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,
53 boolean speculativeResolve) throws LinkageError, ClassNotFoundException;
54 static native int getMembers(Class<?> defc, String matchName, String matchSig,
55 int matchFlags, Class<?> caller, int skip, MemberName[] results);
56
57 /// Field layout queries parallel to jdk.internal.misc.Unsafe:
58 static native long objectFieldOffset(MemberName self); // e.g., returns vmindex
59 static native long staticFieldOffset(MemberName self); // e.g., returns vmindex
60 static native Object staticFieldBase(MemberName self); // e.g., returns clazz
61 static native Object getMemberVMInfo(MemberName self); // returns {vmindex,vmtarget}
62
63 /// CallSite support
64
65 /** Tell the JVM that we need to change the target of a CallSite. */
66 static native void setCallSiteTargetNormal(CallSite site, MethodHandle target);
67 static native void setCallSiteTargetVolatile(CallSite site, MethodHandle target);
68
69 static native void copyOutBootstrapArguments(Class<?> caller, int[] indexInfo,
70 int start, int end,
71 Object[] buf, int pos,
72 boolean resolve,
73 Object ifNotAvailable);
74
75 /** Represents a context to track nmethod dependencies on CallSite instance target. */
76 static class CallSiteContext implements Runnable {
77 //@Injected JVM_nmethodBucket* vmdependencies;
78
79 static CallSiteContext make(CallSite cs) {
80 final CallSiteContext newContext = new CallSiteContext();
81 // CallSite instance is tracked by a Cleanable which clears native
82 // structures allocated for CallSite context. Though the CallSite can
83 // become unreachable, its Context is retained by the Cleanable instance
84 // (which is referenced from Cleaner instance which is referenced from
85 // CleanerFactory class) until cleanup is performed.
86 CleanerFactory.cleaner().register(cs, newContext);
87 return newContext;
88 }
89
90 @Override
91 public void run() {
92 MethodHandleNatives.clearCallSiteContext(this);
93 }
94 }
95
96 /** Invalidate all recorded nmethods. */
97 private static native void clearCallSiteContext(CallSiteContext context);
98
99 private static native void registerNatives();
100 static {
101 registerNatives();
102 }
103
104 /**
105 * Compile-time constants go here. This collection exists not only for
106 * reference from clients, but also for ensuring the VM and JDK agree on the
107 * values of these constants (see {@link #verifyConstants()}).
108 */
109 static class Constants {
110 Constants() { } // static only
111
112 static final int
113 MN_IS_METHOD = 0x00010000, // method (not constructor)
114 MN_IS_CONSTRUCTOR = 0x00020000, // constructor
115 MN_IS_FIELD = 0x00040000, // field
116 MN_IS_TYPE = 0x00080000, // nested type
117 MN_CALLER_SENSITIVE = 0x00100000, // @CallerSensitive annotation detected
118 MN_REFERENCE_KIND_SHIFT = 24, // refKind
119 MN_REFERENCE_KIND_MASK = 0x0F000000 >> MN_REFERENCE_KIND_SHIFT,
120 // The SEARCH_* bits are not for MN.flags but for the matchFlags argument of MHN.getMembers:
121 MN_SEARCH_SUPERCLASSES = 0x00100000,
122 MN_SEARCH_INTERFACES = 0x00200000;
123
124 /**
125 * Constant pool reference-kind codes, as used by CONSTANT_MethodHandle CP entries.
