1 /*
2 * Copyright (c) 1997, 2024, 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 "precompiled.hpp"
26 #include "cds/aotConstantPoolResolver.hpp"
27 #include "cds/archiveHeapWriter.hpp"
28 #include "cds/archiveHeapLoader.hpp"
29 #include "cds/archiveBuilder.hpp"
30 #include "cds/cdsConfig.hpp"
31 #include "cds/heapShared.hpp"
32 #include "classfile/classLoader.hpp"
33 #include "classfile/classLoaderData.hpp"
34 #include "classfile/javaClasses.inline.hpp"
35 #include "classfile/metadataOnStackMark.hpp"
36 #include "classfile/stringTable.hpp"
37 #include "classfile/systemDictionary.hpp"
38 #include "classfile/systemDictionaryShared.hpp"
39 #include "classfile/vmClasses.hpp"
40 #include "classfile/vmSymbols.hpp"
41 #include "code/codeCache.hpp"
42 #include "interpreter/bootstrapInfo.hpp"
43 #include "interpreter/linkResolver.hpp"
44 #include "jvm.h"
45 #include "logging/log.hpp"
46 #include "logging/logStream.hpp"
47 #include "memory/allocation.inline.hpp"
48 #include "memory/metadataFactory.hpp"
49 #include "memory/metaspaceClosure.hpp"
50 #include "memory/oopFactory.hpp"
51 #include "memory/resourceArea.hpp"
52 #include "memory/universe.hpp"
53 #include "oops/array.hpp"
54 #include "oops/constantPool.inline.hpp"
55 #include "oops/cpCache.inline.hpp"
56 #include "oops/instanceKlass.hpp"
57 #include "oops/klass.inline.hpp"
58 #include "oops/objArrayKlass.hpp"
59 #include "oops/objArrayOop.inline.hpp"
60 #include "oops/oop.inline.hpp"
61 #include "oops/typeArrayOop.inline.hpp"
62 #include "prims/jvmtiExport.hpp"
63 #include "runtime/atomic.hpp"
64 #include "runtime/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 MetadataFactory::free_array<jushort>(loader_data, operands());
136 set_operands(nullptr);
137
138 release_C_heap_structures();
139
140 // free tag array
141 MetadataFactory::free_array<u1>(loader_data, tags());
142 set_tags(nullptr);
143 }
144
145 void ConstantPool::release_C_heap_structures() {
146 // walk constant pool and decrement symbol reference counts
147 unreference_symbols();
148 }
149
150 void ConstantPool::metaspace_pointers_do(MetaspaceClosure* it) {
151 log_trace(cds)("Iter(ConstantPool): %p", this);
152
153 it->push(&_tags, MetaspaceClosure::_writable);
154 it->push(&_cache);
155 it->push(&_pool_holder);
156 it->push(&_operands);
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 Atomic::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_invokedynamic()) {
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 function(rr_index);
298 }
299 }
300 }
301
302 Array<ResolvedMethodEntry>* method_entries = cache()->resolved_method_entries();
303 if (method_entries != nullptr) {
304 for (int i = 0; i < method_entries->length(); i++) {
305 ResolvedMethodEntry* rme = method_entries->adr_at(i);
306 if (rme->is_resolved(Bytecodes::_invokehandle) && rme->has_appendix() &&
307 cache()->can_archive_resolved_method(this, rme)) {
308 int rr_index = rme->resolved_references_index();
309 function(rr_index);
310 }
311 }
312 }
313 }
314 }
315
316 // Returns the _resolved_reference array after removing unarchivable items from it.
317 // Returns null if this class is not supported, or _resolved_reference doesn't exist.
318 objArrayOop ConstantPool::prepare_resolved_references_for_archiving() {
319 if (_cache == nullptr) {
320 return nullptr; // nothing to do
321 }
322
323 InstanceKlass *ik = pool_holder();
324 if (!(ik->is_shared_boot_class() || ik->is_shared_platform_class() ||
325 ik->is_shared_app_class())) {
326 // Archiving resolved references for classes from non-builtin loaders
327 // is not yet supported.
328 return nullptr;
329 }
330
331 objArrayOop rr = resolved_references();
332 if (rr != nullptr) {
333 ResourceMark rm;
334 int rr_len = rr->length();
335 GrowableArray<bool> keep_resolved_refs(rr_len, rr_len, false);
336
337 ConstantPool* src_cp = ArchiveBuilder::current()->get_source_addr(this);
338 src_cp->iterate_archivable_resolved_references([&](int rr_index) {
339 keep_resolved_refs.at_put(rr_index, true);
340 });
341
342 objArrayOop scratch_rr = HeapShared::scratch_resolved_references(src_cp);
343 Array<u2>* ref_map = reference_map();
344 int ref_map_len = ref_map == nullptr ? 0 : ref_map->length();
345 for (int i = 0; i < rr_len; i++) {
346 oop obj = rr->obj_at(i);
347 scratch_rr->obj_at_put(i, nullptr);
348 if (obj != nullptr) {
349 if (i < ref_map_len) {
350 int index = object_to_cp_index(i);
351 if (tag_at(index).is_string()) {
352 assert(java_lang_String::is_instance(obj), "must be");
353 if (!ArchiveHeapWriter::is_string_too_large_to_archive(obj)) {
354 scratch_rr->obj_at_put(i, obj);
355 }
356 }
357 } else if (keep_resolved_refs.at(i)) {
358 scratch_rr->obj_at_put(i, obj);
359 }
360 }
361 }
362 return scratch_rr;
363 }
364 return rr;
365 }
366
367 void ConstantPool::find_archivable_hidden_classes() {
368 if (_cache == nullptr) {
369 return;
370 }
371
372 ClassLoaderData* loader_data = pool_holder()->class_loader_data();
373 if (loader_data == nullptr) {
374 // These are custom loader classes from the preimage
375 return;
376 }
377
378 if (!SystemDictionaryShared::is_builtin_loader(loader_data)) {
379 // Archiving resolved references for classes from non-builtin loaders
380 // is not yet supported.
