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/cdsConfig.hpp"
28 #include "cds/heapShared.inline.hpp"
29 #include "classfile/classLoader.hpp"
30 #include "classfile/classLoaderData.hpp"
31 #include "classfile/javaClasses.inline.hpp"
32 #include "classfile/metadataOnStackMark.hpp"
33 #include "classfile/stringTable.hpp"
34 #include "classfile/systemDictionary.hpp"
35 #include "classfile/systemDictionaryShared.hpp"
36 #include "classfile/vmClasses.hpp"
37 #include "classfile/vmSymbols.hpp"
38 #include "code/codeCache.hpp"
39 #include "interpreter/bootstrapInfo.hpp"
40 #include "interpreter/linkResolver.hpp"
41 #include "jvm.h"
42 #include "logging/log.hpp"
43 #include "logging/logStream.hpp"
44 #include "memory/allocation.inline.hpp"
45 #include "memory/metadataFactory.hpp"
46 #include "memory/metaspaceClosure.hpp"
47 #include "memory/oopFactory.hpp"
48 #include "memory/resourceArea.hpp"
49 #include "memory/universe.hpp"
50 #include "oops/array.hpp"
51 #include "oops/constantPool.inline.hpp"
52 #include "oops/cpCache.inline.hpp"
53 #include "oops/fieldStreams.inline.hpp"
54 #include "oops/instanceKlass.hpp"
55 #include "oops/klass.inline.hpp"
56 #include "oops/objArrayKlass.hpp"
57 #include "oops/objArrayOop.inline.hpp"
58 #include "oops/oop.inline.hpp"
59 #include "oops/typeArrayOop.inline.hpp"
60 #include "prims/jvmtiExport.hpp"
61 #include "runtime/atomicAccess.hpp"
62 #include "runtime/fieldDescriptor.inline.hpp"
63 #include "runtime/handles.inline.hpp"
64 #include "runtime/init.hpp"
65 #include "runtime/javaCalls.hpp"
66 #include "runtime/javaThread.inline.hpp"
67 #include "runtime/perfData.hpp"
68 #include "runtime/signature.hpp"
69 #include "runtime/vframe.inline.hpp"
70 #include "utilities/checkedCast.hpp"
71 #include "utilities/copy.hpp"
72
73 ConstantPool* ConstantPool::allocate(ClassLoaderData* loader_data, int length, TRAPS) {
74 Array<u1>* tags = MetadataFactory::new_array<u1>(loader_data, length, 0, CHECK_NULL);
75 int size = ConstantPool::size(length);
76 return new (loader_data, size, MetaspaceObj::ConstantPoolType, THREAD) ConstantPool(tags);
77 }
78
79 void ConstantPool::copy_fields(const ConstantPool* orig) {
80 // Preserve dynamic constant information from the original pool
81 if (orig->has_dynamic_constant()) {
82 set_has_dynamic_constant();
83 }
84
85 set_major_version(orig->major_version());
86 set_minor_version(orig->minor_version());
87
88 set_source_file_name_index(orig->source_file_name_index());
89 set_generic_signature_index(orig->generic_signature_index());
90 }
91
92 #ifdef ASSERT
93
94 // MetaspaceObj allocation invariant is calloc equivalent memory
95 // simple verification of this here (JVM_CONSTANT_Invalid == 0 )
96 static bool tag_array_is_zero_initialized(Array<u1>* tags) {
97 assert(tags != nullptr, "invariant");
98 const int length = tags->length();
99 for (int index = 0; index < length; ++index) {
100 if (JVM_CONSTANT_Invalid != tags->at(index)) {
101 return false;
102 }
103 }
104 return true;
105 }
106
107 #endif
108
109 ConstantPool::ConstantPool() {
110 assert(CDSConfig::is_dumping_static_archive() || CDSConfig::is_using_archive(), "only for CDS");
111 }
112
113 ConstantPool::ConstantPool(Array<u1>* tags) :
114 _tags(tags),
115 _length(tags->length()) {
116
117 assert(_tags != nullptr, "invariant");
118 assert(tags->length() == _length, "invariant");
119 assert(tag_array_is_zero_initialized(tags), "invariant");
120 assert(0 == flags(), "invariant");
121 assert(0 == version(), "invariant");
122 assert(nullptr == _pool_holder, "invariant");
123 }
124
125 void ConstantPool::deallocate_contents(ClassLoaderData* loader_data) {
126 if (cache() != nullptr) {
127 MetadataFactory::free_metadata(loader_data, cache());
128 set_cache(nullptr);
129 }
130
131 MetadataFactory::free_array<Klass*>(loader_data, resolved_klasses());
132 set_resolved_klasses(nullptr);
133
134 bsm_entries().deallocate_contents(loader_data);
135
136 release_C_heap_structures();
137
138 // free tag array
139 MetadataFactory::free_array<u1>(loader_data, tags());
140 set_tags(nullptr);
141 }
142
143 void ConstantPool::release_C_heap_structures() {
144 // walk constant pool and decrement symbol reference counts
145 unreference_symbols();
146 }
147
148 void ConstantPool::metaspace_pointers_do(MetaspaceClosure* it) {
149 log_trace(aot)("Iter(ConstantPool): %p", this);
150
151 it->push(&_tags, MetaspaceClosure::_writable);
152 it->push(&_cache);
153 it->push(&_pool_holder);
154 it->push(&bsm_entries().offsets());
155 it->push(&bsm_entries().bootstrap_methods());
156 it->push(&_resolved_klasses, MetaspaceClosure::_writable);
157
158 for (int i = 0; i < length(); i++) {
159 // The only MSO's embedded in the CP entries are Symbols:
160 // JVM_CONSTANT_String
161 // JVM_CONSTANT_Utf8
162 constantTag ctag = tag_at(i);
163 if (ctag.is_string() || ctag.is_utf8()) {
164 it->push(symbol_at_addr(i));
165 }
166 }
167 }
168
169 objArrayOop ConstantPool::resolved_references() const {
170 return _cache->resolved_references();
171 }
172
173 // Called from outside constant pool resolution where a resolved_reference array
174 // may not be present.
175 objArrayOop ConstantPool::resolved_references_or_null() const {
176 if (_cache == nullptr) {
177 return nullptr;
178 } else {
179 return _cache->resolved_references();
180 }
181 }
182
183 oop ConstantPool::resolved_reference_at(int index) const {
184 oop result = resolved_references()->obj_at(index);
185 assert(oopDesc::is_oop_or_null(result), "Must be oop");
186 return result;
187 }
188
189 // Use a CAS for multithreaded access
190 oop ConstantPool::set_resolved_reference_at(int index, oop new_result) {
191 assert(oopDesc::is_oop_or_null(new_result), "Must be oop");
192 return resolved_references()->replace_if_null(index, new_result);
193 }
194
195 // Create resolved_references array and mapping array for original cp indexes
196 // The ldc bytecode was rewritten to have the resolved reference array index so need a way
197 // to map it back for resolving and some unlikely miscellaneous uses.
198 // The objects created by invokedynamic are appended to this list.
199 void ConstantPool::initialize_resolved_references(ClassLoaderData* loader_data,
200 const intStack& reference_map,
201 int constant_pool_map_length,
202 TRAPS) {
203 // Initialized the resolved object cache.
204 int map_length = reference_map.length();
205 if (map_length > 0) {
206 // Only need mapping back to constant pool entries. The map isn't used for
207 // invokedynamic resolved_reference entries. For invokedynamic entries,
208 // the constant pool cache index has the mapping back to both the constant
209 // pool and to the resolved reference index.
210 if (constant_pool_map_length > 0) {
211 Array<u2>* om = MetadataFactory::new_array<u2>(loader_data, constant_pool_map_length, CHECK);
212
213 for (int i = 0; i < constant_pool_map_length; i++) {
214 int x = reference_map.at(i);
215 assert(x == (int)(jushort) x, "klass index is too big");
216 om->at_put(i, (jushort)x);
217 }
218 set_reference_map(om);
219 }
220
221 // Create Java array for holding resolved strings, methodHandles,
222 // methodTypes, invokedynamic and invokehandle appendix objects, etc.
223 objArrayOop stom = oopFactory::new_objArray(vmClasses::Object_klass(), map_length, CHECK);
224 HandleMark hm(THREAD);
225 Handle refs_handle (THREAD, stom); // must handleize.
226 set_resolved_references(loader_data->add_handle(refs_handle));
227
228 // Create a "scratch" copy of the resolved references array to archive
229 if (CDSConfig::is_dumping_heap()) {
230 objArrayOop scratch_references = oopFactory::new_objArray(vmClasses::Object_klass(), map_length, CHECK);
231 HeapShared::add_scratch_resolved_references(this, scratch_references);
232 }
233 }
234 }
235
236 void ConstantPool::allocate_resolved_klasses(ClassLoaderData* loader_data, int num_klasses, TRAPS) {
237 // A ConstantPool can't possibly have 0xffff valid class entries,
238 // because entry #0 must be CONSTANT_Invalid, and each class entry must refer to a UTF8
239 // entry for the class's name. So at most we will have 0xfffe class entries.
240 // This allows us to use 0xffff (ConstantPool::_temp_resolved_klass_index) to indicate
241 // UnresolvedKlass entries that are temporarily created during class redefinition.
242 assert(num_klasses < CPKlassSlot::_temp_resolved_klass_index, "sanity");
243 assert(resolved_klasses() == nullptr, "sanity");
244 Array<Klass*>* rk = MetadataFactory::new_array<Klass*>(loader_data, num_klasses, CHECK);
245 set_resolved_klasses(rk);
246 }
247
248 void ConstantPool::initialize_unresolved_klasses(ClassLoaderData* loader_data, TRAPS) {
249 int len = length();
250 int num_klasses = 0;
251 for (int i = 1; i <len; i++) {
252 switch (tag_at(i).value()) {
253 case JVM_CONSTANT_ClassIndex:
254 {
255 const int class_index = klass_index_at(i);
256 unresolved_klass_at_put(i, class_index, num_klasses++);
257 }
258 break;
259 #ifndef PRODUCT
260 case JVM_CONSTANT_Class:
261 case JVM_CONSTANT_UnresolvedClass:
262 case JVM_CONSTANT_UnresolvedClassInError:
263 // All of these should have been reverted back to ClassIndex before calling
264 // this function.
265 ShouldNotReachHere();
266 #endif
267 }
268 }
269 allocate_resolved_klasses(loader_data, num_klasses, THREAD);
270 }
271
272 // Hidden class support:
273 void ConstantPool::klass_at_put(int class_index, Klass* k) {
274 assert(k != nullptr, "must be valid klass");
275 CPKlassSlot kslot = klass_slot_at(class_index);
276 int resolved_klass_index = kslot.resolved_klass_index();
277 Klass** adr = resolved_klasses()->adr_at(resolved_klass_index);
278 AtomicAccess::release_store(adr, k);
279
280 // The interpreter assumes when the tag is stored, the klass is resolved
281 // and the Klass* non-null, so we need hardware store ordering here.
282 release_tag_at_put(class_index, JVM_CONSTANT_Class);
283 }
284
285 #if INCLUDE_CDS_JAVA_HEAP
286 template <typename Function>
287 void ConstantPool::iterate_archivable_resolved_references(Function function) {
288 objArrayOop rr = resolved_references();
289 if (rr != nullptr && cache() != nullptr && CDSConfig::is_dumping_method_handles()) {
290 Array<ResolvedIndyEntry>* indy_entries = cache()->resolved_indy_entries();
291 if (indy_entries != nullptr) {
292 for (int i = 0; i < indy_entries->length(); i++) {
293 ResolvedIndyEntry *rie = indy_entries->adr_at(i);
294 if (rie->is_resolved() && AOTConstantPoolResolver::is_resolution_deterministic(this, rie->constant_pool_index())) {
295 int rr_index = rie->resolved_references_index();
296 assert(resolved_reference_at(rr_index) != nullptr, "must exist");
297 function(rr_index);
298
299 // Save the BSM as well (sometimes the JIT looks up the BSM it for replay)
300 int indy_cp_index = rie->constant_pool_index();
301 int bsm_mh_cp_index = bootstrap_method_ref_index_at(indy_cp_index);
302 int bsm_rr_index = cp_to_object_index(bsm_mh_cp_index);
303 assert(resolved_reference_at(bsm_rr_index) != nullptr, "must exist");
304 function(bsm_rr_index);
305 }
306 }
307 }
308
309 Array<ResolvedMethodEntry>* method_entries = cache()->resolved_method_entries();
310 if (method_entries != nullptr) {
311 for (int i = 0; i < method_entries->length(); i++) {
312 ResolvedMethodEntry* rme = method_entries->adr_at(i);
313 const char* rejection_reason = nullptr;
314 if (rme->is_resolved(Bytecodes::_invokehandle) && rme->has_appendix() &&
315 cache()->can_archive_resolved_method(this, rme, rejection_reason)) {
316 int rr_index = rme->resolved_references_index();
317 assert(resolved_reference_at(rr_index) != nullptr, "must exist");
318 function(rr_index);
319 }
320 }
321 }
322 }
323 }
324
325 // Returns the _resolved_reference array after removing unarchivable items from it.
