1 /*
2 * Copyright (c) 2003, 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.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "classfile/metadataOnStackMark.hpp"
27 #include "classfile/systemDictionary.hpp"
28 #include "classfile/verifier.hpp"
29 #include "code/codeCache.hpp"
30 #include "compiler/compileBroker.hpp"
31 #include "interpreter/oopMapCache.hpp"
32 #include "interpreter/rewriter.hpp"
33 #include "memory/gcLocker.hpp"
34 #include "memory/metadataFactory.hpp"
35 #include "memory/metaspaceShared.hpp"
36 #include "memory/universe.inline.hpp"
37 #include "oops/fieldStreams.hpp"
38 #include "oops/klassVtable.hpp"
39 #include "prims/jvmtiImpl.hpp"
40 #include "prims/jvmtiRedefineClasses.hpp"
41 #include "prims/methodComparator.hpp"
42 #include "runtime/deoptimization.hpp"
43 #include "runtime/relocator.hpp"
44 #include "utilities/bitMap.inline.hpp"
45
46
47 Array<Method*>* VM_RedefineClasses::_old_methods = NULL;
48 Array<Method*>* VM_RedefineClasses::_new_methods = NULL;
49 Method** VM_RedefineClasses::_matching_old_methods = NULL;
50 Method** VM_RedefineClasses::_matching_new_methods = NULL;
51 Method** VM_RedefineClasses::_deleted_methods = NULL;
52 Method** VM_RedefineClasses::_added_methods = NULL;
53 int VM_RedefineClasses::_matching_methods_length = 0;
54 int VM_RedefineClasses::_deleted_methods_length = 0;
55 int VM_RedefineClasses::_added_methods_length = 0;
56 Klass* VM_RedefineClasses::_the_class_oop = NULL;
57
58
59 VM_RedefineClasses::VM_RedefineClasses(jint class_count,
60 const jvmtiClassDefinition *class_defs,
61 JvmtiClassLoadKind class_load_kind) {
62 _class_count = class_count;
63 _class_defs = class_defs;
64 _class_load_kind = class_load_kind;
65 _res = JVMTI_ERROR_NONE;
66 }
67
68 bool VM_RedefineClasses::doit_prologue() {
69 if (_class_count == 0) {
70 _res = JVMTI_ERROR_NONE;
71 return false;
72 }
73 if (_class_defs == NULL) {
74 _res = JVMTI_ERROR_NULL_POINTER;
75 return false;
76 }
77 for (int i = 0; i < _class_count; i++) {
78 if (_class_defs[i].klass == NULL) {
79 _res = JVMTI_ERROR_INVALID_CLASS;
80 return false;
81 }
82 if (_class_defs[i].class_byte_count == 0) {
83 _res = JVMTI_ERROR_INVALID_CLASS_FORMAT;
84 return false;
85 }
86 if (_class_defs[i].class_bytes == NULL) {
87 _res = JVMTI_ERROR_NULL_POINTER;
88 return false;
89 }
90 }
91
92 // Start timer after all the sanity checks; not quite accurate, but
93 // better than adding a bunch of stop() calls.
94 RC_TIMER_START(_timer_vm_op_prologue);
95
96 // We first load new class versions in the prologue, because somewhere down the
97 // call chain it is required that the current thread is a Java thread.
98 _res = load_new_class_versions(Thread::current());
99 if (_res != JVMTI_ERROR_NONE) {
100 // free any successfully created classes, since none are redefined
101 for (int i = 0; i < _class_count; i++) {
102 if (_scratch_classes[i] != NULL) {
103 ClassLoaderData* cld = _scratch_classes[i]->class_loader_data();
104 // Free the memory for this class at class unloading time. Not before
105 // because CMS might think this is still live.
106 cld->add_to_deallocate_list((InstanceKlass*)_scratch_classes[i]);
107 }
108 }
109 // Free os::malloc allocated memory in load_new_class_version.
110 os::free(_scratch_classes);
111 RC_TIMER_STOP(_timer_vm_op_prologue);
112 return false;
113 }
114
115 RC_TIMER_STOP(_timer_vm_op_prologue);
116 return true;
117 }
118
119 void VM_RedefineClasses::doit() {
120 Thread *thread = Thread::current();
121
122 if (UseSharedSpaces) {
123 // Sharing is enabled so we remap the shared readonly space to
124 // shared readwrite, private just in case we need to redefine
125 // a shared class. We do the remap during the doit() phase of
126 // the safepoint to be safer.
127 if (!MetaspaceShared::remap_shared_readonly_as_readwrite()) {
128 RC_TRACE_WITH_THREAD(0x00000001, thread,
129 ("failed to remap shared readonly space to readwrite, private"));
130 _res = JVMTI_ERROR_INTERNAL;
131 return;
132 }
133 }
134
135 // Mark methods seen on stack and everywhere else so old methods are not
136 // cleaned up if they're on the stack.
137 MetadataOnStackMark md_on_stack;
138 HandleMark hm(thread); // make sure any handles created are deleted
139 // before the stack walk again.
140
141 for (int i = 0; i < _class_count; i++) {
142 redefine_single_class(_class_defs[i].klass, _scratch_classes[i], thread);
143 ClassLoaderData* cld = _scratch_classes[i]->class_loader_data();
144 // Free the memory for this class at class unloading time. Not before
145 // because CMS might think this is still live.
146 cld->add_to_deallocate_list((InstanceKlass*)_scratch_classes[i]);
147 _scratch_classes[i] = NULL;
148 }
149
150 // Disable any dependent concurrent compilations
151 SystemDictionary::notice_modification();
152
153 // Set flag indicating that some invariants are no longer true.
154 // See jvmtiExport.hpp for detailed explanation.
155 JvmtiExport::set_has_redefined_a_class();
156
157 // check_class() is optionally called for product bits, but is
158 // always called for non-product bits.
159 #ifdef PRODUCT
160 if (RC_TRACE_ENABLED(0x00004000)) {
161 #endif
162 RC_TRACE_WITH_THREAD(0x00004000, thread, ("calling check_class"));
163 SystemDictionary::classes_do(check_class, thread);
164 #ifdef PRODUCT
165 }
166 #endif
167 }
168
169 void VM_RedefineClasses::doit_epilogue() {
170 // Free os::malloc allocated memory.
171 os::free(_scratch_classes);
172
173 if (RC_TRACE_ENABLED(0x00000004)) {
174 // Used to have separate timers for "doit" and "all", but the timer
175 // overhead skewed the measurements.
176 jlong doit_time = _timer_rsc_phase1.milliseconds() +
177 _timer_rsc_phase2.milliseconds();
178 jlong all_time = _timer_vm_op_prologue.milliseconds() + doit_time;
179
180 RC_TRACE(0x00000004, ("vm_op: all=" UINT64_FORMAT
181 " prologue=" UINT64_FORMAT " doit=" UINT64_FORMAT, all_time,
182 _timer_vm_op_prologue.milliseconds(), doit_time));
183 RC_TRACE(0x00000004,
184 ("redefine_single_class: phase1=" UINT64_FORMAT " phase2=" UINT64_FORMAT,
185 _timer_rsc_phase1.milliseconds(), _timer_rsc_phase2.milliseconds()));
186 }
187 }
188
189 bool VM_RedefineClasses::is_modifiable_class(oop klass_mirror) {
190 // classes for primitives cannot be redefined
191 if (java_lang_Class::is_primitive(klass_mirror)) {
192 return false;
193 }
194 Klass* the_class_oop = java_lang_Class::as_Klass(klass_mirror);
195 // classes for arrays cannot be redefined
196 if (the_class_oop == NULL || !the_class_oop->oop_is_instance()) {
197 return false;
198 }
199 return true;
200 }
201
202 // Append the current entry at scratch_i in scratch_cp to *merge_cp_p
203 // where the end of *merge_cp_p is specified by *merge_cp_length_p. For
204 // direct CP entries, there is just the current entry to append. For
205 // indirect and double-indirect CP entries, there are zero or more
206 // referenced CP entries along with the current entry to append.
207 // Indirect and double-indirect CP entries are handled by recursive
208 // calls to append_entry() as needed. The referenced CP entries are
209 // always appended to *merge_cp_p before the referee CP entry. These
210 // referenced CP entries may already exist in *merge_cp_p in which case
211 // there is nothing extra to append and only the current entry is
212 // appended.
213 void VM_RedefineClasses::append_entry(constantPoolHandle scratch_cp,
214 int scratch_i, constantPoolHandle *merge_cp_p, int *merge_cp_length_p,
215 TRAPS) {
216
217 // append is different depending on entry tag type
218 switch (scratch_cp->tag_at(scratch_i).value()) {
219
220 // The old verifier is implemented outside the VM. It loads classes,
221 // but does not resolve constant pool entries directly so we never
222 // see Class entries here with the old verifier. Similarly the old
223 // verifier does not like Class entries in the input constant pool.
224 // The split-verifier is implemented in the VM so it can optionally
225 // and directly resolve constant pool entries to load classes. The
226 // split-verifier can accept either Class entries or UnresolvedClass
227 // entries in the input constant pool. We revert the appended copy
228 // back to UnresolvedClass so that either verifier will be happy
229 // with the constant pool entry.
230 case JVM_CONSTANT_Class:
231 {
232 // revert the copy to JVM_CONSTANT_UnresolvedClass
233 (*merge_cp_p)->unresolved_klass_at_put(*merge_cp_length_p,
234 scratch_cp->klass_name_at(scratch_i));
235
236 if (scratch_i != *merge_cp_length_p) {
237 // The new entry in *merge_cp_p is at a different index than
238 // the new entry in scratch_cp so we need to map the index values.
239 map_index(scratch_cp, scratch_i, *merge_cp_length_p);
240 }
241 (*merge_cp_length_p)++;
242 } break;
243
244 // these are direct CP entries so they can be directly appended,
245 // but double and long take two constant pool entries
246 case JVM_CONSTANT_Double: // fall through
247 case JVM_CONSTANT_Long:
248 {
249 ConstantPool::copy_entry_to(scratch_cp, scratch_i, *merge_cp_p, *merge_cp_length_p,
250 THREAD);
251
252 if (scratch_i != *merge_cp_length_p) {
253 // The new entry in *merge_cp_p is at a different index than
254 // the new entry in scratch_cp so we need to map the index values.
255 map_index(scratch_cp, scratch_i, *merge_cp_length_p);
256 }
257 (*merge_cp_length_p) += 2;
258 } break;
259
260 // these are direct CP entries so they can be directly appended
261 case JVM_CONSTANT_Float: // fall through
262 case JVM_CONSTANT_Integer: // fall through
263 case JVM_CONSTANT_Utf8: // fall through
264
265 // This was an indirect CP entry, but it has been changed into
266 // Symbol*s so this entry can be directly appended.
267 case JVM_CONSTANT_String: // fall through
268
269 // These were indirect CP entries, but they have been changed into
270 // Symbol*s so these entries can be directly appended.
271 case JVM_CONSTANT_UnresolvedClass: // fall through
272 {
273 ConstantPool::copy_entry_to(scratch_cp, scratch_i, *merge_cp_p, *merge_cp_length_p,
274 THREAD);
275
276 if (scratch_i != *merge_cp_length_p) {
277 // The new entry in *merge_cp_p is at a different index than
278 // the new entry in scratch_cp so we need to map the index values.
279 map_index(scratch_cp, scratch_i, *merge_cp_length_p);
280 }
281 (*merge_cp_length_p)++;
282 } break;
283
284 // this is an indirect CP entry so it needs special handling
285 case JVM_CONSTANT_NameAndType:
286 {
287 int name_ref_i = scratch_cp->name_ref_index_at(scratch_i);
288 int new_name_ref_i = 0;
289 bool match = (name_ref_i < *merge_cp_length_p) &&
290 scratch_cp->compare_entry_to(name_ref_i, *merge_cp_p, name_ref_i,
291 THREAD);
292 if (!match) {
293 // forward reference in *merge_cp_p or not a direct match
294
295 int found_i = scratch_cp->find_matching_entry(name_ref_i, *merge_cp_p,
296 THREAD);
297 if (found_i != 0) {
298 guarantee(found_i != name_ref_i,
299 "compare_entry_to() and find_matching_entry() do not agree");
300
301 // Found a matching entry somewhere else in *merge_cp_p so
302 // just need a mapping entry.
303 new_name_ref_i = found_i;
304 map_index(scratch_cp, name_ref_i, found_i);
305 } else {
306 // no match found so we have to append this entry to *merge_cp_p
307 append_entry(scratch_cp, name_ref_i, merge_cp_p, merge_cp_length_p,
308 THREAD);
309 // The above call to append_entry() can only append one entry
310 // so the post call query of *merge_cp_length_p is only for
311 // the sake of consistency.
312 new_name_ref_i = *merge_cp_length_p - 1;
313 }
314 }
315
316 int signature_ref_i = scratch_cp->signature_ref_index_at(scratch_i);
317 int new_signature_ref_i = 0;
318 match = (signature_ref_i < *merge_cp_length_p) &&
319 scratch_cp->compare_entry_to(signature_ref_i, *merge_cp_p,
320 signature_ref_i, THREAD);
321 if (!match) {
322 // forward reference in *merge_cp_p or not a direct match
323
324 int found_i = scratch_cp->find_matching_entry(signature_ref_i,
325 *merge_cp_p, THREAD);
326 if (found_i != 0) {
327 guarantee(found_i != signature_ref_i,
328 "compare_entry_to() and find_matching_entry() do not agree");
329
330 // Found a matching entry somewhere else in *merge_cp_p so
331 // just need a mapping entry.
332 new_signature_ref_i = found_i;
333 map_index(scratch_cp, signature_ref_i, found_i);
334 } else {
335 // no match found so we have to append this entry to *merge_cp_p
336 append_entry(scratch_cp, signature_ref_i, merge_cp_p,
337 merge_cp_length_p, THREAD);
338 // The above call to append_entry() can only append one entry
339 // so the post call query of *merge_cp_length_p is only for
340 // the sake of consistency.
341 new_signature_ref_i = *merge_cp_length_p - 1;
342 }
343 }
344
345 // If the referenced entries already exist in *merge_cp_p, then
346 // both new_name_ref_i and new_signature_ref_i will both be 0.
347 // In that case, all we are appending is the current entry.
348 if (new_name_ref_i == 0) {
349 new_name_ref_i = name_ref_i;
350 } else {
351 RC_TRACE(0x00080000,
352 ("NameAndType entry@%d name_ref_index change: %d to %d",
353 *merge_cp_length_p, name_ref_i, new_name_ref_i));
354 }
355 if (new_signature_ref_i == 0) {
356 new_signature_ref_i = signature_ref_i;
357 } else {
358 RC_TRACE(0x00080000,
359 ("NameAndType entry@%d signature_ref_index change: %d to %d",
360 *merge_cp_length_p, signature_ref_i, new_signature_ref_i));
361 }
362
363 (*merge_cp_p)->name_and_type_at_put(*merge_cp_length_p,
364 new_name_ref_i, new_signature_ref_i);
365 if (scratch_i != *merge_cp_length_p) {
366 // The new entry in *merge_cp_p is at a different index than
367 // the new entry in scratch_cp so we need to map the index values.
368 map_index(scratch_cp, scratch_i, *merge_cp_length_p);
369 }
370 (*merge_cp_length_p)++;
371 } break;
372
373 // this is a double-indirect CP entry so it needs special handling
374 case JVM_CONSTANT_Fieldref: // fall through
375 case JVM_CONSTANT_InterfaceMethodref: // fall through
376 case JVM_CONSTANT_Methodref:
377 {
378 int klass_ref_i = scratch_cp->uncached_klass_ref_index_at(scratch_i);
379 int new_klass_ref_i = 0;
380 bool match = (klass_ref_i < *merge_cp_length_p) &&
381 scratch_cp->compare_entry_to(klass_ref_i, *merge_cp_p, klass_ref_i,
382 THREAD);
383 if (!match) {
384 // forward reference in *merge_cp_p or not a direct match
385
386 int found_i = scratch_cp->find_matching_entry(klass_ref_i, *merge_cp_p,
387 THREAD);
388 if (found_i != 0) {
389 guarantee(found_i != klass_ref_i,
390 "compare_entry_to() and find_matching_entry() do not agree");
391
392 // Found a matching entry somewhere else in *merge_cp_p so
393 // just need a mapping entry.
394 new_klass_ref_i = found_i;
395 map_index(scratch_cp, klass_ref_i, found_i);
396 } else {
397 // no match found so we have to append this entry to *merge_cp_p
398 append_entry(scratch_cp, klass_ref_i, merge_cp_p, merge_cp_length_p,
399 THREAD);
400 // The above call to append_entry() can only append one entry
401 // so the post call query of *merge_cp_length_p is only for
402 // the sake of consistency. Without the optimization where we
403 // use JVM_CONSTANT_UnresolvedClass, then up to two entries
404 // could be appended.
405 new_klass_ref_i = *merge_cp_length_p - 1;
406 }
407 }
408
409 int name_and_type_ref_i =
410 scratch_cp->uncached_name_and_type_ref_index_at(scratch_i);
411 int new_name_and_type_ref_i = 0;
412 match = (name_and_type_ref_i < *merge_cp_length_p) &&
413 scratch_cp->compare_entry_to(name_and_type_ref_i, *merge_cp_p,
414 name_and_type_ref_i, THREAD);
415 if (!match) {
416 // forward reference in *merge_cp_p or not a direct match
417
418 int found_i = scratch_cp->find_matching_entry(name_and_type_ref_i,
419 *merge_cp_p, THREAD);
420 if (found_i != 0) {
421 guarantee(found_i != name_and_type_ref_i,
422 "compare_entry_to() and find_matching_entry() do not agree");
423
424 // Found a matching entry somewhere else in *merge_cp_p so
425 // just need a mapping entry.
426 new_name_and_type_ref_i = found_i;
427 map_index(scratch_cp, name_and_type_ref_i, found_i);
428 } else {
429 // no match found so we have to append this entry to *merge_cp_p
430 append_entry(scratch_cp, name_and_type_ref_i, merge_cp_p,
431 merge_cp_length_p, THREAD);
432 // The above call to append_entry() can append more than
433 // one entry so the post call query of *merge_cp_length_p
434 // is required in order to get the right index for the
435 // JVM_CONSTANT_NameAndType entry.
436 new_name_and_type_ref_i = *merge_cp_length_p - 1;
437 }
438 }
439
440 // If the referenced entries already exist in *merge_cp_p, then
441 // both new_klass_ref_i and new_name_and_type_ref_i will both be
442 // 0. In that case, all we are appending is the current entry.
