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 = find_or_append_indirect_entry(scratch_cp, name_ref_i, merge_cp_p,
289 merge_cp_length_p, THREAD);
290
291 int signature_ref_i = scratch_cp->signature_ref_index_at(scratch_i);
292 int new_signature_ref_i = find_or_append_indirect_entry(scratch_cp, signature_ref_i,
293 merge_cp_p, merge_cp_length_p,
294 THREAD);
295
296 // If the referenced entries already exist in *merge_cp_p, then
297 // both new_name_ref_i and new_signature_ref_i will both be 0.
298 // In that case, all we are appending is the current entry.
299 if (new_name_ref_i != name_ref_i) {
300 RC_TRACE(0x00080000,
301 ("NameAndType entry@%d name_ref_index change: %d to %d",
302 *merge_cp_length_p, name_ref_i, new_name_ref_i));
303 }
304 if (new_signature_ref_i != signature_ref_i) {
305 RC_TRACE(0x00080000,
306 ("NameAndType entry@%d signature_ref_index change: %d to %d",
307 *merge_cp_length_p, signature_ref_i, new_signature_ref_i));
308 }
309
310 (*merge_cp_p)->name_and_type_at_put(*merge_cp_length_p,
311 new_name_ref_i, new_signature_ref_i);
312 if (scratch_i != *merge_cp_length_p) {
313 // The new entry in *merge_cp_p is at a different index than
314 // the new entry in scratch_cp so we need to map the index values.
315 map_index(scratch_cp, scratch_i, *merge_cp_length_p);
316 }
317 (*merge_cp_length_p)++;
318 } break;
319
320 // this is a double-indirect CP entry so it needs special handling
321 case JVM_CONSTANT_Fieldref: // fall through
322 case JVM_CONSTANT_InterfaceMethodref: // fall through
323 case JVM_CONSTANT_Methodref:
324 {
325 int klass_ref_i = scratch_cp->uncached_klass_ref_index_at(scratch_i);
326 int new_klass_ref_i = find_or_append_indirect_entry(scratch_cp, klass_ref_i,
327 merge_cp_p, merge_cp_length_p, THREAD);
328
329 int name_and_type_ref_i = scratch_cp->uncached_name_and_type_ref_index_at(scratch_i);
330 int new_name_and_type_ref_i = find_or_append_indirect_entry(scratch_cp, name_and_type_ref_i,
331 merge_cp_p, merge_cp_length_p, THREAD);
332
333 const char *entry_name;
334 switch (scratch_cp->tag_at(scratch_i).value()) {
335 case JVM_CONSTANT_Fieldref:
336 entry_name = "Fieldref";
337 (*merge_cp_p)->field_at_put(*merge_cp_length_p, new_klass_ref_i,
338 new_name_and_type_ref_i);
339 break;
340 case JVM_CONSTANT_InterfaceMethodref:
341 entry_name = "IFMethodref";
342 (*merge_cp_p)->interface_method_at_put(*merge_cp_length_p,
343 new_klass_ref_i, new_name_and_type_ref_i);
344 break;
345 case JVM_CONSTANT_Methodref:
346 entry_name = "Methodref";
347 (*merge_cp_p)->method_at_put(*merge_cp_length_p, new_klass_ref_i,
348 new_name_and_type_ref_i);
349 break;
350 default:
351 guarantee(false, "bad switch");
352 break;
353 }
354
355 if (klass_ref_i != new_klass_ref_i) {
356 RC_TRACE(0x00080000, ("%s entry@%d class_index changed: %d to %d",
357 entry_name, *merge_cp_length_p, klass_ref_i, new_klass_ref_i));
358 }
359 if (name_and_type_ref_i != new_name_and_type_ref_i) {
360 RC_TRACE(0x00080000,
361 ("%s entry@%d name_and_type_index changed: %d to %d",
362 entry_name, *merge_cp_length_p, name_and_type_ref_i,
363 new_name_and_type_ref_i));
364 }
365
366 if (scratch_i != *merge_cp_length_p) {
367 // The new entry in *merge_cp_p is at a different index than
368 // the new entry in scratch_cp so we need to map the index values.
369 map_index(scratch_cp, scratch_i, *merge_cp_length_p);
370 }
371 (*merge_cp_length_p)++;
372 } break;
373
374 // this is an indirect CP entry so it needs special handling
375 case JVM_CONSTANT_MethodType:
376 {
377 int ref_i = scratch_cp->method_type_index_at(scratch_i);
378 int new_ref_i = find_or_append_indirect_entry(scratch_cp, ref_i, merge_cp_p,
379 merge_cp_length_p, THREAD);
380 if (new_ref_i != ref_i) {
381 RC_TRACE(0x00080000,
382 ("MethodType entry@%d ref_index change: %d to %d",
383 *merge_cp_length_p, ref_i, new_ref_i));
384 }
385 (*merge_cp_p)->method_type_index_at_put(*merge_cp_length_p, new_ref_i);
386 if (scratch_i != *merge_cp_length_p) {
387 // The new entry in *merge_cp_p is at a different index than
388 // the new entry in scratch_cp so we need to map the index values.
389 map_index(scratch_cp, scratch_i, *merge_cp_length_p);
390 }
391 (*merge_cp_length_p)++;
392 } break;
393
394 // this is an indirect CP entry so it needs special handling
395 case JVM_CONSTANT_MethodHandle:
396 {
397 int ref_kind = scratch_cp->method_handle_ref_kind_at(scratch_i);
398 int ref_i = scratch_cp->method_handle_index_at(scratch_i);
399 int new_ref_i = find_or_append_indirect_entry(scratch_cp, ref_i, merge_cp_p,
400 merge_cp_length_p, THREAD);
401 if (new_ref_i != ref_i) {
402 RC_TRACE(0x00080000,
403 ("MethodHandle entry@%d ref_index change: %d to %d",
404 *merge_cp_length_p, ref_i, new_ref_i));
405 }
406 (*merge_cp_p)->method_handle_index_at_put(*merge_cp_length_p, ref_kind, new_ref_i);
407 if (scratch_i != *merge_cp_length_p) {
408 // The new entry in *merge_cp_p is at a different index than
409 // the new entry in scratch_cp so we need to map the index values.
410 map_index(scratch_cp, scratch_i, *merge_cp_length_p);
411 }
412 (*merge_cp_length_p)++;
413 } break;
414
415 // this is an indirect CP entry so it needs special handling
416 case JVM_CONSTANT_InvokeDynamic:
417 {
418 // TBD: cross-checks and possible extra appends into CP and bsm operands
419 // are needed as well. This issue is tracked by a separate bug 8007037.
420 int bss_idx = scratch_cp->invoke_dynamic_bootstrap_specifier_index(scratch_i);
421
422 int ref_i = scratch_cp->invoke_dynamic_name_and_type_ref_index_at(scratch_i);
423 int new_ref_i = find_or_append_indirect_entry(scratch_cp, ref_i, merge_cp_p,
424 merge_cp_length_p, THREAD);
425 if (new_ref_i != ref_i) {
426 RC_TRACE(0x00080000,
427 ("InvokeDynamic entry@%d name_and_type ref_index change: %d to %d",
428 *merge_cp_length_p, ref_i, new_ref_i));
429 }
430
431 (*merge_cp_p)->invoke_dynamic_at_put(*merge_cp_length_p, bss_idx, new_ref_i);
432 if (scratch_i != *merge_cp_length_p) {
433 // The new entry in *merge_cp_p is at a different index than
434 // the new entry in scratch_cp so we need to map the index values.
435 map_index(scratch_cp, scratch_i, *merge_cp_length_p);
436 }
437 (*merge_cp_length_p)++;
438 } break;
439
440 // At this stage, Class or UnresolvedClass could be here, but not
441 // ClassIndex
442 case JVM_CONSTANT_ClassIndex: // fall through
443
444 // Invalid is used as the tag for the second constant pool entry
445 // occupied by JVM_CONSTANT_Double or JVM_CONSTANT_Long. It should
446 // not be seen by itself.
447 case JVM_CONSTANT_Invalid: // fall through
448
449 // At this stage, String could be here, but not StringIndex
450 case JVM_CONSTANT_StringIndex: // fall through
451
452 // At this stage JVM_CONSTANT_UnresolvedClassInError should not be
453 // here
454 case JVM_CONSTANT_UnresolvedClassInError: // fall through
455
456 default:
457 {
458 // leave a breadcrumb
459 jbyte bad_value = scratch_cp->tag_at(scratch_i).value();
460 ShouldNotReachHere();
461 } break;
462 } // end switch tag value
463 } // end append_entry()
464
465
466 int VM_RedefineClasses::find_or_append_indirect_entry(constantPoolHandle scratch_cp,
467 int ref_i, constantPoolHandle *merge_cp_p, int *merge_cp_length_p, TRAPS) {
468
469 int new_ref_i = ref_i;
470 bool match = (ref_i < *merge_cp_length_p) &&
471 scratch_cp->compare_entry_to(ref_i, *merge_cp_p, ref_i, THREAD);
472
473 if (!match) {
474 // forward reference in *merge_cp_p or not a direct match
475 int found_i = scratch_cp->find_matching_entry(ref_i, *merge_cp_p, THREAD);
476 if (found_i != 0) {
477 guarantee(found_i != ref_i, "compare_entry_to() and find_matching_entry() do not agree");
478 // Found a matching entry somewhere else in *merge_cp_p so just need a mapping entry.
479 new_ref_i = found_i;
480 map_index(scratch_cp, ref_i, found_i);
481 } else {
482 // no match found so we have to append this entry to *merge_cp_p
483 append_entry(scratch_cp, ref_i, merge_cp_p, merge_cp_length_p, THREAD);
484 // The above call to append_entry() can only append one entry
485 // so the post call query of *merge_cp_length_p is only for
486 // the sake of consistency.
487 new_ref_i = *merge_cp_length_p - 1;
488 }
489 }
490
491 return new_ref_i;
492 } // end find_or_append_indirect_entry()
493
494
495 void VM_RedefineClasses::swap_all_method_annotations(int i, int j, instanceKlassHandle scratch_class, TRAPS) {
496 AnnotationArray* save;
497
498 Annotations* sca = scratch_class->annotations();
499 if (sca == NULL) return;
500
501 save = sca->get_method_annotations_of(i);
502 sca->set_method_annotations_of(scratch_class, i, sca->get_method_annotations_of(j), CHECK);
503 sca->set_method_annotations_of(scratch_class, j, save, CHECK);
504
505 save = sca->get_method_parameter_annotations_of(i);
506 sca->set_method_parameter_annotations_of(scratch_class, i, sca->get_method_parameter_annotations_of(j), CHECK);
507 sca->set_method_parameter_annotations_of(scratch_class, j, save, CHECK);
508
509 save = sca->get_method_default_annotations_of(i);
510 sca->set_method_default_annotations_of(scratch_class, i, sca->get_method_default_annotations_of(j), CHECK);
511 sca->set_method_default_annotations_of(scratch_class, j, save, CHECK);
512 }
513
514
515 jvmtiError VM_RedefineClasses::compare_and_normalize_class_versions(
516 instanceKlassHandle the_class,
517 instanceKlassHandle scratch_class) {
518 int i;
519
520 // Check superclasses, or rather their names, since superclasses themselves can be
521 // requested to replace.
522 // Check for NULL superclass first since this might be java.lang.Object
523 if (the_class->super() != scratch_class->super() &&
524 (the_class->super() == NULL || scratch_class->super() == NULL ||
525 the_class->super()->name() !=
526 scratch_class->super()->name())) {
527 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_HIERARCHY_CHANGED;
528 }
529
530 // Check if the number, names and order of directly implemented interfaces are the same.
531 // I think in principle we should just check if the sets of names of directly implemented
532 // interfaces are the same, i.e. the order of declaration (which, however, if changed in the
533 // .java file, also changes in .class file) should not matter. However, comparing sets is
534 // technically a bit more difficult, and, more importantly, I am not sure at present that the
535 // order of interfaces does not matter on the implementation level, i.e. that the VM does not
536 // rely on it somewhere.
537 Array<Klass*>* k_interfaces = the_class->local_interfaces();
538 Array<Klass*>* k_new_interfaces = scratch_class->local_interfaces();
539 int n_intfs = k_interfaces->length();
540 if (n_intfs != k_new_interfaces->length()) {
541 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_HIERARCHY_CHANGED;
542 }
543 for (i = 0; i < n_intfs; i++) {
544 if (k_interfaces->at(i)->name() !=
545 k_new_interfaces->at(i)->name()) {
546 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_HIERARCHY_CHANGED;
547 }
548 }
549
550 // Check whether class is in the error init state.
551 if (the_class->is_in_error_state()) {
552 // TBD #5057930: special error code is needed in 1.6
553 return JVMTI_ERROR_INVALID_CLASS;
554 }
555
556 // Check whether class modifiers are the same.
557 jushort old_flags = (jushort) the_class->access_flags().get_flags();
558 jushort new_flags = (jushort) scratch_class->access_flags().get_flags();
559 if (old_flags != new_flags) {
560 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_CLASS_MODIFIERS_CHANGED;
561 }
562
563 // Check if the number, names, types and order of fields declared in these classes
564 // are the same.
565 JavaFieldStream old_fs(the_class);
566 JavaFieldStream new_fs(scratch_class);
567 for (; !old_fs.done() && !new_fs.done(); old_fs.next(), new_fs.next()) {
568 // access
569 old_flags = old_fs.access_flags().as_short();
570 new_flags = new_fs.access_flags().as_short();
571 if ((old_flags ^ new_flags) & JVM_RECOGNIZED_FIELD_MODIFIERS) {
572 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_SCHEMA_CHANGED;
573 }
574 // offset
575 if (old_fs.offset() != new_fs.offset()) {
576 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_SCHEMA_CHANGED;
577 }
578 // name and signature
579 Symbol* name_sym1 = the_class->constants()->symbol_at(old_fs.name_index());
580 Symbol* sig_sym1 = the_class->constants()->symbol_at(old_fs.signature_index());
581 Symbol* name_sym2 = scratch_class->constants()->symbol_at(new_fs.name_index());
582 Symbol* sig_sym2 = scratch_class->constants()->symbol_at(new_fs.signature_index());
583 if (name_sym1 != name_sym2 || sig_sym1 != sig_sym2) {
584 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_SCHEMA_CHANGED;
585 }
586 }
587
588 // If both streams aren't done then we have a differing number of
589 // fields.
590 if (!old_fs.done() || !new_fs.done()) {
591 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_SCHEMA_CHANGED;
592 }
593
594 // Do a parallel walk through the old and new methods. Detect
595 // cases where they match (exist in both), have been added in
596 // the new methods, or have been deleted (exist only in the
597 // old methods). The class file parser places methods in order
598 // by method name, but does not order overloaded methods by
599 // signature. In order to determine what fate befell the methods,
600 // this code places the overloaded new methods that have matching
601 // old methods in the same order as the old methods and places
602 // new overloaded methods at the end of overloaded methods of
603 // that name. The code for this order normalization is adapted
604 // from the algorithm used in InstanceKlass::find_method().
605 // Since we are swapping out of order entries as we find them,
606 // we only have to search forward through the overloaded methods.
607 // Methods which are added and have the same name as an existing
608 // method (but different signature) will be put at the end of
609 // the methods with that name, and the name mismatch code will
610 // handle them.
611 Array<Method*>* k_old_methods(the_class->methods());
612 Array<Method*>* k_new_methods(scratch_class->methods());
613 int n_old_methods = k_old_methods->length();
614 int n_new_methods = k_new_methods->length();
615 Thread* thread = Thread::current();
616
617 int ni = 0;
618 int oi = 0;
619 while (true) {
620 Method* k_old_method;
621 Method* k_new_method;
622 enum { matched, added, deleted, undetermined } method_was = undetermined;
623
624 if (oi >= n_old_methods) {
625 if (ni >= n_new_methods) {
626 break; // we've looked at everything, done
627 }
628 // New method at the end
629 k_new_method = k_new_methods->at(ni);
630 method_was = added;
631 } else if (ni >= n_new_methods) {
632 // Old method, at the end, is deleted
633 k_old_method = k_old_methods->at(oi);
634 method_was = deleted;
635 } else {
636 // There are more methods in both the old and new lists
637 k_old_method = k_old_methods->at(oi);
638 k_new_method = k_new_methods->at(ni);
639 if (k_old_method->name() != k_new_method->name()) {
640 // Methods are sorted by method name, so a mismatch means added
641 // or deleted
642 if (k_old_method->name()->fast_compare(k_new_method->name()) > 0) {
643 method_was = added;
644 } else {
645 method_was = deleted;
646 }
647 } else if (k_old_method->signature() == k_new_method->signature()) {
648 // Both the name and signature match
649 method_was = matched;
650 } else {
651 // The name matches, but the signature doesn't, which means we have to
652 // search forward through the new overloaded methods.
