1 /*
2 * Copyright (c) 1997, 2025, 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 "cds/aotConstantPoolResolver.hpp"
26 #include "cds/archiveBuilder.hpp"
27 #include "cds/archiveHeapLoader.hpp"
28 #include "cds/archiveHeapWriter.hpp"
29 #include "cds/cdsConfig.hpp"
30 #include "cds/heapShared.hpp"
31 #include "classfile/classLoader.hpp"
32 #include "classfile/classLoaderData.hpp"
33 #include "classfile/javaClasses.inline.hpp"
34 #include "classfile/metadataOnStackMark.hpp"
35 #include "classfile/stringTable.hpp"
36 #include "classfile/systemDictionary.hpp"
37 #include "classfile/systemDictionaryShared.hpp"
38 #include "classfile/vmClasses.hpp"
39 #include "classfile/vmSymbols.hpp"
40 #include "code/codeCache.hpp"
41 #include "interpreter/bootstrapInfo.hpp"
42 #include "interpreter/linkResolver.hpp"
43 #include "jvm.h"
44 #include "logging/log.hpp"
45 #include "logging/logStream.hpp"
46 #include "memory/allocation.inline.hpp"
47 #include "memory/metadataFactory.hpp"
48 #include "memory/metaspaceClosure.hpp"
49 #include "memory/oopFactory.hpp"
50 #include "memory/resourceArea.hpp"
51 #include "memory/universe.hpp"
52 #include "oops/array.hpp"
53 #include "oops/constantPool.inline.hpp"
54 #include "oops/cpCache.inline.hpp"
55 #include "oops/fieldStreams.inline.hpp"
56 #include "oops/flatArrayKlass.hpp"
57 #include "oops/instanceKlass.hpp"
58 #include "oops/klass.inline.hpp"
59 #include "oops/objArrayKlass.hpp"
60 #include "oops/objArrayOop.inline.hpp"
61 #include "oops/oop.inline.hpp"
62 #include "oops/typeArrayOop.inline.hpp"
63 #include "prims/jvmtiExport.hpp"
64 #include "runtime/atomic.hpp"
65 #include "runtime/fieldDescriptor.inline.hpp"
66 #include "runtime/handles.inline.hpp"
67 #include "runtime/init.hpp"
68 #include "runtime/javaCalls.hpp"
69 #include "runtime/javaThread.inline.hpp"
70 #include "runtime/perfData.hpp"
71 #include "runtime/signature.hpp"
72 #include "runtime/vframe.inline.hpp"
73 #include "utilities/checkedCast.hpp"
74 #include "utilities/copy.hpp"
75
76 ConstantPool* ConstantPool::allocate(ClassLoaderData* loader_data, int length, TRAPS) {
77 Array<u1>* tags = MetadataFactory::new_array<u1>(loader_data, length, 0, CHECK_NULL);
78 int size = ConstantPool::size(length);
79 return new (loader_data, size, MetaspaceObj::ConstantPoolType, THREAD) ConstantPool(tags);
80 }
81
82 void ConstantPool::copy_fields(const ConstantPool* orig) {
83 // Preserve dynamic constant information from the original pool
84 if (orig->has_dynamic_constant()) {
85 set_has_dynamic_constant();
86 }
87
88 set_major_version(orig->major_version());
89 set_minor_version(orig->minor_version());
90
91 set_source_file_name_index(orig->source_file_name_index());
92 set_generic_signature_index(orig->generic_signature_index());
93 }
94
95 #ifdef ASSERT
96
97 // MetaspaceObj allocation invariant is calloc equivalent memory
98 // simple verification of this here (JVM_CONSTANT_Invalid == 0 )
99 static bool tag_array_is_zero_initialized(Array<u1>* tags) {
100 assert(tags != nullptr, "invariant");
101 const int length = tags->length();
102 for (int index = 0; index < length; ++index) {
103 if (JVM_CONSTANT_Invalid != tags->at(index)) {
104 return false;
105 }
106 }
107 return true;
108 }
109
110 #endif
111
112 ConstantPool::ConstantPool() {
113 assert(CDSConfig::is_dumping_static_archive() || CDSConfig::is_using_archive(), "only for CDS");
114 }
115
116 ConstantPool::ConstantPool(Array<u1>* tags) :
117 _tags(tags),
118 _length(tags->length()) {
119
120 assert(_tags != nullptr, "invariant");
121 assert(tags->length() == _length, "invariant");
122 assert(tag_array_is_zero_initialized(tags), "invariant");
123 assert(0 == flags(), "invariant");
124 assert(0 == version(), "invariant");
125 assert(nullptr == _pool_holder, "invariant");
126 }
127
128 void ConstantPool::deallocate_contents(ClassLoaderData* loader_data) {
129 if (cache() != nullptr) {
130 MetadataFactory::free_metadata(loader_data, cache());
131 set_cache(nullptr);
132 }
133
134 MetadataFactory::free_array<Klass*>(loader_data, resolved_klasses());
135 set_resolved_klasses(nullptr);
136
137 MetadataFactory::free_array<jushort>(loader_data, operands());
138 set_operands(nullptr);
139
140 release_C_heap_structures();
141
142 // free tag array
143 MetadataFactory::free_array<u1>(loader_data, tags());
144 set_tags(nullptr);
145 }
146
147 void ConstantPool::release_C_heap_structures() {
148 // walk constant pool and decrement symbol reference counts
149 unreference_symbols();
150 }
151
152 void ConstantPool::metaspace_pointers_do(MetaspaceClosure* it) {
153 log_trace(cds)("Iter(ConstantPool): %p", this);
154
155 it->push(&_tags, MetaspaceClosure::_writable);
156 it->push(&_cache);
157 it->push(&_pool_holder);
158 it->push(&_operands);
159 it->push(&_resolved_klasses, MetaspaceClosure::_writable);
160
161 for (int i = 0; i < length(); i++) {
162 // The only MSO's embedded in the CP entries are Symbols:
163 // JVM_CONSTANT_String
164 // JVM_CONSTANT_Utf8
165 constantTag ctag = tag_at(i);
166 if (ctag.is_string() || ctag.is_utf8()) {
167 it->push(symbol_at_addr(i));
168 }
169 }
170 }
171
172 objArrayOop ConstantPool::resolved_references() const {
173 return _cache->resolved_references();
174 }
175
176 // Called from outside constant pool resolution where a resolved_reference array
177 // may not be present.
178 objArrayOop ConstantPool::resolved_references_or_null() const {
179 if (_cache == nullptr) {
180 return nullptr;
181 } else {
182 return _cache->resolved_references();
183 }
184 }
185
186 oop ConstantPool::resolved_reference_at(int index) const {
187 oop result = resolved_references()->obj_at(index);
188 assert(oopDesc::is_oop_or_null(result), "Must be oop");
189 return result;
190 }
191
192 // Use a CAS for multithreaded access
193 oop ConstantPool::set_resolved_reference_at(int index, oop new_result) {
194 assert(oopDesc::is_oop_or_null(new_result), "Must be oop");
195 return resolved_references()->replace_if_null(index, new_result);
196 }
197
198 // Create resolved_references array and mapping array for original cp indexes
199 // The ldc bytecode was rewritten to have the resolved reference array index so need a way
200 // to map it back for resolving and some unlikely miscellaneous uses.
201 // The objects created by invokedynamic are appended to this list.
202 void ConstantPool::initialize_resolved_references(ClassLoaderData* loader_data,
203 const intStack& reference_map,
204 int constant_pool_map_length,
205 TRAPS) {
206 // Initialized the resolved object cache.
207 int map_length = reference_map.length();
208 if (map_length > 0) {
209 // Only need mapping back to constant pool entries. The map isn't used for
210 // invokedynamic resolved_reference entries. For invokedynamic entries,
211 // the constant pool cache index has the mapping back to both the constant
212 // pool and to the resolved reference index.
213 if (constant_pool_map_length > 0) {
214 Array<u2>* om = MetadataFactory::new_array<u2>(loader_data, constant_pool_map_length, CHECK);
215
216 for (int i = 0; i < constant_pool_map_length; i++) {
217 int x = reference_map.at(i);
218 assert(x == (int)(jushort) x, "klass index is too big");
219 om->at_put(i, (jushort)x);
220 }
221 set_reference_map(om);
222 }
223
224 // Create Java array for holding resolved strings, methodHandles,
225 // methodTypes, invokedynamic and invokehandle appendix objects, etc.
226 objArrayOop stom = oopFactory::new_objArray(vmClasses::Object_klass(), map_length, CHECK);
227 HandleMark hm(THREAD);
228 Handle refs_handle (THREAD, stom); // must handleize.
229 set_resolved_references(loader_data->add_handle(refs_handle));
230
231 // Create a "scratch" copy of the resolved references array to archive
232 if (CDSConfig::is_dumping_heap()) {
233 objArrayOop scratch_references = oopFactory::new_objArray(vmClasses::Object_klass(), map_length, CHECK);
234 HeapShared::add_scratch_resolved_references(this, scratch_references);
235 }
236 }
237 }
238
239 void ConstantPool::allocate_resolved_klasses(ClassLoaderData* loader_data, int num_klasses, TRAPS) {
240 // A ConstantPool can't possibly have 0xffff valid class entries,
241 // because entry #0 must be CONSTANT_Invalid, and each class entry must refer to a UTF8
242 // entry for the class's name. So at most we will have 0xfffe class entries.
243 // This allows us to use 0xffff (ConstantPool::_temp_resolved_klass_index) to indicate
244 // UnresolvedKlass entries that are temporarily created during class redefinition.
245 assert(num_klasses < CPKlassSlot::_temp_resolved_klass_index, "sanity");
246 assert(resolved_klasses() == nullptr, "sanity");
247 Array<Klass*>* rk = MetadataFactory::new_array<Klass*>(loader_data, num_klasses, CHECK);
248 set_resolved_klasses(rk);
249 }
250
251 void ConstantPool::initialize_unresolved_klasses(ClassLoaderData* loader_data, TRAPS) {
252 int len = length();
253 int num_klasses = 0;
254 for (int i = 1; i <len; i++) {
255 switch (tag_at(i).value()) {
256 case JVM_CONSTANT_ClassIndex:
257 {
258 const int class_index = klass_index_at(i);
259 unresolved_klass_at_put(i, class_index, num_klasses++);
260 }
261 break;
262 #ifndef PRODUCT
263 case JVM_CONSTANT_Class:
264 case JVM_CONSTANT_UnresolvedClass:
265 case JVM_CONSTANT_UnresolvedClassInError:
266 // All of these should have been reverted back to Unresolved before calling
267 // this function.
268 ShouldNotReachHere();
269 #endif
270 }
271 }
272 allocate_resolved_klasses(loader_data, num_klasses, THREAD);
273 }
274
275 // Hidden class support:
276 void ConstantPool::klass_at_put(int class_index, Klass* k) {
277 assert(k != nullptr, "must be valid klass");
278 CPKlassSlot kslot = klass_slot_at(class_index);
279 int resolved_klass_index = kslot.resolved_klass_index();
280 Klass** adr = resolved_klasses()->adr_at(resolved_klass_index);
281 Atomic::release_store(adr, k);
282
283 // The interpreter assumes when the tag is stored, the klass is resolved
284 // and the Klass* non-null, so we need hardware store ordering here.
285 release_tag_at_put(class_index, JVM_CONSTANT_Class);
286 }
287
288 #if INCLUDE_CDS_JAVA_HEAP
289 template <typename Function>
290 void ConstantPool::iterate_archivable_resolved_references(Function function) {
291 objArrayOop rr = resolved_references();
292 if (rr != nullptr && cache() != nullptr && CDSConfig::is_dumping_method_handles()) {
293 Array<ResolvedIndyEntry>* indy_entries = cache()->resolved_indy_entries();
294 if (indy_entries != nullptr) {
295 for (int i = 0; i < indy_entries->length(); i++) {
296 ResolvedIndyEntry *rie = indy_entries->adr_at(i);
297 if (rie->is_resolved() && AOTConstantPoolResolver::is_resolution_deterministic(this, rie->constant_pool_index())) {
298 int rr_index = rie->resolved_references_index();
299 assert(resolved_reference_at(rr_index) != nullptr, "must exist");
300 function(rr_index);
301
302 // Save the BSM as well (sometimes the JIT looks up the BSM it for replay)
303 int indy_cp_index = rie->constant_pool_index();
304 int bsm_mh_cp_index = bootstrap_method_ref_index_at(indy_cp_index);
305 int bsm_rr_index = cp_to_object_index(bsm_mh_cp_index);
306 assert(resolved_reference_at(bsm_rr_index) != nullptr, "must exist");
307 function(bsm_rr_index);
308 }
309 }
310 }
311
312 Array<ResolvedMethodEntry>* method_entries = cache()->resolved_method_entries();
313 if (method_entries != nullptr) {
314 for (int i = 0; i < method_entries->length(); i++) {
315 ResolvedMethodEntry* rme = method_entries->adr_at(i);
316 if (rme->is_resolved(Bytecodes::_invokehandle) && rme->has_appendix() &&
317 cache()->can_archive_resolved_method(this, rme)) {
318 int rr_index = rme->resolved_references_index();
319 assert(resolved_reference_at(rr_index) != nullptr, "must exist");
320 function(rr_index);
321 }
322 }
323 }
324 }
325 }
326
327 // Returns the _resolved_reference array after removing unarchivable items from it.
328 // Returns null if this class is not supported, or _resolved_reference doesn't exist.