443 if (new_klass_ref_i == 0) {
444 new_klass_ref_i = klass_ref_i;
445 }
446 if (new_name_and_type_ref_i == 0) {
447 new_name_and_type_ref_i = name_and_type_ref_i;
448 }
449
450 const char *entry_name;
451 switch (scratch_cp->tag_at(scratch_i).value()) {
452 case JVM_CONSTANT_Fieldref:
453 entry_name = "Fieldref";
454 (*merge_cp_p)->field_at_put(*merge_cp_length_p, new_klass_ref_i,
455 new_name_and_type_ref_i);
456 break;
457 case JVM_CONSTANT_InterfaceMethodref:
458 entry_name = "IFMethodref";
459 (*merge_cp_p)->interface_method_at_put(*merge_cp_length_p,
460 new_klass_ref_i, new_name_and_type_ref_i);
461 break;
462 case JVM_CONSTANT_Methodref:
463 entry_name = "Methodref";
464 (*merge_cp_p)->method_at_put(*merge_cp_length_p, new_klass_ref_i,
465 new_name_and_type_ref_i);
466 break;
467 default:
468 guarantee(false, "bad switch");
469 break;
470 }
471
472 if (klass_ref_i != new_klass_ref_i) {
473 RC_TRACE(0x00080000, ("%s entry@%d class_index changed: %d to %d",
474 entry_name, *merge_cp_length_p, klass_ref_i, new_klass_ref_i));
475 }
476 if (name_and_type_ref_i != new_name_and_type_ref_i) {
477 RC_TRACE(0x00080000,
478 ("%s entry@%d name_and_type_index changed: %d to %d",
479 entry_name, *merge_cp_length_p, name_and_type_ref_i,
480 new_name_and_type_ref_i));
481 }
482
483 if (scratch_i != *merge_cp_length_p) {
484 // The new entry in *merge_cp_p is at a different index than
485 // the new entry in scratch_cp so we need to map the index values.
486 map_index(scratch_cp, scratch_i, *merge_cp_length_p);
487 }
488 (*merge_cp_length_p)++;
489 } break;
490
491 // At this stage, Class or UnresolvedClass could be here, but not
492 // ClassIndex
493 case JVM_CONSTANT_ClassIndex: // fall through
494
495 // Invalid is used as the tag for the second constant pool entry
496 // occupied by JVM_CONSTANT_Double or JVM_CONSTANT_Long. It should
497 // not be seen by itself.
498 case JVM_CONSTANT_Invalid: // fall through
499
500 // At this stage, String could be here, but not StringIndex
501 case JVM_CONSTANT_StringIndex: // fall through
502
503 // At this stage JVM_CONSTANT_UnresolvedClassInError should not be
504 // here
505 case JVM_CONSTANT_UnresolvedClassInError: // fall through
506
507 default:
508 {
509 // leave a breadcrumb
510 jbyte bad_value = scratch_cp->tag_at(scratch_i).value();
511 ShouldNotReachHere();
512 } break;
513 } // end switch tag value
514 } // end append_entry()
515
516
517 void VM_RedefineClasses::swap_all_method_annotations(int i, int j, instanceKlassHandle scratch_class, TRAPS) {
518 AnnotationArray* save;
519
520 Annotations* sca = scratch_class->annotations();
521 if (sca == NULL) return;
522
523 save = sca->get_method_annotations_of(i);
524 sca->set_method_annotations_of(scratch_class, i, sca->get_method_annotations_of(j), CHECK);
525 sca->set_method_annotations_of(scratch_class, j, save, CHECK);
526
527 save = sca->get_method_parameter_annotations_of(i);
528 sca->set_method_parameter_annotations_of(scratch_class, i, sca->get_method_parameter_annotations_of(j), CHECK);
529 sca->set_method_parameter_annotations_of(scratch_class, j, save, CHECK);
530
531 save = sca->get_method_default_annotations_of(i);
532 sca->set_method_default_annotations_of(scratch_class, i, sca->get_method_default_annotations_of(j), CHECK);
533 sca->set_method_default_annotations_of(scratch_class, j, save, CHECK);
534 }
535
536
537 jvmtiError VM_RedefineClasses::compare_and_normalize_class_versions(
538 instanceKlassHandle the_class,
539 instanceKlassHandle scratch_class) {
540 int i;
541
542 // Check superclasses, or rather their names, since superclasses themselves can be
543 // requested to replace.
544 // Check for NULL superclass first since this might be java.lang.Object
545 if (the_class->super() != scratch_class->super() &&
546 (the_class->super() == NULL || scratch_class->super() == NULL ||
547 the_class->super()->name() !=
548 scratch_class->super()->name())) {
549 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_HIERARCHY_CHANGED;
550 }
551
552 // Check if the number, names and order of directly implemented interfaces are the same.
553 // I think in principle we should just check if the sets of names of directly implemented
554 // interfaces are the same, i.e. the order of declaration (which, however, if changed in the
555 // .java file, also changes in .class file) should not matter. However, comparing sets is
556 // technically a bit more difficult, and, more importantly, I am not sure at present that the
557 // order of interfaces does not matter on the implementation level, i.e. that the VM does not
558 // rely on it somewhere.
559 Array<Klass*>* k_interfaces = the_class->local_interfaces();
560 Array<Klass*>* k_new_interfaces = scratch_class->local_interfaces();
561 int n_intfs = k_interfaces->length();
562 if (n_intfs != k_new_interfaces->length()) {
563 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_HIERARCHY_CHANGED;
564 }
565 for (i = 0; i < n_intfs; i++) {
566 if (k_interfaces->at(i)->name() !=
567 k_new_interfaces->at(i)->name()) {
568 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_HIERARCHY_CHANGED;
569 }
570 }
571
572 // Check whether class is in the error init state.
573 if (the_class->is_in_error_state()) {
574 // TBD #5057930: special error code is needed in 1.6
575 return JVMTI_ERROR_INVALID_CLASS;
576 }
577
578 // Check whether class modifiers are the same.
579 jushort old_flags = (jushort) the_class->access_flags().get_flags();
580 jushort new_flags = (jushort) scratch_class->access_flags().get_flags();
581 if (old_flags != new_flags) {
582 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_CLASS_MODIFIERS_CHANGED;
583 }
584
585 // Check if the number, names, types and order of fields declared in these classes
586 // are the same.
587 JavaFieldStream old_fs(the_class);
588 JavaFieldStream new_fs(scratch_class);
589 for (; !old_fs.done() && !new_fs.done(); old_fs.next(), new_fs.next()) {
590 // access
591 old_flags = old_fs.access_flags().as_short();
592 new_flags = new_fs.access_flags().as_short();
593 if ((old_flags ^ new_flags) & JVM_RECOGNIZED_FIELD_MODIFIERS) {
594 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_SCHEMA_CHANGED;
595 }
596 // offset
597 if (old_fs.offset() != new_fs.offset()) {
598 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_SCHEMA_CHANGED;
599 }
600 // name and signature
601 Symbol* name_sym1 = the_class->constants()->symbol_at(old_fs.name_index());
602 Symbol* sig_sym1 = the_class->constants()->symbol_at(old_fs.signature_index());
603 Symbol* name_sym2 = scratch_class->constants()->symbol_at(new_fs.name_index());
604 Symbol* sig_sym2 = scratch_class->constants()->symbol_at(new_fs.signature_index());
605 if (name_sym1 != name_sym2 || sig_sym1 != sig_sym2) {
606 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_SCHEMA_CHANGED;
607 }
608 }
609
610 // If both streams aren't done then we have a differing number of
611 // fields.
612 if (!old_fs.done() || !new_fs.done()) {
613 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_SCHEMA_CHANGED;
614 }
615
616 // Do a parallel walk through the old and new methods. Detect
617 // cases where they match (exist in both), have been added in
618 // the new methods, or have been deleted (exist only in the
619 // old methods). The class file parser places methods in order
620 // by method name, but does not order overloaded methods by
621 // signature. In order to determine what fate befell the methods,
622 // this code places the overloaded new methods that have matching
623 // old methods in the same order as the old methods and places
624 // new overloaded methods at the end of overloaded methods of
625 // that name. The code for this order normalization is adapted
626 // from the algorithm used in InstanceKlass::find_method().
627 // Since we are swapping out of order entries as we find them,
628 // we only have to search forward through the overloaded methods.
629 // Methods which are added and have the same name as an existing
630 // method (but different signature) will be put at the end of
631 // the methods with that name, and the name mismatch code will
632 // handle them.
633 Array<Method*>* k_old_methods(the_class->methods());
634 Array<Method*>* k_new_methods(scratch_class->methods());
635 int n_old_methods = k_old_methods->length();
636 int n_new_methods = k_new_methods->length();
637 Thread* thread = Thread::current();
638
639 int ni = 0;
640 int oi = 0;
641 while (true) {
642 Method* k_old_method;
643 Method* k_new_method;
644 enum { matched, added, deleted, undetermined } method_was = undetermined;
645
646 if (oi >= n_old_methods) {
647 if (ni >= n_new_methods) {
648 break; // we've looked at everything, done
649 }
650 // New method at the end
651 k_new_method = k_new_methods->at(ni);
652 method_was = added;
653 } else if (ni >= n_new_methods) {
654 // Old method, at the end, is deleted
655 k_old_method = k_old_methods->at(oi);
656 method_was = deleted;
657 } else {
658 // There are more methods in both the old and new lists
659 k_old_method = k_old_methods->at(oi);
660 k_new_method = k_new_methods->at(ni);
661 if (k_old_method->name() != k_new_method->name()) {
662 // Methods are sorted by method name, so a mismatch means added
663 // or deleted
664 if (k_old_method->name()->fast_compare(k_new_method->name()) > 0) {
665 method_was = added;
666 } else {
667 method_was = deleted;
668 }
669 } else if (k_old_method->signature() == k_new_method->signature()) {
670 // Both the name and signature match
671 method_was = matched;
672 } else {
673 // The name matches, but the signature doesn't, which means we have to
674 // search forward through the new overloaded methods.
675 int nj; // outside the loop for post-loop check
676 for (nj = ni + 1; nj < n_new_methods; nj++) {
677 Method* m = k_new_methods->at(nj);
678 if (k_old_method->name() != m->name()) {
679 // reached another method name so no more overloaded methods
680 method_was = deleted;
681 break;
682 }
683 if (k_old_method->signature() == m->signature()) {
684 // found a match so swap the methods
685 k_new_methods->at_put(ni, m);
686 k_new_methods->at_put(nj, k_new_method);
687 k_new_method = m;
688 method_was = matched;
689 break;
690 }
691 }
692
693 if (nj >= n_new_methods) {
694 // reached the end without a match; so method was deleted
695 method_was = deleted;
696 }
697 }
698 }
699
700 switch (method_was) {
701 case matched:
702 // methods match, be sure modifiers do too
703 old_flags = (jushort) k_old_method->access_flags().get_flags();
704 new_flags = (jushort) k_new_method->access_flags().get_flags();
705 if ((old_flags ^ new_flags) & ~(JVM_ACC_NATIVE)) {
706 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_MODIFIERS_CHANGED;
707 }
708 {
709 u2 new_num = k_new_method->method_idnum();
710 u2 old_num = k_old_method->method_idnum();
711 if (new_num != old_num) {
712 Method* idnum_owner = scratch_class->method_with_idnum(old_num);
713 if (idnum_owner != NULL) {
714 // There is already a method assigned this idnum -- switch them
715 idnum_owner->set_method_idnum(new_num);
716 }
717 k_new_method->set_method_idnum(old_num);
718 swap_all_method_annotations(old_num, new_num, scratch_class, thread);
719 if (thread->has_pending_exception()) {
720 return JVMTI_ERROR_OUT_OF_MEMORY;
721 }
722 }
723 }
724 RC_TRACE(0x00008000, ("Method matched: new: %s [%d] == old: %s [%d]",
725 k_new_method->name_and_sig_as_C_string(), ni,
726 k_old_method->name_and_sig_as_C_string(), oi));
727 // advance to next pair of methods
728 ++oi;
729 ++ni;
730 break;
731 case added:
732 // method added, see if it is OK
733 new_flags = (jushort) k_new_method->access_flags().get_flags();
734 if ((new_flags & JVM_ACC_PRIVATE) == 0
735 // hack: private should be treated as final, but alas
736 || (new_flags & (JVM_ACC_FINAL|JVM_ACC_STATIC)) == 0
737 ) {
738 // new methods must be private
739 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_ADDED;
740 }
741 {
742 u2 num = the_class->next_method_idnum();
743 if (num == ConstMethod::UNSET_IDNUM) {
744 // cannot add any more methods
745 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_ADDED;
746 }
747 u2 new_num = k_new_method->method_idnum();
748 Method* idnum_owner = scratch_class->method_with_idnum(num);
749 if (idnum_owner != NULL) {
750 // There is already a method assigned this idnum -- switch them
751 idnum_owner->set_method_idnum(new_num);
752 }
753 k_new_method->set_method_idnum(num);
754 swap_all_method_annotations(new_num, num, scratch_class, thread);
755 if (thread->has_pending_exception()) {
756 return JVMTI_ERROR_OUT_OF_MEMORY;
757 }
758 }
759 RC_TRACE(0x00008000, ("Method added: new: %s [%d]",
760 k_new_method->name_and_sig_as_C_string(), ni));
761 ++ni; // advance to next new method
762 break;
763 case deleted:
764 // method deleted, see if it is OK
765 old_flags = (jushort) k_old_method->access_flags().get_flags();
766 if ((old_flags & JVM_ACC_PRIVATE) == 0
767 // hack: private should be treated as final, but alas
768 || (old_flags & (JVM_ACC_FINAL|JVM_ACC_STATIC)) == 0
769 ) {
770 // deleted methods must be private
771 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_DELETED;
772 }
773 RC_TRACE(0x00008000, ("Method deleted: old: %s [%d]",
774 k_old_method->name_and_sig_as_C_string(), oi));
775 ++oi; // advance to next old method
776 break;
777 default:
778 ShouldNotReachHere();
779 }
780 }
781
782 return JVMTI_ERROR_NONE;
783 }
784
785
786 // Find new constant pool index value for old constant pool index value
787 // by seaching the index map. Returns zero (0) if there is no mapped
788 // value for the old constant pool index.
789 int VM_RedefineClasses::find_new_index(int old_index) {
790 if (_index_map_count == 0) {
791 // map is empty so nothing can be found
792 return 0;
793 }
794
795 if (old_index < 1 || old_index >= _index_map_p->length()) {
796 // The old_index is out of range so it is not mapped. This should
797 // not happen in regular constant pool merging use, but it can
798 // happen if a corrupt annotation is processed.
799 return 0;
800 }
801
802 int value = _index_map_p->at(old_index);
803 if (value == -1) {
804 // the old_index is not mapped
805 return 0;
806 }
807
808 return value;
809 } // end find_new_index()
810
811
812 // Returns true if the current mismatch is due to a resolved/unresolved
813 // class pair. Otherwise, returns false.
814 bool VM_RedefineClasses::is_unresolved_class_mismatch(constantPoolHandle cp1,
815 int index1, constantPoolHandle cp2, int index2) {
816
817 jbyte t1 = cp1->tag_at(index1).value();
818 if (t1 != JVM_CONSTANT_Class && t1 != JVM_CONSTANT_UnresolvedClass) {
819 return false; // wrong entry type; not our special case
820 }
821
822 jbyte t2 = cp2->tag_at(index2).value();
823 if (t2 != JVM_CONSTANT_Class && t2 != JVM_CONSTANT_UnresolvedClass) {
824 return false; // wrong entry type; not our special case
825 }
826
827 if (t1 == t2) {
828 return false; // not a mismatch; not our special case
829 }
830
831 char *s1 = cp1->klass_name_at(index1)->as_C_string();
832 char *s2 = cp2->klass_name_at(index2)->as_C_string();
833 if (strcmp(s1, s2) != 0) {
834 return false; // strings don't match; not our special case
835 }
836
837 return true; // made it through the gauntlet; this is our special case
838 } // end is_unresolved_class_mismatch()
839
840
841 jvmtiError VM_RedefineClasses::load_new_class_versions(TRAPS) {
842
843 // For consistency allocate memory using os::malloc wrapper.
844 _scratch_classes = (Klass**)
845 os::malloc(sizeof(Klass*) * _class_count, mtClass);
846 if (_scratch_classes == NULL) {
847 return JVMTI_ERROR_OUT_OF_MEMORY;
848 }
849 // Zero initialize the _scratch_classes array.
850 for (int i = 0; i < _class_count; i++) {
851 _scratch_classes[i] = NULL;
852 }
853
854 ResourceMark rm(THREAD);
855
856 JvmtiThreadState *state = JvmtiThreadState::state_for(JavaThread::current());
857 // state can only be NULL if the current thread is exiting which
858 // should not happen since we're trying to do a RedefineClasses
859 guarantee(state != NULL, "exiting thread calling load_new_class_versions");
860 for (int i = 0; i < _class_count; i++) {
861 // Create HandleMark so that any handles created while loading new class
862 // versions are deleted. Constant pools are deallocated while merging
863 // constant pools
864 HandleMark hm(THREAD);
865
866 oop mirror = JNIHandles::resolve_non_null(_class_defs[i].klass);
867 // classes for primitives cannot be redefined
868 if (!is_modifiable_class(mirror)) {
869 return JVMTI_ERROR_UNMODIFIABLE_CLASS;
870 }
871 Klass* the_class_oop = java_lang_Class::as_Klass(mirror);
872 instanceKlassHandle the_class = instanceKlassHandle(THREAD, the_class_oop);
873 Symbol* the_class_sym = the_class->name();
874
875 // RC_TRACE_WITH_THREAD macro has an embedded ResourceMark
876 RC_TRACE_WITH_THREAD(0x00000001, THREAD,
877 ("loading name=%s kind=%d (avail_mem=" UINT64_FORMAT "K)",
878 the_class->external_name(), _class_load_kind,
879 os::available_memory() >> 10));
880
881 ClassFileStream st((u1*) _class_defs[i].class_bytes,
882 _class_defs[i].class_byte_count, (char *)"__VM_RedefineClasses__");
883
884 // Parse the stream.
885 Handle the_class_loader(THREAD, the_class->class_loader());
886 Handle protection_domain(THREAD, the_class->protection_domain());
887 // Set redefined class handle in JvmtiThreadState class.
888 // This redefined class is sent to agent event handler for class file
889 // load hook event.
890 state->set_class_being_redefined(&the_class, _class_load_kind);
891
892 Klass* k = SystemDictionary::parse_stream(the_class_sym,
893 the_class_loader,
894 protection_domain,
895 &st,
896 THREAD);
897 // Clear class_being_redefined just to be sure.