126 */
127 static final byte
128 REF_NONE = 0, // null value
129 REF_getField = 1,
130 REF_getStatic = 2,
131 REF_putField = 3,
132 REF_putStatic = 4,
133 REF_invokeVirtual = 5,
134 REF_invokeStatic = 6,
135 REF_invokeSpecial = 7,
136 REF_newInvokeSpecial = 8,
137 REF_invokeInterface = 9,
138 REF_LIMIT = 10;
139 }
140
141 static boolean refKindIsValid(int refKind) {
142 return (refKind > REF_NONE && refKind < REF_LIMIT);
143 }
144 static boolean refKindIsField(byte refKind) {
145 assert(refKindIsValid(refKind));
146 return (refKind <= REF_putStatic);
147 }
148 static boolean refKindIsGetter(byte refKind) {
149 assert(refKindIsValid(refKind));
150 return (refKind <= REF_getStatic);
151 }
152 static boolean refKindIsSetter(byte refKind) {
153 return refKindIsField(refKind) && !refKindIsGetter(refKind);
154 }
155 static boolean refKindIsMethod(byte refKind) {
156 return !refKindIsField(refKind) && (refKind != REF_newInvokeSpecial);
157 }
158 static boolean refKindIsConstructor(byte refKind) {
159 return (refKind == REF_newInvokeSpecial);
160 }
161 static boolean refKindHasReceiver(byte refKind) {
162 assert(refKindIsValid(refKind));
163 return (refKind & 1) != 0;
164 }
165 static boolean refKindIsStatic(byte refKind) {
166 return !refKindHasReceiver(refKind) && (refKind != REF_newInvokeSpecial);
167 }
168 static boolean refKindDoesDispatch(byte refKind) {
169 assert(refKindIsValid(refKind));
170 return (refKind == REF_invokeVirtual ||
171 refKind == REF_invokeInterface);
172 }
173 static {
174 final int HR_MASK = ((1 << REF_getField) |
175 (1 << REF_putField) |
176 (1 << REF_invokeVirtual) |
177 (1 << REF_invokeSpecial) |
178 (1 << REF_invokeInterface)
179 );
180 for (byte refKind = REF_NONE+1; refKind < REF_LIMIT; refKind++) {
181 assert(refKindHasReceiver(refKind) == (((1<<refKind) & HR_MASK) != 0)) : refKind;
182 }
183 }
184 static String refKindName(byte refKind) {
185 assert(refKindIsValid(refKind));
186 switch (refKind) {
187 case REF_getField: return "getField";
188 case REF_getStatic: return "getStatic";
189 case REF_putField: return "putField";
190 case REF_putStatic: return "putStatic";
191 case REF_invokeVirtual: return "invokeVirtual";
192 case REF_invokeStatic: return "invokeStatic";
193 case REF_invokeSpecial: return "invokeSpecial";
194 case REF_newInvokeSpecial: return "newInvokeSpecial";
195 case REF_invokeInterface: return "invokeInterface";
196 default: return "REF_???";
197 }
198 }
199
200 private static native int getNamedCon(int which, Object[] name);
201 static boolean verifyConstants() {
202 Object[] box = { null };
203 for (int i = 0; ; i++) {
204 box[0] = null;
205 int vmval = getNamedCon(i, box);
206 if (box[0] == null) break;
207 String name = (String) box[0];
208 try {
209 Field con = Constants.class.getDeclaredField(name);
210 int jval = con.getInt(null);
211 if (jval == vmval) continue;
212 String err = (name+": JVM has "+vmval+" while Java has "+jval);
213 if (name.equals("CONV_OP_LIMIT")) {
214 System.err.println("warning: "+err);
215 continue;
216 }
217 throw new InternalError(err);
218 } catch (NoSuchFieldException | IllegalAccessException ex) {
219 String err = (name+": JVM has "+vmval+" which Java does not define");
220 // ignore exotic ops the JVM cares about; we just wont issue them
221 //System.err.println("warning: "+err);
222 continue;
223 }
224 }
225 return true;
226 }
227 static {
228 assert(verifyConstants());
229 }
230
231 // Up-calls from the JVM.
232 // These must NOT be public.
233
234 /**
235 * The JVM is linking an invokedynamic instruction. Create a reified call site for it.
