1 /*
2 * Copyright (c) 2008, 2018, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package java.lang.invoke;
27
28 import jdk.internal.ref.CleanerFactory;
29 import sun.invoke.util.Wrapper;
30
31 import java.lang.invoke.MethodHandles.Lookup;
32 import java.lang.reflect.Field;
33
34 import static java.lang.invoke.MethodHandleNatives.Constants.*;
35 import static java.lang.invoke.MethodHandleStatics.TRACE_METHOD_LINKAGE;
36 import static java.lang.invoke.MethodHandles.Lookup.IMPL_LOOKUP;
37
38 /**
39 * The JVM interface for the method handles package is all here.
40 * This is an interface internal and private to an implementation of JSR 292.
41 * <em>This class is not part of the JSR 292 standard.</em>
42 * @author jrose
43 */
44 class MethodHandleNatives {
45
46 private MethodHandleNatives() { } // static only
47
48 /// MemberName support
49
50 static native void init(MemberName self, Object ref);
51 static native void expand(MemberName self);
52 static native MemberName resolve(MemberName self, Class<?> caller) throws LinkageError, ClassNotFoundException;
53 static native int getMembers(Class<?> defc, String matchName, String matchSig,
54 int matchFlags, Class<?> caller, int skip, MemberName[] results);
55
56 /// Field layout queries parallel to jdk.internal.misc.Unsafe:
57 static native long objectFieldOffset(MemberName self); // e.g., returns vmindex
58 static native long staticFieldOffset(MemberName self); // e.g., returns vmindex
59 static native Object staticFieldBase(MemberName self); // e.g., returns clazz
60 static native Object getMemberVMInfo(MemberName self); // returns {vmindex,vmtarget}
61
62 /// CallSite support
63
64 /** Tell the JVM that we need to change the target of a CallSite. */
65 static native void setCallSiteTargetNormal(CallSite site, MethodHandle target);
66 static native void setCallSiteTargetVolatile(CallSite site, MethodHandle target);
67
68 static native void copyOutBootstrapArguments(Class<?> caller, int[] indexInfo,
69 int start, int end,
70 Object[] buf, int pos,
71 boolean resolve,
72 Object ifNotAvailable);
73
74 /** Represents a context to track nmethod dependencies on CallSite instance target. */
75 static class CallSiteContext implements Runnable {
76 //@Injected JVM_nmethodBucket* vmdependencies;
77
78 static CallSiteContext make(CallSite cs) {
79 final CallSiteContext newContext = new CallSiteContext();
80 // CallSite instance is tracked by a Cleanable which clears native
81 // structures allocated for CallSite context. Though the CallSite can
82 // become unreachable, its Context is retained by the Cleanable instance
83 // (which is referenced from Cleaner instance which is referenced from
84 // CleanerFactory class) until cleanup is performed.
85 CleanerFactory.cleaner().register(cs, newContext);
86 return newContext;
87 }
88
89 @Override
90 public void run() {
91 MethodHandleNatives.clearCallSiteContext(this);
92 }
93 }
94
95 /** Invalidate all recorded nmethods. */
96 private static native void clearCallSiteContext(CallSiteContext context);
97
98 private static native void registerNatives();
99 static {
100 registerNatives();
101 }
102
103 /**
104 * Compile-time constants go here. This collection exists not only for
105 * reference from clients, but also for ensuring the VM and JDK agree on the
106 * values of these constants (see {@link #verifyConstants()}).