329 objArrayOop ConstantPool::prepare_resolved_references_for_archiving() {
330 if (_cache == nullptr) {
331 return nullptr; // nothing to do
332 }
333
334 InstanceKlass *ik = pool_holder();
335 if (!SystemDictionaryShared::is_builtin_loader(ik->class_loader_data())) {
336 // Archiving resolved references for classes from non-builtin loaders
337 // is not yet supported.
338 return nullptr;
339 }
340
341 objArrayOop rr = resolved_references();
342 if (rr != nullptr) {
343 ResourceMark rm;
344 int rr_len = rr->length();
345 GrowableArray<bool> keep_resolved_refs(rr_len, rr_len, false);
346
347 iterate_archivable_resolved_references([&](int rr_index) {
348 keep_resolved_refs.at_put(rr_index, true);
349 });
350
351 objArrayOop scratch_rr = HeapShared::scratch_resolved_references(this);
352 Array<u2>* ref_map = reference_map();
353 int ref_map_len = ref_map == nullptr ? 0 : ref_map->length();
354 for (int i = 0; i < rr_len; i++) {
355 oop obj = rr->obj_at(i);
356 scratch_rr->obj_at_put(i, nullptr);
357 if (obj != nullptr) {
358 if (i < ref_map_len) {
359 int index = object_to_cp_index(i);
360 if (tag_at(index).is_string()) {
361 assert(java_lang_String::is_instance(obj), "must be");
362 if (!ArchiveHeapWriter::is_string_too_large_to_archive(obj)) {
363 scratch_rr->obj_at_put(i, obj);
364 }
365 continue;
366 }
367 }
368
369 if (keep_resolved_refs.at(i)) {
370 scratch_rr->obj_at_put(i, obj);
371 }
372 }
373 }
374 return scratch_rr;
375 }
376 return rr;
377 }
378
379 void ConstantPool::add_dumped_interned_strings() {
380 InstanceKlass* ik = pool_holder();
381 if (!ik->is_linked()) {
382 // resolved_references() doesn't exist yet, so we have no resolved CONSTANT_String entries. However,
383 // some static final fields may have default values that were initialized when the class was parsed.
384 // We need to enter those into the CDS archive strings table.
385 for (JavaFieldStream fs(ik); !fs.done(); fs.next()) {
386 if (fs.access_flags().is_static()) {
387 fieldDescriptor& fd = fs.field_descriptor();
388 if (fd.field_type() == T_OBJECT) {
389 int offset = fd.offset();
390 check_and_add_dumped_interned_string(ik->java_mirror()->obj_field(offset));
391 }
392 }
393 }
394 } else {
395 objArrayOop rr = resolved_references();
396 if (rr != nullptr) {
397 int rr_len = rr->length();
398 for (int i = 0; i < rr_len; i++) {
399 check_and_add_dumped_interned_string(rr->obj_at(i));
400 }
401 }
402 }
403 }
404
405 void ConstantPool::check_and_add_dumped_interned_string(oop obj) {
406 if (obj != nullptr && java_lang_String::is_instance(obj) &&
407 !ArchiveHeapWriter::is_string_too_large_to_archive(obj)) {
408 HeapShared::add_to_dumped_interned_strings(obj);
409 }
410 }
411
412 #endif
413
414 #if INCLUDE_CDS
415 // CDS support. Create a new resolved_references array.
416 void ConstantPool::restore_unshareable_info(TRAPS) {
417 if (!_pool_holder->is_linked() && !_pool_holder->is_rewritten()) {
418 return;
419 }
420 assert(is_constantPool(), "ensure C++ vtable is restored");
421 assert(on_stack(), "should always be set for shared constant pools");
422 assert(is_shared(), "should always be set for shared constant pools");
423 if (is_for_method_handle_intrinsic()) {
424 // See the same check in remove_unshareable_info() below.
425 assert(cache() == nullptr, "must not have cpCache");
426 return;
427 }
428 assert(_cache != nullptr, "constant pool _cache should not be null");
429
430 // Only create the new resolved references array if it hasn't been attempted before
431 if (resolved_references() != nullptr) return;
432
433 if (vmClasses::Object_klass_loaded()) {
434 ClassLoaderData* loader_data = pool_holder()->class_loader_data();
435 #if INCLUDE_CDS_JAVA_HEAP
436 if (ArchiveHeapLoader::is_in_use() &&
437 _cache->archived_references() != nullptr) {
438 oop archived = _cache->archived_references();
439 // Create handle for the archived resolved reference array object
440 HandleMark hm(THREAD);
441 Handle refs_handle(THREAD, archived);
442 set_resolved_references(loader_data->add_handle(refs_handle));
443 _cache->clear_archived_references();
444 } else
445 #endif
446 {
447 // No mapped archived resolved reference array
448 // Recreate the object array and add to ClassLoaderData.
449 int map_length = resolved_reference_length();
450 if (map_length > 0) {
451 objArrayOop stom = oopFactory::new_objArray(vmClasses::Object_klass(), map_length, CHECK);
452 HandleMark hm(THREAD);
453 Handle refs_handle(THREAD, stom); // must handleize.
454 set_resolved_references(loader_data->add_handle(refs_handle));
455 }
456 }
457 }
458
459 if (CDSConfig::is_dumping_final_static_archive() && CDSConfig::is_dumping_heap() && resolved_references() != nullptr) {
460 objArrayOop scratch_references = oopFactory::new_objArray(vmClasses::Object_klass(), resolved_references()->length(), CHECK);
461 HeapShared::add_scratch_resolved_references(this, scratch_references);
462 }
463 }
464
465 void ConstantPool::remove_unshareable_info() {
466 // Shared ConstantPools are in the RO region, so the _flags cannot be modified.
467 // The _on_stack flag is used to prevent ConstantPools from deallocation during
468 // class redefinition. Since shared ConstantPools cannot be deallocated anyway,
469 // we always set _on_stack to true to avoid having to change _flags during runtime.
470 _flags |= (_on_stack | _is_shared);
471
472 if (is_for_method_handle_intrinsic()) {
473 // This CP was created by Method::make_method_handle_intrinsic() and has nothing
474 // that need to be removed/restored. It has no cpCache since the intrinsic methods
475 // don't have any bytecodes.
476 assert(cache() == nullptr, "must not have cpCache");
477 return;
478 }
479
480 bool update_resolved_reference = true;
481 if (CDSConfig::is_dumping_final_static_archive()) {
482 ConstantPool* src_cp = ArchiveBuilder::current()->get_source_addr(this);
483 InstanceKlass* src_holder = src_cp->pool_holder();
484 if (src_holder->is_shared_unregistered_class()) {
485 // Unregistered classes are not loaded in the AOT assembly phase. The resolved reference length
486 // is already saved during the training run.
487 precond(!src_holder->is_loaded());
488 precond(resolved_reference_length() >= 0);
489 precond(resolved_references() == nullptr);
490 update_resolved_reference = false;
491 }
492 }
493
494 // resolved_references(): remember its length. If it cannot be restored
495 // from the archived heap objects at run time, we need to dynamically allocate it.
496 if (update_resolved_reference && cache() != nullptr) {
497 set_resolved_reference_length(
498 resolved_references() != nullptr ? resolved_references()->length() : 0);
499 set_resolved_references(OopHandle());
500 }
501 remove_unshareable_entries();
502 }
503
504 static const char* get_type(Klass* k) {
505 const char* type;
506 Klass* src_k;
507 if (ArchiveBuilder::is_active() && ArchiveBuilder::current()->is_in_buffer_space(k)) {
508 src_k = ArchiveBuilder::current()->get_source_addr(k);
509 } else {
510 src_k = k;
511 }
512
513 if (src_k->is_objArray_klass()) {
514 src_k = ObjArrayKlass::cast(src_k)->bottom_klass();
515 assert(!src_k->is_objArray_klass(), "sanity");
516 }
517
518 if (src_k->is_typeArray_klass()) {
519 type = "prim";
520 } else {
521 InstanceKlass* src_ik = InstanceKlass::cast(src_k);
522 oop loader = src_ik->class_loader();
523 if (loader == nullptr) {
524 type = "boot";
525 } else if (loader == SystemDictionary::java_platform_loader()) {
526 type = "plat";
527 } else if (loader == SystemDictionary::java_system_loader()) {
528 type = "app";
529 } else {
530 type = "unreg";
531 }
532 }
533
534 return type;
535 }
536
537 void ConstantPool::remove_unshareable_entries() {
538 ResourceMark rm;
539 log_info(cds, resolve)("Archiving CP entries for %s", pool_holder()->name()->as_C_string());
540 for (int cp_index = 1; cp_index < length(); cp_index++) { // cp_index 0 is unused
541 int cp_tag = tag_at(cp_index).value();
542 switch (cp_tag) {
543 case JVM_CONSTANT_UnresolvedClass:
544 ArchiveBuilder::alloc_stats()->record_klass_cp_entry(false, false);
545 break;
546 case JVM_CONSTANT_UnresolvedClassInError:
547 tag_at_put(cp_index, JVM_CONSTANT_UnresolvedClass);
548 ArchiveBuilder::alloc_stats()->record_klass_cp_entry(false, true);
549 break;
550 case JVM_CONSTANT_MethodHandleInError:
551 tag_at_put(cp_index, JVM_CONSTANT_MethodHandle);
552 break;
553 case JVM_CONSTANT_MethodTypeInError:
554 tag_at_put(cp_index, JVM_CONSTANT_MethodType);
555 break;
556 case JVM_CONSTANT_DynamicInError:
557 tag_at_put(cp_index, JVM_CONSTANT_Dynamic);
558 break;
559 case JVM_CONSTANT_Class:
560 remove_resolved_klass_if_non_deterministic(cp_index);
561 break;
562 default:
563 break;
564 }
565 }
566
567 if (cache() != nullptr) {
568 // cache() is null if this class is not yet linked.
569 cache()->remove_unshareable_info();
570 }
571 }
572
573 void ConstantPool::remove_resolved_klass_if_non_deterministic(int cp_index) {
574 assert(ArchiveBuilder::current()->is_in_buffer_space(this), "must be");
575 assert(tag_at(cp_index).is_klass(), "must be resolved");
576
577 Klass* k = resolved_klass_at(cp_index);
578 bool can_archive;
579
580 if (k == nullptr) {
581 // We'd come here if the referenced class has been excluded via
582 // SystemDictionaryShared::is_excluded_class(). As a result, ArchiveBuilder
583 // has cleared the resolved_klasses()->at(...) pointer to null. Thus, we
584 // need to revert the tag to JVM_CONSTANT_UnresolvedClass.
585 can_archive = false;
586 } else {
587 ConstantPool* src_cp = ArchiveBuilder::current()->get_source_addr(this);
588 can_archive = AOTConstantPoolResolver::is_resolution_deterministic(src_cp, cp_index);
589 }
590
591 if (!can_archive) {
592 int resolved_klass_index = klass_slot_at(cp_index).resolved_klass_index();
593 // This might be at a safepoint but do this in the right order.
594 tag_at_put(cp_index, JVM_CONSTANT_UnresolvedClass);
595 resolved_klasses()->at_put(resolved_klass_index, nullptr);
596 }
597
598 LogStreamHandle(Trace, cds, resolve) log;
599 if (log.is_enabled()) {
600 ResourceMark rm;
601 log.print("%s klass CP entry [%3d]: %s %s",
602 (can_archive ? "archived" : "reverted"),
603 cp_index, pool_holder()->name()->as_C_string(), get_type(pool_holder()));
604 if (can_archive) {
605 log.print(" => %s %s%s", k->name()->as_C_string(), get_type(k),
606 (!k->is_instance_klass() || pool_holder()->is_subtype_of(k)) ? "" : " (not supertype)");
607 } else {
608 Symbol* name = klass_name_at(cp_index);
609 log.print(" => %s", name->as_C_string());
610 }
611 }
612
613 ArchiveBuilder::alloc_stats()->record_klass_cp_entry(can_archive, /*reverted=*/!can_archive);
614 }
615 #endif // INCLUDE_CDS
616
617 int ConstantPool::cp_to_object_index(int cp_index) {
618 // this is harder don't do this so much.
619 int i = reference_map()->find(checked_cast<u2>(cp_index));
620 // We might not find the index for jsr292 call.
621 return (i < 0) ? _no_index_sentinel : i;
622 }
623
624 void ConstantPool::string_at_put(int obj_index, oop str) {
625 oop result = set_resolved_reference_at(obj_index, str);
626 assert(result == nullptr || result == str, "Only set once or to the same string.");
627 }
628
629 void ConstantPool::trace_class_resolution(const constantPoolHandle& this_cp, Klass* k) {
630 ResourceMark rm;
631 int line_number = -1;
632 const char * source_file = nullptr;
633 if (JavaThread::current()->has_last_Java_frame()) {
634 // try to identify the method which called this function.
635 vframeStream vfst(JavaThread::current());
636 if (!vfst.at_end()) {
637 line_number = vfst.method()->line_number_from_bci(vfst.bci());
638 Symbol* s = vfst.method()->method_holder()->source_file_name();
639 if (s != nullptr) {
640 source_file = s->as_C_string();
641 }
642 }
643 }
644 if (k != this_cp->pool_holder()) {
645 // only print something if the classes are different
646 if (source_file != nullptr) {
647 log_debug(class, resolve)("%s %s %s:%d",
648 this_cp->pool_holder()->external_name(),
649 k->external_name(), source_file, line_number);
650 } else {
651 log_debug(class, resolve)("%s %s",
652 this_cp->pool_holder()->external_name(),
653 k->external_name());
654 }
655 }
656 }
657
658 void check_is_inline_type(Klass* k, TRAPS) {
659 if (!k->is_inline_klass()) {
660 THROW(vmSymbols::java_lang_IncompatibleClassChangeError());
661 }
662 }
663
664 Klass* ConstantPool::klass_at_impl(const constantPoolHandle& this_cp, int cp_index,
665 TRAPS) {
666 JavaThread* javaThread = THREAD;
667
668 // A resolved constantPool entry will contain a Klass*, otherwise a Symbol*.