898 state->clear_class_being_redefined();
899
900 // TODO: if this is retransform, and nothing changed we can skip it
901
902 instanceKlassHandle scratch_class (THREAD, k);
903
904 // Need to clean up allocated InstanceKlass if there's an error so assign
905 // the result here. Caller deallocates all the scratch classes in case of
906 // an error.
907 _scratch_classes[i] = k;
908
909 if (HAS_PENDING_EXCEPTION) {
910 Symbol* ex_name = PENDING_EXCEPTION->klass()->name();
911 // RC_TRACE_WITH_THREAD macro has an embedded ResourceMark
912 RC_TRACE_WITH_THREAD(0x00000002, THREAD, ("parse_stream exception: '%s'",
913 ex_name->as_C_string()));
914 CLEAR_PENDING_EXCEPTION;
915
916 if (ex_name == vmSymbols::java_lang_UnsupportedClassVersionError()) {
917 return JVMTI_ERROR_UNSUPPORTED_VERSION;
918 } else if (ex_name == vmSymbols::java_lang_ClassFormatError()) {
919 return JVMTI_ERROR_INVALID_CLASS_FORMAT;
920 } else if (ex_name == vmSymbols::java_lang_ClassCircularityError()) {
921 return JVMTI_ERROR_CIRCULAR_CLASS_DEFINITION;
922 } else if (ex_name == vmSymbols::java_lang_NoClassDefFoundError()) {
923 // The message will be "XXX (wrong name: YYY)"
924 return JVMTI_ERROR_NAMES_DONT_MATCH;
925 } else if (ex_name == vmSymbols::java_lang_OutOfMemoryError()) {
926 return JVMTI_ERROR_OUT_OF_MEMORY;
927 } else { // Just in case more exceptions can be thrown..
928 return JVMTI_ERROR_FAILS_VERIFICATION;
929 }
930 }
931
932 // Ensure class is linked before redefine
933 if (!the_class->is_linked()) {
934 the_class->link_class(THREAD);
935 if (HAS_PENDING_EXCEPTION) {
936 Symbol* ex_name = PENDING_EXCEPTION->klass()->name();
937 // RC_TRACE_WITH_THREAD macro has an embedded ResourceMark
938 RC_TRACE_WITH_THREAD(0x00000002, THREAD, ("link_class exception: '%s'",
939 ex_name->as_C_string()));
940 CLEAR_PENDING_EXCEPTION;
941 if (ex_name == vmSymbols::java_lang_OutOfMemoryError()) {
942 return JVMTI_ERROR_OUT_OF_MEMORY;
943 } else {
944 return JVMTI_ERROR_INTERNAL;
945 }
946 }
947 }
948
949 // Do the validity checks in compare_and_normalize_class_versions()
950 // before verifying the byte codes. By doing these checks first, we
951 // limit the number of functions that require redirection from
952 // the_class to scratch_class. In particular, we don't have to
953 // modify JNI GetSuperclass() and thus won't change its performance.
954 jvmtiError res = compare_and_normalize_class_versions(the_class,
955 scratch_class);
956 if (res != JVMTI_ERROR_NONE) {
957 return res;
958 }
959
960 // verify what the caller passed us
961 {
962 // The bug 6214132 caused the verification to fail.
963 // Information about the_class and scratch_class is temporarily
964 // recorded into jvmtiThreadState. This data is used to redirect
965 // the_class to scratch_class in the JVM_* functions called by the
966 // verifier. Please, refer to jvmtiThreadState.hpp for the detailed
967 // description.
968 RedefineVerifyMark rvm(&the_class, &scratch_class, state);
969 Verifier::verify(
970 scratch_class, Verifier::ThrowException, true, THREAD);
971 }
972
973 if (HAS_PENDING_EXCEPTION) {
974 Symbol* ex_name = PENDING_EXCEPTION->klass()->name();
975 // RC_TRACE_WITH_THREAD macro has an embedded ResourceMark
976 RC_TRACE_WITH_THREAD(0x00000002, THREAD,
977 ("verify_byte_codes exception: '%s'", ex_name->as_C_string()));
978 CLEAR_PENDING_EXCEPTION;
979 if (ex_name == vmSymbols::java_lang_OutOfMemoryError()) {
980 return JVMTI_ERROR_OUT_OF_MEMORY;
981 } else {
982 // tell the caller the bytecodes are bad
983 return JVMTI_ERROR_FAILS_VERIFICATION;
984 }
985 }
986
987 res = merge_cp_and_rewrite(the_class, scratch_class, THREAD);
988 if (res != JVMTI_ERROR_NONE) {
989 return res;
990 }
991
992 if (VerifyMergedCPBytecodes) {
993 // verify what we have done during constant pool merging
994 {
995 RedefineVerifyMark rvm(&the_class, &scratch_class, state);
996 Verifier::verify(scratch_class, Verifier::ThrowException, true, THREAD);
997 }
998
999 if (HAS_PENDING_EXCEPTION) {
1000 Symbol* ex_name = PENDING_EXCEPTION->klass()->name();
1001 // RC_TRACE_WITH_THREAD macro has an embedded ResourceMark
1002 RC_TRACE_WITH_THREAD(0x00000002, THREAD,
1003 ("verify_byte_codes post merge-CP exception: '%s'",
1004 ex_name->as_C_string()));
1005 CLEAR_PENDING_EXCEPTION;
1006 if (ex_name == vmSymbols::java_lang_OutOfMemoryError()) {
1007 return JVMTI_ERROR_OUT_OF_MEMORY;
1008 } else {
1009 // tell the caller that constant pool merging screwed up
1010 return JVMTI_ERROR_INTERNAL;
1011 }
1012 }
1013 }
1014
1015 Rewriter::rewrite(scratch_class, THREAD);
1016 if (!HAS_PENDING_EXCEPTION) {
1017 scratch_class->link_methods(THREAD);
1018 }
1019 if (HAS_PENDING_EXCEPTION) {
1020 Symbol* ex_name = PENDING_EXCEPTION->klass()->name();
1021 CLEAR_PENDING_EXCEPTION;
1022 if (ex_name == vmSymbols::java_lang_OutOfMemoryError()) {
1023 return JVMTI_ERROR_OUT_OF_MEMORY;
1024 } else {
1025 return JVMTI_ERROR_INTERNAL;
1026 }
1027 }
1028
1029 // RC_TRACE_WITH_THREAD macro has an embedded ResourceMark
1030 RC_TRACE_WITH_THREAD(0x00000001, THREAD,
1031 ("loaded name=%s (avail_mem=" UINT64_FORMAT "K)",
1032 the_class->external_name(), os::available_memory() >> 10));
1033 }
1034
1035 return JVMTI_ERROR_NONE;
1036 }
1037
1038
1039 // Map old_index to new_index as needed. scratch_cp is only needed
1040 // for RC_TRACE() calls.
1041 void VM_RedefineClasses::map_index(constantPoolHandle scratch_cp,
1042 int old_index, int new_index) {
1043 if (find_new_index(old_index) != 0) {
1044 // old_index is already mapped
1045 return;
1046 }
1047
1048 if (old_index == new_index) {
1049 // no mapping is needed
1050 return;
1051 }
1052
1053 _index_map_p->at_put(old_index, new_index);
1054 _index_map_count++;
1055
1056 RC_TRACE(0x00040000, ("mapped tag %d at index %d to %d",
1057 scratch_cp->tag_at(old_index).value(), old_index, new_index));
1058 } // end map_index()
1059
1060
1061 // Merge old_cp and scratch_cp and return the results of the merge via
1062 // merge_cp_p. The number of entries in *merge_cp_p is returned via
1063 // merge_cp_length_p. The entries in old_cp occupy the same locations
1064 // in *merge_cp_p. Also creates a map of indices from entries in
1065 // scratch_cp to the corresponding entry in *merge_cp_p. Index map
1066 // entries are only created for entries in scratch_cp that occupy a
1067 // different location in *merged_cp_p.
1068 bool VM_RedefineClasses::merge_constant_pools(constantPoolHandle old_cp,
1069 constantPoolHandle scratch_cp, constantPoolHandle *merge_cp_p,
1070 int *merge_cp_length_p, TRAPS) {
1071
1072 if (merge_cp_p == NULL) {
1073 assert(false, "caller must provide scratch constantPool");
1074 return false; // robustness
1075 }
1076 if (merge_cp_length_p == NULL) {
1077 assert(false, "caller must provide scratch CP length");
1078 return false; // robustness
1079 }
1080 // Worst case we need old_cp->length() + scratch_cp()->length(),
1081 // but the caller might be smart so make sure we have at least
1082 // the minimum.
1083 if ((*merge_cp_p)->length() < old_cp->length()) {
1084 assert(false, "merge area too small");
1085 return false; // robustness
1086 }
1087
1088 RC_TRACE_WITH_THREAD(0x00010000, THREAD,
1089 ("old_cp_len=%d, scratch_cp_len=%d", old_cp->length(),
1090 scratch_cp->length()));
1091
1092 {
1093 // Pass 0:
1094 // The old_cp is copied to *merge_cp_p; this means that any code
1095 // using old_cp does not have to change. This work looks like a
1096 // perfect fit for ConstantPool*::copy_cp_to(), but we need to
1097 // handle one special case:
1098 // - revert JVM_CONSTANT_Class to JVM_CONSTANT_UnresolvedClass
1099 // This will make verification happy.
1100
1101 int old_i; // index into old_cp
1102
1103 // index zero (0) is not used in constantPools
1104 for (old_i = 1; old_i < old_cp->length(); old_i++) {
1105 // leave debugging crumb
1106 jbyte old_tag = old_cp->tag_at(old_i).value();
1107 switch (old_tag) {
1108 case JVM_CONSTANT_Class:
1109 case JVM_CONSTANT_UnresolvedClass:
1110 // revert the copy to JVM_CONSTANT_UnresolvedClass
1111 // May be resolving while calling this so do the same for
1112 // JVM_CONSTANT_UnresolvedClass (klass_name_at() deals with transition)
1113 (*merge_cp_p)->unresolved_klass_at_put(old_i,
1114 old_cp->klass_name_at(old_i));
1115 break;
1116
1117 case JVM_CONSTANT_Double:
1118 case JVM_CONSTANT_Long:
1119 // just copy the entry to *merge_cp_p, but double and long take
1120 // two constant pool entries
1121 ConstantPool::copy_entry_to(old_cp, old_i, *merge_cp_p, old_i, CHECK_0);
1122 old_i++;
1123 break;
1124
1125 default:
1126 // just copy the entry to *merge_cp_p
1127 ConstantPool::copy_entry_to(old_cp, old_i, *merge_cp_p, old_i, CHECK_0);
1128 break;
1129 }
1130 } // end for each old_cp entry
1131
1132 ConstantPool::copy_operands(old_cp, *merge_cp_p, CHECK_0);
1133
1134 // We don't need to sanity check that *merge_cp_length_p is within
1135 // *merge_cp_p bounds since we have the minimum on-entry check above.
1136 (*merge_cp_length_p) = old_i;
1137 }
1138
1139 // merge_cp_len should be the same as old_cp->length() at this point
1140 // so this trace message is really a "warm-and-breathing" message.
1141 RC_TRACE_WITH_THREAD(0x00020000, THREAD,
1142 ("after pass 0: merge_cp_len=%d", *merge_cp_length_p));
1143
1144 int scratch_i; // index into scratch_cp
1145 {
1146 // Pass 1a:
1147 // Compare scratch_cp entries to the old_cp entries that we have
1148 // already copied to *merge_cp_p. In this pass, we are eliminating
1149 // exact duplicates (matching entry at same index) so we only
1150 // compare entries in the common indice range.
1151 int increment = 1;
1152 int pass1a_length = MIN2(old_cp->length(), scratch_cp->length());
1153 for (scratch_i = 1; scratch_i < pass1a_length; scratch_i += increment) {
1154 switch (scratch_cp->tag_at(scratch_i).value()) {
1155 case JVM_CONSTANT_Double:
1156 case JVM_CONSTANT_Long:
1157 // double and long take two constant pool entries
1158 increment = 2;
1159 break;
1160
1161 default:
1162 increment = 1;
1163 break;
1164 }
1165
1166 bool match = scratch_cp->compare_entry_to(scratch_i, *merge_cp_p,
1167 scratch_i, CHECK_0);
1168 if (match) {
1169 // found a match at the same index so nothing more to do
1170 continue;
1171 } else if (is_unresolved_class_mismatch(scratch_cp, scratch_i,
1172 *merge_cp_p, scratch_i)) {
1173 // The mismatch in compare_entry_to() above is because of a
1174 // resolved versus unresolved class entry at the same index
1175 // with the same string value. Since Pass 0 reverted any
1176 // class entries to unresolved class entries in *merge_cp_p,
1177 // we go with the unresolved class entry.
1178 continue;
1179 }
1180
1181 int found_i = scratch_cp->find_matching_entry(scratch_i, *merge_cp_p,
1182 CHECK_0);
1183 if (found_i != 0) {
1184 guarantee(found_i != scratch_i,
1185 "compare_entry_to() and find_matching_entry() do not agree");
1186
1187 // Found a matching entry somewhere else in *merge_cp_p so
1188 // just need a mapping entry.
1189 map_index(scratch_cp, scratch_i, found_i);
1190 continue;
1191 }
1192
1193 // The find_matching_entry() call above could fail to find a match
1194 // due to a resolved versus unresolved class or string entry situation
1195 // like we solved above with the is_unresolved_*_mismatch() calls.
1196 // However, we would have to call is_unresolved_*_mismatch() over
1197 // all of *merge_cp_p (potentially) and that doesn't seem to be
1198 // worth the time.
1199
1200 // No match found so we have to append this entry and any unique
1201 // referenced entries to *merge_cp_p.
1202 append_entry(scratch_cp, scratch_i, merge_cp_p, merge_cp_length_p,
1203 CHECK_0);
1204 }
1205 }
1206
1207 RC_TRACE_WITH_THREAD(0x00020000, THREAD,
1208 ("after pass 1a: merge_cp_len=%d, scratch_i=%d, index_map_len=%d",
1209 *merge_cp_length_p, scratch_i, _index_map_count));
1210
1211 if (scratch_i < scratch_cp->length()) {
1212 // Pass 1b:
1213 // old_cp is smaller than scratch_cp so there are entries in
1214 // scratch_cp that we have not yet processed. We take care of
1215 // those now.
1216 int increment = 1;
1217 for (; scratch_i < scratch_cp->length(); scratch_i += increment) {
1218 switch (scratch_cp->tag_at(scratch_i).value()) {
1219 case JVM_CONSTANT_Double:
1220 case JVM_CONSTANT_Long:
1221 // double and long take two constant pool entries
1222 increment = 2;
1223 break;
1224
1225 default:
1226 increment = 1;
1227 break;
1228 }
1229
1230 int found_i =
1231 scratch_cp->find_matching_entry(scratch_i, *merge_cp_p, CHECK_0);
1232 if (found_i != 0) {
1233 // Found a matching entry somewhere else in *merge_cp_p so
1234 // just need a mapping entry.
1235 map_index(scratch_cp, scratch_i, found_i);
1236 continue;
1237 }
1238
1239 // No match found so we have to append this entry and any unique
1240 // referenced entries to *merge_cp_p.
1241 append_entry(scratch_cp, scratch_i, merge_cp_p, merge_cp_length_p,
1242 CHECK_0);
1243 }
1244
1245 RC_TRACE_WITH_THREAD(0x00020000, THREAD,
1246 ("after pass 1b: merge_cp_len=%d, scratch_i=%d, index_map_len=%d",
1247 *merge_cp_length_p, scratch_i, _index_map_count));
1248 }
1249
1250 return true;
1251 } // end merge_constant_pools()
1252
1253
1254 // Scoped object to clean up the constant pool(s) created for merging
1255 class MergeCPCleaner {
1256 ClassLoaderData* _loader_data;
1257 ConstantPool* _cp;
1258 ConstantPool* _scratch_cp;
1259 public:
1260 MergeCPCleaner(ClassLoaderData* loader_data, ConstantPool* merge_cp) :
1261 _loader_data(loader_data), _cp(merge_cp), _scratch_cp(NULL) {}
1262 ~MergeCPCleaner() {
1263 _loader_data->add_to_deallocate_list(_cp);
1264 if (_scratch_cp != NULL) {
1265 _loader_data->add_to_deallocate_list(_scratch_cp);
1266 }
1267 }
1268 void add_scratch_cp(ConstantPool* scratch_cp) { _scratch_cp = scratch_cp; }
1269 };
1270
1271 // Merge constant pools between the_class and scratch_class and
1272 // potentially rewrite bytecodes in scratch_class to use the merged
1273 // constant pool.
1274 jvmtiError VM_RedefineClasses::merge_cp_and_rewrite(
1275 instanceKlassHandle the_class, instanceKlassHandle scratch_class,
1276 TRAPS) {
1277 // worst case merged constant pool length is old and new combined
1278 int merge_cp_length = the_class->constants()->length()
1279 + scratch_class->constants()->length();
1280
1281 // Constant pools are not easily reused so we allocate a new one
1282 // each time.
1283 // merge_cp is created unsafe for concurrent GC processing. It
1284 // should be marked safe before discarding it. Even though
1285 // garbage, if it crosses a card boundary, it may be scanned
1286 // in order to find the start of the first complete object on the card.
1287 ClassLoaderData* loader_data = the_class->class_loader_data();
1288 ConstantPool* merge_cp_oop =
1289 ConstantPool::allocate(loader_data,
1290 merge_cp_length,
1291 THREAD);
1292 MergeCPCleaner cp_cleaner(loader_data, merge_cp_oop);
1293
1294 HandleMark hm(THREAD); // make sure handles are cleared before
1295 // MergeCPCleaner clears out merge_cp_oop
1296 constantPoolHandle merge_cp(THREAD, merge_cp_oop);
1297
1298 // Get constants() from the old class because it could have been rewritten
1299 // while we were at a safepoint allocating a new constant pool.
1300 constantPoolHandle old_cp(THREAD, the_class->constants());
1301 constantPoolHandle scratch_cp(THREAD, scratch_class->constants());
1302
1303 // If the length changed, the class was redefined out from under us. Return
1304 // an error.