381 return;
382 }
383
384 objArrayOop rr = resolved_references();
385 if (rr != nullptr) {
386 iterate_archivable_resolved_references([&](int rr_index) {
387 oop obj = rr->obj_at(rr_index);
388 HeapShared::find_archivable_hidden_classes_in_object(obj);
389 });
390 }
391 }
392
393 void ConstantPool::add_dumped_interned_strings() {
394 objArrayOop rr = resolved_references();
395 if (rr != nullptr) {
396 int rr_len = rr->length();
397 for (int i = 0; i < rr_len; i++) {
398 oop p = rr->obj_at(i);
399 if (java_lang_String::is_instance(p) &&
400 !ArchiveHeapWriter::is_string_too_large_to_archive(p)) {
401 HeapShared::add_to_dumped_interned_strings(p);
402 }
403 }
404 }
405 }
406 #endif
407
408 #if INCLUDE_CDS
409 // CDS support. Create a new resolved_references array.
410 void ConstantPool::restore_unshareable_info(TRAPS) {
411 if (!_pool_holder->is_linked() && !_pool_holder->is_rewritten()) {
412 return;
413 }
414 assert(is_constantPool(), "ensure C++ vtable is restored");
415 assert(on_stack(), "should always be set for shared constant pools");
416 assert(is_shared(), "should always be set for shared constant pools");
417 if (is_for_method_handle_intrinsic()) {
418 return;
419 }
420 assert(_cache != nullptr, "constant pool _cache should not be null");
421
422 // Only create the new resolved references array if it hasn't been attempted before
423 if (resolved_references() != nullptr) return;
424
425 if (vmClasses::Object_klass_loaded()) {
426 ClassLoaderData* loader_data = pool_holder()->class_loader_data();
427 #if INCLUDE_CDS_JAVA_HEAP
428 if (ArchiveHeapLoader::is_in_use() &&
429 _cache->archived_references() != nullptr) {
430 oop archived = _cache->archived_references();
431 // Create handle for the archived resolved reference array object
432 HandleMark hm(THREAD);
433 Handle refs_handle(THREAD, archived);
434 set_resolved_references(loader_data->add_handle(refs_handle));
435 _cache->clear_archived_references();
436 } else
437 #endif
438 {
439 // No mapped archived resolved reference array
440 // Recreate the object array and add to ClassLoaderData.
441 int map_length = resolved_reference_length();
442 if (map_length > 0) {
443 objArrayOop stom = oopFactory::new_objArray(vmClasses::Object_klass(), map_length, CHECK);
444 HandleMark hm(THREAD);
445 Handle refs_handle(THREAD, stom); // must handleize.
446 set_resolved_references(loader_data->add_handle(refs_handle));
447 }
448 }
449 }
450
451 if (CDSConfig::is_dumping_final_static_archive() && resolved_references() != nullptr) {
452 objArrayOop scratch_references = oopFactory::new_objArray(vmClasses::Object_klass(), resolved_references()->length(), CHECK);
453 HeapShared::add_scratch_resolved_references(this, scratch_references);
454 }
455 }
456
457 void ConstantPool::remove_unshareable_info() {
458 // Shared ConstantPools are in the RO region, so the _flags cannot be modified.
459 // The _on_stack flag is used to prevent ConstantPools from deallocation during
460 // class redefinition. Since shared ConstantPools cannot be deallocated anyway,
461 // we always set _on_stack to true to avoid having to change _flags during runtime.
462 _flags |= (_on_stack | _is_shared);
463
464 if (!ArchiveBuilder::current()->get_source_addr(_pool_holder)->is_linked()) {
465 return;
466 }
467
468 if (is_for_method_handle_intrinsic()) {
469 // This CP was created by Method::make_method_handle_intrinsic() and has nothing
470 // that need to be removed/restored. It has no cpCache since the intrinsic methods
471 // don't have any bytecodes.
472 assert(cache() == NULL, "must not have cpCache");
473 return;
474 }
475
476 // resolved_references(): remember its length. If it cannot be restored
477 // from the archived heap objects at run time, we need to dynamically allocate it.
