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/bsmAttribute.inline.hpp"
52 #include "oops/constantPool.inline.hpp"
53 #include "oops/cpCache.inline.hpp"
54 #include "oops/fieldStreams.inline.hpp"
55 #include "oops/instanceKlass.hpp"
56 #include "oops/klass.inline.hpp"
57 #include "oops/objArrayKlass.hpp"
58 #include "oops/objArrayOop.inline.hpp"
59 #include "oops/oop.inline.hpp"
60 #include "oops/typeArrayOop.inline.hpp"
61 #include "prims/jvmtiExport.hpp"
62 #include "runtime/atomicAccess.hpp"
63 #include "runtime/fieldDescriptor.inline.hpp"
64 #include "runtime/handles.inline.hpp"
65 #include "runtime/init.hpp"
66 #include "runtime/javaCalls.hpp"
67 #include "runtime/javaThread.inline.hpp"
68 #include "runtime/perfData.hpp"
69 #include "runtime/signature.hpp"
70 #include "runtime/vframe.inline.hpp"
71 #include "utilities/checkedCast.hpp"
72 #include "utilities/copy.hpp"
73
74 ConstantPool* ConstantPool::allocate(ClassLoaderData* loader_data, int length, TRAPS) {
75 Array<u1>* tags = MetadataFactory::new_array<u1>(loader_data, length, 0, CHECK_NULL);
76 int size = ConstantPool::size(length);
77 return new (loader_data, size, MetaspaceObj::ConstantPoolType, THREAD) ConstantPool(tags);
78 }
79
80 void ConstantPool::copy_fields(const ConstantPool* orig) {
81 // Preserve dynamic constant information from the original pool
82 if (orig->has_dynamic_constant()) {
83 set_has_dynamic_constant();
84 }
85
86 set_major_version(orig->major_version());
87 set_minor_version(orig->minor_version());
88
89 set_source_file_name_index(orig->source_file_name_index());
90 set_generic_signature_index(orig->generic_signature_index());
91 }
92
93 #ifdef ASSERT
94
95 // MetaspaceObj allocation invariant is calloc equivalent memory
96 // simple verification of this here (JVM_CONSTANT_Invalid == 0 )
97 static bool tag_array_is_zero_initialized(Array<u1>* tags) {
98 assert(tags != nullptr, "invariant");
99 const int length = tags->length();
100 for (int index = 0; index < length; ++index) {
101 if (JVM_CONSTANT_Invalid != tags->at(index)) {
102 return false;
103 }
104 }
105 return true;
106 }
107
108 #endif
109
110 ConstantPool::ConstantPool() {
111 assert(CDSConfig::is_dumping_static_archive() || CDSConfig::is_using_archive(), "only for CDS");
112 }
113
114 ConstantPool::ConstantPool(Array<u1>* tags) :
115 _tags(tags),
116 _length(tags->length()) {
117
118 assert(_tags != nullptr, "invariant");
119 assert(tags->length() == _length, "invariant");
120 assert(tag_array_is_zero_initialized(tags), "invariant");
121 assert(0 == flags(), "invariant");
122 assert(0 == version(), "invariant");
123 assert(nullptr == _pool_holder, "invariant");
124 }
125
126 void ConstantPool::deallocate_contents(ClassLoaderData* loader_data) {
127 if (cache() != nullptr) {
128 MetadataFactory::free_metadata(loader_data, cache());
129 set_cache(nullptr);
130 }
131
132 MetadataFactory::free_array<Klass*>(loader_data, resolved_klasses());
133 set_resolved_klasses(nullptr);
134
135 bsm_entries().deallocate_contents(loader_data);
136
137 release_C_heap_structures();
138
139 // free tag array
140 MetadataFactory::free_array<u1>(loader_data, tags());
141 set_tags(nullptr);
142 }
143
144 void ConstantPool::release_C_heap_structures() {
145 // walk constant pool and decrement symbol reference counts
146 unreference_symbols();
147 }
148
149 void ConstantPool::metaspace_pointers_do(MetaspaceClosure* it) {
150 log_trace(aot)("Iter(ConstantPool): %p", this);
151
152 it->push(&_tags, MetaspaceClosure::_writable);
153 it->push(&_cache);
154 it->push(&_pool_holder);
155 it->push(&bsm_entries().offsets());
156 it->push(&bsm_entries().bootstrap_methods());
157 it->push(&_resolved_klasses, MetaspaceClosure::_writable);
158
159 for (int i = 0; i < length(); i++) {
160 // The only MSO's embedded in the CP entries are Symbols:
161 // JVM_CONSTANT_String
162 // JVM_CONSTANT_Utf8
163 constantTag ctag = tag_at(i);
164 if (ctag.is_string() || ctag.is_utf8()) {
165 it->push(symbol_at_addr(i));
166 }
167 }
168 }
169
170 objArrayOop ConstantPool::resolved_references() const {
171 return _cache->resolved_references();
172 }
173
174 // Called from outside constant pool resolution where a resolved_reference array
175 // may not be present.
176 objArrayOop ConstantPool::resolved_references_or_null() const {
177 if (_cache == nullptr) {
178 return nullptr;
179 } else {
180 return _cache->resolved_references();
181 }
182 }
183
184 oop ConstantPool::resolved_reference_at(int index) const {
185 oop result = resolved_references()->obj_at(index);
186 assert(oopDesc::is_oop_or_null(result), "Must be oop");
187 return result;
188 }
189
190 // Use a CAS for multithreaded access
191 oop ConstantPool::set_resolved_reference_at(int index, oop new_result) {
192 assert(oopDesc::is_oop_or_null(new_result), "Must be oop");
193 return resolved_references()->replace_if_null(index, new_result);
194 }
195
196 // Create resolved_references array and mapping array for original cp indexes
197 // The ldc bytecode was rewritten to have the resolved reference array index so need a way
198 // to map it back for resolving and some unlikely miscellaneous uses.
199 // The objects created by invokedynamic are appended to this list.
200 void ConstantPool::initialize_resolved_references(ClassLoaderData* loader_data,
201 const intStack& reference_map,
202 int constant_pool_map_length,
203 TRAPS) {
204 // Initialized the resolved object cache.
205 int map_length = reference_map.length();
206 if (map_length > 0) {
207 // Only need mapping back to constant pool entries. The map isn't used for
208 // invokedynamic resolved_reference entries. For invokedynamic entries,
209 // the constant pool cache index has the mapping back to both the constant
210 // pool and to the resolved reference index.
211 if (constant_pool_map_length > 0) {
212 Array<u2>* om = MetadataFactory::new_array<u2>(loader_data, constant_pool_map_length, CHECK);
213
214 for (int i = 0; i < constant_pool_map_length; i++) {
215 int x = reference_map.at(i);
216 assert(x == (int)(jushort) x, "klass index is too big");
217 om->at_put(i, (jushort)x);
218 }
219 set_reference_map(om);
220 }
221
222 // Create Java array for holding resolved strings, methodHandles,
223 // methodTypes, invokedynamic and invokehandle appendix objects, etc.
224 objArrayOop stom = oopFactory::new_objArray(vmClasses::Object_klass(), map_length, CHECK);
225 HandleMark hm(THREAD);
226 Handle refs_handle (THREAD, stom); // must handleize.
227 set_resolved_references(loader_data->add_handle(refs_handle));
228
229 // Create a "scratch" copy of the resolved references array to archive
230 if (CDSConfig::is_dumping_heap()) {
231 objArrayOop scratch_references = oopFactory::new_objArray(vmClasses::Object_klass(), map_length, CHECK);
232 HeapShared::add_scratch_resolved_references(this, scratch_references);
233 }
234 }
235 }
236
237 void ConstantPool::allocate_resolved_klasses(ClassLoaderData* loader_data, int num_klasses, TRAPS) {
238 // A ConstantPool can't possibly have 0xffff valid class entries,
239 // because entry #0 must be CONSTANT_Invalid, and each class entry must refer to a UTF8
240 // entry for the class's name. So at most we will have 0xfffe class entries.
241 // This allows us to use 0xffff (ConstantPool::_temp_resolved_klass_index) to indicate
242 // UnresolvedKlass entries that are temporarily created during class redefinition.
243 assert(num_klasses < CPKlassSlot::_temp_resolved_klass_index, "sanity");
244 assert(resolved_klasses() == nullptr, "sanity");
245 Array<Klass*>* rk = MetadataFactory::new_array<Klass*>(loader_data, num_klasses, CHECK);
246 set_resolved_klasses(rk);
247 }
248
249 void ConstantPool::initialize_unresolved_klasses(ClassLoaderData* loader_data, TRAPS) {
250 int len = length();
251 int num_klasses = 0;
252 for (int i = 1; i <len; i++) {
253 switch (tag_at(i).value()) {
254 case JVM_CONSTANT_ClassIndex:
255 {
256 const int class_index = klass_index_at(i);
257 unresolved_klass_at_put(i, class_index, num_klasses++);
258 }
259 break;
260 #ifndef PRODUCT
261 case JVM_CONSTANT_Class:
262 case JVM_CONSTANT_UnresolvedClass:
263 case JVM_CONSTANT_UnresolvedClassInError:
264 // All of these should have been reverted back to ClassIndex before calling
265 // this function.
266 ShouldNotReachHere();
267 #endif
268 }
269 }
270 allocate_resolved_klasses(loader_data, num_klasses, THREAD);
271 }
272
273 // Hidden class support:
274 void ConstantPool::klass_at_put(int class_index, Klass* k) {
275 assert(k != nullptr, "must be valid klass");
276 CPKlassSlot kslot = klass_slot_at(class_index);
277 int resolved_klass_index = kslot.resolved_klass_index();
278 Klass** adr = resolved_klasses()->adr_at(resolved_klass_index);
279 AtomicAccess::release_store(adr, k);
280
281 // The interpreter assumes when the tag is stored, the klass is resolved
282 // and the Klass* non-null, so we need hardware store ordering here.
283 release_tag_at_put(class_index, JVM_CONSTANT_Class);
284 }
285
286 #if INCLUDE_CDS_JAVA_HEAP
287 template <typename Function>
288 void ConstantPool::iterate_archivable_resolved_references(Function function) {
289 objArrayOop rr = resolved_references();
290 if (rr != nullptr && cache() != nullptr && CDSConfig::is_dumping_method_handles()) {
291 Array<ResolvedIndyEntry>* indy_entries = cache()->resolved_indy_entries();
292 if (indy_entries != nullptr) {
293 for (int i = 0; i < indy_entries->length(); i++) {
294 ResolvedIndyEntry *rie = indy_entries->adr_at(i);
295 if (rie->is_resolved() && AOTConstantPoolResolver::is_resolution_deterministic(this, rie->constant_pool_index())) {
296 int rr_index = rie->resolved_references_index();
297 assert(resolved_reference_at(rr_index) != nullptr, "must exist");
298 function(rr_index);
299
300 // Save the BSM as well (sometimes the JIT looks up the BSM it for replay)
301 int indy_cp_index = rie->constant_pool_index();
302 int bsm_mh_cp_index = bootstrap_method_ref_index_at(indy_cp_index);
303 int bsm_rr_index = cp_to_object_index(bsm_mh_cp_index);
304 assert(resolved_reference_at(bsm_rr_index) != nullptr, "must exist");
305 function(bsm_rr_index);
306 }
307 }
308 }
309
310 Array<ResolvedMethodEntry>* method_entries = cache()->resolved_method_entries();
311 if (method_entries != nullptr) {
312 for (int i = 0; i < method_entries->length(); i++) {
313 ResolvedMethodEntry* rme = method_entries->adr_at(i);
314 const char* rejection_reason = nullptr;
315 if (rme->is_resolved(Bytecodes::_invokehandle) && rme->has_appendix() &&
316 cache()->can_archive_resolved_method(this, rme, rejection_reason)) {
317 int rr_index = rme->resolved_references_index();
318 assert(resolved_reference_at(rr_index) != nullptr, "must exist");
319 function(rr_index);
320 }
321 }
322 }
323 }
324 }
325
326 // Returns the _resolved_reference array after removing unarchivable items from it.
327 // Returns null if this class is not supported, or _resolved_reference doesn't exist.
328 objArrayOop ConstantPool::prepare_resolved_references_for_archiving() {
329 if (_cache == nullptr) {
330 return nullptr; // nothing to do
331 }
332
333 InstanceKlass *ik = pool_holder();
334 if (!SystemDictionaryShared::is_builtin_loader(ik->class_loader_data())) {
335 // Archiving resolved references for classes from non-builtin loaders
336 // is not yet supported.
