are: [ (mh) headArgs collectArgs tailArgs ].
524 // Output argument array is [ headArgs (collectVal)? (collectArgs)? tailArgs ].
525 Name[] targetArgs = new Name[targetType.parameterCount()];
526 int inputArgPos = 1; // incoming LF args to copy to target
527 int targetArgPos = 0; // fill pointer for targetArgs
528 int chunk = collectArgPos; // |headArgs|
529 System.arraycopy(names, inputArgPos, targetArgs, targetArgPos, chunk);
530 inputArgPos += chunk;
531 targetArgPos += chunk;
532 if (collectValType != void.class) {
533 targetArgs[targetArgPos++] = names[collectNamePos];
534 }
535 chunk = collectArgCount;
536 if (retainOriginalArgs) {
537 System.arraycopy(names, inputArgPos, targetArgs, targetArgPos, chunk);
538 targetArgPos += chunk; // optionally pass on the collected chunk
539 }
540 inputArgPos += chunk;
541 chunk = targetArgs.length - targetArgPos; // all the rest
542 System.arraycopy(names, inputArgPos, targetArgs, targetArgPos, chunk);
543 assert(inputArgPos + chunk == collectNamePos); // use of rest of input args also
544 names[targetNamePos] = new Name(target, (Object[]) targetArgs);
545
546 LambdaForm form = new LambdaForm("collect", lambdaType.parameterCount(), names);
547 return SimpleMethodHandle.make(srcType, form);
548 }
549
550 @LambdaForm.Hidden
551 static
552 MethodHandle selectAlternative(boolean testResult, MethodHandle target, MethodHandle fallback) {
553 return testResult ? target : fallback;
554 }
555
556 static MethodHandle SELECT_ALTERNATIVE;
557 static MethodHandle selectAlternative() {
558 if (SELECT_ALTERNATIVE != null) return SELECT_ALTERNATIVE;
559 try {
560 SELECT_ALTERNATIVE
561 = IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "selectAlternative",
562 MethodType.methodType(MethodHandle.class, boolean.class, MethodHandle.class, MethodHandle.class));
563 } catch (ReflectiveOperationException ex) {
564 throw uncaughtException(ex);
565 }
566 return SELECT_ALTERNATIVE;
567 }
568
569 static
570 MethodHandle makeGuardWithTest(MethodHandle test,
571 MethodHandle target,
572 MethodHandle fallback) {
573 MethodType basicType = target.type().basicType();
574 MethodHandle invokeBasic = MethodHandles.basicInvoker(basicType);
575 int arity = basicType.parameterCount();
576 int extraNames = 3;
577 MethodType lambdaType = basicType.invokerType();
578 Name[] names = arguments(extraNames, lambdaType);
579
580 Object[] testArgs = Arrays.copyOfRange(names, 1, 1 + arity, Object[].class);
581 Object[] targetArgs = Arrays.copyOfRange(names, 0, 1 + arity, Object[].class);
582
583 // call test
584 names[arity + 1] = new Name(test, testArgs);
585
586 // call selectAlternative
587 Object[] selectArgs = { names[arity + 1], target, fallback };
588 names[arity + 2] = new Name(MethodHandleImpl.selectAlternative(), selectArgs);
589 targetArgs[0] = names[arity + 2];
590
591 // call target or fallback
592 names[arity + 3] = new Name(new NamedFunction(invokeBasic), targetArgs);
593
594 LambdaForm form = new LambdaForm("guard", lambdaType.parameterCount(), names);
595 return SimpleMethodHandle.make(target.type(), form);
596 }
597
598 /**
599 * The LambaForm shape for catchException combinator is the following:
600 * <blockquote><pre>{@code
601 * guardWithCatch=Lambda(a0:L,a1:L,a2:L)=>{
602 * t3:L=BoundMethodHandle$Species_LLLLL.argL0(a0:L);
603 * t4:L=BoundMethodHandle$Species_LLLLL.argL1(a0:L);
604 * t5:L=BoundMethodHandle$Species_LLLLL.argL2(a0:L);
605 * t6:L=BoundMethodHandle$Species_LLLLL.argL3(a0:L);
606 * t7:L=BoundMethodHandle$Species_LLLLL.argL4(a0:L);
607 * t8:L=MethodHandle.invokeBasic(t6:L,a1:L,a2:L);
608 * t9:L=MethodHandleImpl.guardWithCatch(t3:L,t4:L,t5:L,t8:L);
609 * t10:I=MethodHandle.invokeBasic(t7:L,t9:L);t10:I}
610 * }</pre></blockquote>
611 *
612 * argL0 and argL2 are target and catcher method handles. argL1 is exception class.