326 // Returns null if this class is not supported, or _resolved_reference doesn't exist.
327 objArrayOop ConstantPool::prepare_resolved_references_for_archiving() {
328 if (_cache == nullptr) {
329 return nullptr; // nothing to do
330 }
331
332 InstanceKlass *ik = pool_holder();
333 if (!SystemDictionaryShared::is_builtin_loader(ik->class_loader_data())) {
334 // Archiving resolved references for classes from non-builtin loaders
335 // is not yet supported.
336 return nullptr;
337 }
338
339 objArrayOop rr = resolved_references();
340 if (rr != nullptr) {
341 ResourceMark rm;
342 int rr_len = rr->length();
343 GrowableArray<bool> keep_resolved_refs(rr_len, rr_len, false);
344
345 iterate_archivable_resolved_references([&](int rr_index) {
346 keep_resolved_refs.at_put(rr_index, true);
347 });
348
349 objArrayOop scratch_rr = HeapShared::scratch_resolved_references(this);
350 Array<u2>* ref_map = reference_map();
351 int ref_map_len = ref_map == nullptr ? 0 : ref_map->length();
352 for (int i = 0; i < rr_len; i++) {
353 oop obj = rr->obj_at(i);
354 scratch_rr->obj_at_put(i, nullptr);
355 if (obj != nullptr) {
356 if (i < ref_map_len) {
357 int index = object_to_cp_index(i);
358 if (tag_at(index).is_string()) {
359 assert(java_lang_String::is_instance(obj), "must be");
360 if (!HeapShared::is_string_too_large_to_archive(obj)) {
361 scratch_rr->obj_at_put(i, obj);
362 }
363 continue;
364 }
365 }
366
367 if (keep_resolved_refs.at(i)) {
368 scratch_rr->obj_at_put(i, obj);
369 }
370 }
371 }
372 return scratch_rr;
373 }
374 return rr;
375 }
376 #endif
377
378 #if INCLUDE_CDS
379 // CDS support. Create a new resolved_references array.
380 void ConstantPool::restore_unshareable_info(TRAPS) {
381 if (!_pool_holder->is_linked() && !_pool_holder->is_rewritten()) {
382 return;
383 }
384 assert(is_constantPool(), "ensure C++ vtable is restored");
385 assert(on_stack(), "should always be set for constant pools in AOT cache");
386 assert(in_aot_cache(), "should always be set for constant pools in AOT cache");
387 if (is_for_method_handle_intrinsic()) {
388 // See the same check in remove_unshareable_info() below.
389 assert(cache() == nullptr, "must not have cpCache");
390 return;
391 }
392 assert(_cache != nullptr, "constant pool _cache should not be null");
393
394 // Only create the new resolved references array if it hasn't been attempted before
395 if (resolved_references() != nullptr) return;
396
397 if (vmClasses::Object_klass_is_loaded()) {
398 ClassLoaderData* loader_data = pool_holder()->class_loader_data();
399 #if INCLUDE_CDS_JAVA_HEAP
400 if (HeapShared::is_archived_heap_in_use() &&
401 _cache->archived_references() != nullptr) {
402 oop archived = _cache->archived_references();
403 // Create handle for the archived resolved reference array object
404 HandleMark hm(THREAD);
405 Handle refs_handle(THREAD, archived);
406 set_resolved_references(loader_data->add_handle(refs_handle));
407 _cache->clear_archived_references();
408 } else
409 #endif
410 {
411 // No mapped archived resolved reference array
412 // Recreate the object array and add to ClassLoaderData.
413 int map_length = resolved_reference_length();
414 if (map_length > 0) {
415 objArrayOop stom = oopFactory::new_objArray(vmClasses::Object_klass(), map_length, CHECK);
416 HandleMark hm(THREAD);
417 Handle refs_handle(THREAD, stom); // must handleize.
418 set_resolved_references(loader_data->add_handle(refs_handle));
419 }
420 }
421 }
422
423 if (CDSConfig::is_dumping_final_static_archive() && CDSConfig::is_dumping_heap() && resolved_references() != nullptr) {
424 objArrayOop scratch_references = oopFactory::new_objArray(vmClasses::Object_klass(), resolved_references()->length(), CHECK);
425 HeapShared::add_scratch_resolved_references(this, scratch_references);
426 }
427 }
428
429 void ConstantPool::remove_unshareable_info() {
430 // ConstantPools in AOT cache are in the RO region, so the _flags cannot be modified.
431 // The _on_stack flag is used to prevent ConstantPools from deallocation during
432 // class redefinition. Since such ConstantPools cannot be deallocated anyway,
433 // we always set _on_stack to true to avoid having to change _flags during runtime.
434 _flags |= (_on_stack | _in_aot_cache);
435
436 if (is_for_method_handle_intrinsic()) {
437 // This CP was created by Method::make_method_handle_intrinsic() and has nothing
438 // that need to be removed/restored. It has no cpCache since the intrinsic methods
439 // don't have any bytecodes.
440 assert(cache() == nullptr, "must not have cpCache");
441 return;
442 }
443
444 bool update_resolved_reference = true;
445 if (CDSConfig::is_dumping_final_static_archive()) {
446 ConstantPool* src_cp = ArchiveBuilder::current()->get_source_addr(this);
447 InstanceKlass* src_holder = src_cp->pool_holder();
448 if (src_holder->defined_by_other_loaders()) {
449 // Unregistered classes are not loaded in the AOT assembly phase. The resolved reference length
450 // is already saved during the training run.
451 precond(!src_holder->is_loaded());
452 precond(resolved_reference_length() >= 0);
453 precond(resolved_references() == nullptr);
454 update_resolved_reference = false;
455 }
456 }
457
458 // resolved_references(): remember its length. If it cannot be restored
459 // from the archived heap objects at run time, we need to dynamically allocate it.
460 if (update_resolved_reference && cache() != nullptr) {
461 set_resolved_reference_length(
462 resolved_references() != nullptr ? resolved_references()->length() : 0);
463 set_resolved_references(OopHandle());
464 }
465 remove_unshareable_entries();
466 }
467
468 static const char* get_type(Klass* k) {
469 const char* type;
470 Klass* src_k;
471 if (ArchiveBuilder::is_active() && ArchiveBuilder::current()->is_in_buffer_space(k)) {
472 src_k = ArchiveBuilder::current()->get_source_addr(k);
473 } else {
474 src_k = k;
475 }
476
477 if (src_k->is_objArray_klass()) {
478 src_k = ObjArrayKlass::cast(src_k)->bottom_klass();
479 assert(!src_k->is_objArray_klass(), "sanity");
480 }
481
482 if (src_k->is_typeArray_klass()) {
483 type = "prim";
484 } else {
485 InstanceKlass* src_ik = InstanceKlass::cast(src_k);
486 if (src_ik->defined_by_boot_loader()) {
487 return "boot";
488 } else if (src_ik->defined_by_platform_loader()) {
489 return "plat";
490 } else if (src_ik->defined_by_app_loader()) {
491 return "app";
492 } else {
493 return "unreg";
494 }
495 }
496
497 return type;
498 }
499
500 void ConstantPool::remove_unshareable_entries() {
501 ResourceMark rm;
502 log_info(aot, resolve)("Archiving CP entries for %s", pool_holder()->name()->as_C_string());
503 for (int cp_index = 1; cp_index < length(); cp_index++) { // cp_index 0 is unused
504 int cp_tag = tag_at(cp_index).value();
505 switch (cp_tag) {
506 case JVM_CONSTANT_UnresolvedClass:
507 ArchiveBuilder::alloc_stats()->record_klass_cp_entry(false, false);
508 break;
509 case JVM_CONSTANT_UnresolvedClassInError:
510 tag_at_put(cp_index, JVM_CONSTANT_UnresolvedClass);
511 ArchiveBuilder::alloc_stats()->record_klass_cp_entry(false, true);
512 break;
513 case JVM_CONSTANT_MethodHandleInError:
514 tag_at_put(cp_index, JVM_CONSTANT_MethodHandle);
515 break;
516 case JVM_CONSTANT_MethodTypeInError:
517 tag_at_put(cp_index, JVM_CONSTANT_MethodType);
518 break;
519 case JVM_CONSTANT_DynamicInError:
520 tag_at_put(cp_index, JVM_CONSTANT_Dynamic);
521 break;
522 case JVM_CONSTANT_Class:
523 remove_resolved_klass_if_non_deterministic(cp_index);
524 break;
525 default:
526 break;
527 }
528 }
529
530 if (cache() != nullptr) {
531 // cache() is null if this class is not yet linked.
532 cache()->remove_unshareable_info();
533 }
534 }
535
536 void ConstantPool::remove_resolved_klass_if_non_deterministic(int cp_index) {
537 assert(ArchiveBuilder::current()->is_in_buffer_space(this), "must be");
538 assert(tag_at(cp_index).is_klass(), "must be resolved");
539
540 bool can_archive;
541 Klass* k = nullptr;
542
543 if (CDSConfig::is_dumping_preimage_static_archive()) {
544 can_archive = false;
545 } else {
546 k = resolved_klass_at(cp_index);
547 if (k == nullptr) {
548 // We'd come here if the referenced class has been excluded via
549 // SystemDictionaryShared::is_excluded_class(). As a result, ArchiveBuilder
550 // has cleared the resolved_klasses()->at(...) pointer to null. Thus, we
551 // need to revert the tag to JVM_CONSTANT_UnresolvedClass.
552 can_archive = false;
553 } else {
554 ConstantPool* src_cp = ArchiveBuilder::current()->get_source_addr(this);
555 can_archive = AOTConstantPoolResolver::is_resolution_deterministic(src_cp, cp_index);
556 }
557 }
558
559 if (!can_archive) {
560 int resolved_klass_index = klass_slot_at(cp_index).resolved_klass_index();
561 // This might be at a safepoint but do this in the right order.
562 tag_at_put(cp_index, JVM_CONSTANT_UnresolvedClass);
563 resolved_klasses()->at_put(resolved_klass_index, nullptr);
564 }
565
566 LogStreamHandle(Trace, aot, resolve) log;
567 if (log.is_enabled()) {
568 ResourceMark rm;
569 log.print("%s klass CP entry [%3d]: %s %s",
570 (can_archive ? "archived" : "reverted"),
571 cp_index, pool_holder()->name()->as_C_string(), get_type(pool_holder()));
572 if (can_archive) {
573 log.print(" => %s %s%s", k->name()->as_C_string(), get_type(k),
574 (!k->is_instance_klass() || pool_holder()->is_subtype_of(k)) ? "" : " (not supertype)");
575 } else {
576 Symbol* name = klass_name_at(cp_index);
577 log.print(" => %s", name->as_C_string());
578 }
579 }
580
581 ArchiveBuilder::alloc_stats()->record_klass_cp_entry(can_archive, /*reverted=*/!can_archive);
582 }
583 #endif // INCLUDE_CDS
584
585 int ConstantPool::cp_to_object_index(int cp_index) {
586 // this is harder don't do this so much.
587 int i = reference_map()->find(checked_cast<u2>(cp_index));
588 // We might not find the index for jsr292 call.
589 return (i < 0) ? _no_index_sentinel : i;
590 }
591
592 void ConstantPool::string_at_put(int obj_index, oop str) {
593 oop result = set_resolved_reference_at(obj_index, str);
594 assert(result == nullptr || result == str, "Only set once or to the same string.");
595 }
596
597 void ConstantPool::trace_class_resolution(const constantPoolHandle& this_cp, Klass* k) {
598 ResourceMark rm;
599 int line_number = -1;
600 const char * source_file = nullptr;
601 if (JavaThread::current()->has_last_Java_frame()) {
602 // try to identify the method which called this function.
603 vframeStream vfst(JavaThread::current());
604 if (!vfst.at_end()) {
605 line_number = vfst.method()->line_number_from_bci(vfst.bci());
606 Symbol* s = vfst.method()->method_holder()->source_file_name();
607 if (s != nullptr) {
608 source_file = s->as_C_string();
609 }
610 }
611 }
612 if (k != this_cp->pool_holder()) {
613 // only print something if the classes are different
614 if (source_file != nullptr) {
615 log_debug(class, resolve)("%s %s %s:%d",
616 this_cp->pool_holder()->external_name(),
617 k->external_name(), source_file, line_number);
618 } else {
619 log_debug(class, resolve)("%s %s",
620 this_cp->pool_holder()->external_name(),
621 k->external_name());
622 }
623 }
624 }
625
626 Klass* ConstantPool::klass_at_impl(const constantPoolHandle& this_cp, int cp_index,
627 TRAPS) {
628 JavaThread* javaThread = THREAD;
629
630 // A resolved constantPool entry will contain a Klass*, otherwise a Symbol*.
631 // It is not safe to rely on the tag bit's here, since we don't have a lock, and
632 // the entry and tag is not updated atomically.
633 CPKlassSlot kslot = this_cp->klass_slot_at(cp_index);
634 int resolved_klass_index = kslot.resolved_klass_index();
635 int name_index = kslot.name_index();
636 assert(this_cp->tag_at(name_index).is_symbol(), "sanity");
637
638 // The tag must be JVM_CONSTANT_Class in order to read the correct value from
639 // the unresolved_klasses() array.