337 return nullptr;
338 }
339
340 objArrayOop rr = resolved_references();
341 if (rr != nullptr) {
342 ResourceMark rm;
343 int rr_len = rr->length();
344 GrowableArray<bool> keep_resolved_refs(rr_len, rr_len, false);
345
346 iterate_archivable_resolved_references([&](int rr_index) {
347 keep_resolved_refs.at_put(rr_index, true);
348 });
349
350 objArrayOop scratch_rr = HeapShared::scratch_resolved_references(this);
351 Array<u2>* ref_map = reference_map();
352 int ref_map_len = ref_map == nullptr ? 0 : ref_map->length();
353 for (int i = 0; i < rr_len; i++) {
354 oop obj = rr->obj_at(i);
355 scratch_rr->obj_at_put(i, nullptr);
356 if (obj != nullptr) {
357 if (i < ref_map_len) {
358 int index = object_to_cp_index(i);
359 if (tag_at(index).is_string()) {
360 assert(java_lang_String::is_instance(obj), "must be");
361 if (!HeapShared::is_string_too_large_to_archive(obj)) {
362 scratch_rr->obj_at_put(i, obj);
363 }
364 continue;
365 }
366 }
367
368 if (keep_resolved_refs.at(i)) {
369 scratch_rr->obj_at_put(i, obj);
370 }
371 }
372 }
373 return scratch_rr;
374 }
375 return rr;
376 }
377 #endif
378
379 #if INCLUDE_CDS
380 // CDS support. Create a new resolved_references array.
381 void ConstantPool::restore_unshareable_info(TRAPS) {
382 if (!_pool_holder->is_linked() && !_pool_holder->is_rewritten()) {
383 return;
384 }
385 assert(is_constantPool(), "ensure C++ vtable is restored");
386 assert(on_stack(), "should always be set for constant pools in AOT cache");
387 assert(in_aot_cache(), "should always be set for constant pools in AOT cache");
388 if (is_for_method_handle_intrinsic()) {
389 // See the same check in remove_unshareable_info() below.
390 assert(cache() == nullptr, "must not have cpCache");
391 return;
392 }
393 assert(_cache != nullptr, "constant pool _cache should not be null");
394
395 // Only create the new resolved references array if it hasn't been attempted before
396 if (resolved_references() != nullptr) return;
397
398 if (vmClasses::Object_klass_is_loaded()) {
399 ClassLoaderData* loader_data = pool_holder()->class_loader_data();
400 #if INCLUDE_CDS_JAVA_HEAP
401 if (HeapShared::is_archived_heap_in_use() &&
402 _cache->archived_references() != nullptr) {
403 oop archived = _cache->archived_references();
404 // Create handle for the archived resolved reference array object
405 HandleMark hm(THREAD);
406 Handle refs_handle(THREAD, archived);
407 set_resolved_references(loader_data->add_handle(refs_handle));
408 _cache->clear_archived_references();
409 } else
410 #endif
411 {
412 // No mapped archived resolved reference array
413 // Recreate the object array and add to ClassLoaderData.
414 int map_length = resolved_reference_length();
415 if (map_length > 0) {
416 objArrayOop stom = oopFactory::new_objArray(vmClasses::Object_klass(), map_length, CHECK);
417 HandleMark hm(THREAD);
418 Handle refs_handle(THREAD, stom); // must handleize.
419 set_resolved_references(loader_data->add_handle(refs_handle));
420 }
421 }
422 }
423
424 if (CDSConfig::is_dumping_final_static_archive() && CDSConfig::is_dumping_heap() && resolved_references() != nullptr) {
425 objArrayOop scratch_references = oopFactory::new_objArray(vmClasses::Object_klass(), resolved_references()->length(), CHECK);
426 HeapShared::add_scratch_resolved_references(this, scratch_references);
427 }
428 }
429
430 void ConstantPool::remove_unshareable_info() {
431 // ConstantPools in AOT cache are in the RO region, so the _flags cannot be modified.
432 // The _on_stack flag is used to prevent ConstantPools from deallocation during
433 // class redefinition. Since such ConstantPools cannot be deallocated anyway,
434 // we always set _on_stack to true to avoid having to change _flags during runtime.
435 _flags |= (_on_stack | _in_aot_cache);
436
437 if (is_for_method_handle_intrinsic()) {
438 // This CP was created by Method::make_method_handle_intrinsic() and has nothing
439 // that need to be removed/restored. It has no cpCache since the intrinsic methods
440 // don't have any bytecodes.
441 assert(cache() == nullptr, "must not have cpCache");
442 return;
443 }
444
445 bool update_resolved_reference = true;
446 if (CDSConfig::is_dumping_final_static_archive()) {
447 ConstantPool* src_cp = ArchiveBuilder::current()->get_source_addr(this);
448 InstanceKlass* src_holder = src_cp->pool_holder();
449 if (src_holder->defined_by_other_loaders()) {
450 // Unregistered classes are not loaded in the AOT assembly phase. The resolved reference length
451 // is already saved during the training run.
452 precond(!src_holder->is_loaded());
453 precond(resolved_reference_length() >= 0);
454 precond(resolved_references() == nullptr);
455 update_resolved_reference = false;
456 }
457 }
458
459 // resolved_references(): remember its length. If it cannot be restored
460 // from the archived heap objects at run time, we need to dynamically allocate it.
461 if (update_resolved_reference && cache() != nullptr) {
462 set_resolved_reference_length(
463 resolved_references() != nullptr ? resolved_references()->length() : 0);
464 set_resolved_references(OopHandle());
465 }
466 remove_unshareable_entries();
467 }
468
469 static const char* get_type(Klass* k) {
470 const char* type;
471 Klass* src_k;
472 if (ArchiveBuilder::is_active() && ArchiveBuilder::current()->is_in_buffer_space(k)) {
473 src_k = ArchiveBuilder::current()->get_source_addr(k);
474 } else {
475 src_k = k;
476 }
477
478 if (src_k->is_objArray_klass()) {
479 src_k = ObjArrayKlass::cast(src_k)->bottom_klass();
480 assert(!src_k->is_objArray_klass(), "sanity");
481 }
482
483 if (src_k->is_typeArray_klass()) {
484 type = "prim";
485 } else {
486 InstanceKlass* src_ik = InstanceKlass::cast(src_k);
487 if (src_ik->defined_by_boot_loader()) {
488 return "boot";
489 } else if (src_ik->defined_by_platform_loader()) {
490 return "plat";
491 } else if (src_ik->defined_by_app_loader()) {
492 return "app";
493 } else {
494 return "unreg";
495 }
496 }
497
498 return type;
499 }
500
501 void ConstantPool::remove_unshareable_entries() {
502 ResourceMark rm;
503 log_info(aot, resolve)("Archiving CP entries for %s", pool_holder()->name()->as_C_string());
504 for (int cp_index = 1; cp_index < length(); cp_index++) { // cp_index 0 is unused
505 int cp_tag = tag_at(cp_index).value();
506 switch (cp_tag) {
507 case JVM_CONSTANT_UnresolvedClass:
508 ArchiveBuilder::alloc_stats()->record_klass_cp_entry(false, false);
509 break;
510 case JVM_CONSTANT_UnresolvedClassInError:
511 tag_at_put(cp_index, JVM_CONSTANT_UnresolvedClass);
512 ArchiveBuilder::alloc_stats()->record_klass_cp_entry(false, true);
513 break;
514 case JVM_CONSTANT_MethodHandleInError:
515 tag_at_put(cp_index, JVM_CONSTANT_MethodHandle);
516 break;
517 case JVM_CONSTANT_MethodTypeInError:
518 tag_at_put(cp_index, JVM_CONSTANT_MethodType);
519 break;
520 case JVM_CONSTANT_DynamicInError:
521 tag_at_put(cp_index, JVM_CONSTANT_Dynamic);
522 break;
523 case JVM_CONSTANT_Class:
524 remove_resolved_klass_if_non_deterministic(cp_index);
525 break;
526 default:
527 break;
528 }
529 }
530
531 if (cache() != nullptr) {
532 // cache() is null if this class is not yet linked.
533 cache()->remove_unshareable_info();
534 }
535 }
536
537 void ConstantPool::remove_resolved_klass_if_non_deterministic(int cp_index) {
538 assert(ArchiveBuilder::current()->is_in_buffer_space(this), "must be");
539 assert(tag_at(cp_index).is_klass(), "must be resolved");
540
541 bool can_archive;
542 Klass* k = nullptr;
543
544 if (CDSConfig::is_dumping_preimage_static_archive()) {
545 can_archive = false;
546 } else {
547 k = resolved_klass_at(cp_index);
548 if (k == nullptr) {
549 // We'd come here if the referenced class has been excluded via
550 // SystemDictionaryShared::is_excluded_class(). As a result, ArchiveBuilder
551 // has cleared the resolved_klasses()->at(...) pointer to null. Thus, we
552 // need to revert the tag to JVM_CONSTANT_UnresolvedClass.
553 can_archive = false;
554 } else {
555 ConstantPool* src_cp = ArchiveBuilder::current()->get_source_addr(this);
556 can_archive = AOTConstantPoolResolver::is_resolution_deterministic(src_cp, cp_index);
557 }
558 }
559
560 if (!can_archive) {
561 int resolved_klass_index = klass_slot_at(cp_index).resolved_klass_index();
562 // This might be at a safepoint but do this in the right order.
563 tag_at_put(cp_index, JVM_CONSTANT_UnresolvedClass);
564 resolved_klasses()->at_put(resolved_klass_index, nullptr);
565 }
566
567 LogStreamHandle(Trace, aot, resolve) log;
568 if (log.is_enabled()) {
569 ResourceMark rm;
570 log.print("%s klass CP entry [%3d]: %s %s",
571 (can_archive ? "archived" : "reverted"),
572 cp_index, pool_holder()->name()->as_C_string(), get_type(pool_holder()));
573 if (can_archive) {
574 log.print(" => %s %s%s", k->name()->as_C_string(), get_type(k),
575 (!k->is_instance_klass() || pool_holder()->is_subtype_of(k)) ? "" : " (not supertype)");
576 } else {
577 Symbol* name = klass_name_at(cp_index);
578 log.print(" => %s", name->as_C_string());
579 }
580 }
581
582 ArchiveBuilder::alloc_stats()->record_klass_cp_entry(can_archive, /*reverted=*/!can_archive);
583 }
584 #endif // INCLUDE_CDS
585
586 int ConstantPool::cp_to_object_index(int cp_index) {
587 // this is harder don't do this so much.
588 int i = reference_map()->find(checked_cast<u2>(cp_index));
589 // We might not find the index for jsr292 call.
590 return (i < 0) ? _no_index_sentinel : i;
591 }
592
593 void ConstantPool::string_at_put(int obj_index, oop str) {
594 oop result = set_resolved_reference_at(obj_index, str);
595 assert(result == nullptr || result == str, "Only set once or to the same string.");
596 }
597
598 void ConstantPool::trace_class_resolution(const constantPoolHandle& this_cp, Klass* k) {
599 ResourceMark rm;
600 int line_number = -1;
601 const char * source_file = nullptr;
602 if (JavaThread::current()->has_last_Java_frame()) {
603 // try to identify the method which called this function.
604 vframeStream vfst(JavaThread::current());
605 if (!vfst.at_end()) {
606 line_number = vfst.method()->line_number_from_bci(vfst.bci());
607 Symbol* s = vfst.method()->method_holder()->source_file_name();
608 if (s != nullptr) {
609 source_file = s->as_C_string();
610 }
611 }
612 }
613 if (k != this_cp->pool_holder()) {
614 // only print something if the classes are different
615 if (source_file != nullptr) {
616 log_debug(class, resolve)("%s %s %s:%d",
617 this_cp->pool_holder()->external_name(),
618 k->external_name(), source_file, line_number);
619 } else {
620 log_debug(class, resolve)("%s %s",
621 this_cp->pool_holder()->external_name(),
622 k->external_name());
623 }
624 }
625 }
626
627 Klass* ConstantPool::klass_at_impl(const constantPoolHandle& this_cp, int cp_index,
628 TRAPS) {
629 JavaThread* javaThread = THREAD;
630
631 // A resolved constantPool entry will contain a Klass*, otherwise a Symbol*.
632 // It is not safe to rely on the tag bit's here, since we don't have a lock, and
633 // the entry and tag is not updated atomically.
634 CPKlassSlot kslot = this_cp->klass_slot_at(cp_index);
635 int resolved_klass_index = kslot.resolved_klass_index();
636 int name_index = kslot.name_index();
637 assert(this_cp->tag_at(name_index).is_symbol(), "sanity");
638
639 // The tag must be JVM_CONSTANT_Class in order to read the correct value from
640 // the unresolved_klasses() array.
641 if (this_cp->tag_at(cp_index).is_klass()) {
642 Klass* klass = this_cp->resolved_klasses()->at(resolved_klass_index);
643 assert(klass != nullptr, "must be resolved");
644 return klass;
645 }
646
647 // This tag doesn't change back to unresolved class unless at a safepoint.
648 if (this_cp->tag_at(cp_index).is_unresolved_klass_in_error()) {
649 // The original attempt to resolve this constant pool entry failed so find the
650 // class of the original error and throw another error of the same class
651 // (JVMS 5.4.3).
652 // If there is a detail message, pass that detail message to the error.
653 // The JVMS does not strictly require us to duplicate the same detail message,
654 // or any internal exception fields such as cause or stacktrace. But since the
655 // detail message is often a class name or other literal string, we will repeat it
656 // if we can find it in the symbol table.