669 // It is not safe to rely on the tag bit's here, since we don't have a lock, and
670 // the entry and tag is not updated atomically.
671 CPKlassSlot kslot = this_cp->klass_slot_at(cp_index);
672 int resolved_klass_index = kslot.resolved_klass_index();
673 int name_index = kslot.name_index();
674 assert(this_cp->tag_at(name_index).is_symbol(), "sanity");
675
676 // The tag must be JVM_CONSTANT_Class in order to read the correct value from
677 // the unresolved_klasses() array.
678 if (this_cp->tag_at(cp_index).is_klass()) {
679 Klass* klass = this_cp->resolved_klasses()->at(resolved_klass_index);
680 assert(klass != nullptr, "must be resolved");
681 return klass;
682 }
683
684 // This tag doesn't change back to unresolved class unless at a safepoint.
685 if (this_cp->tag_at(cp_index).is_unresolved_klass_in_error()) {
686 // The original attempt to resolve this constant pool entry failed so find the
687 // class of the original error and throw another error of the same class
688 // (JVMS 5.4.3).
689 // If there is a detail message, pass that detail message to the error.
690 // The JVMS does not strictly require us to duplicate the same detail message,
691 // or any internal exception fields such as cause or stacktrace. But since the
692 // detail message is often a class name or other literal string, we will repeat it
693 // if we can find it in the symbol table.
694 throw_resolution_error(this_cp, cp_index, CHECK_NULL);
695 ShouldNotReachHere();
696 }
697
698 HandleMark hm(THREAD);
699 Handle mirror_handle;
700 Symbol* name = this_cp->symbol_at(name_index);
701 bool inline_type_signature = false;
702 Handle loader (THREAD, this_cp->pool_holder()->class_loader());
703
704 Klass* k;
705 {
706 // Turn off the single stepping while doing class resolution
707 JvmtiHideSingleStepping jhss(javaThread);
708 k = SystemDictionary::resolve_or_fail(name, loader, true, THREAD);
709 } // JvmtiHideSingleStepping jhss(javaThread);
710 if (inline_type_signature) {
711 name->decrement_refcount();
712 }
713
714 if (!HAS_PENDING_EXCEPTION) {
715 // preserve the resolved klass from unloading
716 mirror_handle = Handle(THREAD, k->java_mirror());
717 // Do access check for klasses
718 verify_constant_pool_resolve(this_cp, k, THREAD);
719 }
720
721 if (!HAS_PENDING_EXCEPTION && inline_type_signature) {
722 check_is_inline_type(k, THREAD);
723 }
724
725 if (!HAS_PENDING_EXCEPTION) {
726 Klass* bottom_klass = nullptr;
727 if (k->is_objArray_klass()) {
728 bottom_klass = ObjArrayKlass::cast(k)->bottom_klass();
729 assert(bottom_klass != nullptr, "Should be set");
730 assert(bottom_klass->is_instance_klass() || bottom_klass->is_typeArray_klass(), "Sanity check");
731 } else if (k->is_flatArray_klass()) {
732 bottom_klass = FlatArrayKlass::cast(k)->element_klass();
733 assert(bottom_klass != nullptr, "Should be set");
734 }
735 }
736
737 // Failed to resolve class. We must record the errors so that subsequent attempts
738 // to resolve this constant pool entry fail with the same error (JVMS 5.4.3).
739 if (HAS_PENDING_EXCEPTION) {
740 save_and_throw_exception(this_cp, cp_index, constantTag(JVM_CONSTANT_UnresolvedClass), CHECK_NULL);
741 // If CHECK_NULL above doesn't return the exception, that means that
742 // some other thread has beaten us and has resolved the class.
743 // To preserve old behavior, we return the resolved class.
744 Klass* klass = this_cp->resolved_klasses()->at(resolved_klass_index);
745 assert(klass != nullptr, "must be resolved if exception was cleared");
746 return klass;
747 }
748
749 // logging for class+resolve.
750 if (log_is_enabled(Debug, class, resolve)){
751 trace_class_resolution(this_cp, k);
752 }
753
754 // The interpreter assumes when the tag is stored, the klass is resolved
755 // and the Klass* stored in _resolved_klasses is non-null, so we need
756 // hardware store ordering here.
757 // We also need to CAS to not overwrite an error from a racing thread.
758 Klass** adr = this_cp->resolved_klasses()->adr_at(resolved_klass_index);
759 Atomic::release_store(adr, k);
760
761 jbyte old_tag = Atomic::cmpxchg((jbyte*)this_cp->tag_addr_at(cp_index),
762 (jbyte)JVM_CONSTANT_UnresolvedClass,
763 (jbyte)JVM_CONSTANT_Class);
764
765 // We need to recheck exceptions from racing thread and return the same.
766 if (old_tag == JVM_CONSTANT_UnresolvedClassInError) {
767 // Remove klass.
768 Atomic::store(adr, (Klass*)nullptr);
769 throw_resolution_error(this_cp, cp_index, CHECK_NULL);
770 }
771
772 return k;
773 }
774
775
776 // Does not update ConstantPool* - to avoid any exception throwing. Used
777 // by compiler and exception handling. Also used to avoid classloads for
778 // instanceof operations. Returns null if the class has not been loaded or
779 // if the verification of constant pool failed
780 Klass* ConstantPool::klass_at_if_loaded(const constantPoolHandle& this_cp, int which) {
781 CPKlassSlot kslot = this_cp->klass_slot_at(which);
782 int resolved_klass_index = kslot.resolved_klass_index();
783 int name_index = kslot.name_index();
784 assert(this_cp->tag_at(name_index).is_symbol(), "sanity");
785
786 if (this_cp->tag_at(which).is_klass()) {
787 Klass* k = this_cp->resolved_klasses()->at(resolved_klass_index);
788 assert(k != nullptr, "must be resolved");
789 return k;
790 } else if (this_cp->tag_at(which).is_unresolved_klass_in_error()) {
791 return nullptr;
792 } else {
793 Thread* current = Thread::current();
794 HandleMark hm(current);
795 Symbol* name = this_cp->symbol_at(name_index);
796 oop loader = this_cp->pool_holder()->class_loader();
797 Handle h_loader (current, loader);
798 Klass* k = SystemDictionary::find_instance_klass(current, name, h_loader);
799
800 // Avoid constant pool verification at a safepoint, as it takes the Module_lock.
801 if (k != nullptr && current->is_Java_thread()) {
802 // Make sure that resolving is legal
803 JavaThread* THREAD = JavaThread::cast(current); // For exception macros.
804 ExceptionMark em(THREAD);
805 // return null if verification fails
806 verify_constant_pool_resolve(this_cp, k, THREAD);
807 if (HAS_PENDING_EXCEPTION) {
808 CLEAR_PENDING_EXCEPTION;
809 return nullptr;
810 }
811 return k;
812 } else {
813 return k;
814 }
815 }
816 }
817
818 Method* ConstantPool::method_at_if_loaded(const constantPoolHandle& cpool,
819 int which) {
820 if (cpool->cache() == nullptr) return nullptr; // nothing to load yet
821 if (!(which >= 0 && which < cpool->resolved_method_entries_length())) {
822 // FIXME: should be an assert
823 log_debug(class, resolve)("bad operand %d in:", which); cpool->print();
824 return nullptr;
825 }
826 return cpool->cache()->method_if_resolved(which);
827 }
828
829
830 bool ConstantPool::has_appendix_at_if_loaded(const constantPoolHandle& cpool, int which, Bytecodes::Code code) {
831 if (cpool->cache() == nullptr) return false; // nothing to load yet
832 if (code == Bytecodes::_invokedynamic) {
833 return cpool->resolved_indy_entry_at(which)->has_appendix();
834 } else {
835 return cpool->resolved_method_entry_at(which)->has_appendix();
836 }
837 }
838
839 oop ConstantPool::appendix_at_if_loaded(const constantPoolHandle& cpool, int which, Bytecodes::Code code) {
840 if (cpool->cache() == nullptr) return nullptr; // nothing to load yet
841 if (code == Bytecodes::_invokedynamic) {
842 return cpool->resolved_reference_from_indy(which);
843 } else {
844 return cpool->cache()->appendix_if_resolved(which);
845 }
846 }
847
848
849 bool ConstantPool::has_local_signature_at_if_loaded(const constantPoolHandle& cpool, int which, Bytecodes::Code code) {
850 if (cpool->cache() == nullptr) return false; // nothing to load yet
851 if (code == Bytecodes::_invokedynamic) {
852 return cpool->resolved_indy_entry_at(which)->has_local_signature();
853 } else {
854 return cpool->resolved_method_entry_at(which)->has_local_signature();
855 }
856 }
857
858 // Translate index, which could be CPCache index or Indy index, to a constant pool index
859 int ConstantPool::to_cp_index(int index, Bytecodes::Code code) {
860 assert(cache() != nullptr, "'index' is a rewritten index so this class must have been rewritten");
861 switch(code) {
862 case Bytecodes::_invokedynamic:
863 return invokedynamic_bootstrap_ref_index_at(index);
864 case Bytecodes::_getfield:
865 case Bytecodes::_getstatic:
866 case Bytecodes::_putfield:
867 case Bytecodes::_putstatic:
868 return resolved_field_entry_at(index)->constant_pool_index();
869 case Bytecodes::_invokeinterface:
870 case Bytecodes::_invokehandle:
871 case Bytecodes::_invokespecial:
872 case Bytecodes::_invokestatic:
873 case Bytecodes::_invokevirtual:
874 case Bytecodes::_fast_invokevfinal: // Bytecode interpreter uses this
875 return resolved_method_entry_at(index)->constant_pool_index();
876 default:
877 fatal("Unexpected bytecode: %s", Bytecodes::name(code));
878 }
879 }
880
881 bool ConstantPool::is_resolved(int index, Bytecodes::Code code) {
882 assert(cache() != nullptr, "'index' is a rewritten index so this class must have been rewritten");
883 switch(code) {
884 case Bytecodes::_invokedynamic:
885 return resolved_indy_entry_at(index)->is_resolved();
886
887 case Bytecodes::_getfield:
888 case Bytecodes::_getstatic:
889 case Bytecodes::_putfield:
890 case Bytecodes::_putstatic:
891 return resolved_field_entry_at(index)->is_resolved(code);
892
893 case Bytecodes::_invokeinterface:
894 case Bytecodes::_invokehandle:
895 case Bytecodes::_invokespecial:
896 case Bytecodes::_invokestatic:
897 case Bytecodes::_invokevirtual:
898 case Bytecodes::_fast_invokevfinal: // Bytecode interpreter uses this
899 return resolved_method_entry_at(index)->is_resolved(code);
900
901 default:
902 fatal("Unexpected bytecode: %s", Bytecodes::name(code));
903 }
904 }
905
906 u2 ConstantPool::uncached_name_and_type_ref_index_at(int cp_index) {
907 if (tag_at(cp_index).has_bootstrap()) {
908 u2 pool_index = bootstrap_name_and_type_ref_index_at(cp_index);
909 assert(tag_at(pool_index).is_name_and_type(), "");
910 return pool_index;
911 }
912 assert(tag_at(cp_index).is_field_or_method(), "Corrupted constant pool");
913 assert(!tag_at(cp_index).has_bootstrap(), "Must be handled above");
914 jint ref_index = *int_at_addr(cp_index);
915 return extract_high_short_from_int(ref_index);
916 }
917
918 u2 ConstantPool::name_and_type_ref_index_at(int index, Bytecodes::Code code) {
919 return uncached_name_and_type_ref_index_at(to_cp_index(index, code));
920 }
921
922 constantTag ConstantPool::tag_ref_at(int which, Bytecodes::Code code) {
923 // which may be either a Constant Pool index or a rewritten index
924 int pool_index = which;
925 assert(cache() != nullptr, "'index' is a rewritten index so this class must have been rewritten");
926 pool_index = to_cp_index(which, code);
927 return tag_at(pool_index);
928 }
929
930 u2 ConstantPool::uncached_klass_ref_index_at(int cp_index) {
931 assert(tag_at(cp_index).is_field_or_method(), "Corrupted constant pool");
932 jint ref_index = *int_at_addr(cp_index);
933 return extract_low_short_from_int(ref_index);
934 }
935
936 u2 ConstantPool::klass_ref_index_at(int index, Bytecodes::Code code) {
937 assert(code != Bytecodes::_invokedynamic,
938 "an invokedynamic instruction does not have a klass");
939 return uncached_klass_ref_index_at(to_cp_index(index, code));
940 }
941
942 void ConstantPool::verify_constant_pool_resolve(const constantPoolHandle& this_cp, Klass* k, TRAPS) {
943 if (!(k->is_instance_klass() || k->is_objArray_klass())) {
944 return; // short cut, typeArray klass is always accessible
945 }
946 Klass* holder = this_cp->pool_holder();
947 LinkResolver::check_klass_accessibility(holder, k, CHECK);
948 }
949
950
951 u2 ConstantPool::name_ref_index_at(int cp_index) {
952 jint ref_index = name_and_type_at(cp_index);
953 return extract_low_short_from_int(ref_index);
954 }
955
956
957 u2 ConstantPool::signature_ref_index_at(int cp_index) {
958 jint ref_index = name_and_type_at(cp_index);
959 return extract_high_short_from_int(ref_index);
960 }
961
962
963 Klass* ConstantPool::klass_ref_at(int which, Bytecodes::Code code, TRAPS) {
964 return klass_at(klass_ref_index_at(which, code), THREAD);
965 }
966
967 Symbol* ConstantPool::klass_name_at(int cp_index) const {
968 return symbol_at(klass_slot_at(cp_index).name_index());
969 }
970
971 Symbol* ConstantPool::klass_ref_at_noresolve(int which, Bytecodes::Code code) {
972 jint ref_index = klass_ref_index_at(which, code);
973 return klass_at_noresolve(ref_index);
974 }
975
976 Symbol* ConstantPool::uncached_klass_ref_at_noresolve(int cp_index) {
977 jint ref_index = uncached_klass_ref_index_at(cp_index);
978 return klass_at_noresolve(ref_index);
979 }
980
981 char* ConstantPool::string_at_noresolve(int cp_index) {
982 return unresolved_string_at(cp_index)->as_C_string();
983 }
984
985 BasicType ConstantPool::basic_type_for_signature_at(int cp_index) const {
986 return Signature::basic_type(symbol_at(cp_index));
987 }
988
989
990 void ConstantPool::resolve_string_constants_impl(const constantPoolHandle& this_cp, TRAPS) {
991 for (int index = 1; index < this_cp->length(); index++) { // Index 0 is unused
992 if (this_cp->tag_at(index).is_string()) {
993 this_cp->string_at(index, CHECK);
994 }
995 }
996 }
997
998 static const char* exception_message(const constantPoolHandle& this_cp, int which, constantTag tag, oop pending_exception) {
999 // Note: caller needs ResourceMark
1000
1001 // Dig out the detailed message to reuse if possible
1002 const char* msg = java_lang_Throwable::message_as_utf8(pending_exception);
1003 if (msg != nullptr) {
1004 return msg;
1005 }
1006
1007 Symbol* message = nullptr;
1008 // Return specific message for the tag
1009 switch (tag.value()) {
1010 case JVM_CONSTANT_UnresolvedClass:
1011 // return the class name in the error message
1012 message = this_cp->klass_name_at(which);
1013 break;
1014 case JVM_CONSTANT_MethodHandle:
1015 // return the method handle name in the error message
1016 message = this_cp->method_handle_name_ref_at(which);
1017 break;
1018 case JVM_CONSTANT_MethodType:
1019 // return the method type signature in the error message
1020 message = this_cp->method_type_signature_at(which);
1021 break;
1022 case JVM_CONSTANT_Dynamic:
1023 // return the name of the condy in the error message
1024 message = this_cp->uncached_name_ref_at(which);
1025 break;
1026 default:
1027 ShouldNotReachHere();
1028 }
1029
1030 return message != nullptr ? message->as_C_string() : nullptr;
1031 }
1032
1033 static void add_resolution_error(JavaThread* current, const constantPoolHandle& this_cp, int which,
1034 constantTag tag, oop pending_exception) {
1035
1036 ResourceMark rm(current);
1037 Symbol* error = pending_exception->klass()->name();
1038 oop cause = java_lang_Throwable::cause(pending_exception);
1039
1040 // Also dig out the exception cause, if present.