653 int nj; // outside the loop for post-loop check
654 for (nj = ni + 1; nj < n_new_methods; nj++) {
655 Method* m = k_new_methods->at(nj);
656 if (k_old_method->name() != m->name()) {
657 // reached another method name so no more overloaded methods
658 method_was = deleted;
659 break;
660 }
661 if (k_old_method->signature() == m->signature()) {
662 // found a match so swap the methods
663 k_new_methods->at_put(ni, m);
664 k_new_methods->at_put(nj, k_new_method);
665 k_new_method = m;
666 method_was = matched;
667 break;
668 }
669 }
670
671 if (nj >= n_new_methods) {
672 // reached the end without a match; so method was deleted
673 method_was = deleted;
674 }
675 }
676 }
677
678 switch (method_was) {
679 case matched:
680 // methods match, be sure modifiers do too
681 old_flags = (jushort) k_old_method->access_flags().get_flags();
682 new_flags = (jushort) k_new_method->access_flags().get_flags();
683 if ((old_flags ^ new_flags) & ~(JVM_ACC_NATIVE)) {
684 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_MODIFIERS_CHANGED;
685 }
686 {
687 u2 new_num = k_new_method->method_idnum();
688 u2 old_num = k_old_method->method_idnum();
689 if (new_num != old_num) {
690 Method* idnum_owner = scratch_class->method_with_idnum(old_num);
691 if (idnum_owner != NULL) {
692 // There is already a method assigned this idnum -- switch them
693 idnum_owner->set_method_idnum(new_num);
694 }
695 k_new_method->set_method_idnum(old_num);
696 swap_all_method_annotations(old_num, new_num, scratch_class, thread);
697 if (thread->has_pending_exception()) {
698 return JVMTI_ERROR_OUT_OF_MEMORY;
699 }
700 }
701 }
702 RC_TRACE(0x00008000, ("Method matched: new: %s [%d] == old: %s [%d]",
703 k_new_method->name_and_sig_as_C_string(), ni,
704 k_old_method->name_and_sig_as_C_string(), oi));
705 // advance to next pair of methods
706 ++oi;
707 ++ni;
708 break;
709 case added:
710 // method added, see if it is OK
711 new_flags = (jushort) k_new_method->access_flags().get_flags();
712 if ((new_flags & JVM_ACC_PRIVATE) == 0
713 // hack: private should be treated as final, but alas
714 || (new_flags & (JVM_ACC_FINAL|JVM_ACC_STATIC)) == 0
715 ) {
716 // new methods must be private
717 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_ADDED;
718 }
719 {
720 u2 num = the_class->next_method_idnum();
721 if (num == ConstMethod::UNSET_IDNUM) {
722 // cannot add any more methods
723 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_ADDED;
724 }
725 u2 new_num = k_new_method->method_idnum();
726 Method* idnum_owner = scratch_class->method_with_idnum(num);
727 if (idnum_owner != NULL) {
728 // There is already a method assigned this idnum -- switch them
729 idnum_owner->set_method_idnum(new_num);
730 }
731 k_new_method->set_method_idnum(num);
732 swap_all_method_annotations(new_num, num, scratch_class, thread);
733 if (thread->has_pending_exception()) {
734 return JVMTI_ERROR_OUT_OF_MEMORY;
735 }
736 }
737 RC_TRACE(0x00008000, ("Method added: new: %s [%d]",
738 k_new_method->name_and_sig_as_C_string(), ni));
739 ++ni; // advance to next new method
740 break;
741 case deleted:
742 // method deleted, see if it is OK
743 old_flags = (jushort) k_old_method->access_flags().get_flags();
744 if ((old_flags & JVM_ACC_PRIVATE) == 0
745 // hack: private should be treated as final, but alas
746 || (old_flags & (JVM_ACC_FINAL|JVM_ACC_STATIC)) == 0
747 ) {
748 // deleted methods must be private
749 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_DELETED;
750 }
751 RC_TRACE(0x00008000, ("Method deleted: old: %s [%d]",
752 k_old_method->name_and_sig_as_C_string(), oi));
753 ++oi; // advance to next old method
754 break;
755 default:
756 ShouldNotReachHere();
757 }
758 }
759
760 return JVMTI_ERROR_NONE;
761 }
762
763
764 // Find new constant pool index value for old constant pool index value
765 // by seaching the index map. Returns zero (0) if there is no mapped
766 // value for the old constant pool index.
767 int VM_RedefineClasses::find_new_index(int old_index) {
768 if (_index_map_count == 0) {
769 // map is empty so nothing can be found
770 return 0;
771 }
772
773 if (old_index < 1 || old_index >= _index_map_p->length()) {
774 // The old_index is out of range so it is not mapped. This should
775 // not happen in regular constant pool merging use, but it can
776 // happen if a corrupt annotation is processed.
777 return 0;
778 }
779
780 int value = _index_map_p->at(old_index);
781 if (value == -1) {
782 // the old_index is not mapped
783 return 0;
784 }
785
786 return value;
787 } // end find_new_index()
788
789
790 // Returns true if the current mismatch is due to a resolved/unresolved
791 // class pair. Otherwise, returns false.
792 bool VM_RedefineClasses::is_unresolved_class_mismatch(constantPoolHandle cp1,
793 int index1, constantPoolHandle cp2, int index2) {
794
795 jbyte t1 = cp1->tag_at(index1).value();
796 if (t1 != JVM_CONSTANT_Class && t1 != JVM_CONSTANT_UnresolvedClass) {
797 return false; // wrong entry type; not our special case
798 }
799
800 jbyte t2 = cp2->tag_at(index2).value();
801 if (t2 != JVM_CONSTANT_Class && t2 != JVM_CONSTANT_UnresolvedClass) {
802 return false; // wrong entry type; not our special case
803 }
804
805 if (t1 == t2) {
806 return false; // not a mismatch; not our special case
807 }
808
809 char *s1 = cp1->klass_name_at(index1)->as_C_string();
810 char *s2 = cp2->klass_name_at(index2)->as_C_string();
811 if (strcmp(s1, s2) != 0) {
812 return false; // strings don't match; not our special case
813 }
814
815 return true; // made it through the gauntlet; this is our special case
816 } // end is_unresolved_class_mismatch()
817
818
819 jvmtiError VM_RedefineClasses::load_new_class_versions(TRAPS) {
820
821 // For consistency allocate memory using os::malloc wrapper.
822 _scratch_classes = (Klass**)
823 os::malloc(sizeof(Klass*) * _class_count, mtClass);
824 if (_scratch_classes == NULL) {
825 return JVMTI_ERROR_OUT_OF_MEMORY;
826 }
827 // Zero initialize the _scratch_classes array.
828 for (int i = 0; i < _class_count; i++) {
829 _scratch_classes[i] = NULL;
830 }
831
832 ResourceMark rm(THREAD);
833
834 JvmtiThreadState *state = JvmtiThreadState::state_for(JavaThread::current());
835 // state can only be NULL if the current thread is exiting which
836 // should not happen since we're trying to do a RedefineClasses
837 guarantee(state != NULL, "exiting thread calling load_new_class_versions");
838 for (int i = 0; i < _class_count; i++) {
839 // Create HandleMark so that any handles created while loading new class
840 // versions are deleted. Constant pools are deallocated while merging
841 // constant pools
842 HandleMark hm(THREAD);
843
844 oop mirror = JNIHandles::resolve_non_null(_class_defs[i].klass);
845 // classes for primitives cannot be redefined
846 if (!is_modifiable_class(mirror)) {
847 return JVMTI_ERROR_UNMODIFIABLE_CLASS;
848 }
849 Klass* the_class_oop = java_lang_Class::as_Klass(mirror);
850 instanceKlassHandle the_class = instanceKlassHandle(THREAD, the_class_oop);
851 Symbol* the_class_sym = the_class->name();
852
853 // RC_TRACE_WITH_THREAD macro has an embedded ResourceMark
854 RC_TRACE_WITH_THREAD(0x00000001, THREAD,
855 ("loading name=%s kind=%d (avail_mem=" UINT64_FORMAT "K)",
856 the_class->external_name(), _class_load_kind,
857 os::available_memory() >> 10));
858
859 ClassFileStream st((u1*) _class_defs[i].class_bytes,
860 _class_defs[i].class_byte_count, (char *)"__VM_RedefineClasses__");
861
862 // Parse the stream.
863 Handle the_class_loader(THREAD, the_class->class_loader());
864 Handle protection_domain(THREAD, the_class->protection_domain());
865 // Set redefined class handle in JvmtiThreadState class.
866 // This redefined class is sent to agent event handler for class file
867 // load hook event.
868 state->set_class_being_redefined(&the_class, _class_load_kind);
869
870 Klass* k = SystemDictionary::parse_stream(the_class_sym,
871 the_class_loader,
872 protection_domain,
873 &st,
874 THREAD);
875 // Clear class_being_redefined just to be sure.
876 state->clear_class_being_redefined();
877
878 // TODO: if this is retransform, and nothing changed we can skip it
879
880 instanceKlassHandle scratch_class (THREAD, k);
881
882 // Need to clean up allocated InstanceKlass if there's an error so assign
883 // the result here. Caller deallocates all the scratch classes in case of
884 // an error.
885 _scratch_classes[i] = k;
886
887 if (HAS_PENDING_EXCEPTION) {
888 Symbol* ex_name = PENDING_EXCEPTION->klass()->name();
889 // RC_TRACE_WITH_THREAD macro has an embedded ResourceMark
890 RC_TRACE_WITH_THREAD(0x00000002, THREAD, ("parse_stream exception: '%s'",
891 ex_name->as_C_string()));
892 CLEAR_PENDING_EXCEPTION;
893
894 if (ex_name == vmSymbols::java_lang_UnsupportedClassVersionError()) {
895 return JVMTI_ERROR_UNSUPPORTED_VERSION;
896 } else if (ex_name == vmSymbols::java_lang_ClassFormatError()) {
897 return JVMTI_ERROR_INVALID_CLASS_FORMAT;
898 } else if (ex_name == vmSymbols::java_lang_ClassCircularityError()) {
899 return JVMTI_ERROR_CIRCULAR_CLASS_DEFINITION;
900 } else if (ex_name == vmSymbols::java_lang_NoClassDefFoundError()) {
901 // The message will be "XXX (wrong name: YYY)"
902 return JVMTI_ERROR_NAMES_DONT_MATCH;
903 } else if (ex_name == vmSymbols::java_lang_OutOfMemoryError()) {
904 return JVMTI_ERROR_OUT_OF_MEMORY;
905 } else { // Just in case more exceptions can be thrown..
906 return JVMTI_ERROR_FAILS_VERIFICATION;
907 }
908 }
909
910 // Ensure class is linked before redefine
911 if (!the_class->is_linked()) {
912 the_class->link_class(THREAD);
913 if (HAS_PENDING_EXCEPTION) {
914 Symbol* ex_name = PENDING_EXCEPTION->klass()->name();
915 // RC_TRACE_WITH_THREAD macro has an embedded ResourceMark
916 RC_TRACE_WITH_THREAD(0x00000002, THREAD, ("link_class exception: '%s'",
917 ex_name->as_C_string()));
918 CLEAR_PENDING_EXCEPTION;
919 if (ex_name == vmSymbols::java_lang_OutOfMemoryError()) {
920 return JVMTI_ERROR_OUT_OF_MEMORY;
921 } else {
922 return JVMTI_ERROR_INTERNAL;
923 }
924 }
925 }
926
927 // Do the validity checks in compare_and_normalize_class_versions()
928 // before verifying the byte codes. By doing these checks first, we
929 // limit the number of functions that require redirection from
930 // the_class to scratch_class. In particular, we don't have to
931 // modify JNI GetSuperclass() and thus won't change its performance.
932 jvmtiError res = compare_and_normalize_class_versions(the_class,
933 scratch_class);
934 if (res != JVMTI_ERROR_NONE) {
935 return res;
936 }
937
938 // verify what the caller passed us
939 {
940 // The bug 6214132 caused the verification to fail.
941 // Information about the_class and scratch_class is temporarily
942 // recorded into jvmtiThreadState. This data is used to redirect
943 // the_class to scratch_class in the JVM_* functions called by the
944 // verifier. Please, refer to jvmtiThreadState.hpp for the detailed
945 // description.
946 RedefineVerifyMark rvm(&the_class, &scratch_class, state);
947 Verifier::verify(
948 scratch_class, Verifier::ThrowException, true, THREAD);
949 }
950
951 if (HAS_PENDING_EXCEPTION) {
952 Symbol* ex_name = PENDING_EXCEPTION->klass()->name();
953 // RC_TRACE_WITH_THREAD macro has an embedded ResourceMark
954 RC_TRACE_WITH_THREAD(0x00000002, THREAD,
955 ("verify_byte_codes exception: '%s'", ex_name->as_C_string()));
956 CLEAR_PENDING_EXCEPTION;
957 if (ex_name == vmSymbols::java_lang_OutOfMemoryError()) {
958 return JVMTI_ERROR_OUT_OF_MEMORY;
959 } else {
960 // tell the caller the bytecodes are bad
961 return JVMTI_ERROR_FAILS_VERIFICATION;
962 }
963 }
964
965 res = merge_cp_and_rewrite(the_class, scratch_class, THREAD);
966 if (res != JVMTI_ERROR_NONE) {
967 return res;
968 }
969
970 if (VerifyMergedCPBytecodes) {
971 // verify what we have done during constant pool merging
972 {
973 RedefineVerifyMark rvm(&the_class, &scratch_class, state);
974 Verifier::verify(scratch_class, Verifier::ThrowException, true, THREAD);
975 }
976
977 if (HAS_PENDING_EXCEPTION) {
978 Symbol* ex_name = PENDING_EXCEPTION->klass()->name();
979 // RC_TRACE_WITH_THREAD macro has an embedded ResourceMark
980 RC_TRACE_WITH_THREAD(0x00000002, THREAD,
981 ("verify_byte_codes post merge-CP exception: '%s'",
982 ex_name->as_C_string()));
983 CLEAR_PENDING_EXCEPTION;
984 if (ex_name == vmSymbols::java_lang_OutOfMemoryError()) {
985 return JVMTI_ERROR_OUT_OF_MEMORY;
986 } else {
987 // tell the caller that constant pool merging screwed up
988 return JVMTI_ERROR_INTERNAL;
989 }
990 }
991 }
992
993 Rewriter::rewrite(scratch_class, THREAD);
994 if (!HAS_PENDING_EXCEPTION) {
995 scratch_class->link_methods(THREAD);
996 }
997 if (HAS_PENDING_EXCEPTION) {
998 Symbol* ex_name = PENDING_EXCEPTION->klass()->name();
999 CLEAR_PENDING_EXCEPTION;
1000 if (ex_name == vmSymbols::java_lang_OutOfMemoryError()) {
1001 return JVMTI_ERROR_OUT_OF_MEMORY;
1002 } else {
1003 return JVMTI_ERROR_INTERNAL;
1004 }
1005 }
1006
1007 // RC_TRACE_WITH_THREAD macro has an embedded ResourceMark
1008 RC_TRACE_WITH_THREAD(0x00000001, THREAD,
1009 ("loaded name=%s (avail_mem=" UINT64_FORMAT "K)",
1010 the_class->external_name(), os::available_memory() >> 10));
1011 }
1012
1013 return JVMTI_ERROR_NONE;
1014 }
1015
1016
1017 // Map old_index to new_index as needed. scratch_cp is only needed
1018 // for RC_TRACE() calls.
1019 void VM_RedefineClasses::map_index(constantPoolHandle scratch_cp,
1020 int old_index, int new_index) {
1021 if (find_new_index(old_index) != 0) {
1022 // old_index is already mapped
1023 return;
1024 }
1025
1026 if (old_index == new_index) {
1027 // no mapping is needed
1028 return;
1029 }
1030
1031 _index_map_p->at_put(old_index, new_index);
1032 _index_map_count++;
1033
1034 RC_TRACE(0x00040000, ("mapped tag %d at index %d to %d",
1035 scratch_cp->tag_at(old_index).value(), old_index, new_index));
1036 } // end map_index()
1037
1038
1039 // Merge old_cp and scratch_cp and return the results of the merge via
1040 // merge_cp_p. The number of entries in *merge_cp_p is returned via
1041 // merge_cp_length_p. The entries in old_cp occupy the same locations
1042 // in *merge_cp_p. Also creates a map of indices from entries in
1043 // scratch_cp to the corresponding entry in *merge_cp_p. Index map
1044 // entries are only created for entries in scratch_cp that occupy a
1045 // different location in *merged_cp_p.
1046 bool VM_RedefineClasses::merge_constant_pools(constantPoolHandle old_cp,
1047 constantPoolHandle scratch_cp, constantPoolHandle *merge_cp_p,
1048 int *merge_cp_length_p, TRAPS) {
1049
1050 if (merge_cp_p == NULL) {
1051 assert(false, "caller must provide scratch constantPool");
1052 return false; // robustness
1053 }
1054 if (merge_cp_length_p == NULL) {
1055 assert(false, "caller must provide scratch CP length");
1056 return false; // robustness
1057 }
1058 // Worst case we need old_cp->length() + scratch_cp()->length(),
1059 // but the caller might be smart so make sure we have at least
1060 // the minimum.