613 * argL3 and argL4 are auxiliary method handles: argL3 boxes arguments and wraps them into Object[]
614 * (ValueConversions.array()) and argL4 unboxes result if necessary (ValueConversions.unbox()).
615 *
616 * Having t8 and t10 passed outside and not hardcoded into a lambda form allows to share lambda forms
617 * among catchException combinators with the same basic type.
618 */
619 private static LambdaForm makeGuardWithCatchForm(MethodType basicType) {
620 MethodType lambdaType = basicType.invokerType();
621
622 LambdaForm lform = basicType.form().cachedLambdaForm(MethodTypeForm.LF_GWC);
623 if (lform != null) {
624 return lform;
625 }
626
627 final int THIS_MH = 0; // the BMH_LLLLL
628 final int ARG_BASE = 1; // start of incoming arguments
629 final int ARG_LIMIT = ARG_BASE + basicType.parameterCount();
630
631 int nameCursor = ARG_LIMIT;
632 final int GET_TARGET = nameCursor++;
633 final int GET_CLASS = nameCursor++;
634 final int GET_CATCHER = nameCursor++;
635 final int GET_COLLECT_ARGS = nameCursor++;
636 final int GET_UNBOX_RESULT = nameCursor++;
637 final int BOXED_ARGS = nameCursor++;
638 final int TRY_CATCH = nameCursor++;
639 final int UNBOX_RESULT = nameCursor++;
640
641 Name[] names = arguments(nameCursor - ARG_LIMIT, lambdaType);
642
643 BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_LLLLL();
644 names[GET_TARGET] = new Name(data.getterFunction(0), names[THIS_MH]);
645 names[GET_CLASS] = new Name(data.getterFunction(1), names[THIS_MH]);
646 names[GET_CATCHER] = new Name(data.getterFunction(2), names[THIS_MH]);
647 names[GET_COLLECT_ARGS] = new Name(data.getterFunction(3), names[THIS_MH]);
648 names[GET_UNBOX_RESULT] = new Name(data.getterFunction(4), names[THIS_MH]);
649
650 // t_{i}:L=MethodHandle.invokeBasic(collectArgs:L,a1:L,...);
651 MethodType collectArgsType = basicType.changeReturnType(Object.class);
652 MethodHandle invokeBasic = MethodHandles.basicInvoker(collectArgsType);
653 Object[] args = new Object[invokeBasic.type().parameterCount()];
654 args[0] = names[GET_COLLECT_ARGS];
655 System.arraycopy(names, ARG_BASE, args, 1, ARG_LIMIT-ARG_BASE);
656 names[BOXED_ARGS] = new Name(new NamedFunction(invokeBasic), args);
657
658 // t_{i+1}:L=MethodHandleImpl.guardWithCatch(target:L,exType:L,catcher:L,t_{i}:L);
659 Object[] gwcArgs = new Object[] {names[GET_TARGET], names[GET_CLASS], names[GET_CATCHER], names[BOXED_ARGS]};
660 names[TRY_CATCH] = new Name(MethodHandleImpl.guardWithCatch(), gwcArgs);
661
662 // t_{i+2}:I=MethodHandle.invokeBasic(unbox:L,t_{i+1}:L);
663 MethodHandle invokeBasicUnbox = MethodHandles.basicInvoker(MethodType.methodType(basicType.rtype(), Object.class));
664 Object[] unboxArgs = new Object[] {names[GET_UNBOX_RESULT], names[TRY_CATCH]};
665 names[UNBOX_RESULT] = new Name(new NamedFunction(invokeBasicUnbox), unboxArgs);
666
667 lform = new LambdaForm("guardWithCatch", lambdaType.parameterCount(), names);
668
669 basicType.form().setCachedLambdaForm(MethodTypeForm.LF_GWC, lform);
670 return lform;
671 }
672
673 static
674 MethodHandle makeGuardWithCatch(MethodHandle target,
675 Class<? extends Throwable> exType,
676 MethodHandle catcher) {
677 MethodType type = target.type();
678 LambdaForm form = makeGuardWithCatchForm(type.basicType());
679
680 // Prepare auxiliary method handles used during LambdaForm interpreation.