1041 Symbol* cause_sym = nullptr;
1042 const char* cause_msg = nullptr;
1043 if (cause != nullptr && cause != pending_exception) {
1044 cause_sym = cause->klass()->name();
1045 cause_msg = java_lang_Throwable::message_as_utf8(cause);
1046 }
1047
1048 const char* message = exception_message(this_cp, which, tag, pending_exception);
1049 SystemDictionary::add_resolution_error(this_cp, which, error, message, cause_sym, cause_msg);
1050 }
1051
1052
1053 void ConstantPool::throw_resolution_error(const constantPoolHandle& this_cp, int which, TRAPS) {
1054 ResourceMark rm(THREAD);
1055 const char* message = nullptr;
1056 Symbol* cause = nullptr;
1057 const char* cause_msg = nullptr;
1058 Symbol* error = SystemDictionary::find_resolution_error(this_cp, which, &message, &cause, &cause_msg);
1059 assert(error != nullptr, "checking");
1060
1061 CLEAR_PENDING_EXCEPTION;
1062 if (message != nullptr) {
1063 if (cause != nullptr) {
1064 Handle h_cause = Exceptions::new_exception(THREAD, cause, cause_msg);
1065 THROW_MSG_CAUSE(error, message, h_cause);
1066 } else {
1067 THROW_MSG(error, message);
1068 }
1069 } else {
1070 if (cause != nullptr) {
1071 Handle h_cause = Exceptions::new_exception(THREAD, cause, cause_msg);
1072 THROW_CAUSE(error, h_cause);
1073 } else {
1074 THROW(error);
1075 }
1076 }
1077 }
1078
1079 // If resolution for Class, Dynamic constant, MethodHandle or MethodType fails, save the
1080 // exception in the resolution error table, so that the same exception is thrown again.
1081 void ConstantPool::save_and_throw_exception(const constantPoolHandle& this_cp, int cp_index,
1082 constantTag tag, TRAPS) {
1083
1084 int error_tag = tag.error_value();
1085
1086 if (!PENDING_EXCEPTION->
1087 is_a(vmClasses::LinkageError_klass())) {
1088 // Just throw the exception and don't prevent these classes from
1089 // being loaded due to virtual machine errors like StackOverflow
1090 // and OutOfMemoryError, etc, or if the thread was hit by stop()
1091 // Needs clarification to section 5.4.3 of the VM spec (see 6308271)
1092 } else if (this_cp->tag_at(cp_index).value() != error_tag) {
1093 add_resolution_error(THREAD, this_cp, cp_index, tag, PENDING_EXCEPTION);
1094 // CAS in the tag. If a thread beat us to registering this error that's fine.
1095 // If another thread resolved the reference, this is a race condition. This
1096 // thread may have had a security manager or something temporary.
1097 // This doesn't deterministically get an error. So why do we save this?
1098 // We save this because jvmti can add classes to the bootclass path after
1099 // this error, so it needs to get the same error if the error is first.
1100 jbyte old_tag = Atomic::cmpxchg((jbyte*)this_cp->tag_addr_at(cp_index),
1101 (jbyte)tag.value(),
1102 (jbyte)error_tag);
1103 if (old_tag != error_tag && old_tag != tag.value()) {
1104 // MethodHandles and MethodType doesn't change to resolved version.
1105 assert(this_cp->tag_at(cp_index).is_klass(), "Wrong tag value");
1106 // Forget the exception and use the resolved class.
1107 CLEAR_PENDING_EXCEPTION;
1108 }
1109 } else {
1110 // some other thread put this in error state
1111 throw_resolution_error(this_cp, cp_index, CHECK);
1112 }
1113 }
1114
1115 constantTag ConstantPool::constant_tag_at(int cp_index) {
1116 constantTag tag = tag_at(cp_index);
1117 if (tag.is_dynamic_constant()) {
1118 BasicType bt = basic_type_for_constant_at(cp_index);
1119 return constantTag(constantTag::type2tag(bt));
1120 }
1121 return tag;
1122 }
1123
1124 BasicType ConstantPool::basic_type_for_constant_at(int cp_index) {
1125 constantTag tag = tag_at(cp_index);
1126 if (tag.is_dynamic_constant() ||
1127 tag.is_dynamic_constant_in_error()) {
1128 // have to look at the signature for this one
1129 Symbol* constant_type = uncached_signature_ref_at(cp_index);
1130 return Signature::basic_type(constant_type);
1131 }
1132 return tag.basic_type();
1133 }
1134
1135 // Called to resolve constants in the constant pool and return an oop.
1136 // Some constant pool entries cache their resolved oop. This is also
1137 // called to create oops from constants to use in arguments for invokedynamic
1138 oop ConstantPool::resolve_constant_at_impl(const constantPoolHandle& this_cp,
1139 int cp_index, int cache_index,
1140 bool* status_return, TRAPS) {
1141 oop result_oop = nullptr;
1142
1143 if (cache_index == _possible_index_sentinel) {
1144 // It is possible that this constant is one which is cached in the objects.
1145 // We'll do a linear search. This should be OK because this usage is rare.
1146 // FIXME: If bootstrap specifiers stress this code, consider putting in
1147 // a reverse index. Binary search over a short array should do it.
1148 assert(cp_index > 0, "valid constant pool index");
1149 cache_index = this_cp->cp_to_object_index(cp_index);
1150 }
1151 assert(cache_index == _no_index_sentinel || cache_index >= 0, "");
1152 assert(cp_index == _no_index_sentinel || cp_index >= 0, "");
1153
1154 if (cache_index >= 0) {
1155 result_oop = this_cp->resolved_reference_at(cache_index);
1156 if (result_oop != nullptr) {
1157 if (result_oop == Universe::the_null_sentinel()) {
1158 DEBUG_ONLY(int temp_index = (cp_index >= 0 ? cp_index : this_cp->object_to_cp_index(cache_index)));
1159 assert(this_cp->tag_at(temp_index).is_dynamic_constant(), "only condy uses the null sentinel");
1160 result_oop = nullptr;
1161 }
1162 if (status_return != nullptr) (*status_return) = true;
1163 return result_oop;
1164 // That was easy...
1165 }
1166 cp_index = this_cp->object_to_cp_index(cache_index);
1167 }
1168
1169 jvalue prim_value; // temp used only in a few cases below
1170
1171 constantTag tag = this_cp->tag_at(cp_index);
1172
1173 if (status_return != nullptr) {
1174 // don't trigger resolution if the constant might need it
1175 switch (tag.value()) {
1176 case JVM_CONSTANT_Class:
1177 assert(this_cp->resolved_klass_at(cp_index) != nullptr, "must be resolved");
1178 break;
1179 case JVM_CONSTANT_String:
1180 case JVM_CONSTANT_Integer:
1181 case JVM_CONSTANT_Float:
1182 case JVM_CONSTANT_Long:
1183 case JVM_CONSTANT_Double:
1184 // these guys trigger OOM at worst
1185 break;
1186 default:
1187 (*status_return) = false;
1188 return nullptr;
1189 }
1190 // from now on there is either success or an OOME
1191 (*status_return) = true;
1192 }
1193
1194 switch (tag.value()) {
1195
1196 case JVM_CONSTANT_UnresolvedClass:
1197 case JVM_CONSTANT_Class:
1198 {
1199 assert(cache_index == _no_index_sentinel, "should not have been set");
1200 Klass* resolved = klass_at_impl(this_cp, cp_index, CHECK_NULL);
1201 // ldc wants the java mirror.
1202 result_oop = resolved->java_mirror();
1203 break;
1204 }
1205
1206 case JVM_CONSTANT_Dynamic:
1207 { PerfTraceTimedEvent timer(ClassLoader::perf_resolve_invokedynamic_time(),
1208 ClassLoader::perf_resolve_invokedynamic_count());
1209
1210 // Resolve the Dynamically-Computed constant to invoke the BSM in order to obtain the resulting oop.
1211 BootstrapInfo bootstrap_specifier(this_cp, cp_index);
1212
1213 // The initial step in resolving an unresolved symbolic reference to a
1214 // dynamically-computed constant is to resolve the symbolic reference to a
1215 // method handle which will be the bootstrap method for the dynamically-computed
1216 // constant. If resolution of the java.lang.invoke.MethodHandle for the bootstrap
1217 // method fails, then a MethodHandleInError is stored at the corresponding
1218 // bootstrap method's CP index for the CONSTANT_MethodHandle_info. No need to
1219 // set a DynamicConstantInError here since any subsequent use of this
1220 // bootstrap method will encounter the resolution of MethodHandleInError.
1221 // Both the first, (resolution of the BSM and its static arguments), and the second tasks,
1222 // (invocation of the BSM), of JVMS Section 5.4.3.6 occur within invoke_bootstrap_method()
1223 // for the bootstrap_specifier created above.
1224 SystemDictionary::invoke_bootstrap_method(bootstrap_specifier, THREAD);
1225 Exceptions::wrap_dynamic_exception(/* is_indy */ false, THREAD);
1226 if (HAS_PENDING_EXCEPTION) {
1227 // Resolution failure of the dynamically-computed constant, save_and_throw_exception
1228 // will check for a LinkageError and store a DynamicConstantInError.
1229 save_and_throw_exception(this_cp, cp_index, tag, CHECK_NULL);
1230 }
1231 result_oop = bootstrap_specifier.resolved_value()();
1232 BasicType type = Signature::basic_type(bootstrap_specifier.signature());
1233 if (!is_reference_type(type)) {
1234 // Make sure the primitive value is properly boxed.
1235 // This is a JDK responsibility.
1236 const char* fail = nullptr;
1237 if (result_oop == nullptr) {
1238 fail = "null result instead of box";
1239 } else if (!is_java_primitive(type)) {
1240 // FIXME: support value types via unboxing
1241 fail = "can only handle references and primitives";
1242 } else if (!java_lang_boxing_object::is_instance(result_oop, type)) {
1243 fail = "primitive is not properly boxed";
1244 }
1245 if (fail != nullptr) {
1246 // Since this exception is not a LinkageError, throw exception
1247 // but do not save a DynamicInError resolution result.
1248 // See section 5.4.3 of the VM spec.