478 if (cache() != nullptr) {
479 set_resolved_reference_length(
480 resolved_references() != nullptr ? resolved_references()->length() : 0);
481 set_resolved_references(OopHandle());
482 }
483 remove_unshareable_entries();
484 }
485
486 static const char* get_type(Klass* k) {
487 const char* type;
488 Klass* src_k;
489 if (ArchiveBuilder::is_active() && ArchiveBuilder::current()->is_in_buffer_space(k)) {
490 src_k = ArchiveBuilder::current()->get_source_addr(k);
491 } else {
492 src_k = k;
493 }
494
495 if (src_k->is_objArray_klass()) {
496 src_k = ObjArrayKlass::cast(src_k)->bottom_klass();
497 assert(!src_k->is_objArray_klass(), "sanity");
498 }
499
500 if (src_k->is_typeArray_klass()) {
501 type = "prim";
502 } else {
503 InstanceKlass* src_ik = InstanceKlass::cast(src_k);
504 oop loader = src_ik->class_loader();
505 if (loader == nullptr) {
506 type = "boot";
507 } else if (loader == SystemDictionary::java_platform_loader()) {
508 type = "plat";
509 } else if (loader == SystemDictionary::java_system_loader()) {
510 type = "app";
511 } else {
512 type = "unreg";
513 }
514 }
515
516 return type;
517 }
518
519 void ConstantPool::remove_unshareable_entries() {
520 ResourceMark rm;
521 log_info(cds, resolve)("Archiving CP entries for %s", pool_holder()->name()->as_C_string());
522 for (int cp_index = 1; cp_index < length(); cp_index++) { // cp_index 0 is unused
523 int cp_tag = tag_at(cp_index).value();
524 switch (cp_tag) {
525 case JVM_CONSTANT_UnresolvedClass:
526 ArchiveBuilder::alloc_stats()->record_klass_cp_entry(false, false);
527 break;
528 case JVM_CONSTANT_UnresolvedClassInError:
529 tag_at_put(cp_index, JVM_CONSTANT_UnresolvedClass);
530 ArchiveBuilder::alloc_stats()->record_klass_cp_entry(false, true);
531 break;
532 case JVM_CONSTANT_MethodHandleInError:
533 tag_at_put(cp_index, JVM_CONSTANT_MethodHandle);
534 break;
535 case JVM_CONSTANT_MethodTypeInError:
536 tag_at_put(cp_index, JVM_CONSTANT_MethodType);
537 break;
538 case JVM_CONSTANT_DynamicInError:
539 tag_at_put(cp_index, JVM_CONSTANT_Dynamic);
540 break;
541 case JVM_CONSTANT_Class:
542 remove_resolved_klass_if_non_deterministic(cp_index);
543 break;
544 default:
545 break;
546 }
547 }
548
549 if (cache() != nullptr) {
550 // cache() is null if this class is not yet linked.
551 cache()->remove_unshareable_info();
552 }
553 }
554
555 void ConstantPool::remove_resolved_klass_if_non_deterministic(int cp_index) {
556 assert(ArchiveBuilder::current()->is_in_buffer_space(this), "must be");
557 assert(tag_at(cp_index).is_klass(), "must be resolved");
558
559 Klass* k = resolved_klass_at(cp_index);
560 bool can_archive;
561
562 if (k == nullptr) {
563 // We'd come here if the referenced class has been excluded via
564 // SystemDictionaryShared::is_excluded_class(). As a result, ArchiveBuilder
565 // has cleared the resolved_klasses()->at(...) pointer to NULL. Thus, we
566 // need to revert the tag to JVM_CONSTANT_UnresolvedClass.
567 can_archive = false;
568 } else {
569 ConstantPool* src_cp = ArchiveBuilder::current()->get_source_addr(this);
570 can_archive = AOTConstantPoolResolver::is_resolution_deterministic(src_cp, cp_index);
571 }
572
573 if (!can_archive) {
574 int resolved_klass_index = klass_slot_at(cp_index).resolved_klass_index();
575 resolved_klasses()->at_put(resolved_klass_index, nullptr);
576 tag_at_put(cp_index, JVM_CONSTANT_UnresolvedClass);
577 }
578
579 LogStreamHandle(Trace, cds, resolve) log;
580 if (log.is_enabled()) {
581 ResourceMark rm;
582 log.print("%s klass CP entry [%3d]: %s %s",
583 (can_archive ? "archived" : "reverted"),
584 cp_index, pool_holder()->name()->as_C_string(), get_type(pool_holder()));
585 if (can_archive) {
586 log.print(" => %s %s%s", k->name()->as_C_string(), get_type(k),
587 (!k->is_instance_klass() || pool_holder()->is_subtype_of(k)) ? "" : " (not supertype)");
588 } else {
589 Symbol* name = klass_name_at(cp_index);
590 log.print(" => %s", name->as_C_string());
591 }
592 }
593
594 ArchiveBuilder::alloc_stats()->record_klass_cp_entry(can_archive, /*reverted=*/!can_archive);
595 }
596 #endif // INCLUDE_CDS
597
598 int ConstantPool::cp_to_object_index(int cp_index) {
599 // this is harder don't do this so much.
600 int i = reference_map()->find(checked_cast<u2>(cp_index));
601 // We might not find the index for jsr292 call.
602 return (i < 0) ? _no_index_sentinel : i;
603 }
604
605 void ConstantPool::string_at_put(int obj_index, oop str) {
606 oop result = set_resolved_reference_at(obj_index, str);
607 assert(result == nullptr || result == str, "Only set once or to the same string.");
608 }
609
610 void ConstantPool::trace_class_resolution(const constantPoolHandle& this_cp, Klass* k) {
611 ResourceMark rm;
612 int line_number = -1;
613 const char * source_file = nullptr;
614 if (JavaThread::current()->has_last_Java_frame()) {
615 // try to identify the method which called this function.