236 */
237 static MemberName linkCallSite(Object callerObj,
238 int indexInCP,
239 Object bootstrapMethodObj,
240 Object nameObj, Object typeObj,
241 Object staticArguments,
242 Object[] appendixResult) {
243 MethodHandle bootstrapMethod = (MethodHandle)bootstrapMethodObj;
244 Class<?> caller = (Class<?>)callerObj;
245 String name = nameObj.toString().intern();
246 MethodType type = (MethodType)typeObj;
247 if (!TRACE_METHOD_LINKAGE)
248 return linkCallSiteImpl(caller, bootstrapMethod, name, type,
249 staticArguments, appendixResult);
250 return linkCallSiteTracing(caller, bootstrapMethod, name, type,
251 staticArguments, appendixResult);
252 }
253 static MemberName linkCallSiteImpl(Class<?> caller,
254 MethodHandle bootstrapMethod,
255 String name, MethodType type,
256 Object staticArguments,
257 Object[] appendixResult) {
258 CallSite callSite = CallSite.makeSite(bootstrapMethod,
259 name,
260 type,
261 staticArguments,
262 caller);
263 if (callSite instanceof ConstantCallSite) {
264 appendixResult[0] = callSite.dynamicInvoker();
265 return Invokers.linkToTargetMethod(type);
266 } else {
267 appendixResult[0] = callSite;
268 return Invokers.linkToCallSiteMethod(type);
269 }
270 }
271 // Tracing logic:
272 static MemberName linkCallSiteTracing(Class<?> caller,
273 MethodHandle bootstrapMethod,
274 String name, MethodType type,
275 Object staticArguments,
276 Object[] appendixResult) {
277 Object bsmReference = bootstrapMethod.internalMemberName();
278 if (bsmReference == null) bsmReference = bootstrapMethod;
279 String staticArglist = staticArglistForTrace(staticArguments);
280 System.out.println("linkCallSite "+caller.getName()+" "+
281 bsmReference+" "+
282 name+type+"/"+staticArglist);
283 try {
284 MemberName res = linkCallSiteImpl(caller, bootstrapMethod, name, type,
285 staticArguments, appendixResult);
286 System.out.println("linkCallSite => "+res+" + "+appendixResult[0]);
287 return res;
288 } catch (Throwable ex) {
289 ex.printStackTrace(); // print now in case exception is swallowed
290 System.out.println("linkCallSite => throw "+ex);
291 throw ex;
292 }
293 }
294
295 // this implements the upcall from the JVM, MethodHandleNatives.linkDynamicConstant:
296 static Object linkDynamicConstant(Object callerObj,
297 int indexInCP,
298 Object bootstrapMethodObj,
299 Object nameObj, Object typeObj,
300 Object staticArguments) {
301 MethodHandle bootstrapMethod = (MethodHandle)bootstrapMethodObj;
302 Class<?> caller = (Class<?>)callerObj;
303 String name = nameObj.toString().intern();
304 Class<?> type = (Class<?>)typeObj;
305 if (!TRACE_METHOD_LINKAGE)
306 return linkDynamicConstantImpl(caller, bootstrapMethod, name, type, staticArguments);
307 return linkDynamicConstantTracing(caller, bootstrapMethod, name, type, staticArguments);
308 }
309
310 static Object linkDynamicConstantImpl(Class<?> caller,
311 MethodHandle bootstrapMethod,
312 String name, Class<?> type,
313 Object staticArguments) {
314 return ConstantBootstraps.makeConstant(bootstrapMethod, name, type, staticArguments, caller);
315 }
316
317 private static String staticArglistForTrace(Object staticArguments) {
318 if (staticArguments instanceof Object[])
319 return "BSA="+java.util.Arrays.asList((Object[]) staticArguments);
320 if (staticArguments instanceof int[])
321 return "BSA@"+java.util.Arrays.toString((int[]) staticArguments);
322 if (staticArguments == null)
323 return "BSA0=null";
324 return "BSA1="+staticArguments;
325 }
326
327 // Tracing logic:
328 static Object linkDynamicConstantTracing(Class<?> caller,
329 MethodHandle bootstrapMethod,
330 String name, Class<?> type,
331 Object staticArguments) {
332 Object bsmReference = bootstrapMethod.internalMemberName();
333 if (bsmReference == null) bsmReference = bootstrapMethod;
334 String staticArglist = staticArglistForTrace(staticArguments);
335 System.out.println("linkDynamicConstant "+caller.getName()+" "+
336 bsmReference+" "+
337 name+type+"/"+staticArglist);
338 try {
339 Object res = linkDynamicConstantImpl(caller, bootstrapMethod, name, type, staticArguments);
340 System.out.println("linkDynamicConstantImpl => "+res);
341 return res;
342 } catch (Throwable ex) {
343 ex.printStackTrace(); // print now in case exception is swallowed
344 System.out.println("linkDynamicConstant => throw "+ex);
345 throw ex;
346 }
347 }
348
349 /** The JVM is requesting pull-mode bootstrap when it provides
350 * a tuple of the form int[]{ argc, vmindex }.
351 * The BSM is expected to call back to the JVM using the caller
352 * class and vmindex to resolve the static arguments.
353 */
354 static boolean staticArgumentsPulled(Object staticArguments) {
355 return staticArguments instanceof int[];
356 }
357
358 /** A BSM runs in pull-mode if and only if its sole arguments
359 * are (Lookup, BootstrapCallInfo), or can be converted pairwise
360 * to those types, and it is not of variable arity.
