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