616 vframeStream vfst(JavaThread::current());
617 if (!vfst.at_end()) {
618 line_number = vfst.method()->line_number_from_bci(vfst.bci());
619 Symbol* s = vfst.method()->method_holder()->source_file_name();
620 if (s != nullptr) {
621 source_file = s->as_C_string();
622 }
623 }
624 }
625 if (k != this_cp->pool_holder()) {
626 // only print something if the classes are different
627 if (source_file != nullptr) {
628 log_debug(class, resolve)("%s %s %s:%d",
629 this_cp->pool_holder()->external_name(),
630 k->external_name(), source_file, line_number);
631 } else {
632 log_debug(class, resolve)("%s %s",
633 this_cp->pool_holder()->external_name(),
634 k->external_name());
635 }
636 }
637 }
638
639 Klass* ConstantPool::klass_at_impl(const constantPoolHandle& this_cp, int cp_index,
640 TRAPS) {
641 JavaThread* javaThread = THREAD;
642
643 // A resolved constantPool entry will contain a Klass*, otherwise a Symbol*.
644 // It is not safe to rely on the tag bit's here, since we don't have a lock, and
645 // the entry and tag is not updated atomically.
646 CPKlassSlot kslot = this_cp->klass_slot_at(cp_index);
647 int resolved_klass_index = kslot.resolved_klass_index();
648 int name_index = kslot.name_index();
649 assert(this_cp->tag_at(name_index).is_symbol(), "sanity");
650
651 // The tag must be JVM_CONSTANT_Class in order to read the correct value from
652 // the unresolved_klasses() array.
653 if (this_cp->tag_at(cp_index).is_klass()) {
654 Klass* klass = this_cp->resolved_klasses()->at(resolved_klass_index);
655 if (klass != nullptr) {
656 return klass;
657 }
658 }
659
660 // This tag doesn't change back to unresolved class unless at a safepoint.
661 if (this_cp->tag_at(cp_index).is_unresolved_klass_in_error()) {
662 // The original attempt to resolve this constant pool entry failed so find the
663 // class of the original error and throw another error of the same class
664 // (JVMS 5.4.3).
665 // If there is a detail message, pass that detail message to the error.
666 // The JVMS does not strictly require us to duplicate the same detail message,
667 // or any internal exception fields such as cause or stacktrace. But since the
668 // detail message is often a class name or other literal string, we will repeat it
669 // if we can find it in the symbol table.
670 throw_resolution_error(this_cp, cp_index, CHECK_NULL);
671 ShouldNotReachHere();
672 }
673
674 HandleMark hm(THREAD);
675 Handle mirror_handle;
676 Symbol* name = this_cp->symbol_at(name_index);
677 Handle loader (THREAD, this_cp->pool_holder()->class_loader());
678 Handle protection_domain (THREAD, this_cp->pool_holder()->protection_domain());
679
680 Klass* k;
681 {
682 // Turn off the single stepping while doing class resolution
683 JvmtiHideSingleStepping jhss(javaThread);
684 k = SystemDictionary::resolve_or_fail(name, loader, protection_domain, true, THREAD);
685 } // JvmtiHideSingleStepping jhss(javaThread);
686
687 if (!HAS_PENDING_EXCEPTION) {
688 // preserve the resolved klass from unloading
689 mirror_handle = Handle(THREAD, k->java_mirror());
690 // Do access check for klasses
691 verify_constant_pool_resolve(this_cp, k, THREAD);
692 }
693
694 // Failed to resolve class. We must record the errors so that subsequent attempts
695 // to resolve this constant pool entry fail with the same error (JVMS 5.4.3).
696 if (HAS_PENDING_EXCEPTION) {
697 save_and_throw_exception(this_cp, cp_index, constantTag(JVM_CONSTANT_UnresolvedClass), CHECK_NULL);
698 // If CHECK_NULL above doesn't return the exception, that means that
699 // some other thread has beaten us and has resolved the class.
700 // To preserve old behavior, we return the resolved class.
701 Klass* klass = this_cp->resolved_klasses()->at(resolved_klass_index);
702 assert(klass != nullptr, "must be resolved if exception was cleared");
703 return klass;
704 }
705
706 // logging for class+resolve.
707 if (log_is_enabled(Debug, class, resolve)){
708 trace_class_resolution(this_cp, k);
709 }
710
711 Klass** adr = this_cp->resolved_klasses()->adr_at(resolved_klass_index);
712 Atomic::release_store(adr, k);
713 // The interpreter assumes when the tag is stored, the klass is resolved
714 // and the Klass* stored in _resolved_klasses is non-null, so we need
715 // hardware store ordering here.
716 // We also need to CAS to not overwrite an error from a racing thread.
717
718 jbyte old_tag = Atomic::cmpxchg((jbyte*)this_cp->tag_addr_at(cp_index),
719 (jbyte)JVM_CONSTANT_UnresolvedClass,
720 (jbyte)JVM_CONSTANT_Class);
721
722 // We need to recheck exceptions from racing thread and return the same.
723 if (old_tag == JVM_CONSTANT_UnresolvedClassInError) {
724 // Remove klass.