1249 THROW_MSG_NULL(vmSymbols::java_lang_InternalError(), fail);
1250 }
1251 }
1252
1253 LogTarget(Debug, methodhandles, condy) lt_condy;
1254 if (lt_condy.is_enabled()) {
1255 LogStream ls(lt_condy);
1256 bootstrap_specifier.print_msg_on(&ls, "resolve_constant_at_impl");
1257 }
1258 break;
1259 }
1260
1261 case JVM_CONSTANT_String:
1262 assert(cache_index != _no_index_sentinel, "should have been set");
1263 result_oop = string_at_impl(this_cp, cp_index, cache_index, CHECK_NULL);
1264 break;
1265
1266 case JVM_CONSTANT_MethodHandle:
1267 { PerfTraceTimedEvent timer(ClassLoader::perf_resolve_method_handle_time(),
1268 ClassLoader::perf_resolve_method_handle_count());
1269
1270 int ref_kind = this_cp->method_handle_ref_kind_at(cp_index);
1271 int callee_index = this_cp->method_handle_klass_index_at(cp_index);
1272 Symbol* name = this_cp->method_handle_name_ref_at(cp_index);
1273 Symbol* signature = this_cp->method_handle_signature_ref_at(cp_index);
1274 constantTag m_tag = this_cp->tag_at(this_cp->method_handle_index_at(cp_index));
1275 { ResourceMark rm(THREAD);
1276 log_debug(class, resolve)("resolve JVM_CONSTANT_MethodHandle:%d [%d/%d/%d] %s.%s",
1277 ref_kind, cp_index, this_cp->method_handle_index_at(cp_index),
1278 callee_index, name->as_C_string(), signature->as_C_string());
1279 }
1280
1281 Klass* callee = klass_at_impl(this_cp, callee_index, THREAD);
1282 if (HAS_PENDING_EXCEPTION) {
1283 save_and_throw_exception(this_cp, cp_index, tag, CHECK_NULL);
1284 }
1285
1286 // Check constant pool method consistency
1287 if ((callee->is_interface() && m_tag.is_method()) ||
1288 (!callee->is_interface() && m_tag.is_interface_method())) {
1289 ResourceMark rm(THREAD);
1290 stringStream ss;
1291 ss.print("Inconsistent constant pool data in classfile for class %s. "
1292 "Method '", callee->name()->as_C_string());
1293 signature->print_as_signature_external_return_type(&ss);
1294 ss.print(" %s(", name->as_C_string());
1295 signature->print_as_signature_external_parameters(&ss);
1296 ss.print(")' at index %d is %s and should be %s",
1297 cp_index,
1298 callee->is_interface() ? "CONSTANT_MethodRef" : "CONSTANT_InterfaceMethodRef",
1299 callee->is_interface() ? "CONSTANT_InterfaceMethodRef" : "CONSTANT_MethodRef");
1300 // Names are all known to be < 64k so we know this formatted message is not excessively large.
1301 Exceptions::fthrow(THREAD_AND_LOCATION, vmSymbols::java_lang_IncompatibleClassChangeError(), "%s", ss.as_string());
1302 save_and_throw_exception(this_cp, cp_index, tag, CHECK_NULL);
1303 }
1304
1305 Klass* klass = this_cp->pool_holder();
1306 HandleMark hm(THREAD);
1307 Handle value = SystemDictionary::link_method_handle_constant(klass, ref_kind,
1308 callee, name, signature,
1309 THREAD);
1310 if (HAS_PENDING_EXCEPTION) {
1311 save_and_throw_exception(this_cp, cp_index, tag, CHECK_NULL);
1312 }
1313 result_oop = value();
1314 break;
1315 }
1316
1317 case JVM_CONSTANT_MethodType:
1318 { PerfTraceTimedEvent timer(ClassLoader::perf_resolve_method_type_time(),
1319 ClassLoader::perf_resolve_method_type_count());
1320
1321 Symbol* signature = this_cp->method_type_signature_at(cp_index);
1322 { ResourceMark rm(THREAD);
1323 log_debug(class, resolve)("resolve JVM_CONSTANT_MethodType [%d/%d] %s",
1324 cp_index, this_cp->method_type_index_at(cp_index),
1325 signature->as_C_string());
1326 }
1327 Klass* klass = this_cp->pool_holder();
1328 HandleMark hm(THREAD);
1329 Handle value = SystemDictionary::find_method_handle_type(signature, klass, THREAD);
1330 result_oop = value();
1331 if (HAS_PENDING_EXCEPTION) {
1332 save_and_throw_exception(this_cp, cp_index, tag, CHECK_NULL);
1333 }
1334 break;
1335 }
1336
1337 case JVM_CONSTANT_Integer:
1338 assert(cache_index == _no_index_sentinel, "should not have been set");
1339 prim_value.i = this_cp->int_at(cp_index);
1340 result_oop = java_lang_boxing_object::create(T_INT, &prim_value, CHECK_NULL);
1341 break;
1342
1343 case JVM_CONSTANT_Float:
1344 assert(cache_index == _no_index_sentinel, "should not have been set");
1345 prim_value.f = this_cp->float_at(cp_index);
1346 result_oop = java_lang_boxing_object::create(T_FLOAT, &prim_value, CHECK_NULL);
1347 break;
1348
1349 case JVM_CONSTANT_Long:
1350 assert(cache_index == _no_index_sentinel, "should not have been set");
1351 prim_value.j = this_cp->long_at(cp_index);
1352 result_oop = java_lang_boxing_object::create(T_LONG, &prim_value, CHECK_NULL);
1353 break;
1354
1355 case JVM_CONSTANT_Double:
1356 assert(cache_index == _no_index_sentinel, "should not have been set");
1357 prim_value.d = this_cp->double_at(cp_index);
1358 result_oop = java_lang_boxing_object::create(T_DOUBLE, &prim_value, CHECK_NULL);
1359 break;
1360
1361 case JVM_CONSTANT_UnresolvedClassInError:
1362 case JVM_CONSTANT_DynamicInError:
1363 case JVM_CONSTANT_MethodHandleInError:
1364 case JVM_CONSTANT_MethodTypeInError:
1365 throw_resolution_error(this_cp, cp_index, CHECK_NULL);
1366 break;
1367
1368 default:
1369 fatal("unexpected constant tag at CP %p[%d/%d] = %d", this_cp(), cp_index, cache_index, tag.value());
1370 break;
1371 }
1372
1373 if (cache_index >= 0) {
1374 // Benign race condition: resolved_references may already be filled in.
1375 // The important thing here is that all threads pick up the same result.
1376 // It doesn't matter which racing thread wins, as long as only one
1377 // result is used by all threads, and all future queries.
1378 oop new_result = (result_oop == nullptr ? Universe::the_null_sentinel() : result_oop);
1379 oop old_result = this_cp->set_resolved_reference_at(cache_index, new_result);
1380 if (old_result == nullptr) {
1381 return result_oop; // was installed
1382 } else {
1383 // Return the winning thread's result. This can be different than
1384 // the result here for MethodHandles.
1385 if (old_result == Universe::the_null_sentinel())
1386 old_result = nullptr;
1387 return old_result;
1388 }
1389 } else {
1390 assert(result_oop != Universe::the_null_sentinel(), "");
1391 return result_oop;
1392 }
1393 }
1394
1395 oop ConstantPool::uncached_string_at(int cp_index, TRAPS) {
1396 Symbol* sym = unresolved_string_at(cp_index);
1397 oop str = StringTable::intern(sym, CHECK_(nullptr));
1398 assert(java_lang_String::is_instance(str), "must be string");
1399 return str;
1400 }
1401
1402 void ConstantPool::copy_bootstrap_arguments_at_impl(const constantPoolHandle& this_cp, int cp_index,
1403 int start_arg, int end_arg,
1404 objArrayHandle info, int pos,
1405 bool must_resolve, Handle if_not_available,
1406 TRAPS) {
1407 int limit = pos + end_arg - start_arg;
1408 // checks: cp_index in range [0..this_cp->length),
1409 // tag at cp_index, start..end in range [0..this_cp->bootstrap_argument_count],
1410 // info array non-null, pos..limit in [0..info.length]
1411 if ((0 >= cp_index || cp_index >= this_cp->length()) ||
1412 !(this_cp->tag_at(cp_index).is_invoke_dynamic() ||
1413 this_cp->tag_at(cp_index).is_dynamic_constant()) ||
1414 (0 > start_arg || start_arg > end_arg) ||
1415 (end_arg > this_cp->bootstrap_argument_count_at(cp_index)) ||
1416 (0 > pos || pos > limit) ||
1417 (info.is_null() || limit > info->length())) {
1418 // An index or something else went wrong; throw an error.
1419 // Since this is an internal API, we don't expect this,
1420 // so we don't bother to craft a nice message.
1421 THROW_MSG(vmSymbols::java_lang_LinkageError(), "bad BSM argument access");
1422 }
1423 // now we can loop safely
1424 int info_i = pos;
1425 for (int i = start_arg; i < end_arg; i++) {
1426 int arg_index = this_cp->bootstrap_argument_index_at(cp_index, i);
1427 oop arg_oop;
1428 if (must_resolve) {
1429 arg_oop = this_cp->resolve_possibly_cached_constant_at(arg_index, CHECK);
1430 } else {
1431 bool found_it = false;
1432 arg_oop = this_cp->find_cached_constant_at(arg_index, found_it, CHECK);
1433 if (!found_it) arg_oop = if_not_available();
1434 }
1435 info->obj_at_put(info_i++, arg_oop);
1436 }
1437 }
1438
1439 oop ConstantPool::string_at_impl(const constantPoolHandle& this_cp, int cp_index, int obj_index, TRAPS) {
1440 // If the string has already been interned, this entry will be non-null
1441 oop str = this_cp->resolved_reference_at(obj_index);
1442 assert(str != Universe::the_null_sentinel(), "");
1443 if (str != nullptr) return str;
1444 Symbol* sym = this_cp->unresolved_string_at(cp_index);
1445 str = StringTable::intern(sym, CHECK_(nullptr));
1446 this_cp->string_at_put(obj_index, str);
1447 assert(java_lang_String::is_instance(str), "must be string");
1448 return str;
1449 }
1450
1451
1452 bool ConstantPool::klass_name_at_matches(const InstanceKlass* k, int cp_index) {
1453 // Names are interned, so we can compare Symbol*s directly
1454 Symbol* cp_name = klass_name_at(cp_index);
1455 return (cp_name == k->name());
1456 }
1457
1458
1459 // Iterate over symbols and decrement ones which are Symbol*s
1460 // This is done during GC.
1461 // Only decrement the UTF8 symbols. Strings point to
1462 // these symbols but didn't increment the reference count.
1463 void ConstantPool::unreference_symbols() {
1464 for (int index = 1; index < length(); index++) { // Index 0 is unused
1465 constantTag tag = tag_at(index);
1466 if (tag.is_symbol()) {
1467 symbol_at(index)->decrement_refcount();
1468 }
1469 }
1470 }
1471
1472
1473 // Compare this constant pool's entry at index1 to the constant pool
1474 // cp2's entry at index2.
1475 bool ConstantPool::compare_entry_to(int index1, const constantPoolHandle& cp2,
1476 int index2) {
1477
1478 // The error tags are equivalent to non-error tags when comparing
1479 jbyte t1 = tag_at(index1).non_error_value();
1480 jbyte t2 = cp2->tag_at(index2).non_error_value();
1481
1482 // Some classes are pre-resolved (like Throwable) which may lead to
1483 // consider it as a different entry. We then revert them back temporarily
1484 // to ensure proper comparison.
1485 if (t1 == JVM_CONSTANT_Class) {
1486 t1 = JVM_CONSTANT_UnresolvedClass;
1487 }
1488 if (t2 == JVM_CONSTANT_Class) {
1489 t2 = JVM_CONSTANT_UnresolvedClass;
1490 }
1491
1492 if (t1 != t2) {
1493 // Not the same entry type so there is nothing else to check. Note
1494 // that this style of checking will consider resolved/unresolved
1495 // class pairs as different.
1496 // From the ConstantPool* API point of view, this is correct
1497 // behavior. See VM_RedefineClasses::merge_constant_pools() to see how this
1498 // plays out in the context of ConstantPool* merging.