657 throw_resolution_error(this_cp, cp_index, CHECK_NULL);
658 ShouldNotReachHere();
659 }
660
661 HandleMark hm(THREAD);
662 Handle mirror_handle;
663 Symbol* name = this_cp->symbol_at(name_index);
664 Handle loader (THREAD, this_cp->pool_holder()->class_loader());
665
666 Klass* k;
667 {
668 // Turn off the single stepping while doing class resolution
669 JvmtiHideSingleStepping jhss(javaThread);
670 k = SystemDictionary::resolve_or_fail(name, loader, true, THREAD);
671 } // JvmtiHideSingleStepping jhss(javaThread);
672
673 if (!HAS_PENDING_EXCEPTION) {
674 // preserve the resolved klass from unloading
675 mirror_handle = Handle(THREAD, k->java_mirror());
676 // Do access check for klasses
677 verify_constant_pool_resolve(this_cp, k, THREAD);
678 }
679
680 // Failed to resolve class. We must record the errors so that subsequent attempts
681 // to resolve this constant pool entry fail with the same error (JVMS 5.4.3).
682 if (HAS_PENDING_EXCEPTION) {
683 save_and_throw_exception(this_cp, cp_index, constantTag(JVM_CONSTANT_UnresolvedClass), CHECK_NULL);
684 // If CHECK_NULL above doesn't return the exception, that means that
685 // some other thread has beaten us and has resolved the class.
686 // To preserve old behavior, we return the resolved class.
687 Klass* klass = this_cp->resolved_klasses()->at(resolved_klass_index);
688 assert(klass != nullptr, "must be resolved if exception was cleared");
689 return klass;
690 }
691
692 // logging for class+resolve.
693 if (log_is_enabled(Debug, class, resolve)){
694 trace_class_resolution(this_cp, k);
695 }
696
697 // The interpreter assumes when the tag is stored, the klass is resolved
698 // and the Klass* stored in _resolved_klasses is non-null, so we need
699 // hardware store ordering here.
700 // We also need to CAS to not overwrite an error from a racing thread.
701 Klass** adr = this_cp->resolved_klasses()->adr_at(resolved_klass_index);
702 AtomicAccess::release_store(adr, k);
703
704 jbyte old_tag = AtomicAccess::cmpxchg((jbyte*)this_cp->tag_addr_at(cp_index),
705 (jbyte)JVM_CONSTANT_UnresolvedClass,
706 (jbyte)JVM_CONSTANT_Class);
707
708 // We need to recheck exceptions from racing thread and return the same.
709 if (old_tag == JVM_CONSTANT_UnresolvedClassInError) {
710 // Remove klass.
711 AtomicAccess::store(adr, (Klass*)nullptr);
712 throw_resolution_error(this_cp, cp_index, CHECK_NULL);
713 }
714
715 return k;
716 }
717
718
719 // Does not update ConstantPool* - to avoid any exception throwing. Used
720 // by compiler and exception handling. Also used to avoid classloads for
721 // instanceof operations. Returns null if the class has not been loaded or
722 // if the verification of constant pool failed
723 Klass* ConstantPool::klass_at_if_loaded(const constantPoolHandle& this_cp, int which) {
724 CPKlassSlot kslot = this_cp->klass_slot_at(which);
725 int resolved_klass_index = kslot.resolved_klass_index();
726 int name_index = kslot.name_index();
727 assert(this_cp->tag_at(name_index).is_symbol(), "sanity");
728
729 if (this_cp->tag_at(which).is_klass()) {
730 Klass* k = this_cp->resolved_klasses()->at(resolved_klass_index);
731 assert(k != nullptr, "must be resolved");
732 return k;
733 } else if (this_cp->tag_at(which).is_unresolved_klass_in_error()) {
734 return nullptr;
735 } else {
736 Thread* current = Thread::current();
737 HandleMark hm(current);
738 Symbol* name = this_cp->symbol_at(name_index);
739 oop loader = this_cp->pool_holder()->class_loader();
740 Handle h_loader (current, loader);
741 Klass* k = SystemDictionary::find_instance_klass(current, name, h_loader);
742
743 // Avoid constant pool verification at a safepoint, as it takes the Module_lock.
744 if (k != nullptr && current->is_Java_thread()) {
745 // Make sure that resolving is legal
746 JavaThread* THREAD = JavaThread::cast(current); // For exception macros.
747 ExceptionMark em(THREAD);
748 // return null if verification fails
749 verify_constant_pool_resolve(this_cp, k, THREAD);
750 if (HAS_PENDING_EXCEPTION) {
751 CLEAR_PENDING_EXCEPTION;
752 return nullptr;
753 }
754 return k;
755 } else {
756 return k;
757 }
758 }
759 }
760
761 Method* ConstantPool::method_at_if_loaded(const constantPoolHandle& cpool,
762 int which) {
763 if (cpool->cache() == nullptr) return nullptr; // nothing to load yet
764 if (!(which >= 0 && which < cpool->resolved_method_entries_length())) {
765 // FIXME: should be an assert
766 log_debug(class, resolve)("bad BSM %d in:", which); cpool->print();
767 return nullptr;
768 }
769 return cpool->cache()->method_if_resolved(which);
770 }
771
772
773 bool ConstantPool::has_appendix_at_if_loaded(const constantPoolHandle& cpool, int which, Bytecodes::Code code) {
774 if (cpool->cache() == nullptr) return false; // nothing to load yet
775 if (code == Bytecodes::_invokedynamic) {
776 return cpool->resolved_indy_entry_at(which)->has_appendix();
777 } else {
778 return cpool->resolved_method_entry_at(which)->has_appendix();
779 }
780 }
781
782 oop ConstantPool::appendix_at_if_loaded(const constantPoolHandle& cpool, int which, Bytecodes::Code code) {
783 if (cpool->cache() == nullptr) return nullptr; // nothing to load yet
784 if (code == Bytecodes::_invokedynamic) {
785 return cpool->resolved_reference_from_indy(which);
786 } else {
787 return cpool->cache()->appendix_if_resolved(which);
788 }
789 }
790
791
792 bool ConstantPool::has_local_signature_at_if_loaded(const constantPoolHandle& cpool, int which, Bytecodes::Code code) {
793 if (cpool->cache() == nullptr) return false; // nothing to load yet
794 if (code == Bytecodes::_invokedynamic) {
795 return cpool->resolved_indy_entry_at(which)->has_local_signature();
796 } else {
797 return cpool->resolved_method_entry_at(which)->has_local_signature();
798 }
799 }
800
801 // Translate index, which could be CPCache index or Indy index, to a constant pool index
802 int ConstantPool::to_cp_index(int index, Bytecodes::Code code) {
803 assert(cache() != nullptr, "'index' is a rewritten index so this class must have been rewritten");
804 switch(code) {
805 case Bytecodes::_invokedynamic:
806 return invokedynamic_bootstrap_ref_index_at(index);
807 case Bytecodes::_getfield:
808 case Bytecodes::_getstatic:
809 case Bytecodes::_putfield:
810 case Bytecodes::_putstatic:
811 return resolved_field_entry_at(index)->constant_pool_index();
812 case Bytecodes::_invokeinterface:
813 case Bytecodes::_invokehandle:
814 case Bytecodes::_invokespecial:
815 case Bytecodes::_invokestatic:
816 case Bytecodes::_invokevirtual:
817 case Bytecodes::_fast_invokevfinal: // Bytecode interpreter uses this
818 return resolved_method_entry_at(index)->constant_pool_index();
819 default:
820 fatal("Unexpected bytecode: %s", Bytecodes::name(code));
821 }
822 }
823
824 bool ConstantPool::is_resolved(int index, Bytecodes::Code code) {
825 assert(cache() != nullptr, "'index' is a rewritten index so this class must have been rewritten");
826 switch(code) {
827 case Bytecodes::_invokedynamic:
828 return resolved_indy_entry_at(index)->is_resolved();
829
830 case Bytecodes::_getfield:
831 case Bytecodes::_getstatic:
832 case Bytecodes::_putfield:
833 case Bytecodes::_putstatic:
834 return resolved_field_entry_at(index)->is_resolved(code);
835
836 case Bytecodes::_invokeinterface:
837 case Bytecodes::_invokehandle:
838 case Bytecodes::_invokespecial:
839 case Bytecodes::_invokestatic:
840 case Bytecodes::_invokevirtual:
841 case Bytecodes::_fast_invokevfinal: // Bytecode interpreter uses this
842 return resolved_method_entry_at(index)->is_resolved(code);
843
844 default:
845 fatal("Unexpected bytecode: %s", Bytecodes::name(code));
846 }
847 }
848
849 u2 ConstantPool::uncached_name_and_type_ref_index_at(int cp_index) {
850 if (tag_at(cp_index).has_bootstrap()) {
851 u2 pool_index = bootstrap_name_and_type_ref_index_at(cp_index);
852 assert(tag_at(pool_index).is_name_and_type(), "");
853 return pool_index;
854 }
855 assert(tag_at(cp_index).is_field_or_method(), "Corrupted constant pool");
856 assert(!tag_at(cp_index).has_bootstrap(), "Must be handled above");
857 jint ref_index = *int_at_addr(cp_index);
858 return extract_high_short_from_int(ref_index);
859 }
860
861 u2 ConstantPool::name_and_type_ref_index_at(int index, Bytecodes::Code code) {
862 return uncached_name_and_type_ref_index_at(to_cp_index(index, code));
863 }
864
865 constantTag ConstantPool::tag_ref_at(int which, Bytecodes::Code code) {
866 // which may be either a Constant Pool index or a rewritten index
867 int pool_index = which;
868 assert(cache() != nullptr, "'index' is a rewritten index so this class must have been rewritten");
869 pool_index = to_cp_index(which, code);
870 return tag_at(pool_index);
871 }
872
873 u2 ConstantPool::uncached_klass_ref_index_at(int cp_index) {
874 assert(tag_at(cp_index).is_field_or_method(), "Corrupted constant pool");
875 jint ref_index = *int_at_addr(cp_index);
876 return extract_low_short_from_int(ref_index);
877 }
878
879 u2 ConstantPool::klass_ref_index_at(int index, Bytecodes::Code code) {
880 assert(code != Bytecodes::_invokedynamic,
881 "an invokedynamic instruction does not have a klass");
882 return uncached_klass_ref_index_at(to_cp_index(index, code));
883 }
884
885 void ConstantPool::verify_constant_pool_resolve(const constantPoolHandle& this_cp, Klass* k, TRAPS) {
886 if (!(k->is_instance_klass() || k->is_objArray_klass())) {
887 return; // short cut, typeArray klass is always accessible
888 }
889 Klass* holder = this_cp->pool_holder();
890 LinkResolver::check_klass_accessibility(holder, k, CHECK);
891 }
892
893
894 u2 ConstantPool::name_ref_index_at(int cp_index) {
895 jint ref_index = name_and_type_at(cp_index);
896 return extract_low_short_from_int(ref_index);
897 }
898
899
900 u2 ConstantPool::signature_ref_index_at(int cp_index) {
901 jint ref_index = name_and_type_at(cp_index);
902 return extract_high_short_from_int(ref_index);
903 }
904
905
906 Klass* ConstantPool::klass_ref_at(int which, Bytecodes::Code code, TRAPS) {
907 return klass_at(klass_ref_index_at(which, code), THREAD);
908 }
909
910 Symbol* ConstantPool::klass_name_at(int cp_index) const {
911 return symbol_at(klass_slot_at(cp_index).name_index());
912 }
913
914 Symbol* ConstantPool::klass_ref_at_noresolve(int which, Bytecodes::Code code) {
915 jint ref_index = klass_ref_index_at(which, code);
916 return klass_at_noresolve(ref_index);
917 }
918
919 Symbol* ConstantPool::uncached_klass_ref_at_noresolve(int cp_index) {
920 jint ref_index = uncached_klass_ref_index_at(cp_index);
921 return klass_at_noresolve(ref_index);
922 }
923
924 char* ConstantPool::string_at_noresolve(int cp_index) {
925 return unresolved_string_at(cp_index)->as_C_string();
926 }
927
928 BasicType ConstantPool::basic_type_for_signature_at(int cp_index) const {
929 return Signature::basic_type(symbol_at(cp_index));
930 }
931
932
933 void ConstantPool::resolve_string_constants_impl(const constantPoolHandle& this_cp, TRAPS) {
934 for (int index = 1; index < this_cp->length(); index++) { // Index 0 is unused
935 if (this_cp->tag_at(index).is_string()) {
936 this_cp->string_at(index, CHECK);
937 }
938 }
939 }
940
941 static const char* exception_message(const constantPoolHandle& this_cp, int which, constantTag tag, oop pending_exception) {
942 // Note: caller needs ResourceMark
943
944 // Dig out the detailed message to reuse if possible
945 const char* msg = java_lang_Throwable::message_as_utf8(pending_exception);
946 if (msg != nullptr) {
947 return msg;
948 }
949
950 Symbol* message = nullptr;
951 // Return specific message for the tag
952 switch (tag.value()) {
953 case JVM_CONSTANT_UnresolvedClass:
954 // return the class name in the error message
955 message = this_cp->klass_name_at(which);
956 break;
957 case JVM_CONSTANT_MethodHandle:
958 // return the method handle name in the error message
959 message = this_cp->method_handle_name_ref_at(which);
960 break;
961 case JVM_CONSTANT_MethodType:
962 // return the method type signature in the error message
963 message = this_cp->method_type_signature_at(which);
964 break;
965 case JVM_CONSTANT_Dynamic:
966 // return the name of the condy in the error message
967 message = this_cp->uncached_name_ref_at(which);
968 break;
969 default:
970 ShouldNotReachHere();
971 }
972
973 return message != nullptr ? message->as_C_string() : nullptr;
974 }
975
976 static void add_resolution_error(JavaThread* current, const constantPoolHandle& this_cp, int which,
977 constantTag tag, oop pending_exception) {
978
979 ResourceMark rm(current);
980 Symbol* error = pending_exception->klass()->name();
981 oop cause = java_lang_Throwable::cause(pending_exception);
982
983 // Also dig out the exception cause, if present.