1305 if (merge_cp_length != the_class->constants()->length()
1306 + scratch_class->constants()->length()) {
1307 return JVMTI_ERROR_INTERNAL;
1308 }
1309
1310 // Update the version number of the constant pool
1311 merge_cp->increment_and_save_version(old_cp->version());
1312
1313 ResourceMark rm(THREAD);
1314 _index_map_count = 0;
1315 _index_map_p = new intArray(scratch_cp->length(), -1);
1316
1317 // reference to the cp holder is needed for copy_operands()
1318 merge_cp->set_pool_holder(scratch_class());
1319 bool result = merge_constant_pools(old_cp, scratch_cp, &merge_cp,
1320 &merge_cp_length, THREAD);
1321 merge_cp->set_pool_holder(NULL);
1322
1323 if (!result) {
1324 // The merge can fail due to memory allocation failure or due
1325 // to robustness checks.
1326 return JVMTI_ERROR_INTERNAL;
1327 }
1328
1329 RC_TRACE_WITH_THREAD(0x00010000, THREAD,
1330 ("merge_cp_len=%d, index_map_len=%d", merge_cp_length, _index_map_count));
1331
1332 if (_index_map_count == 0) {
1333 // there is nothing to map between the new and merged constant pools
1334
1335 if (old_cp->length() == scratch_cp->length()) {
1336 // The old and new constant pools are the same length and the
1337 // index map is empty. This means that the three constant pools
1338 // are equivalent (but not the same). Unfortunately, the new
1339 // constant pool has not gone through link resolution nor have
1340 // the new class bytecodes gone through constant pool cache
1341 // rewriting so we can't use the old constant pool with the new
1342 // class.
1343
1344 // toss the merged constant pool at return
1345 } else if (old_cp->length() < scratch_cp->length()) {
1346 // The old constant pool has fewer entries than the new constant
1347 // pool and the index map is empty. This means the new constant
1348 // pool is a superset of the old constant pool. However, the old
1349 // class bytecodes have already gone through constant pool cache
1350 // rewriting so we can't use the new constant pool with the old
1351 // class.
1352
1353 // toss the merged constant pool at return
1354 } else {
1355 // The old constant pool has more entries than the new constant
1356 // pool and the index map is empty. This means that both the old
1357 // and merged constant pools are supersets of the new constant
1358 // pool.
1359
1360 // Replace the new constant pool with a shrunken copy of the
1361 // merged constant pool
1362 set_new_constant_pool(loader_data, scratch_class, merge_cp, merge_cp_length, THREAD);
1363 // The new constant pool replaces scratch_cp so have cleaner clean it up.
1364 // It can't be cleaned up while there are handles to it.
1365 cp_cleaner.add_scratch_cp(scratch_cp());
1366 }
1367 } else {
1368 if (RC_TRACE_ENABLED(0x00040000)) {
1369 // don't want to loop unless we are tracing
1370 int count = 0;
1371 for (int i = 1; i < _index_map_p->length(); i++) {
1372 int value = _index_map_p->at(i);
1373
1374 if (value != -1) {
1375 RC_TRACE_WITH_THREAD(0x00040000, THREAD,
1376 ("index_map[%d]: old=%d new=%d", count, i, value));
1377 count++;
1378 }
1379 }
1380 }
1381
1382 // We have entries mapped between the new and merged constant pools
1383 // so we have to rewrite some constant pool references.
1384 if (!rewrite_cp_refs(scratch_class, THREAD)) {
1385 return JVMTI_ERROR_INTERNAL;
1386 }
1387
1388 // Replace the new constant pool with a shrunken copy of the
1389 // merged constant pool so now the rewritten bytecodes have
1390 // valid references; the previous new constant pool will get
1391 // GCed.
1392 set_new_constant_pool(loader_data, scratch_class, merge_cp, merge_cp_length, THREAD);
1393 // The new constant pool replaces scratch_cp so have cleaner clean it up.
1394 // It can't be cleaned up while there are handles to it.
1395 cp_cleaner.add_scratch_cp(scratch_cp());
1396 }
1397
1398 return JVMTI_ERROR_NONE;
1399 } // end merge_cp_and_rewrite()
1400
1401
1402 // Rewrite constant pool references in klass scratch_class.
1403 bool VM_RedefineClasses::rewrite_cp_refs(instanceKlassHandle scratch_class,
1404 TRAPS) {
1405
1406 // rewrite constant pool references in the methods:
1407 if (!rewrite_cp_refs_in_methods(scratch_class, THREAD)) {
1408 // propagate failure back to caller
1409 return false;
1410 }
1411
1412 // rewrite constant pool references in the class_annotations:
1413 if (!rewrite_cp_refs_in_class_annotations(scratch_class, THREAD)) {
1414 // propagate failure back to caller
1415 return false;
1416 }
1417
1418 // rewrite constant pool references in the fields_annotations:
1419 if (!rewrite_cp_refs_in_fields_annotations(scratch_class, THREAD)) {
1420 // propagate failure back to caller
1421 return false;
1422 }
1423
1424 // rewrite constant pool references in the methods_annotations:
1425 if (!rewrite_cp_refs_in_methods_annotations(scratch_class, THREAD)) {
1426 // propagate failure back to caller
1427 return false;
1428 }
1429
1430 // rewrite constant pool references in the methods_parameter_annotations:
1431 if (!rewrite_cp_refs_in_methods_parameter_annotations(scratch_class,
1432 THREAD)) {
1433 // propagate failure back to caller
1434 return false;
1435 }
1436
1437 // rewrite constant pool references in the methods_default_annotations:
1438 if (!rewrite_cp_refs_in_methods_default_annotations(scratch_class,
1439 THREAD)) {
1440 // propagate failure back to caller
1441 return false;
1442 }
1443
1444 return true;
1445 } // end rewrite_cp_refs()
1446
1447
1448 // Rewrite constant pool references in the methods.
1449 bool VM_RedefineClasses::rewrite_cp_refs_in_methods(
1450 instanceKlassHandle scratch_class, TRAPS) {
1451
1452 Array<Method*>* methods = scratch_class->methods();
1453
1454 if (methods == NULL || methods->length() == 0) {
1455 // no methods so nothing to do
1456 return true;
1457 }
1458
1459 // rewrite constant pool references in the methods:
1460 for (int i = methods->length() - 1; i >= 0; i--) {
1461 methodHandle method(THREAD, methods->at(i));
1462 methodHandle new_method;
1463 rewrite_cp_refs_in_method(method, &new_method, CHECK_false);
1464 if (!new_method.is_null()) {
1465 // the method has been replaced so save the new method version
1466 methods->at_put(i, new_method());
1467 }
1468 }
1469
1470 return true;
1471 }
1472
1473
1474 // Rewrite constant pool references in the specific method. This code
1475 // was adapted from Rewriter::rewrite_method().
1476 void VM_RedefineClasses::rewrite_cp_refs_in_method(methodHandle method,
1477 methodHandle *new_method_p, TRAPS) {
1478
1479 *new_method_p = methodHandle(); // default is no new method
1480
1481 // We cache a pointer to the bytecodes here in code_base. If GC
1482 // moves the Method*, then the bytecodes will also move which
1483 // will likely cause a crash. We create a No_Safepoint_Verifier
1484 // object to detect whether we pass a possible safepoint in this
1485 // code block.
1486 No_Safepoint_Verifier nsv;
1487
1488 // Bytecodes and their length
1489 address code_base = method->code_base();
1490 int code_length = method->code_size();
1491
1492 int bc_length;
1493 for (int bci = 0; bci < code_length; bci += bc_length) {
1494 address bcp = code_base + bci;
1495 Bytecodes::Code c = (Bytecodes::Code)(*bcp);
1496
1497 bc_length = Bytecodes::length_for(c);
1498 if (bc_length == 0) {
1499 // More complicated bytecodes report a length of zero so
1500 // we have to try again a slightly different way.
1501 bc_length = Bytecodes::length_at(method(), bcp);
1502 }
1503
1504 assert(bc_length != 0, "impossible bytecode length");
1505
1506 switch (c) {
1507 case Bytecodes::_ldc:
1508 {
1509 int cp_index = *(bcp + 1);
1510 int new_index = find_new_index(cp_index);
1511
1512 if (StressLdcRewrite && new_index == 0) {
1513 // If we are stressing ldc -> ldc_w rewriting, then we
1514 // always need a new_index value.
1515 new_index = cp_index;
1516 }
1517 if (new_index != 0) {
1518 // the original index is mapped so we have more work to do
1519 if (!StressLdcRewrite && new_index <= max_jubyte) {
1520 // The new value can still use ldc instead of ldc_w
1521 // unless we are trying to stress ldc -> ldc_w rewriting
1522 RC_TRACE_WITH_THREAD(0x00080000, THREAD,
1523 ("%s@" INTPTR_FORMAT " old=%d, new=%d", Bytecodes::name(c),
1524 bcp, cp_index, new_index));
1525 *(bcp + 1) = new_index;
1526 } else {
1527 RC_TRACE_WITH_THREAD(0x00080000, THREAD,
1528 ("%s->ldc_w@" INTPTR_FORMAT " old=%d, new=%d",
1529 Bytecodes::name(c), bcp, cp_index, new_index));
1530 // the new value needs ldc_w instead of ldc
1531 u_char inst_buffer[4]; // max instruction size is 4 bytes
1532 bcp = (address)inst_buffer;
1533 // construct new instruction sequence
1534 *bcp = Bytecodes::_ldc_w;
1535 bcp++;
1536 // Rewriter::rewrite_method() does not rewrite ldc -> ldc_w.
1537 // See comment below for difference between put_Java_u2()
1538 // and put_native_u2().
1539 Bytes::put_Java_u2(bcp, new_index);
1540
1541 Relocator rc(method, NULL /* no RelocatorListener needed */);
1542 methodHandle m;
1543 {
1544 Pause_No_Safepoint_Verifier pnsv(&nsv);
1545
1546 // ldc is 2 bytes and ldc_w is 3 bytes
1547 m = rc.insert_space_at(bci, 3, inst_buffer, THREAD);
1548 if (m.is_null() || HAS_PENDING_EXCEPTION) {
1549 guarantee(false, "insert_space_at() failed");
1550 }
1551 }
1552
1553 // return the new method so that the caller can update
1554 // the containing class
1555 *new_method_p = method = m;
1556 // switch our bytecode processing loop from the old method
1557 // to the new method
1558 code_base = method->code_base();
1559 code_length = method->code_size();
1560 bcp = code_base + bci;
1561 c = (Bytecodes::Code)(*bcp);
1562 bc_length = Bytecodes::length_for(c);
1563 assert(bc_length != 0, "sanity check");
1564 } // end we need ldc_w instead of ldc
1565 } // end if there is a mapped index
1566 } break;
1567
1568 // these bytecodes have a two-byte constant pool index
1569 case Bytecodes::_anewarray : // fall through
1570 case Bytecodes::_checkcast : // fall through
1571 case Bytecodes::_getfield : // fall through
1572 case Bytecodes::_getstatic : // fall through
1573 case Bytecodes::_instanceof : // fall through
1574 case Bytecodes::_invokeinterface: // fall through
1575 case Bytecodes::_invokespecial : // fall through
1576 case Bytecodes::_invokestatic : // fall through
1577 case Bytecodes::_invokevirtual : // fall through
1578 case Bytecodes::_ldc_w : // fall through
1579 case Bytecodes::_ldc2_w : // fall through
1580 case Bytecodes::_multianewarray : // fall through
1581 case Bytecodes::_new : // fall through
1582 case Bytecodes::_putfield : // fall through
1583 case Bytecodes::_putstatic :
1584 {
1585 address p = bcp + 1;
1586 int cp_index = Bytes::get_Java_u2(p);
1587 int new_index = find_new_index(cp_index);
1588 if (new_index != 0) {
1589 // the original index is mapped so update w/ new value
1590 RC_TRACE_WITH_THREAD(0x00080000, THREAD,
1591 ("%s@" INTPTR_FORMAT " old=%d, new=%d", Bytecodes::name(c),
1592 bcp, cp_index, new_index));
1593 // Rewriter::rewrite_method() uses put_native_u2() in this
1594 // situation because it is reusing the constant pool index
1595 // location for a native index into the ConstantPoolCache.
1596 // Since we are updating the constant pool index prior to
1597 // verification and ConstantPoolCache initialization, we
1598 // need to keep the new index in Java byte order.
1599 Bytes::put_Java_u2(p, new_index);
1600 }
1601 } break;
1602 }
1603 } // end for each bytecode
1604 } // end rewrite_cp_refs_in_method()
1605
1606
1607 // Rewrite constant pool references in the class_annotations field.
1608 bool VM_RedefineClasses::rewrite_cp_refs_in_class_annotations(
1609 instanceKlassHandle scratch_class, TRAPS) {
1610
1611 AnnotationArray* class_annotations = scratch_class->class_annotations();
1612 if (class_annotations == NULL || class_annotations->length() == 0) {
1613 // no class_annotations so nothing to do
1614 return true;
1615 }
1616
1617 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1618 ("class_annotations length=%d", class_annotations->length()));
1619
1620 int byte_i = 0; // byte index into class_annotations
1621 return rewrite_cp_refs_in_annotations_typeArray(class_annotations, byte_i,
1622 THREAD);
1623 }
1624
1625
1626 // Rewrite constant pool references in an annotations typeArray. This
1627 // "structure" is adapted from the RuntimeVisibleAnnotations_attribute
1628 // that is described in section 4.8.15 of the 2nd-edition of the VM spec:
1629 //
1630 // annotations_typeArray {
1631 // u2 num_annotations;
1632 // annotation annotations[num_annotations];
1633 // }
1634 //
1635 bool VM_RedefineClasses::rewrite_cp_refs_in_annotations_typeArray(
1636 AnnotationArray* annotations_typeArray, int &byte_i_ref, TRAPS) {
1637
1638 if ((byte_i_ref + 2) > annotations_typeArray->length()) {
1639 // not enough room for num_annotations field
1640 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1641 ("length() is too small for num_annotations field"));
1642 return false;
1643 }
1644
1645 u2 num_annotations = Bytes::get_Java_u2((address)
1646 annotations_typeArray->adr_at(byte_i_ref));
1647 byte_i_ref += 2;
1648
1649 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1650 ("num_annotations=%d", num_annotations));
1651
1652 int calc_num_annotations = 0;
1653 for (; calc_num_annotations < num_annotations; calc_num_annotations++) {
1654 if (!rewrite_cp_refs_in_annotation_struct(annotations_typeArray,
1655 byte_i_ref, THREAD)) {
1656 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1657 ("bad annotation_struct at %d", calc_num_annotations));
1658 // propagate failure back to caller
1659 return false;
1660 }
1661 }
1662 assert(num_annotations == calc_num_annotations, "sanity check");
1663
1664 return true;
1665 } // end rewrite_cp_refs_in_annotations_typeArray()
1666
1667
1668 // Rewrite constant pool references in the annotation struct portion of
1669 // an annotations_typeArray. This "structure" is from section 4.8.15 of
1670 // the 2nd-edition of the VM spec:
1671 //
1672 // struct annotation {
1673 // u2 type_index;
1674 // u2 num_element_value_pairs;
1675 // {
1676 // u2 element_name_index;
1677 // element_value value;
1678 // } element_value_pairs[num_element_value_pairs];
1679 // }
1680 //
1681 bool VM_RedefineClasses::rewrite_cp_refs_in_annotation_struct(
1682 AnnotationArray* annotations_typeArray, int &byte_i_ref, TRAPS) {
1683 if ((byte_i_ref + 2 + 2) > annotations_typeArray->length()) {
1684 // not enough room for smallest annotation_struct
1685 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1686 ("length() is too small for annotation_struct"));
1687 return false;
1688 }
1689
1690 u2 type_index = rewrite_cp_ref_in_annotation_data(annotations_typeArray,
1691 byte_i_ref, "mapped old type_index=%d", THREAD);
1692
1693 u2 num_element_value_pairs = Bytes::get_Java_u2((address)
1694 annotations_typeArray->adr_at(byte_i_ref));
1695 byte_i_ref += 2;
1696
1697 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1698 ("type_index=%d num_element_value_pairs=%d", type_index,
1699 num_element_value_pairs));
1700
1701 int calc_num_element_value_pairs = 0;
1702 for (; calc_num_element_value_pairs < num_element_value_pairs;
1703 calc_num_element_value_pairs++) {
1704 if ((byte_i_ref + 2) > annotations_typeArray->length()) {
1705 // not enough room for another element_name_index, let alone
1706 // the rest of another component
1707 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1708 ("length() is too small for element_name_index"));
1709 return false;
1710 }
1711
1712 u2 element_name_index = rewrite_cp_ref_in_annotation_data(
1713 annotations_typeArray, byte_i_ref,
1714 "mapped old element_name_index=%d", THREAD);
1715
1716 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1717 ("element_name_index=%d", element_name_index));
1718
1719 if (!rewrite_cp_refs_in_element_value(annotations_typeArray,
1720 byte_i_ref, THREAD)) {
1721 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1722 ("bad element_value at %d", calc_num_element_value_pairs));
1723 // propagate failure back to caller
1724 return false;
1725 }
1726 } // end for each component
1727 assert(num_element_value_pairs == calc_num_element_value_pairs,
1728 "sanity check");
1729
1730 return true;
1731 } // end rewrite_cp_refs_in_annotation_struct()
1732
1733
1734 // Rewrite a constant pool reference at the current position in
1735 // annotations_typeArray if needed. Returns the original constant
1736 // pool reference if a rewrite was not needed or the new constant
1737 // pool reference if a rewrite was needed.