1499 return false;
1500 }
1501
1502 switch (t1) {
1503 case JVM_CONSTANT_ClassIndex:
1504 {
1505 int recur1 = klass_index_at(index1);
1506 int recur2 = cp2->klass_index_at(index2);
1507 if (compare_entry_to(recur1, cp2, recur2)) {
1508 return true;
1509 }
1510 } break;
1511
1512 case JVM_CONSTANT_Double:
1513 {
1514 jdouble d1 = double_at(index1);
1515 jdouble d2 = cp2->double_at(index2);
1516 if (d1 == d2) {
1517 return true;
1518 }
1519 } break;
1520
1521 case JVM_CONSTANT_Fieldref:
1522 case JVM_CONSTANT_InterfaceMethodref:
1523 case JVM_CONSTANT_Methodref:
1524 {
1525 int recur1 = uncached_klass_ref_index_at(index1);
1526 int recur2 = cp2->uncached_klass_ref_index_at(index2);
1527 bool match = compare_entry_to(recur1, cp2, recur2);
1528 if (match) {
1529 recur1 = uncached_name_and_type_ref_index_at(index1);
1530 recur2 = cp2->uncached_name_and_type_ref_index_at(index2);
1531 if (compare_entry_to(recur1, cp2, recur2)) {
1532 return true;
1533 }
1534 }
1535 } break;
1536
1537 case JVM_CONSTANT_Float:
1538 {
1539 jfloat f1 = float_at(index1);
1540 jfloat f2 = cp2->float_at(index2);
1541 if (f1 == f2) {
1542 return true;
1543 }
1544 } break;
1545
1546 case JVM_CONSTANT_Integer:
1547 {
1548 jint i1 = int_at(index1);
1549 jint i2 = cp2->int_at(index2);
1550 if (i1 == i2) {
1551 return true;
1552 }
1553 } break;
1554
1555 case JVM_CONSTANT_Long:
1556 {
1557 jlong l1 = long_at(index1);
1558 jlong l2 = cp2->long_at(index2);
1559 if (l1 == l2) {
1560 return true;
1561 }
1562 } break;
1563
1564 case JVM_CONSTANT_NameAndType:
1565 {
1566 int recur1 = name_ref_index_at(index1);
1567 int recur2 = cp2->name_ref_index_at(index2);
1568 if (compare_entry_to(recur1, cp2, recur2)) {
1569 recur1 = signature_ref_index_at(index1);
1570 recur2 = cp2->signature_ref_index_at(index2);
1571 if (compare_entry_to(recur1, cp2, recur2)) {
1572 return true;
1573 }
1574 }
1575 } break;
1576
1577 case JVM_CONSTANT_StringIndex:
1578 {
1579 int recur1 = string_index_at(index1);
1580 int recur2 = cp2->string_index_at(index2);
1581 if (compare_entry_to(recur1, cp2, recur2)) {
1582 return true;
1583 }
1584 } break;
1585
1586 case JVM_CONSTANT_UnresolvedClass:
1587 {
1588 Symbol* k1 = klass_name_at(index1);
1589 Symbol* k2 = cp2->klass_name_at(index2);
1590 if (k1 == k2) {
1591 return true;
1592 }
1593 } break;
1594
1595 case JVM_CONSTANT_MethodType:
1596 {
1597 int k1 = method_type_index_at(index1);
1598 int k2 = cp2->method_type_index_at(index2);
1599 if (compare_entry_to(k1, cp2, k2)) {
1600 return true;
1601 }
1602 } break;
1603
1604 case JVM_CONSTANT_MethodHandle:
1605 {
1606 int k1 = method_handle_ref_kind_at(index1);
1607 int k2 = cp2->method_handle_ref_kind_at(index2);
1608 if (k1 == k2) {
1609 int i1 = method_handle_index_at(index1);
1610 int i2 = cp2->method_handle_index_at(index2);
1611 if (compare_entry_to(i1, cp2, i2)) {
1612 return true;
1613 }
1614 }
1615 } break;
1616
1617 case JVM_CONSTANT_Dynamic:
1618 {
1619 int k1 = bootstrap_name_and_type_ref_index_at(index1);
1620 int k2 = cp2->bootstrap_name_and_type_ref_index_at(index2);
1621 int i1 = bootstrap_methods_attribute_index(index1);
1622 int i2 = cp2->bootstrap_methods_attribute_index(index2);
1623 bool match_entry = compare_entry_to(k1, cp2, k2);
1624 bool match_operand = compare_operand_to(i1, cp2, i2);
1625 return (match_entry && match_operand);
1626 } break;
1627
1628 case JVM_CONSTANT_InvokeDynamic:
1629 {
1630 int k1 = bootstrap_name_and_type_ref_index_at(index1);
1631 int k2 = cp2->bootstrap_name_and_type_ref_index_at(index2);
1632 int i1 = bootstrap_methods_attribute_index(index1);
1633 int i2 = cp2->bootstrap_methods_attribute_index(index2);
1634 bool match_entry = compare_entry_to(k1, cp2, k2);
1635 bool match_operand = compare_operand_to(i1, cp2, i2);
1636 return (match_entry && match_operand);
1637 } break;
1638
1639 case JVM_CONSTANT_String:
1640 {
1641 Symbol* s1 = unresolved_string_at(index1);
1642 Symbol* s2 = cp2->unresolved_string_at(index2);
1643 if (s1 == s2) {
1644 return true;
1645 }
1646 } break;
1647
1648 case JVM_CONSTANT_Utf8:
1649 {
1650 Symbol* s1 = symbol_at(index1);
1651 Symbol* s2 = cp2->symbol_at(index2);
1652 if (s1 == s2) {
1653 return true;
1654 }
1655 } break;
1656
1657 // Invalid is used as the tag for the second constant pool entry
1658 // occupied by JVM_CONSTANT_Double or JVM_CONSTANT_Long. It should
1659 // not be seen by itself.
1660 case JVM_CONSTANT_Invalid: // fall through
1661
1662 default:
1663 ShouldNotReachHere();
1664 break;
1665 }
1666
1667 return false;
1668 } // end compare_entry_to()
1669
1670
1671 // Resize the operands array with delta_len and delta_size.
1672 // Used in RedefineClasses for CP merge.
1673 void ConstantPool::resize_operands(int delta_len, int delta_size, TRAPS) {
1674 int old_len = operand_array_length(operands());
1675 int new_len = old_len + delta_len;
1676 int min_len = (delta_len > 0) ? old_len : new_len;
1677
1678 int old_size = operands()->length();
1679 int new_size = old_size + delta_size;
1680 int min_size = (delta_size > 0) ? old_size : new_size;
1681
1682 ClassLoaderData* loader_data = pool_holder()->class_loader_data();
1683 Array<u2>* new_ops = MetadataFactory::new_array<u2>(loader_data, new_size, CHECK);
1684
1685 // Set index in the resized array for existing elements only
1686 for (int idx = 0; idx < min_len; idx++) {
1687 int offset = operand_offset_at(idx); // offset in original array
1688 operand_offset_at_put(new_ops, idx, offset + 2*delta_len); // offset in resized array
1689 }
1690 // Copy the bootstrap specifiers only
1691 Copy::conjoint_memory_atomic(operands()->adr_at(2*old_len),
1692 new_ops->adr_at(2*new_len),
1693 (min_size - 2*min_len) * sizeof(u2));
1694 // Explicitly deallocate old operands array.
1695 // Note, it is not needed for 7u backport.
1696 if ( operands() != nullptr) { // the safety check
1697 MetadataFactory::free_array<u2>(loader_data, operands());
1698 }
1699 set_operands(new_ops);
1700 } // end resize_operands()
1701
1702
1703 // Extend the operands array with the length and size of the ext_cp operands.
1704 // Used in RedefineClasses for CP merge.
1705 void ConstantPool::extend_operands(const constantPoolHandle& ext_cp, TRAPS) {
1706 int delta_len = operand_array_length(ext_cp->operands());
1707 if (delta_len == 0) {
1708 return; // nothing to do
1709 }
1710 int delta_size = ext_cp->operands()->length();
1711
1712 assert(delta_len > 0 && delta_size > 0, "extended operands array must be bigger");
1713
1714 if (operand_array_length(operands()) == 0) {
1715 ClassLoaderData* loader_data = pool_holder()->class_loader_data();
1716 Array<u2>* new_ops = MetadataFactory::new_array<u2>(loader_data, delta_size, CHECK);
1717 // The first element index defines the offset of second part
1718 operand_offset_at_put(new_ops, 0, 2*delta_len); // offset in new array
1719 set_operands(new_ops);
1720 } else {
1721 resize_operands(delta_len, delta_size, CHECK);
1722 }
1723
1724 } // end extend_operands()
1725
1726
1727 // Shrink the operands array to a smaller array with new_len length.
1728 // Used in RedefineClasses for CP merge.
1729 void ConstantPool::shrink_operands(int new_len, TRAPS) {
1730 int old_len = operand_array_length(operands());
1731 if (new_len == old_len) {
1732 return; // nothing to do
1733 }
1734 assert(new_len < old_len, "shrunken operands array must be smaller");
1735
1736 int free_base = operand_next_offset_at(new_len - 1);
1737 int delta_len = new_len - old_len;
1738 int delta_size = 2*delta_len + free_base - operands()->length();
1739
1740 resize_operands(delta_len, delta_size, CHECK);
1741
1742 } // end shrink_operands()
1743
1744
1745 void ConstantPool::copy_operands(const constantPoolHandle& from_cp,
1746 const constantPoolHandle& to_cp,
1747 TRAPS) {
1748
1749 int from_oplen = operand_array_length(from_cp->operands());
1750 int old_oplen = operand_array_length(to_cp->operands());
1751 if (from_oplen != 0) {
1752 ClassLoaderData* loader_data = to_cp->pool_holder()->class_loader_data();
1753 // append my operands to the target's operands array
1754 if (old_oplen == 0) {
1755 // Can't just reuse from_cp's operand list because of deallocation issues
1756 int len = from_cp->operands()->length();
1757 Array<u2>* new_ops = MetadataFactory::new_array<u2>(loader_data, len, CHECK);
1758 Copy::conjoint_memory_atomic(
1759 from_cp->operands()->adr_at(0), new_ops->adr_at(0), len * sizeof(u2));
1760 to_cp->set_operands(new_ops);
1761 } else {
1762 int old_len = to_cp->operands()->length();
1763 int from_len = from_cp->operands()->length();
1764 int old_off = old_oplen * sizeof(u2);
1765 int from_off = from_oplen * sizeof(u2);
1766 // Use the metaspace for the destination constant pool
1767 Array<u2>* new_operands = MetadataFactory::new_array<u2>(loader_data, old_len + from_len, CHECK);
1768 int fillp = 0, len = 0;
1769 // first part of dest
1770 Copy::conjoint_memory_atomic(to_cp->operands()->adr_at(0),
1771 new_operands->adr_at(fillp),
1772 (len = old_off) * sizeof(u2));
1773 fillp += len;
1774 // first part of src
1775 Copy::conjoint_memory_atomic(from_cp->operands()->adr_at(0),
1776 new_operands->adr_at(fillp),
1777 (len = from_off) * sizeof(u2));
1778 fillp += len;
1779 // second part of dest
1780 Copy::conjoint_memory_atomic(to_cp->operands()->adr_at(old_off),
1781 new_operands->adr_at(fillp),
1782 (len = old_len - old_off) * sizeof(u2));
1783 fillp += len;
1784 // second part of src
1785 Copy::conjoint_memory_atomic(from_cp->operands()->adr_at(from_off),
1786 new_operands->adr_at(fillp),
1787 (len = from_len - from_off) * sizeof(u2));
1788 fillp += len;
1789 assert(fillp == new_operands->length(), "");
1790
1791 // Adjust indexes in the first part of the copied operands array.
1792 for (int j = 0; j < from_oplen; j++) {
1793 int offset = operand_offset_at(new_operands, old_oplen + j);
1794 assert(offset == operand_offset_at(from_cp->operands(), j), "correct copy");
1795 offset += old_len; // every new tuple is preceded by old_len extra u2's
1796 operand_offset_at_put(new_operands, old_oplen + j, offset);
1797 }
1798
1799 // replace target operands array with combined array
1800 to_cp->set_operands(new_operands);
1801 }
1802 }
1803 } // end copy_operands()
1804
1805
1806 // Copy this constant pool's entries at start_i to end_i (inclusive)
1807 // to the constant pool to_cp's entries starting at to_i. A total of
1808 // (end_i - start_i) + 1 entries are copied.
1809 void ConstantPool::copy_cp_to_impl(const constantPoolHandle& from_cp, int start_i, int end_i,
1810 const constantPoolHandle& to_cp, int to_i, TRAPS) {
1811
1812
1813 int dest_cpi = to_i; // leave original alone for debug purposes
1814
1815 for (int src_cpi = start_i; src_cpi <= end_i; /* see loop bottom */ ) {
1816 copy_entry_to(from_cp, src_cpi, to_cp, dest_cpi);
1817
1818 switch (from_cp->tag_at(src_cpi).value()) {
1819 case JVM_CONSTANT_Double:
1820 case JVM_CONSTANT_Long:
1821 // double and long take two constant pool entries
1822 src_cpi += 2;
1823 dest_cpi += 2;
1824 break;
1825
1826 default:
1827 // all others take one constant pool entry
1828 src_cpi++;
1829 dest_cpi++;
1830 break;
1831 }
1832 }
1833 copy_operands(from_cp, to_cp, CHECK);
1834
1835 } // end copy_cp_to_impl()
1836
1837
1838 // Copy this constant pool's entry at from_i to the constant pool
1839 // to_cp's entry at to_i.