984 Symbol* cause_sym = nullptr;
985 const char* cause_msg = nullptr;
986 if (cause != nullptr && cause != pending_exception) {
987 cause_sym = cause->klass()->name();
988 cause_msg = java_lang_Throwable::message_as_utf8(cause);
989 }
990
991 const char* message = exception_message(this_cp, which, tag, pending_exception);
992 SystemDictionary::add_resolution_error(this_cp, which, error, message, cause_sym, cause_msg);
993 }
994
995
996 void ConstantPool::throw_resolution_error(const constantPoolHandle& this_cp, int which, TRAPS) {
997 ResourceMark rm(THREAD);
998 const char* message = nullptr;
999 Symbol* cause = nullptr;
1000 const char* cause_msg = nullptr;
1001 Symbol* error = SystemDictionary::find_resolution_error(this_cp, which, &message, &cause, &cause_msg);
1002 assert(error != nullptr, "checking");
1003
1004 CLEAR_PENDING_EXCEPTION;
1005 if (message != nullptr) {
1006 if (cause != nullptr) {
1007 Handle h_cause = Exceptions::new_exception(THREAD, cause, cause_msg);
1008 THROW_MSG_CAUSE(error, message, h_cause);
1009 } else {
1010 THROW_MSG(error, message);
1011 }
1012 } else {
1013 if (cause != nullptr) {
1014 Handle h_cause = Exceptions::new_exception(THREAD, cause, cause_msg);
1015 THROW_CAUSE(error, h_cause);
1016 } else {
1017 THROW(error);
1018 }
1019 }
1020 }
1021
1022 // If resolution for Class, Dynamic constant, MethodHandle or MethodType fails, save the
1023 // exception in the resolution error table, so that the same exception is thrown again.
1024 void ConstantPool::save_and_throw_exception(const constantPoolHandle& this_cp, int cp_index,
1025 constantTag tag, TRAPS) {
1026
1027 int error_tag = tag.error_value();
1028
1029 if (!PENDING_EXCEPTION->
1030 is_a(vmClasses::LinkageError_klass())) {
1031 // Just throw the exception and don't prevent these classes from
1032 // being loaded due to virtual machine errors like StackOverflow
1033 // and OutOfMemoryError, etc, or if the thread was hit by stop()
1034 // Needs clarification to section 5.4.3 of the VM spec (see 6308271)
1035 } else if (this_cp->tag_at(cp_index).value() != error_tag) {
1036 add_resolution_error(THREAD, this_cp, cp_index, tag, PENDING_EXCEPTION);
1037 // CAS in the tag. If a thread beat us to registering this error that's fine.
1038 // If another thread resolved the reference, this is a race condition. This
1039 // thread may have had a security manager or something temporary.
1040 // This doesn't deterministically get an error. So why do we save this?
1041 // We save this because jvmti can add classes to the bootclass path after
1042 // this error, so it needs to get the same error if the error is first.
1043 jbyte old_tag = AtomicAccess::cmpxchg((jbyte*)this_cp->tag_addr_at(cp_index),
1044 (jbyte)tag.value(),
1045 (jbyte)error_tag);
1046 if (old_tag != error_tag && old_tag != tag.value()) {
1047 // MethodHandles and MethodType doesn't change to resolved version.
1048 assert(this_cp->tag_at(cp_index).is_klass(), "Wrong tag value");
1049 // Forget the exception and use the resolved class.
1050 CLEAR_PENDING_EXCEPTION;
1051 }
1052 } else {
1053 // some other thread put this in error state
1054 throw_resolution_error(this_cp, cp_index, CHECK);
1055 }
1056 }
1057
1058 constantTag ConstantPool::constant_tag_at(int cp_index) {
1059 constantTag tag = tag_at(cp_index);
1060 if (tag.is_dynamic_constant()) {
1061 BasicType bt = basic_type_for_constant_at(cp_index);
1062 return constantTag(constantTag::type2tag(bt));
1063 }
1064 return tag;
1065 }
1066
1067 BasicType ConstantPool::basic_type_for_constant_at(int cp_index) {
1068 constantTag tag = tag_at(cp_index);
1069 if (tag.is_dynamic_constant() ||
1070 tag.is_dynamic_constant_in_error()) {
1071 // have to look at the signature for this one
1072 Symbol* constant_type = uncached_signature_ref_at(cp_index);
1073 return Signature::basic_type(constant_type);
1074 }
1075 return tag.basic_type();
1076 }
1077
1078 // Called to resolve constants in the constant pool and return an oop.
1079 // Some constant pool entries cache their resolved oop. This is also
1080 // called to create oops from constants to use in arguments for invokedynamic
1081 oop ConstantPool::resolve_constant_at_impl(const constantPoolHandle& this_cp,
1082 int cp_index, int cache_index,
1083 bool* status_return, TRAPS) {
1084 oop result_oop = nullptr;
1085
1086 if (cache_index == _possible_index_sentinel) {
1087 // It is possible that this constant is one which is cached in the objects.
1088 // We'll do a linear search. This should be OK because this usage is rare.
1089 // FIXME: If bootstrap specifiers stress this code, consider putting in
1090 // a reverse index. Binary search over a short array should do it.
1091 assert(cp_index > 0, "valid constant pool index");
1092 cache_index = this_cp->cp_to_object_index(cp_index);
1093 }
1094 assert(cache_index == _no_index_sentinel || cache_index >= 0, "");
1095 assert(cp_index == _no_index_sentinel || cp_index >= 0, "");
1096
1097 if (cache_index >= 0) {
1098 result_oop = this_cp->resolved_reference_at(cache_index);
1099 if (result_oop != nullptr) {
1100 if (result_oop == Universe::the_null_sentinel()) {
1101 DEBUG_ONLY(int temp_index = (cp_index >= 0 ? cp_index : this_cp->object_to_cp_index(cache_index)));
1102 assert(this_cp->tag_at(temp_index).is_dynamic_constant(), "only condy uses the null sentinel");
1103 result_oop = nullptr;
1104 }
1105 if (status_return != nullptr) (*status_return) = true;
1106 return result_oop;
1107 // That was easy...
1108 }
1109 cp_index = this_cp->object_to_cp_index(cache_index);
1110 }
1111
1112 jvalue prim_value; // temp used only in a few cases below
1113
1114 constantTag tag = this_cp->tag_at(cp_index);
1115
1116 if (status_return != nullptr) {
1117 // don't trigger resolution if the constant might need it
1118 switch (tag.value()) {
1119 case JVM_CONSTANT_Class:
1120 assert(this_cp->resolved_klass_at(cp_index) != nullptr, "must be resolved");
1121 break;
1122 case JVM_CONSTANT_String:
1123 case JVM_CONSTANT_Integer:
1124 case JVM_CONSTANT_Float:
1125 case JVM_CONSTANT_Long:
1126 case JVM_CONSTANT_Double:
1127 // these guys trigger OOM at worst
1128 break;
1129 default:
1130 (*status_return) = false;
1131 return nullptr;
1132 }
1133 // from now on there is either success or an OOME
1134 (*status_return) = true;
1135 }
1136
1137 switch (tag.value()) {
1138
1139 case JVM_CONSTANT_UnresolvedClass:
1140 case JVM_CONSTANT_Class:
1141 {
1142 assert(cache_index == _no_index_sentinel, "should not have been set");
1143 Klass* resolved = klass_at_impl(this_cp, cp_index, CHECK_NULL);
1144 // ldc wants the java mirror.
1145 result_oop = resolved->java_mirror();
1146 break;
1147 }
1148
1149 case JVM_CONSTANT_Dynamic:
1150 { PerfTraceTimedEvent timer(ClassLoader::perf_resolve_invokedynamic_time(),
1151 ClassLoader::perf_resolve_invokedynamic_count());
1152
1153 // Resolve the Dynamically-Computed constant to invoke the BSM in order to obtain the resulting oop.
1154 BootstrapInfo bootstrap_specifier(this_cp, cp_index);
1155
1156 // The initial step in resolving an unresolved symbolic reference to a
1157 // dynamically-computed constant is to resolve the symbolic reference to a
1158 // method handle which will be the bootstrap method for the dynamically-computed
1159 // constant. If resolution of the java.lang.invoke.MethodHandle for the bootstrap
1160 // method fails, then a MethodHandleInError is stored at the corresponding
1161 // bootstrap method's CP index for the CONSTANT_MethodHandle_info. No need to
1162 // set a DynamicConstantInError here since any subsequent use of this
1163 // bootstrap method will encounter the resolution of MethodHandleInError.
1164 // Both the first, (resolution of the BSM and its static arguments), and the second tasks,
1165 // (invocation of the BSM), of JVMS Section 5.4.3.6 occur within invoke_bootstrap_method()
1166 // for the bootstrap_specifier created above.
1167 SystemDictionary::invoke_bootstrap_method(bootstrap_specifier, THREAD);
1168 Exceptions::wrap_dynamic_exception(/* is_indy */ false, THREAD);
1169 if (HAS_PENDING_EXCEPTION) {
1170 // Resolution failure of the dynamically-computed constant, save_and_throw_exception
1171 // will check for a LinkageError and store a DynamicConstantInError.
1172 save_and_throw_exception(this_cp, cp_index, tag, CHECK_NULL);
1173 }
1174 result_oop = bootstrap_specifier.resolved_value()();
1175 BasicType type = Signature::basic_type(bootstrap_specifier.signature());
1176 if (!is_reference_type(type)) {
1177 // Make sure the primitive value is properly boxed.
1178 // This is a JDK responsibility.
1179 const char* fail = nullptr;
1180 if (result_oop == nullptr) {
1181 fail = "null result instead of box";
1182 } else if (!is_java_primitive(type)) {
1183 // FIXME: support value types via unboxing
1184 fail = "can only handle references and primitives";
1185 } else if (!java_lang_boxing_object::is_instance(result_oop, type)) {
1186 fail = "primitive is not properly boxed";
1187 }
1188 if (fail != nullptr) {
1189 // Since this exception is not a LinkageError, throw exception
1190 // but do not save a DynamicInError resolution result.
1191 // See section 5.4.3 of the VM spec.
1192 THROW_MSG_NULL(vmSymbols::java_lang_InternalError(), fail);
1193 }
1194 }
1195
1196 LogTarget(Debug, methodhandles, condy) lt_condy;
1197 if (lt_condy.is_enabled()) {
1198 LogStream ls(lt_condy);
1199 bootstrap_specifier.print_msg_on(&ls, "resolve_constant_at_impl");
1200 }
1201 break;
1202 }
1203
1204 case JVM_CONSTANT_String:
1205 assert(cache_index != _no_index_sentinel, "should have been set");
1206 result_oop = string_at_impl(this_cp, cp_index, cache_index, CHECK_NULL);
1207 break;
1208
1209 case JVM_CONSTANT_MethodHandle:
1210 { PerfTraceTimedEvent timer(ClassLoader::perf_resolve_method_handle_time(),
1211 ClassLoader::perf_resolve_method_handle_count());
1212
1213 int ref_kind = this_cp->method_handle_ref_kind_at(cp_index);
1214 int callee_index = this_cp->method_handle_klass_index_at(cp_index);
1215 Symbol* name = this_cp->method_handle_name_ref_at(cp_index);
1216 Symbol* signature = this_cp->method_handle_signature_ref_at(cp_index);
1217 constantTag m_tag = this_cp->tag_at(this_cp->method_handle_index_at(cp_index));
1218 { ResourceMark rm(THREAD);
1219 log_debug(class, resolve)("resolve JVM_CONSTANT_MethodHandle:%d [%d/%d/%d] %s.%s",
1220 ref_kind, cp_index, this_cp->method_handle_index_at(cp_index),
1221 callee_index, name->as_C_string(), signature->as_C_string());
1222 }
1223
1224 Klass* callee = klass_at_impl(this_cp, callee_index, THREAD);
1225 if (HAS_PENDING_EXCEPTION) {
1226 save_and_throw_exception(this_cp, cp_index, tag, CHECK_NULL);
1227 }
1228
1229 // Check constant pool method consistency
1230 if ((callee->is_interface() && m_tag.is_method()) ||
1231 (!callee->is_interface() && m_tag.is_interface_method())) {
1232 ResourceMark rm(THREAD);
1233 stringStream ss;
1234 ss.print("Inconsistent constant pool data in classfile for class %s. "
1235 "Method '", callee->name()->as_C_string());
1236 signature->print_as_signature_external_return_type(&ss);
1237 ss.print(" %s(", name->as_C_string());
1238 signature->print_as_signature_external_parameters(&ss);
1239 ss.print(")' at index %d is %s and should be %s",
1240 cp_index,
1241 callee->is_interface() ? "CONSTANT_MethodRef" : "CONSTANT_InterfaceMethodRef",
1242 callee->is_interface() ? "CONSTANT_InterfaceMethodRef" : "CONSTANT_MethodRef");
1243 // Names are all known to be < 64k so we know this formatted message is not excessively large.