640 if (this_cp->tag_at(cp_index).is_klass()) {
641 Klass* klass = this_cp->resolved_klasses()->at(resolved_klass_index);
642 assert(klass != nullptr, "must be resolved");
643 return klass;
644 }
645
646 // This tag doesn't change back to unresolved class unless at a safepoint.
647 if (this_cp->tag_at(cp_index).is_unresolved_klass_in_error()) {
648 // The original attempt to resolve this constant pool entry failed so find the
649 // class of the original error and throw another error of the same class
650 // (JVMS 5.4.3).
651 // If there is a detail message, pass that detail message to the error.
652 // The JVMS does not strictly require us to duplicate the same detail message,
653 // or any internal exception fields such as cause or stacktrace. But since the
654 // detail message is often a class name or other literal string, we will repeat it
655 // if we can find it in the symbol table.
656 throw_resolution_error(this_cp, cp_index, CHECK_NULL);
657 ShouldNotReachHere();
658 }
659
660 HandleMark hm(THREAD);
661 Handle mirror_handle;
662 Symbol* name = this_cp->symbol_at(name_index);
663 Handle loader (THREAD, this_cp->pool_holder()->class_loader());
664
665 Klass* k;
666 {
667 // Turn off the single stepping while doing class resolution
668 JvmtiHideSingleStepping jhss(javaThread);
669 k = SystemDictionary::resolve_or_fail(name, loader, true, THREAD);
670 } // JvmtiHideSingleStepping jhss(javaThread);
671
672 if (!HAS_PENDING_EXCEPTION) {
673 // preserve the resolved klass from unloading
674 mirror_handle = Handle(THREAD, k->java_mirror());
675 // Do access check for klasses
676 verify_constant_pool_resolve(this_cp, k, THREAD);
677 }
678
679 // Failed to resolve class. We must record the errors so that subsequent attempts
680 // to resolve this constant pool entry fail with the same error (JVMS 5.4.3).
681 if (HAS_PENDING_EXCEPTION) {
682 save_and_throw_exception(this_cp, cp_index, constantTag(JVM_CONSTANT_UnresolvedClass), CHECK_NULL);
683 // If CHECK_NULL above doesn't return the exception, that means that
684 // some other thread has beaten us and has resolved the class.
685 // To preserve old behavior, we return the resolved class.
686 Klass* klass = this_cp->resolved_klasses()->at(resolved_klass_index);
687 assert(klass != nullptr, "must be resolved if exception was cleared");
688 return klass;
689 }
690
691 // logging for class+resolve.
692 if (log_is_enabled(Debug, class, resolve)){
693 trace_class_resolution(this_cp, k);
694 }
695
696 // The interpreter assumes when the tag is stored, the klass is resolved
697 // and the Klass* stored in _resolved_klasses is non-null, so we need
698 // hardware store ordering here.
699 // We also need to CAS to not overwrite an error from a racing thread.
700 Klass** adr = this_cp->resolved_klasses()->adr_at(resolved_klass_index);
701 AtomicAccess::release_store(adr, k);
702
703 jbyte old_tag = AtomicAccess::cmpxchg((jbyte*)this_cp->tag_addr_at(cp_index),
704 (jbyte)JVM_CONSTANT_UnresolvedClass,
705 (jbyte)JVM_CONSTANT_Class);
706
707 // We need to recheck exceptions from racing thread and return the same.
708 if (old_tag == JVM_CONSTANT_UnresolvedClassInError) {
709 // Remove klass.
710 AtomicAccess::store(adr, (Klass*)nullptr);
711 throw_resolution_error(this_cp, cp_index, CHECK_NULL);
712 }
713
714 return k;
715 }
716
717
718 // Does not update ConstantPool* - to avoid any exception throwing. Used
719 // by compiler and exception handling. Also used to avoid classloads for
720 // instanceof operations. Returns null if the class has not been loaded or
721 // if the verification of constant pool failed
722 Klass* ConstantPool::klass_at_if_loaded(const constantPoolHandle& this_cp, int which) {
723 CPKlassSlot kslot = this_cp->klass_slot_at(which);
724 int resolved_klass_index = kslot.resolved_klass_index();
725 int name_index = kslot.name_index();
726 assert(this_cp->tag_at(name_index).is_symbol(), "sanity");
727
728 if (this_cp->tag_at(which).is_klass()) {
729 Klass* k = this_cp->resolved_klasses()->at(resolved_klass_index);
730 assert(k != nullptr, "must be resolved");
731 return k;
732 } else if (this_cp->tag_at(which).is_unresolved_klass_in_error()) {
733 return nullptr;
734 } else {
735 Thread* current = Thread::current();
736 HandleMark hm(current);
737 Symbol* name = this_cp->symbol_at(name_index);
738 oop loader = this_cp->pool_holder()->class_loader();
739 Handle h_loader (current, loader);
740 Klass* k = SystemDictionary::find_instance_klass(current, name, h_loader);
741
742 // Avoid constant pool verification at a safepoint, as it takes the Module_lock.
743 if (k != nullptr && current->is_Java_thread()) {
744 // Make sure that resolving is legal
745 JavaThread* THREAD = JavaThread::cast(current); // For exception macros.
746 ExceptionMark em(THREAD);
747 // return null if verification fails
748 verify_constant_pool_resolve(this_cp, k, THREAD);
749 if (HAS_PENDING_EXCEPTION) {
750 CLEAR_PENDING_EXCEPTION;
751 return nullptr;
752 }
753 return k;
754 } else {
755 return k;
756 }
757 }
758 }
759
760 Method* ConstantPool::method_at_if_loaded(const constantPoolHandle& cpool,
761 int which) {
762 if (cpool->cache() == nullptr) return nullptr; // nothing to load yet
763 if (!(which >= 0 && which < cpool->resolved_method_entries_length())) {
764 // FIXME: should be an assert
765 log_debug(class, resolve)("bad BSM %d in:", which); cpool->print();
766 return nullptr;
767 }
768 return cpool->cache()->method_if_resolved(which);
769 }
770
771
772 bool ConstantPool::has_appendix_at_if_loaded(const constantPoolHandle& cpool, int which, Bytecodes::Code code) {
773 if (cpool->cache() == nullptr) return false; // nothing to load yet
774 if (code == Bytecodes::_invokedynamic) {
775 return cpool->resolved_indy_entry_at(which)->has_appendix();
776 } else {
777 return cpool->resolved_method_entry_at(which)->has_appendix();
778 }
779 }
780
781 oop ConstantPool::appendix_at_if_loaded(const constantPoolHandle& cpool, int which, Bytecodes::Code code) {
782 if (cpool->cache() == nullptr) return nullptr; // nothing to load yet
783 if (code == Bytecodes::_invokedynamic) {
784 return cpool->resolved_reference_from_indy(which);
785 } else {
786 return cpool->cache()->appendix_if_resolved(which);
787 }
788 }
789
790
791 bool ConstantPool::has_local_signature_at_if_loaded(const constantPoolHandle& cpool, int which, Bytecodes::Code code) {
792 if (cpool->cache() == nullptr) return false; // nothing to load yet
793 if (code == Bytecodes::_invokedynamic) {
794 return cpool->resolved_indy_entry_at(which)->has_local_signature();
795 } else {
796 return cpool->resolved_method_entry_at(which)->has_local_signature();
797 }
798 }
799
800 // Translate index, which could be CPCache index or Indy index, to a constant pool index
801 int ConstantPool::to_cp_index(int index, Bytecodes::Code code) {
802 assert(cache() != nullptr, "'index' is a rewritten index so this class must have been rewritten");
803 switch(code) {
804 case Bytecodes::_invokedynamic:
805 return invokedynamic_bootstrap_ref_index_at(index);
806 case Bytecodes::_getfield:
807 case Bytecodes::_getstatic:
808 case Bytecodes::_putfield:
809 case Bytecodes::_putstatic:
810 return resolved_field_entry_at(index)->constant_pool_index();
811 case Bytecodes::_invokeinterface:
812 case Bytecodes::_invokehandle:
813 case Bytecodes::_invokespecial:
814 case Bytecodes::_invokestatic:
815 case Bytecodes::_invokevirtual:
816 case Bytecodes::_fast_invokevfinal: // Bytecode interpreter uses this
817 return resolved_method_entry_at(index)->constant_pool_index();
818 default:
819 fatal("Unexpected bytecode: %s", Bytecodes::name(code));
820 }
821 }
822
823 bool ConstantPool::is_resolved(int index, Bytecodes::Code code) {
824 assert(cache() != nullptr, "'index' is a rewritten index so this class must have been rewritten");
825 switch(code) {
826 case Bytecodes::_invokedynamic:
827 return resolved_indy_entry_at(index)->is_resolved();
828
829 case Bytecodes::_getfield:
830 case Bytecodes::_getstatic:
831 case Bytecodes::_putfield:
832 case Bytecodes::_putstatic:
833 return resolved_field_entry_at(index)->is_resolved(code);
834
835 case Bytecodes::_invokeinterface:
836 case Bytecodes::_invokehandle:
837 case Bytecodes::_invokespecial:
838 case Bytecodes::_invokestatic:
839 case Bytecodes::_invokevirtual:
840 case Bytecodes::_fast_invokevfinal: // Bytecode interpreter uses this
841 return resolved_method_entry_at(index)->is_resolved(code);
842
843 default:
844 fatal("Unexpected bytecode: %s", Bytecodes::name(code));
845 }
846 }
847
848 u2 ConstantPool::uncached_name_and_type_ref_index_at(int cp_index) {
849 if (tag_at(cp_index).has_bootstrap()) {
850 u2 pool_index = bootstrap_name_and_type_ref_index_at(cp_index);
851 assert(tag_at(pool_index).is_name_and_type(), "");
852 return pool_index;
853 }
854 assert(tag_at(cp_index).is_field_or_method(), "Corrupted constant pool");
855 assert(!tag_at(cp_index).has_bootstrap(), "Must be handled above");
856 jint ref_index = *int_at_addr(cp_index);
857 return extract_high_short_from_int(ref_index);
858 }
859
860 u2 ConstantPool::name_and_type_ref_index_at(int index, Bytecodes::Code code) {
861 return uncached_name_and_type_ref_index_at(to_cp_index(index, code));
862 }
863
864 constantTag ConstantPool::tag_ref_at(int which, Bytecodes::Code code) {
865 // which may be either a Constant Pool index or a rewritten index
866 int pool_index = which;
867 assert(cache() != nullptr, "'index' is a rewritten index so this class must have been rewritten");
868 pool_index = to_cp_index(which, code);
869 return tag_at(pool_index);
870 }
871
872 u2 ConstantPool::uncached_klass_ref_index_at(int cp_index) {
873 assert(tag_at(cp_index).is_field_or_method(), "Corrupted constant pool");
874 jint ref_index = *int_at_addr(cp_index);
875 return extract_low_short_from_int(ref_index);
876 }
877
878 u2 ConstantPool::klass_ref_index_at(int index, Bytecodes::Code code) {
879 assert(code != Bytecodes::_invokedynamic,
880 "an invokedynamic instruction does not have a klass");
881 return uncached_klass_ref_index_at(to_cp_index(index, code));
882 }
883
884 void ConstantPool::verify_constant_pool_resolve(const constantPoolHandle& this_cp, Klass* k, TRAPS) {
885 if (!(k->is_instance_klass() || k->is_objArray_klass())) {
886 return; // short cut, typeArray klass is always accessible
887 }
888 Klass* holder = this_cp->pool_holder();
889 LinkResolver::check_klass_accessibility(holder, k, CHECK);
890 }
891
892
893 u2 ConstantPool::name_ref_index_at(int cp_index) {
894 jint ref_index = name_and_type_at(cp_index);
895 return extract_low_short_from_int(ref_index);
896 }
897
898
899 u2 ConstantPool::signature_ref_index_at(int cp_index) {
900 jint ref_index = name_and_type_at(cp_index);
901 return extract_high_short_from_int(ref_index);
902 }
903
904
905 Klass* ConstantPool::klass_ref_at(int which, Bytecodes::Code code, TRAPS) {
906 return klass_at(klass_ref_index_at(which, code), THREAD);
907 }
908
909 Symbol* ConstantPool::klass_name_at(int cp_index) const {
910 return symbol_at(klass_slot_at(cp_index).name_index());
911 }
912
913 Symbol* ConstantPool::klass_ref_at_noresolve(int which, Bytecodes::Code code) {
914 jint ref_index = klass_ref_index_at(which, code);
915 return klass_at_noresolve(ref_index);
916 }
917
918 Symbol* ConstantPool::uncached_klass_ref_at_noresolve(int cp_index) {
919 jint ref_index = uncached_klass_ref_index_at(cp_index);
920 return klass_at_noresolve(ref_index);
921 }
922
923 char* ConstantPool::string_at_noresolve(int cp_index) {
924 return unresolved_string_at(cp_index)->as_C_string();
925 }
926
927 BasicType ConstantPool::basic_type_for_signature_at(int cp_index) const {
928 return Signature::basic_type(symbol_at(cp_index));
929 }
930
931
932 void ConstantPool::resolve_string_constants_impl(const constantPoolHandle& this_cp, TRAPS) {
933 for (int index = 1; index < this_cp->length(); index++) { // Index 0 is unused
934 if (this_cp->tag_at(index).is_string()) {
935 this_cp->string_at(index, CHECK);
936 }
937 }
938 }
939
940 static const char* exception_message(const constantPoolHandle& this_cp, int which, constantTag tag, oop pending_exception) {
941 // Note: caller needs ResourceMark
942
943 // Dig out the detailed message to reuse if possible
944 const char* msg = java_lang_Throwable::message_as_utf8(pending_exception);
945 if (msg != nullptr) {
946 return msg;
947 }
948
949 Symbol* message = nullptr;
950 // Return specific message for the tag
951 switch (tag.value()) {
952 case JVM_CONSTANT_UnresolvedClass:
953 // return the class name in the error message
954 message = this_cp->klass_name_at(which);
955 break;
956 case JVM_CONSTANT_MethodHandle:
957 // return the method handle name in the error message
958 message = this_cp->method_handle_name_ref_at(which);
959 break;
960 case JVM_CONSTANT_MethodType:
961 // return the method type signature in the error message
962 message = this_cp->method_type_signature_at(which);
963 break;
964 case JVM_CONSTANT_Dynamic:
965 // return the name of the condy in the error message
966 message = this_cp->uncached_name_ref_at(which);
967 break;
968 default:
969 ShouldNotReachHere();
970 }
971
972 return message != nullptr ? message->as_C_string() : nullptr;
973 }
974
975 static void add_resolution_error(JavaThread* current, const constantPoolHandle& this_cp, int which,
976 constantTag tag, oop pending_exception) {
977
978 ResourceMark rm(current);
979 Symbol* error = pending_exception->klass()->name();
980 oop cause = java_lang_Throwable::cause(pending_exception);
981
982 // Also dig out the exception cause, if present.