1738 u2 VM_RedefineClasses::rewrite_cp_ref_in_annotation_data(
1739 AnnotationArray* annotations_typeArray, int &byte_i_ref,
1740 const char * trace_mesg, TRAPS) {
1741
1742 address cp_index_addr = (address)
1743 annotations_typeArray->adr_at(byte_i_ref);
1744 u2 old_cp_index = Bytes::get_Java_u2(cp_index_addr);
1745 u2 new_cp_index = find_new_index(old_cp_index);
1746 if (new_cp_index != 0) {
1747 RC_TRACE_WITH_THREAD(0x02000000, THREAD, (trace_mesg, old_cp_index));
1748 Bytes::put_Java_u2(cp_index_addr, new_cp_index);
1749 old_cp_index = new_cp_index;
1750 }
1751 byte_i_ref += 2;
1752 return old_cp_index;
1753 }
1754
1755
1756 // Rewrite constant pool references in the element_value portion of an
1757 // annotations_typeArray. This "structure" is from section 4.8.15.1 of
1758 // the 2nd-edition of the VM spec:
1759 //
1760 // struct element_value {
1761 // u1 tag;
1762 // union {
1763 // u2 const_value_index;
1764 // {
1765 // u2 type_name_index;
1766 // u2 const_name_index;
1767 // } enum_const_value;
1768 // u2 class_info_index;
1769 // annotation annotation_value;
1770 // struct {
1771 // u2 num_values;
1772 // element_value values[num_values];
1773 // } array_value;
1774 // } value;
1775 // }
1776 //
1777 bool VM_RedefineClasses::rewrite_cp_refs_in_element_value(
1778 AnnotationArray* annotations_typeArray, int &byte_i_ref, TRAPS) {
1779
1780 if ((byte_i_ref + 1) > annotations_typeArray->length()) {
1781 // not enough room for a tag let alone the rest of an element_value
1782 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1783 ("length() is too small for a tag"));
1784 return false;
1785 }
1786
1787 u1 tag = annotations_typeArray->at(byte_i_ref);
1788 byte_i_ref++;
1789 RC_TRACE_WITH_THREAD(0x02000000, THREAD, ("tag='%c'", tag));
1790
1791 switch (tag) {
1792 // These BaseType tag values are from Table 4.2 in VM spec:
1793 case 'B': // byte
1794 case 'C': // char
1795 case 'D': // double
1796 case 'F': // float
1797 case 'I': // int
1798 case 'J': // long
1799 case 'S': // short
1800 case 'Z': // boolean
1801
1802 // The remaining tag values are from Table 4.8 in the 2nd-edition of
1803 // the VM spec:
1804 case 's':
1805 {
1806 // For the above tag values (including the BaseType values),
1807 // value.const_value_index is right union field.
1808
1809 if ((byte_i_ref + 2) > annotations_typeArray->length()) {
1810 // not enough room for a const_value_index
1811 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1812 ("length() is too small for a const_value_index"));
1813 return false;
1814 }
1815
1816 u2 const_value_index = rewrite_cp_ref_in_annotation_data(
1817 annotations_typeArray, byte_i_ref,
1818 "mapped old const_value_index=%d", THREAD);
1819
1820 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1821 ("const_value_index=%d", const_value_index));
1822 } break;
1823
1824 case 'e':
1825 {
1826 // for the above tag value, value.enum_const_value is right union field
1827
1828 if ((byte_i_ref + 4) > annotations_typeArray->length()) {
1829 // not enough room for a enum_const_value
1830 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1831 ("length() is too small for a enum_const_value"));
1832 return false;
1833 }
1834
1835 u2 type_name_index = rewrite_cp_ref_in_annotation_data(
1836 annotations_typeArray, byte_i_ref,
1837 "mapped old type_name_index=%d", THREAD);
1838
1839 u2 const_name_index = rewrite_cp_ref_in_annotation_data(
1840 annotations_typeArray, byte_i_ref,
1841 "mapped old const_name_index=%d", THREAD);
1842
1843 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1844 ("type_name_index=%d const_name_index=%d", type_name_index,
1845 const_name_index));
1846 } break;
1847
1848 case 'c':
1849 {
1850 // for the above tag value, value.class_info_index is right union field
1851
1852 if ((byte_i_ref + 2) > annotations_typeArray->length()) {
1853 // not enough room for a class_info_index
1854 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1855 ("length() is too small for a class_info_index"));
1856 return false;
1857 }
1858
1859 u2 class_info_index = rewrite_cp_ref_in_annotation_data(
1860 annotations_typeArray, byte_i_ref,
1861 "mapped old class_info_index=%d", THREAD);
1862
1863 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1864 ("class_info_index=%d", class_info_index));
1865 } break;
1866
1867 case '@':
1868 // For the above tag value, value.attr_value is the right union
1869 // field. This is a nested annotation.
1870 if (!rewrite_cp_refs_in_annotation_struct(annotations_typeArray,
1871 byte_i_ref, THREAD)) {
1872 // propagate failure back to caller
1873 return false;
1874 }
1875 break;
1876
1877 case '[':
1878 {
1879 if ((byte_i_ref + 2) > annotations_typeArray->length()) {
1880 // not enough room for a num_values field
1881 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1882 ("length() is too small for a num_values field"));
1883 return false;
1884 }
1885
1886 // For the above tag value, value.array_value is the right union
1887 // field. This is an array of nested element_value.
1888 u2 num_values = Bytes::get_Java_u2((address)
1889 annotations_typeArray->adr_at(byte_i_ref));
1890 byte_i_ref += 2;
1891 RC_TRACE_WITH_THREAD(0x02000000, THREAD, ("num_values=%d", num_values));
1892
1893 int calc_num_values = 0;
1894 for (; calc_num_values < num_values; calc_num_values++) {
1895 if (!rewrite_cp_refs_in_element_value(
1896 annotations_typeArray, byte_i_ref, THREAD)) {
1897 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1898 ("bad nested element_value at %d", calc_num_values));
1899 // propagate failure back to caller
1900 return false;
1901 }
1902 }
1903 assert(num_values == calc_num_values, "sanity check");
1904 } break;
1905
1906 default:
1907 RC_TRACE_WITH_THREAD(0x02000000, THREAD, ("bad tag=0x%x", tag));
1908 return false;
1909 } // end decode tag field
1910
1911 return true;
1912 } // end rewrite_cp_refs_in_element_value()
1913
1914
1915 // Rewrite constant pool references in a fields_annotations field.
1916 bool VM_RedefineClasses::rewrite_cp_refs_in_fields_annotations(
1917 instanceKlassHandle scratch_class, TRAPS) {
1918
1919 Annotations* sca = scratch_class->annotations();
1920 if (sca == NULL) return true;
1921
1922 Array<AnnotationArray*>* fields_annotations = sca->fields_annotations();
1923
1924 if (fields_annotations == NULL || fields_annotations->length() == 0) {
1925 // no fields_annotations so nothing to do
1926 return true;
1927 }
1928
1929 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1930 ("fields_annotations length=%d", fields_annotations->length()));
1931
1932 for (int i = 0; i < fields_annotations->length(); i++) {
1933 AnnotationArray* field_annotations = fields_annotations->at(i);
1934 if (field_annotations == NULL || field_annotations->length() == 0) {
1935 // this field does not have any annotations so skip it
1936 continue;
1937 }
1938
1939 int byte_i = 0; // byte index into field_annotations
1940 if (!rewrite_cp_refs_in_annotations_typeArray(field_annotations, byte_i,
1941 THREAD)) {
1942 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1943 ("bad field_annotations at %d", i));
1944 // propagate failure back to caller
1945 return false;
1946 }
1947 }
1948
1949 return true;
1950 } // end rewrite_cp_refs_in_fields_annotations()
1951
1952
1953 // Rewrite constant pool references in a methods_annotations field.
1954 bool VM_RedefineClasses::rewrite_cp_refs_in_methods_annotations(
1955 instanceKlassHandle scratch_class, TRAPS) {
1956
1957 Annotations* sca = scratch_class->annotations();
1958 if (sca == NULL) return true;
1959
1960 Array<AnnotationArray*>* methods_annotations = sca->methods_annotations();
1961
1962 if (methods_annotations == NULL || methods_annotations->length() == 0) {
1963 // no methods_annotations so nothing to do
1964 return true;
1965 }
1966
1967 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1968 ("methods_annotations length=%d", methods_annotations->length()));
1969
1970 for (int i = 0; i < methods_annotations->length(); i++) {
1971 AnnotationArray* method_annotations = methods_annotations->at(i);
1972 if (method_annotations == NULL || method_annotations->length() == 0) {
1973 // this method does not have any annotations so skip it
1974 continue;
1975 }
1976
1977 int byte_i = 0; // byte index into method_annotations
1978 if (!rewrite_cp_refs_in_annotations_typeArray(method_annotations, byte_i,
1979 THREAD)) {
1980 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1981 ("bad method_annotations at %d", i));
1982 // propagate failure back to caller
1983 return false;
1984 }
1985 }
1986
1987 return true;
1988 } // end rewrite_cp_refs_in_methods_annotations()
1989
1990
1991 // Rewrite constant pool references in a methods_parameter_annotations
1992 // field. This "structure" is adapted from the
1993 // RuntimeVisibleParameterAnnotations_attribute described in section
1994 // 4.8.17 of the 2nd-edition of the VM spec:
1995 //
1996 // methods_parameter_annotations_typeArray {
1997 // u1 num_parameters;
1998 // {
1999 // u2 num_annotations;
2000 // annotation annotations[num_annotations];
2001 // } parameter_annotations[num_parameters];
2002 // }
2003 //
2004 bool VM_RedefineClasses::rewrite_cp_refs_in_methods_parameter_annotations(
2005 instanceKlassHandle scratch_class, TRAPS) {
2006
2007 Annotations* sca = scratch_class->annotations();
2008 if (sca == NULL) return true;
2009
2010 Array<AnnotationArray*>* methods_parameter_annotations =
2011 sca->methods_parameter_annotations();
2012
2013 if (methods_parameter_annotations == NULL
2014 || methods_parameter_annotations->length() == 0) {
2015 // no methods_parameter_annotations so nothing to do
2016 return true;
2017 }
2018
2019 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
2020 ("methods_parameter_annotations length=%d",
2021 methods_parameter_annotations->length()));
2022
2023 for (int i = 0; i < methods_parameter_annotations->length(); i++) {
2024 AnnotationArray* method_parameter_annotations = methods_parameter_annotations->at(i);
2025 if (method_parameter_annotations == NULL
2026 || method_parameter_annotations->length() == 0) {
2027 // this method does not have any parameter annotations so skip it
2028 continue;
2029 }
2030
2031 if (method_parameter_annotations->length() < 1) {
2032 // not enough room for a num_parameters field
2033 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
2034 ("length() is too small for a num_parameters field at %d", i));
2035 return false;
2036 }
2037
2038 int byte_i = 0; // byte index into method_parameter_annotations
2039
2040 u1 num_parameters = method_parameter_annotations->at(byte_i);
2041 byte_i++;
2042
2043 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
2044 ("num_parameters=%d", num_parameters));
2045
2046 int calc_num_parameters = 0;
2047 for (; calc_num_parameters < num_parameters; calc_num_parameters++) {
2048 if (!rewrite_cp_refs_in_annotations_typeArray(
2049 method_parameter_annotations, byte_i, THREAD)) {
2050 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
2051 ("bad method_parameter_annotations at %d", calc_num_parameters));
2052 // propagate failure back to caller
2053 return false;
2054 }
2055 }
2056 assert(num_parameters == calc_num_parameters, "sanity check");
2057 }
2058
2059 return true;
2060 } // end rewrite_cp_refs_in_methods_parameter_annotations()
2061
2062
2063 // Rewrite constant pool references in a methods_default_annotations
2064 // field. This "structure" is adapted from the AnnotationDefault_attribute
2065 // that is described in section 4.8.19 of the 2nd-edition of the VM spec:
2066 //
2067 // methods_default_annotations_typeArray {
2068 // element_value default_value;
2069 // }
2070 //
2071 bool VM_RedefineClasses::rewrite_cp_refs_in_methods_default_annotations(
2072 instanceKlassHandle scratch_class, TRAPS) {
2073
2074 Annotations* sca = scratch_class->annotations();
2075 if (sca == NULL) return true;
2076
2077 Array<AnnotationArray*>* methods_default_annotations =
2078 sca->methods_default_annotations();
2079
2080 if (methods_default_annotations == NULL
2081 || methods_default_annotations->length() == 0) {
2082 // no methods_default_annotations so nothing to do
2083 return true;
2084 }
2085
2086 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
2087 ("methods_default_annotations length=%d",
2088 methods_default_annotations->length()));
2089
2090 for (int i = 0; i < methods_default_annotations->length(); i++) {
2091 AnnotationArray* method_default_annotations = methods_default_annotations->at(i);
2092 if (method_default_annotations == NULL
2093 || method_default_annotations->length() == 0) {
2094 // this method does not have any default annotations so skip it
2095 continue;
2096 }
2097
2098 int byte_i = 0; // byte index into method_default_annotations
2099
2100 if (!rewrite_cp_refs_in_element_value(
2101 method_default_annotations, byte_i, THREAD)) {
2102 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
2103 ("bad default element_value at %d", i));
2104 // propagate failure back to caller
2105 return false;
2106 }
2107 }
2108
2109 return true;
2110 } // end rewrite_cp_refs_in_methods_default_annotations()
2111
2112
2113 // Rewrite constant pool references in the method's stackmap table.
2114 // These "structures" are adapted from the StackMapTable_attribute that
2115 // is described in section 4.8.4 of the 6.0 version of the VM spec
2116 // (dated 2005.10.26):
2117 // file:///net/quincunx.sfbay/export/gbracha/ClassFile-Java6.pdf
2118 //
2119 // stack_map {
2120 // u2 number_of_entries;
2121 // stack_map_frame entries[number_of_entries];
2122 // }
2123 //
2124 void VM_RedefineClasses::rewrite_cp_refs_in_stack_map_table(
2125 methodHandle method, TRAPS) {
2126
2127 if (!method->has_stackmap_table()) {
2128 return;
2129 }
2130
2131 AnnotationArray* stackmap_data = method->stackmap_data();
2132 address stackmap_p = (address)stackmap_data->adr_at(0);
2133 address stackmap_end = stackmap_p + stackmap_data->length();
2134
2135 assert(stackmap_p + 2 <= stackmap_end, "no room for number_of_entries");
2136 u2 number_of_entries = Bytes::get_Java_u2(stackmap_p);
2137 stackmap_p += 2;
2138
2139 RC_TRACE_WITH_THREAD(0x04000000, THREAD,
2140 ("number_of_entries=%u", number_of_entries));
2141
2142 // walk through each stack_map_frame
2143 u2 calc_number_of_entries = 0;
2144 for (; calc_number_of_entries < number_of_entries; calc_number_of_entries++) {
2145 // The stack_map_frame structure is a u1 frame_type followed by
2146 // 0 or more bytes of data:
2147 //
2148 // union stack_map_frame {
2149 // same_frame;
2150 // same_locals_1_stack_item_frame;
2151 // same_locals_1_stack_item_frame_extended;
2152 // chop_frame;
2153 // same_frame_extended;
2154 // append_frame;
2155 // full_frame;
2156 // }
2157
2158 assert(stackmap_p + 1 <= stackmap_end, "no room for frame_type");
2159 // The Linux compiler does not like frame_type to be u1 or u2. It
2160 // issues the following warning for the first if-statement below:
2161 //
2162 // "warning: comparison is always true due to limited range of data type"
2163 //
2164 u4 frame_type = *stackmap_p;
2165 stackmap_p++;
2166
2167 // same_frame {
2168 // u1 frame_type = SAME; /* 0-63 */
2169 // }
2170 if (frame_type >= 0 && frame_type <= 63) {
2171 // nothing more to do for same_frame
2172 }
2173
2174 // same_locals_1_stack_item_frame {
2175 // u1 frame_type = SAME_LOCALS_1_STACK_ITEM; /* 64-127 */
2176 // verification_type_info stack[1];
2177 // }
2178 else if (frame_type >= 64 && frame_type <= 127) {
2179 rewrite_cp_refs_in_verification_type_info(stackmap_p, stackmap_end,
2180 calc_number_of_entries, frame_type, THREAD);
2181 }
2182
2183 // reserved for future use
2184 else if (frame_type >= 128 && frame_type <= 246) {
2185 // nothing more to do for reserved frame_types
2186 }
2187
2188 // same_locals_1_stack_item_frame_extended {
2189 // u1 frame_type = SAME_LOCALS_1_STACK_ITEM_EXTENDED; /* 247 */
2190 // u2 offset_delta;
2191 // verification_type_info stack[1];
2192 // }
2193 else if (frame_type == 247) {
2194 stackmap_p += 2;
2195 rewrite_cp_refs_in_verification_type_info(stackmap_p, stackmap_end,
2196 calc_number_of_entries, frame_type, THREAD);
2197 }
2198
2199 // chop_frame {
2200 // u1 frame_type = CHOP; /* 248-250 */
2201 // u2 offset_delta;
2202 // }
2203 else if (frame_type >= 248 && frame_type <= 250) {
2204 stackmap_p += 2;
2205 }
2206
2207 // same_frame_extended {
2208 // u1 frame_type = SAME_FRAME_EXTENDED; /* 251*/
2209 // u2 offset_delta;
2210 // }
2211 else if (frame_type == 251) {
2212 stackmap_p += 2;
2213 }
2214
2215 // append_frame {
2216 // u1 frame_type = APPEND; /* 252-254 */
2217 // u2 offset_delta;
2218 // verification_type_info locals[frame_type - 251];
2219 // }
2220 else if (frame_type >= 252 && frame_type <= 254) {
2221 assert(stackmap_p + 2 <= stackmap_end,
2222 "no room for offset_delta");
2223 stackmap_p += 2;
2224 u1 len = frame_type - 251;
2225 for (u1 i = 0; i < len; i++) {
2226 rewrite_cp_refs_in_verification_type_info(stackmap_p, stackmap_end,
2227 calc_number_of_entries, frame_type, THREAD);
2228 }
2229 }
2230
2231 // full_frame {
2232 // u1 frame_type = FULL_FRAME; /* 255 */
2233 // u2 offset_delta;
2234 // u2 number_of_locals;
2235 // verification_type_info locals[number_of_locals];
2236 // u2 number_of_stack_items;
2237 // verification_type_info stack[number_of_stack_items];
2238 // }
2239 else if (frame_type == 255) {
2240 assert(stackmap_p + 2 + 2 <= stackmap_end,
2241 "no room for smallest full_frame");
2242 stackmap_p += 2;
2243
2244 u2 number_of_locals = Bytes::get_Java_u2(stackmap_p);
2245 stackmap_p += 2;
2246
2247 for (u2 locals_i = 0; locals_i < number_of_locals; locals_i++) {
2248 rewrite_cp_refs_in_verification_type_info(stackmap_p, stackmap_end,
2249 calc_number_of_entries, frame_type, THREAD);
2250 }
2251
2252 // Use the largest size for the number_of_stack_items, but only get
2253 // the right number of bytes.