1061 if ((*merge_cp_p)->length() < old_cp->length()) {
1062 assert(false, "merge area too small");
1063 return false; // robustness
1064 }
1065
1066 RC_TRACE_WITH_THREAD(0x00010000, THREAD,
1067 ("old_cp_len=%d, scratch_cp_len=%d", old_cp->length(),
1068 scratch_cp->length()));
1069
1070 {
1071 // Pass 0:
1072 // The old_cp is copied to *merge_cp_p; this means that any code
1073 // using old_cp does not have to change. This work looks like a
1074 // perfect fit for ConstantPool*::copy_cp_to(), but we need to
1075 // handle one special case:
1076 // - revert JVM_CONSTANT_Class to JVM_CONSTANT_UnresolvedClass
1077 // This will make verification happy.
1078
1079 int old_i; // index into old_cp
1080
1081 // index zero (0) is not used in constantPools
1082 for (old_i = 1; old_i < old_cp->length(); old_i++) {
1083 // leave debugging crumb
1084 jbyte old_tag = old_cp->tag_at(old_i).value();
1085 switch (old_tag) {
1086 case JVM_CONSTANT_Class:
1087 case JVM_CONSTANT_UnresolvedClass:
1088 // revert the copy to JVM_CONSTANT_UnresolvedClass
1089 // May be resolving while calling this so do the same for
1090 // JVM_CONSTANT_UnresolvedClass (klass_name_at() deals with transition)
1091 (*merge_cp_p)->unresolved_klass_at_put(old_i,
1092 old_cp->klass_name_at(old_i));
1093 break;
1094
1095 case JVM_CONSTANT_Double:
1096 case JVM_CONSTANT_Long:
1097 // just copy the entry to *merge_cp_p, but double and long take
1098 // two constant pool entries
1099 ConstantPool::copy_entry_to(old_cp, old_i, *merge_cp_p, old_i, CHECK_0);
1100 old_i++;
1101 break;
1102
1103 default:
1104 // just copy the entry to *merge_cp_p
1105 ConstantPool::copy_entry_to(old_cp, old_i, *merge_cp_p, old_i, CHECK_0);
1106 break;
1107 }
1108 } // end for each old_cp entry
1109
1110 ConstantPool::copy_operands(old_cp, *merge_cp_p, CHECK_0);
1111
1112 // We don't need to sanity check that *merge_cp_length_p is within
1113 // *merge_cp_p bounds since we have the minimum on-entry check above.
1114 (*merge_cp_length_p) = old_i;
1115 }
1116
1117 // merge_cp_len should be the same as old_cp->length() at this point
1118 // so this trace message is really a "warm-and-breathing" message.
1119 RC_TRACE_WITH_THREAD(0x00020000, THREAD,
1120 ("after pass 0: merge_cp_len=%d", *merge_cp_length_p));
1121
1122 int scratch_i; // index into scratch_cp
1123 {
1124 // Pass 1a:
1125 // Compare scratch_cp entries to the old_cp entries that we have
1126 // already copied to *merge_cp_p. In this pass, we are eliminating
1127 // exact duplicates (matching entry at same index) so we only
1128 // compare entries in the common indice range.
1129 int increment = 1;
1130 int pass1a_length = MIN2(old_cp->length(), scratch_cp->length());
1131 for (scratch_i = 1; scratch_i < pass1a_length; scratch_i += increment) {
1132 switch (scratch_cp->tag_at(scratch_i).value()) {
1133 case JVM_CONSTANT_Double:
1134 case JVM_CONSTANT_Long:
1135 // double and long take two constant pool entries
1136 increment = 2;
1137 break;
1138
1139 default:
1140 increment = 1;
1141 break;
1142 }
1143
1144 bool match = scratch_cp->compare_entry_to(scratch_i, *merge_cp_p,
1145 scratch_i, CHECK_0);
1146 if (match) {
1147 // found a match at the same index so nothing more to do
1148 continue;
1149 } else if (is_unresolved_class_mismatch(scratch_cp, scratch_i,
1150 *merge_cp_p, scratch_i)) {
1151 // The mismatch in compare_entry_to() above is because of a
1152 // resolved versus unresolved class entry at the same index
1153 // with the same string value. Since Pass 0 reverted any
1154 // class entries to unresolved class entries in *merge_cp_p,
1155 // we go with the unresolved class entry.
1156 continue;
1157 }
1158
1159 int found_i = scratch_cp->find_matching_entry(scratch_i, *merge_cp_p,
1160 CHECK_0);
1161 if (found_i != 0) {
1162 guarantee(found_i != scratch_i,
1163 "compare_entry_to() and find_matching_entry() do not agree");
1164
1165 // Found a matching entry somewhere else in *merge_cp_p so
1166 // just need a mapping entry.
1167 map_index(scratch_cp, scratch_i, found_i);
1168 continue;
1169 }
1170
1171 // The find_matching_entry() call above could fail to find a match
1172 // due to a resolved versus unresolved class or string entry situation
1173 // like we solved above with the is_unresolved_*_mismatch() calls.
1174 // However, we would have to call is_unresolved_*_mismatch() over
1175 // all of *merge_cp_p (potentially) and that doesn't seem to be
1176 // worth the time.
1177
1178 // No match found so we have to append this entry and any unique
1179 // referenced entries to *merge_cp_p.
1180 append_entry(scratch_cp, scratch_i, merge_cp_p, merge_cp_length_p,
1181 CHECK_0);
1182 }
1183 }
1184
1185 RC_TRACE_WITH_THREAD(0x00020000, THREAD,
1186 ("after pass 1a: merge_cp_len=%d, scratch_i=%d, index_map_len=%d",
1187 *merge_cp_length_p, scratch_i, _index_map_count));
1188
1189 if (scratch_i < scratch_cp->length()) {
1190 // Pass 1b:
1191 // old_cp is smaller than scratch_cp so there are entries in
1192 // scratch_cp that we have not yet processed. We take care of
1193 // those now.
1194 int increment = 1;
1195 for (; scratch_i < scratch_cp->length(); scratch_i += increment) {
1196 switch (scratch_cp->tag_at(scratch_i).value()) {
1197 case JVM_CONSTANT_Double:
1198 case JVM_CONSTANT_Long:
1199 // double and long take two constant pool entries
1200 increment = 2;
1201 break;
1202
1203 default:
1204 increment = 1;
1205 break;
1206 }
1207
1208 int found_i =
1209 scratch_cp->find_matching_entry(scratch_i, *merge_cp_p, CHECK_0);
1210 if (found_i != 0) {
1211 // Found a matching entry somewhere else in *merge_cp_p so
1212 // just need a mapping entry.
1213 map_index(scratch_cp, scratch_i, found_i);
1214 continue;
1215 }
1216
1217 // No match found so we have to append this entry and any unique
1218 // referenced entries to *merge_cp_p.
1219 append_entry(scratch_cp, scratch_i, merge_cp_p, merge_cp_length_p,
1220 CHECK_0);
1221 }
1222
1223 RC_TRACE_WITH_THREAD(0x00020000, THREAD,
1224 ("after pass 1b: merge_cp_len=%d, scratch_i=%d, index_map_len=%d",
1225 *merge_cp_length_p, scratch_i, _index_map_count));
1226 }
1227
1228 return true;
1229 } // end merge_constant_pools()
1230
1231
1232 // Scoped object to clean up the constant pool(s) created for merging
1233 class MergeCPCleaner {
1234 ClassLoaderData* _loader_data;
1235 ConstantPool* _cp;
1236 ConstantPool* _scratch_cp;
1237 public:
1238 MergeCPCleaner(ClassLoaderData* loader_data, ConstantPool* merge_cp) :
1239 _loader_data(loader_data), _cp(merge_cp), _scratch_cp(NULL) {}
1240 ~MergeCPCleaner() {
1241 _loader_data->add_to_deallocate_list(_cp);
1242 if (_scratch_cp != NULL) {
1243 _loader_data->add_to_deallocate_list(_scratch_cp);
1244 }
1245 }
1246 void add_scratch_cp(ConstantPool* scratch_cp) { _scratch_cp = scratch_cp; }
1247 };
1248
1249 // Merge constant pools between the_class and scratch_class and
1250 // potentially rewrite bytecodes in scratch_class to use the merged
1251 // constant pool.
1252 jvmtiError VM_RedefineClasses::merge_cp_and_rewrite(
1253 instanceKlassHandle the_class, instanceKlassHandle scratch_class,
1254 TRAPS) {
1255 // worst case merged constant pool length is old and new combined
1256 int merge_cp_length = the_class->constants()->length()
1257 + scratch_class->constants()->length();
1258
1259 // Constant pools are not easily reused so we allocate a new one
1260 // each time.
1261 // merge_cp is created unsafe for concurrent GC processing. It
1262 // should be marked safe before discarding it. Even though
1263 // garbage, if it crosses a card boundary, it may be scanned
1264 // in order to find the start of the first complete object on the card.
1265 ClassLoaderData* loader_data = the_class->class_loader_data();
1266 ConstantPool* merge_cp_oop =
1267 ConstantPool::allocate(loader_data,
1268 merge_cp_length,
1269 THREAD);
1270 MergeCPCleaner cp_cleaner(loader_data, merge_cp_oop);
1271
1272 HandleMark hm(THREAD); // make sure handles are cleared before
1273 // MergeCPCleaner clears out merge_cp_oop
1274 constantPoolHandle merge_cp(THREAD, merge_cp_oop);
1275
1276 // Get constants() from the old class because it could have been rewritten
1277 // while we were at a safepoint allocating a new constant pool.
1278 constantPoolHandle old_cp(THREAD, the_class->constants());
1279 constantPoolHandle scratch_cp(THREAD, scratch_class->constants());
1280
1281 // If the length changed, the class was redefined out from under us. Return
1282 // an error.
1283 if (merge_cp_length != the_class->constants()->length()
1284 + scratch_class->constants()->length()) {
1285 return JVMTI_ERROR_INTERNAL;
1286 }
1287
1288 // Update the version number of the constant pool
1289 merge_cp->increment_and_save_version(old_cp->version());
1290
1291 ResourceMark rm(THREAD);
1292 _index_map_count = 0;
1293 _index_map_p = new intArray(scratch_cp->length(), -1);
1294
1295 // reference to the cp holder is needed for copy_operands()
1296 merge_cp->set_pool_holder(scratch_class());
1297 bool result = merge_constant_pools(old_cp, scratch_cp, &merge_cp,
1298 &merge_cp_length, THREAD);
1299 merge_cp->set_pool_holder(NULL);
1300
1301 if (!result) {
1302 // The merge can fail due to memory allocation failure or due
1303 // to robustness checks.
1304 return JVMTI_ERROR_INTERNAL;
1305 }
1306
1307 RC_TRACE_WITH_THREAD(0x00010000, THREAD,
1308 ("merge_cp_len=%d, index_map_len=%d", merge_cp_length, _index_map_count));
1309
1310 if (_index_map_count == 0) {
1311 // there is nothing to map between the new and merged constant pools
1312
1313 if (old_cp->length() == scratch_cp->length()) {
1314 // The old and new constant pools are the same length and the
1315 // index map is empty. This means that the three constant pools
1316 // are equivalent (but not the same). Unfortunately, the new
1317 // constant pool has not gone through link resolution nor have
1318 // the new class bytecodes gone through constant pool cache
1319 // rewriting so we can't use the old constant pool with the new
1320 // class.
1321
1322 // toss the merged constant pool at return
1323 } else if (old_cp->length() < scratch_cp->length()) {
1324 // The old constant pool has fewer entries than the new constant
1325 // pool and the index map is empty. This means the new constant
1326 // pool is a superset of the old constant pool. However, the old
1327 // class bytecodes have already gone through constant pool cache
1328 // rewriting so we can't use the new constant pool with the old
1329 // class.
1330
1331 // toss the merged constant pool at return
1332 } else {
1333 // The old constant pool has more entries than the new constant
1334 // pool and the index map is empty. This means that both the old
1335 // and merged constant pools are supersets of the new constant
1336 // pool.
1337
1338 // Replace the new constant pool with a shrunken copy of the
1339 // merged constant pool
1340 set_new_constant_pool(loader_data, scratch_class, merge_cp, merge_cp_length, THREAD);
1341 // The new constant pool replaces scratch_cp so have cleaner clean it up.
1342 // It can't be cleaned up while there are handles to it.
1343 cp_cleaner.add_scratch_cp(scratch_cp());
1344 }
1345 } else {
1346 if (RC_TRACE_ENABLED(0x00040000)) {
1347 // don't want to loop unless we are tracing
1348 int count = 0;
1349 for (int i = 1; i < _index_map_p->length(); i++) {
1350 int value = _index_map_p->at(i);
1351
1352 if (value != -1) {
1353 RC_TRACE_WITH_THREAD(0x00040000, THREAD,
1354 ("index_map[%d]: old=%d new=%d", count, i, value));
1355 count++;
1356 }
1357 }
1358 }
1359
1360 // We have entries mapped between the new and merged constant pools
1361 // so we have to rewrite some constant pool references.
1362 if (!rewrite_cp_refs(scratch_class, THREAD)) {
1363 return JVMTI_ERROR_INTERNAL;
1364 }
1365
1366 // Replace the new constant pool with a shrunken copy of the
1367 // merged constant pool so now the rewritten bytecodes have
1368 // valid references; the previous new constant pool will get
1369 // GCed.
1370 set_new_constant_pool(loader_data, scratch_class, merge_cp, merge_cp_length, THREAD);
1371 // The new constant pool replaces scratch_cp so have cleaner clean it up.
1372 // It can't be cleaned up while there are handles to it.
1373 cp_cleaner.add_scratch_cp(scratch_cp());
1374 }
1375
1376 return JVMTI_ERROR_NONE;
1377 } // end merge_cp_and_rewrite()
1378
1379
1380 // Rewrite constant pool references in klass scratch_class.
1381 bool VM_RedefineClasses::rewrite_cp_refs(instanceKlassHandle scratch_class,
1382 TRAPS) {
1383
1384 // rewrite constant pool references in the methods:
1385 if (!rewrite_cp_refs_in_methods(scratch_class, THREAD)) {
1386 // propagate failure back to caller
1387 return false;
1388 }
1389
1390 // rewrite constant pool references in the class_annotations:
1391 if (!rewrite_cp_refs_in_class_annotations(scratch_class, THREAD)) {
1392 // propagate failure back to caller
1393 return false;
1394 }
1395
1396 // rewrite constant pool references in the fields_annotations:
1397 if (!rewrite_cp_refs_in_fields_annotations(scratch_class, THREAD)) {
1398 // propagate failure back to caller
1399 return false;
1400 }
1401
1402 // rewrite constant pool references in the methods_annotations:
1403 if (!rewrite_cp_refs_in_methods_annotations(scratch_class, THREAD)) {
1404 // propagate failure back to caller
1405 return false;
1406 }
1407
1408 // rewrite constant pool references in the methods_parameter_annotations:
1409 if (!rewrite_cp_refs_in_methods_parameter_annotations(scratch_class,
1410 THREAD)) {
1411 // propagate failure back to caller
1412 return false;
1413 }
1414
1415 // rewrite constant pool references in the methods_default_annotations:
1416 if (!rewrite_cp_refs_in_methods_default_annotations(scratch_class,
1417 THREAD)) {
1418 // propagate failure back to caller
1419 return false;
1420 }
1421
1422 return true;
1423 } // end rewrite_cp_refs()
1424
1425
1426 // Rewrite constant pool references in the methods.
1427 bool VM_RedefineClasses::rewrite_cp_refs_in_methods(
1428 instanceKlassHandle scratch_class, TRAPS) {
1429
1430 Array<Method*>* methods = scratch_class->methods();
1431
1432 if (methods == NULL || methods->length() == 0) {
1433 // no methods so nothing to do
1434 return true;
1435 }
1436
1437 // rewrite constant pool references in the methods:
1438 for (int i = methods->length() - 1; i >= 0; i--) {
1439 methodHandle method(THREAD, methods->at(i));
1440 methodHandle new_method;
1441 rewrite_cp_refs_in_method(method, &new_method, CHECK_false);
1442 if (!new_method.is_null()) {
1443 // the method has been replaced so save the new method version
1444 methods->at_put(i, new_method());
1445 }
1446 }
1447
1448 return true;
1449 }
1450
1451
1452 // Rewrite constant pool references in the specific method. This code
1453 // was adapted from Rewriter::rewrite_method().
1454 void VM_RedefineClasses::rewrite_cp_refs_in_method(methodHandle method,
1455 methodHandle *new_method_p, TRAPS) {
1456
1457 *new_method_p = methodHandle(); // default is no new method
1458
1459 // We cache a pointer to the bytecodes here in code_base. If GC
1460 // moves the Method*, then the bytecodes will also move which
1461 // will likely cause a crash. We create a No_Safepoint_Verifier
1462 // object to detect whether we pass a possible safepoint in this
1463 // code block.
1464 No_Safepoint_Verifier nsv;
1465
1466 // Bytecodes and their length
1467 address code_base = method->code_base();
1468 int code_length = method->code_size();
1469
1470 int bc_length;
1471 for (int bci = 0; bci < code_length; bci += bc_length) {
1472 address bcp = code_base + bci;
1473 Bytecodes::Code c = (Bytecodes::Code)(*bcp);
1474
1475 bc_length = Bytecodes::length_for(c);
1476 if (bc_length == 0) {
1477 // More complicated bytecodes report a length of zero so
1478 // we have to try again a slightly different way.