983 Symbol* cause_sym = nullptr;
984 const char* cause_msg = nullptr;
985 if (cause != nullptr && cause != pending_exception) {
986 cause_sym = cause->klass()->name();
987 cause_msg = java_lang_Throwable::message_as_utf8(cause);
988 }
989
990 const char* message = exception_message(this_cp, which, tag, pending_exception);
991 SystemDictionary::add_resolution_error(this_cp, which, error, message, cause_sym, cause_msg);
992 }
993
994
995 void ConstantPool::throw_resolution_error(const constantPoolHandle& this_cp, int which, TRAPS) {
996 ResourceMark rm(THREAD);
997 const char* message = nullptr;
998 Symbol* cause = nullptr;
999 const char* cause_msg = nullptr;
1000 Symbol* error = SystemDictionary::find_resolution_error(this_cp, which, &message, &cause, &cause_msg);
1001 assert(error != nullptr, "checking");
1002
1003 CLEAR_PENDING_EXCEPTION;
1004 if (message != nullptr) {
1005 if (cause != nullptr) {
1006 Handle h_cause = Exceptions::new_exception(THREAD, cause, cause_msg);
1007 THROW_MSG_CAUSE(error, message, h_cause);
1008 } else {
1009 THROW_MSG(error, message);
1010 }
1011 } else {
1012 if (cause != nullptr) {
1013 Handle h_cause = Exceptions::new_exception(THREAD, cause, cause_msg);
1014 THROW_CAUSE(error, h_cause);
1015 } else {
1016 THROW(error);
1017 }
1018 }
1019 }
1020
1021 // If resolution for Class, Dynamic constant, MethodHandle or MethodType fails, save the
1022 // exception in the resolution error table, so that the same exception is thrown again.
1023 void ConstantPool::save_and_throw_exception(const constantPoolHandle& this_cp, int cp_index,
1024 constantTag tag, TRAPS) {
1025
1026 int error_tag = tag.error_value();
1027
1028 if (!PENDING_EXCEPTION->
1029 is_a(vmClasses::LinkageError_klass())) {
1030 // Just throw the exception and don't prevent these classes from
1031 // being loaded due to virtual machine errors like StackOverflow
1032 // and OutOfMemoryError, etc, or if the thread was hit by stop()
1033 // Needs clarification to section 5.4.3 of the VM spec (see 6308271)
1034 } else if (this_cp->tag_at(cp_index).value() != error_tag) {
1035 add_resolution_error(THREAD, this_cp, cp_index, tag, PENDING_EXCEPTION);
1036 // CAS in the tag. If a thread beat us to registering this error that's fine.
1037 // If another thread resolved the reference, this is a race condition. This
1038 // thread may have had a security manager or something temporary.
1039 // This doesn't deterministically get an error. So why do we save this?
1040 // We save this because jvmti can add classes to the bootclass path after
1041 // this error, so it needs to get the same error if the error is first.
1042 jbyte old_tag = AtomicAccess::cmpxchg((jbyte*)this_cp->tag_addr_at(cp_index),
1043 (jbyte)tag.value(),
1044 (jbyte)error_tag);
1045 if (old_tag != error_tag && old_tag != tag.value()) {
1046 // MethodHandles and MethodType doesn't change to resolved version.
1047 assert(this_cp->tag_at(cp_index).is_klass(), "Wrong tag value");
1048 // Forget the exception and use the resolved class.
1049 CLEAR_PENDING_EXCEPTION;
1050 }
1051 } else {
1052 // some other thread put this in error state
1053 throw_resolution_error(this_cp, cp_index, CHECK);
1054 }
1055 }
1056
1057 constantTag ConstantPool::constant_tag_at(int cp_index) {
1058 constantTag tag = tag_at(cp_index);
1059 if (tag.is_dynamic_constant()) {
1060 BasicType bt = basic_type_for_constant_at(cp_index);
1061 return constantTag(constantTag::type2tag(bt));
1062 }
1063 return tag;
1064 }
1065
1066 BasicType ConstantPool::basic_type_for_constant_at(int cp_index) {
1067 constantTag tag = tag_at(cp_index);
1068 if (tag.is_dynamic_constant() ||
1069 tag.is_dynamic_constant_in_error()) {
1070 // have to look at the signature for this one
1071 Symbol* constant_type = uncached_signature_ref_at(cp_index);
1072 return Signature::basic_type(constant_type);
1073 }
1074 return tag.basic_type();
1075 }
1076
1077 // Called to resolve constants in the constant pool and return an oop.
1078 // Some constant pool entries cache their resolved oop. This is also
1079 // called to create oops from constants to use in arguments for invokedynamic
1080 oop ConstantPool::resolve_constant_at_impl(const constantPoolHandle& this_cp,
1081 int cp_index, int cache_index,
1082 bool* status_return, TRAPS) {
1083 oop result_oop = nullptr;
1084
1085 if (cache_index == _possible_index_sentinel) {
1086 // It is possible that this constant is one which is cached in the objects.
1087 // We'll do a linear search. This should be OK because this usage is rare.
1088 // FIXME: If bootstrap specifiers stress this code, consider putting in
1089 // a reverse index. Binary search over a short array should do it.
1090 assert(cp_index > 0, "valid constant pool index");
1091 cache_index = this_cp->cp_to_object_index(cp_index);
1092 }
1093 assert(cache_index == _no_index_sentinel || cache_index >= 0, "");
1094 assert(cp_index == _no_index_sentinel || cp_index >= 0, "");
1095
1096 if (cache_index >= 0) {
1097 result_oop = this_cp->resolved_reference_at(cache_index);
1098 if (result_oop != nullptr) {
1099 if (result_oop == Universe::the_null_sentinel()) {
1100 DEBUG_ONLY(int temp_index = (cp_index >= 0 ? cp_index : this_cp->object_to_cp_index(cache_index)));
1101 assert(this_cp->tag_at(temp_index).is_dynamic_constant(), "only condy uses the null sentinel");
1102 result_oop = nullptr;
1103 }
1104 if (status_return != nullptr) (*status_return) = true;
1105 return result_oop;
1106 // That was easy...
1107 }
1108 cp_index = this_cp->object_to_cp_index(cache_index);
1109 }
1110
1111 jvalue prim_value; // temp used only in a few cases below
1112
1113 constantTag tag = this_cp->tag_at(cp_index);
1114
1115 if (status_return != nullptr) {
1116 // don't trigger resolution if the constant might need it
1117 switch (tag.value()) {
1118 case JVM_CONSTANT_Class:
1119 assert(this_cp->resolved_klass_at(cp_index) != nullptr, "must be resolved");
1120 break;
1121 case JVM_CONSTANT_String:
1122 case JVM_CONSTANT_Integer:
1123 case JVM_CONSTANT_Float:
1124 case JVM_CONSTANT_Long:
1125 case JVM_CONSTANT_Double:
1126 // these guys trigger OOM at worst
1127 break;
1128 default:
1129 (*status_return) = false;
1130 return nullptr;
1131 }
1132 // from now on there is either success or an OOME
1133 (*status_return) = true;
1134 }
1135
1136 switch (tag.value()) {
1137
1138 case JVM_CONSTANT_UnresolvedClass:
1139 case JVM_CONSTANT_Class:
1140 {
1141 assert(cache_index == _no_index_sentinel, "should not have been set");
1142 Klass* resolved = klass_at_impl(this_cp, cp_index, CHECK_NULL);
1143 // ldc wants the java mirror.
1144 result_oop = resolved->java_mirror();
1145 break;
1146 }
1147
1148 case JVM_CONSTANT_Dynamic:
1149 { PerfTraceTimedEvent timer(ClassLoader::perf_resolve_invokedynamic_time(),
1150 ClassLoader::perf_resolve_invokedynamic_count());
1151
1152 // Resolve the Dynamically-Computed constant to invoke the BSM in order to obtain the resulting oop.
1153 BootstrapInfo bootstrap_specifier(this_cp, cp_index);
1154
1155 // The initial step in resolving an unresolved symbolic reference to a
1156 // dynamically-computed constant is to resolve the symbolic reference to a
1157 // method handle which will be the bootstrap method for the dynamically-computed
1158 // constant. If resolution of the java.lang.invoke.MethodHandle for the bootstrap
1159 // method fails, then a MethodHandleInError is stored at the corresponding
1160 // bootstrap method's CP index for the CONSTANT_MethodHandle_info. No need to
1161 // set a DynamicConstantInError here since any subsequent use of this
1162 // bootstrap method will encounter the resolution of MethodHandleInError.
1163 // Both the first, (resolution of the BSM and its static arguments), and the second tasks,
1164 // (invocation of the BSM), of JVMS Section 5.4.3.6 occur within invoke_bootstrap_method()
1165 // for the bootstrap_specifier created above.
1166 SystemDictionary::invoke_bootstrap_method(bootstrap_specifier, THREAD);
1167 Exceptions::wrap_dynamic_exception(/* is_indy */ false, THREAD);
1168 if (HAS_PENDING_EXCEPTION) {
1169 // Resolution failure of the dynamically-computed constant, save_and_throw_exception
1170 // will check for a LinkageError and store a DynamicConstantInError.
1171 save_and_throw_exception(this_cp, cp_index, tag, CHECK_NULL);
1172 }
1173 result_oop = bootstrap_specifier.resolved_value()();
1174 BasicType type = Signature::basic_type(bootstrap_specifier.signature());
1175 if (!is_reference_type(type)) {
1176 // Make sure the primitive value is properly boxed.
1177 // This is a JDK responsibility.
1178 const char* fail = nullptr;
1179 if (result_oop == nullptr) {
1180 fail = "null result instead of box";
1181 } else if (!is_java_primitive(type)) {
1182 // FIXME: support value types via unboxing
1183 fail = "can only handle references and primitives";
1184 } else if (!java_lang_boxing_object::is_instance(result_oop, type)) {
1185 fail = "primitive is not properly boxed";
1186 }
1187 if (fail != nullptr) {
1188 // Since this exception is not a LinkageError, throw exception
1189 // but do not save a DynamicInError resolution result.
1190 // See section 5.4.3 of the VM spec.