681 // Box arguments and wrap them into Object[]: ValueConversions.array().
682 MethodType varargsType = type.changeReturnType(Object[].class);
683 MethodHandle collectArgs = ValueConversions.varargsArray(type.parameterCount())
684 .asType(varargsType);
685 // Result unboxing: ValueConversions.unbox() OR ValueConversions.identity() OR ValueConversions.ignore().
686 MethodHandle unboxResult;
687 if (type.returnType().isPrimitive()) {
688 unboxResult = ValueConversions.unbox(type.returnType());
689 } else {
690 unboxResult = ValueConversions.identity();
691 }
692
693 BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_LLLLL();
694 BoundMethodHandle mh;
695 try {
696 mh = (BoundMethodHandle)
697 data.constructor[0].invokeBasic(type, form, (Object) target, (Object) exType, (Object) catcher,
698 (Object) collectArgs, (Object) unboxResult);
699 } catch (Throwable ex) {
700 throw uncaughtException(ex);
701 }
702 assert(mh.type() == type);
703 return mh;
704 }
705
706 /**
707 * Intrinsified during LambdaForm compilation
708 * (see {@link InvokerBytecodeGenerator#emitGuardWithCatch emitGuardWithCatch}).
709 */
710 @LambdaForm.Hidden
711 static Object guardWithCatch(MethodHandle target, Class exType, MethodHandle catcher,
712 Object... av) throws Throwable {
713 int nargs = target.type().parameterCount();
714
715 MethodHandle ctarget = makePairwiseConvert(target, target.type().generic(), 1);
716 MethodHandle gtarget = makeSpreadArguments(ctarget, Object[].class, 0, nargs);
717
718 MethodType ccatcherType = catcher.type().generic()
719 .changeParameterType(0, Throwable.class);
720 MethodHandle ccatcher = makePairwiseConvert(catcher, ccatcherType, 1);
721 MethodHandle gcatcher = makeSpreadArguments(ccatcher, Object[].class, 1, nargs);
722
723 try {
724 return gtarget.invokeExact(av);
725 } catch (Throwable t) {
726 if (!exType.isInstance(t)) throw t;
727 return gcatcher.invokeExact(t, av);
728 }
729 }
730
731 private static MethodHandle GUARD_WITH_CATCH;
732 static MethodHandle guardWithCatch() {
733 if (GUARD_WITH_CATCH != null) {
734 return GUARD_WITH_CATCH;
735 }
736 try {
737 GUARD_WITH_CATCH
738 = IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "guardWithCatch",
739 MethodType.methodType(Object.class, MethodHandle.class, Class.class, MethodHandle.class, Object[].class));
740 } catch (ReflectiveOperationException ex) {
741 throw uncaughtException(ex);
742 }
743 return GUARD_WITH_CATCH;
744 }
745
746 static
747 MethodHandle throwException(MethodType type) {
748 assert(Throwable.class.isAssignableFrom(type.parameterType(0)));
749 int arity = type.parameterCount();
750 if (arity > 1) {
751 return throwException(type.dropParameterTypes(1, arity)).dropArguments(type, 1, arity-1);
752 }
753 return makePairwiseConvert(throwException(), type, 2);
754 }
755
756 static MethodHandle THROW_EXCEPTION;
757 static MethodHandle throwException() {
758 MethodHandle mh = THROW_EXCEPTION;
759 if (mh != null) return mh;
760 try {
761 mh
762 = IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "throwException",
763 MethodType.methodType(Empty.class, Throwable.class));
764 } catch (ReflectiveOperationException ex) {
765 throw uncaughtException(ex);
766 }
767 THROW_EXCEPTION = mh;
768 return mh;
769 }
770 static <T extends Throwable> Empty throwException(T t) throws T { throw t; }
771
772 static MethodHandle[] FAKE_METHOD_HANDLE_INVOKE = new MethodHandle[2];
773 static MethodHandle fakeMethodHandleInvoke(MemberName method) {
774 int idx;
775 assert(method.isMethodHandleInvoke());
776 switch (method.getName()) {
777 case "invoke": idx = 0; break;
778 case "invokeExact": idx = 1; break;
779 default: throw new InternalError(method.getName());
780 }
781 MethodHandle mh = FAKE_METHOD_HANDLE_INVOKE[idx];
782 if (mh != null) return mh;
783 MethodType type = MethodType.methodType(Object.class, UnsupportedOperationException.class,
784 MethodHandle.class, Object[].class);
785 mh = throwException(type);
786 mh = mh.bindTo(new UnsupportedOperationException("cannot reflectively invoke MethodHandle"));
787 if (!method.getInvocationType().equals(mh.type()))
788 throw new InternalError(method.toString());
789 mh = mh.withInternalMemberName(method);
790 mh = mh.asVarargsCollector(Object[].class);
791 assert(method.isVarargs());
792 FAKE_METHOD_HANDLE_INVOKE[idx] = mh;
793 return mh;
794 }
795
796 /**
797 * Create an alias for the method handle which, when called,
798 * appears to be called from the same class loader and protection domain
799 * as hostClass.