1479 bc_length = Bytecodes::length_at(method(), bcp);
1480 }
1481
1482 assert(bc_length != 0, "impossible bytecode length");
1483
1484 switch (c) {
1485 case Bytecodes::_ldc:
1486 {
1487 int cp_index = *(bcp + 1);
1488 int new_index = find_new_index(cp_index);
1489
1490 if (StressLdcRewrite && new_index == 0) {
1491 // If we are stressing ldc -> ldc_w rewriting, then we
1492 // always need a new_index value.
1493 new_index = cp_index;
1494 }
1495 if (new_index != 0) {
1496 // the original index is mapped so we have more work to do
1497 if (!StressLdcRewrite && new_index <= max_jubyte) {
1498 // The new value can still use ldc instead of ldc_w
1499 // unless we are trying to stress ldc -> ldc_w rewriting
1500 RC_TRACE_WITH_THREAD(0x00080000, THREAD,
1501 ("%s@" INTPTR_FORMAT " old=%d, new=%d", Bytecodes::name(c),
1502 bcp, cp_index, new_index));
1503 *(bcp + 1) = new_index;
1504 } else {
1505 RC_TRACE_WITH_THREAD(0x00080000, THREAD,
1506 ("%s->ldc_w@" INTPTR_FORMAT " old=%d, new=%d",
1507 Bytecodes::name(c), bcp, cp_index, new_index));
1508 // the new value needs ldc_w instead of ldc
1509 u_char inst_buffer[4]; // max instruction size is 4 bytes
1510 bcp = (address)inst_buffer;
1511 // construct new instruction sequence
1512 *bcp = Bytecodes::_ldc_w;
1513 bcp++;
1514 // Rewriter::rewrite_method() does not rewrite ldc -> ldc_w.
1515 // See comment below for difference between put_Java_u2()
1516 // and put_native_u2().
1517 Bytes::put_Java_u2(bcp, new_index);
1518
1519 Relocator rc(method, NULL /* no RelocatorListener needed */);
1520 methodHandle m;
1521 {
1522 Pause_No_Safepoint_Verifier pnsv(&nsv);
1523
1524 // ldc is 2 bytes and ldc_w is 3 bytes
1525 m = rc.insert_space_at(bci, 3, inst_buffer, THREAD);
1526 if (m.is_null() || HAS_PENDING_EXCEPTION) {
1527 guarantee(false, "insert_space_at() failed");
1528 }
1529 }
1530
1531 // return the new method so that the caller can update
1532 // the containing class
1533 *new_method_p = method = m;
1534 // switch our bytecode processing loop from the old method
1535 // to the new method
1536 code_base = method->code_base();
1537 code_length = method->code_size();
1538 bcp = code_base + bci;
1539 c = (Bytecodes::Code)(*bcp);
1540 bc_length = Bytecodes::length_for(c);
1541 assert(bc_length != 0, "sanity check");
1542 } // end we need ldc_w instead of ldc
1543 } // end if there is a mapped index
1544 } break;
1545
1546 // these bytecodes have a two-byte constant pool index
1547 case Bytecodes::_anewarray : // fall through
1548 case Bytecodes::_checkcast : // fall through
1549 case Bytecodes::_getfield : // fall through
1550 case Bytecodes::_getstatic : // fall through
1551 case Bytecodes::_instanceof : // fall through
1552 case Bytecodes::_invokedynamic : // fall through
1553 case Bytecodes::_invokeinterface: // fall through
1554 case Bytecodes::_invokespecial : // fall through
1555 case Bytecodes::_invokestatic : // fall through
1556 case Bytecodes::_invokevirtual : // fall through
1557 case Bytecodes::_ldc_w : // fall through
1558 case Bytecodes::_ldc2_w : // fall through
1559 case Bytecodes::_multianewarray : // fall through
1560 case Bytecodes::_new : // fall through
1561 case Bytecodes::_putfield : // fall through
1562 case Bytecodes::_putstatic :
1563 {
1564 address p = bcp + 1;
1565 int cp_index = Bytes::get_Java_u2(p);
1566 int new_index = find_new_index(cp_index);
1567 if (new_index != 0) {
1568 // the original index is mapped so update w/ new value
1569 RC_TRACE_WITH_THREAD(0x00080000, THREAD,
1570 ("%s@" INTPTR_FORMAT " old=%d, new=%d", Bytecodes::name(c),
1571 bcp, cp_index, new_index));
1572 // Rewriter::rewrite_method() uses put_native_u2() in this
1573 // situation because it is reusing the constant pool index
1574 // location for a native index into the ConstantPoolCache.
1575 // Since we are updating the constant pool index prior to
1576 // verification and ConstantPoolCache initialization, we
1577 // need to keep the new index in Java byte order.
1578 Bytes::put_Java_u2(p, new_index);
1579 }
1580 } break;
1581 }
1582 } // end for each bytecode
1583 } // end rewrite_cp_refs_in_method()
1584
1585
1586 // Rewrite constant pool references in the class_annotations field.
1587 bool VM_RedefineClasses::rewrite_cp_refs_in_class_annotations(
1588 instanceKlassHandle scratch_class, TRAPS) {
1589
1590 AnnotationArray* class_annotations = scratch_class->class_annotations();
1591 if (class_annotations == NULL || class_annotations->length() == 0) {
1592 // no class_annotations so nothing to do
1593 return true;
1594 }
1595
1596 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1597 ("class_annotations length=%d", class_annotations->length()));
1598
1599 int byte_i = 0; // byte index into class_annotations
1600 return rewrite_cp_refs_in_annotations_typeArray(class_annotations, byte_i,
1601 THREAD);
1602 }
1603
1604
1605 // Rewrite constant pool references in an annotations typeArray. This
1606 // "structure" is adapted from the RuntimeVisibleAnnotations_attribute
1607 // that is described in section 4.8.15 of the 2nd-edition of the VM spec:
1608 //
1609 // annotations_typeArray {
1610 // u2 num_annotations;
1611 // annotation annotations[num_annotations];
1612 // }
1613 //
1614 bool VM_RedefineClasses::rewrite_cp_refs_in_annotations_typeArray(
1615 AnnotationArray* annotations_typeArray, int &byte_i_ref, TRAPS) {
1616
1617 if ((byte_i_ref + 2) > annotations_typeArray->length()) {
1618 // not enough room for num_annotations field
1619 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1620 ("length() is too small for num_annotations field"));
1621 return false;
1622 }
1623
1624 u2 num_annotations = Bytes::get_Java_u2((address)
1625 annotations_typeArray->adr_at(byte_i_ref));
1626 byte_i_ref += 2;
1627
1628 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1629 ("num_annotations=%d", num_annotations));
1630
1631 int calc_num_annotations = 0;
1632 for (; calc_num_annotations < num_annotations; calc_num_annotations++) {
1633 if (!rewrite_cp_refs_in_annotation_struct(annotations_typeArray,
1634 byte_i_ref, THREAD)) {
1635 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1636 ("bad annotation_struct at %d", calc_num_annotations));
1637 // propagate failure back to caller
1638 return false;
1639 }
1640 }
1641 assert(num_annotations == calc_num_annotations, "sanity check");
1642
1643 return true;
1644 } // end rewrite_cp_refs_in_annotations_typeArray()
1645
1646
1647 // Rewrite constant pool references in the annotation struct portion of
1648 // an annotations_typeArray. This "structure" is from section 4.8.15 of
1649 // the 2nd-edition of the VM spec:
1650 //
1651 // struct annotation {
1652 // u2 type_index;
1653 // u2 num_element_value_pairs;
1654 // {
1655 // u2 element_name_index;
1656 // element_value value;
1657 // } element_value_pairs[num_element_value_pairs];
1658 // }
1659 //
1660 bool VM_RedefineClasses::rewrite_cp_refs_in_annotation_struct(
1661 AnnotationArray* annotations_typeArray, int &byte_i_ref, TRAPS) {
1662 if ((byte_i_ref + 2 + 2) > annotations_typeArray->length()) {
1663 // not enough room for smallest annotation_struct
1664 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1665 ("length() is too small for annotation_struct"));
1666 return false;
1667 }
1668
1669 u2 type_index = rewrite_cp_ref_in_annotation_data(annotations_typeArray,
1670 byte_i_ref, "mapped old type_index=%d", THREAD);
1671
1672 u2 num_element_value_pairs = Bytes::get_Java_u2((address)
1673 annotations_typeArray->adr_at(byte_i_ref));
1674 byte_i_ref += 2;
1675
1676 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1677 ("type_index=%d num_element_value_pairs=%d", type_index,
1678 num_element_value_pairs));
1679
1680 int calc_num_element_value_pairs = 0;
1681 for (; calc_num_element_value_pairs < num_element_value_pairs;
1682 calc_num_element_value_pairs++) {
1683 if ((byte_i_ref + 2) > annotations_typeArray->length()) {
1684 // not enough room for another element_name_index, let alone
1685 // the rest of another component
1686 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1687 ("length() is too small for element_name_index"));
1688 return false;
1689 }
1690
1691 u2 element_name_index = rewrite_cp_ref_in_annotation_data(
1692 annotations_typeArray, byte_i_ref,
1693 "mapped old element_name_index=%d", THREAD);
1694
1695 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1696 ("element_name_index=%d", element_name_index));
1697
1698 if (!rewrite_cp_refs_in_element_value(annotations_typeArray,
1699 byte_i_ref, THREAD)) {
1700 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1701 ("bad element_value at %d", calc_num_element_value_pairs));
1702 // propagate failure back to caller
1703 return false;
1704 }
1705 } // end for each component
1706 assert(num_element_value_pairs == calc_num_element_value_pairs,
1707 "sanity check");
1708
1709 return true;
1710 } // end rewrite_cp_refs_in_annotation_struct()
1711
1712
1713 // Rewrite a constant pool reference at the current position in
1714 // annotations_typeArray if needed. Returns the original constant
1715 // pool reference if a rewrite was not needed or the new constant
1716 // pool reference if a rewrite was needed.
1717 u2 VM_RedefineClasses::rewrite_cp_ref_in_annotation_data(
1718 AnnotationArray* annotations_typeArray, int &byte_i_ref,
1719 const char * trace_mesg, TRAPS) {
1720
1721 address cp_index_addr = (address)
1722 annotations_typeArray->adr_at(byte_i_ref);
1723 u2 old_cp_index = Bytes::get_Java_u2(cp_index_addr);
1724 u2 new_cp_index = find_new_index(old_cp_index);
1725 if (new_cp_index != 0) {
1726 RC_TRACE_WITH_THREAD(0x02000000, THREAD, (trace_mesg, old_cp_index));
1727 Bytes::put_Java_u2(cp_index_addr, new_cp_index);
1728 old_cp_index = new_cp_index;
1729 }
1730 byte_i_ref += 2;
1731 return old_cp_index;
1732 }
1733
1734
1735 // Rewrite constant pool references in the element_value portion of an
1736 // annotations_typeArray. This "structure" is from section 4.8.15.1 of
1737 // the 2nd-edition of the VM spec:
1738 //
1739 // struct element_value {
1740 // u1 tag;
1741 // union {
1742 // u2 const_value_index;
1743 // {
1744 // u2 type_name_index;
1745 // u2 const_name_index;
1746 // } enum_const_value;
1747 // u2 class_info_index;
1748 // annotation annotation_value;
1749 // struct {
1750 // u2 num_values;
1751 // element_value values[num_values];
1752 // } array_value;
1753 // } value;
1754 // }
1755 //
1756 bool VM_RedefineClasses::rewrite_cp_refs_in_element_value(
1757 AnnotationArray* annotations_typeArray, int &byte_i_ref, TRAPS) {
1758
1759 if ((byte_i_ref + 1) > annotations_typeArray->length()) {
1760 // not enough room for a tag let alone the rest of an element_value
1761 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1762 ("length() is too small for a tag"));
1763 return false;
1764 }
1765
1766 u1 tag = annotations_typeArray->at(byte_i_ref);
1767 byte_i_ref++;
1768 RC_TRACE_WITH_THREAD(0x02000000, THREAD, ("tag='%c'", tag));
1769
1770 switch (tag) {
1771 // These BaseType tag values are from Table 4.2 in VM spec:
1772 case 'B': // byte
1773 case 'C': // char
1774 case 'D': // double
1775 case 'F': // float
1776 case 'I': // int
1777 case 'J': // long
1778 case 'S': // short
1779 case 'Z': // boolean
1780
1781 // The remaining tag values are from Table 4.8 in the 2nd-edition of
1782 // the VM spec:
1783 case 's':
1784 {
1785 // For the above tag values (including the BaseType values),
1786 // value.const_value_index is right union field.
1787
1788 if ((byte_i_ref + 2) > annotations_typeArray->length()) {
1789 // not enough room for a const_value_index
1790 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1791 ("length() is too small for a const_value_index"));
1792 return false;
1793 }
1794
1795 u2 const_value_index = rewrite_cp_ref_in_annotation_data(
1796 annotations_typeArray, byte_i_ref,
1797 "mapped old const_value_index=%d", THREAD);
1798
1799 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1800 ("const_value_index=%d", const_value_index));
1801 } break;
1802
1803 case 'e':
1804 {
1805 // for the above tag value, value.enum_const_value is right union field
1806
1807 if ((byte_i_ref + 4) > annotations_typeArray->length()) {
1808 // not enough room for a enum_const_value
1809 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1810 ("length() is too small for a enum_const_value"));
1811 return false;
1812 }
1813
1814 u2 type_name_index = rewrite_cp_ref_in_annotation_data(
1815 annotations_typeArray, byte_i_ref,
1816 "mapped old type_name_index=%d", THREAD);
1817
1818 u2 const_name_index = rewrite_cp_ref_in_annotation_data(
1819 annotations_typeArray, byte_i_ref,
1820 "mapped old const_name_index=%d", THREAD);
1821
1822 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1823 ("type_name_index=%d const_name_index=%d", type_name_index,
1824 const_name_index));
1825 } break;
1826
1827 case 'c':
1828 {
1829 // for the above tag value, value.class_info_index is right union field
1830
1831 if ((byte_i_ref + 2) > annotations_typeArray->length()) {
1832 // not enough room for a class_info_index
1833 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1834 ("length() is too small for a class_info_index"));
1835 return false;
1836 }
1837
1838 u2 class_info_index = rewrite_cp_ref_in_annotation_data(
1839 annotations_typeArray, byte_i_ref,
1840 "mapped old class_info_index=%d", THREAD);
1841
1842 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1843 ("class_info_index=%d", class_info_index));
1844 } break;
1845
1846 case '@':
1847 // For the above tag value, value.attr_value is the right union
1848 // field. This is a nested annotation.
1849 if (!rewrite_cp_refs_in_annotation_struct(annotations_typeArray,
1850 byte_i_ref, THREAD)) {
1851 // propagate failure back to caller
1852 return false;
1853 }
1854 break;
1855
1856 case '[':
1857 {
1858 if ((byte_i_ref + 2) > annotations_typeArray->length()) {
1859 // not enough room for a num_values field
1860 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1861 ("length() is too small for a num_values field"));
1862 return false;
1863 }
1864
1865 // For the above tag value, value.array_value is the right union
1866 // field. This is an array of nested element_value.
1867 u2 num_values = Bytes::get_Java_u2((address)
1868 annotations_typeArray->adr_at(byte_i_ref));
1869 byte_i_ref += 2;
1870 RC_TRACE_WITH_THREAD(0x02000000, THREAD, ("num_values=%d", num_values));
1871
1872 int calc_num_values = 0;
1873 for (; calc_num_values < num_values; calc_num_values++) {
1874 if (!rewrite_cp_refs_in_element_value(
1875 annotations_typeArray, byte_i_ref, THREAD)) {
1876 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1877 ("bad nested element_value at %d", calc_num_values));
1878 // propagate failure back to caller
1879 return false;
1880 }
1881 }
1882 assert(num_values == calc_num_values, "sanity check");
1883 } break;
1884
1885 default:
1886 RC_TRACE_WITH_THREAD(0x02000000, THREAD, ("bad tag=0x%x", tag));
1887 return false;
1888 } // end decode tag field
1889
1890 return true;
1891 } // end rewrite_cp_refs_in_element_value()
1892
1893
1894 // Rewrite constant pool references in a fields_annotations field.
1895 bool VM_RedefineClasses::rewrite_cp_refs_in_fields_annotations(
1896 instanceKlassHandle scratch_class, TRAPS) {
1897
1898 Annotations* sca = scratch_class->annotations();
1899 if (sca == NULL) return true;
1900
1901 Array<AnnotationArray*>* fields_annotations = sca->fields_annotations();
1902
1903 if (fields_annotations == NULL || fields_annotations->length() == 0) {
1904 // no fields_annotations so nothing to do
1905 return true;
1906 }
1907
1908 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1909 ("fields_annotations length=%d", fields_annotations->length()));
1910
1911 for (int i = 0; i < fields_annotations->length(); i++) {
1912 AnnotationArray* field_annotations = fields_annotations->at(i);
1913 if (field_annotations == NULL || field_annotations->length() == 0) {
1914 // this field does not have any annotations so skip it
1915 continue;
1916 }
1917
1918 int byte_i = 0; // byte index into field_annotations
1919 if (!rewrite_cp_refs_in_annotations_typeArray(field_annotations, byte_i,
1920 THREAD)) {
1921 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1922 ("bad field_annotations at %d", i));
1923 // propagate failure back to caller
1924 return false;
1925 }
1926 }
1927
1928 return true;
1929 } // end rewrite_cp_refs_in_fields_annotations()
1930
1931
1932 // Rewrite constant pool references in a methods_annotations field.