1191 THROW_MSG_NULL(vmSymbols::java_lang_InternalError(), fail);
1192 }
1193 }
1194
1195 LogTarget(Debug, methodhandles, condy) lt_condy;
1196 if (lt_condy.is_enabled()) {
1197 LogStream ls(lt_condy);
1198 bootstrap_specifier.print_msg_on(&ls, "resolve_constant_at_impl");
1199 }
1200 break;
1201 }
1202
1203 case JVM_CONSTANT_String:
1204 assert(cache_index != _no_index_sentinel, "should have been set");
1205 result_oop = string_at_impl(this_cp, cp_index, cache_index, CHECK_NULL);
1206 break;
1207
1208 case JVM_CONSTANT_MethodHandle:
1209 { PerfTraceTimedEvent timer(ClassLoader::perf_resolve_method_handle_time(),
1210 ClassLoader::perf_resolve_method_handle_count());
1211
1212 int ref_kind = this_cp->method_handle_ref_kind_at(cp_index);
1213 int callee_index = this_cp->method_handle_klass_index_at(cp_index);
1214 Symbol* name = this_cp->method_handle_name_ref_at(cp_index);
1215 Symbol* signature = this_cp->method_handle_signature_ref_at(cp_index);
1216 constantTag m_tag = this_cp->tag_at(this_cp->method_handle_index_at(cp_index));
1217 { ResourceMark rm(THREAD);
1218 log_debug(class, resolve)("resolve JVM_CONSTANT_MethodHandle:%d [%d/%d/%d] %s.%s",
1219 ref_kind, cp_index, this_cp->method_handle_index_at(cp_index),
1220 callee_index, name->as_C_string(), signature->as_C_string());
1221 }
1222
1223 Klass* callee = klass_at_impl(this_cp, callee_index, THREAD);
1224 if (HAS_PENDING_EXCEPTION) {
1225 save_and_throw_exception(this_cp, cp_index, tag, CHECK_NULL);
1226 }
1227
1228 // Check constant pool method consistency
1229 if ((callee->is_interface() && m_tag.is_method()) ||
1230 (!callee->is_interface() && m_tag.is_interface_method())) {
1231 ResourceMark rm(THREAD);
1232 stringStream ss;
1233 ss.print("Inconsistent constant pool data in classfile for class %s. "
1234 "Method '", callee->name()->as_C_string());
1235 signature->print_as_signature_external_return_type(&ss);
1236 ss.print(" %s(", name->as_C_string());
1237 signature->print_as_signature_external_parameters(&ss);
1238 ss.print(")' at index %d is %s and should be %s",
1239 cp_index,
1240 callee->is_interface() ? "CONSTANT_MethodRef" : "CONSTANT_InterfaceMethodRef",
1241 callee->is_interface() ? "CONSTANT_InterfaceMethodRef" : "CONSTANT_MethodRef");
1242 // Names are all known to be < 64k so we know this formatted message is not excessively large.
1243 Exceptions::fthrow(THREAD_AND_LOCATION, vmSymbols::java_lang_IncompatibleClassChangeError(), "%s", ss.as_string());
1244 save_and_throw_exception(this_cp, cp_index, tag, CHECK_NULL);
1245 }
1246
1247 Klass* klass = this_cp->pool_holder();
1248 HandleMark hm(THREAD);
1249 Handle value = SystemDictionary::link_method_handle_constant(klass, ref_kind,
1250 callee, name, signature,
1251 THREAD);
1252 if (HAS_PENDING_EXCEPTION) {
1253 save_and_throw_exception(this_cp, cp_index, tag, CHECK_NULL);
1254 }
1255 result_oop = value();
1256 break;
1257 }
1258
1259 case JVM_CONSTANT_MethodType:
1260 { PerfTraceTimedEvent timer(ClassLoader::perf_resolve_method_type_time(),
1261 ClassLoader::perf_resolve_method_type_count());
1262
1263 Symbol* signature = this_cp->method_type_signature_at(cp_index);
1264 { ResourceMark rm(THREAD);
1265 log_debug(class, resolve)("resolve JVM_CONSTANT_MethodType [%d/%d] %s",
1266 cp_index, this_cp->method_type_index_at(cp_index),
1267 signature->as_C_string());
1268 }
1269 Klass* klass = this_cp->pool_holder();
1270 HandleMark hm(THREAD);
1271 Handle value = SystemDictionary::find_method_handle_type(signature, klass, THREAD);
1272 result_oop = value();
1273 if (HAS_PENDING_EXCEPTION) {
1274 save_and_throw_exception(this_cp, cp_index, tag, CHECK_NULL);
1275 }
1276 break;
1277 }
1278
1279 case JVM_CONSTANT_Integer:
1280 assert(cache_index == _no_index_sentinel, "should not have been set");
1281 prim_value.i = this_cp->int_at(cp_index);
1282 result_oop = java_lang_boxing_object::create(T_INT, &prim_value, CHECK_NULL);
1283 break;
1284
1285 case JVM_CONSTANT_Float:
1286 assert(cache_index == _no_index_sentinel, "should not have been set");
1287 prim_value.f = this_cp->float_at(cp_index);
1288 result_oop = java_lang_boxing_object::create(T_FLOAT, &prim_value, CHECK_NULL);
1289 break;
1290
1291 case JVM_CONSTANT_Long:
1292 assert(cache_index == _no_index_sentinel, "should not have been set");
1293 prim_value.j = this_cp->long_at(cp_index);
1294 result_oop = java_lang_boxing_object::create(T_LONG, &prim_value, CHECK_NULL);
1295 break;
1296
1297 case JVM_CONSTANT_Double:
1298 assert(cache_index == _no_index_sentinel, "should not have been set");
1299 prim_value.d = this_cp->double_at(cp_index);
1300 result_oop = java_lang_boxing_object::create(T_DOUBLE, &prim_value, CHECK_NULL);
1301 break;
1302
1303 case JVM_CONSTANT_UnresolvedClassInError:
1304 case JVM_CONSTANT_DynamicInError:
1305 case JVM_CONSTANT_MethodHandleInError:
1306 case JVM_CONSTANT_MethodTypeInError:
1307 throw_resolution_error(this_cp, cp_index, CHECK_NULL);
1308 break;
1309
1310 default:
1311 fatal("unexpected constant tag at CP %p[%d/%d] = %d", this_cp(), cp_index, cache_index, tag.value());
1312 break;
1313 }
1314
1315 if (cache_index >= 0) {
1316 // Benign race condition: resolved_references may already be filled in.
1317 // The important thing here is that all threads pick up the same result.
1318 // It doesn't matter which racing thread wins, as long as only one
1319 // result is used by all threads, and all future queries.
1320 oop new_result = (result_oop == nullptr ? Universe::the_null_sentinel() : result_oop);
1321 oop old_result = this_cp->set_resolved_reference_at(cache_index, new_result);
1322 if (old_result == nullptr) {
1323 return result_oop; // was installed
1324 } else {
1325 // Return the winning thread's result. This can be different than
1326 // the result here for MethodHandles.
1327 if (old_result == Universe::the_null_sentinel())
1328 old_result = nullptr;
1329 return old_result;
1330 }
1331 } else {
1332 assert(result_oop != Universe::the_null_sentinel(), "");
1333 return result_oop;
1334 }
1335 }
1336
1337 oop ConstantPool::uncached_string_at(int cp_index, TRAPS) {
1338 Symbol* sym = unresolved_string_at(cp_index);
1339 oop str = StringTable::intern(sym, CHECK_(nullptr));
1340 assert(java_lang_String::is_instance(str), "must be string");
1341 return str;
1342 }
1343
1344 void ConstantPool::copy_bootstrap_arguments_at_impl(const constantPoolHandle& this_cp, int cp_index,
1345 int start_arg, int end_arg,
1346 objArrayHandle info, int pos,
1347 bool must_resolve, Handle if_not_available,
1348 TRAPS) {
1349 int limit = pos + end_arg - start_arg;
1350 // checks: cp_index in range [0..this_cp->length),
1351 // tag at cp_index, start..end in range [0..this_cp->bootstrap_argument_count],
1352 // info array non-null, pos..limit in [0..info.length]
1353 if ((0 >= cp_index || cp_index >= this_cp->length()) ||
1354 !(this_cp->tag_at(cp_index).is_invoke_dynamic() ||
1355 this_cp->tag_at(cp_index).is_dynamic_constant()) ||
1356 (0 > start_arg || start_arg > end_arg) ||
1357 (end_arg > this_cp->bootstrap_argument_count_at(cp_index)) ||
1358 (0 > pos || pos > limit) ||
1359 (info.is_null() || limit > info->length())) {
1360 // An index or something else went wrong; throw an error.
1361 // Since this is an internal API, we don't expect this,
1362 // so we don't bother to craft a nice message.
1363 THROW_MSG(vmSymbols::java_lang_LinkageError(), "bad BSM argument access");
1364 }
1365 // now we can loop safely
1366 int info_i = pos;
1367 for (int i = start_arg; i < end_arg; i++) {
1368 int arg_index = this_cp->bootstrap_argument_index_at(cp_index, i);
1369 oop arg_oop;
1370 if (must_resolve) {
1371 arg_oop = this_cp->resolve_possibly_cached_constant_at(arg_index, CHECK);
1372 } else {
1373 bool found_it = false;
1374 arg_oop = this_cp->find_cached_constant_at(arg_index, found_it, CHECK);
1375 if (!found_it) arg_oop = if_not_available();
1376 }
1377 info->obj_at_put(info_i++, arg_oop);
1378 }
1379 }
1380
1381 oop ConstantPool::string_at_impl(const constantPoolHandle& this_cp, int cp_index, int obj_index, TRAPS) {
1382 // If the string has already been interned, this entry will be non-null
1383 oop str = this_cp->resolved_reference_at(obj_index);
1384 assert(str != Universe::the_null_sentinel(), "");
1385 if (str != nullptr) return str;
1386 Symbol* sym = this_cp->unresolved_string_at(cp_index);
1387 str = StringTable::intern(sym, CHECK_(nullptr));
1388 this_cp->string_at_put(obj_index, str);
1389 assert(java_lang_String::is_instance(str), "must be string");
1390 return str;
1391 }
1392
1393
1394 bool ConstantPool::klass_name_at_matches(const InstanceKlass* k, int cp_index) {
1395 // Names are interned, so we can compare Symbol*s directly
1396 Symbol* cp_name = klass_name_at(cp_index);
1397 return (cp_name == k->name());
1398 }
1399
1400
1401 // Iterate over symbols and decrement ones which are Symbol*s
1402 // This is done during GC.
1403 // Only decrement the UTF8 symbols. Strings point to
1404 // these symbols but didn't increment the reference count.
1405 void ConstantPool::unreference_symbols() {
1406 for (int index = 1; index < length(); index++) { // Index 0 is unused
1407 constantTag tag = tag_at(index);
1408 if (tag.is_symbol()) {
1409 symbol_at(index)->decrement_refcount();
1410 }
1411 }
1412 }
1413
1414
1415 // Compare this constant pool's entry at index1 to the constant pool
1416 // cp2's entry at index2.
1417 bool ConstantPool::compare_entry_to(int index1, const constantPoolHandle& cp2,
1418 int index2) {
1419
1420 // The error tags are equivalent to non-error tags when comparing
1421 jbyte t1 = tag_at(index1).non_error_value();
1422 jbyte t2 = cp2->tag_at(index2).non_error_value();
1423
1424 // Some classes are pre-resolved (like Throwable) which may lead to
1425 // consider it as a different entry. We then revert them back temporarily
1426 // to ensure proper comparison.
1427 if (t1 == JVM_CONSTANT_Class) {
1428 t1 = JVM_CONSTANT_UnresolvedClass;
1429 }
1430 if (t2 == JVM_CONSTANT_Class) {
1431 t2 = JVM_CONSTANT_UnresolvedClass;
1432 }
1433
1434 if (t1 != t2) {
1435 // Not the same entry type so there is nothing else to check. Note
1436 // that this style of checking will consider resolved/unresolved
1437 // class pairs as different.
1438 // From the ConstantPool* API point of view, this is correct
1439 // behavior. See VM_RedefineClasses::merge_constant_pools() to see how this
1440 // plays out in the context of ConstantPool* merging.