725 this_cp->resolved_klasses()->at_put(resolved_klass_index, nullptr);
726 throw_resolution_error(this_cp, cp_index, CHECK_NULL);
727 }
728
729 return k;
730 }
731
732
733 // Does not update ConstantPool* - to avoid any exception throwing. Used
734 // by compiler and exception handling. Also used to avoid classloads for
735 // instanceof operations. Returns null if the class has not been loaded or
736 // if the verification of constant pool failed
737 Klass* ConstantPool::klass_at_if_loaded(const constantPoolHandle& this_cp, int which) {
738 CPKlassSlot kslot = this_cp->klass_slot_at(which);
739 int resolved_klass_index = kslot.resolved_klass_index();
740 int name_index = kslot.name_index();
741 assert(this_cp->tag_at(name_index).is_symbol(), "sanity");
742
743 if (this_cp->tag_at(which).is_klass()) {
744 Klass* k = this_cp->resolved_klasses()->at(resolved_klass_index);
745 assert(k != nullptr, "should be resolved");
746 return k;
747 } else if (this_cp->tag_at(which).is_unresolved_klass_in_error()) {
748 return nullptr;
749 } else {
750 Thread* current = Thread::current();
751 HandleMark hm(current);
752 Symbol* name = this_cp->symbol_at(name_index);
753 oop loader = this_cp->pool_holder()->class_loader();
754 oop protection_domain = this_cp->pool_holder()->protection_domain();
755 Handle h_prot (current, protection_domain);
756 Handle h_loader (current, loader);
757 Klass* k = SystemDictionary::find_instance_klass(current, name, h_loader, h_prot);
758
759 // Avoid constant pool verification at a safepoint, as it takes the Module_lock.
760 if (k != nullptr && current->is_Java_thread()) {
761 // Make sure that resolving is legal
762 JavaThread* THREAD = JavaThread::cast(current); // For exception macros.
763 ExceptionMark em(THREAD);
764 // return null if verification fails
765 verify_constant_pool_resolve(this_cp, k, THREAD);
766 if (HAS_PENDING_EXCEPTION) {
767 CLEAR_PENDING_EXCEPTION;
768 return nullptr;
769 }
770 return k;
771 } else {
772 return k;
773 }
774 }
775 }
776
777 Method* ConstantPool::method_at_if_loaded(const constantPoolHandle& cpool,
778 int which) {
779 if (cpool->cache() == nullptr) return nullptr; // nothing to load yet
780 if (!(which >= 0 && which < cpool->resolved_method_entries_length())) {
781 // FIXME: should be an assert
782 log_debug(class, resolve)("bad operand %d in:", which); cpool->print();
783 return nullptr;
784 }
785 return cpool->cache()->method_if_resolved(which);
786 }
787
788
789 bool ConstantPool::has_appendix_at_if_loaded(const constantPoolHandle& cpool, int which, Bytecodes::Code code) {
790 if (cpool->cache() == nullptr) return false; // nothing to load yet
791 if (code == Bytecodes::_invokedynamic) {
792 return cpool->resolved_indy_entry_at(which)->has_appendix();
793 } else {
794 return cpool->resolved_method_entry_at(which)->has_appendix();
795 }
796 }
797
798 oop ConstantPool::appendix_at_if_loaded(const constantPoolHandle& cpool, int which, Bytecodes::Code code) {
799 if (cpool->cache() == nullptr) return nullptr; // nothing to load yet
800 if (code == Bytecodes::_invokedynamic) {
801 return cpool->resolved_reference_from_indy(which);
802 } else {
803 return cpool->cache()->appendix_if_resolved(which);
804 }
805 }
806
807
808 bool ConstantPool::has_local_signature_at_if_loaded(const constantPoolHandle& cpool, int which, Bytecodes::Code code) {
809 if (cpool->cache() == nullptr) return false; // nothing to load yet
810 if (code == Bytecodes::_invokedynamic) {
811 return cpool->resolved_indy_entry_at(which)->has_local_signature();
812 } else {
813 return cpool->resolved_method_entry_at(which)->has_local_signature();
814 }
815 }
816
817 // Translate index, which could be CPCache index or Indy index, to a constant pool index
818 int ConstantPool::to_cp_index(int index, Bytecodes::Code code) {
819 assert(cache() != nullptr, "'index' is a rewritten index so this class must have been rewritten");
820 switch(code) {
821 case Bytecodes::_invokedynamic:
822 return invokedynamic_bootstrap_ref_index_at(index);
823 case Bytecodes::_getfield:
824 case Bytecodes::_getstatic:
825 case Bytecodes::_putfield:
826 case Bytecodes::_putstatic:
827 return resolved_field_entry_at(index)->constant_pool_index();
828 case Bytecodes::_invokeinterface:
829 case Bytecodes::_invokehandle:
830 case Bytecodes::_invokespecial:
831 case Bytecodes::_invokestatic:
832 case Bytecodes::_invokevirtual:
833 case Bytecodes::_fast_invokevfinal: // Bytecode interpreter uses this
834 return resolved_method_entry_at(index)->constant_pool_index();
835 default:
836 fatal("Unexpected bytecode: %s", Bytecodes::name(code));
837 }
838 }
839
840 bool ConstantPool::is_resolved(int index, Bytecodes::Code code) {
841 assert(cache() != nullptr, "'index' is a rewritten index so this class must have been rewritten");
842 switch(code) {
843 case Bytecodes::_invokedynamic:
844 return resolved_indy_entry_at(index)->is_resolved();
845
846 case Bytecodes::_getfield:
847 case Bytecodes::_getstatic:
848 case Bytecodes::_putfield:
849 case Bytecodes::_putstatic:
850 return resolved_field_entry_at(index)->is_resolved(code);
851
852 case Bytecodes::_invokeinterface:
853 case Bytecodes::_invokehandle:
854 case Bytecodes::_invokespecial:
855 case Bytecodes::_invokestatic:
856 case Bytecodes::_invokevirtual:
857 case Bytecodes::_fast_invokevfinal: // Bytecode interpreter uses this
858 return resolved_method_entry_at(index)->is_resolved(code);
859
860 default:
861 fatal("Unexpected bytecode: %s", Bytecodes::name(code));
862 }
863 }
864
865 u2 ConstantPool::uncached_name_and_type_ref_index_at(int cp_index) {
866 if (tag_at(cp_index).has_bootstrap()) {
867 u2 pool_index = bootstrap_name_and_type_ref_index_at(cp_index);
868 assert(tag_at(pool_index).is_name_and_type(), "");
869 return pool_index;
870 }
871 assert(tag_at(cp_index).is_field_or_method(), "Corrupted constant pool");
872 assert(!tag_at(cp_index).has_bootstrap(), "Must be handled above");
873 jint ref_index = *int_at_addr(cp_index);
874 return extract_high_short_from_int(ref_index);
875 }
876
877 u2 ConstantPool::name_and_type_ref_index_at(int index, Bytecodes::Code code) {
878 return uncached_name_and_type_ref_index_at(to_cp_index(index, code));
879 }
880
881 constantTag ConstantPool::tag_ref_at(int which, Bytecodes::Code code) {
882 // which may be either a Constant Pool index or a rewritten index
883 int pool_index = which;
884 assert(cache() != nullptr, "'index' is a rewritten index so this class must have been rewritten");
885 pool_index = to_cp_index(which, code);
886 return tag_at(pool_index);
887 }
888
889 u2 ConstantPool::uncached_klass_ref_index_at(int cp_index) {
890 assert(tag_at(cp_index).is_field_or_method(), "Corrupted constant pool");
891 jint ref_index = *int_at_addr(cp_index);
892 return extract_low_short_from_int(ref_index);
893 }
894
895 u2 ConstantPool::klass_ref_index_at(int index, Bytecodes::Code code) {
896 assert(code != Bytecodes::_invokedynamic,
897 "an invokedynamic instruction does not have a klass");
898 return uncached_klass_ref_index_at(to_cp_index(index, code));
899 }
900
901 void ConstantPool::verify_constant_pool_resolve(const constantPoolHandle& this_cp, Klass* k, TRAPS) {
902 if (!(k->is_instance_klass() || k->is_objArray_klass())) {
903 return; // short cut, typeArray klass is always accessible
904 }
905 Klass* holder = this_cp->pool_holder();
906 LinkResolver::check_klass_accessibility(holder, k, CHECK);
907 }
908
909
910 u2 ConstantPool::name_ref_index_at(int cp_index) {
911 jint ref_index = name_and_type_at(cp_index);
912 return extract_low_short_from_int(ref_index);
913 }
914
915
916 u2 ConstantPool::signature_ref_index_at(int cp_index) {
917 jint ref_index = name_and_type_at(cp_index);
918 return extract_high_short_from_int(ref_index);
919 }
920
921
922 Klass* ConstantPool::klass_ref_at(int which, Bytecodes::Code code, TRAPS) {
923 return klass_at(klass_ref_index_at(which, code), THREAD);
924 }
925
926 Symbol* ConstantPool::klass_name_at(int cp_index) const {
927 return symbol_at(klass_slot_at(cp_index).name_index());
928 }
929
930 Symbol* ConstantPool::klass_ref_at_noresolve(int which, Bytecodes::Code code) {
931 jint ref_index = klass_ref_index_at(which, code);
932 return klass_at_noresolve(ref_index);
933 }
934
935 Symbol* ConstantPool::uncached_klass_ref_at_noresolve(int cp_index) {
936 jint ref_index = uncached_klass_ref_index_at(cp_index);
937 return klass_at_noresolve(ref_index);
938 }
939
940 char* ConstantPool::string_at_noresolve(int cp_index) {
941 return unresolved_string_at(cp_index)->as_C_string();
942 }
943
944 BasicType ConstantPool::basic_type_for_signature_at(int cp_index) const {
945 return Signature::basic_type(symbol_at(cp_index));
946 }
947
948
949 void ConstantPool::resolve_string_constants_impl(const constantPoolHandle& this_cp, TRAPS) {
950 for (int index = 1; index < this_cp->length(); index++) { // Index 0 is unused
951 if (this_cp->tag_at(index).is_string()) {
952 this_cp->string_at(index, CHECK);
953 }
954 }
955 }
956
957 static const char* exception_message(const constantPoolHandle& this_cp, int which, constantTag tag, oop pending_exception) {
958 // Note: caller needs ResourceMark
959
960 // Dig out the detailed message to reuse if possible
961 const char* msg = java_lang_Throwable::message_as_utf8(pending_exception);
962 if (msg != nullptr) {
963 return msg;
964 }
965
966 Symbol* message = nullptr;
967 // Return specific message for the tag
968 switch (tag.value()) {
969 case JVM_CONSTANT_UnresolvedClass:
970 // return the class name in the error message
971 message = this_cp->klass_name_at(which);
972 break;
973 case JVM_CONSTANT_MethodHandle:
974 // return the method handle name in the error message
975 message = this_cp->method_handle_name_ref_at(which);
976 break;
977 case JVM_CONSTANT_MethodType:
978 // return the method type signature in the error message
979 message = this_cp->method_type_signature_at(which);
980 break;
981 case JVM_CONSTANT_Dynamic:
982 // return the name of the condy in the error message
983 message = this_cp->uncached_name_ref_at(which);
984 break;
985 default:
986 ShouldNotReachHere();
987 }
988
989 return message != nullptr ? message->as_C_string() : nullptr;
990 }
991
992 static void add_resolution_error(JavaThread* current, const constantPoolHandle& this_cp, int which,
993 constantTag tag, oop pending_exception) {
994
995 ResourceMark rm(current);
996 Symbol* error = pending_exception->klass()->name();
997 oop cause = java_lang_Throwable::cause(pending_exception);
998
999 // Also dig out the exception cause, if present.