2254 u2 number_of_stack_items = Bytes::get_Java_u2(stackmap_p);
2255 stackmap_p += 2;
2256
2257 for (u2 stack_i = 0; stack_i < number_of_stack_items; stack_i++) {
2258 rewrite_cp_refs_in_verification_type_info(stackmap_p, stackmap_end,
2259 calc_number_of_entries, frame_type, THREAD);
2260 }
2261 }
2262 } // end while there is a stack_map_frame
2263 assert(number_of_entries == calc_number_of_entries, "sanity check");
2264 } // end rewrite_cp_refs_in_stack_map_table()
2265
2266
2267 // Rewrite constant pool references in the verification type info
2268 // portion of the method's stackmap table. These "structures" are
2269 // adapted from the StackMapTable_attribute that is described in
2270 // section 4.8.4 of the 6.0 version of the VM spec (dated 2005.10.26):
2271 // file:///net/quincunx.sfbay/export/gbracha/ClassFile-Java6.pdf
2272 //
2273 // The verification_type_info structure is a u1 tag followed by 0 or
2274 // more bytes of data:
2275 //
2276 // union verification_type_info {
2277 // Top_variable_info;
2278 // Integer_variable_info;
2279 // Float_variable_info;
2280 // Long_variable_info;
2281 // Double_variable_info;
2282 // Null_variable_info;
2283 // UninitializedThis_variable_info;
2284 // Object_variable_info;
2285 // Uninitialized_variable_info;
2286 // }
2287 //
2288 void VM_RedefineClasses::rewrite_cp_refs_in_verification_type_info(
2289 address& stackmap_p_ref, address stackmap_end, u2 frame_i,
2290 u1 frame_type, TRAPS) {
2291
2292 assert(stackmap_p_ref + 1 <= stackmap_end, "no room for tag");
2293 u1 tag = *stackmap_p_ref;
2294 stackmap_p_ref++;
2295
2296 switch (tag) {
2297 // Top_variable_info {
2298 // u1 tag = ITEM_Top; /* 0 */
2299 // }
2300 // verificationType.hpp has zero as ITEM_Bogus instead of ITEM_Top
2301 case 0: // fall through
2302
2303 // Integer_variable_info {
2304 // u1 tag = ITEM_Integer; /* 1 */
2305 // }
2306 case ITEM_Integer: // fall through
2307
2308 // Float_variable_info {
2309 // u1 tag = ITEM_Float; /* 2 */
2310 // }
2311 case ITEM_Float: // fall through
2312
2313 // Double_variable_info {
2314 // u1 tag = ITEM_Double; /* 3 */
2315 // }
2316 case ITEM_Double: // fall through
2317
2318 // Long_variable_info {
2319 // u1 tag = ITEM_Long; /* 4 */
2320 // }
2321 case ITEM_Long: // fall through
2322
2323 // Null_variable_info {
2324 // u1 tag = ITEM_Null; /* 5 */
2325 // }
2326 case ITEM_Null: // fall through
2327
2328 // UninitializedThis_variable_info {
2329 // u1 tag = ITEM_UninitializedThis; /* 6 */
2330 // }
2331 case ITEM_UninitializedThis:
2332 // nothing more to do for the above tag types
2333 break;
2334
2335 // Object_variable_info {
2336 // u1 tag = ITEM_Object; /* 7 */
2337 // u2 cpool_index;
2338 // }
2339 case ITEM_Object:
2340 {
2341 assert(stackmap_p_ref + 2 <= stackmap_end, "no room for cpool_index");
2342 u2 cpool_index = Bytes::get_Java_u2(stackmap_p_ref);
2343 u2 new_cp_index = find_new_index(cpool_index);
2344 if (new_cp_index != 0) {
2345 RC_TRACE_WITH_THREAD(0x04000000, THREAD,
2346 ("mapped old cpool_index=%d", cpool_index));
2347 Bytes::put_Java_u2(stackmap_p_ref, new_cp_index);
2348 cpool_index = new_cp_index;
2349 }
2350 stackmap_p_ref += 2;
2351
2352 RC_TRACE_WITH_THREAD(0x04000000, THREAD,
2353 ("frame_i=%u, frame_type=%u, cpool_index=%d", frame_i,
2354 frame_type, cpool_index));
2355 } break;
2356
2357 // Uninitialized_variable_info {
2358 // u1 tag = ITEM_Uninitialized; /* 8 */
2359 // u2 offset;
2360 // }
2361 case ITEM_Uninitialized:
2362 assert(stackmap_p_ref + 2 <= stackmap_end, "no room for offset");
2363 stackmap_p_ref += 2;
2364 break;
2365
2366 default:
2367 RC_TRACE_WITH_THREAD(0x04000000, THREAD,
2368 ("frame_i=%u, frame_type=%u, bad tag=0x%x", frame_i, frame_type, tag));
2369 ShouldNotReachHere();
2370 break;
2371 } // end switch (tag)
2372 } // end rewrite_cp_refs_in_verification_type_info()
2373
2374
2375 // Change the constant pool associated with klass scratch_class to
2376 // scratch_cp. If shrink is true, then scratch_cp_length elements
2377 // are copied from scratch_cp to a smaller constant pool and the
2378 // smaller constant pool is associated with scratch_class.
2379 void VM_RedefineClasses::set_new_constant_pool(
2380 ClassLoaderData* loader_data,
2381 instanceKlassHandle scratch_class, constantPoolHandle scratch_cp,
2382 int scratch_cp_length, TRAPS) {
2383 assert(scratch_cp->length() >= scratch_cp_length, "sanity check");
2384
2385 // scratch_cp is a merged constant pool and has enough space for a
2386 // worst case merge situation. We want to associate the minimum
2387 // sized constant pool with the klass to save space.
2388 constantPoolHandle smaller_cp(THREAD,
2389 ConstantPool::allocate(loader_data, scratch_cp_length, THREAD));
2390
2391 // preserve version() value in the smaller copy
2392 int version = scratch_cp->version();
2393 assert(version != 0, "sanity check");
2394 smaller_cp->set_version(version);
2395
2396 // attach klass to new constant pool
2397 // reference to the cp holder is needed for copy_operands()
2398 smaller_cp->set_pool_holder(scratch_class());
2399
2400 scratch_cp->copy_cp_to(1, scratch_cp_length - 1, smaller_cp, 1, THREAD);
2401 scratch_cp = smaller_cp;
2402
2403 // attach new constant pool to klass
2404 scratch_class->set_constants(scratch_cp());
2405
2406 int i; // for portability
2407
2408 // update each field in klass to use new constant pool indices as needed
2409 for (JavaFieldStream fs(scratch_class); !fs.done(); fs.next()) {
2410 jshort cur_index = fs.name_index();
2411 jshort new_index = find_new_index(cur_index);
2412 if (new_index != 0) {
2413 RC_TRACE_WITH_THREAD(0x00080000, THREAD,
2414 ("field-name_index change: %d to %d", cur_index, new_index));
2415 fs.set_name_index(new_index);
2416 }
2417 cur_index = fs.signature_index();
2418 new_index = find_new_index(cur_index);
2419 if (new_index != 0) {
2420 RC_TRACE_WITH_THREAD(0x00080000, THREAD,
2421 ("field-signature_index change: %d to %d", cur_index, new_index));
2422 fs.set_signature_index(new_index);
2423 }
2424 cur_index = fs.initval_index();
2425 new_index = find_new_index(cur_index);
2426 if (new_index != 0) {
2427 RC_TRACE_WITH_THREAD(0x00080000, THREAD,
2428 ("field-initval_index change: %d to %d", cur_index, new_index));
2429 fs.set_initval_index(new_index);
2430 }
2431 cur_index = fs.generic_signature_index();
2432 new_index = find_new_index(cur_index);
2433 if (new_index != 0) {
2434 RC_TRACE_WITH_THREAD(0x00080000, THREAD,
2435 ("field-generic_signature change: %d to %d", cur_index, new_index));
2436 fs.set_generic_signature_index(new_index);
2437 }
2438 } // end for each field
2439
2440 // Update constant pool indices in the inner classes info to use
2441 // new constant indices as needed. The inner classes info is a
2442 // quadruple:
2443 // (inner_class_info, outer_class_info, inner_name, inner_access_flags)
2444 InnerClassesIterator iter(scratch_class);
2445 for (; !iter.done(); iter.next()) {
2446 int cur_index = iter.inner_class_info_index();
2447 if (cur_index == 0) {
2448 continue; // JVM spec. allows null inner class refs so skip it
2449 }
2450 int new_index = find_new_index(cur_index);
2451 if (new_index != 0) {
2452 RC_TRACE_WITH_THREAD(0x00080000, THREAD,
2453 ("inner_class_info change: %d to %d", cur_index, new_index));
2454 iter.set_inner_class_info_index(new_index);
2455 }
2456 cur_index = iter.outer_class_info_index();
2457 new_index = find_new_index(cur_index);
2458 if (new_index != 0) {
2459 RC_TRACE_WITH_THREAD(0x00080000, THREAD,
2460 ("outer_class_info change: %d to %d", cur_index, new_index));
2461 iter.set_outer_class_info_index(new_index);
2462 }
2463 cur_index = iter.inner_name_index();
2464 new_index = find_new_index(cur_index);
2465 if (new_index != 0) {
2466 RC_TRACE_WITH_THREAD(0x00080000, THREAD,
2467 ("inner_name change: %d to %d", cur_index, new_index));
2468 iter.set_inner_name_index(new_index);
2469 }
2470 } // end for each inner class
2471
2472 // Attach each method in klass to the new constant pool and update
2473 // to use new constant pool indices as needed:
2474 Array<Method*>* methods = scratch_class->methods();
2475 for (i = methods->length() - 1; i >= 0; i--) {
2476 methodHandle method(THREAD, methods->at(i));
2477 method->set_constants(scratch_cp());
2478
2479 int new_index = find_new_index(method->name_index());
2480 if (new_index != 0) {
2481 RC_TRACE_WITH_THREAD(0x00080000, THREAD,
2482 ("method-name_index change: %d to %d", method->name_index(),
2483 new_index));
2484 method->set_name_index(new_index);
2485 }
2486 new_index = find_new_index(method->signature_index());
2487 if (new_index != 0) {
2488 RC_TRACE_WITH_THREAD(0x00080000, THREAD,
2489 ("method-signature_index change: %d to %d",
2490 method->signature_index(), new_index));
2491 method->set_signature_index(new_index);
2492 }
2493 new_index = find_new_index(method->generic_signature_index());
2494 if (new_index != 0) {
2495 RC_TRACE_WITH_THREAD(0x00080000, THREAD,
2496 ("method-generic_signature_index change: %d to %d",
2497 method->generic_signature_index(), new_index));
2498 method->set_generic_signature_index(new_index);
2499 }
2500
2501 // Update constant pool indices in the method's checked exception
2502 // table to use new constant indices as needed.
2503 int cext_length = method->checked_exceptions_length();
2504 if (cext_length > 0) {
2505 CheckedExceptionElement * cext_table =
2506 method->checked_exceptions_start();
2507 for (int j = 0; j < cext_length; j++) {
2508 int cur_index = cext_table[j].class_cp_index;
2509 int new_index = find_new_index(cur_index);
2510 if (new_index != 0) {
2511 RC_TRACE_WITH_THREAD(0x00080000, THREAD,
2512 ("cext-class_cp_index change: %d to %d", cur_index, new_index));
2513 cext_table[j].class_cp_index = (u2)new_index;
2514 }
2515 } // end for each checked exception table entry
2516 } // end if there are checked exception table entries
2517
2518 // Update each catch type index in the method's exception table
2519 // to use new constant pool indices as needed. The exception table
2520 // holds quadruple entries of the form:
2521 // (beg_bci, end_bci, handler_bci, klass_index)
2522
2523 ExceptionTable ex_table(method());
2524 int ext_length = ex_table.length();
2525
2526 for (int j = 0; j < ext_length; j ++) {
2527 int cur_index = ex_table.catch_type_index(j);
2528 int new_index = find_new_index(cur_index);
2529 if (new_index != 0) {
2530 RC_TRACE_WITH_THREAD(0x00080000, THREAD,
2531 ("ext-klass_index change: %d to %d", cur_index, new_index));
2532 ex_table.set_catch_type_index(j, new_index);
2533 }
2534 } // end for each exception table entry
2535
2536 // Update constant pool indices in the method's local variable
2537 // table to use new constant indices as needed. The local variable
2538 // table hold sextuple entries of the form:
2539 // (start_pc, length, name_index, descriptor_index, signature_index, slot)
2540 int lvt_length = method->localvariable_table_length();
2541 if (lvt_length > 0) {
2542 LocalVariableTableElement * lv_table =
2543 method->localvariable_table_start();
2544 for (int j = 0; j < lvt_length; j++) {
2545 int cur_index = lv_table[j].name_cp_index;
2546 int new_index = find_new_index(cur_index);
2547 if (new_index != 0) {
2548 RC_TRACE_WITH_THREAD(0x00080000, THREAD,
2549 ("lvt-name_cp_index change: %d to %d", cur_index, new_index));
2550 lv_table[j].name_cp_index = (u2)new_index;
2551 }
2552 cur_index = lv_table[j].descriptor_cp_index;
2553 new_index = find_new_index(cur_index);
2554 if (new_index != 0) {
2555 RC_TRACE_WITH_THREAD(0x00080000, THREAD,
2556 ("lvt-descriptor_cp_index change: %d to %d", cur_index,
2557 new_index));
2558 lv_table[j].descriptor_cp_index = (u2)new_index;
2559 }
2560 cur_index = lv_table[j].signature_cp_index;
2561 new_index = find_new_index(cur_index);
2562 if (new_index != 0) {
2563 RC_TRACE_WITH_THREAD(0x00080000, THREAD,
2564 ("lvt-signature_cp_index change: %d to %d", cur_index, new_index));
2565 lv_table[j].signature_cp_index = (u2)new_index;
2566 }
2567 } // end for each local variable table entry
2568 } // end if there are local variable table entries
2569
2570 rewrite_cp_refs_in_stack_map_table(method, THREAD);
2571 } // end for each method
2572 } // end set_new_constant_pool()
2573
2574
2575 void VM_RedefineClasses::adjust_array_vtable(Klass* k_oop) {
2576 ArrayKlass* ak = ArrayKlass::cast(k_oop);
2577 bool trace_name_printed = false;
2578 ak->vtable()->adjust_method_entries(_matching_old_methods,
2579 _matching_new_methods,
2580 _matching_methods_length,
2581 &trace_name_printed);
2582 }
2583
2584 // Unevolving classes may point to methods of the_class directly
2585 // from their constant pool caches, itables, and/or vtables. We
2586 // use the SystemDictionary::classes_do() facility and this helper
2587 // to fix up these pointers.
2588 //
2589 // Note: We currently don't support updating the vtable in
2590 // arrayKlassOops. See Open Issues in jvmtiRedefineClasses.hpp.
2591 void VM_RedefineClasses::adjust_cpool_cache_and_vtable(Klass* k_oop,
2592 ClassLoaderData* initiating_loader,
2593 TRAPS) {
2594 Klass *k = k_oop;
2595 if (k->oop_is_instance()) {
2596 HandleMark hm(THREAD);
2597 InstanceKlass *ik = (InstanceKlass *) k;
2598
2599 // HotSpot specific optimization! HotSpot does not currently
2600 // support delegation from the bootstrap class loader to a
2601 // user-defined class loader. This means that if the bootstrap
2602 // class loader is the initiating class loader, then it will also
2603 // be the defining class loader. This also means that classes
2604 // loaded by the bootstrap class loader cannot refer to classes
2605 // loaded by a user-defined class loader. Note: a user-defined
2606 // class loader can delegate to the bootstrap class loader.
2607 //
2608 // If the current class being redefined has a user-defined class
2609 // loader as its defining class loader, then we can skip all
2610 // classes loaded by the bootstrap class loader.
2611 bool is_user_defined =
2612 InstanceKlass::cast(_the_class_oop)->class_loader() != NULL;
2613 if (is_user_defined && ik->class_loader() == NULL) {
2614 return;
2615 }
2616
2617 // If the class being redefined is java.lang.Object, we need to fix all
2618 // array class vtables also
2619 if (_the_class_oop == SystemDictionary::Object_klass()) {
2620 ik->array_klasses_do(adjust_array_vtable);
2621 }
2622
2623 // This is a very busy routine. We don't want too much tracing
2624 // printed out.
2625 bool trace_name_printed = false;
2626
2627 // Very noisy: only enable this call if you are trying to determine
2628 // that a specific class gets found by this routine.
2629 // RC_TRACE macro has an embedded ResourceMark
2630 // RC_TRACE_WITH_THREAD(0x00100000, THREAD,
2631 // ("adjust check: name=%s", ik->external_name()));
2632 // trace_name_printed = true;
2633
2634 // Fix the vtable embedded in the_class and subclasses of the_class,
2635 // if one exists. We discard scratch_class and we don't keep an
2636 // InstanceKlass around to hold obsolete methods so we don't have
2637 // any other InstanceKlass embedded vtables to update. The vtable
2638 // holds the Method*s for virtual (but not final) methods.
2639 if (ik->vtable_length() > 0 && ik->is_subtype_of(_the_class_oop)) {
2640 // ik->vtable() creates a wrapper object; rm cleans it up
2641 ResourceMark rm(THREAD);
2642 ik->vtable()->adjust_method_entries(_matching_old_methods,
2643 _matching_new_methods,
2644 _matching_methods_length,
2645 &trace_name_printed);
2646 }
2647
2648 // If the current class has an itable and we are either redefining an
2649 // interface or if the current class is a subclass of the_class, then
2650 // we potentially have to fix the itable. If we are redefining an
2651 // interface, then we have to call adjust_method_entries() for
2652 // every InstanceKlass that has an itable since there isn't a
2653 // subclass relationship between an interface and an InstanceKlass.
2654 if (ik->itable_length() > 0 && (_the_class_oop->is_interface()
2655 || ik->is_subclass_of(_the_class_oop))) {
2656 // ik->itable() creates a wrapper object; rm cleans it up
2657 ResourceMark rm(THREAD);
2658 ik->itable()->adjust_method_entries(_matching_old_methods,
2659 _matching_new_methods,
2660 _matching_methods_length,
2661 &trace_name_printed);
2662 }
2663
2664 // The constant pools in other classes (other_cp) can refer to
2665 // methods in the_class. We have to update method information in
2666 // other_cp's cache. If other_cp has a previous version, then we
2667 // have to repeat the process for each previous version. The
2668 // constant pool cache holds the Method*s for non-virtual
2669 // methods and for virtual, final methods.
2670 //
2671 // Special case: if the current class is the_class, then new_cp
2672 // has already been attached to the_class and old_cp has already
2673 // been added as a previous version. The new_cp doesn't have any
2674 // cached references to old methods so it doesn't need to be
2675 // updated. We can simply start with the previous version(s) in
2676 // that case.