107 */
108 static class Constants {
109 Constants() { } // static only
110
111 static final int
112 MN_IS_METHOD = 0x00010000, // method (not constructor)
113 MN_IS_CONSTRUCTOR = 0x00020000, // constructor
114 MN_IS_FIELD = 0x00040000, // field
115 MN_IS_TYPE = 0x00080000, // nested type
116 MN_CALLER_SENSITIVE = 0x00100000, // @CallerSensitive annotation detected
117 MN_REFERENCE_KIND_SHIFT = 24, // refKind
118 MN_REFERENCE_KIND_MASK = 0x0F000000 >> MN_REFERENCE_KIND_SHIFT,
119 // The SEARCH_* bits are not for MN.flags but for the matchFlags argument of MHN.getMembers:
120 MN_SEARCH_SUPERCLASSES = 0x00100000,
121 MN_SEARCH_INTERFACES = 0x00200000;
122
123 /**
124 * Constant pool reference-kind codes, as used by CONSTANT_MethodHandle CP entries.
125 */
126 static final byte
127 REF_NONE = 0, // null value
128 REF_getField = 1,
129 REF_getStatic = 2,
130 REF_putField = 3,
131 REF_putStatic = 4,
132 REF_invokeVirtual = 5,
133 REF_invokeStatic = 6,
134 REF_invokeSpecial = 7,
135 REF_newInvokeSpecial = 8,
136 REF_invokeInterface = 9,
137 REF_LIMIT = 10;
138 }
139
140 static boolean refKindIsValid(int refKind) {
141 return (refKind > REF_NONE && refKind < REF_LIMIT);
142 }
143 static boolean refKindIsField(byte refKind) {
144 assert(refKindIsValid(refKind));
145 return (refKind <= REF_putStatic);
146 }
147 static boolean refKindIsGetter(byte refKind) {
148 assert(refKindIsValid(refKind));
149 return (refKind <= REF_getStatic);
150 }
151 static boolean refKindIsSetter(byte refKind) {
152 return refKindIsField(refKind) && !refKindIsGetter(refKind);
153 }
154 static boolean refKindIsMethod(byte refKind) {
155 return !refKindIsField(refKind) && (refKind != REF_newInvokeSpecial);
156 }
157 static boolean refKindIsConstructor(byte refKind) {
158 return (refKind == REF_newInvokeSpecial);
159 }
160 static boolean refKindHasReceiver(byte refKind) {
161 assert(refKindIsValid(refKind));
162 return (refKind & 1) != 0;
163 }
164 static boolean refKindIsStatic(byte refKind) {
165 return !refKindHasReceiver(refKind) && (refKind != REF_newInvokeSpecial);
166 }
167 static boolean refKindDoesDispatch(byte refKind) {
168 assert(refKindIsValid(refKind));
169 return (refKind == REF_invokeVirtual ||
170 refKind == REF_invokeInterface);
171 }
172 static {
173 final int HR_MASK = ((1 << REF_getField) |
174 (1 << REF_putField) |
175 (1 << REF_invokeVirtual) |
176 (1 << REF_invokeSpecial) |
177 (1 << REF_invokeInterface)
178 );
179 for (byte refKind = REF_NONE+1; refKind < REF_LIMIT; refKind++) {
180 assert(refKindHasReceiver(refKind) == (((1<<refKind) & HR_MASK) != 0)) : refKind;
181 }
182 }
183 static String refKindName(byte refKind) {
184 assert(refKindIsValid(refKind));
185 switch (refKind) {
186 case REF_getField: return "getField";
187 case REF_getStatic: return "getStatic";
188 case REF_putField: return "putField";
189 case REF_putStatic: return "putStatic";
190 case REF_invokeVirtual: return "invokeVirtual";
191 case REF_invokeStatic: return "invokeStatic";
192 case REF_invokeSpecial: return "invokeSpecial";
193 case REF_newInvokeSpecial: return "newInvokeSpecial";
194 case REF_invokeInterface: return "invokeInterface";
195 default: return "REF_???";
196 }
197 }
198
199 private static native int getNamedCon(int which, Object[] name);
200 static boolean verifyConstants() {
201 Object[] box = { null };
202 for (int i = 0; ; i++) {
203 box[0] = null;
204 int vmval = getNamedCon(i, box);
205 if (box[0] == null) break;
206 String name = (String) box[0];
207 try {
208 Field con = Constants.class.getDeclaredField(name);
209 int jval = con.getInt(null);
210 if (jval == vmval) continue;
211 String err = (name+": JVM has "+vmval+" while Java has "+jval);
212 if (name.equals("CONV_OP_LIMIT")) {
213 System.err.println("warning: "+err);
214 continue;
215 }
216 throw new InternalError(err);
217 } catch (NoSuchFieldException | IllegalAccessException ex) {
218 String err = (name+": JVM has "+vmval+" which Java does not define");
219 // ignore exotic ops the JVM cares about; we just wont issue them
220 //System.err.println("warning: "+err);
221 continue;
222 }
223 }
224 return true;
225 }
226 static {
227 assert(verifyConstants());
228 }
229
230 // Up-calls from the JVM.