1840 void ConstantPool::copy_entry_to(const constantPoolHandle& from_cp, int from_i,
1841 const constantPoolHandle& to_cp, int to_i) {
1842
1843 int tag = from_cp->tag_at(from_i).value();
1844 switch (tag) {
1845 case JVM_CONSTANT_ClassIndex:
1846 {
1847 jint ki = from_cp->klass_index_at(from_i);
1848 to_cp->klass_index_at_put(to_i, ki);
1849 } break;
1850
1851 case JVM_CONSTANT_Double:
1852 {
1853 jdouble d = from_cp->double_at(from_i);
1854 to_cp->double_at_put(to_i, d);
1855 // double takes two constant pool entries so init second entry's tag
1856 to_cp->tag_at_put(to_i + 1, JVM_CONSTANT_Invalid);
1857 } break;
1858
1859 case JVM_CONSTANT_Fieldref:
1860 {
1861 int class_index = from_cp->uncached_klass_ref_index_at(from_i);
1862 int name_and_type_index = from_cp->uncached_name_and_type_ref_index_at(from_i);
1863 to_cp->field_at_put(to_i, class_index, name_and_type_index);
1864 } break;
1865
1866 case JVM_CONSTANT_Float:
1867 {
1868 jfloat f = from_cp->float_at(from_i);
1869 to_cp->float_at_put(to_i, f);
1870 } break;
1871
1872 case JVM_CONSTANT_Integer:
1873 {
1874 jint i = from_cp->int_at(from_i);
1875 to_cp->int_at_put(to_i, i);
1876 } break;
1877
1878 case JVM_CONSTANT_InterfaceMethodref:
1879 {
1880 int class_index = from_cp->uncached_klass_ref_index_at(from_i);
1881 int name_and_type_index = from_cp->uncached_name_and_type_ref_index_at(from_i);
1882 to_cp->interface_method_at_put(to_i, class_index, name_and_type_index);
1883 } break;
1884
1885 case JVM_CONSTANT_Long:
1886 {
1887 jlong l = from_cp->long_at(from_i);
1888 to_cp->long_at_put(to_i, l);
1889 // long takes two constant pool entries so init second entry's tag
1890 to_cp->tag_at_put(to_i + 1, JVM_CONSTANT_Invalid);
1891 } break;
1892
1893 case JVM_CONSTANT_Methodref:
1894 {
1895 int class_index = from_cp->uncached_klass_ref_index_at(from_i);
1896 int name_and_type_index = from_cp->uncached_name_and_type_ref_index_at(from_i);
1897 to_cp->method_at_put(to_i, class_index, name_and_type_index);
1898 } break;
1899
1900 case JVM_CONSTANT_NameAndType:
1901 {
1902 int name_ref_index = from_cp->name_ref_index_at(from_i);
1903 int signature_ref_index = from_cp->signature_ref_index_at(from_i);
1904 to_cp->name_and_type_at_put(to_i, name_ref_index, signature_ref_index);
1905 } break;
1906
1907 case JVM_CONSTANT_StringIndex:
1908 {
1909 jint si = from_cp->string_index_at(from_i);
1910 to_cp->string_index_at_put(to_i, si);
1911 } break;
1912
1913 case JVM_CONSTANT_Class:
1914 case JVM_CONSTANT_UnresolvedClass:
1915 case JVM_CONSTANT_UnresolvedClassInError:
1916 {
1917 // Revert to JVM_CONSTANT_ClassIndex
1918 int name_index = from_cp->klass_slot_at(from_i).name_index();
1919 assert(from_cp->tag_at(name_index).is_symbol(), "sanity");
1920 to_cp->klass_index_at_put(to_i, name_index);
1921 } break;
1922
1923 case JVM_CONSTANT_String:
1924 {
1925 Symbol* s = from_cp->unresolved_string_at(from_i);
1926 to_cp->unresolved_string_at_put(to_i, s);
1927 } break;
1928
1929 case JVM_CONSTANT_Utf8:
1930 {
1931 Symbol* s = from_cp->symbol_at(from_i);
1932 // Need to increase refcount, the old one will be thrown away and deferenced
1933 s->increment_refcount();
1934 to_cp->symbol_at_put(to_i, s);
1935 } break;
1936
1937 case JVM_CONSTANT_MethodType:
1938 case JVM_CONSTANT_MethodTypeInError:
1939 {
1940 jint k = from_cp->method_type_index_at(from_i);
1941 to_cp->method_type_index_at_put(to_i, k);
1942 } break;
1943
1944 case JVM_CONSTANT_MethodHandle:
1945 case JVM_CONSTANT_MethodHandleInError:
1946 {
1947 int k1 = from_cp->method_handle_ref_kind_at(from_i);
1948 int k2 = from_cp->method_handle_index_at(from_i);
1949 to_cp->method_handle_index_at_put(to_i, k1, k2);
1950 } break;
1951
1952 case JVM_CONSTANT_Dynamic:
1953 case JVM_CONSTANT_DynamicInError:
1954 {
1955 int k1 = from_cp->bootstrap_methods_attribute_index(from_i);
1956 int k2 = from_cp->bootstrap_name_and_type_ref_index_at(from_i);
1957 k1 += operand_array_length(to_cp->operands()); // to_cp might already have operands
1958 to_cp->dynamic_constant_at_put(to_i, k1, k2);
1959 } break;
1960
1961 case JVM_CONSTANT_InvokeDynamic:
1962 {
1963 int k1 = from_cp->bootstrap_methods_attribute_index(from_i);
1964 int k2 = from_cp->bootstrap_name_and_type_ref_index_at(from_i);
1965 k1 += operand_array_length(to_cp->operands()); // to_cp might already have operands
1966 to_cp->invoke_dynamic_at_put(to_i, k1, k2);
1967 } break;
1968
1969 // Invalid is used as the tag for the second constant pool entry
1970 // occupied by JVM_CONSTANT_Double or JVM_CONSTANT_Long. It should
1971 // not be seen by itself.
1972 case JVM_CONSTANT_Invalid: // fall through
1973
1974 default:
1975 {
1976 ShouldNotReachHere();
1977 } break;
1978 }
1979 } // end copy_entry_to()
1980
1981 // Search constant pool search_cp for an entry that matches this
1982 // constant pool's entry at pattern_i. Returns the index of a
1983 // matching entry or zero (0) if there is no matching entry.
1984 int ConstantPool::find_matching_entry(int pattern_i,
1985 const constantPoolHandle& search_cp) {
1986
1987 // index zero (0) is not used
1988 for (int i = 1; i < search_cp->length(); i++) {
1989 bool found = compare_entry_to(pattern_i, search_cp, i);
1990 if (found) {
1991 return i;
1992 }
1993 }
1994
1995 return 0; // entry not found; return unused index zero (0)
1996 } // end find_matching_entry()
1997
1998
1999 // Compare this constant pool's bootstrap specifier at idx1 to the constant pool
2000 // cp2's bootstrap specifier at idx2.
2001 bool ConstantPool::compare_operand_to(int idx1, const constantPoolHandle& cp2, int idx2) {
2002 int k1 = operand_bootstrap_method_ref_index_at(idx1);
2003 int k2 = cp2->operand_bootstrap_method_ref_index_at(idx2);
2004 bool match = compare_entry_to(k1, cp2, k2);
2005
2006 if (!match) {
2007 return false;
2008 }
2009 int argc = operand_argument_count_at(idx1);
2010 if (argc == cp2->operand_argument_count_at(idx2)) {
2011 for (int j = 0; j < argc; j++) {
2012 k1 = operand_argument_index_at(idx1, j);
2013 k2 = cp2->operand_argument_index_at(idx2, j);
2014 match = compare_entry_to(k1, cp2, k2);
2015 if (!match) {
2016 return false;
2017 }
2018 }
2019 return true; // got through loop; all elements equal
2020 }
2021 return false;
2022 } // end compare_operand_to()
2023
2024 // Search constant pool search_cp for a bootstrap specifier that matches
2025 // this constant pool's bootstrap specifier data at pattern_i index.
2026 // Return the index of a matching bootstrap attribute record or (-1) if there is no match.
2027 int ConstantPool::find_matching_operand(int pattern_i,
2028 const constantPoolHandle& search_cp, int search_len) {
2029 for (int i = 0; i < search_len; i++) {
2030 bool found = compare_operand_to(pattern_i, search_cp, i);
2031 if (found) {
2032 return i;
2033 }
2034 }
2035 return -1; // bootstrap specifier data not found; return unused index (-1)
2036 } // end find_matching_operand()
2037
2038
2039 #ifndef PRODUCT
2040
2041 const char* ConstantPool::printable_name_at(int cp_index) {
2042
2043 constantTag tag = tag_at(cp_index);
2044
2045 if (tag.is_string()) {
2046 return string_at_noresolve(cp_index);
2047 } else if (tag.is_klass() || tag.is_unresolved_klass()) {
2048 return klass_name_at(cp_index)->as_C_string();
2049 } else if (tag.is_symbol()) {
2050 return symbol_at(cp_index)->as_C_string();
2051 }
2052 return "";
2053 }
2054
2055 #endif // PRODUCT
2056
2057
2058 // Returns size of constant pool entry.
2059 jint ConstantPool::cpool_entry_size(jint idx) {
2060 switch(tag_at(idx).value()) {
2061 case JVM_CONSTANT_Invalid:
2062 case JVM_CONSTANT_Unicode:
2063 return 1;
2064
2065 case JVM_CONSTANT_Utf8:
2066 return 3 + symbol_at(idx)->utf8_length();
2067
2068 case JVM_CONSTANT_Class:
2069 case JVM_CONSTANT_String:
2070 case JVM_CONSTANT_ClassIndex:
2071 case JVM_CONSTANT_UnresolvedClass:
2072 case JVM_CONSTANT_UnresolvedClassInError:
2073 case JVM_CONSTANT_StringIndex:
2074 case JVM_CONSTANT_MethodType:
2075 case JVM_CONSTANT_MethodTypeInError:
2076 return 3;
2077
2078 case JVM_CONSTANT_MethodHandle:
2079 case JVM_CONSTANT_MethodHandleInError:
2080 return 4; //tag, ref_kind, ref_index
2081
2082 case JVM_CONSTANT_Integer:
2083 case JVM_CONSTANT_Float:
2084 case JVM_CONSTANT_Fieldref:
2085 case JVM_CONSTANT_Methodref:
2086 case JVM_CONSTANT_InterfaceMethodref:
2087 case JVM_CONSTANT_NameAndType:
2088 return 5;
2089
2090 case JVM_CONSTANT_Dynamic:
2091 case JVM_CONSTANT_DynamicInError:
2092 case JVM_CONSTANT_InvokeDynamic:
2093 // u1 tag, u2 bsm, u2 nt
2094 return 5;
2095
2096 case JVM_CONSTANT_Long:
2097 case JVM_CONSTANT_Double:
2098 return 9;
2099 }
2100 assert(false, "cpool_entry_size: Invalid constant pool entry tag");
2101 return 1;
2102 } /* end cpool_entry_size */
2103
2104
2105 // SymbolHash is used to find a constant pool index from a string.
2106 // This function fills in SymbolHashs, one for utf8s and one for
2107 // class names, returns size of the cpool raw bytes.
2108 jint ConstantPool::hash_entries_to(SymbolHash *symmap,
2109 SymbolHash *classmap) {
2110 jint size = 0;
2111
2112 for (u2 idx = 1; idx < length(); idx++) {
2113 u2 tag = tag_at(idx).value();
2114 size += cpool_entry_size(idx);
2115
2116 switch(tag) {
2117 case JVM_CONSTANT_Utf8: {
2118 Symbol* sym = symbol_at(idx);
2119 symmap->add_if_absent(sym, idx);
2120 break;
2121 }
2122 case JVM_CONSTANT_Class:
2123 case JVM_CONSTANT_UnresolvedClass:
2124 case JVM_CONSTANT_UnresolvedClassInError: {
2125 Symbol* sym = klass_name_at(idx);
2126 classmap->add_if_absent(sym, idx);
2127 break;
2128 }
2129 case JVM_CONSTANT_Long:
2130 case JVM_CONSTANT_Double: {
2131 idx++; // Both Long and Double take two cpool slots
2132 break;
2133 }
2134 }
2135 }
2136 return size;
2137 } /* end hash_utf8_entries_to */
2138
2139
2140 // Copy cpool bytes.