1933 bool VM_RedefineClasses::rewrite_cp_refs_in_methods_annotations(
1934 instanceKlassHandle scratch_class, TRAPS) {
1935
1936 Annotations* sca = scratch_class->annotations();
1937 if (sca == NULL) return true;
1938
1939 Array<AnnotationArray*>* methods_annotations = sca->methods_annotations();
1940
1941 if (methods_annotations == NULL || methods_annotations->length() == 0) {
1942 // no methods_annotations so nothing to do
1943 return true;
1944 }
1945
1946 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1947 ("methods_annotations length=%d", methods_annotations->length()));
1948
1949 for (int i = 0; i < methods_annotations->length(); i++) {
1950 AnnotationArray* method_annotations = methods_annotations->at(i);
1951 if (method_annotations == NULL || method_annotations->length() == 0) {
1952 // this method does not have any annotations so skip it
1953 continue;
1954 }
1955
1956 int byte_i = 0; // byte index into method_annotations
1957 if (!rewrite_cp_refs_in_annotations_typeArray(method_annotations, byte_i,
1958 THREAD)) {
1959 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1960 ("bad method_annotations at %d", i));
1961 // propagate failure back to caller
1962 return false;
1963 }
1964 }
1965
1966 return true;
1967 } // end rewrite_cp_refs_in_methods_annotations()
1968
1969
1970 // Rewrite constant pool references in a methods_parameter_annotations
1971 // field. This "structure" is adapted from the
1972 // RuntimeVisibleParameterAnnotations_attribute described in section
1973 // 4.8.17 of the 2nd-edition of the VM spec:
1974 //
1975 // methods_parameter_annotations_typeArray {
1976 // u1 num_parameters;
1977 // {
1978 // u2 num_annotations;
1979 // annotation annotations[num_annotations];
1980 // } parameter_annotations[num_parameters];
1981 // }
1982 //
1983 bool VM_RedefineClasses::rewrite_cp_refs_in_methods_parameter_annotations(
1984 instanceKlassHandle scratch_class, TRAPS) {
1985
1986 Annotations* sca = scratch_class->annotations();
1987 if (sca == NULL) return true;
1988
1989 Array<AnnotationArray*>* methods_parameter_annotations =
1990 sca->methods_parameter_annotations();
1991
1992 if (methods_parameter_annotations == NULL
1993 || methods_parameter_annotations->length() == 0) {
1994 // no methods_parameter_annotations so nothing to do
1995 return true;
1996 }
1997
1998 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
1999 ("methods_parameter_annotations length=%d",
2000 methods_parameter_annotations->length()));
2001
2002 for (int i = 0; i < methods_parameter_annotations->length(); i++) {
2003 AnnotationArray* method_parameter_annotations = methods_parameter_annotations->at(i);
2004 if (method_parameter_annotations == NULL
2005 || method_parameter_annotations->length() == 0) {
2006 // this method does not have any parameter annotations so skip it
2007 continue;
2008 }
2009
2010 if (method_parameter_annotations->length() < 1) {
2011 // not enough room for a num_parameters field
2012 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
2013 ("length() is too small for a num_parameters field at %d", i));
2014 return false;
2015 }
2016
2017 int byte_i = 0; // byte index into method_parameter_annotations
2018
2019 u1 num_parameters = method_parameter_annotations->at(byte_i);
2020 byte_i++;
2021
2022 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
2023 ("num_parameters=%d", num_parameters));
2024
2025 int calc_num_parameters = 0;
2026 for (; calc_num_parameters < num_parameters; calc_num_parameters++) {
2027 if (!rewrite_cp_refs_in_annotations_typeArray(
2028 method_parameter_annotations, byte_i, THREAD)) {
2029 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
2030 ("bad method_parameter_annotations at %d", calc_num_parameters));
2031 // propagate failure back to caller
2032 return false;
2033 }
2034 }
2035 assert(num_parameters == calc_num_parameters, "sanity check");
2036 }
2037
2038 return true;
2039 } // end rewrite_cp_refs_in_methods_parameter_annotations()
2040
2041
2042 // Rewrite constant pool references in a methods_default_annotations
2043 // field. This "structure" is adapted from the AnnotationDefault_attribute
2044 // that is described in section 4.8.19 of the 2nd-edition of the VM spec:
2045 //
2046 // methods_default_annotations_typeArray {
2047 // element_value default_value;
2048 // }
2049 //
2050 bool VM_RedefineClasses::rewrite_cp_refs_in_methods_default_annotations(
2051 instanceKlassHandle scratch_class, TRAPS) {
2052
2053 Annotations* sca = scratch_class->annotations();
2054 if (sca == NULL) return true;
2055
2056 Array<AnnotationArray*>* methods_default_annotations =
2057 sca->methods_default_annotations();
2058
2059 if (methods_default_annotations == NULL
2060 || methods_default_annotations->length() == 0) {
2061 // no methods_default_annotations so nothing to do
2062 return true;
2063 }
2064
2065 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
2066 ("methods_default_annotations length=%d",
2067 methods_default_annotations->length()));
2068
2069 for (int i = 0; i < methods_default_annotations->length(); i++) {
2070 AnnotationArray* method_default_annotations = methods_default_annotations->at(i);
2071 if (method_default_annotations == NULL
2072 || method_default_annotations->length() == 0) {
2073 // this method does not have any default annotations so skip it
2074 continue;
2075 }
2076
2077 int byte_i = 0; // byte index into method_default_annotations
2078
2079 if (!rewrite_cp_refs_in_element_value(
2080 method_default_annotations, byte_i, THREAD)) {
2081 RC_TRACE_WITH_THREAD(0x02000000, THREAD,
2082 ("bad default element_value at %d", i));
2083 // propagate failure back to caller
2084 return false;
2085 }
2086 }
2087
2088 return true;
2089 } // end rewrite_cp_refs_in_methods_default_annotations()
2090
2091
2092 // Rewrite constant pool references in the method's stackmap table.
2093 // These "structures" are adapted from the StackMapTable_attribute that
2094 // is described in section 4.8.4 of the 6.0 version of the VM spec
2095 // (dated 2005.10.26):
2096 // file:///net/quincunx.sfbay/export/gbracha/ClassFile-Java6.pdf
2097 //
2098 // stack_map {
2099 // u2 number_of_entries;
2100 // stack_map_frame entries[number_of_entries];
2101 // }
2102 //
2103 void VM_RedefineClasses::rewrite_cp_refs_in_stack_map_table(
2104 methodHandle method, TRAPS) {
2105
2106 if (!method->has_stackmap_table()) {
2107 return;
2108 }
2109
2110 AnnotationArray* stackmap_data = method->stackmap_data();
2111 address stackmap_p = (address)stackmap_data->adr_at(0);
2112 address stackmap_end = stackmap_p + stackmap_data->length();
2113
2114 assert(stackmap_p + 2 <= stackmap_end, "no room for number_of_entries");
2115 u2 number_of_entries = Bytes::get_Java_u2(stackmap_p);
2116 stackmap_p += 2;
2117
2118 RC_TRACE_WITH_THREAD(0x04000000, THREAD,
2119 ("number_of_entries=%u", number_of_entries));
2120
2121 // walk through each stack_map_frame
2122 u2 calc_number_of_entries = 0;
2123 for (; calc_number_of_entries < number_of_entries; calc_number_of_entries++) {
2124 // The stack_map_frame structure is a u1 frame_type followed by
2125 // 0 or more bytes of data:
2126 //
2127 // union stack_map_frame {
2128 // same_frame;
2129 // same_locals_1_stack_item_frame;
2130 // same_locals_1_stack_item_frame_extended;
2131 // chop_frame;
2132 // same_frame_extended;
2133 // append_frame;
2134 // full_frame;
2135 // }
2136
2137 assert(stackmap_p + 1 <= stackmap_end, "no room for frame_type");
2138 // The Linux compiler does not like frame_type to be u1 or u2. It
2139 // issues the following warning for the first if-statement below:
2140 //
2141 // "warning: comparison is always true due to limited range of data type"
2142 //
2143 u4 frame_type = *stackmap_p;
2144 stackmap_p++;
2145
2146 // same_frame {
2147 // u1 frame_type = SAME; /* 0-63 */
2148 // }
2149 if (frame_type >= 0 && frame_type <= 63) {
2150 // nothing more to do for same_frame
2151 }
2152
2153 // same_locals_1_stack_item_frame {
2154 // u1 frame_type = SAME_LOCALS_1_STACK_ITEM; /* 64-127 */
2155 // verification_type_info stack[1];
2156 // }
2157 else if (frame_type >= 64 && frame_type <= 127) {
2158 rewrite_cp_refs_in_verification_type_info(stackmap_p, stackmap_end,
2159 calc_number_of_entries, frame_type, THREAD);
2160 }
2161
2162 // reserved for future use
2163 else if (frame_type >= 128 && frame_type <= 246) {
2164 // nothing more to do for reserved frame_types
2165 }
2166
2167 // same_locals_1_stack_item_frame_extended {
2168 // u1 frame_type = SAME_LOCALS_1_STACK_ITEM_EXTENDED; /* 247 */
2169 // u2 offset_delta;
2170 // verification_type_info stack[1];
2171 // }
2172 else if (frame_type == 247) {
2173 stackmap_p += 2;
2174 rewrite_cp_refs_in_verification_type_info(stackmap_p, stackmap_end,
2175 calc_number_of_entries, frame_type, THREAD);
2176 }
2177
2178 // chop_frame {
2179 // u1 frame_type = CHOP; /* 248-250 */
2180 // u2 offset_delta;
2181 // }
2182 else if (frame_type >= 248 && frame_type <= 250) {
2183 stackmap_p += 2;
2184 }
2185
2186 // same_frame_extended {
2187 // u1 frame_type = SAME_FRAME_EXTENDED; /* 251*/
2188 // u2 offset_delta;
2189 // }
2190 else if (frame_type == 251) {
2191 stackmap_p += 2;
2192 }
2193
2194 // append_frame {
2195 // u1 frame_type = APPEND; /* 252-254 */
2196 // u2 offset_delta;
2197 // verification_type_info locals[frame_type - 251];
2198 // }
2199 else if (frame_type >= 252 && frame_type <= 254) {
2200 assert(stackmap_p + 2 <= stackmap_end,
2201 "no room for offset_delta");
2202 stackmap_p += 2;
2203 u1 len = frame_type - 251;
2204 for (u1 i = 0; i < len; i++) {
2205 rewrite_cp_refs_in_verification_type_info(stackmap_p, stackmap_end,
2206 calc_number_of_entries, frame_type, THREAD);
2207 }
2208 }
2209
2210 // full_frame {
2211 // u1 frame_type = FULL_FRAME; /* 255 */
2212 // u2 offset_delta;
2213 // u2 number_of_locals;
2214 // verification_type_info locals[number_of_locals];
2215 // u2 number_of_stack_items;
2216 // verification_type_info stack[number_of_stack_items];
2217 // }
2218 else if (frame_type == 255) {
2219 assert(stackmap_p + 2 + 2 <= stackmap_end,
2220 "no room for smallest full_frame");
2221 stackmap_p += 2;
2222
2223 u2 number_of_locals = Bytes::get_Java_u2(stackmap_p);
2224 stackmap_p += 2;
2225
2226 for (u2 locals_i = 0; locals_i < number_of_locals; locals_i++) {
2227 rewrite_cp_refs_in_verification_type_info(stackmap_p, stackmap_end,
2228 calc_number_of_entries, frame_type, THREAD);
2229 }
2230
2231 // Use the largest size for the number_of_stack_items, but only get
2232 // the right number of bytes.
2233 u2 number_of_stack_items = Bytes::get_Java_u2(stackmap_p);
2234 stackmap_p += 2;
2235
2236 for (u2 stack_i = 0; stack_i < number_of_stack_items; stack_i++) {
2237 rewrite_cp_refs_in_verification_type_info(stackmap_p, stackmap_end,
2238 calc_number_of_entries, frame_type, THREAD);
2239 }
2240 }
2241 } // end while there is a stack_map_frame
2242 assert(number_of_entries == calc_number_of_entries, "sanity check");
2243 } // end rewrite_cp_refs_in_stack_map_table()
2244
2245
2246 // Rewrite constant pool references in the verification type info
2247 // portion of the method's stackmap table. These "structures" are
2248 // adapted from the StackMapTable_attribute that is described in
2249 // section 4.8.4 of the 6.0 version of the VM spec (dated 2005.10.26):
2250 // file:///net/quincunx.sfbay/export/gbracha/ClassFile-Java6.pdf
2251 //
2252 // The verification_type_info structure is a u1 tag followed by 0 or
2253 // more bytes of data:
2254 //
2255 // union verification_type_info {
2256 // Top_variable_info;
2257 // Integer_variable_info;
2258 // Float_variable_info;
2259 // Long_variable_info;
2260 // Double_variable_info;
2261 // Null_variable_info;
2262 // UninitializedThis_variable_info;
2263 // Object_variable_info;
2264 // Uninitialized_variable_info;
2265 // }
2266 //
2267 void VM_RedefineClasses::rewrite_cp_refs_in_verification_type_info(
2268 address& stackmap_p_ref, address stackmap_end, u2 frame_i,
2269 u1 frame_type, TRAPS) {
2270
2271 assert(stackmap_p_ref + 1 <= stackmap_end, "no room for tag");
2272 u1 tag = *stackmap_p_ref;
2273 stackmap_p_ref++;
2274
2275 switch (tag) {
2276 // Top_variable_info {
2277 // u1 tag = ITEM_Top; /* 0 */
2278 // }
2279 // verificationType.hpp has zero as ITEM_Bogus instead of ITEM_Top
2280 case 0: // fall through
2281
2282 // Integer_variable_info {
2283 // u1 tag = ITEM_Integer; /* 1 */
2284 // }
2285 case ITEM_Integer: // fall through
2286
2287 // Float_variable_info {
2288 // u1 tag = ITEM_Float; /* 2 */
2289 // }
2290 case ITEM_Float: // fall through
2291
2292 // Double_variable_info {
2293 // u1 tag = ITEM_Double; /* 3 */
2294 // }
2295 case ITEM_Double: // fall through
2296
2297 // Long_variable_info {
2298 // u1 tag = ITEM_Long; /* 4 */
2299 // }
2300 case ITEM_Long: // fall through
2301
2302 // Null_variable_info {
2303 // u1 tag = ITEM_Null; /* 5 */
2304 // }
2305 case ITEM_Null: // fall through
2306
2307 // UninitializedThis_variable_info {
2308 // u1 tag = ITEM_UninitializedThis; /* 6 */
2309 // }
2310 case ITEM_UninitializedThis:
2311 // nothing more to do for the above tag types
2312 break;
2313
2314 // Object_variable_info {
2315 // u1 tag = ITEM_Object; /* 7 */
2316 // u2 cpool_index;
2317 // }
2318 case ITEM_Object:
2319 {
2320 assert(stackmap_p_ref + 2 <= stackmap_end, "no room for cpool_index");
2321 u2 cpool_index = Bytes::get_Java_u2(stackmap_p_ref);
2322 u2 new_cp_index = find_new_index(cpool_index);
2323 if (new_cp_index != 0) {
2324 RC_TRACE_WITH_THREAD(0x04000000, THREAD,
2325 ("mapped old cpool_index=%d", cpool_index));
2326 Bytes::put_Java_u2(stackmap_p_ref, new_cp_index);
2327 cpool_index = new_cp_index;
2328 }
2329 stackmap_p_ref += 2;
2330
2331 RC_TRACE_WITH_THREAD(0x04000000, THREAD,
2332 ("frame_i=%u, frame_type=%u, cpool_index=%d", frame_i,
2333 frame_type, cpool_index));
2334 } break;
2335
2336 // Uninitialized_variable_info {
2337 // u1 tag = ITEM_Uninitialized; /* 8 */
2338 // u2 offset;
2339 // }
2340 case ITEM_Uninitialized:
2341 assert(stackmap_p_ref + 2 <= stackmap_end, "no room for offset");
2342 stackmap_p_ref += 2;
2343 break;
2344
2345 default:
2346 RC_TRACE_WITH_THREAD(0x04000000, THREAD,
2347 ("frame_i=%u, frame_type=%u, bad tag=0x%x", frame_i, frame_type, tag));
2348 ShouldNotReachHere();
2349 break;
2350 } // end switch (tag)
2351 } // end rewrite_cp_refs_in_verification_type_info()
2352
2353
2354 // Change the constant pool associated with klass scratch_class to
2355 // scratch_cp. If shrink is true, then scratch_cp_length elements
2356 // are copied from scratch_cp to a smaller constant pool and the
2357 // smaller constant pool is associated with scratch_class.