1244 Exceptions::fthrow(THREAD_AND_LOCATION, vmSymbols::java_lang_IncompatibleClassChangeError(), "%s", ss.as_string());
1245 save_and_throw_exception(this_cp, cp_index, tag, CHECK_NULL);
1246 }
1247
1248 Klass* klass = this_cp->pool_holder();
1249 HandleMark hm(THREAD);
1250 Handle value = SystemDictionary::link_method_handle_constant(klass, ref_kind,
1251 callee, name, signature,
1252 THREAD);
1253 if (HAS_PENDING_EXCEPTION) {
1254 save_and_throw_exception(this_cp, cp_index, tag, CHECK_NULL);
1255 }
1256 result_oop = value();
1257 break;
1258 }
1259
1260 case JVM_CONSTANT_MethodType:
1261 { PerfTraceTimedEvent timer(ClassLoader::perf_resolve_method_type_time(),
1262 ClassLoader::perf_resolve_method_type_count());
1263
1264 Symbol* signature = this_cp->method_type_signature_at(cp_index);
1265 { ResourceMark rm(THREAD);
1266 log_debug(class, resolve)("resolve JVM_CONSTANT_MethodType [%d/%d] %s",
1267 cp_index, this_cp->method_type_index_at(cp_index),
1268 signature->as_C_string());
1269 }
1270 Klass* klass = this_cp->pool_holder();
1271 HandleMark hm(THREAD);
1272 Handle value = SystemDictionary::find_method_handle_type(signature, klass, THREAD);
1273 result_oop = value();
1274 if (HAS_PENDING_EXCEPTION) {
1275 save_and_throw_exception(this_cp, cp_index, tag, CHECK_NULL);
1276 }
1277 break;
1278 }
1279
1280 case JVM_CONSTANT_Integer:
1281 assert(cache_index == _no_index_sentinel, "should not have been set");
1282 prim_value.i = this_cp->int_at(cp_index);
1283 result_oop = java_lang_boxing_object::create(T_INT, &prim_value, CHECK_NULL);
1284 break;
1285
1286 case JVM_CONSTANT_Float:
1287 assert(cache_index == _no_index_sentinel, "should not have been set");
1288 prim_value.f = this_cp->float_at(cp_index);
1289 result_oop = java_lang_boxing_object::create(T_FLOAT, &prim_value, CHECK_NULL);
1290 break;
1291
1292 case JVM_CONSTANT_Long:
1293 assert(cache_index == _no_index_sentinel, "should not have been set");
1294 prim_value.j = this_cp->long_at(cp_index);
1295 result_oop = java_lang_boxing_object::create(T_LONG, &prim_value, CHECK_NULL);
1296 break;
1297
1298 case JVM_CONSTANT_Double:
1299 assert(cache_index == _no_index_sentinel, "should not have been set");
1300 prim_value.d = this_cp->double_at(cp_index);
1301 result_oop = java_lang_boxing_object::create(T_DOUBLE, &prim_value, CHECK_NULL);
1302 break;
1303
1304 case JVM_CONSTANT_UnresolvedClassInError:
1305 case JVM_CONSTANT_DynamicInError:
1306 case JVM_CONSTANT_MethodHandleInError:
1307 case JVM_CONSTANT_MethodTypeInError:
1308 throw_resolution_error(this_cp, cp_index, CHECK_NULL);
1309 break;
1310
1311 default:
1312 fatal("unexpected constant tag at CP %p[%d/%d] = %d", this_cp(), cp_index, cache_index, tag.value());
1313 break;
1314 }
1315
1316 if (cache_index >= 0) {
1317 // Benign race condition: resolved_references may already be filled in.
1318 // The important thing here is that all threads pick up the same result.
1319 // It doesn't matter which racing thread wins, as long as only one
1320 // result is used by all threads, and all future queries.
1321 oop new_result = (result_oop == nullptr ? Universe::the_null_sentinel() : result_oop);
1322 oop old_result = this_cp->set_resolved_reference_at(cache_index, new_result);
1323 if (old_result == nullptr) {
1324 return result_oop; // was installed
1325 } else {
1326 // Return the winning thread's result. This can be different than
1327 // the result here for MethodHandles.
1328 if (old_result == Universe::the_null_sentinel())
1329 old_result = nullptr;
1330 return old_result;
1331 }
1332 } else {
1333 assert(result_oop != Universe::the_null_sentinel(), "");
1334 return result_oop;
1335 }
1336 }
1337
1338 oop ConstantPool::uncached_string_at(int cp_index, TRAPS) {
1339 Symbol* sym = unresolved_string_at(cp_index);
1340 oop str = StringTable::intern(sym, CHECK_(nullptr));
1341 assert(java_lang_String::is_instance(str), "must be string");
1342 return str;
1343 }
1344
1345 void ConstantPool::copy_bootstrap_arguments_at_impl(const constantPoolHandle& this_cp, int cp_index,
1346 int start_arg, int end_arg,
1347 objArrayHandle info, int pos,
1348 bool must_resolve, Handle if_not_available,
1349 TRAPS) {
1350 int limit = pos + end_arg - start_arg;
1351 // checks: cp_index in range [0..this_cp->length),
1352 // tag at cp_index, start..end in range [0..this_cp->bootstrap_argument_count],
1353 // info array non-null, pos..limit in [0..info.length]
1354 if ((0 >= cp_index || cp_index >= this_cp->length()) ||
1355 !(this_cp->tag_at(cp_index).is_invoke_dynamic() ||
1356 this_cp->tag_at(cp_index).is_dynamic_constant()) ||
1357 (0 > start_arg || start_arg > end_arg) ||
1358 (end_arg > this_cp->bootstrap_argument_count_at(cp_index)) ||
1359 (0 > pos || pos > limit) ||
1360 (info.is_null() || limit > info->length())) {
1361 // An index or something else went wrong; throw an error.
1362 // Since this is an internal API, we don't expect this,
1363 // so we don't bother to craft a nice message.
1364 THROW_MSG(vmSymbols::java_lang_LinkageError(), "bad BSM argument access");
1365 }
1366 // now we can loop safely
1367 int info_i = pos;
1368 for (int i = start_arg; i < end_arg; i++) {
1369 int arg_index = this_cp->bootstrap_argument_index_at(cp_index, i);
1370 oop arg_oop;
1371 if (must_resolve) {
1372 arg_oop = this_cp->resolve_possibly_cached_constant_at(arg_index, CHECK);
1373 } else {
1374 bool found_it = false;
1375 arg_oop = this_cp->find_cached_constant_at(arg_index, found_it, CHECK);
1376 if (!found_it) arg_oop = if_not_available();
1377 }
1378 info->obj_at_put(info_i++, arg_oop);
1379 }
1380 }
1381
1382 oop ConstantPool::string_at_impl(const constantPoolHandle& this_cp, int cp_index, int obj_index, TRAPS) {
1383 // If the string has already been interned, this entry will be non-null
1384 oop str = this_cp->resolved_reference_at(obj_index);
1385 assert(str != Universe::the_null_sentinel(), "");
1386 if (str != nullptr) return str;
1387 Symbol* sym = this_cp->unresolved_string_at(cp_index);
1388 str = StringTable::intern(sym, CHECK_(nullptr));
1389 this_cp->string_at_put(obj_index, str);
1390 assert(java_lang_String::is_instance(str), "must be string");
1391 return str;
1392 }
1393
1394
1395 bool ConstantPool::klass_name_at_matches(const InstanceKlass* k, int cp_index) {
1396 // Names are interned, so we can compare Symbol*s directly
1397 Symbol* cp_name = klass_name_at(cp_index);
1398 return (cp_name == k->name());
1399 }
1400
1401
1402 // Iterate over symbols and decrement ones which are Symbol*s
1403 // This is done during GC.
1404 // Only decrement the UTF8 symbols. Strings point to
1405 // these symbols but didn't increment the reference count.
1406 void ConstantPool::unreference_symbols() {
1407 for (int index = 1; index < length(); index++) { // Index 0 is unused
1408 constantTag tag = tag_at(index);
1409 if (tag.is_symbol()) {
1410 symbol_at(index)->decrement_refcount();
1411 }
1412 }
1413 }
1414
1415
1416 // Compare this constant pool's entry at index1 to the constant pool
1417 // cp2's entry at index2.
1418 bool ConstantPool::compare_entry_to(int index1, const constantPoolHandle& cp2,
1419 int index2) {
1420
1421 // The error tags are equivalent to non-error tags when comparing
1422 jbyte t1 = tag_at(index1).non_error_value();
1423 jbyte t2 = cp2->tag_at(index2).non_error_value();
1424
1425 // Some classes are pre-resolved (like Throwable) which may lead to
1426 // consider it as a different entry. We then revert them back temporarily
1427 // to ensure proper comparison.
1428 if (t1 == JVM_CONSTANT_Class) {
1429 t1 = JVM_CONSTANT_UnresolvedClass;
1430 }
1431 if (t2 == JVM_CONSTANT_Class) {
1432 t2 = JVM_CONSTANT_UnresolvedClass;
1433 }
1434
1435 if (t1 != t2) {
1436 // Not the same entry type so there is nothing else to check. Note
1437 // that this style of checking will consider resolved/unresolved
1438 // class pairs as different.
1439 // From the ConstantPool* API point of view, this is correct
1440 // behavior. See VM_RedefineClasses::merge_constant_pools() to see how this
1441 // plays out in the context of ConstantPool* merging.