231 // These must NOT be public.
232
233 /**
234 * The JVM is linking an invokedynamic instruction. Create a reified call site for it.
235 */
236 static MemberName linkCallSite(Object callerObj,
237 int indexInCP,
238 Object bootstrapMethodObj,
239 Object nameObj, Object typeObj,
240 Object staticArguments,
241 Object[] appendixResult) {
242 MethodHandle bootstrapMethod = (MethodHandle)bootstrapMethodObj;
243 Class<?> caller = (Class<?>)callerObj;
244 String name = nameObj.toString().intern();
245 MethodType type = (MethodType)typeObj;
246 if (!TRACE_METHOD_LINKAGE)
247 return linkCallSiteImpl(caller, bootstrapMethod, name, type,
248 staticArguments, appendixResult);
249 return linkCallSiteTracing(caller, bootstrapMethod, name, type,
250 staticArguments, appendixResult);
251 }
252 static MemberName linkCallSiteImpl(Class<?> caller,
253 MethodHandle bootstrapMethod,
254 String name, MethodType type,
255 Object staticArguments,
256 Object[] appendixResult) {
257 CallSite callSite = CallSite.makeSite(bootstrapMethod,
258 name,
259 type,
260 staticArguments,
261 caller);
262 if (callSite instanceof ConstantCallSite) {
263 appendixResult[0] = callSite.dynamicInvoker();
264 return Invokers.linkToTargetMethod(type);
265 } else {
266 appendixResult[0] = callSite;
267 return Invokers.linkToCallSiteMethod(type);
268 }
269 }
270 // Tracing logic:
271 static MemberName linkCallSiteTracing(Class<?> caller,
272 MethodHandle bootstrapMethod,
273 String name, MethodType type,
274 Object staticArguments,
275 Object[] appendixResult) {
276 Object bsmReference = bootstrapMethod.internalMemberName();
277 if (bsmReference == null) bsmReference = bootstrapMethod;
278 String staticArglist = staticArglistForTrace(staticArguments);
279 System.out.println("linkCallSite "+caller.getName()+" "+
280 bsmReference+" "+
281 name+type+"/"+staticArglist);
282 try {
283 MemberName res = linkCallSiteImpl(caller, bootstrapMethod, name, type,
284 staticArguments, appendixResult);
285 System.out.println("linkCallSite => "+res+" + "+appendixResult[0]);
286 return res;
287 } catch (Throwable ex) {
288 ex.printStackTrace(); // print now in case exception is swallowed
289 System.out.println("linkCallSite => throw "+ex);
290 throw ex;
291 }
292 }
293
294 // this implements the upcall from the JVM, MethodHandleNatives.linkDynamicConstant:
295 static Object linkDynamicConstant(Object callerObj,
296 int indexInCP,
297 Object bootstrapMethodObj,
298 Object nameObj, Object typeObj,
299 Object staticArguments) {
300 MethodHandle bootstrapMethod = (MethodHandle)bootstrapMethodObj;
301 Class<?> caller = (Class<?>)callerObj;
302 String name = nameObj.toString().intern();
303 Class<?> type = (Class<?>)typeObj;
304 if (!TRACE_METHOD_LINKAGE)
305 return linkDynamicConstantImpl(caller, bootstrapMethod, name, type, staticArguments);
306 return linkDynamicConstantTracing(caller, bootstrapMethod, name, type, staticArguments);
307 }
308
309 static Object linkDynamicConstantImpl(Class<?> caller,
310 MethodHandle bootstrapMethod,
311 String name, Class<?> type,
312 Object staticArguments) {
313 return ConstantBootstraps.makeConstant(bootstrapMethod, name, type, staticArguments, caller);
314 }
315
