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