1442 return false;
1443 }
1444
1445 switch (t1) {
1446 case JVM_CONSTANT_ClassIndex:
1447 {
1448 int recur1 = klass_index_at(index1);
1449 int recur2 = cp2->klass_index_at(index2);
1450 if (compare_entry_to(recur1, cp2, recur2)) {
1451 return true;
1452 }
1453 } break;
1454
1455 case JVM_CONSTANT_Double:
1456 {
1457 jdouble d1 = double_at(index1);
1458 jdouble d2 = cp2->double_at(index2);
1459 if (d1 == d2) {
1460 return true;
1461 }
1462 } break;
1463
1464 case JVM_CONSTANT_Fieldref:
1465 case JVM_CONSTANT_InterfaceMethodref:
1466 case JVM_CONSTANT_Methodref:
1467 {
1468 int recur1 = uncached_klass_ref_index_at(index1);
1469 int recur2 = cp2->uncached_klass_ref_index_at(index2);
1470 bool match = compare_entry_to(recur1, cp2, recur2);
1471 if (match) {
1472 recur1 = uncached_name_and_type_ref_index_at(index1);
1473 recur2 = cp2->uncached_name_and_type_ref_index_at(index2);
1474 if (compare_entry_to(recur1, cp2, recur2)) {
1475 return true;
1476 }
1477 }
1478 } break;
1479
1480 case JVM_CONSTANT_Float:
1481 {
1482 jfloat f1 = float_at(index1);
1483 jfloat f2 = cp2->float_at(index2);
1484 if (f1 == f2) {
1485 return true;
1486 }
1487 } break;
1488
1489 case JVM_CONSTANT_Integer:
1490 {
1491 jint i1 = int_at(index1);
1492 jint i2 = cp2->int_at(index2);
1493 if (i1 == i2) {
1494 return true;
1495 }
1496 } break;
1497
1498 case JVM_CONSTANT_Long:
1499 {
1500 jlong l1 = long_at(index1);
1501 jlong l2 = cp2->long_at(index2);
1502 if (l1 == l2) {
1503 return true;
1504 }
1505 } break;
1506
1507 case JVM_CONSTANT_NameAndType:
1508 {
1509 int recur1 = name_ref_index_at(index1);
1510 int recur2 = cp2->name_ref_index_at(index2);
1511 if (compare_entry_to(recur1, cp2, recur2)) {
1512 recur1 = signature_ref_index_at(index1);
1513 recur2 = cp2->signature_ref_index_at(index2);
1514 if (compare_entry_to(recur1, cp2, recur2)) {
1515 return true;
1516 }
1517 }
1518 } break;
1519
1520 case JVM_CONSTANT_StringIndex:
1521 {
1522 int recur1 = string_index_at(index1);
1523 int recur2 = cp2->string_index_at(index2);
1524 if (compare_entry_to(recur1, cp2, recur2)) {
1525 return true;
1526 }
1527 } break;
1528
1529 case JVM_CONSTANT_UnresolvedClass:
1530 {
1531 Symbol* k1 = klass_name_at(index1);
1532 Symbol* k2 = cp2->klass_name_at(index2);
1533 if (k1 == k2) {
1534 return true;
1535 }
1536 } break;
1537
1538 case JVM_CONSTANT_MethodType:
1539 {
1540 int k1 = method_type_index_at(index1);
1541 int k2 = cp2->method_type_index_at(index2);
1542 if (compare_entry_to(k1, cp2, k2)) {
1543 return true;
1544 }
1545 } break;
1546
1547 case JVM_CONSTANT_MethodHandle:
1548 {
1549 int k1 = method_handle_ref_kind_at(index1);
1550 int k2 = cp2->method_handle_ref_kind_at(index2);
1551 if (k1 == k2) {
1552 int i1 = method_handle_index_at(index1);
1553 int i2 = cp2->method_handle_index_at(index2);
1554 if (compare_entry_to(i1, cp2, i2)) {
1555 return true;
1556 }
1557 }
1558 } break;
1559
1560 case JVM_CONSTANT_Dynamic:
1561 {
1562 int k1 = bootstrap_name_and_type_ref_index_at(index1);
1563 int k2 = cp2->bootstrap_name_and_type_ref_index_at(index2);
1564 int i1 = bootstrap_methods_attribute_index(index1);
1565 int i2 = cp2->bootstrap_methods_attribute_index(index2);
1566 bool match_entry = compare_entry_to(k1, cp2, k2);
1567 bool match_bsm = compare_bootstrap_entry_to(i1, cp2, i2);
1568 return (match_entry && match_bsm);
1569 } break;
1570
1571 case JVM_CONSTANT_InvokeDynamic:
1572 {
1573 int k1 = bootstrap_name_and_type_ref_index_at(index1);
1574 int k2 = cp2->bootstrap_name_and_type_ref_index_at(index2);
1575 int i1 = bootstrap_methods_attribute_index(index1);
1576 int i2 = cp2->bootstrap_methods_attribute_index(index2);
1577 bool match_entry = compare_entry_to(k1, cp2, k2);
1578 bool match_bsm = compare_bootstrap_entry_to(i1, cp2, i2);
1579 return (match_entry && match_bsm);
1580 } break;
1581
1582 case JVM_CONSTANT_String:
1583 {
1584 Symbol* s1 = unresolved_string_at(index1);
1585 Symbol* s2 = cp2->unresolved_string_at(index2);
1586 if (s1 == s2) {
1587 return true;
1588 }
1589 } break;
1590
1591 case JVM_CONSTANT_Utf8:
1592 {
1593 Symbol* s1 = symbol_at(index1);
1594 Symbol* s2 = cp2->symbol_at(index2);
1595 if (s1 == s2) {
1596 return true;
1597 }
1598 } break;
1599
1600 // Invalid is used as the tag for the second constant pool entry
1601 // occupied by JVM_CONSTANT_Double or JVM_CONSTANT_Long. It should
1602 // not be seen by itself.
1603 case JVM_CONSTANT_Invalid: // fall through
1604
1605 default:
1606 ShouldNotReachHere();
1607 break;
1608 }
1609
1610 return false;
1611 } // end compare_entry_to()
1612
1613 // Extend the BSMAttributeEntries with the length and size of the ext_cp BSMAttributeEntries.
1614 // Used in RedefineClasses for CP merge.
1615 BSMAttributeEntries::InsertionIterator
1616 ConstantPool::start_extension(const constantPoolHandle& ext_cp, TRAPS) {
1617 BSMAttributeEntries::InsertionIterator iter =
1618 bsm_entries().start_extension(ext_cp->bsm_entries(), pool_holder()->class_loader_data(),
1619 CHECK_(BSMAttributeEntries::InsertionIterator()));
1620 return iter;
1621 }
1622
1623
1624 void ConstantPool::end_extension(BSMAttributeEntries::InsertionIterator iter, TRAPS) {
1625 bsm_entries().end_extension(iter, pool_holder()->class_loader_data(), THREAD);
1626 }
1627
1628
1629 void ConstantPool::copy_bsm_entries(const constantPoolHandle& from_cp,
1630 const constantPoolHandle& to_cp,
1631 TRAPS) {
1632 to_cp->bsm_entries().append(from_cp->bsm_entries(),
1633 to_cp->pool_holder()->class_loader_data(),
1634 THREAD);
1635 }
1636
1637
1638 // Copy this constant pool's entries at start_i to end_i (inclusive)
1639 // to the constant pool to_cp's entries starting at to_i. A total of
1640 // (end_i - start_i) + 1 entries are copied.
1641 void ConstantPool::copy_cp_to_impl(const constantPoolHandle& from_cp, int start_i, int end_i,
1642 const constantPoolHandle& to_cp, int to_i, TRAPS) {
1643
1644
1645 int dest_cpi = to_i; // leave original alone for debug purposes
1646
1647 for (int src_cpi = start_i; src_cpi <= end_i; /* see loop bottom */ ) {
1648 copy_entry_to(from_cp, src_cpi, to_cp, dest_cpi);
1649
1650 switch (from_cp->tag_at(src_cpi).value()) {
1651 case JVM_CONSTANT_Double:
1652 case JVM_CONSTANT_Long:
1653 // double and long take two constant pool entries
1654 src_cpi += 2;
1655 dest_cpi += 2;
1656 break;
1657
1658 default:
1659 // all others take one constant pool entry
1660 src_cpi++;
1661 dest_cpi++;
1662 break;
1663 }
1664 }
1665 copy_bsm_entries(from_cp, to_cp, THREAD);
1666
1667 } // end copy_cp_to_impl()
1668
1669
1670 // Copy this constant pool's entry at from_i to the constant pool
1671 // to_cp's entry at to_i.
1672 void ConstantPool::copy_entry_to(const constantPoolHandle& from_cp, int from_i,
1673 const constantPoolHandle& to_cp, int to_i) {
1674
1675 int tag = from_cp->tag_at(from_i).value();
1676 switch (tag) {
1677 case JVM_CONSTANT_ClassIndex:
1678 {
1679 jint ki = from_cp->klass_index_at(from_i);
1680 to_cp->klass_index_at_put(to_i, ki);
1681 } break;
1682
1683 case JVM_CONSTANT_Double:
1684 {
1685 jdouble d = from_cp->double_at(from_i);
1686 to_cp->double_at_put(to_i, d);
1687 // double takes two constant pool entries so init second entry's tag
1688 to_cp->tag_at_put(to_i + 1, JVM_CONSTANT_Invalid);
1689 } break;
1690
1691 case JVM_CONSTANT_Fieldref:
1692 {
1693 int class_index = from_cp->uncached_klass_ref_index_at(from_i);
1694 int name_and_type_index = from_cp->uncached_name_and_type_ref_index_at(from_i);
1695 to_cp->field_at_put(to_i, class_index, name_and_type_index);
1696 } break;
1697
1698 case JVM_CONSTANT_Float:
1699 {
1700 jfloat f = from_cp->float_at(from_i);
1701 to_cp->float_at_put(to_i, f);
1702 } break;
1703
1704 case JVM_CONSTANT_Integer:
1705 {
1706 jint i = from_cp->int_at(from_i);
1707 to_cp->int_at_put(to_i, i);
1708 } break;
1709
1710 case JVM_CONSTANT_InterfaceMethodref:
1711 {
1712 int class_index = from_cp->uncached_klass_ref_index_at(from_i);
1713 int name_and_type_index = from_cp->uncached_name_and_type_ref_index_at(from_i);
1714 to_cp->interface_method_at_put(to_i, class_index, name_and_type_index);
1715 } break;
1716
1717 case JVM_CONSTANT_Long:
1718 {
1719 jlong l = from_cp->long_at(from_i);
1720 to_cp->long_at_put(to_i, l);
1721 // long takes two constant pool entries so init second entry's tag
1722 to_cp->tag_at_put(to_i + 1, JVM_CONSTANT_Invalid);
1723 } break;
1724
1725 case JVM_CONSTANT_Methodref:
1726 {
1727 int class_index = from_cp->uncached_klass_ref_index_at(from_i);
1728 int name_and_type_index = from_cp->uncached_name_and_type_ref_index_at(from_i);
1729 to_cp->method_at_put(to_i, class_index, name_and_type_index);
1730 } break;
1731
1732 case JVM_CONSTANT_NameAndType:
1733 {
1734 int name_ref_index = from_cp->name_ref_index_at(from_i);
1735 int signature_ref_index = from_cp->signature_ref_index_at(from_i);
1736 to_cp->name_and_type_at_put(to_i, name_ref_index, signature_ref_index);
1737 } break;
1738
1739 case JVM_CONSTANT_StringIndex:
1740 {
1741 jint si = from_cp->string_index_at(from_i);
1742 to_cp->string_index_at_put(to_i, si);
1743 } break;
1744
1745 case JVM_CONSTANT_Class:
1746 case JVM_CONSTANT_UnresolvedClass:
1747 case JVM_CONSTANT_UnresolvedClassInError:
1748 {
1749 // Revert to JVM_CONSTANT_ClassIndex
1750 int name_index = from_cp->klass_slot_at(from_i).name_index();
1751 assert(from_cp->tag_at(name_index).is_symbol(), "sanity");
1752 to_cp->klass_index_at_put(to_i, name_index);
1753 } break;
1754
1755 case JVM_CONSTANT_String:
1756 {
1757 Symbol* s = from_cp->unresolved_string_at(from_i);
1758 to_cp->unresolved_string_at_put(to_i, s);
1759 } break;
1760
1761 case JVM_CONSTANT_Utf8:
1762 {
1763 Symbol* s = from_cp->symbol_at(from_i);
1764 // Need to increase refcount, the old one will be thrown away and deferenced
1765 s->increment_refcount();
1766 to_cp->symbol_at_put(to_i, s);
1767 } break;
1768
1769 case JVM_CONSTANT_MethodType:
1770 case JVM_CONSTANT_MethodTypeInError:
1771 {
1772 jint k = from_cp->method_type_index_at(from_i);
1773 to_cp->method_type_index_at_put(to_i, k);
1774 } break;
1775
1776 case JVM_CONSTANT_MethodHandle:
1777 case JVM_CONSTANT_MethodHandleInError:
1778 {
1779 int k1 = from_cp->method_handle_ref_kind_at(from_i);
1780 int k2 = from_cp->method_handle_index_at(from_i);
1781 to_cp->method_handle_index_at_put(to_i, k1, k2);
1782 } break;
1783
1784 case JVM_CONSTANT_Dynamic:
1785 case JVM_CONSTANT_DynamicInError:
1786 {
1787 int k1 = from_cp->bootstrap_methods_attribute_index(from_i);
1788 int k2 = from_cp->bootstrap_name_and_type_ref_index_at(from_i);
1789 k1 += to_cp->bsm_entries().array_length(); // to_cp might already have a BSM attribute
1790 to_cp->dynamic_constant_at_put(to_i, k1, k2);
1791 } break;
1792
1793 case JVM_CONSTANT_InvokeDynamic:
1794 {
1795 int k1 = from_cp->bootstrap_methods_attribute_index(from_i);
1796 int k2 = from_cp->bootstrap_name_and_type_ref_index_at(from_i);
1797 k1 += to_cp->bsm_entries().array_length(); // to_cp might already have a BSM attribute
1798 to_cp->invoke_dynamic_at_put(to_i, k1, k2);
1799 } break;
1800
1801 // Invalid is used as the tag for the second constant pool entry
1802 // occupied by JVM_CONSTANT_Double or JVM_CONSTANT_Long. It should
1803 // not be seen by itself.
1804 case JVM_CONSTANT_Invalid: // fall through
1805
1806 default:
1807 {
1808 ShouldNotReachHere();
1809 } break;
1810 }
1811 } // end copy_entry_to()
1812
1813 // Search constant pool search_cp for an entry that matches this
1814 // constant pool's entry at pattern_i. Returns the index of a
1815 // matching entry or zero (0) if there is no matching entry.
1816 int ConstantPool::find_matching_entry(int pattern_i,
1817 const constantPoolHandle& search_cp) {
1818
1819 // index zero (0) is not used
1820 for (int i = 1; i < search_cp->length(); i++) {
1821 bool found = compare_entry_to(pattern_i, search_cp, i);
1822 if (found) {
1823 return i;
1824 }
1825 }
1826
1827 return 0; // entry not found; return unused index zero (0)
1828 } // end find_matching_entry()
1829
1830
1831 // Compare this constant pool's bootstrap specifier at idx1 to the constant pool
1832 // cp2's bootstrap specifier at idx2.