1000 Symbol* cause_sym = nullptr;
1001 const char* cause_msg = nullptr;
1002 if (cause != nullptr && cause != pending_exception) {
1003 cause_sym = cause->klass()->name();
1004 cause_msg = java_lang_Throwable::message_as_utf8(cause);
1005 }
1006
1007 const char* message = exception_message(this_cp, which, tag, pending_exception);
1008 SystemDictionary::add_resolution_error(this_cp, which, error, message, cause_sym, cause_msg);
1009 }
1010
1011
1012 void ConstantPool::throw_resolution_error(const constantPoolHandle& this_cp, int which, TRAPS) {
1013 ResourceMark rm(THREAD);
1014 const char* message = nullptr;
1015 Symbol* cause = nullptr;
1016 const char* cause_msg = nullptr;
1017 Symbol* error = SystemDictionary::find_resolution_error(this_cp, which, &message, &cause, &cause_msg);
1018 assert(error != nullptr, "checking");
1019
1020 CLEAR_PENDING_EXCEPTION;
1021 if (message != nullptr) {
1022 if (cause != nullptr) {
1023 Handle h_cause = Exceptions::new_exception(THREAD, cause, cause_msg);
1024 THROW_MSG_CAUSE(error, message, h_cause);
1025 } else {
1026 THROW_MSG(error, message);
1027 }
1028 } else {
1029 if (cause != nullptr) {
1030 Handle h_cause = Exceptions::new_exception(THREAD, cause, cause_msg);
1031 THROW_CAUSE(error, h_cause);
1032 } else {
1033 THROW(error);
1034 }
1035 }
1036 }
1037
1038 // If resolution for Class, Dynamic constant, MethodHandle or MethodType fails, save the
1039 // exception in the resolution error table, so that the same exception is thrown again.
1040 void ConstantPool::save_and_throw_exception(const constantPoolHandle& this_cp, int cp_index,
1041 constantTag tag, TRAPS) {
1042
1043 int error_tag = tag.error_value();
1044
1045 if (!PENDING_EXCEPTION->
1046 is_a(vmClasses::LinkageError_klass())) {
1047 // Just throw the exception and don't prevent these classes from
1048 // being loaded due to virtual machine errors like StackOverflow
1049 // and OutOfMemoryError, etc, or if the thread was hit by stop()
1050 // Needs clarification to section 5.4.3 of the VM spec (see 6308271)
1051 } else if (this_cp->tag_at(cp_index).value() != error_tag) {
1052 add_resolution_error(THREAD, this_cp, cp_index, tag, PENDING_EXCEPTION);
1053 // CAS in the tag. If a thread beat us to registering this error that's fine.
1054 // If another thread resolved the reference, this is a race condition. This
1055 // thread may have had a security manager or something temporary.
1056 // This doesn't deterministically get an error. So why do we save this?
1057 // We save this because jvmti can add classes to the bootclass path after
1058 // this error, so it needs to get the same error if the error is first.
1059 jbyte old_tag = Atomic::cmpxchg((jbyte*)this_cp->tag_addr_at(cp_index),
1060 (jbyte)tag.value(),
1061 (jbyte)error_tag);
1062 if (old_tag != error_tag && old_tag != tag.value()) {
1063 // MethodHandles and MethodType doesn't change to resolved version.
1064 assert(this_cp->tag_at(cp_index).is_klass(), "Wrong tag value");
1065 // Forget the exception and use the resolved class.
1066 CLEAR_PENDING_EXCEPTION;
1067 }
1068 } else {
1069 // some other thread put this in error state
1070 throw_resolution_error(this_cp, cp_index, CHECK);
1071 }
1072 }
1073
1074 constantTag ConstantPool::constant_tag_at(int cp_index) {
1075 constantTag tag = tag_at(cp_index);
1076 if (tag.is_dynamic_constant()) {
1077 BasicType bt = basic_type_for_constant_at(cp_index);
1078 return constantTag(constantTag::type2tag(bt));
1079 }
1080 return tag;
1081 }
1082
1083 BasicType ConstantPool::basic_type_for_constant_at(int cp_index) {
1084 constantTag tag = tag_at(cp_index);
1085 if (tag.is_dynamic_constant() ||
1086 tag.is_dynamic_constant_in_error()) {
1087 // have to look at the signature for this one
1088 Symbol* constant_type = uncached_signature_ref_at(cp_index);
1089 return Signature::basic_type(constant_type);
1090 }
1091 return tag.basic_type();
1092 }
1093
1094 // Called to resolve constants in the constant pool and return an oop.
1095 // Some constant pool entries cache their resolved oop. This is also
1096 // called to create oops from constants to use in arguments for invokedynamic
1097 oop ConstantPool::resolve_constant_at_impl(const constantPoolHandle& this_cp,
1098 int cp_index, int cache_index,
1099 bool* status_return, TRAPS) {
1100 oop result_oop = nullptr;
1101
1102 if (cache_index == _possible_index_sentinel) {
1103 // It is possible that this constant is one which is cached in the objects.
1104 // We'll do a linear search. This should be OK because this usage is rare.
1105 // FIXME: If bootstrap specifiers stress this code, consider putting in
1106 // a reverse index. Binary search over a short array should do it.