316 private static String staticArglistForTrace(Object staticArguments) {
317 if (staticArguments instanceof Object[])
318 return "BSA="+java.util.Arrays.asList((Object[]) staticArguments);
319 if (staticArguments instanceof int[])
320 return "BSA@"+java.util.Arrays.toString((int[]) staticArguments);
321 if (staticArguments == null)
322 return "BSA0=null";
323 return "BSA1="+staticArguments;
324 }
325
326 // Tracing logic:
327 static Object linkDynamicConstantTracing(Class<?> caller,
328 MethodHandle bootstrapMethod,
329 String name, Class<?> type,
330 Object staticArguments) {
331 Object bsmReference = bootstrapMethod.internalMemberName();
332 if (bsmReference == null) bsmReference = bootstrapMethod;
333 String staticArglist = staticArglistForTrace(staticArguments);
334 System.out.println("linkDynamicConstant "+caller.getName()+" "+
335 bsmReference+" "+
336 name+type+"/"+staticArglist);
337 try {
338 Object res = linkDynamicConstantImpl(caller, bootstrapMethod, name, type, staticArguments);
339 System.out.println("linkDynamicConstantImpl => "+res);
340 return res;
341 } catch (Throwable ex) {
342 ex.printStackTrace(); // print now in case exception is swallowed
343 System.out.println("linkDynamicConstant => throw "+ex);
344 throw ex;
345 }
346 }
347
348 /** The JVM is requesting pull-mode bootstrap when it provides
349 * a tuple of the form int[]{ argc, vmindex }.
350 * The BSM is expected to call back to the JVM using the caller
351 * class and vmindex to resolve the static arguments.
352 */
353 static boolean staticArgumentsPulled(Object staticArguments) {
354 return staticArguments instanceof int[];
355 }
356
357 /** A BSM runs in pull-mode if and only if its sole arguments
358 * are (Lookup, BootstrapCallInfo), or can be converted pairwise
359 * to those types, and it is not of variable arity.
360 * Excluding error cases, we can just test that the arity is a constant 2.
361 *
362 * NOTE: This method currently returns false, since pulling is not currently
363 * exposed to a BSM. When pull mode is supported the method block will be
364 * replaced with currently commented out code.
365 */
366 static boolean isPullModeBSM(MethodHandle bsm) {
367 return false;
368 // return bsm.type().parameterCount() == 2 && !bsm.isVarargsCollector();
369 }
370
371 /**
372 * The JVM wants a pointer to a MethodType. Oblige it by finding or creating one.
373 */
374 static MethodType findMethodHandleType(Class<?> rtype, Class<?>[] ptypes) {
375 return MethodType.makeImpl(rtype, ptypes, true);
376 }
377
378 /**
379 * The JVM wants to link a call site that requires a dynamic type check.
380 * Name is a type-checking invoker, invokeExact or invoke.
381 * Return a JVM method (MemberName) to handle the invoking.
382 * The method assumes the following arguments on the stack:
383 * 0: the method handle being invoked
384 * 1-N: the arguments to the method handle invocation
385 * N+1: an optional, implicitly added argument (typically the given MethodType)
386 * <p>
387 * The nominal method at such a call site is an instance of
388 * a signature-polymorphic method (see @PolymorphicSignature).
389 * Such method instances are user-visible entities which are
390 * "split" from the generic placeholder method in {@code MethodHandle}.