800 * This is an expensive no-op unless the method which is called
801 * is sensitive to its caller. A small number of system methods
802 * are in this category, including Class.forName and Method.invoke.
803 */
804 static
805 MethodHandle bindCaller(MethodHandle mh, Class<?> hostClass) {
806 return BindCaller.bindCaller(mh, hostClass);
807 }
808
809 // Put the whole mess into its own nested class.
810 // That way we can lazily load the code and set up the constants.
811 private static class BindCaller {
812 static
813 MethodHandle bindCaller(MethodHandle mh, Class<?> hostClass) {
814 // Do not use this function to inject calls into system classes.
815 if (hostClass == null
816 || (hostClass.isArray() ||
817 hostClass.isPrimitive() ||
818 hostClass.getName().startsWith("java.") ||
819 hostClass.getName().startsWith("sun."))) {
820 throw new InternalError(); // does not happen, and should not anyway
821 }
822 // For simplicity, convert mh to a varargs-like method.
823 MethodHandle vamh = prepareForInvoker(mh);
824 // Cache the result of makeInjectedInvoker once per argument class.
825 MethodHandle bccInvoker = CV_makeInjectedInvoker.get(hostClass);
826 return restoreToType(bccInvoker.bindTo(vamh), mh.type(), mh.internalMemberName(), hostClass);
827 }
828
829 private static MethodHandle makeInjectedInvoker(Class<?> hostClass) {
830 Class<?> bcc = UNSAFE.defineAnonymousClass(hostClass, T_BYTES, null);
831 if (hostClass.getClassLoader() != bcc.getClassLoader())
832 throw new InternalError(hostClass.getName()+" (CL)");
833 try {
834 if (hostClass.getProtectionDomain() != bcc.getProtectionDomain())
835 throw new InternalError(hostClass.getName()+" (PD)");
836 } catch (SecurityException ex) {
837 // Self-check was blocked by security manager. This is OK.
838 // In fact the whole try body could be turned into an assertion.
839 }
840 try {
841 MethodHandle init = IMPL_LOOKUP.findStatic(bcc, "init", MethodType.methodType(void.class));
842 init.invokeExact(); // force initialization of the class
843 } catch (Throwable ex) {
844 throw uncaughtException(ex);
845 }
846 MethodHandle bccInvoker;
847 try {
848 MethodType invokerMT = MethodType.methodType(Object.class, MethodHandle.class, Object[].class);
849 bccInvoker = IMPL_LOOKUP.findStatic(bcc, "invoke_V", invokerMT);
850 } catch (ReflectiveOperationException ex) {
851 throw uncaughtException(ex);
852 }
853 // Test the invoker, to ensure that it really injects into the right place.