2358 void VM_RedefineClasses::set_new_constant_pool(
2359 ClassLoaderData* loader_data,
2360 instanceKlassHandle scratch_class, constantPoolHandle scratch_cp,
2361 int scratch_cp_length, TRAPS) {
2362 assert(scratch_cp->length() >= scratch_cp_length, "sanity check");
2363
2364 // scratch_cp is a merged constant pool and has enough space for a
2365 // worst case merge situation. We want to associate the minimum
2366 // sized constant pool with the klass to save space.
2367 constantPoolHandle smaller_cp(THREAD,
2368 ConstantPool::allocate(loader_data, scratch_cp_length, THREAD));
2369
2370 // preserve version() value in the smaller copy
2371 int version = scratch_cp->version();
2372 assert(version != 0, "sanity check");
2373 smaller_cp->set_version(version);
2374
2375 // attach klass to new constant pool
2376 // reference to the cp holder is needed for copy_operands()
2377 smaller_cp->set_pool_holder(scratch_class());
2378
2379 scratch_cp->copy_cp_to(1, scratch_cp_length - 1, smaller_cp, 1, THREAD);
2380 scratch_cp = smaller_cp;
2381
2382 // attach new constant pool to klass
2383 scratch_class->set_constants(scratch_cp());
2384
2385 int i; // for portability
2386
2387 // update each field in klass to use new constant pool indices as needed
2388 for (JavaFieldStream fs(scratch_class); !fs.done(); fs.next()) {
2389 jshort cur_index = fs.name_index();
2390 jshort new_index = find_new_index(cur_index);
2391 if (new_index != 0) {
2392 RC_TRACE_WITH_THREAD(0x00080000, THREAD,
2393 ("field-name_index change: %d to %d", cur_index, new_index));
2394 fs.set_name_index(new_index);
2395 }
2396 cur_index = fs.signature_index();
2397 new_index = find_new_index(cur_index);
2398 if (new_index != 0) {
2399 RC_TRACE_WITH_THREAD(0x00080000, THREAD,
2400 ("field-signature_index change: %d to %d", cur_index, new_index));
2401 fs.set_signature_index(new_index);
2402 }
2403 cur_index = fs.initval_index();
2404 new_index = find_new_index(cur_index);
2405 if (new_index != 0) {
2406 RC_TRACE_WITH_THREAD(0x00080000, THREAD,
2407 ("field-initval_index change: %d to %d", cur_index, new_index));
2408 fs.set_initval_index(new_index);
2409 }
2410 cur_index = fs.generic_signature_index();
2411 new_index = find_new_index(cur_index);
2412 if (new_index != 0) {
2413 RC_TRACE_WITH_THREAD(0x00080000, THREAD,
2414 ("field-generic_signature change: %d to %d", cur_index, new_index));
2415 fs.set_generic_signature_index(new_index);
2416 }
2417 } // end for each field
2418
2419 // Update constant pool indices in the inner classes info to use
2420 // new constant indices as needed. The inner classes info is a
2421 // quadruple:
2422 // (inner_class_info, outer_class_info, inner_name, inner_access_flags)
2423 InnerClassesIterator iter(scratch_class);
2424 for (; !iter.done(); iter.next()) {
2425 int cur_index = iter.inner_class_info_index();
2426 if (cur_index == 0) {
2427 continue; // JVM spec. allows null inner class refs so skip it
2428 }
2429 int new_index = find_new_index(cur_index);
2430 if (new_index != 0) {
2431 RC_TRACE_WITH_THREAD(0x00080000, THREAD,
2432 ("inner_class_info change: %d to %d", cur_index, new_index));
2433 iter.set_inner_class_info_index(new_index);
2434 }
2435 cur_index = iter.outer_class_info_index();
2436 new_index = find_new_index(cur_index);
2437 if (new_index != 0) {
2438 RC_TRACE_WITH_THREAD(0x00080000, THREAD,
2439 ("outer_class_info change: %d to %d", cur_index, new_index));
2440 iter.set_outer_class_info_index(new_index);
2441 }
2442 cur_index = iter.inner_name_index();
2443 new_index = find_new_index(cur_index);
2444 if (new_index != 0) {
2445 RC_TRACE_WITH_THREAD(0x00080000, THREAD,
2446 ("inner_name change: %d to %d", cur_index, new_index));
2447 iter.set_inner_name_index(new_index);
2448 }
2449 } // end for each inner class
2450
2451 // Attach each method in klass to the new constant pool and update
2452 // to use new constant pool indices as needed:
2453 Array<Method*>* methods = scratch_class->methods();
2454 for (i = methods->length() - 1; i >= 0; i--) {
2455 methodHandle method(THREAD, methods->at(i));
2456 method->set_constants(scratch_cp());
2457
2458 int new_index = find_new_index(method->name_index());
2459 if (new_index != 0) {
2460 RC_TRACE_WITH_THREAD(0x00080000, THREAD,
2461 ("method-name_index change: %d to %d", method->name_index(),
2462 new_index));
2463 method->set_name_index(new_index);
2464 }
2465 new_index = find_new_index(method->signature_index());
2466 if (new_index != 0) {
2467 RC_TRACE_WITH_THREAD(0x00080000, THREAD,
2468 ("method-signature_index change: %d to %d",
2469 method->signature_index(), new_index));
2470 method->set_signature_index(new_index);
2471 }
2472 new_index = find_new_index(method->generic_signature_index());
2473 if (new_index != 0) {
2474 RC_TRACE_WITH_THREAD(0x00080000, THREAD,
2475 ("method-generic_signature_index change: %d to %d",
2476 method->generic_signature_index(), new_index));
2477 method->set_generic_signature_index(new_index);
2478 }
2479
2480 // Update constant pool indices in the method's checked exception
2481 // table to use new constant indices as needed.
2482 int cext_length = method->checked_exceptions_length();
2483 if (cext_length > 0) {
2484 CheckedExceptionElement * cext_table =
2485 method->checked_exceptions_start();
2486 for (int j = 0; j < cext_length; j++) {
2487 int cur_index = cext_table[j].class_cp_index;
2488 int new_index = find_new_index(cur_index);
2489 if (new_index != 0) {
2490 RC_TRACE_WITH_THREAD(0x00080000, THREAD,
2491 ("cext-class_cp_index change: %d to %d", cur_index, new_index));
2492 cext_table[j].class_cp_index = (u2)new_index;
2493 }
2494 } // end for each checked exception table entry
2495 } // end if there are checked exception table entries
2496
2497 // Update each catch type index in the method's exception table
2498 // to use new constant pool indices as needed. The exception table
2499 // holds quadruple entries of the form:
2500 // (beg_bci, end_bci, handler_bci, klass_index)
2501
2502 ExceptionTable ex_table(method());
2503 int ext_length = ex_table.length();
2504
2505 for (int j = 0; j < ext_length; j ++) {
2506 int cur_index = ex_table.catch_type_index(j);
2507 int new_index = find_new_index(cur_index);
2508 if (new_index != 0) {
2509 RC_TRACE_WITH_THREAD(0x00080000, THREAD,
2510 ("ext-klass_index change: %d to %d", cur_index, new_index));
2511 ex_table.set_catch_type_index(j, new_index);
2512 }
2513 } // end for each exception table entry
2514
2515 // Update constant pool indices in the method's local variable
2516 // table to use new constant indices as needed. The local variable
2517 // table hold sextuple entries of the form:
2518 // (start_pc, length, name_index, descriptor_index, signature_index, slot)
2519 int lvt_length = method->localvariable_table_length();
2520 if (lvt_length > 0) {
2521 LocalVariableTableElement * lv_table =
2522 method->localvariable_table_start();
2523 for (int j = 0; j < lvt_length; j++) {
2524 int cur_index = lv_table[j].name_cp_index;
2525 int new_index = find_new_index(cur_index);
2526 if (new_index != 0) {
2527 RC_TRACE_WITH_THREAD(0x00080000, THREAD,
2528 ("lvt-name_cp_index change: %d to %d", cur_index, new_index));
2529 lv_table[j].name_cp_index = (u2)new_index;
2530 }
2531 cur_index = lv_table[j].descriptor_cp_index;
2532 new_index = find_new_index(cur_index);
2533 if (new_index != 0) {
2534 RC_TRACE_WITH_THREAD(0x00080000, THREAD,
2535 ("lvt-descriptor_cp_index change: %d to %d", cur_index,
2536 new_index));
2537 lv_table[j].descriptor_cp_index = (u2)new_index;
2538 }
2539 cur_index = lv_table[j].signature_cp_index;
2540 new_index = find_new_index(cur_index);
2541 if (new_index != 0) {
2542 RC_TRACE_WITH_THREAD(0x00080000, THREAD,
2543 ("lvt-signature_cp_index change: %d to %d", cur_index, new_index));
2544 lv_table[j].signature_cp_index = (u2)new_index;
2545 }
2546 } // end for each local variable table entry
2547 } // end if there are local variable table entries
2548
2549 rewrite_cp_refs_in_stack_map_table(method, THREAD);
2550 } // end for each method
2551 } // end set_new_constant_pool()
2552
2553
2554 void VM_RedefineClasses::adjust_array_vtable(Klass* k_oop) {
2555 ArrayKlass* ak = ArrayKlass::cast(k_oop);
2556 bool trace_name_printed = false;
2557 ak->vtable()->adjust_method_entries(_matching_old_methods,
2558 _matching_new_methods,
2559 _matching_methods_length,
2560 &trace_name_printed);
2561 }
2562
2563 // Unevolving classes may point to methods of the_class directly
2564 // from their constant pool caches, itables, and/or vtables. We
2565 // use the SystemDictionary::classes_do() facility and this helper
2566 // to fix up these pointers.
2567 //
2568 // Note: We currently don't support updating the vtable in
2569 // arrayKlassOops. See Open Issues in jvmtiRedefineClasses.hpp.
2570 void VM_RedefineClasses::adjust_cpool_cache_and_vtable(Klass* k_oop,
2571 ClassLoaderData* initiating_loader,
2572 TRAPS) {
2573 Klass *k = k_oop;
2574 if (k->oop_is_instance()) {
2575 HandleMark hm(THREAD);
2576 InstanceKlass *ik = (InstanceKlass *) k;
2577
2578 // HotSpot specific optimization! HotSpot does not currently
2579 // support delegation from the bootstrap class loader to a
2580 // user-defined class loader. This means that if the bootstrap
2581 // class loader is the initiating class loader, then it will also
2582 // be the defining class loader. This also means that classes
2583 // loaded by the bootstrap class loader cannot refer to classes
2584 // loaded by a user-defined class loader. Note: a user-defined
2585 // class loader can delegate to the bootstrap class loader.
2586 //
2587 // If the current class being redefined has a user-defined class
2588 // loader as its defining class loader, then we can skip all
2589 // classes loaded by the bootstrap class loader.
2590 bool is_user_defined =
2591 InstanceKlass::cast(_the_class_oop)->class_loader() != NULL;
2592 if (is_user_defined && ik->class_loader() == NULL) {
2593 return;
2594 }
2595
2596 // If the class being redefined is java.lang.Object, we need to fix all
2597 // array class vtables also
2598 if (_the_class_oop == SystemDictionary::Object_klass()) {
2599 ik->array_klasses_do(adjust_array_vtable);
2600 }
2601
2602 // This is a very busy routine. We don't want too much tracing
2603 // printed out.
2604 bool trace_name_printed = false;
2605
2606 // Very noisy: only enable this call if you are trying to determine
2607 // that a specific class gets found by this routine.
2608 // RC_TRACE macro has an embedded ResourceMark
2609 // RC_TRACE_WITH_THREAD(0x00100000, THREAD,
2610 // ("adjust check: name=%s", ik->external_name()));
2611 // trace_name_printed = true;
2612
2613 // Fix the vtable embedded in the_class and subclasses of the_class,
2614 // if one exists. We discard scratch_class and we don't keep an
2615 // InstanceKlass around to hold obsolete methods so we don't have
2616 // any other InstanceKlass embedded vtables to update. The vtable
2617 // holds the Method*s for virtual (but not final) methods.
2618 if (ik->vtable_length() > 0 && ik->is_subtype_of(_the_class_oop)) {
2619 // ik->vtable() creates a wrapper object; rm cleans it up
2620 ResourceMark rm(THREAD);
2621 ik->vtable()->adjust_method_entries(_matching_old_methods,
2622 _matching_new_methods,
2623 _matching_methods_length,
2624 &trace_name_printed);
2625 }
2626
2627 // If the current class has an itable and we are either redefining an
2628 // interface or if the current class is a subclass of the_class, then
2629 // we potentially have to fix the itable. If we are redefining an
2630 // interface, then we have to call adjust_method_entries() for
2631 // every InstanceKlass that has an itable since there isn't a
2632 // subclass relationship between an interface and an InstanceKlass.
2633 if (ik->itable_length() > 0 && (_the_class_oop->is_interface()
2634 || ik->is_subclass_of(_the_class_oop))) {
2635 // ik->itable() creates a wrapper object; rm cleans it up
2636 ResourceMark rm(THREAD);
2637 ik->itable()->adjust_method_entries(_matching_old_methods,
2638 _matching_new_methods,
2639 _matching_methods_length,
2640 &trace_name_printed);
2641 }
2642
2643 // The constant pools in other classes (other_cp) can refer to
2644 // methods in the_class. We have to update method information in
2645 // other_cp's cache. If other_cp has a previous version, then we
2646 // have to repeat the process for each previous version. The
2647 // constant pool cache holds the Method*s for non-virtual
2648 // methods and for virtual, final methods.
2649 //
2650 // Special case: if the current class is the_class, then new_cp
2651 // has already been attached to the_class and old_cp has already
2652 // been added as a previous version. The new_cp doesn't have any
2653 // cached references to old methods so it doesn't need to be
2654 // updated. We can simply start with the previous version(s) in
2655 // that case.
2656 constantPoolHandle other_cp;
2657 ConstantPoolCache* cp_cache;
2658
2659 if (k_oop != _the_class_oop) {
2660 // this klass' constant pool cache may need adjustment
2661 other_cp = constantPoolHandle(ik->constants());
2662 cp_cache = other_cp->cache();
2663 if (cp_cache != NULL) {
2664 cp_cache->adjust_method_entries(_matching_old_methods,
2665 _matching_new_methods,
2666 _matching_methods_length,
2667 &trace_name_printed);
2668 }
2669 }
2670 {
2671 ResourceMark rm(THREAD);
2672 // PreviousVersionInfo objects returned via PreviousVersionWalker
2673 // contain a GrowableArray of handles. We have to clean up the
2674 // GrowableArray _after_ the PreviousVersionWalker destructor
2675 // has destroyed the handles.
2676 {
2677 // the previous versions' constant pool caches may need adjustment
2678 PreviousVersionWalker pvw(ik);
2679 for (PreviousVersionInfo * pv_info = pvw.next_previous_version();
2680 pv_info != NULL; pv_info = pvw.next_previous_version()) {
2681 other_cp = pv_info->prev_constant_pool_handle();
2682 cp_cache = other_cp->cache();
2683 if (cp_cache != NULL) {
2684 cp_cache->adjust_method_entries(_matching_old_methods,
2685 _matching_new_methods,
2686 _matching_methods_length,
2687 &trace_name_printed);
2688 }
2689 }
2690 } // pvw is cleaned up
2691 } // rm is cleaned up
2692 }
2693 }
2694
2695 void VM_RedefineClasses::update_jmethod_ids() {
2696 for (int j = 0; j < _matching_methods_length; ++j) {
2697 Method* old_method = _matching_old_methods[j];
2698 jmethodID jmid = old_method->find_jmethod_id_or_null();
2699 if (jmid != NULL) {
2700 // There is a jmethodID, change it to point to the new method
2701 methodHandle new_method_h(_matching_new_methods[j]);
2702 Method::change_method_associated_with_jmethod_id(jmid, new_method_h());
2703 assert(Method::resolve_jmethod_id(jmid) == _matching_new_methods[j],
2704 "should be replaced");
2705 }
2706 }
2707 }
2708
2709 void VM_RedefineClasses::check_methods_and_mark_as_obsolete(
2710 BitMap *emcp_methods, int * emcp_method_count_p) {
2711 *emcp_method_count_p = 0;
2712 int obsolete_count = 0;
2713 int old_index = 0;
2714 for (int j = 0; j < _matching_methods_length; ++j, ++old_index) {
2715 Method* old_method = _matching_old_methods[j];
2716 Method* new_method = _matching_new_methods[j];
2717 Method* old_array_method;
2718
2719 // Maintain an old_index into the _old_methods array by skipping
2720 // deleted methods
2721 while ((old_array_method = _old_methods->at(old_index)) != old_method) {
2722 ++old_index;
2723 }
2724
2725 if (MethodComparator::methods_EMCP(old_method, new_method)) {
2726 // The EMCP definition from JSR-163 requires the bytecodes to be
2727 // the same with the exception of constant pool indices which may
2728 // differ. However, the constants referred to by those indices
2729 // must be the same.