391 * (Note that the placeholder method is not identical with any of
392 * its instances. If invoked reflectively, is guaranteed to throw an
393 * {@code UnsupportedOperationException}.)
394 * If the signature-polymorphic method instance is ever reified,
395 * it appears as a "copy" of the original placeholder
396 * (a native final member of {@code MethodHandle}) except
397 * that its type descriptor has shape required by the instance,
398 * and the method instance is <em>not</em> varargs.
399 * The method instance is also marked synthetic, since the
400 * method (by definition) does not appear in Java source code.
401 * <p>
402 * The JVM is allowed to reify this method as instance metadata.
403 * For example, {@code invokeBasic} is always reified.
404 * But the JVM may instead call {@code linkMethod}.
405 * If the result is an * ordered pair of a {@code (method, appendix)},
406 * the method gets all the arguments (0..N inclusive)
407 * plus the appendix (N+1), and uses the appendix to complete the call.
408 * In this way, one reusable method (called a "linker method")
409 * can perform the function of any number of polymorphic instance
410 * methods.
411 * <p>
412 * Linker methods are allowed to be weakly typed, with any or
413 * all references rewritten to {@code Object} and any primitives
414 * (except {@code long}/{@code float}/{@code double})
415 * rewritten to {@code int}.
416 * A linker method is trusted to return a strongly typed result,
417 * according to the specific method type descriptor of the
418 * signature-polymorphic instance it is emulating.
419 * This can involve (as necessary) a dynamic check using
420 * data extracted from the appendix argument.
421 * <p>
422 * The JVM does not inspect the appendix, other than to pass
423 * it verbatim to the linker method at every call.
424 * This means that the JDK runtime has wide latitude
425 * for choosing the shape of each linker method and its
426 * corresponding appendix.
427 * Linker methods should be generated from {@code LambdaForm}s
428 * so that they do not become visible on stack traces.
429 * <p>
430 * The {@code linkMethod} call is free to omit the appendix
431 * (returning null) and instead emulate the required function
432 * completely in the linker method.
433 * As a corner case, if N==255, no appendix is possible.
434 * In this case, the method returned must be custom-generated to
435 * to perform any needed type checking.
436 * <p>
437 * If the JVM does not reify a method at a call site, but instead
438 * calls {@code linkMethod}, the corresponding call represented
439 * in the bytecodes may mention a valid method which is not
440 * representable with a {@code MemberName}.
441 * Therefore, use cases for {@code linkMethod} tend to correspond to
442 * special cases in reflective code such as {@code findVirtual}
443 * or {@code revealDirect}.
444 */
445 static MemberName linkMethod(Class<?> callerClass, int refKind,
446 Class<?> defc, String name, Object type,
447 Object[] appendixResult) {
448 if (!TRACE_METHOD_LINKAGE)
449 return linkMethodImpl(callerClass, refKind, defc, name, type, appendixResult);
450 return linkMethodTracing(callerClass, refKind, defc, name, type, appendixResult);
451 }
452 static MemberName linkMethodImpl(Class<?> callerClass, int refKind,
453 Class<?> defc, String name, Object type,
454 Object[] appendixResult) {
455 try {
456 if (refKind == REF_invokeVirtual) {
457 if (defc == MethodHandle.class) {
458 return Invokers.methodHandleInvokeLinkerMethod(
459 name, fixMethodType(callerClass, type), appendixResult);
460 } else if (defc == VarHandle.class) {
461 return varHandleOperationLinkerMethod(
462 name, fixMethodType(callerClass, type), appendixResult);
463 }
464 }
465 } catch (Error e) {
466 // Pass through an Error, including say StackOverflowError or
467 // OutOfMemoryError
468 throw e;
469 } catch (Throwable ex) {
470 // Wrap anything else in LinkageError
471 throw new LinkageError(ex.getMessage(), ex);
472 }
473 throw new LinkageError("no such method "+defc.getName()+"."+name+type);
474 }
475 private static MethodType fixMethodType(Class<?> callerClass, Object type) {
476 if (type instanceof MethodType)
477 return (MethodType) type;
478 else
479 return MethodType.fromDescriptor((String)type, callerClass.getClassLoader());
480 }
481 // Tracing logic:
482 static MemberName linkMethodTracing(Class<?> callerClass, int refKind,
483 Class<?> defc, String name, Object type,
484 Object[] appendixResult) {
485 System.out.println("linkMethod "+defc.getName()+"."+
486 name+type+"/"+Integer.toHexString(refKind));
487 try {
488 MemberName res = linkMethodImpl(callerClass, refKind, defc, name, type, appendixResult);
489 System.out.println("linkMethod => "+res+" + "+appendixResult[0]);
490 return res;
491 } catch (Throwable ex) {
492 System.out.println("linkMethod => throw "+ex);
493 throw ex;
494 }
495 }
496
497 /**
498 * Obtain the method to link to the VarHandle operation.