1833 bool ConstantPool::compare_bootstrap_entry_to(int idx1, const constantPoolHandle& cp2, int idx2) {
1834 const BSMAttributeEntry* const e1 = bsm_attribute_entry(idx1);
1835 const BSMAttributeEntry* const e2 = cp2->bsm_attribute_entry(idx2);
1836 int k1 = e1->bootstrap_method_index();
1837 int k2 = e2->bootstrap_method_index();
1838 bool match = compare_entry_to(k1, cp2, k2);
1839
1840 if (!match) {
1841 return false;
1842 }
1843
1844 const int argc = e1->argument_count();
1845 if (argc != e2->argument_count()) {
1846 return false;
1847 }
1848
1849 for (int j = 0; j < argc; j++) {
1850 k1 = e1->argument(j);
1851 k2 = e2->argument(j);
1852 match = compare_entry_to(k1, cp2, k2);
1853 if (!match) {
1854 return false;
1855 }
1856 }
1857
1858 return true; // got through loop; all elements equal
1859 } // end compare_bootstrap_entry_to()
1860
1861 // Search constant pool search_cp for a bootstrap specifier that matches
1862 // this constant pool's bootstrap specifier data at pattern_i index.
1863 // Return the index of a matching bootstrap attribute record or (-1) if there is no match.
1864 int ConstantPool::find_matching_bsm_entry(int pattern_i,
1865 const constantPoolHandle& search_cp, int offset_limit) {
1866 for (int i = 0; i < offset_limit; i++) {
1867 bool found = compare_bootstrap_entry_to(pattern_i, search_cp, i);
1868 if (found) {
1869 return i;
1870 }
1871 }
1872 return -1; // bootstrap specifier data not found; return unused index (-1)
1873 } // end find_matching_bsm_entry()
1874
1875
1876 #ifndef PRODUCT
1877
1878 const char* ConstantPool::printable_name_at(int cp_index) {
1879
1880 constantTag tag = tag_at(cp_index);
1881
1882 if (tag.is_string()) {
1883 return string_at_noresolve(cp_index);
1884 } else if (tag.is_klass() || tag.is_unresolved_klass()) {
1885 return klass_name_at(cp_index)->as_C_string();
1886 } else if (tag.is_symbol()) {
1887 return symbol_at(cp_index)->as_C_string();
1888 }
1889 return "";
1890 }
1891
1892 #endif // PRODUCT
1893
1894
1895 // Returns size of constant pool entry.
1896 jint ConstantPool::cpool_entry_size(jint idx) {
1897 switch(tag_at(idx).value()) {
1898 case JVM_CONSTANT_Invalid:
1899 case JVM_CONSTANT_Unicode:
1900 return 1;
1901
1902 case JVM_CONSTANT_Utf8:
1903 return 3 + symbol_at(idx)->utf8_length();
1904
1905 case JVM_CONSTANT_Class:
1906 case JVM_CONSTANT_String:
1907 case JVM_CONSTANT_ClassIndex:
1908 case JVM_CONSTANT_UnresolvedClass:
1909 case JVM_CONSTANT_UnresolvedClassInError:
1910 case JVM_CONSTANT_StringIndex:
1911 case JVM_CONSTANT_MethodType:
1912 case JVM_CONSTANT_MethodTypeInError:
1913 return 3;
1914
1915 case JVM_CONSTANT_MethodHandle:
1916 case JVM_CONSTANT_MethodHandleInError:
1917 return 4; //tag, ref_kind, ref_index
1918
1919 case JVM_CONSTANT_Integer:
1920 case JVM_CONSTANT_Float:
1921 case JVM_CONSTANT_Fieldref:
1922 case JVM_CONSTANT_Methodref:
1923 case JVM_CONSTANT_InterfaceMethodref:
1924 case JVM_CONSTANT_NameAndType:
1925 return 5;
1926
1927 case JVM_CONSTANT_Dynamic:
1928 case JVM_CONSTANT_DynamicInError:
1929 case JVM_CONSTANT_InvokeDynamic:
1930 // u1 tag, u2 bsm, u2 nt
1931 return 5;
1932
1933 case JVM_CONSTANT_Long:
1934 case JVM_CONSTANT_Double:
1935 return 9;
1936 }
1937 assert(false, "cpool_entry_size: Invalid constant pool entry tag");
1938 return 1;
1939 } /* end cpool_entry_size */
1940
1941
1942 // SymbolHash is used to find a constant pool index from a string.
1943 // This function fills in SymbolHashs, one for utf8s and one for
1944 // class names, returns size of the cpool raw bytes.
1945 jint ConstantPool::hash_entries_to(SymbolHash *symmap,
1946 SymbolHash *classmap) {
1947 jint size = 0;
1948
1949 for (u2 idx = 1; idx < length(); idx++) {
1950 u2 tag = tag_at(idx).value();
1951 size += cpool_entry_size(idx);
1952
1953 switch(tag) {
1954 case JVM_CONSTANT_Utf8: {
1955 Symbol* sym = symbol_at(idx);
1956 symmap->add_if_absent(sym, idx);
1957 break;
1958 }
1959 case JVM_CONSTANT_Class:
1960 case JVM_CONSTANT_UnresolvedClass:
1961 case JVM_CONSTANT_UnresolvedClassInError: {
1962 Symbol* sym = klass_name_at(idx);
1963 classmap->add_if_absent(sym, idx);
1964 break;
1965 }
1966 case JVM_CONSTANT_Long:
1967 case JVM_CONSTANT_Double: {
1968 idx++; // Both Long and Double take two cpool slots
1969 break;
1970 }
1971 }
1972 }
1973 return size;
1974 } /* end hash_utf8_entries_to */
1975
1976
1977 // Copy cpool bytes.
1978 // Returns:
1979 // 0, in case of OutOfMemoryError
1980 // -1, in case of internal error
1981 // > 0, count of the raw cpool bytes that have been copied
1982 int ConstantPool::copy_cpool_bytes(int cpool_size,
1983 SymbolHash* tbl,
1984 unsigned char *bytes) {
1985 u2 idx1, idx2;
1986 jint size = 0;
1987 jint cnt = length();
1988 unsigned char *start_bytes = bytes;
1989
1990 for (jint idx = 1; idx < cnt; idx++) {
1991 u1 tag = tag_at(idx).value();
1992 jint ent_size = cpool_entry_size(idx);
1993
1994 assert(size + ent_size <= cpool_size, "Size mismatch");
1995
1996 *bytes = tag;
1997 switch(tag) {
1998 case JVM_CONSTANT_Invalid: {
1999 break;
2000 }
2001 case JVM_CONSTANT_Unicode: {
2002 assert(false, "Wrong constant pool tag: JVM_CONSTANT_Unicode");
2003 break;
2004 }
2005 case JVM_CONSTANT_Utf8: {
2006 Symbol* sym = symbol_at(idx);
2007 char* str = sym->as_utf8();
2008 // Warning! It's crashing on x86 with len = sym->utf8_length()
2009 int len = (int) strlen(str);
2010 Bytes::put_Java_u2((address) (bytes+1), (u2) len);
2011 for (int i = 0; i < len; i++) {
2012 bytes[3+i] = (u1) str[i];
2013 }
2014 break;
2015 }
2016 case JVM_CONSTANT_Integer: {
2017 jint val = int_at(idx);
2018 Bytes::put_Java_u4((address) (bytes+1), *(u4*)&val);
2019 break;
2020 }
2021 case JVM_CONSTANT_Float: {
2022 jfloat val = float_at(idx);
2023 Bytes::put_Java_u4((address) (bytes+1), *(u4*)&val);
2024 break;
2025 }
2026 case JVM_CONSTANT_Long: {
2027 jlong val = long_at(idx);
2028 Bytes::put_Java_u8((address) (bytes+1), *(u8*)&val);
2029 idx++; // Long takes two cpool slots
2030 break;
2031 }
2032 case JVM_CONSTANT_Double: {
2033 jdouble val = double_at(idx);
2034 Bytes::put_Java_u8((address) (bytes+1), *(u8*)&val);
2035 idx++; // Double takes two cpool slots
2036 break;
2037 }
2038 case JVM_CONSTANT_Class:
2039 case JVM_CONSTANT_UnresolvedClass:
2040 case JVM_CONSTANT_UnresolvedClassInError: {
2041 *bytes = JVM_CONSTANT_Class;
2042 Symbol* sym = klass_name_at(idx);
2043 idx1 = tbl->symbol_to_value(sym);
2044 assert(idx1 != 0, "Have not found a hashtable entry");
2045 Bytes::put_Java_u2((address) (bytes+1), idx1);
2046 break;
2047 }
2048 case JVM_CONSTANT_String: {
2049 *bytes = JVM_CONSTANT_String;
2050 Symbol* sym = unresolved_string_at(idx);
2051 idx1 = tbl->symbol_to_value(sym);
2052 assert(idx1 != 0, "Have not found a hashtable entry");
2053 Bytes::put_Java_u2((address) (bytes+1), idx1);
2054 break;
2055 }
2056 case JVM_CONSTANT_Fieldref:
2057 case JVM_CONSTANT_Methodref:
2058 case JVM_CONSTANT_InterfaceMethodref: {
2059 idx1 = uncached_klass_ref_index_at(idx);
2060 idx2 = uncached_name_and_type_ref_index_at(idx);
2061 Bytes::put_Java_u2((address) (bytes+1), idx1);
2062 Bytes::put_Java_u2((address) (bytes+3), idx2);
2063 break;
2064 }
2065 case JVM_CONSTANT_NameAndType: {
2066 idx1 = name_ref_index_at(idx);
2067 idx2 = signature_ref_index_at(idx);
2068 Bytes::put_Java_u2((address) (bytes+1), idx1);
2069 Bytes::put_Java_u2((address) (bytes+3), idx2);
2070 break;
2071 }
2072 case JVM_CONSTANT_ClassIndex: {
2073 *bytes = JVM_CONSTANT_Class;
2074 idx1 = checked_cast<u2>(klass_index_at(idx));
2075 Bytes::put_Java_u2((address) (bytes+1), idx1);
2076 break;
2077 }
2078 case JVM_CONSTANT_StringIndex: {
2079 *bytes = JVM_CONSTANT_String;
2080 idx1 = checked_cast<u2>(string_index_at(idx));
2081 Bytes::put_Java_u2((address) (bytes+1), idx1);
2082 break;
2083 }
2084 case JVM_CONSTANT_MethodHandle:
2085 case JVM_CONSTANT_MethodHandleInError: {
2086 *bytes = JVM_CONSTANT_MethodHandle;
2087 int kind = method_handle_ref_kind_at(idx);
2088 idx1 = checked_cast<u2>(method_handle_index_at(idx));
2089 *(bytes+1) = (unsigned char) kind;
2090 Bytes::put_Java_u2((address) (bytes+2), idx1);
2091 break;
2092 }
2093 case JVM_CONSTANT_MethodType:
2094 case JVM_CONSTANT_MethodTypeInError: {
2095 *bytes = JVM_CONSTANT_MethodType;
2096 idx1 = checked_cast<u2>(method_type_index_at(idx));
2097 Bytes::put_Java_u2((address) (bytes+1), idx1);
2098 break;
2099 }
2100 case JVM_CONSTANT_Dynamic:
2101 case JVM_CONSTANT_DynamicInError: {
2102 *bytes = tag;
2103 idx1 = extract_low_short_from_int(*int_at_addr(idx));
2104 idx2 = extract_high_short_from_int(*int_at_addr(idx));
2105 assert(idx2 == bootstrap_name_and_type_ref_index_at(idx), "correct half of u4");
2106 Bytes::put_Java_u2((address) (bytes+1), idx1);
2107 Bytes::put_Java_u2((address) (bytes+3), idx2);
2108 break;
2109 }
2110 case JVM_CONSTANT_InvokeDynamic: {
2111 *bytes = tag;
2112 idx1 = extract_low_short_from_int(*int_at_addr(idx));
2113 idx2 = extract_high_short_from_int(*int_at_addr(idx));
2114 assert(idx2 == bootstrap_name_and_type_ref_index_at(idx), "correct half of u4");
2115 Bytes::put_Java_u2((address) (bytes+1), idx1);
2116 Bytes::put_Java_u2((address) (bytes+3), idx2);
2117 break;
2118 }
2119 }
2120 bytes += ent_size;
2121 size += ent_size;
2122 }
2123 assert(size == cpool_size, "Size mismatch");
2124
2125 return (int)(bytes - start_bytes);
2126 } /* end copy_cpool_bytes */
2127
2128 bool ConstantPool::is_maybe_on_stack() const {
2129 // This method uses the similar logic as nmethod::is_maybe_on_stack()
2130 if (!Continuations::enabled()) {
2131 return false;
2132 }
2133
2134 // If the condition below is true, it means that the nmethod was found to
2135 // be alive the previous completed marking cycle.
2136 return cache()->gc_epoch() >= CodeCache::previous_completed_gc_marking_cycle();
2137 }
2138
2139 // For redefinition, if any methods found in loom stack chunks, the gc_epoch is
2140 // recorded in their constant pool cache. The on_stack-ness of the constant pool controls whether
2141 // memory for the method is reclaimed.