2730 //
2731 // We use methods_EMCP() for comparison since constant pool
2732 // merging can remove duplicate constant pool entries that were
2733 // present in the old method and removed from the rewritten new
2734 // method. A faster binary comparison function would consider the
2735 // old and new methods to be different when they are actually
2736 // EMCP.
2737 //
2738 // The old and new methods are EMCP and you would think that we
2739 // could get rid of one of them here and now and save some space.
2740 // However, the concept of EMCP only considers the bytecodes and
2741 // the constant pool entries in the comparison. Other things,
2742 // e.g., the line number table (LNT) or the local variable table
2743 // (LVT) don't count in the comparison. So the new (and EMCP)
2744 // method can have a new LNT that we need so we can't just
2745 // overwrite the new method with the old method.
2746 //
2747 // When this routine is called, we have already attached the new
2748 // methods to the_class so the old methods are effectively
2749 // overwritten. However, if an old method is still executing,
2750 // then the old method cannot be collected until sometime after
2751 // the old method call has returned. So the overwriting of old
2752 // methods by new methods will save us space except for those
2753 // (hopefully few) old methods that are still executing.
2754 //
2755 // A method refers to a ConstMethod* and this presents another
2756 // possible avenue to space savings. The ConstMethod* in the
2757 // new method contains possibly new attributes (LNT, LVT, etc).
2758 // At first glance, it seems possible to save space by replacing
2759 // the ConstMethod* in the old method with the ConstMethod*
2760 // from the new method. The old and new methods would share the
2761 // same ConstMethod* and we would save the space occupied by
2762 // the old ConstMethod*. However, the ConstMethod* contains
2763 // a back reference to the containing method. Sharing the
2764 // ConstMethod* between two methods could lead to confusion in
2765 // the code that uses the back reference. This would lead to
2766 // brittle code that could be broken in non-obvious ways now or
2767 // in the future.
2768 //
2769 // Another possibility is to copy the ConstMethod* from the new
2770 // method to the old method and then overwrite the new method with
2771 // the old method. Since the ConstMethod* contains the bytecodes
2772 // for the method embedded in the oop, this option would change
2773 // the bytecodes out from under any threads executing the old
2774 // method and make the thread's bcp invalid. Since EMCP requires
2775 // that the bytecodes be the same modulo constant pool indices, it
2776 // is straight forward to compute the correct new bcp in the new
2777 // ConstMethod* from the old bcp in the old ConstMethod*. The
2778 // time consuming part would be searching all the frames in all
2779 // of the threads to find all of the calls to the old method.
2780 //
2781 // It looks like we will have to live with the limited savings
2782 // that we get from effectively overwriting the old methods
2783 // when the new methods are attached to the_class.
2784
2785 // track which methods are EMCP for add_previous_version() call
2786 emcp_methods->set_bit(old_index);
2787 (*emcp_method_count_p)++;
2788
2789 // An EMCP method is _not_ obsolete. An obsolete method has a
2790 // different jmethodID than the current method. An EMCP method
2791 // has the same jmethodID as the current method. Having the
2792 // same jmethodID for all EMCP versions of a method allows for
2793 // a consistent view of the EMCP methods regardless of which
2794 // EMCP method you happen to have in hand. For example, a
2795 // breakpoint set in one EMCP method will work for all EMCP
2796 // versions of the method including the current one.
2797 } else {
2798 // mark obsolete methods as such
2799 old_method->set_is_obsolete();
2800 obsolete_count++;
2801
2802 // obsolete methods need a unique idnum
2803 u2 num = InstanceKlass::cast(_the_class_oop)->next_method_idnum();
2804 if (num != ConstMethod::UNSET_IDNUM) {
2805 // u2 old_num = old_method->method_idnum();
2806 old_method->set_method_idnum(num);
2807 // TO DO: attach obsolete annotations to obsolete method's new idnum
2808 }
2809 // With tracing we try not to "yack" too much. The position of
2810 // this trace assumes there are fewer obsolete methods than
2811 // EMCP methods.
2812 RC_TRACE(0x00000100, ("mark %s(%s) as obsolete",
2813 old_method->name()->as_C_string(),
2814 old_method->signature()->as_C_string()));
2815 }
2816 old_method->set_is_old();
2817 }
2818 for (int i = 0; i < _deleted_methods_length; ++i) {
2819 Method* old_method = _deleted_methods[i];
2820
2821 assert(old_method->vtable_index() < 0,
2822 "cannot delete methods with vtable entries");;
2823
2824 // Mark all deleted methods as old and obsolete
2825 old_method->set_is_old();
2826 old_method->set_is_obsolete();
2827 ++obsolete_count;
2828 // With tracing we try not to "yack" too much. The position of
2829 // this trace assumes there are fewer obsolete methods than
2830 // EMCP methods.
2831 RC_TRACE(0x00000100, ("mark deleted %s(%s) as obsolete",
2832 old_method->name()->as_C_string(),
2833 old_method->signature()->as_C_string()));
2834 }
2835 assert((*emcp_method_count_p + obsolete_count) == _old_methods->length(),
2836 "sanity check");
2837 RC_TRACE(0x00000100, ("EMCP_cnt=%d, obsolete_cnt=%d", *emcp_method_count_p,
2838 obsolete_count));
2839 }
2840
2841 // This internal class transfers the native function registration from old methods
2842 // to new methods. It is designed to handle both the simple case of unchanged
2843 // native methods and the complex cases of native method prefixes being added and/or
2844 // removed.
2845 // It expects only to be used during the VM_RedefineClasses op (a safepoint).
2846 //
2847 // This class is used after the new methods have been installed in "the_class".
2848 //
2849 // So, for example, the following must be handled. Where 'm' is a method and
2850 // a number followed by an underscore is a prefix.
2851 //
2852 // Old Name New Name
2853 // Simple transfer to new method m -> m
2854 // Add prefix m -> 1_m
2855 // Remove prefix 1_m -> m
2856 // Simultaneous add of prefixes m -> 3_2_1_m
2857 // Simultaneous removal of prefixes 3_2_1_m -> m
2858 // Simultaneous add and remove 1_m -> 2_m
2859 // Same, caused by prefix removal only 3_2_1_m -> 3_2_m
2860 //
2861 class TransferNativeFunctionRegistration {
2862 private:
2863 instanceKlassHandle the_class;
2864 int prefix_count;
2865 char** prefixes;
2866
2867 // Recursively search the binary tree of possibly prefixed method names.
2868 // Iteration could be used if all agents were well behaved. Full tree walk is
2869 // more resilent to agents not cleaning up intermediate methods.
2870 // Branch at each depth in the binary tree is:
2871 // (1) without the prefix.
2872 // (2) with the prefix.
2873 // where 'prefix' is the prefix at that 'depth' (first prefix, second prefix,...)
2874 Method* search_prefix_name_space(int depth, char* name_str, size_t name_len,
2875 Symbol* signature) {
2876 TempNewSymbol name_symbol = SymbolTable::probe(name_str, (int)name_len);
2877 if (name_symbol != NULL) {
2878 Method* method = the_class()->lookup_method(name_symbol, signature);
2879 if (method != NULL) {
2880 // Even if prefixed, intermediate methods must exist.
2881 if (method->is_native()) {
2882 // Wahoo, we found a (possibly prefixed) version of the method, return it.
2883 return method;
2884 }
2885 if (depth < prefix_count) {
2886 // Try applying further prefixes (other than this one).
2887 method = search_prefix_name_space(depth+1, name_str, name_len, signature);
2888 if (method != NULL) {
2889 return method; // found
2890 }
2891
2892 // Try adding this prefix to the method name and see if it matches
2893 // another method name.
2894 char* prefix = prefixes[depth];
2895 size_t prefix_len = strlen(prefix);
2896 size_t trial_len = name_len + prefix_len;
2897 char* trial_name_str = NEW_RESOURCE_ARRAY(char, trial_len + 1);
2898 strcpy(trial_name_str, prefix);
2899 strcat(trial_name_str, name_str);
2900 method = search_prefix_name_space(depth+1, trial_name_str, trial_len,
2901 signature);
2902 if (method != NULL) {
2903 // If found along this branch, it was prefixed, mark as such
2904 method->set_is_prefixed_native();
2905 return method; // found
2906 }
2907 }
2908 }
2909 }
2910 return NULL; // This whole branch bore nothing
2911 }
2912
2913 // Return the method name with old prefixes stripped away.
2914 char* method_name_without_prefixes(Method* method) {
2915 Symbol* name = method->name();
2916 char* name_str = name->as_utf8();
2917
2918 // Old prefixing may be defunct, strip prefixes, if any.
2919 for (int i = prefix_count-1; i >= 0; i--) {
2920 char* prefix = prefixes[i];
2921 size_t prefix_len = strlen(prefix);
2922 if (strncmp(prefix, name_str, prefix_len) == 0) {
2923 name_str += prefix_len;
2924 }
2925 }
2926 return name_str;
2927 }
2928
2929 // Strip any prefixes off the old native method, then try to find a
2930 // (possibly prefixed) new native that matches it.
2931 Method* strip_and_search_for_new_native(Method* method) {
2932 ResourceMark rm;
2933 char* name_str = method_name_without_prefixes(method);
2934 return search_prefix_name_space(0, name_str, strlen(name_str),
2935 method->signature());
2936 }
2937
2938 public:
2939
2940 // Construct a native method transfer processor for this class.
2941 TransferNativeFunctionRegistration(instanceKlassHandle _the_class) {
2942 assert(SafepointSynchronize::is_at_safepoint(), "sanity check");
2943
2944 the_class = _the_class;
2945 prefixes = JvmtiExport::get_all_native_method_prefixes(&prefix_count);
2946 }
2947
2948 // Attempt to transfer any of the old or deleted methods that are native
2949 void transfer_registrations(Method** old_methods, int methods_length) {
2950 for (int j = 0; j < methods_length; j++) {
2951 Method* old_method = old_methods[j];
2952
2953 if (old_method->is_native() && old_method->has_native_function()) {
2954 Method* new_method = strip_and_search_for_new_native(old_method);
2955 if (new_method != NULL) {
2956 // Actually set the native function in the new method.
2957 // Redefine does not send events (except CFLH), certainly not this
2958 // behind the scenes re-registration.
2959 new_method->set_native_function(old_method->native_function(),
2960 !Method::native_bind_event_is_interesting);
2961 }
2962 }
2963 }
2964 }
2965 };
2966
2967 // Don't lose the association between a native method and its JNI function.
2968 void VM_RedefineClasses::transfer_old_native_function_registrations(instanceKlassHandle the_class) {
2969 TransferNativeFunctionRegistration transfer(the_class);
2970 transfer.transfer_registrations(_deleted_methods, _deleted_methods_length);
2971 transfer.transfer_registrations(_matching_old_methods, _matching_methods_length);
2972 }
2973
2974 // Deoptimize all compiled code that depends on this class.
2975 //
2976 // If the can_redefine_classes capability is obtained in the onload
2977 // phase then the compiler has recorded all dependencies from startup.
2978 // In that case we need only deoptimize and throw away all compiled code
2979 // that depends on the class.
2980 //
2981 // If can_redefine_classes is obtained sometime after the onload
2982 // phase then the dependency information may be incomplete. In that case
2983 // the first call to RedefineClasses causes all compiled code to be
2984 // thrown away. As can_redefine_classes has been obtained then
2985 // all future compilations will record dependencies so second and
2986 // subsequent calls to RedefineClasses need only throw away code
2987 // that depends on the class.
2988 //
2989 void VM_RedefineClasses::flush_dependent_code(instanceKlassHandle k_h, TRAPS) {
2990 assert_locked_or_safepoint(Compile_lock);
2991
2992 // All dependencies have been recorded from startup or this is a second or
2993 // subsequent use of RedefineClasses
2994 if (JvmtiExport::all_dependencies_are_recorded()) {
2995 Universe::flush_evol_dependents_on(k_h);
2996 } else {
2997 CodeCache::mark_all_nmethods_for_deoptimization();
2998
2999 ResourceMark rm(THREAD);
3000 DeoptimizationMarker dm;
3001
3002 // Deoptimize all activations depending on marked nmethods
3003 Deoptimization::deoptimize_dependents();
3004
3005 // Make the dependent methods not entrant (in VM_Deoptimize they are made zombies)
3006 CodeCache::make_marked_nmethods_not_entrant();
3007
3008 // From now on we know that the dependency information is complete
3009 JvmtiExport::set_all_dependencies_are_recorded(true);
3010 }
3011 }
3012
3013 void VM_RedefineClasses::compute_added_deleted_matching_methods() {
3014 Method* old_method;
3015 Method* new_method;
3016
3017 _matching_old_methods = NEW_RESOURCE_ARRAY(Method*, _old_methods->length());
3018 _matching_new_methods = NEW_RESOURCE_ARRAY(Method*, _old_methods->length());
3019 _added_methods = NEW_RESOURCE_ARRAY(Method*, _new_methods->length());
3020 _deleted_methods = NEW_RESOURCE_ARRAY(Method*, _old_methods->length());
3021
3022 _matching_methods_length = 0;
3023 _deleted_methods_length = 0;
3024 _added_methods_length = 0;
3025
3026 int nj = 0;
3027 int oj = 0;
3028 while (true) {
3029 if (oj >= _old_methods->length()) {
3030 if (nj >= _new_methods->length()) {
3031 break; // we've looked at everything, done
3032 }
3033 // New method at the end
3034 new_method = _new_methods->at(nj);
3035 _added_methods[_added_methods_length++] = new_method;
3036 ++nj;
3037 } else if (nj >= _new_methods->length()) {
3038 // Old method, at the end, is deleted
3039 old_method = _old_methods->at(oj);
3040 _deleted_methods[_deleted_methods_length++] = old_method;
3041 ++oj;
3042 } else {
3043 old_method = _old_methods->at(oj);
3044 new_method = _new_methods->at(nj);
3045 if (old_method->name() == new_method->name()) {
3046 if (old_method->signature() == new_method->signature()) {
3047 _matching_old_methods[_matching_methods_length ] = old_method;
3048 _matching_new_methods[_matching_methods_length++] = new_method;
3049 ++nj;
3050 ++oj;
3051 } else {
3052 // added overloaded have already been moved to the end,
3053 // so this is a deleted overloaded method
3054 _deleted_methods[_deleted_methods_length++] = old_method;
3055 ++oj;
3056 }
3057 } else { // names don't match
3058 if (old_method->name()->fast_compare(new_method->name()) > 0) {
3059 // new method
3060 _added_methods[_added_methods_length++] = new_method;
3061 ++nj;
3062 } else {
3063 // deleted method
3064 _deleted_methods[_deleted_methods_length++] = old_method;
3065 ++oj;
3066 }
3067 }
3068 }
3069 }
3070 assert(_matching_methods_length + _deleted_methods_length == _old_methods->length(), "sanity");
3071 assert(_matching_methods_length + _added_methods_length == _new_methods->length(), "sanity");
3072 }
3073
3074
3075
3076 // Install the redefinition of a class:
3077 // - house keeping (flushing breakpoints and caches, deoptimizing
3078 // dependent compiled code)
3079 // - replacing parts in the_class with parts from scratch_class
3080 // - adding a weak reference to track the obsolete but interesting
3081 // parts of the_class
3082 // - adjusting constant pool caches and vtables in other classes
3083 // that refer to methods in the_class. These adjustments use the
3084 // SystemDictionary::classes_do() facility which only allows
3085 // a helper method to be specified. The interesting parameters
3086 // that we would like to pass to the helper method are saved in
3087 // static global fields in the VM operation.
3088 void VM_RedefineClasses::redefine_single_class(jclass the_jclass,
3089 Klass* scratch_class_oop, TRAPS) {
3090
3091 HandleMark hm(THREAD); // make sure handles from this call are freed
3092 RC_TIMER_START(_timer_rsc_phase1);
3093
3094 instanceKlassHandle scratch_class(scratch_class_oop);
3095
3096 oop the_class_mirror = JNIHandles::resolve_non_null(the_jclass);
3097 Klass* the_class_oop = java_lang_Class::as_Klass(the_class_mirror);
3098 instanceKlassHandle the_class = instanceKlassHandle(THREAD, the_class_oop);
3099
3100 // Remove all breakpoints in methods of this class
3101 JvmtiBreakpoints& jvmti_breakpoints = JvmtiCurrentBreakpoints::get_jvmti_breakpoints();
3102 jvmti_breakpoints.clearall_in_class_at_safepoint(the_class_oop);
3103
3104 if (the_class_oop == Universe::reflect_invoke_cache()->klass()) {
3105 // We are redefining java.lang.reflect.Method. Method.invoke() is
3106 // cached and users of the cache care about each active version of
3107 // the method so we have to track this previous version.
3108 // Do this before methods get switched
3109 Universe::reflect_invoke_cache()->add_previous_version(
3110 the_class->method_with_idnum(Universe::reflect_invoke_cache()->method_idnum()));
3111 }
3112
3113 // Deoptimize all compiled code that depends on this class
3114 flush_dependent_code(the_class, THREAD);
3115
3116 _old_methods = the_class->methods();
3117 _new_methods = scratch_class->methods();
3118 _the_class_oop = the_class_oop;
3119 compute_added_deleted_matching_methods();
3120 update_jmethod_ids();
3121
3122 // Attach new constant pool to the original klass. The original
3123 // klass still refers to the old constant pool (for now).