361 * Excluding error cases, we can just test that the arity is a constant 2.
362 *
363 * NOTE: This method currently returns false, since pulling is not currently
364 * exposed to a BSM. When pull mode is supported the method block will be
365 * replaced with currently commented out code.
366 */
367 static boolean isPullModeBSM(MethodHandle bsm) {
368 return false;
369 // return bsm.type().parameterCount() == 2 && !bsm.isVarargsCollector();
370 }
371
372 /**
373 * The JVM wants a pointer to a MethodType. Oblige it by finding or creating one.
374 */
375 static MethodType findMethodHandleType(Class<?> rtype, Class<?>[] ptypes) {
376 return MethodType.makeImpl(rtype, ptypes, true);
377 }
378
379 /**
380 * The JVM wants to link a call site that requires a dynamic type check.
381 * Name is a type-checking invoker, invokeExact or invoke.
382 * Return a JVM method (MemberName) to handle the invoking.
383 * The method assumes the following arguments on the stack:
384 * 0: the method handle being invoked
385 * 1-N: the arguments to the method handle invocation
386 * N+1: an optional, implicitly added argument (typically the given MethodType)
387 * <p>
388 * The nominal method at such a call site is an instance of
389 * a signature-polymorphic method (see @PolymorphicSignature).
390 * Such method instances are user-visible entities which are
391 * "split" from the generic placeholder method in {@code MethodHandle}.
392 * (Note that the placeholder method is not identical with any of
393 * its instances. If invoked reflectively, is guaranteed to throw an
394 * {@code UnsupportedOperationException}.)
395 * If the signature-polymorphic method instance is ever reified,
396 * it appears as a "copy" of the original placeholder
397 * (a native final member of {@code MethodHandle}) except
398 * that its type descriptor has shape required by the instance,
399 * and the method instance is <em>not</em> varargs.
400 * The method instance is also marked synthetic, since the
401 * method (by definition) does not appear in Java source code.
402 * <p>
403 * The JVM is allowed to reify this method as instance metadata.
404 * For example, {@code invokeBasic} is always reified.
405 * But the JVM may instead call {@code linkMethod}.
406 * If the result is an * ordered pair of a {@code (method, appendix)},
407 * the method gets all the arguments (0..N inclusive)
408 * plus the appendix (N+1), and uses the appendix to complete the call.
409 * In this way, one reusable method (called a "linker method")
410 * can perform the function of any number of polymorphic instance
411 * methods.
412 * <p>
413 * Linker methods are allowed to be weakly typed, with any or
414 * all references rewritten to {@code Object} and any primitives
415 * (except {@code long}/{@code float}/{@code double})
416 * rewritten to {@code int}.
417 * A linker method is trusted to return a strongly typed result,
418 * according to the specific method type descriptor of the
419 * signature-polymorphic instance it is emulating.
420 * This can involve (as necessary) a dynamic check using
421 * data extracted from the appendix argument.
422 * <p>
423 * The JVM does not inspect the appendix, other than to pass
424 * it verbatim to the linker method at every call.
425 * This means that the JDK runtime has wide latitude
426 * for choosing the shape of each linker method and its
427 * corresponding appendix.
428 * Linker methods should be generated from {@code LambdaForm}s
429 * so that they do not become visible on stack traces.
430 * <p>
431 * The {@code linkMethod} call is free to omit the appendix
432 * (returning null) and instead emulate the required function
433 * completely in the linker method.
434 * As a corner case, if N==255, no appendix is possible.
435 * In this case, the method returned must be custom-generated to
436 * to perform any needed type checking.
437 * <p>
438 * If the JVM does not reify a method at a call site, but instead
439 * calls {@code linkMethod}, the corresponding call represented
440 * in the bytecodes may mention a valid method which is not
441 * representable with a {@code MemberName}.
442 * Therefore, use cases for {@code linkMethod} tend to correspond to
443 * special cases in reflective code such as {@code findVirtual}
444 * or {@code revealDirect}.