1441 return false;
1442 }
1443
1444 switch (t1) {
1445 case JVM_CONSTANT_ClassIndex:
1446 {
1447 int recur1 = klass_index_at(index1);
1448 int recur2 = cp2->klass_index_at(index2);
1449 if (compare_entry_to(recur1, cp2, recur2)) {
1450 return true;
1451 }
1452 } break;
1453
1454 case JVM_CONSTANT_Double:
1455 {
1456 jdouble d1 = double_at(index1);
1457 jdouble d2 = cp2->double_at(index2);
1458 if (d1 == d2) {
1459 return true;
1460 }
1461 } break;
1462
1463 case JVM_CONSTANT_Fieldref:
1464 case JVM_CONSTANT_InterfaceMethodref:
1465 case JVM_CONSTANT_Methodref:
1466 {
1467 int recur1 = uncached_klass_ref_index_at(index1);
1468 int recur2 = cp2->uncached_klass_ref_index_at(index2);
1469 bool match = compare_entry_to(recur1, cp2, recur2);
1470 if (match) {
1471 recur1 = uncached_name_and_type_ref_index_at(index1);
1472 recur2 = cp2->uncached_name_and_type_ref_index_at(index2);
1473 if (compare_entry_to(recur1, cp2, recur2)) {
1474 return true;
1475 }
1476 }
1477 } break;
1478
1479 case JVM_CONSTANT_Float:
1480 {
1481 jfloat f1 = float_at(index1);
1482 jfloat f2 = cp2->float_at(index2);
1483 if (f1 == f2) {
1484 return true;
1485 }
1486 } break;
1487
1488 case JVM_CONSTANT_Integer:
1489 {
1490 jint i1 = int_at(index1);
1491 jint i2 = cp2->int_at(index2);
1492 if (i1 == i2) {
1493 return true;
1494 }
1495 } break;
1496
1497 case JVM_CONSTANT_Long:
1498 {
1499 jlong l1 = long_at(index1);
1500 jlong l2 = cp2->long_at(index2);
1501 if (l1 == l2) {
1502 return true;
1503 }
1504 } break;
1505
1506 case JVM_CONSTANT_NameAndType:
1507 {
1508 int recur1 = name_ref_index_at(index1);
1509 int recur2 = cp2->name_ref_index_at(index2);
1510 if (compare_entry_to(recur1, cp2, recur2)) {
1511 recur1 = signature_ref_index_at(index1);
1512 recur2 = cp2->signature_ref_index_at(index2);
1513 if (compare_entry_to(recur1, cp2, recur2)) {
1514 return true;
1515 }
1516 }
1517 } break;
1518
1519 case JVM_CONSTANT_StringIndex:
1520 {
1521 int recur1 = string_index_at(index1);
1522 int recur2 = cp2->string_index_at(index2);
1523 if (compare_entry_to(recur1, cp2, recur2)) {
1524 return true;
1525 }
1526 } break;
1527
1528 case JVM_CONSTANT_UnresolvedClass:
1529 {
1530 Symbol* k1 = klass_name_at(index1);
1531 Symbol* k2 = cp2->klass_name_at(index2);
1532 if (k1 == k2) {
1533 return true;
1534 }
1535 } break;
1536
1537 case JVM_CONSTANT_MethodType:
1538 {
1539 int k1 = method_type_index_at(index1);
1540 int k2 = cp2->method_type_index_at(index2);
1541 if (compare_entry_to(k1, cp2, k2)) {
1542 return true;
1543 }
1544 } break;
1545
1546 case JVM_CONSTANT_MethodHandle:
1547 {
1548 int k1 = method_handle_ref_kind_at(index1);
1549 int k2 = cp2->method_handle_ref_kind_at(index2);
1550 if (k1 == k2) {
1551 int i1 = method_handle_index_at(index1);
1552 int i2 = cp2->method_handle_index_at(index2);
1553 if (compare_entry_to(i1, cp2, i2)) {
1554 return true;
1555 }
1556 }
1557 } break;
1558
1559 case JVM_CONSTANT_Dynamic:
1560 {
1561 int k1 = bootstrap_name_and_type_ref_index_at(index1);
1562 int k2 = cp2->bootstrap_name_and_type_ref_index_at(index2);
1563 int i1 = bootstrap_methods_attribute_index(index1);
1564 int i2 = cp2->bootstrap_methods_attribute_index(index2);
1565 bool match_entry = compare_entry_to(k1, cp2, k2);
1566 bool match_bsm = compare_bootstrap_entry_to(i1, cp2, i2);
1567 return (match_entry && match_bsm);
1568 } break;
1569
1570 case JVM_CONSTANT_InvokeDynamic:
1571 {
1572 int k1 = bootstrap_name_and_type_ref_index_at(index1);
1573 int k2 = cp2->bootstrap_name_and_type_ref_index_at(index2);
1574 int i1 = bootstrap_methods_attribute_index(index1);
1575 int i2 = cp2->bootstrap_methods_attribute_index(index2);
1576 bool match_entry = compare_entry_to(k1, cp2, k2);
1577 bool match_bsm = compare_bootstrap_entry_to(i1, cp2, i2);
1578 return (match_entry && match_bsm);
1579 } break;
1580
1581 case JVM_CONSTANT_String:
1582 {
1583 Symbol* s1 = unresolved_string_at(index1);
1584 Symbol* s2 = cp2->unresolved_string_at(index2);
1585 if (s1 == s2) {
1586 return true;
1587 }
1588 } break;
1589
1590 case JVM_CONSTANT_Utf8:
1591 {
1592 Symbol* s1 = symbol_at(index1);
1593 Symbol* s2 = cp2->symbol_at(index2);
1594 if (s1 == s2) {
1595 return true;
1596 }
1597 } break;
1598
1599 // Invalid is used as the tag for the second constant pool entry
1600 // occupied by JVM_CONSTANT_Double or JVM_CONSTANT_Long. It should
1601 // not be seen by itself.
1602 case JVM_CONSTANT_Invalid: // fall through
1603
1604 default:
1605 ShouldNotReachHere();
1606 break;
1607 }
1608
1609 return false;
1610 } // end compare_entry_to()
1611
1612 // Extend the BSMAttributeEntries with the length and size of the ext_cp BSMAttributeEntries.
1613 // Used in RedefineClasses for CP merge.
1614 BSMAttributeEntries::InsertionIterator
1615 ConstantPool::start_extension(const constantPoolHandle& ext_cp, TRAPS) {
1616 BSMAttributeEntries::InsertionIterator iter =
1617 bsm_entries().start_extension(ext_cp->bsm_entries(), pool_holder()->class_loader_data(),
1618 CHECK_(BSMAttributeEntries::InsertionIterator()));
1619 return iter;
1620 }
1621
1622
1623 void ConstantPool::end_extension(BSMAttributeEntries::InsertionIterator iter, TRAPS) {
1624 bsm_entries().end_extension(iter, pool_holder()->class_loader_data(), THREAD);
1625 }
1626
1627
1628 void ConstantPool::copy_bsm_entries(const constantPoolHandle& from_cp,
1629 const constantPoolHandle& to_cp,
1630 TRAPS) {
1631 to_cp->bsm_entries().append(from_cp->bsm_entries(),
1632 to_cp->pool_holder()->class_loader_data(),
1633 THREAD);
1634 }
1635
1636
1637 // Copy this constant pool's entries at start_i to end_i (inclusive)
1638 // to the constant pool to_cp's entries starting at to_i. A total of
1639 // (end_i - start_i) + 1 entries are copied.
1640 void ConstantPool::copy_cp_to_impl(const constantPoolHandle& from_cp, int start_i, int end_i,
1641 const constantPoolHandle& to_cp, int to_i, TRAPS) {
1642
1643
1644 int dest_cpi = to_i; // leave original alone for debug purposes
1645
1646 for (int src_cpi = start_i; src_cpi <= end_i; /* see loop bottom */ ) {
1647 copy_entry_to(from_cp, src_cpi, to_cp, dest_cpi);
1648
1649 switch (from_cp->tag_at(src_cpi).value()) {
1650 case JVM_CONSTANT_Double:
1651 case JVM_CONSTANT_Long:
1652 // double and long take two constant pool entries
1653 src_cpi += 2;
1654 dest_cpi += 2;
1655 break;
1656
1657 default:
1658 // all others take one constant pool entry
1659 src_cpi++;
1660 dest_cpi++;
1661 break;
1662 }
1663 }
1664 copy_bsm_entries(from_cp, to_cp, THREAD);
1665
1666 } // end copy_cp_to_impl()
1667
1668
1669 // Copy this constant pool's entry at from_i to the constant pool
1670 // to_cp's entry at to_i.
1671 void ConstantPool::copy_entry_to(const constantPoolHandle& from_cp, int from_i,
1672 const constantPoolHandle& to_cp, int to_i) {
1673
1674 int tag = from_cp->tag_at(from_i).value();
1675 switch (tag) {
1676 case JVM_CONSTANT_ClassIndex:
1677 {
1678 jint ki = from_cp->klass_index_at(from_i);
1679 to_cp->klass_index_at_put(to_i, ki);
1680 } break;
1681
1682 case JVM_CONSTANT_Double:
1683 {
1684 jdouble d = from_cp->double_at(from_i);
1685 to_cp->double_at_put(to_i, d);
1686 // double takes two constant pool entries so init second entry's tag
1687 to_cp->tag_at_put(to_i + 1, JVM_CONSTANT_Invalid);
1688 } break;
1689
1690 case JVM_CONSTANT_Fieldref:
1691 {
1692 int class_index = from_cp->uncached_klass_ref_index_at(from_i);
1693 int name_and_type_index = from_cp->uncached_name_and_type_ref_index_at(from_i);
1694 to_cp->field_at_put(to_i, class_index, name_and_type_index);
1695 } break;
1696
1697 case JVM_CONSTANT_Float:
1698 {
1699 jfloat f = from_cp->float_at(from_i);
1700 to_cp->float_at_put(to_i, f);
1701 } break;
1702
1703 case JVM_CONSTANT_Integer:
1704 {
1705 jint i = from_cp->int_at(from_i);
1706 to_cp->int_at_put(to_i, i);
1707 } break;
1708
1709 case JVM_CONSTANT_InterfaceMethodref:
1710 {
1711 int class_index = from_cp->uncached_klass_ref_index_at(from_i);
1712 int name_and_type_index = from_cp->uncached_name_and_type_ref_index_at(from_i);
1713 to_cp->interface_method_at_put(to_i, class_index, name_and_type_index);
1714 } break;
1715
1716 case JVM_CONSTANT_Long:
1717 {
1718 jlong l = from_cp->long_at(from_i);
1719 to_cp->long_at_put(to_i, l);
1720 // long takes two constant pool entries so init second entry's tag
1721 to_cp->tag_at_put(to_i + 1, JVM_CONSTANT_Invalid);
1722 } break;
1723
1724 case JVM_CONSTANT_Methodref:
1725 {
1726 int class_index = from_cp->uncached_klass_ref_index_at(from_i);
1727 int name_and_type_index = from_cp->uncached_name_and_type_ref_index_at(from_i);
1728 to_cp->method_at_put(to_i, class_index, name_and_type_index);
1729 } break;
1730
1731 case JVM_CONSTANT_NameAndType:
1732 {
1733 int name_ref_index = from_cp->name_ref_index_at(from_i);
1734 int signature_ref_index = from_cp->signature_ref_index_at(from_i);
1735 to_cp->name_and_type_at_put(to_i, name_ref_index, signature_ref_index);
1736 } break;
1737
1738 case JVM_CONSTANT_StringIndex:
1739 {
1740 jint si = from_cp->string_index_at(from_i);
1741 to_cp->string_index_at_put(to_i, si);
1742 } break;
1743
1744 case JVM_CONSTANT_Class:
1745 case JVM_CONSTANT_UnresolvedClass:
1746 case JVM_CONSTANT_UnresolvedClassInError:
1747 {
1748 // Revert to JVM_CONSTANT_ClassIndex
1749 int name_index = from_cp->klass_slot_at(from_i).name_index();
1750 assert(from_cp->tag_at(name_index).is_symbol(), "sanity");
1751 to_cp->klass_index_at_put(to_i, name_index);
1752 } break;
1753
1754 case JVM_CONSTANT_String:
1755 {
1756 Symbol* s = from_cp->unresolved_string_at(from_i);
1757 to_cp->unresolved_string_at_put(to_i, s);
1758 } break;
1759
1760 case JVM_CONSTANT_Utf8:
1761 {
1762 Symbol* s = from_cp->symbol_at(from_i);
1763 // Need to increase refcount, the old one will be thrown away and deferenced
1764 s->increment_refcount();
1765 to_cp->symbol_at_put(to_i, s);
1766 } break;
1767
1768 case JVM_CONSTANT_MethodType:
1769 case JVM_CONSTANT_MethodTypeInError:
1770 {
1771 jint k = from_cp->method_type_index_at(from_i);
1772 to_cp->method_type_index_at_put(to_i, k);
1773 } break;
1774
1775 case JVM_CONSTANT_MethodHandle:
1776 case JVM_CONSTANT_MethodHandleInError:
1777 {
1778 int k1 = from_cp->method_handle_ref_kind_at(from_i);
1779 int k2 = from_cp->method_handle_index_at(from_i);
1780 to_cp->method_handle_index_at_put(to_i, k1, k2);
1781 } break;
1782
1783 case JVM_CONSTANT_Dynamic:
1784 case JVM_CONSTANT_DynamicInError:
1785 {
1786 int k1 = from_cp->bootstrap_methods_attribute_index(from_i);
1787 int k2 = from_cp->bootstrap_name_and_type_ref_index_at(from_i);
1788 k1 += to_cp->bsm_entries().array_length(); // to_cp might already have a BSM attribute
1789 to_cp->dynamic_constant_at_put(to_i, k1, k2);
1790 } break;
1791
1792 case JVM_CONSTANT_InvokeDynamic:
1793 {
1794 int k1 = from_cp->bootstrap_methods_attribute_index(from_i);
1795 int k2 = from_cp->bootstrap_name_and_type_ref_index_at(from_i);
1796 k1 += to_cp->bsm_entries().array_length(); // to_cp might already have a BSM attribute
1797 to_cp->invoke_dynamic_at_put(to_i, k1, k2);
1798 } break;
1799
1800 // Invalid is used as the tag for the second constant pool entry
1801 // occupied by JVM_CONSTANT_Double or JVM_CONSTANT_Long. It should
1802 // not be seen by itself.
1803 case JVM_CONSTANT_Invalid: // fall through
1804
1805 default:
1806 {
1807 ShouldNotReachHere();
1808 } break;
1809 }
1810 } // end copy_entry_to()
1811
1812 // Search constant pool search_cp for an entry that matches this
1813 // constant pool's entry at pattern_i. Returns the index of a
1814 // matching entry or zero (0) if there is no matching entry.
1815 int ConstantPool::find_matching_entry(int pattern_i,
1816 const constantPoolHandle& search_cp) {
1817
1818 // index zero (0) is not used
1819 for (int i = 1; i < search_cp->length(); i++) {
1820 bool found = compare_entry_to(pattern_i, search_cp, i);
1821 if (found) {
1822 return i;
1823 }
1824 }
1825
1826 return 0; // entry not found; return unused index zero (0)
1827 } // end find_matching_entry()
1828
1829
1830 // Compare this constant pool's bootstrap specifier at idx1 to the constant pool
1831 // cp2's bootstrap specifier at idx2.