2141 // Returns:
2142 // 0, in case of OutOfMemoryError
2143 // -1, in case of internal error
2144 // > 0, count of the raw cpool bytes that have been copied
2145 int ConstantPool::copy_cpool_bytes(int cpool_size,
2146 SymbolHash* tbl,
2147 unsigned char *bytes) {
2148 u2 idx1, idx2;
2149 jint size = 0;
2150 jint cnt = length();
2151 unsigned char *start_bytes = bytes;
2152
2153 for (jint idx = 1; idx < cnt; idx++) {
2154 u1 tag = tag_at(idx).value();
2155 jint ent_size = cpool_entry_size(idx);
2156
2157 assert(size + ent_size <= cpool_size, "Size mismatch");
2158
2159 *bytes = tag;
2160 switch(tag) {
2161 case JVM_CONSTANT_Invalid: {
2162 break;
2163 }
2164 case JVM_CONSTANT_Unicode: {
2165 assert(false, "Wrong constant pool tag: JVM_CONSTANT_Unicode");
2166 break;
2167 }
2168 case JVM_CONSTANT_Utf8: {
2169 Symbol* sym = symbol_at(idx);
2170 char* str = sym->as_utf8();
2171 // Warning! It's crashing on x86 with len = sym->utf8_length()
2172 int len = (int) strlen(str);
2173 Bytes::put_Java_u2((address) (bytes+1), (u2) len);
2174 for (int i = 0; i < len; i++) {
2175 bytes[3+i] = (u1) str[i];
2176 }
2177 break;
2178 }
2179 case JVM_CONSTANT_Integer: {
2180 jint val = int_at(idx);
2181 Bytes::put_Java_u4((address) (bytes+1), *(u4*)&val);
2182 break;
2183 }
2184 case JVM_CONSTANT_Float: {
2185 jfloat val = float_at(idx);
2186 Bytes::put_Java_u4((address) (bytes+1), *(u4*)&val);
2187 break;
2188 }
2189 case JVM_CONSTANT_Long: {
2190 jlong val = long_at(idx);
2191 Bytes::put_Java_u8((address) (bytes+1), *(u8*)&val);
2192 idx++; // Long takes two cpool slots
2193 break;
2194 }
2195 case JVM_CONSTANT_Double: {
2196 jdouble val = double_at(idx);
2197 Bytes::put_Java_u8((address) (bytes+1), *(u8*)&val);
2198 idx++; // Double takes two cpool slots
2199 break;
2200 }
2201 case JVM_CONSTANT_Class:
2202 case JVM_CONSTANT_UnresolvedClass:
2203 case JVM_CONSTANT_UnresolvedClassInError: {
2204 *bytes = JVM_CONSTANT_Class;
2205 Symbol* sym = klass_name_at(idx);
2206 idx1 = tbl->symbol_to_value(sym);
2207 assert(idx1 != 0, "Have not found a hashtable entry");
2208 Bytes::put_Java_u2((address) (bytes+1), idx1);
2209 break;
2210 }
2211 case JVM_CONSTANT_String: {
2212 *bytes = JVM_CONSTANT_String;
2213 Symbol* sym = unresolved_string_at(idx);
2214 idx1 = tbl->symbol_to_value(sym);
2215 assert(idx1 != 0, "Have not found a hashtable entry");
2216 Bytes::put_Java_u2((address) (bytes+1), idx1);
2217 break;
2218 }
2219 case JVM_CONSTANT_Fieldref:
2220 case JVM_CONSTANT_Methodref:
2221 case JVM_CONSTANT_InterfaceMethodref: {
2222 idx1 = uncached_klass_ref_index_at(idx);
2223 idx2 = uncached_name_and_type_ref_index_at(idx);
2224 Bytes::put_Java_u2((address) (bytes+1), idx1);
2225 Bytes::put_Java_u2((address) (bytes+3), idx2);
2226 break;
2227 }
2228 case JVM_CONSTANT_NameAndType: {
2229 idx1 = name_ref_index_at(idx);
2230 idx2 = signature_ref_index_at(idx);
2231 Bytes::put_Java_u2((address) (bytes+1), idx1);
2232 Bytes::put_Java_u2((address) (bytes+3), idx2);
2233 break;
2234 }
2235 case JVM_CONSTANT_ClassIndex: {
2236 *bytes = JVM_CONSTANT_Class;
2237 idx1 = checked_cast<u2>(klass_index_at(idx));
2238 Bytes::put_Java_u2((address) (bytes+1), idx1);
2239 break;
2240 }
2241 case JVM_CONSTANT_StringIndex: {
2242 *bytes = JVM_CONSTANT_String;
2243 idx1 = checked_cast<u2>(string_index_at(idx));
2244 Bytes::put_Java_u2((address) (bytes+1), idx1);
2245 break;
2246 }
2247 case JVM_CONSTANT_MethodHandle:
2248 case JVM_CONSTANT_MethodHandleInError: {
2249 *bytes = JVM_CONSTANT_MethodHandle;
2250 int kind = method_handle_ref_kind_at(idx);
2251 idx1 = checked_cast<u2>(method_handle_index_at(idx));
2252 *(bytes+1) = (unsigned char) kind;
2253 Bytes::put_Java_u2((address) (bytes+2), idx1);
2254 break;
2255 }
2256 case JVM_CONSTANT_MethodType:
2257 case JVM_CONSTANT_MethodTypeInError: {
2258 *bytes = JVM_CONSTANT_MethodType;
2259 idx1 = checked_cast<u2>(method_type_index_at(idx));
2260 Bytes::put_Java_u2((address) (bytes+1), idx1);
2261 break;
2262 }
2263 case JVM_CONSTANT_Dynamic:
2264 case JVM_CONSTANT_DynamicInError: {
2265 *bytes = tag;
2266 idx1 = extract_low_short_from_int(*int_at_addr(idx));
2267 idx2 = extract_high_short_from_int(*int_at_addr(idx));
2268 assert(idx2 == bootstrap_name_and_type_ref_index_at(idx), "correct half of u4");
2269 Bytes::put_Java_u2((address) (bytes+1), idx1);
2270 Bytes::put_Java_u2((address) (bytes+3), idx2);
2271 break;
2272 }
2273 case JVM_CONSTANT_InvokeDynamic: {
2274 *bytes = tag;
2275 idx1 = extract_low_short_from_int(*int_at_addr(idx));
2276 idx2 = extract_high_short_from_int(*int_at_addr(idx));
2277 assert(idx2 == bootstrap_name_and_type_ref_index_at(idx), "correct half of u4");
2278 Bytes::put_Java_u2((address) (bytes+1), idx1);
2279 Bytes::put_Java_u2((address) (bytes+3), idx2);
2280 break;
2281 }
2282 }
2283 bytes += ent_size;
2284 size += ent_size;
2285 }
2286 assert(size == cpool_size, "Size mismatch");
2287
2288 return (int)(bytes - start_bytes);
2289 } /* end copy_cpool_bytes */
2290
2291 bool ConstantPool::is_maybe_on_stack() const {
2292 // This method uses the similar logic as nmethod::is_maybe_on_stack()
2293 if (!Continuations::enabled()) {
2294 return false;
2295 }
2296
2297 // If the condition below is true, it means that the nmethod was found to
2298 // be alive the previous completed marking cycle.
2299 return cache()->gc_epoch() >= CodeCache::previous_completed_gc_marking_cycle();
2300 }
2301
2302 // For redefinition, if any methods found in loom stack chunks, the gc_epoch is
2303 // recorded in their constant pool cache. The on_stack-ness of the constant pool controls whether
2304 // memory for the method is reclaimed.
2305 bool ConstantPool::on_stack() const {
2306 if ((_flags &_on_stack) != 0) {
2307 return true;
2308 }
2309
2310 if (_cache == nullptr) {
2311 return false;
2312 }
2313
2314 return is_maybe_on_stack();
2315 }
2316
2317 void ConstantPool::set_on_stack(const bool value) {
2318 if (value) {
2319 // Only record if it's not already set.
2320 if (!on_stack()) {
2321 assert(!is_shared(), "should always be set for shared constant pools");
2322 _flags |= _on_stack;
2323 MetadataOnStackMark::record(this);
2324 }
2325 } else {
2326 // Clearing is done single-threadedly.
2327 if (!is_shared()) {
2328 _flags &= (u2)(~_on_stack);
2329 }
2330 }
2331 }
2332
2333 // Printing
2334
2335 void ConstantPool::print_on(outputStream* st) const {
2336 assert(is_constantPool(), "must be constantPool");
2337 st->print_cr("%s", internal_name());
2338 if (flags() != 0) {
2339 st->print(" - flags: 0x%x", flags());
2340 if (has_preresolution()) st->print(" has_preresolution");
2341 if (on_stack()) st->print(" on_stack");
2342 st->cr();
2343 }
2344 if (pool_holder() != nullptr) {
2345 st->print_cr(" - holder: " PTR_FORMAT, p2i(pool_holder()));
2346 }
2347 st->print_cr(" - cache: " PTR_FORMAT, p2i(cache()));
2348 st->print_cr(" - resolved_references: " PTR_FORMAT, p2i(resolved_references_or_null()));
2349 st->print_cr(" - reference_map: " PTR_FORMAT, p2i(reference_map()));
2350 st->print_cr(" - resolved_klasses: " PTR_FORMAT, p2i(resolved_klasses()));
2351 st->print_cr(" - cp length: %d", length());
2352
2353 for (int index = 1; index < length(); index++) { // Index 0 is unused
2354 ((ConstantPool*)this)->print_entry_on(index, st);
2355 switch (tag_at(index).value()) {
2356 case JVM_CONSTANT_Long :
2357 case JVM_CONSTANT_Double :
2358 index++; // Skip entry following eigth-byte constant
2359 }
2360
2361 }
2362 st->cr();
2363 }
2364
2365 // Print one constant pool entry
2366 void ConstantPool::print_entry_on(const int cp_index, outputStream* st) {
2367 EXCEPTION_MARK;
2368 st->print(" - %3d : ", cp_index);
2369 tag_at(cp_index).print_on(st);
2370 st->print(" : ");
2371 switch (tag_at(cp_index).value()) {
2372 case JVM_CONSTANT_Class :
2373 { Klass* k = klass_at(cp_index, CATCH);
2374 guarantee(k != nullptr, "need klass");
2375 k->print_value_on(st);
2376 st->print(" {" PTR_FORMAT "}", p2i(k));
2377 }
2378 break;
2379 case JVM_CONSTANT_Fieldref :
2380 case JVM_CONSTANT_Methodref :
2381 case JVM_CONSTANT_InterfaceMethodref :
2382 st->print("klass_index=%d", uncached_klass_ref_index_at(cp_index));
2383 st->print(" name_and_type_index=%d", uncached_name_and_type_ref_index_at(cp_index));
2384 break;
2385 case JVM_CONSTANT_String :
2386 unresolved_string_at(cp_index)->print_value_on(st);
2387 break;
2388 case JVM_CONSTANT_Integer :
2389 st->print("%d", int_at(cp_index));
2390 break;
2391 case JVM_CONSTANT_Float :
2392 st->print("%f", float_at(cp_index));
2393 break;
2394 case JVM_CONSTANT_Long :
2395 st->print_jlong(long_at(cp_index));
2396 break;
2397 case JVM_CONSTANT_Double :
2398 st->print("%lf", double_at(cp_index));
2399 break;
2400 case JVM_CONSTANT_NameAndType :
2401 st->print("name_index=%d", name_ref_index_at(cp_index));
2402 st->print(" signature_index=%d", signature_ref_index_at(cp_index));
2403 break;
2404 case JVM_CONSTANT_Utf8 :
2405 symbol_at(cp_index)->print_value_on(st);
2406 break;
2407 case JVM_CONSTANT_ClassIndex: {
2408 int name_index = *int_at_addr(cp_index);
2409 st->print("klass_index=%d ", name_index);
2410 symbol_at(name_index)->print_value_on(st);
2411 }
2412 break;
2413 case JVM_CONSTANT_UnresolvedClass : // fall-through
2414 case JVM_CONSTANT_UnresolvedClassInError: {
2415 CPKlassSlot kslot = klass_slot_at(cp_index);
2416 int resolved_klass_index = kslot.resolved_klass_index();
2417 int name_index = kslot.name_index();
2418 assert(tag_at(name_index).is_symbol(), "sanity");
2419 symbol_at(name_index)->print_value_on(st);
2420 }
2421 break;
2422 case JVM_CONSTANT_MethodHandle :
2423 case JVM_CONSTANT_MethodHandleInError :
2424 st->print("ref_kind=%d", method_handle_ref_kind_at(cp_index));
2425 st->print(" ref_index=%d", method_handle_index_at(cp_index));
2426 break;
2427 case JVM_CONSTANT_MethodType :
2428 case JVM_CONSTANT_MethodTypeInError :
2429 st->print("signature_index=%d", method_type_index_at(cp_index));
2430 break;
2431 case JVM_CONSTANT_Dynamic :
2432 case JVM_CONSTANT_DynamicInError :
2433 {
2434 st->print("bootstrap_method_index=%d", bootstrap_method_ref_index_at(cp_index));
2435 st->print(" type_index=%d", bootstrap_name_and_type_ref_index_at(cp_index));
2436 int argc = bootstrap_argument_count_at(cp_index);
2437 if (argc > 0) {
2438 for (int arg_i = 0; arg_i < argc; arg_i++) {
2439 int arg = bootstrap_argument_index_at(cp_index, arg_i);
2440 st->print((arg_i == 0 ? " arguments={%d" : ", %d"), arg);
2441 }
2442 st->print("}");
2443 }
2444 }
2445 break;
2446 case JVM_CONSTANT_InvokeDynamic :
2447 {
2448 st->print("bootstrap_method_index=%d", bootstrap_method_ref_index_at(cp_index));
2449 st->print(" name_and_type_index=%d", bootstrap_name_and_type_ref_index_at(cp_index));
2450 int argc = bootstrap_argument_count_at(cp_index);
2451 if (argc > 0) {
2452 for (int arg_i = 0; arg_i < argc; arg_i++) {
2453 int arg = bootstrap_argument_index_at(cp_index, arg_i);
2454 st->print((arg_i == 0 ? " arguments={%d" : ", %d"), arg);
2455 }
2456 st->print("}");
2457 }
2458 }
2459 break;
2460 default:
2461 ShouldNotReachHere();
2462 break;
2463 }
2464 st->cr();
2465 }
2466
2467 void ConstantPool::print_value_on(outputStream* st) const {
2468 assert(is_constantPool(), "must be constantPool");
2469 st->print("constant pool [%d]", length());
2470 if (has_preresolution()) st->print("/preresolution");
2471 if (operands() != nullptr) st->print("/operands[%d]", operands()->length());
2472 print_address_on(st);
2473 if (pool_holder() != nullptr) {
2474 st->print(" for ");
2475 pool_holder()->print_value_on(st);
2476 bool extra = (pool_holder()->constants() != this);
2477 if (extra) st->print(" (extra)");
2478 }
2479 if (cache() != nullptr) {
2480 st->print(" cache=" PTR_FORMAT, p2i(cache()));
2481 }
2482 }
2483
2484 // Verification
2485
2486 void ConstantPool::verify_on(outputStream* st) {
2487 guarantee(is_constantPool(), "object must be constant pool");
2488 for (int i = 0; i< length(); i++) {
2489 constantTag tag = tag_at(i);
2490 if (tag.is_klass() || tag.is_unresolved_klass()) {
2491 guarantee(klass_name_at(i)->refcount() != 0, "should have nonzero reference count");
2492 } else if (tag.is_symbol()) {
2493 Symbol* entry = symbol_at(i);
2494 guarantee(entry->refcount() != 0, "should have nonzero reference count");
2495 } else if (tag.is_string()) {
2496 Symbol* entry = unresolved_string_at(i);
2497 guarantee(entry->refcount() != 0, "should have nonzero reference count");
2498 }
2499 }
2500 if (pool_holder() != nullptr) {
2501 // Note: pool_holder() can be null in temporary constant pools
2502 // used during constant pool merging
2503 guarantee(pool_holder()->is_klass(), "should be klass");
2504 }
2505 }