445 */
446 static MemberName linkMethod(Class<?> callerClass, int refKind,
447 Class<?> defc, String name, Object type,
448 Object[] appendixResult) {
449 if (!TRACE_METHOD_LINKAGE)
450 return linkMethodImpl(callerClass, refKind, defc, name, type, appendixResult);
451 return linkMethodTracing(callerClass, refKind, defc, name, type, appendixResult);
452 }
453 static MemberName linkMethodImpl(Class<?> callerClass, int refKind,
454 Class<?> defc, String name, Object type,
455 Object[] appendixResult) {
456 try {
457 if (refKind == REF_invokeVirtual) {
458 if (defc == MethodHandle.class) {
459 return Invokers.methodHandleInvokeLinkerMethod(
460 name, fixMethodType(callerClass, type), appendixResult);
461 } else if (defc == VarHandle.class) {
462 return varHandleOperationLinkerMethod(
463 name, fixMethodType(callerClass, type), appendixResult);
464 }
465 }
466 } catch (Error e) {
467 // Pass through an Error, including say StackOverflowError or
468 // OutOfMemoryError
469 throw e;
470 } catch (Throwable ex) {
471 // Wrap anything else in LinkageError
472 throw new LinkageError(ex.getMessage(), ex);
473 }
474 throw new LinkageError("no such method "+defc.getName()+"."+name+type);
475 }
476 private static MethodType fixMethodType(Class<?> callerClass, Object type) {
477 if (type instanceof MethodType)
478 return (MethodType) type;
479 else
480 return MethodType.fromDescriptor((String)type, callerClass.getClassLoader());
481 }
482 // Tracing logic:
483 static MemberName linkMethodTracing(Class<?> callerClass, int refKind,
484 Class<?> defc, String name, Object type,
485 Object[] appendixResult) {
486 System.out.println("linkMethod "+defc.getName()+"."+
487 name+type+"/"+Integer.toHexString(refKind));
488 try {
489 MemberName res = linkMethodImpl(callerClass, refKind, defc, name, type, appendixResult);
490 System.out.println("linkMethod => "+res+" + "+appendixResult[0]);
491 return res;
492 } catch (Throwable ex) {
493 System.out.println("linkMethod => throw "+ex);
494 throw ex;
495 }
496 }
497
498 /**
499 * Obtain the method to link to the VarHandle operation.
500 * This method is located here and not in Invokers to avoid
501 * intializing that and other classes early on in VM bootup.
502 */
503 private static MemberName varHandleOperationLinkerMethod(String name,
504 MethodType mtype,
505 Object[] appendixResult) {
506 // Get the signature method type
507 final MethodType sigType = mtype.basicType();
508
509 // Get the access kind from the method name
510 VarHandle.AccessMode ak;
511 try {
512 ak = VarHandle.AccessMode.valueFromMethodName(name);
513 } catch (IllegalArgumentException e) {
514 throw MethodHandleStatics.newInternalError(e);
515 }
516
517 // Create the appendix descriptor constant
518 VarHandle.AccessDescriptor ad = new VarHandle.AccessDescriptor(mtype, ak.at.ordinal(), ak.ordinal());
519 appendixResult[0] = ad;
520
521 if (MethodHandleStatics.VAR_HANDLE_GUARDS) {
522 // If not polymorphic in the return type, such as the compareAndSet
523 // methods that return boolean
524 Class<?> guardReturnType = sigType.returnType();
525 if (ak.at.isMonomorphicInReturnType) {
526 if (ak.at.returnType != mtype.returnType()) {
527 // The caller contains a different return type than that
528 // defined by the method
529 throw newNoSuchMethodErrorOnVarHandle(name, mtype);
530 }
531 // Adjust the return type of the signature method type
532 guardReturnType = ak.at.returnType;
533 }
534
535 // Get the guard method type for linking
536 final Class<?>[] guardParams = new Class<?>[sigType.parameterCount() + 2];
537 // VarHandle at start
538 guardParams[0] = VarHandle.class;
539 for (int i = 0; i < sigType.parameterCount(); i++) {
540 guardParams[i + 1] = sigType.parameterType(i);
541 }
542 // Access descriptor at end
543 guardParams[guardParams.length - 1] = VarHandle.AccessDescriptor.class;
544 MethodType guardType = MethodType.makeImpl(guardReturnType, guardParams, true);
545
546 MemberName linker = new MemberName(
547 VarHandleGuards.class, getVarHandleGuardMethodName(guardType),
548 guardType, REF_invokeStatic);
549
550 linker = MemberName.getFactory().resolveOrNull(REF_invokeStatic, linker,
551 VarHandleGuards.class);
552 if (linker != null) {
553 return linker;
554 }
555 // Fall back to lambda form linkage if guard method is not available
556 // TODO Optionally log fallback ?