2142 bool ConstantPool::on_stack() const {
2143 if ((_flags &_on_stack) != 0) {
2144 return true;
2145 }
2146
2147 if (_cache == nullptr) {
2148 return false;
2149 }
2150
2151 return is_maybe_on_stack();
2152 }
2153
2154 void ConstantPool::set_on_stack(const bool value) {
2155 if (value) {
2156 // Only record if it's not already set.
2157 if (!on_stack()) {
2158 assert(!in_aot_cache(), "should always be set for constant pools in AOT cache");
2159 _flags |= _on_stack;
2160 MetadataOnStackMark::record(this);
2161 }
2162 } else {
2163 // Clearing is done single-threadedly.
2164 if (!in_aot_cache()) {
2165 _flags &= (u2)(~_on_stack);
2166 }
2167 }
2168 }
2169
2170 // Printing
2171
2172 void ConstantPool::print_on(outputStream* st) const {
2173 assert(is_constantPool(), "must be constantPool");
2174 st->print_cr("%s", internal_name());
2175 if (flags() != 0) {
2176 st->print(" - flags: 0x%x", flags());
2177 if (has_preresolution()) st->print(" has_preresolution");
2178 if (on_stack()) st->print(" on_stack");
2179 st->cr();
2180 }
2181 if (pool_holder() != nullptr) {
2182 st->print_cr(" - holder: " PTR_FORMAT, p2i(pool_holder()));
2183 }
2184 st->print_cr(" - cache: " PTR_FORMAT, p2i(cache()));
2185 st->print_cr(" - resolved_references: " PTR_FORMAT, p2i(resolved_references_or_null()));
2186 st->print_cr(" - reference_map: " PTR_FORMAT, p2i(reference_map()));
2187 st->print_cr(" - resolved_klasses: " PTR_FORMAT, p2i(resolved_klasses()));
2188 st->print_cr(" - cp length: %d", length());
2189
2190 for (int index = 1; index < length(); index++) { // Index 0 is unused
2191 ((ConstantPool*)this)->print_entry_on(index, st);
2192 switch (tag_at(index).value()) {
2193 case JVM_CONSTANT_Long :
2194 case JVM_CONSTANT_Double :
2195 index++; // Skip entry following eigth-byte constant
2196 }
2197
2198 }
2199 st->cr();
2200 }
2201
2202 // Print one constant pool entry
2203 void ConstantPool::print_entry_on(const int cp_index, outputStream* st) {
2204 EXCEPTION_MARK;
2205 st->print(" - %3d : ", cp_index);
2206 tag_at(cp_index).print_on(st);
2207 st->print(" : ");
2208 switch (tag_at(cp_index).value()) {
2209 case JVM_CONSTANT_Class :
2210 { Klass* k = klass_at(cp_index, CATCH);
2211 guarantee(k != nullptr, "need klass");
2212 k->print_value_on(st);
2213 st->print(" {" PTR_FORMAT "}", p2i(k));
2214 }
2215 break;
2216 case JVM_CONSTANT_Fieldref :
2217 case JVM_CONSTANT_Methodref :
2218 case JVM_CONSTANT_InterfaceMethodref :
2219 st->print("klass_index=%d", uncached_klass_ref_index_at(cp_index));
2220 st->print(" name_and_type_index=%d", uncached_name_and_type_ref_index_at(cp_index));
2221 break;
2222 case JVM_CONSTANT_String :
2223 unresolved_string_at(cp_index)->print_value_on(st);
2224 break;
2225 case JVM_CONSTANT_Integer :
2226 st->print("%d", int_at(cp_index));
2227 break;
2228 case JVM_CONSTANT_Float :
2229 st->print("%f", float_at(cp_index));
2230 break;
2231 case JVM_CONSTANT_Long :
2232 st->print_jlong(long_at(cp_index));
2233 break;
2234 case JVM_CONSTANT_Double :
2235 st->print("%lf", double_at(cp_index));
2236 break;
2237 case JVM_CONSTANT_NameAndType :
2238 st->print("name_index=%d", name_ref_index_at(cp_index));
2239 st->print(" signature_index=%d", signature_ref_index_at(cp_index));
2240 break;
2241 case JVM_CONSTANT_Utf8 :
2242 symbol_at(cp_index)->print_value_on(st);
2243 break;
2244 case JVM_CONSTANT_ClassIndex: {
2245 int name_index = *int_at_addr(cp_index);
2246 st->print("klass_index=%d ", name_index);
2247 symbol_at(name_index)->print_value_on(st);
2248 }
2249 break;
2250 case JVM_CONSTANT_UnresolvedClass : // fall-through
2251 case JVM_CONSTANT_UnresolvedClassInError: {
2252 CPKlassSlot kslot = klass_slot_at(cp_index);
2253 int resolved_klass_index = kslot.resolved_klass_index();
2254 int name_index = kslot.name_index();
2255 assert(tag_at(name_index).is_symbol(), "sanity");
2256 symbol_at(name_index)->print_value_on(st);
2257 }
2258 break;
2259 case JVM_CONSTANT_MethodHandle :
2260 case JVM_CONSTANT_MethodHandleInError :
2261 st->print("ref_kind=%d", method_handle_ref_kind_at(cp_index));
2262 st->print(" ref_index=%d", method_handle_index_at(cp_index));
2263 break;
2264 case JVM_CONSTANT_MethodType :
2265 case JVM_CONSTANT_MethodTypeInError :
2266 st->print("signature_index=%d", method_type_index_at(cp_index));
2267 break;
2268 case JVM_CONSTANT_Dynamic :
2269 case JVM_CONSTANT_DynamicInError :
2270 {
2271 st->print("bootstrap_method_index=%d", bootstrap_method_ref_index_at(cp_index));
2272 st->print(" type_index=%d", bootstrap_name_and_type_ref_index_at(cp_index));
2273 int argc = bootstrap_argument_count_at(cp_index);
2274 if (argc > 0) {
2275 for (int arg_i = 0; arg_i < argc; arg_i++) {
2276 int arg = bootstrap_argument_index_at(cp_index, arg_i);
2277 st->print((arg_i == 0 ? " arguments={%d" : ", %d"), arg);
2278 }
2279 st->print("}");
2280 }
2281 }
2282 break;
2283 case JVM_CONSTANT_InvokeDynamic :
2284 {
2285 st->print("bootstrap_method_index=%d", bootstrap_method_ref_index_at(cp_index));
2286 st->print(" name_and_type_index=%d", bootstrap_name_and_type_ref_index_at(cp_index));
2287 int argc = bootstrap_argument_count_at(cp_index);
2288 if (argc > 0) {
2289 for (int arg_i = 0; arg_i < argc; arg_i++) {
2290 int arg = bootstrap_argument_index_at(cp_index, arg_i);
2291 st->print((arg_i == 0 ? " arguments={%d" : ", %d"), arg);
2292 }
2293 st->print("}");
2294 }
2295 }
2296 break;
2297 default:
2298 ShouldNotReachHere();
2299 break;
2300 }
2301 st->cr();
2302 }
2303
2304 void ConstantPool::print_value_on(outputStream* st) const {
2305 assert(is_constantPool(), "must be constantPool");
2306 st->print("constant pool [%d]", length());
2307 if (has_preresolution()) st->print("/preresolution");
2308 if (!bsm_entries().is_empty()) st->print("/BSMs[%d]", bsm_entries().bootstrap_methods()->length());
2309 print_address_on(st);
2310 if (pool_holder() != nullptr) {
2311 st->print(" for ");
2312 pool_holder()->print_value_on(st);
2313 bool extra = (pool_holder()->constants() != this);
2314 if (extra) st->print(" (extra)");
2315 }
2316 if (cache() != nullptr) {
2317 st->print(" cache=" PTR_FORMAT, p2i(cache()));
2318 }
2319 }
2320
2321 // Verification
2322
2323 void ConstantPool::verify_on(outputStream* st) {
2324 guarantee(is_constantPool(), "object must be constant pool");
2325 for (int i = 0; i< length(); i++) {
2326 constantTag tag = tag_at(i);
2327 if (tag.is_klass() || tag.is_unresolved_klass()) {
2328 guarantee(klass_name_at(i)->refcount() != 0, "should have nonzero reference count");
2329 } else if (tag.is_symbol()) {
2330 Symbol* entry = symbol_at(i);
2331 guarantee(entry->refcount() != 0, "should have nonzero reference count");
2332 } else if (tag.is_string()) {
2333 Symbol* entry = unresolved_string_at(i);
2334 guarantee(entry->refcount() != 0, "should have nonzero reference count");
2335 }
2336 }
2337 if (pool_holder() != nullptr) {
2338 // Note: pool_holder() can be null in temporary constant pools
2339 // used during constant pool merging
2340 guarantee(pool_holder()->is_klass(), "should be klass");
2341 }
2342 }
2343
2344 void BSMAttributeEntries::deallocate_contents(ClassLoaderData* loader_data) {
2345 MetadataFactory::free_array<u4>(loader_data, this->_offsets);
2346 MetadataFactory::free_array<u2>(loader_data, this->_bootstrap_methods);
2347 this->_offsets = nullptr;
2348 this->_bootstrap_methods = nullptr;
2349 }
2350
2351 void BSMAttributeEntries::copy_into(InsertionIterator& iter, int num_entries) const {
2352 assert(num_entries + iter._cur_offset <= iter._insert_into->_offsets->length(), "must");
2353 for (int i = 0; i < num_entries; i++) {
2354 const BSMAttributeEntry* e = entry(i);
2355 BSMAttributeEntry* e_new = iter.reserve_new_entry(e->bootstrap_method_index(), e->argument_count());
2356 assert(e_new != nullptr, "must be");
2357 e->copy_args_into(e_new);
2358 }
2359 }
2360
2361 BSMAttributeEntries::InsertionIterator
2362 BSMAttributeEntries::start_extension(const BSMAttributeEntries& other, ClassLoaderData* loader_data, TRAPS) {
2363 InsertionIterator iter = start_extension(other.number_of_entries(), other.array_length(),
2364 loader_data, CHECK_(BSMAttributeEntries::InsertionIterator()));
2365 return iter;
2366 }
2367
2368 BSMAttributeEntries::InsertionIterator
2369 BSMAttributeEntries::start_extension(int number_of_entries, int array_length,
2370 ClassLoaderData* loader_data, TRAPS) {
2371 InsertionIterator extension_iterator(this, this->number_of_entries(), this->array_length());
2372 int new_number_of_entries = this->number_of_entries() + number_of_entries;
2373 int new_array_length = this->array_length() + array_length;
2374 int invalid_index = new_array_length;
2375
2376 Array<u4>* new_offsets =
2377 MetadataFactory::new_array<u4>(loader_data, new_number_of_entries, invalid_index, CHECK_(InsertionIterator()));
2378 Array<u2>* new_array = MetadataFactory::new_array<u2>(loader_data, new_array_length, CHECK_(InsertionIterator()));
2379 { // Copy over all the old BSMAEntry's and their respective offsets
2380 BSMAttributeEntries carrier(new_offsets, new_array);
2381 InsertionIterator copy_iter(&carrier, 0, 0);
2382 copy_into(copy_iter, this->number_of_entries());
2383 }
2384 // Replace content
2385 deallocate_contents(loader_data);
2386 _offsets = new_offsets;
2387 _bootstrap_methods = new_array;
2388 return extension_iterator;
2389 }
2390
2391
2392 void BSMAttributeEntries::append(const BSMAttributeEntries& other, ClassLoaderData* loader_data, TRAPS) {
2393 if (other.number_of_entries() == 0) {
2394 return; // Done!
2395 }
2396 InsertionIterator iter = start_extension(other, loader_data, CHECK);
2397 other.copy_into(iter, other.number_of_entries());
2398 end_extension(iter, loader_data, THREAD);
2399 }
2400
2401 void BSMAttributeEntries::end_extension(InsertionIterator& iter, ClassLoaderData* loader_data, TRAPS) {
2402 assert(iter._insert_into == this, "must be");
2403 assert(iter._cur_offset <= this->_offsets->length(), "must be");
2404 assert(iter._cur_array <= this->_bootstrap_methods->length(), "must be");
2405
2406 // Did we fill up all of the available space? If so, do nothing.
2407 if (iter._cur_offset == this->_offsets->length() &&
2408 iter._cur_array == this->_bootstrap_methods->length()) {
2409 return;
2410 }
2411
2412 // We used less, truncate by allocating new arrays
2413 Array<u4>* new_offsets =
2414 MetadataFactory::new_array<u4>(loader_data, iter._cur_offset, 0, CHECK);
2415 Array<u2>* new_array =
2416 MetadataFactory::new_array<u2>(loader_data, iter._cur_array, CHECK);
2417 { // Copy over the constructed BSMAEntry's
2418 BSMAttributeEntries carrier(new_offsets, new_array);
2419 InsertionIterator copy_iter(&carrier, 0, 0);
2420 copy_into(copy_iter, iter._cur_offset);
2421 }
2422
2423 deallocate_contents(loader_data);
2424 _offsets = new_offsets;
2425 _bootstrap_methods = new_array;
2426 }