1832 bool ConstantPool::compare_bootstrap_entry_to(int idx1, const constantPoolHandle& cp2, int idx2) {
1833 const BSMAttributeEntry* const e1 = bsm_attribute_entry(idx1);
1834 const BSMAttributeEntry* const e2 = cp2->bsm_attribute_entry(idx2);
1835 int k1 = e1->bootstrap_method_index();
1836 int k2 = e2->bootstrap_method_index();
1837 bool match = compare_entry_to(k1, cp2, k2);
1838
1839 if (!match) {
1840 return false;
1841 }
1842
1843 const int argc = e1->argument_count();
1844 if (argc != e2->argument_count()) {
1845 return false;
1846 }
1847
1848 for (int j = 0; j < argc; j++) {
1849 k1 = e1->argument(j);
1850 k2 = e2->argument(j);
1851 match = compare_entry_to(k1, cp2, k2);
1852 if (!match) {
1853 return false;
1854 }
1855 }
1856
1857 return true; // got through loop; all elements equal
1858 } // end compare_bootstrap_entry_to()
1859
1860 // Search constant pool search_cp for a bootstrap specifier that matches
1861 // this constant pool's bootstrap specifier data at pattern_i index.
1862 // Return the index of a matching bootstrap attribute record or (-1) if there is no match.
1863 int ConstantPool::find_matching_bsm_entry(int pattern_i,
1864 const constantPoolHandle& search_cp, int offset_limit) {
1865 for (int i = 0; i < offset_limit; i++) {
1866 bool found = compare_bootstrap_entry_to(pattern_i, search_cp, i);
1867 if (found) {
1868 return i;
1869 }
1870 }
1871 return -1; // bootstrap specifier data not found; return unused index (-1)
1872 } // end find_matching_bsm_entry()
1873
1874
1875 #ifndef PRODUCT
1876
1877 const char* ConstantPool::printable_name_at(int cp_index) {
1878
1879 constantTag tag = tag_at(cp_index);
1880
1881 if (tag.is_string()) {
1882 return string_at_noresolve(cp_index);
1883 } else if (tag.is_klass() || tag.is_unresolved_klass()) {
1884 return klass_name_at(cp_index)->as_C_string();
1885 } else if (tag.is_symbol()) {
1886 return symbol_at(cp_index)->as_C_string();
1887 }
1888 return "";
1889 }
1890
1891 #endif // PRODUCT
1892
1893
1894 // Returns size of constant pool entry.
1895 jint ConstantPool::cpool_entry_size(jint idx) {
1896 switch(tag_at(idx).value()) {
1897 case JVM_CONSTANT_Invalid:
1898 case JVM_CONSTANT_Unicode:
1899 return 1;
1900
1901 case JVM_CONSTANT_Utf8:
1902 return 3 + symbol_at(idx)->utf8_length();
1903
1904 case JVM_CONSTANT_Class:
1905 case JVM_CONSTANT_String:
1906 case JVM_CONSTANT_ClassIndex:
1907 case JVM_CONSTANT_UnresolvedClass:
1908 case JVM_CONSTANT_UnresolvedClassInError:
1909 case JVM_CONSTANT_StringIndex:
1910 case JVM_CONSTANT_MethodType:
1911 case JVM_CONSTANT_MethodTypeInError:
1912 return 3;
1913
1914 case JVM_CONSTANT_MethodHandle:
1915 case JVM_CONSTANT_MethodHandleInError:
1916 return 4; //tag, ref_kind, ref_index
1917
1918 case JVM_CONSTANT_Integer:
1919 case JVM_CONSTANT_Float:
1920 case JVM_CONSTANT_Fieldref:
1921 case JVM_CONSTANT_Methodref:
1922 case JVM_CONSTANT_InterfaceMethodref:
1923 case JVM_CONSTANT_NameAndType:
1924 return 5;
1925
1926 case JVM_CONSTANT_Dynamic:
1927 case JVM_CONSTANT_DynamicInError:
1928 case JVM_CONSTANT_InvokeDynamic:
1929 // u1 tag, u2 bsm, u2 nt
1930 return 5;
1931
1932 case JVM_CONSTANT_Long:
1933 case JVM_CONSTANT_Double:
1934 return 9;
1935 }
1936 assert(false, "cpool_entry_size: Invalid constant pool entry tag");
1937 return 1;
1938 } /* end cpool_entry_size */
1939
1940
1941 // SymbolHash is used to find a constant pool index from a string.
1942 // This function fills in SymbolHashs, one for utf8s and one for
1943 // class names, returns size of the cpool raw bytes.
1944 jint ConstantPool::hash_entries_to(SymbolHash *symmap,
1945 SymbolHash *classmap) {
1946 jint size = 0;
1947
1948 for (u2 idx = 1; idx < length(); idx++) {
1949 u2 tag = tag_at(idx).value();
1950 size += cpool_entry_size(idx);
1951
1952 switch(tag) {
1953 case JVM_CONSTANT_Utf8: {
1954 Symbol* sym = symbol_at(idx);
1955 symmap->add_if_absent(sym, idx);
1956 break;
1957 }
1958 case JVM_CONSTANT_Class:
1959 case JVM_CONSTANT_UnresolvedClass:
1960 case JVM_CONSTANT_UnresolvedClassInError: {
1961 Symbol* sym = klass_name_at(idx);
1962 classmap->add_if_absent(sym, idx);
1963 break;
1964 }
1965 case JVM_CONSTANT_Long:
1966 case JVM_CONSTANT_Double: {
1967 idx++; // Both Long and Double take two cpool slots
1968 break;
1969 }
1970 }
1971 }
1972 return size;
1973 } /* end hash_utf8_entries_to */
1974
1975
1976 // Copy cpool bytes.
1977 // Returns:
1978 // 0, in case of OutOfMemoryError
1979 // -1, in case of internal error
1980 // > 0, count of the raw cpool bytes that have been copied
1981 int ConstantPool::copy_cpool_bytes(int cpool_size,
1982 SymbolHash* tbl,
1983 unsigned char *bytes) {
1984 u2 idx1, idx2;
1985 jint size = 0;
1986 jint cnt = length();
1987 unsigned char *start_bytes = bytes;
1988
1989 for (jint idx = 1; idx < cnt; idx++) {
1990 u1 tag = tag_at(idx).value();
1991 jint ent_size = cpool_entry_size(idx);
1992
1993 assert(size + ent_size <= cpool_size, "Size mismatch");
1994
1995 *bytes = tag;
1996 switch(tag) {
1997 case JVM_CONSTANT_Invalid: {
1998 break;
1999 }
2000 case JVM_CONSTANT_Unicode: {
2001 assert(false, "Wrong constant pool tag: JVM_CONSTANT_Unicode");
2002 break;
2003 }
2004 case JVM_CONSTANT_Utf8: {
2005 Symbol* sym = symbol_at(idx);
2006 char* str = sym->as_utf8();
2007 // Warning! It's crashing on x86 with len = sym->utf8_length()
2008 int len = (int) strlen(str);
2009 Bytes::put_Java_u2((address) (bytes+1), (u2) len);
2010 for (int i = 0; i < len; i++) {
2011 bytes[3+i] = (u1) str[i];
2012 }
2013 break;
2014 }
2015 case JVM_CONSTANT_Integer: {
2016 jint val = int_at(idx);
2017 Bytes::put_Java_u4((address) (bytes+1), *(u4*)&val);
2018 break;
2019 }
2020 case JVM_CONSTANT_Float: {
2021 jfloat val = float_at(idx);
2022 Bytes::put_Java_u4((address) (bytes+1), *(u4*)&val);
2023 break;
2024 }
2025 case JVM_CONSTANT_Long: {
2026 jlong val = long_at(idx);
2027 Bytes::put_Java_u8((address) (bytes+1), *(u8*)&val);
2028 idx++; // Long takes two cpool slots
2029 break;
2030 }
2031 case JVM_CONSTANT_Double: {
2032 jdouble val = double_at(idx);
2033 Bytes::put_Java_u8((address) (bytes+1), *(u8*)&val);
2034 idx++; // Double takes two cpool slots
2035 break;
2036 }
2037 case JVM_CONSTANT_Class:
2038 case JVM_CONSTANT_UnresolvedClass:
2039 case JVM_CONSTANT_UnresolvedClassInError: {
2040 *bytes = JVM_CONSTANT_Class;
2041 Symbol* sym = klass_name_at(idx);
2042 idx1 = tbl->symbol_to_value(sym);
2043 assert(idx1 != 0, "Have not found a hashtable entry");
2044 Bytes::put_Java_u2((address) (bytes+1), idx1);
2045 break;
2046 }
2047 case JVM_CONSTANT_String: {
2048 *bytes = JVM_CONSTANT_String;
2049 Symbol* sym = unresolved_string_at(idx);
2050 idx1 = tbl->symbol_to_value(sym);
2051 assert(idx1 != 0, "Have not found a hashtable entry");
2052 Bytes::put_Java_u2((address) (bytes+1), idx1);
2053 break;
2054 }
2055 case JVM_CONSTANT_Fieldref:
2056 case JVM_CONSTANT_Methodref:
2057 case JVM_CONSTANT_InterfaceMethodref: {
2058 idx1 = uncached_klass_ref_index_at(idx);
2059 idx2 = uncached_name_and_type_ref_index_at(idx);
2060 Bytes::put_Java_u2((address) (bytes+1), idx1);
2061 Bytes::put_Java_u2((address) (bytes+3), idx2);
2062 break;
2063 }
2064 case JVM_CONSTANT_NameAndType: {
2065 idx1 = name_ref_index_at(idx);
2066 idx2 = signature_ref_index_at(idx);
2067 Bytes::put_Java_u2((address) (bytes+1), idx1);
2068 Bytes::put_Java_u2((address) (bytes+3), idx2);
2069 break;
2070 }
2071 case JVM_CONSTANT_ClassIndex: {
2072 *bytes = JVM_CONSTANT_Class;
2073 idx1 = checked_cast<u2>(klass_index_at(idx));
2074 Bytes::put_Java_u2((address) (bytes+1), idx1);
2075 break;
2076 }
2077 case JVM_CONSTANT_StringIndex: {
2078 *bytes = JVM_CONSTANT_String;
2079 idx1 = checked_cast<u2>(string_index_at(idx));
2080 Bytes::put_Java_u2((address) (bytes+1), idx1);
2081 break;
2082 }
2083 case JVM_CONSTANT_MethodHandle:
2084 case JVM_CONSTANT_MethodHandleInError: {
2085 *bytes = JVM_CONSTANT_MethodHandle;
2086 int kind = method_handle_ref_kind_at(idx);
2087 idx1 = checked_cast<u2>(method_handle_index_at(idx));
2088 *(bytes+1) = (unsigned char) kind;
2089 Bytes::put_Java_u2((address) (bytes+2), idx1);
2090 break;
2091 }
2092 case JVM_CONSTANT_MethodType:
2093 case JVM_CONSTANT_MethodTypeInError: {
2094 *bytes = JVM_CONSTANT_MethodType;
2095 idx1 = checked_cast<u2>(method_type_index_at(idx));
2096 Bytes::put_Java_u2((address) (bytes+1), idx1);
2097 break;
2098 }
2099 case JVM_CONSTANT_Dynamic:
2100 case JVM_CONSTANT_DynamicInError: {
2101 *bytes = tag;
2102 idx1 = extract_low_short_from_int(*int_at_addr(idx));
2103 idx2 = extract_high_short_from_int(*int_at_addr(idx));
2104 assert(idx2 == bootstrap_name_and_type_ref_index_at(idx), "correct half of u4");
2105 Bytes::put_Java_u2((address) (bytes+1), idx1);
2106 Bytes::put_Java_u2((address) (bytes+3), idx2);
2107 break;
2108 }
2109 case JVM_CONSTANT_InvokeDynamic: {
2110 *bytes = tag;
2111 idx1 = extract_low_short_from_int(*int_at_addr(idx));
2112 idx2 = extract_high_short_from_int(*int_at_addr(idx));
2113 assert(idx2 == bootstrap_name_and_type_ref_index_at(idx), "correct half of u4");
2114 Bytes::put_Java_u2((address) (bytes+1), idx1);
2115 Bytes::put_Java_u2((address) (bytes+3), idx2);
2116 break;
2117 }
2118 }
2119 bytes += ent_size;
2120 size += ent_size;
2121 }
2122 assert(size == cpool_size, "Size mismatch");
2123
2124 return (int)(bytes - start_bytes);
2125 } /* end copy_cpool_bytes */
2126
2127 bool ConstantPool::is_maybe_on_stack() const {
2128 // This method uses the similar logic as nmethod::is_maybe_on_stack()
2129 if (!Continuations::enabled()) {
2130 return false;
2131 }
2132
2133 // If the condition below is true, it means that the nmethod was found to
2134 // be alive the previous completed marking cycle.
2135 return cache()->gc_epoch() >= CodeCache::previous_completed_gc_marking_cycle();
2136 }
2137
2138 // For redefinition, if any methods found in loom stack chunks, the gc_epoch is
2139 // recorded in their constant pool cache. The on_stack-ness of the constant pool controls whether
2140 // memory for the method is reclaimed.