557 }
558 return Invokers.varHandleInvokeLinkerMethod(ak, mtype);
559 }
560 static String getVarHandleGuardMethodName(MethodType guardType) {
561 String prefix = "guard_";
562 StringBuilder sb = new StringBuilder(prefix.length() + guardType.parameterCount());
563
564 sb.append(prefix);
565 for (int i = 1; i < guardType.parameterCount() - 1; i++) {
566 Class<?> pt = guardType.parameterType(i);
567 sb.append(getCharType(pt));
568 }
569 sb.append('_').append(getCharType(guardType.returnType()));
570 return sb.toString();
571 }
572 static char getCharType(Class<?> pt) {
573 return Wrapper.forBasicType(pt).basicTypeChar();
574 }
575 static NoSuchMethodError newNoSuchMethodErrorOnVarHandle(String name, MethodType mtype) {
576 return new NoSuchMethodError("VarHandle." + name + mtype);
577 }
578
579 /**
580 * The JVM is resolving a CONSTANT_MethodHandle CP entry. And it wants our help.
581 * It will make an up-call to this method. (Do not change the name or signature.)
582 * The type argument is a Class for field requests and a MethodType for non-fields.
583 * <p>
584 * Recent versions of the JVM may also pass a resolved MemberName for the type.
585 * In that case, the name is ignored and may be null.
586 */
587 static MethodHandle linkMethodHandleConstant(Class<?> callerClass, int refKind,
588 Class<?> defc, String name, Object type) {
589 try {
590 Lookup lookup = IMPL_LOOKUP.in(callerClass);
591 assert(refKindIsValid(refKind));
592 return lookup.linkMethodHandleConstant((byte) refKind, defc, name, type);
593 } catch (ReflectiveOperationException ex) {
594 throw mapLookupExceptionToError(ex);
595 }
596 }
597
598 /**
599 * Map a reflective exception to a linkage error.
600 */
601 static LinkageError mapLookupExceptionToError(ReflectiveOperationException ex) {
602 LinkageError err;
603 if (ex instanceof IllegalAccessException) {
604 Throwable cause = ex.getCause();
605 if (cause instanceof AbstractMethodError) {
606 return (AbstractMethodError) cause;
607 } else {
608 err = new IllegalAccessError(ex.getMessage());
609 }
610 } else if (ex instanceof NoSuchMethodException) {
611 err = new NoSuchMethodError(ex.getMessage());
612 } else if (ex instanceof NoSuchFieldException) {
613 err = new NoSuchFieldError(ex.getMessage());
614 } else {
615 err = new IncompatibleClassChangeError();
616 }
617 return initCauseFrom(err, ex);
618 }
619
620 /**
621 * Use best possible cause for err.initCause(), substituting the
622 * cause for err itself if the cause has the same (or better) type.
623 */
624 static <E extends Error> E initCauseFrom(E err, Exception ex) {
625 Throwable th = ex.getCause();
626 @SuppressWarnings("unchecked")
627 final Class<E> Eclass = (Class<E>) err.getClass();
628 if (Eclass.isInstance(th))
629 return Eclass.cast(th);
630 err.initCause(th == null ? ex : th);
631 return err;
632 }
633
634 /**
635 * Is this method a caller-sensitive method?
636 * I.e., does it call Reflection.getCallerClass or a similar method
637 * to ask about the identity of its caller?
638 */
639 static boolean isCallerSensitive(MemberName mem) {
640 if (!mem.isInvocable()) return false; // fields are not caller sensitive
641
642 return mem.isCallerSensitive() || canBeCalledVirtual(mem);
643 }
644
645 static boolean canBeCalledVirtual(MemberName mem) {
646 assert(mem.isInvocable());
647 switch (mem.getName()) {
648 case "getContextClassLoader":
649 return canBeCalledVirtual(mem, java.lang.Thread.class);
650 }
651 return false;
652 }
653
654 static boolean canBeCalledVirtual(MemberName symbolicRef, Class<?> definingClass) {
655 Class<?> symbolicRefClass = symbolicRef.getDeclaringClass();
656 if (symbolicRefClass == definingClass) return true;
657 if (symbolicRef.isStatic() || symbolicRef.isPrivate()) return false;
658 return (definingClass.isAssignableFrom(symbolicRefClass) || // Msym overrides Mdef
659 symbolicRefClass.isInterface()); // Mdef implements Msym
660 }
661 }