499 * This method is located here and not in Invokers to avoid
500 * intializing that and other classes early on in VM bootup.
501 */
502 private static MemberName varHandleOperationLinkerMethod(String name,
503 MethodType mtype,
504 Object[] appendixResult) {
505 // Get the signature method type
506 final MethodType sigType = mtype.basicType();
507
508 // Get the access kind from the method name
509 VarHandle.AccessMode ak;
510 try {
511 ak = VarHandle.AccessMode.valueFromMethodName(name);
512 } catch (IllegalArgumentException e) {
513 throw MethodHandleStatics.newInternalError(e);
514 }
515
516 // Create the appendix descriptor constant
517 VarHandle.AccessDescriptor ad = new VarHandle.AccessDescriptor(mtype, ak.at.ordinal(), ak.ordinal());
518 appendixResult[0] = ad;
519
520 if (MethodHandleStatics.VAR_HANDLE_GUARDS) {
521 // If not polymorphic in the return type, such as the compareAndSet
522 // methods that return boolean
523 Class<?> guardReturnType = sigType.returnType();
524 if (ak.at.isMonomorphicInReturnType) {
525 if (ak.at.returnType != mtype.returnType()) {
526 // The caller contains a different return type than that
527 // defined by the method
528 throw newNoSuchMethodErrorOnVarHandle(name, mtype);
529 }
530 // Adjust the return type of the signature method type
531 guardReturnType = ak.at.returnType;
532 }
533
534 // Get the guard method type for linking
535 final Class<?>[] guardParams = new Class<?>[sigType.parameterCount() + 2];
536 // VarHandle at start
537 guardParams[0] = VarHandle.class;
538 for (int i = 0; i < sigType.parameterCount(); i++) {
539 guardParams[i + 1] = sigType.parameterType(i);
540 }
541 // Access descriptor at end
542 guardParams[guardParams.length - 1] = VarHandle.AccessDescriptor.class;
543 MethodType guardType = MethodType.makeImpl(guardReturnType, guardParams, true);
544
545 MemberName linker = new MemberName(
546 VarHandleGuards.class, getVarHandleGuardMethodName(guardType),
547 guardType, REF_invokeStatic);
548
549 linker = MemberName.getFactory().resolveOrNull(REF_invokeStatic, linker,
550 VarHandleGuards.class);
551 if (linker != null) {
552 return linker;
553 }
554 // Fall back to lambda form linkage if guard method is not available
555 // TODO Optionally log fallback ?