2677 constantPoolHandle other_cp;
2678 ConstantPoolCache* cp_cache;
2679
2680 if (k_oop != _the_class_oop) {
2681 // this klass' constant pool cache may need adjustment
2682 other_cp = constantPoolHandle(ik->constants());
2683 cp_cache = other_cp->cache();
2684 if (cp_cache != NULL) {
2685 cp_cache->adjust_method_entries(_matching_old_methods,
2686 _matching_new_methods,
2687 _matching_methods_length,
2688 &trace_name_printed);
2689 }
2690 }
2691 {
2692 ResourceMark rm(THREAD);
2693 // PreviousVersionInfo objects returned via PreviousVersionWalker
2694 // contain a GrowableArray of handles. We have to clean up the
2695 // GrowableArray _after_ the PreviousVersionWalker destructor
2696 // has destroyed the handles.
2697 {
2698 // the previous versions' constant pool caches may need adjustment
2699 PreviousVersionWalker pvw(ik);
2700 for (PreviousVersionInfo * pv_info = pvw.next_previous_version();
2701 pv_info != NULL; pv_info = pvw.next_previous_version()) {
2702 other_cp = pv_info->prev_constant_pool_handle();
2703 cp_cache = other_cp->cache();
2704 if (cp_cache != NULL) {
2705 cp_cache->adjust_method_entries(_matching_old_methods,
2706 _matching_new_methods,
2707 _matching_methods_length,
2708 &trace_name_printed);
2709 }
2710 }
2711 } // pvw is cleaned up
2712 } // rm is cleaned up
2713 }
2714 }
2715
2716 void VM_RedefineClasses::update_jmethod_ids() {
2717 for (int j = 0; j < _matching_methods_length; ++j) {
2718 Method* old_method = _matching_old_methods[j];
2719 jmethodID jmid = old_method->find_jmethod_id_or_null();
2720 if (jmid != NULL) {
2721 // There is a jmethodID, change it to point to the new method
2722 methodHandle new_method_h(_matching_new_methods[j]);
2723 Method::change_method_associated_with_jmethod_id(jmid, new_method_h());
2724 assert(Method::resolve_jmethod_id(jmid) == _matching_new_methods[j],
2725 "should be replaced");
2726 }
2727 }
2728 }
2729
2730 void VM_RedefineClasses::check_methods_and_mark_as_obsolete(
2731 BitMap *emcp_methods, int * emcp_method_count_p) {
2732 *emcp_method_count_p = 0;
2733 int obsolete_count = 0;
2734 int old_index = 0;
2735 for (int j = 0; j < _matching_methods_length; ++j, ++old_index) {
2736 Method* old_method = _matching_old_methods[j];
2737 Method* new_method = _matching_new_methods[j];
2738 Method* old_array_method;
2739
2740 // Maintain an old_index into the _old_methods array by skipping
2741 // deleted methods
2742 while ((old_array_method = _old_methods->at(old_index)) != old_method) {
2743 ++old_index;
2744 }
2745
2746 if (MethodComparator::methods_EMCP(old_method, new_method)) {
2747 // The EMCP definition from JSR-163 requires the bytecodes to be
2748 // the same with the exception of constant pool indices which may
2749 // differ. However, the constants referred to by those indices
2750 // must be the same.
2751 //
2752 // We use methods_EMCP() for comparison since constant pool
2753 // merging can remove duplicate constant pool entries that were
2754 // present in the old method and removed from the rewritten new
2755 // method. A faster binary comparison function would consider the
2756 // old and new methods to be different when they are actually
2757 // EMCP.
2758 //
2759 // The old and new methods are EMCP and you would think that we
2760 // could get rid of one of them here and now and save some space.
2761 // However, the concept of EMCP only considers the bytecodes and
2762 // the constant pool entries in the comparison. Other things,
2763 // e.g., the line number table (LNT) or the local variable table
2764 // (LVT) don't count in the comparison. So the new (and EMCP)
2765 // method can have a new LNT that we need so we can't just
2766 // overwrite the new method with the old method.
2767 //
2768 // When this routine is called, we have already attached the new
2769 // methods to the_class so the old methods are effectively
2770 // overwritten. However, if an old method is still executing,
2771 // then the old method cannot be collected until sometime after
2772 // the old method call has returned. So the overwriting of old
2773 // methods by new methods will save us space except for those
2774 // (hopefully few) old methods that are still executing.
2775 //
2776 // A method refers to a ConstMethod* and this presents another
2777 // possible avenue to space savings. The ConstMethod* in the
2778 // new method contains possibly new attributes (LNT, LVT, etc).
2779 // At first glance, it seems possible to save space by replacing
2780 // the ConstMethod* in the old method with the ConstMethod*
2781 // from the new method. The old and new methods would share the
2782 // same ConstMethod* and we would save the space occupied by
2783 // the old ConstMethod*. However, the ConstMethod* contains
2784 // a back reference to the containing method. Sharing the
2785 // ConstMethod* between two methods could lead to confusion in
2786 // the code that uses the back reference. This would lead to
2787 // brittle code that could be broken in non-obvious ways now or
2788 // in the future.
2789 //
2790 // Another possibility is to copy the ConstMethod* from the new
2791 // method to the old method and then overwrite the new method with
2792 // the old method. Since the ConstMethod* contains the bytecodes
2793 // for the method embedded in the oop, this option would change
2794 // the bytecodes out from under any threads executing the old
2795 // method and make the thread's bcp invalid. Since EMCP requires
2796 // that the bytecodes be the same modulo constant pool indices, it
2797 // is straight forward to compute the correct new bcp in the new
2798 // ConstMethod* from the old bcp in the old ConstMethod*. The
2799 // time consuming part would be searching all the frames in all
2800 // of the threads to find all of the calls to the old method.
2801 //
2802 // It looks like we will have to live with the limited savings
2803 // that we get from effectively overwriting the old methods
2804 // when the new methods are attached to the_class.
2805
2806 // track which methods are EMCP for add_previous_version() call
2807 emcp_methods->set_bit(old_index);
2808 (*emcp_method_count_p)++;
2809
2810 // An EMCP method is _not_ obsolete. An obsolete method has a
2811 // different jmethodID than the current method. An EMCP method
2812 // has the same jmethodID as the current method. Having the
2813 // same jmethodID for all EMCP versions of a method allows for
2814 // a consistent view of the EMCP methods regardless of which
2815 // EMCP method you happen to have in hand. For example, a
2816 // breakpoint set in one EMCP method will work for all EMCP
2817 // versions of the method including the current one.
2818 } else {
2819 // mark obsolete methods as such
2820 old_method->set_is_obsolete();
2821 obsolete_count++;
2822
2823 // obsolete methods need a unique idnum
2824 u2 num = InstanceKlass::cast(_the_class_oop)->next_method_idnum();
2825 if (num != ConstMethod::UNSET_IDNUM) {
2826 // u2 old_num = old_method->method_idnum();
2827 old_method->set_method_idnum(num);
2828 // TO DO: attach obsolete annotations to obsolete method's new idnum
2829 }
2830 // With tracing we try not to "yack" too much. The position of
2831 // this trace assumes there are fewer obsolete methods than
2832 // EMCP methods.
2833 RC_TRACE(0x00000100, ("mark %s(%s) as obsolete",
2834 old_method->name()->as_C_string(),
2835 old_method->signature()->as_C_string()));
2836 }
2837 old_method->set_is_old();
2838 }
2839 for (int i = 0; i < _deleted_methods_length; ++i) {
2840 Method* old_method = _deleted_methods[i];
2841
2842 assert(old_method->vtable_index() < 0,
2843 "cannot delete methods with vtable entries");;
2844
2845 // Mark all deleted methods as old and obsolete
2846 old_method->set_is_old();
2847 old_method->set_is_obsolete();
2848 ++obsolete_count;
2849 // With tracing we try not to "yack" too much. The position of
2850 // this trace assumes there are fewer obsolete methods than
2851 // EMCP methods.
2852 RC_TRACE(0x00000100, ("mark deleted %s(%s) as obsolete",
2853 old_method->name()->as_C_string(),
2854 old_method->signature()->as_C_string()));
2855 }
2856 assert((*emcp_method_count_p + obsolete_count) == _old_methods->length(),
2857 "sanity check");
2858 RC_TRACE(0x00000100, ("EMCP_cnt=%d, obsolete_cnt=%d", *emcp_method_count_p,
2859 obsolete_count));
2860 }
2861
2862 // This internal class transfers the native function registration from old methods
2863 // to new methods. It is designed to handle both the simple case of unchanged
2864 // native methods and the complex cases of native method prefixes being added and/or
2865 // removed.
2866 // It expects only to be used during the VM_RedefineClasses op (a safepoint).
2867 //
2868 // This class is used after the new methods have been installed in "the_class".
2869 //
2870 // So, for example, the following must be handled. Where 'm' is a method and
2871 // a number followed by an underscore is a prefix.
2872 //
2873 // Old Name New Name
2874 // Simple transfer to new method m -> m
2875 // Add prefix m -> 1_m
2876 // Remove prefix 1_m -> m
2877 // Simultaneous add of prefixes m -> 3_2_1_m
2878 // Simultaneous removal of prefixes 3_2_1_m -> m
2879 // Simultaneous add and remove 1_m -> 2_m
2880 // Same, caused by prefix removal only 3_2_1_m -> 3_2_m
2881 //
2882 class TransferNativeFunctionRegistration {
2883 private:
2884 instanceKlassHandle the_class;
2885 int prefix_count;
2886 char** prefixes;
2887
2888 // Recursively search the binary tree of possibly prefixed method names.
2889 // Iteration could be used if all agents were well behaved. Full tree walk is
2890 // more resilent to agents not cleaning up intermediate methods.
2891 // Branch at each depth in the binary tree is:
2892 // (1) without the prefix.
2893 // (2) with the prefix.
2894 // where 'prefix' is the prefix at that 'depth' (first prefix, second prefix,...)
2895 Method* search_prefix_name_space(int depth, char* name_str, size_t name_len,
2896 Symbol* signature) {
2897 TempNewSymbol name_symbol = SymbolTable::probe(name_str, (int)name_len);
2898 if (name_symbol != NULL) {
2899 Method* method = the_class()->lookup_method(name_symbol, signature);
2900 if (method != NULL) {
2901 // Even if prefixed, intermediate methods must exist.
2902 if (method->is_native()) {
2903 // Wahoo, we found a (possibly prefixed) version of the method, return it.
2904 return method;
2905 }
2906 if (depth < prefix_count) {
2907 // Try applying further prefixes (other than this one).
2908 method = search_prefix_name_space(depth+1, name_str, name_len, signature);
2909 if (method != NULL) {
2910 return method; // found
2911 }
2912
2913 // Try adding this prefix to the method name and see if it matches
2914 // another method name.
2915 char* prefix = prefixes[depth];
2916 size_t prefix_len = strlen(prefix);
2917 size_t trial_len = name_len + prefix_len;
2918 char* trial_name_str = NEW_RESOURCE_ARRAY(char, trial_len + 1);
2919 strcpy(trial_name_str, prefix);
2920 strcat(trial_name_str, name_str);
2921 method = search_prefix_name_space(depth+1, trial_name_str, trial_len,
2922 signature);
2923 if (method != NULL) {
2924 // If found along this branch, it was prefixed, mark as such
2925 method->set_is_prefixed_native();
2926 return method; // found
2927 }
2928 }
2929 }
2930 }
2931 return NULL; // This whole branch bore nothing
2932 }
2933
2934 // Return the method name with old prefixes stripped away.
2935 char* method_name_without_prefixes(Method* method) {
2936 Symbol* name = method->name();
2937 char* name_str = name->as_utf8();
2938
2939 // Old prefixing may be defunct, strip prefixes, if any.
2940 for (int i = prefix_count-1; i >= 0; i--) {
2941 char* prefix = prefixes[i];
2942 size_t prefix_len = strlen(prefix);
2943 if (strncmp(prefix, name_str, prefix_len) == 0) {
2944 name_str += prefix_len;
2945 }
2946 }
2947 return name_str;
2948 }
2949
2950 // Strip any prefixes off the old native method, then try to find a
2951 // (possibly prefixed) new native that matches it.
2952 Method* strip_and_search_for_new_native(Method* method) {
2953 ResourceMark rm;
2954 char* name_str = method_name_without_prefixes(method);
2955 return search_prefix_name_space(0, name_str, strlen(name_str),
2956 method->signature());
2957 }
2958
2959 public:
2960
2961 // Construct a native method transfer processor for this class.
2962 TransferNativeFunctionRegistration(instanceKlassHandle _the_class) {
2963 assert(SafepointSynchronize::is_at_safepoint(), "sanity check");
2964
2965 the_class = _the_class;
2966 prefixes = JvmtiExport::get_all_native_method_prefixes(&prefix_count);
2967 }
2968
2969 // Attempt to transfer any of the old or deleted methods that are native
2970 void transfer_registrations(Method** old_methods, int methods_length) {
2971 for (int j = 0; j < methods_length; j++) {
2972 Method* old_method = old_methods[j];
2973
2974 if (old_method->is_native() && old_method->has_native_function()) {
2975 Method* new_method = strip_and_search_for_new_native(old_method);
2976 if (new_method != NULL) {
2977 // Actually set the native function in the new method.
2978 // Redefine does not send events (except CFLH), certainly not this
2979 // behind the scenes re-registration.
2980 new_method->set_native_function(old_method->native_function(),
2981 !Method::native_bind_event_is_interesting);
2982 }
2983 }
2984 }
2985 }
2986 };
2987
2988 // Don't lose the association between a native method and its JNI function.
2989 void VM_RedefineClasses::transfer_old_native_function_registrations(instanceKlassHandle the_class) {
2990 TransferNativeFunctionRegistration transfer(the_class);
2991 transfer.transfer_registrations(_deleted_methods, _deleted_methods_length);
2992 transfer.transfer_registrations(_matching_old_methods, _matching_methods_length);
2993 }
2994
2995 // Deoptimize all compiled code that depends on this class.
2996 //
2997 // If the can_redefine_classes capability is obtained in the onload
2998 // phase then the compiler has recorded all dependencies from startup.
2999 // In that case we need only deoptimize and throw away all compiled code
3000 // that depends on the class.
3001 //
3002 // If can_redefine_classes is obtained sometime after the onload
3003 // phase then the dependency information may be incomplete. In that case
3004 // the first call to RedefineClasses causes all compiled code to be
3005 // thrown away. As can_redefine_classes has been obtained then
3006 // all future compilations will record dependencies so second and
3007 // subsequent calls to RedefineClasses need only throw away code
3008 // that depends on the class.
3009 //
3010 void VM_RedefineClasses::flush_dependent_code(instanceKlassHandle k_h, TRAPS) {
3011 assert_locked_or_safepoint(Compile_lock);
3012
3013 // All dependencies have been recorded from startup or this is a second or
3014 // subsequent use of RedefineClasses
3015 if (JvmtiExport::all_dependencies_are_recorded()) {
3016 Universe::flush_evol_dependents_on(k_h);
3017 } else {
3018 CodeCache::mark_all_nmethods_for_deoptimization();
3019
3020 ResourceMark rm(THREAD);
3021 DeoptimizationMarker dm;
3022
3023 // Deoptimize all activations depending on marked nmethods
3024 Deoptimization::deoptimize_dependents();
3025
3026 // Make the dependent methods not entrant (in VM_Deoptimize they are made zombies)
3027 CodeCache::make_marked_nmethods_not_entrant();
3028
3029 // From now on we know that the dependency information is complete
3030 JvmtiExport::set_all_dependencies_are_recorded(true);
3031 }
3032 }
3033
3034 void VM_RedefineClasses::compute_added_deleted_matching_methods() {
3035 Method* old_method;
3036 Method* new_method;
3037
3038 _matching_old_methods = NEW_RESOURCE_ARRAY(Method*, _old_methods->length());
3039 _matching_new_methods = NEW_RESOURCE_ARRAY(Method*, _old_methods->length());
3040 _added_methods = NEW_RESOURCE_ARRAY(Method*, _new_methods->length());
3041 _deleted_methods = NEW_RESOURCE_ARRAY(Method*, _old_methods->length());
3042
3043 _matching_methods_length = 0;
3044 _deleted_methods_length = 0;
3045 _added_methods_length = 0;
3046
3047 int nj = 0;
3048 int oj = 0;
3049 while (true) {
3050 if (oj >= _old_methods->length()) {
3051 if (nj >= _new_methods->length()) {
3052 break; // we've looked at everything, done
3053 }
3054 // New method at the end
3055 new_method = _new_methods->at(nj);
3056 _added_methods[_added_methods_length++] = new_method;
3057 ++nj;
3058 } else if (nj >= _new_methods->length()) {
3059 // Old method, at the end, is deleted
3060 old_method = _old_methods->at(oj);
3061 _deleted_methods[_deleted_methods_length++] = old_method;
3062 ++oj;
3063 } else {
3064 old_method = _old_methods->at(oj);
3065 new_method = _new_methods->at(nj);
3066 if (old_method->name() == new_method->name()) {
3067 if (old_method->signature() == new_method->signature()) {
3068 _matching_old_methods[_matching_methods_length ] = old_method;
3069 _matching_new_methods[_matching_methods_length++] = new_method;
3070 ++nj;
3071 ++oj;
3072 } else {
3073 // added overloaded have already been moved to the end,
3074 // so this is a deleted overloaded method
3075 _deleted_methods[_deleted_methods_length++] = old_method;
3076 ++oj;
3077 }
3078 } else { // names don't match
3079 if (old_method->name()->fast_compare(new_method->name()) > 0) {
3080 // new method
3081 _added_methods[_added_methods_length++] = new_method;
3082 ++nj;
3083 } else {
3084 // deleted method
3085 _deleted_methods[_deleted_methods_length++] = old_method;
3086 ++oj;
3087 }
3088 }
3089 }
3090 }
3091 assert(_matching_methods_length + _deleted_methods_length == _old_methods->length(), "sanity");
3092 assert(_matching_methods_length + _added_methods_length == _new_methods->length(), "sanity");
3093 }
3094
3095
3096
3097 // Install the redefinition of a class:
3098 // - house keeping (flushing breakpoints and caches, deoptimizing
3099 // dependent compiled code)
3100 // - replacing parts in the_class with parts from scratch_class
3101 // - adding a weak reference to track the obsolete but interesting
3102 // parts of the_class
3103 // - adjusting constant pool caches and vtables in other classes
3104 // that refer to methods in the_class. These adjustments use the
3105 // SystemDictionary::classes_do() facility which only allows
3106 // a helper method to be specified. The interesting parameters
3107 // that we would like to pass to the helper method are saved in
3108 // static global fields in the VM operation.