854 try {
855 MethodHandle vamh = prepareForInvoker(MH_checkCallerClass);
856 Object ok = bccInvoker.invokeExact(vamh, new Object[]{hostClass, bcc});
857 } catch (Throwable ex) {
858 throw new InternalError(ex);
859 }
860 return bccInvoker;
861 }
862 private static ClassValue<MethodHandle> CV_makeInjectedInvoker = new ClassValue<MethodHandle>() {
863 @Override protected MethodHandle computeValue(Class<?> hostClass) {
864 return makeInjectedInvoker(hostClass);
865 }
866 };
867
868 // Adapt mh so that it can be called directly from an injected invoker:
869 private static MethodHandle prepareForInvoker(MethodHandle mh) {
870 mh = mh.asFixedArity();
871 MethodType mt = mh.type();
872 int arity = mt.parameterCount();
873 MethodHandle vamh = mh.asType(mt.generic());
874 vamh.internalForm().compileToBytecode(); // eliminate LFI stack frames
875 vamh = vamh.asSpreader(Object[].class, arity);
876 vamh.internalForm().compileToBytecode(); // eliminate LFI stack frames
877 return vamh;
878 }
879
880 // Undo the adapter effect of prepareForInvoker:
881 private static MethodHandle restoreToType(MethodHandle vamh, MethodType type,
882 MemberName member,
883 Class<?> hostClass) {
884 MethodHandle mh = vamh.asCollector(Object[].class, type.parameterCount());
885 mh = mh.asType(type);
886 mh = new WrappedMember(mh, type, member, hostClass);
887 return mh;
888 }
889
890 private static final MethodHandle MH_checkCallerClass;
891 static {
892 final Class<?> THIS_CLASS = BindCaller.class;
893 assert(checkCallerClass(THIS_CLASS, THIS_CLASS));
894 try {
895 MH_checkCallerClass = IMPL_LOOKUP
896 .findStatic(THIS_CLASS, "checkCallerClass",
897 MethodType.methodType(boolean.class, Class.class, Class.class));
898 assert((boolean) MH_checkCallerClass.invokeExact(THIS_CLASS, THIS_CLASS));
899 } catch (Throwable ex) {
900 throw new InternalError(ex);
901 }
902 }
903
904 @CallerSensitive
905 private static boolean checkCallerClass(Class<?> expected, Class<?> expected2) {
906 // This method is called via MH_checkCallerClass and so it's
907 // correct to ask for the immediate caller here.
908 Class<?> actual = Reflection.getCallerClass();
909 if (actual != expected && actual != expected2)
910 throw new InternalError("found "+actual.getName()+", expected "+expected.getName()
911 +(expected == expected2 ? "" : ", or else "+expected2.getName()));
912 return true;
913 }
914
915 private static final byte[] T_BYTES;
916 static {
917 final Object[] values = {null};
918 AccessController.doPrivileged(new PrivilegedAction<Void>() {
919 public Void run() {
920 try {
921 Class<T> tClass = T.class;
922 String tName = tClass.getName();
923 String tResource = tName.substring(tName.lastIndexOf('.')+1)+".class";
924 java.net.URLConnection uconn = tClass.getResource(tResource).openConnection();
925 int len = uconn.getContentLength();
926 byte[] bytes = new byte[len];
927 try (java.io.InputStream str = uconn.getInputStream()) {
928 int nr = str.read(bytes);
929 if (nr != len) throw new java.io.IOException(tResource);
930 }
931 values[0] = bytes;
932 } catch (java.io.IOException ex) {
933 throw new InternalError(ex);
934 }
935 return null;
936 }
937 });
938 T_BYTES = (byte[]) values[0];
939 }
940
941 // The following class is used as a template for Unsafe.defineAnonymousClass:
942 private static class T {
943 static void init() { } // side effect: initializes this class
944 static Object invoke_V(MethodHandle vamh, Object[] args) throws Throwable {
945 return vamh.invokeExact(args);
946 }
947 }
948 }
949
950
951 /** This subclass allows a wrapped method handle to be re-associated with an arbitrary member name. */
952 static class WrappedMember extends MethodHandle {
953 private final MethodHandle target;
954 private final MemberName member;
955 private final Class<?> callerClass;
956
957 private WrappedMember(MethodHandle target, MethodType type, MemberName member, Class<?> callerClass) {
958 super(type, reinvokerForm(target));
959 this.target = target;
960 this.member = member;
961 this.callerClass = callerClass;
962 }
963
964 @Override
965 MethodHandle reinvokerTarget() {
966 return target;
967 }
968 @Override
969 public MethodHandle asTypeUncached(MethodType newType) {
970 // This MH is an alias for target, except for the MemberName
971 // Drop the MemberName if there is any conversion.
972 return asTypeCache = target.asType(newType);
973 }
974 @Override
975 MemberName internalMemberName() {
976 return member;
977 }
978 @Override
979 Class<?> internalCallerClass() {
980 return callerClass;
981 }
982 @Override
983 boolean isInvokeSpecial() {
984 return target.isInvokeSpecial();
985 }
986 @Override
987 MethodHandle viewAsType(MethodType newType) {
988 return new WrappedMember(target, newType, member, callerClass);
989 }
990 }
991
992 static MethodHandle makeWrappedMember(MethodHandle target, MemberName member) {
993 if (member.equals(target.internalMemberName()))
994 return target;
995 return new WrappedMember(target, target.type(), member, null);
996 }
997
998 }