3124 scratch_class->constants()->set_pool_holder(the_class());
3125
3126 #if 0
3127 // In theory, with constant pool merging in place we should be able
3128 // to save space by using the new, merged constant pool in place of
3129 // the old constant pool(s). By "pool(s)" I mean the constant pool in
3130 // the klass version we are replacing now and any constant pool(s) in
3131 // previous versions of klass. Nice theory, doesn't work in practice.
3132 // When this code is enabled, even simple programs throw NullPointer
3133 // exceptions. I'm guessing that this is caused by some constant pool
3134 // cache difference between the new, merged constant pool and the
3135 // constant pool that was just being used by the klass. I'm keeping
3136 // this code around to archive the idea, but the code has to remain
3137 // disabled for now.
3138
3139 // Attach each old method to the new constant pool. This can be
3140 // done here since we are past the bytecode verification and
3141 // constant pool optimization phases.
3142 for (int i = _old_methods->length() - 1; i >= 0; i--) {
3143 Method* method = _old_methods->at(i);
3144 method->set_constants(scratch_class->constants());
3145 }
3146
3147 {
3148 // walk all previous versions of the klass
3149 InstanceKlass *ik = (InstanceKlass *)the_class();
3150 PreviousVersionWalker pvw(ik);
3151 instanceKlassHandle ikh;
3152 do {
3153 ikh = pvw.next_previous_version();
3154 if (!ikh.is_null()) {
3155 ik = ikh();
3156
3157 // attach previous version of klass to the new constant pool
3158 ik->set_constants(scratch_class->constants());
3159
3160 // Attach each method in the previous version of klass to the
3161 // new constant pool
3162 Array<Method*>* prev_methods = ik->methods();
3163 for (int i = prev_methods->length() - 1; i >= 0; i--) {
3164 Method* method = prev_methods->at(i);
3165 method->set_constants(scratch_class->constants());
3166 }
3167 }
3168 } while (!ikh.is_null());
3169 }
3170 #endif
3171
3172 // Replace methods and constantpool
3173 the_class->set_methods(_new_methods);
3174 scratch_class->set_methods(_old_methods); // To prevent potential GCing of the old methods,
3175 // and to be able to undo operation easily.
3176
3177 ConstantPool* old_constants = the_class->constants();
3178 the_class->set_constants(scratch_class->constants());
3179 scratch_class->set_constants(old_constants); // See the previous comment.
3180 #if 0
3181 // We are swapping the guts of "the new class" with the guts of "the
3182 // class". Since the old constant pool has just been attached to "the
3183 // new class", it seems logical to set the pool holder in the old
3184 // constant pool also. However, doing this will change the observable
3185 // class hierarchy for any old methods that are still executing. A
3186 // method can query the identity of its "holder" and this query uses
3187 // the method's constant pool link to find the holder. The change in
3188 // holding class from "the class" to "the new class" can confuse
3189 // things.
3190 //
3191 // Setting the old constant pool's holder will also cause
3192 // verification done during vtable initialization below to fail.
3193 // During vtable initialization, the vtable's class is verified to be
3194 // a subtype of the method's holder. The vtable's class is "the
3195 // class" and the method's holder is gotten from the constant pool
3196 // link in the method itself. For "the class"'s directly implemented
3197 // methods, the method holder is "the class" itself (as gotten from
3198 // the new constant pool). The check works fine in this case. The
3199 // check also works fine for methods inherited from super classes.
3200 //
3201 // Miranda methods are a little more complicated. A miranda method is
3202 // provided by an interface when the class implementing the interface
3203 // does not provide its own method. These interfaces are implemented
3204 // internally as an InstanceKlass. These special instanceKlasses
3205 // share the constant pool of the class that "implements" the
3206 // interface. By sharing the constant pool, the method holder of a
3207 // miranda method is the class that "implements" the interface. In a
3208 // non-redefine situation, the subtype check works fine. However, if
3209 // the old constant pool's pool holder is modified, then the check
3210 // fails because there is no class hierarchy relationship between the
3211 // vtable's class and "the new class".
3212
3213 old_constants->set_pool_holder(scratch_class());
3214 #endif
3215
3216 // track which methods are EMCP for add_previous_version() call below
3217 BitMap emcp_methods(_old_methods->length());
3218 int emcp_method_count = 0;
3219 emcp_methods.clear(); // clears 0..(length() - 1)
3220 check_methods_and_mark_as_obsolete(&emcp_methods, &emcp_method_count);
3221 transfer_old_native_function_registrations(the_class);
3222
3223 // The class file bytes from before any retransformable agents mucked
3224 // with them was cached on the scratch class, move to the_class.
3225 // Note: we still want to do this if nothing needed caching since it
3226 // should get cleared in the_class too.
3227 if (the_class->get_cached_class_file_bytes() == 0) {
3228 // the_class doesn't have a cache yet so copy it
3229 the_class->set_cached_class_file(
3230 scratch_class->get_cached_class_file_bytes(),
3231 scratch_class->get_cached_class_file_len());
3232 }
3233 #ifndef PRODUCT
3234 else {
3235 assert(the_class->get_cached_class_file_bytes() ==
3236 scratch_class->get_cached_class_file_bytes(), "cache ptrs must match");
3237 assert(the_class->get_cached_class_file_len() ==
3238 scratch_class->get_cached_class_file_len(), "cache lens must match");
3239 }
3240 #endif
3241
3242 // Replace inner_classes
3243 Array<u2>* old_inner_classes = the_class->inner_classes();
3244 the_class->set_inner_classes(scratch_class->inner_classes());
3245 scratch_class->set_inner_classes(old_inner_classes);
3246
3247 // Initialize the vtable and interface table after
3248 // methods have been rewritten
3249 {
3250 ResourceMark rm(THREAD);
3251 // no exception should happen here since we explicitly
3252 // do not check loader constraints.
3253 // compare_and_normalize_class_versions has already checked:
3254 // - classloaders unchanged, signatures unchanged
3255 // - all instanceKlasses for redefined classes reused & contents updated
3256 the_class->vtable()->initialize_vtable(false, THREAD);
3257 the_class->itable()->initialize_itable(false, THREAD);
3258 assert(!HAS_PENDING_EXCEPTION || (THREAD->pending_exception()->is_a(SystemDictionary::ThreadDeath_klass())), "redefine exception");
3259 }
3260
3261 // Leave arrays of jmethodIDs and itable index cache unchanged
3262
3263 // Copy the "source file name" attribute from new class version
3264 the_class->set_source_file_name(scratch_class->source_file_name());
3265
3266 // Copy the "source debug extension" attribute from new class version
3267 the_class->set_source_debug_extension(
3268 scratch_class->source_debug_extension(),
3269 scratch_class->source_debug_extension() == NULL ? 0 :
3270 (int)strlen(scratch_class->source_debug_extension()));
3271
3272 // Use of javac -g could be different in the old and the new
3273 if (scratch_class->access_flags().has_localvariable_table() !=
3274 the_class->access_flags().has_localvariable_table()) {
3275
3276 AccessFlags flags = the_class->access_flags();
3277 if (scratch_class->access_flags().has_localvariable_table()) {
3278 flags.set_has_localvariable_table();
3279 } else {
3280 flags.clear_has_localvariable_table();
3281 }
3282 the_class->set_access_flags(flags);
3283 }
3284
3285 // Since there is currently no rewriting of type annotations indexes
3286 // into the CP, we null out type annotations on scratch_class before
3287 // we swap annotations with the_class rather than facing the
3288 // possibility of shipping annotations with broken indexes to
3289 // Java-land.
3290 Annotations* new_annotations = scratch_class->annotations();
3291 if (new_annotations != NULL) {
3292 Annotations* new_type_annotations = new_annotations->type_annotations();
3293 if (new_type_annotations != NULL) {
3294 MetadataFactory::free_metadata(scratch_class->class_loader_data(), new_type_annotations);
3295 new_annotations->set_type_annotations(NULL);
3296 }
3297 }
3298 // Swap annotation fields values
3299 Annotations* old_annotations = the_class->annotations();
3300 the_class->set_annotations(scratch_class->annotations());
3301 scratch_class->set_annotations(old_annotations);
3302
3303 // Replace minor version number of class file
3304 u2 old_minor_version = the_class->minor_version();
3305 the_class->set_minor_version(scratch_class->minor_version());
3306 scratch_class->set_minor_version(old_minor_version);
3307
3308 // Replace major version number of class file
3309 u2 old_major_version = the_class->major_version();
3310 the_class->set_major_version(scratch_class->major_version());
3311 scratch_class->set_major_version(old_major_version);
3312
3313 // Replace CP indexes for class and name+type of enclosing method
3314 u2 old_class_idx = the_class->enclosing_method_class_index();
3315 u2 old_method_idx = the_class->enclosing_method_method_index();
3316 the_class->set_enclosing_method_indices(
3317 scratch_class->enclosing_method_class_index(),
3318 scratch_class->enclosing_method_method_index());
3319 scratch_class->set_enclosing_method_indices(old_class_idx, old_method_idx);
3320
3321 // keep track of previous versions of this class
3322 the_class->add_previous_version(scratch_class, &emcp_methods,
3323 emcp_method_count);
3324
3325 RC_TIMER_STOP(_timer_rsc_phase1);
3326 RC_TIMER_START(_timer_rsc_phase2);
3327
3328 // Adjust constantpool caches and vtables for all classes
3329 // that reference methods of the evolved class.
3330 SystemDictionary::classes_do(adjust_cpool_cache_and_vtable, THREAD);
3331
3332 // Fix Resolution Error table also to remove old constant pools
3333 SystemDictionary::delete_resolution_error(old_constants);
3334
3335 if (the_class->oop_map_cache() != NULL) {
3336 // Flush references to any obsolete methods from the oop map cache
3337 // so that obsolete methods are not pinned.
3338 the_class->oop_map_cache()->flush_obsolete_entries();
3339 }
3340
3341 // increment the classRedefinedCount field in the_class and in any
3342 // direct and indirect subclasses of the_class
3343 increment_class_counter((InstanceKlass *)the_class(), THREAD);
3344
3345 // RC_TRACE macro has an embedded ResourceMark
3346 RC_TRACE_WITH_THREAD(0x00000001, THREAD,
3347 ("redefined name=%s, count=%d (avail_mem=" UINT64_FORMAT "K)",
3348 the_class->external_name(),
3349 java_lang_Class::classRedefinedCount(the_class_mirror),
3350 os::available_memory() >> 10));
3351
3352 RC_TIMER_STOP(_timer_rsc_phase2);
3353 } // end redefine_single_class()
3354
3355
3356 // Increment the classRedefinedCount field in the specific InstanceKlass
3357 // and in all direct and indirect subclasses.
3358 void VM_RedefineClasses::increment_class_counter(InstanceKlass *ik, TRAPS) {
3359 oop class_mirror = ik->java_mirror();
3360 Klass* class_oop = java_lang_Class::as_Klass(class_mirror);
3361 int new_count = java_lang_Class::classRedefinedCount(class_mirror) + 1;
3362 java_lang_Class::set_classRedefinedCount(class_mirror, new_count);
3363
3364 if (class_oop != _the_class_oop) {
3365 // _the_class_oop count is printed at end of redefine_single_class()
3366 RC_TRACE_WITH_THREAD(0x00000008, THREAD,
3367 ("updated count in subclass=%s to %d", ik->external_name(), new_count));
3368 }
3369
3370 for (Klass *subk = ik->subklass(); subk != NULL;
3371 subk = subk->next_sibling()) {
3372 if (subk->oop_is_instance()) {
3373 // Only update instanceKlasses
3374 InstanceKlass *subik = (InstanceKlass*)subk;
3375 // recursively do subclasses of the current subclass
3376 increment_class_counter(subik, THREAD);
3377 }
3378 }
3379 }
3380
3381 void VM_RedefineClasses::check_class(Klass* k_oop,
3382 ClassLoaderData* initiating_loader,
3383 TRAPS) {
3384 Klass *k = k_oop;
3385 if (k->oop_is_instance()) {
3386 HandleMark hm(THREAD);
3387 InstanceKlass *ik = (InstanceKlass *) k;
3388 bool no_old_methods = true; // be optimistic
3389 ResourceMark rm(THREAD);
3390
3391 // a vtable should never contain old or obsolete methods
3392 if (ik->vtable_length() > 0 &&
3393 !ik->vtable()->check_no_old_or_obsolete_entries()) {
3394 if (RC_TRACE_ENABLED(0x00004000)) {
3395 RC_TRACE_WITH_THREAD(0x00004000, THREAD,
3396 ("klassVtable::check_no_old_or_obsolete_entries failure"
3397 " -- OLD or OBSOLETE method found -- class: %s",
3398 ik->signature_name()));
3399 ik->vtable()->dump_vtable();
3400 }
3401 no_old_methods = false;
3402 }
3403
3404 // an itable should never contain old or obsolete methods
3405 if (ik->itable_length() > 0 &&
3406 !ik->itable()->check_no_old_or_obsolete_entries()) {
3407 if (RC_TRACE_ENABLED(0x00004000)) {
3408 RC_TRACE_WITH_THREAD(0x00004000, THREAD,
3409 ("klassItable::check_no_old_or_obsolete_entries failure"
3410 " -- OLD or OBSOLETE method found -- class: %s",
3411 ik->signature_name()));
3412 ik->itable()->dump_itable();
3413 }
3414 no_old_methods = false;
3415 }
3416
3417 // the constant pool cache should never contain old or obsolete methods
3418 if (ik->constants() != NULL &&
3419 ik->constants()->cache() != NULL &&
3420 !ik->constants()->cache()->check_no_old_or_obsolete_entries()) {
3421 if (RC_TRACE_ENABLED(0x00004000)) {
3422 RC_TRACE_WITH_THREAD(0x00004000, THREAD,
3423 ("cp-cache::check_no_old_or_obsolete_entries failure"
3424 " -- OLD or OBSOLETE method found -- class: %s",
3425 ik->signature_name()));
3426 ik->constants()->cache()->dump_cache();
3427 }
3428 no_old_methods = false;
3429 }
3430
3431 if (!no_old_methods) {
3432 if (RC_TRACE_ENABLED(0x00004000)) {
3433 dump_methods();
3434 } else {
3435 tty->print_cr("INFO: use the '-XX:TraceRedefineClasses=16384' option "
3436 "to see more info about the following guarantee() failure.");
3437 }
3438 guarantee(false, "OLD and/or OBSOLETE method(s) found");
3439 }
3440 }
3441 }
3442
3443 void VM_RedefineClasses::dump_methods() {
3444 int j;
3445 RC_TRACE(0x00004000, ("_old_methods --"));
3446 for (j = 0; j < _old_methods->length(); ++j) {
3447 Method* m = _old_methods->at(j);
3448 RC_TRACE_NO_CR(0x00004000, ("%4d (%5d) ", j, m->vtable_index()));
3449 m->access_flags().print_on(tty);
3450 tty->print(" -- ");
3451 m->print_name(tty);
3452 tty->cr();
3453 }
3454 RC_TRACE(0x00004000, ("_new_methods --"));
3455 for (j = 0; j < _new_methods->length(); ++j) {
3456 Method* m = _new_methods->at(j);
3457 RC_TRACE_NO_CR(0x00004000, ("%4d (%5d) ", j, m->vtable_index()));
3458 m->access_flags().print_on(tty);
3459 tty->print(" -- ");
3460 m->print_name(tty);
3461 tty->cr();
3462 }
3463 RC_TRACE(0x00004000, ("_matching_(old/new)_methods --"));
3464 for (j = 0; j < _matching_methods_length; ++j) {
3465 Method* m = _matching_old_methods[j];
3466 RC_TRACE_NO_CR(0x00004000, ("%4d (%5d) ", j, m->vtable_index()));
3467 m->access_flags().print_on(tty);
3468 tty->print(" -- ");
3469 m->print_name(tty);
3470 tty->cr();
3471 m = _matching_new_methods[j];
3472 RC_TRACE_NO_CR(0x00004000, (" (%5d) ", m->vtable_index()));
3473 m->access_flags().print_on(tty);
3474 tty->cr();
3475 }
3476 RC_TRACE(0x00004000, ("_deleted_methods --"));
3477 for (j = 0; j < _deleted_methods_length; ++j) {
3478 Method* m = _deleted_methods[j];
3479 RC_TRACE_NO_CR(0x00004000, ("%4d (%5d) ", j, m->vtable_index()));
3480 m->access_flags().print_on(tty);
3481 tty->print(" -- ");
3482 m->print_name(tty);
3483 tty->cr();
3484 }
3485 RC_TRACE(0x00004000, ("_added_methods --"));
3486 for (j = 0; j < _added_methods_length; ++j) {
3487 Method* m = _added_methods[j];
3488 RC_TRACE_NO_CR(0x00004000, ("%4d (%5d) ", j, m->vtable_index()));
3489 m->access_flags().print_on(tty);
3490 tty->print(" -- ");
3491 m->print_name(tty);
3492 tty->cr();
3493 }
3494 }