2141 bool ConstantPool::on_stack() const {
2142 if ((_flags &_on_stack) != 0) {
2143 return true;
2144 }
2145
2146 if (_cache == nullptr) {
2147 return false;
2148 }
2149
2150 return is_maybe_on_stack();
2151 }
2152
2153 void ConstantPool::set_on_stack(const bool value) {
2154 if (value) {
2155 // Only record if it's not already set.
2156 if (!on_stack()) {
2157 assert(!in_aot_cache(), "should always be set for constant pools in AOT cache");
2158 _flags |= _on_stack;
2159 MetadataOnStackMark::record(this);
2160 }
2161 } else {
2162 // Clearing is done single-threadedly.
2163 if (!in_aot_cache()) {
2164 _flags &= (u2)(~_on_stack);
2165 }
2166 }
2167 }
2168
2169 // Printing
2170
2171 void ConstantPool::print_on(outputStream* st) const {
2172 assert(is_constantPool(), "must be constantPool");
2173 st->print_cr("%s", internal_name());
2174 if (flags() != 0) {
2175 st->print(" - flags: 0x%x", flags());
2176 if (has_preresolution()) st->print(" has_preresolution");
2177 if (on_stack()) st->print(" on_stack");
2178 st->cr();
2179 }
2180 if (pool_holder() != nullptr) {
2181 st->print_cr(" - holder: " PTR_FORMAT, p2i(pool_holder()));
2182 }
2183 st->print_cr(" - cache: " PTR_FORMAT, p2i(cache()));
2184 st->print_cr(" - resolved_references: " PTR_FORMAT, p2i(resolved_references_or_null()));
2185 st->print_cr(" - reference_map: " PTR_FORMAT, p2i(reference_map()));
2186 st->print_cr(" - resolved_klasses: " PTR_FORMAT, p2i(resolved_klasses()));
2187 st->print_cr(" - cp length: %d", length());
2188
2189 for (int index = 1; index < length(); index++) { // Index 0 is unused
2190 ((ConstantPool*)this)->print_entry_on(index, st);
2191 switch (tag_at(index).value()) {
2192 case JVM_CONSTANT_Long :
2193 case JVM_CONSTANT_Double :
2194 index++; // Skip entry following eigth-byte constant
2195 }
2196
2197 }
2198 st->cr();
2199 }
2200
2201 // Print one constant pool entry
2202 void ConstantPool::print_entry_on(const int cp_index, outputStream* st) {
2203 EXCEPTION_MARK;
2204 st->print(" - %3d : ", cp_index);
2205 tag_at(cp_index).print_on(st);
2206 st->print(" : ");
2207 switch (tag_at(cp_index).value()) {
2208 case JVM_CONSTANT_Class :
2209 { Klass* k = klass_at(cp_index, CATCH);
2210 guarantee(k != nullptr, "need klass");
2211 k->print_value_on(st);
2212 st->print(" {" PTR_FORMAT "}", p2i(k));
2213 }
2214 break;
2215 case JVM_CONSTANT_Fieldref :
2216 case JVM_CONSTANT_Methodref :
2217 case JVM_CONSTANT_InterfaceMethodref :
2218 st->print("klass_index=%d", uncached_klass_ref_index_at(cp_index));
2219 st->print(" name_and_type_index=%d", uncached_name_and_type_ref_index_at(cp_index));
2220 break;
2221 case JVM_CONSTANT_String :
2222 unresolved_string_at(cp_index)->print_value_on(st);
2223 break;
2224 case JVM_CONSTANT_Integer :
2225 st->print("%d", int_at(cp_index));
2226 break;
2227 case JVM_CONSTANT_Float :
2228 st->print("%f", float_at(cp_index));
2229 break;
2230 case JVM_CONSTANT_Long :
2231 st->print_jlong(long_at(cp_index));
2232 break;
2233 case JVM_CONSTANT_Double :
2234 st->print("%lf", double_at(cp_index));
2235 break;
2236 case JVM_CONSTANT_NameAndType :
2237 st->print("name_index=%d", name_ref_index_at(cp_index));
2238 st->print(" signature_index=%d", signature_ref_index_at(cp_index));
2239 break;
2240 case JVM_CONSTANT_Utf8 :
2241 symbol_at(cp_index)->print_value_on(st);
2242 break;
2243 case JVM_CONSTANT_ClassIndex: {
2244 int name_index = *int_at_addr(cp_index);
2245 st->print("klass_index=%d ", name_index);
2246 symbol_at(name_index)->print_value_on(st);
2247 }
2248 break;
2249 case JVM_CONSTANT_UnresolvedClass : // fall-through
2250 case JVM_CONSTANT_UnresolvedClassInError: {
2251 CPKlassSlot kslot = klass_slot_at(cp_index);
2252 int resolved_klass_index = kslot.resolved_klass_index();
2253 int name_index = kslot.name_index();
2254 assert(tag_at(name_index).is_symbol(), "sanity");
2255 symbol_at(name_index)->print_value_on(st);
2256 }
2257 break;
2258 case JVM_CONSTANT_MethodHandle :
2259 case JVM_CONSTANT_MethodHandleInError :
2260 st->print("ref_kind=%d", method_handle_ref_kind_at(cp_index));
2261 st->print(" ref_index=%d", method_handle_index_at(cp_index));
2262 break;
2263 case JVM_CONSTANT_MethodType :
2264 case JVM_CONSTANT_MethodTypeInError :
2265 st->print("signature_index=%d", method_type_index_at(cp_index));
2266 break;
2267 case JVM_CONSTANT_Dynamic :
2268 case JVM_CONSTANT_DynamicInError :
2269 {
2270 st->print("bootstrap_method_index=%d", bootstrap_method_ref_index_at(cp_index));
2271 st->print(" type_index=%d", bootstrap_name_and_type_ref_index_at(cp_index));
2272 int argc = bootstrap_argument_count_at(cp_index);
2273 if (argc > 0) {
2274 for (int arg_i = 0; arg_i < argc; arg_i++) {
2275 int arg = bootstrap_argument_index_at(cp_index, arg_i);
2276 st->print((arg_i == 0 ? " arguments={%d" : ", %d"), arg);
2277 }
2278 st->print("}");
2279 }
2280 }
2281 break;
2282 case JVM_CONSTANT_InvokeDynamic :
2283 {
2284 st->print("bootstrap_method_index=%d", bootstrap_method_ref_index_at(cp_index));
2285 st->print(" name_and_type_index=%d", bootstrap_name_and_type_ref_index_at(cp_index));
2286 int argc = bootstrap_argument_count_at(cp_index);
2287 if (argc > 0) {
2288 for (int arg_i = 0; arg_i < argc; arg_i++) {
2289 int arg = bootstrap_argument_index_at(cp_index, arg_i);
2290 st->print((arg_i == 0 ? " arguments={%d" : ", %d"), arg);
2291 }
2292 st->print("}");
2293 }
2294 }
2295 break;
2296 default:
2297 ShouldNotReachHere();
2298 break;
2299 }
2300 st->cr();
2301 }
2302
2303 void ConstantPool::print_value_on(outputStream* st) const {
2304 assert(is_constantPool(), "must be constantPool");
2305 st->print("constant pool [%d]", length());
2306 if (has_preresolution()) st->print("/preresolution");
2307 if (!bsm_entries().is_empty()) st->print("/BSMs[%d]", bsm_entries().bootstrap_methods()->length());
2308 print_address_on(st);
2309 if (pool_holder() != nullptr) {
2310 st->print(" for ");
2311 pool_holder()->print_value_on(st);
2312 bool extra = (pool_holder()->constants() != this);
2313 if (extra) st->print(" (extra)");
2314 }
2315 if (cache() != nullptr) {
2316 st->print(" cache=" PTR_FORMAT, p2i(cache()));
2317 }
2318 }
2319
2320 // Verification
2321
2322 void ConstantPool::verify_on(outputStream* st) {
2323 guarantee(is_constantPool(), "object must be constant pool");
2324 for (int i = 0; i< length(); i++) {
2325 constantTag tag = tag_at(i);
2326 if (tag.is_klass() || tag.is_unresolved_klass()) {
2327 guarantee(klass_name_at(i)->refcount() != 0, "should have nonzero reference count");
2328 } else if (tag.is_symbol()) {
2329 Symbol* entry = symbol_at(i);
2330 guarantee(entry->refcount() != 0, "should have nonzero reference count");
2331 } else if (tag.is_string()) {
2332 Symbol* entry = unresolved_string_at(i);
2333 guarantee(entry->refcount() != 0, "should have nonzero reference count");
2334 }
2335 }
2336 if (pool_holder() != nullptr) {
2337 // Note: pool_holder() can be null in temporary constant pools
2338 // used during constant pool merging
2339 guarantee(pool_holder()->is_klass(), "should be klass");
2340 }
2341 }
2342
2343 void BSMAttributeEntries::deallocate_contents(ClassLoaderData* loader_data) {
2344 MetadataFactory::free_array<u4>(loader_data, this->_offsets);
2345 MetadataFactory::free_array<u2>(loader_data, this->_bootstrap_methods);
2346 this->_offsets = nullptr;
2347 this->_bootstrap_methods = nullptr;
2348 }
2349
2350 void BSMAttributeEntries::copy_into(InsertionIterator& iter, int num_entries) const {
2351 assert(num_entries + iter._cur_offset <= iter._insert_into->_offsets->length(), "must");
2352 for (int i = 0; i < num_entries; i++) {
2353 const BSMAttributeEntry* e = entry(i);
2354 BSMAttributeEntry* e_new = iter.reserve_new_entry(e->bootstrap_method_index(), e->argument_count());
2355 assert(e_new != nullptr, "must be");
2356 e->copy_args_into(e_new);
2357 }
2358 }
2359
2360 BSMAttributeEntries::InsertionIterator
2361 BSMAttributeEntries::start_extension(const BSMAttributeEntries& other, ClassLoaderData* loader_data, TRAPS) {
2362 InsertionIterator iter = start_extension(other.number_of_entries(), other.array_length(),
2363 loader_data, CHECK_(BSMAttributeEntries::InsertionIterator()));
2364 return iter;
2365 }
2366
2367 BSMAttributeEntries::InsertionIterator
2368 BSMAttributeEntries::start_extension(int number_of_entries, int array_length,
2369 ClassLoaderData* loader_data, TRAPS) {
2370 InsertionIterator extension_iterator(this, this->number_of_entries(), this->array_length());
2371 int new_number_of_entries = this->number_of_entries() + number_of_entries;
2372 int new_array_length = this->array_length() + array_length;
2373 int invalid_index = new_array_length;
2374
2375 Array<u4>* new_offsets =
2376 MetadataFactory::new_array<u4>(loader_data, new_number_of_entries, invalid_index, CHECK_(InsertionIterator()));
2377 Array<u2>* new_array = MetadataFactory::new_array<u2>(loader_data, new_array_length, CHECK_(InsertionIterator()));
2378 { // Copy over all the old BSMAEntry's and their respective offsets
2379 BSMAttributeEntries carrier(new_offsets, new_array);
2380 InsertionIterator copy_iter(&carrier, 0, 0);
2381 copy_into(copy_iter, this->number_of_entries());
2382 }
2383 // Replace content
2384 deallocate_contents(loader_data);
2385 _offsets = new_offsets;
2386 _bootstrap_methods = new_array;
2387 return extension_iterator;
2388 }
2389
2390
2391 void BSMAttributeEntries::append(const BSMAttributeEntries& other, ClassLoaderData* loader_data, TRAPS) {
2392 if (other.number_of_entries() == 0) {
2393 return; // Done!
2394 }
2395 InsertionIterator iter = start_extension(other, loader_data, CHECK);
2396 other.copy_into(iter, other.number_of_entries());
2397 end_extension(iter, loader_data, THREAD);
2398 }
2399
2400 void BSMAttributeEntries::end_extension(InsertionIterator& iter, ClassLoaderData* loader_data, TRAPS) {
2401 assert(iter._insert_into == this, "must be");
2402 assert(iter._cur_offset <= this->_offsets->length(), "must be");
2403 assert(iter._cur_array <= this->_bootstrap_methods->length(), "must be");
2404
2405 // Did we fill up all of the available space? If so, do nothing.
2406 if (iter._cur_offset == this->_offsets->length() &&
2407 iter._cur_array == this->_bootstrap_methods->length()) {
2408 return;
2409 }
2410
2411 // We used less, truncate by allocating new arrays
2412 Array<u4>* new_offsets =
2413 MetadataFactory::new_array<u4>(loader_data, iter._cur_offset, 0, CHECK);
2414 Array<u2>* new_array =
2415 MetadataFactory::new_array<u2>(loader_data, iter._cur_array, CHECK);
2416 { // Copy over the constructed BSMAEntry's
2417 BSMAttributeEntries carrier(new_offsets, new_array);
2418 InsertionIterator copy_iter(&carrier, 0, 0);
2419 copy_into(copy_iter, iter._cur_offset);
2420 }
2421
2422 deallocate_contents(loader_data);
2423 _offsets = new_offsets;
2424 _bootstrap_methods = new_array;
2425 }