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