3109 void VM_RedefineClasses::redefine_single_class(jclass the_jclass,
3110 Klass* scratch_class_oop, TRAPS) {
3111
3112 HandleMark hm(THREAD); // make sure handles from this call are freed
3113 RC_TIMER_START(_timer_rsc_phase1);
3114
3115 instanceKlassHandle scratch_class(scratch_class_oop);
3116
3117 oop the_class_mirror = JNIHandles::resolve_non_null(the_jclass);
3118 Klass* the_class_oop = java_lang_Class::as_Klass(the_class_mirror);
3119 instanceKlassHandle the_class = instanceKlassHandle(THREAD, the_class_oop);
3120
3121 // Remove all breakpoints in methods of this class
3122 JvmtiBreakpoints& jvmti_breakpoints = JvmtiCurrentBreakpoints::get_jvmti_breakpoints();
3123 jvmti_breakpoints.clearall_in_class_at_safepoint(the_class_oop);
3124
3125 if (the_class_oop == Universe::reflect_invoke_cache()->klass()) {
3126 // We are redefining java.lang.reflect.Method. Method.invoke() is
3127 // cached and users of the cache care about each active version of
3128 // the method so we have to track this previous version.
3129 // Do this before methods get switched
3130 Universe::reflect_invoke_cache()->add_previous_version(
3131 the_class->method_with_idnum(Universe::reflect_invoke_cache()->method_idnum()));
3132 }
3133
3134 // Deoptimize all compiled code that depends on this class
3135 flush_dependent_code(the_class, THREAD);
3136
3137 _old_methods = the_class->methods();
3138 _new_methods = scratch_class->methods();
3139 _the_class_oop = the_class_oop;
3140 compute_added_deleted_matching_methods();
3141 update_jmethod_ids();
3142
3143 // Attach new constant pool to the original klass. The original
3144 // klass still refers to the old constant pool (for now).
3145 scratch_class->constants()->set_pool_holder(the_class());
3146
3147 #if 0
3148 // In theory, with constant pool merging in place we should be able
3149 // to save space by using the new, merged constant pool in place of
3150 // the old constant pool(s). By "pool(s)" I mean the constant pool in
3151 // the klass version we are replacing now and any constant pool(s) in
3152 // previous versions of klass. Nice theory, doesn't work in practice.
3153 // When this code is enabled, even simple programs throw NullPointer
3154 // exceptions. I'm guessing that this is caused by some constant pool
3155 // cache difference between the new, merged constant pool and the
3156 // constant pool that was just being used by the klass. I'm keeping
3157 // this code around to archive the idea, but the code has to remain
3158 // disabled for now.
3159
3160 // Attach each old method to the new constant pool. This can be
3161 // done here since we are past the bytecode verification and
3162 // constant pool optimization phases.
3163 for (int i = _old_methods->length() - 1; i >= 0; i--) {
3164 Method* method = _old_methods->at(i);
3165 method->set_constants(scratch_class->constants());
3166 }
3167
3168 {
3169 // walk all previous versions of the klass
3170 InstanceKlass *ik = (InstanceKlass *)the_class();
3171 PreviousVersionWalker pvw(ik);
3172 instanceKlassHandle ikh;
3173 do {
3174 ikh = pvw.next_previous_version();
3175 if (!ikh.is_null()) {
3176 ik = ikh();
3177
3178 // attach previous version of klass to the new constant pool
3179 ik->set_constants(scratch_class->constants());
3180
3181 // Attach each method in the previous version of klass to the
3182 // new constant pool
3183 Array<Method*>* prev_methods = ik->methods();
3184 for (int i = prev_methods->length() - 1; i >= 0; i--) {
3185 Method* method = prev_methods->at(i);
3186 method->set_constants(scratch_class->constants());
3187 }
3188 }
3189 } while (!ikh.is_null());
3190 }
3191 #endif
3192
3193 // Replace methods and constantpool
3194 the_class->set_methods(_new_methods);
3195 scratch_class->set_methods(_old_methods); // To prevent potential GCing of the old methods,
3196 // and to be able to undo operation easily.
3197
3198 ConstantPool* old_constants = the_class->constants();
3199 the_class->set_constants(scratch_class->constants());
3200 scratch_class->set_constants(old_constants); // See the previous comment.
3201 #if 0
3202 // We are swapping the guts of "the new class" with the guts of "the
3203 // class". Since the old constant pool has just been attached to "the
3204 // new class", it seems logical to set the pool holder in the old
3205 // constant pool also. However, doing this will change the observable
3206 // class hierarchy for any old methods that are still executing. A
3207 // method can query the identity of its "holder" and this query uses
3208 // the method's constant pool link to find the holder. The change in
3209 // holding class from "the class" to "the new class" can confuse
3210 // things.
3211 //
3212 // Setting the old constant pool's holder will also cause
3213 // verification done during vtable initialization below to fail.
3214 // During vtable initialization, the vtable's class is verified to be
3215 // a subtype of the method's holder. The vtable's class is "the
3216 // class" and the method's holder is gotten from the constant pool
3217 // link in the method itself. For "the class"'s directly implemented
3218 // methods, the method holder is "the class" itself (as gotten from
3219 // the new constant pool). The check works fine in this case. The
3220 // check also works fine for methods inherited from super classes.
3221 //
3222 // Miranda methods are a little more complicated. A miranda method is
3223 // provided by an interface when the class implementing the interface
3224 // does not provide its own method. These interfaces are implemented
3225 // internally as an InstanceKlass. These special instanceKlasses
3226 // share the constant pool of the class that "implements" the
3227 // interface. By sharing the constant pool, the method holder of a
3228 // miranda method is the class that "implements" the interface. In a
3229 // non-redefine situation, the subtype check works fine. However, if
3230 // the old constant pool's pool holder is modified, then the check
3231 // fails because there is no class hierarchy relationship between the
3232 // vtable's class and "the new class".
3233
3234 old_constants->set_pool_holder(scratch_class());
3235 #endif
3236
3237 // track which methods are EMCP for add_previous_version() call below
3238 BitMap emcp_methods(_old_methods->length());
3239 int emcp_method_count = 0;
3240 emcp_methods.clear(); // clears 0..(length() - 1)
3241 check_methods_and_mark_as_obsolete(&emcp_methods, &emcp_method_count);
3242 transfer_old_native_function_registrations(the_class);
3243
3244 // The class file bytes from before any retransformable agents mucked
3245 // with them was cached on the scratch class, move to the_class.
3246 // Note: we still want to do this if nothing needed caching since it
3247 // should get cleared in the_class too.
3248 if (the_class->get_cached_class_file_bytes() == 0) {
3249 // the_class doesn't have a cache yet so copy it
3250 the_class->set_cached_class_file(
3251 scratch_class->get_cached_class_file_bytes(),
3252 scratch_class->get_cached_class_file_len());
3253 }
3254 #ifndef PRODUCT
3255 else {
3256 assert(the_class->get_cached_class_file_bytes() ==
3257 scratch_class->get_cached_class_file_bytes(), "cache ptrs must match");
3258 assert(the_class->get_cached_class_file_len() ==
3259 scratch_class->get_cached_class_file_len(), "cache lens must match");
3260 }
3261 #endif
3262
3263 // Replace inner_classes
3264 Array<u2>* old_inner_classes = the_class->inner_classes();
3265 the_class->set_inner_classes(scratch_class->inner_classes());
3266 scratch_class->set_inner_classes(old_inner_classes);
3267
3268 // Initialize the vtable and interface table after
3269 // methods have been rewritten
3270 {
3271 ResourceMark rm(THREAD);
3272 // no exception should happen here since we explicitly
3273 // do not check loader constraints.
3274 // compare_and_normalize_class_versions has already checked:
3275 // - classloaders unchanged, signatures unchanged
3276 // - all instanceKlasses for redefined classes reused & contents updated
3277 the_class->vtable()->initialize_vtable(false, THREAD);
3278 the_class->itable()->initialize_itable(false, THREAD);
3279 assert(!HAS_PENDING_EXCEPTION || (THREAD->pending_exception()->is_a(SystemDictionary::ThreadDeath_klass())), "redefine exception");
3280 }
3281
3282 // Leave arrays of jmethodIDs and itable index cache unchanged
3283
3284 // Copy the "source file name" attribute from new class version
3285 the_class->set_source_file_name(scratch_class->source_file_name());
3286
3287 // Copy the "source debug extension" attribute from new class version
3288 the_class->set_source_debug_extension(
3289 scratch_class->source_debug_extension(),
3290 scratch_class->source_debug_extension() == NULL ? 0 :
3291 (int)strlen(scratch_class->source_debug_extension()));
3292
3293 // Use of javac -g could be different in the old and the new
3294 if (scratch_class->access_flags().has_localvariable_table() !=
3295 the_class->access_flags().has_localvariable_table()) {
3296
3297 AccessFlags flags = the_class->access_flags();
3298 if (scratch_class->access_flags().has_localvariable_table()) {
3299 flags.set_has_localvariable_table();
3300 } else {
3301 flags.clear_has_localvariable_table();
3302 }
3303 the_class->set_access_flags(flags);
3304 }
3305
3306 // Since there is currently no rewriting of type annotations indexes
3307 // into the CP, we null out type annotations on scratch_class before
3308 // we swap annotations with the_class rather than facing the
3309 // possibility of shipping annotations with broken indexes to
3310 // Java-land.
3311 Annotations* new_annotations = scratch_class->annotations();
3312 if (new_annotations != NULL) {
3313 Annotations* new_type_annotations = new_annotations->type_annotations();
3314 if (new_type_annotations != NULL) {
3315 MetadataFactory::free_metadata(scratch_class->class_loader_data(), new_type_annotations);
3316 new_annotations->set_type_annotations(NULL);
3317 }
3318 }
3319 // Swap annotation fields values
3320 Annotations* old_annotations = the_class->annotations();
3321 the_class->set_annotations(scratch_class->annotations());
3322 scratch_class->set_annotations(old_annotations);
3323
3324 // Replace minor version number of class file
3325 u2 old_minor_version = the_class->minor_version();
3326 the_class->set_minor_version(scratch_class->minor_version());
3327 scratch_class->set_minor_version(old_minor_version);
3328
3329 // Replace major version number of class file
3330 u2 old_major_version = the_class->major_version();
3331 the_class->set_major_version(scratch_class->major_version());
3332 scratch_class->set_major_version(old_major_version);
3333
3334 // Replace CP indexes for class and name+type of enclosing method
3335 u2 old_class_idx = the_class->enclosing_method_class_index();
3336 u2 old_method_idx = the_class->enclosing_method_method_index();
3337 the_class->set_enclosing_method_indices(
3338 scratch_class->enclosing_method_class_index(),
3339 scratch_class->enclosing_method_method_index());
3340 scratch_class->set_enclosing_method_indices(old_class_idx, old_method_idx);
3341
3342 // keep track of previous versions of this class
3343 the_class->add_previous_version(scratch_class, &emcp_methods,
3344 emcp_method_count);
3345
3346 RC_TIMER_STOP(_timer_rsc_phase1);
3347 RC_TIMER_START(_timer_rsc_phase2);
3348
3349 // Adjust constantpool caches and vtables for all classes
3350 // that reference methods of the evolved class.
3351 SystemDictionary::classes_do(adjust_cpool_cache_and_vtable, THREAD);
3352
3353 // Fix Resolution Error table also to remove old constant pools
3354 SystemDictionary::delete_resolution_error(old_constants);
3355
3356 if (the_class->oop_map_cache() != NULL) {
3357 // Flush references to any obsolete methods from the oop map cache
3358 // so that obsolete methods are not pinned.
3359 the_class->oop_map_cache()->flush_obsolete_entries();
3360 }
3361
3362 // increment the classRedefinedCount field in the_class and in any
3363 // direct and indirect subclasses of the_class
3364 increment_class_counter((InstanceKlass *)the_class(), THREAD);
3365
3366 // RC_TRACE macro has an embedded ResourceMark
3367 RC_TRACE_WITH_THREAD(0x00000001, THREAD,
3368 ("redefined name=%s, count=%d (avail_mem=" UINT64_FORMAT "K)",
3369 the_class->external_name(),
3370 java_lang_Class::classRedefinedCount(the_class_mirror),
3371 os::available_memory() >> 10));
3372
3373 RC_TIMER_STOP(_timer_rsc_phase2);
3374 } // end redefine_single_class()
3375
3376
3377 // Increment the classRedefinedCount field in the specific InstanceKlass
3378 // and in all direct and indirect subclasses.
3379 void VM_RedefineClasses::increment_class_counter(InstanceKlass *ik, TRAPS) {
3380 oop class_mirror = ik->java_mirror();
3381 Klass* class_oop = java_lang_Class::as_Klass(class_mirror);
3382 int new_count = java_lang_Class::classRedefinedCount(class_mirror) + 1;
3383 java_lang_Class::set_classRedefinedCount(class_mirror, new_count);
3384
3385 if (class_oop != _the_class_oop) {
3386 // _the_class_oop count is printed at end of redefine_single_class()
3387 RC_TRACE_WITH_THREAD(0x00000008, THREAD,
3388 ("updated count in subclass=%s to %d", ik->external_name(), new_count));
3389 }
3390
3391 for (Klass *subk = ik->subklass(); subk != NULL;
3392 subk = subk->next_sibling()) {
3393 if (subk->oop_is_instance()) {
3394 // Only update instanceKlasses
3395 InstanceKlass *subik = (InstanceKlass*)subk;
3396 // recursively do subclasses of the current subclass
3397 increment_class_counter(subik, THREAD);
3398 }
3399 }
3400 }
3401
3402 void VM_RedefineClasses::check_class(Klass* k_oop,
3403 ClassLoaderData* initiating_loader,
3404 TRAPS) {
3405 Klass *k = k_oop;
3406 if (k->oop_is_instance()) {
3407 HandleMark hm(THREAD);
3408 InstanceKlass *ik = (InstanceKlass *) k;
3409 bool no_old_methods = true; // be optimistic
3410 ResourceMark rm(THREAD);
3411
3412 // a vtable should never contain old or obsolete methods
3413 if (ik->vtable_length() > 0 &&
3414 !ik->vtable()->check_no_old_or_obsolete_entries()) {
3415 if (RC_TRACE_ENABLED(0x00004000)) {
3416 RC_TRACE_WITH_THREAD(0x00004000, THREAD,
3417 ("klassVtable::check_no_old_or_obsolete_entries failure"
3418 " -- OLD or OBSOLETE method found -- class: %s",
3419 ik->signature_name()));
3420 ik->vtable()->dump_vtable();
3421 }
3422 no_old_methods = false;
3423 }
3424
3425 // an itable should never contain old or obsolete methods
3426 if (ik->itable_length() > 0 &&
3427 !ik->itable()->check_no_old_or_obsolete_entries()) {
3428 if (RC_TRACE_ENABLED(0x00004000)) {
3429 RC_TRACE_WITH_THREAD(0x00004000, THREAD,
3430 ("klassItable::check_no_old_or_obsolete_entries failure"
3431 " -- OLD or OBSOLETE method found -- class: %s",
3432 ik->signature_name()));
3433 ik->itable()->dump_itable();
3434 }
3435 no_old_methods = false;
3436 }
3437
3438 // the constant pool cache should never contain old or obsolete methods
3439 if (ik->constants() != NULL &&
3440 ik->constants()->cache() != NULL &&
3441 !ik->constants()->cache()->check_no_old_or_obsolete_entries()) {
3442 if (RC_TRACE_ENABLED(0x00004000)) {
3443 RC_TRACE_WITH_THREAD(0x00004000, THREAD,
3444 ("cp-cache::check_no_old_or_obsolete_entries failure"
3445 " -- OLD or OBSOLETE method found -- class: %s",
3446 ik->signature_name()));
3447 ik->constants()->cache()->dump_cache();
3448 }
3449 no_old_methods = false;
3450 }
3451
3452 if (!no_old_methods) {
3453 if (RC_TRACE_ENABLED(0x00004000)) {
3454 dump_methods();
3455 } else {
3456 tty->print_cr("INFO: use the '-XX:TraceRedefineClasses=16384' option "
3457 "to see more info about the following guarantee() failure.");
3458 }
3459 guarantee(false, "OLD and/or OBSOLETE method(s) found");
3460 }
3461 }
3462 }
3463
3464 void VM_RedefineClasses::dump_methods() {
3465 int j;
3466 RC_TRACE(0x00004000, ("_old_methods --"));
3467 for (j = 0; j < _old_methods->length(); ++j) {
3468 Method* m = _old_methods->at(j);
3469 RC_TRACE_NO_CR(0x00004000, ("%4d (%5d) ", j, m->vtable_index()));
3470 m->access_flags().print_on(tty);
3471 tty->print(" -- ");
3472 m->print_name(tty);
3473 tty->cr();
3474 }
3475 RC_TRACE(0x00004000, ("_new_methods --"));
3476 for (j = 0; j < _new_methods->length(); ++j) {
3477 Method* m = _new_methods->at(j);
3478 RC_TRACE_NO_CR(0x00004000, ("%4d (%5d) ", j, m->vtable_index()));
3479 m->access_flags().print_on(tty);
3480 tty->print(" -- ");
3481 m->print_name(tty);
3482 tty->cr();
3483 }
3484 RC_TRACE(0x00004000, ("_matching_(old/new)_methods --"));
3485 for (j = 0; j < _matching_methods_length; ++j) {
3486 Method* m = _matching_old_methods[j];
3487 RC_TRACE_NO_CR(0x00004000, ("%4d (%5d) ", j, m->vtable_index()));
3488 m->access_flags().print_on(tty);
3489 tty->print(" -- ");
3490 m->print_name(tty);
3491 tty->cr();
3492 m = _matching_new_methods[j];
3493 RC_TRACE_NO_CR(0x00004000, (" (%5d) ", m->vtable_index()));
3494 m->access_flags().print_on(tty);
3495 tty->cr();
3496 }
3497 RC_TRACE(0x00004000, ("_deleted_methods --"));
3498 for (j = 0; j < _deleted_methods_length; ++j) {
3499 Method* m = _deleted_methods[j];
3500 RC_TRACE_NO_CR(0x00004000, ("%4d (%5d) ", j, m->vtable_index()));
3501 m->access_flags().print_on(tty);
3502 tty->print(" -- ");
3503 m->print_name(tty);
3504 tty->cr();
3505 }
3506 RC_TRACE(0x00004000, ("_added_methods --"));
3507 for (j = 0; j < _added_methods_length; ++j) {
3508 Method* m = _added_methods[j];
3509 RC_TRACE_NO_CR(0x00004000, ("%4d (%5d) ", j, m->vtable_index()));
3510 m->access_flags().print_on(tty);
3511 tty->print(" -- ");
3512 m->print_name(tty);
3513 tty->cr();
3514 }
3515 }