556 }
557 return Invokers.varHandleInvokeLinkerMethod(ak, mtype);
558 }
559 static String getVarHandleGuardMethodName(MethodType guardType) {
560 String prefix = "guard_";
561 StringBuilder sb = new StringBuilder(prefix.length() + guardType.parameterCount());
562
563 sb.append(prefix);
564 for (int i = 1; i < guardType.parameterCount() - 1; i++) {
565 Class<?> pt = guardType.parameterType(i);
566 sb.append(getCharType(pt));
567 }
568 sb.append('_').append(getCharType(guardType.returnType()));
569 return sb.toString();
570 }
571 static char getCharType(Class<?> pt) {
572 return Wrapper.forBasicType(pt).basicTypeChar();
573 }
574 static NoSuchMethodError newNoSuchMethodErrorOnVarHandle(String name, MethodType mtype) {
575 return new NoSuchMethodError("VarHandle." + name + mtype);
576 }
577
578 /**
579 * The JVM is resolving a CONSTANT_MethodHandle CP entry. And it wants our help.
580 * It will make an up-call to this method. (Do not change the name or signature.)
581 * The type argument is a Class for field requests and a MethodType for non-fields.
582 * <p>
583 * Recent versions of the JVM may also pass a resolved MemberName for the type.
584 * In that case, the name is ignored and may be null.
585 */
586 static MethodHandle linkMethodHandleConstant(Class<?> callerClass, int refKind,
587 Class<?> defc, String name, Object type) {
588 try {
589 Lookup lookup = IMPL_LOOKUP.in(callerClass);
590 assert(refKindIsValid(refKind));
591 return lookup.linkMethodHandleConstant((byte) refKind, defc, name, type);
592 } catch (ReflectiveOperationException ex) {
593 throw mapLookupExceptionToError(ex);
594 }
595 }
596
597 /**
598 * Map a reflective exception to a linkage error.
599 */
600 static LinkageError mapLookupExceptionToError(ReflectiveOperationException ex) {
601 LinkageError err;
602 if (ex instanceof IllegalAccessException) {
603 Throwable cause = ex.getCause();
604 if (cause instanceof AbstractMethodError) {
605 return (AbstractMethodError) cause;
606 } else {
607 err = new IllegalAccessError(ex.getMessage());
608 }
609 } else if (ex instanceof NoSuchMethodException) {
610 err = new NoSuchMethodError(ex.getMessage());
611 } else if (ex instanceof NoSuchFieldException) {
612 err = new NoSuchFieldError(ex.getMessage());
613 } else {
614 err = new IncompatibleClassChangeError();
615 }
616 return initCauseFrom(err, ex);
617 }
618
619 /**
620 * Use best possible cause for err.initCause(), substituting the
621 * cause for err itself if the cause has the same (or better) type.
622 */
623 static <E extends Error> E initCauseFrom(E err, Exception ex) {
624 Throwable th = ex.getCause();
625 @SuppressWarnings("unchecked")
626 final Class<E> Eclass = (Class<E>) err.getClass();
627 if (Eclass.isInstance(th))
628 return Eclass.cast(th);
629 err.initCause(th == null ? ex : th);
630 return err;
631 }
632
633 /**
634 * Is this method a caller-sensitive method?
635 * I.e., does it call Reflection.getCallerClass or a similar method
636 * to ask about the identity of its caller?
637 */
638 static boolean isCallerSensitive(MemberName mem) {
639 if (!mem.isInvocable()) return false; // fields are not caller sensitive
640
641 return mem.isCallerSensitive() || canBeCalledVirtual(mem);
642 }
643
644 static boolean canBeCalledVirtual(MemberName mem) {
645 assert(mem.isInvocable());
646 switch (mem.getName()) {
647 case "getContextClassLoader":
648 return canBeCalledVirtual(mem, java.lang.Thread.class);
649 }
650 return false;
651 }
652
653 static boolean canBeCalledVirtual(MemberName symbolicRef, Class<?> definingClass) {
654 Class<?> symbolicRefClass = symbolicRef.getDeclaringClass();
655 if (symbolicRefClass == definingClass) return true;
656 if (symbolicRef.isStatic() || symbolicRef.isPrivate()) return false;
657 return (definingClass.isAssignableFrom(symbolicRefClass) || // Msym overrides Mdef
658 symbolicRefClass.isInterface()); // Mdef implements Msym
659 }
660 }