1107 assert(cp_index > 0, "valid constant pool index");
1108 cache_index = this_cp->cp_to_object_index(cp_index);
1109 }
1110 assert(cache_index == _no_index_sentinel || cache_index >= 0, "");
1111 assert(cp_index == _no_index_sentinel || cp_index >= 0, "");
1112
1113 if (cache_index >= 0) {
1114 result_oop = this_cp->resolved_reference_at(cache_index);
1115 if (result_oop != nullptr) {
1116 if (result_oop == Universe::the_null_sentinel()) {
1117 DEBUG_ONLY(int temp_index = (cp_index >= 0 ? cp_index : this_cp->object_to_cp_index(cache_index)));
1118 assert(this_cp->tag_at(temp_index).is_dynamic_constant(), "only condy uses the null sentinel");
1119 result_oop = nullptr;
1120 }
1121 if (status_return != nullptr) (*status_return) = true;
1122 return result_oop;
1123 // That was easy...
1124 }
1125 cp_index = this_cp->object_to_cp_index(cache_index);
1126 }
1127
1128 jvalue prim_value; // temp used only in a few cases below
1129
1130 constantTag tag = this_cp->tag_at(cp_index);
1131
1132 if (status_return != nullptr) {
1133 // don't trigger resolution if the constant might need it
1134 switch (tag.value()) {
1135 case JVM_CONSTANT_Class:
1136 {
1137 CPKlassSlot kslot = this_cp->klass_slot_at(cp_index);
1138 int resolved_klass_index = kslot.resolved_klass_index();
1139 if (this_cp->resolved_klasses()->at(resolved_klass_index) == nullptr) {
1140 (*status_return) = false;
1141 return nullptr;
1142 }
1143 // the klass is waiting in the CP; go get it
1144 break;
1145 }
1146 case JVM_CONSTANT_String:
1147 case JVM_CONSTANT_Integer:
1148 case JVM_CONSTANT_Float:
1149 case JVM_CONSTANT_Long:
1150 case JVM_CONSTANT_Double:
1151 // these guys trigger OOM at worst
1152 break;
1153 default:
1154 (*status_return) = false;
1155 return nullptr;
1156 }
1157 // from now on there is either success or an OOME
1158 (*status_return) = true;
1159 }
1160
1161 switch (tag.value()) {
1162
1163 case JVM_CONSTANT_UnresolvedClass:
1164 case JVM_CONSTANT_Class:
1165 {
1166 assert(cache_index == _no_index_sentinel, "should not have been set");
1167 Klass* resolved = klass_at_impl(this_cp, cp_index, CHECK_NULL);
1168 // ldc wants the java mirror.
1169 result_oop = resolved->java_mirror();
1170 break;
1171 }
1172
1173 case JVM_CONSTANT_Dynamic:
1174 { PerfTraceTimedEvent timer(ClassLoader::perf_resolve_invokedynamic_time(),
1175 ClassLoader::perf_resolve_invokedynamic_count());
1176
1177 // Resolve the Dynamically-Computed constant to invoke the BSM in order to obtain the resulting oop.
1178 BootstrapInfo bootstrap_specifier(this_cp, cp_index);
1179
1180 // The initial step in resolving an unresolved symbolic reference to a
1181 // dynamically-computed constant is to resolve the symbolic reference to a
1182 // method handle which will be the bootstrap method for the dynamically-computed
1183 // constant. If resolution of the java.lang.invoke.MethodHandle for the bootstrap
1184 // method fails, then a MethodHandleInError is stored at the corresponding
1185 // bootstrap method's CP index for the CONSTANT_MethodHandle_info. No need to
1186 // set a DynamicConstantInError here since any subsequent use of this
1187 // bootstrap method will encounter the resolution of MethodHandleInError.
1188 // Both the first, (resolution of the BSM and its static arguments), and the second tasks,
1189 // (invocation of the BSM), of JVMS Section 5.4.3.6 occur within invoke_bootstrap_method()
1190 // for the bootstrap_specifier created above.
1191 SystemDictionary::invoke_bootstrap_method(bootstrap_specifier, THREAD);
1192 Exceptions::wrap_dynamic_exception(/* is_indy */ false, THREAD);
1193 if (HAS_PENDING_EXCEPTION) {
1194 // Resolution failure of the dynamically-computed constant, save_and_throw_exception
1195 // will check for a LinkageError and store a DynamicConstantInError.
1196 save_and_throw_exception(this_cp, cp_index, tag, CHECK_NULL);
1197 }
1198 result_oop = bootstrap_specifier.resolved_value()();
1199 BasicType type = Signature::basic_type(bootstrap_specifier.signature());
1200 if (!is_reference_type(type)) {
1201 // Make sure the primitive value is properly boxed.
1202 // This is a JDK responsibility.
1203 const char* fail = nullptr;
1204 if (result_oop == nullptr) {
1205 fail = "null result instead of box";
1206 } else if (!is_java_primitive(type)) {
1207 // FIXME: support value types via unboxing
1208 fail = "can only handle references and primitives";
1209 } else if (!java_lang_boxing_object::is_instance(result_oop, type)) {
1210 fail = "primitive is not properly boxed";
1211 }
1212 if (fail != nullptr) {
1213 // Since this exception is not a LinkageError, throw exception
1214 // but do not save a DynamicInError resolution result.
1215 // See section 5.4.3 of the VM spec.
1216 THROW_MSG_NULL(vmSymbols::java_lang_InternalError(), fail);
1217 }
1218 }
1219
1220 LogTarget(Debug, methodhandles, condy) lt_condy;
1221 if (lt_condy.is_enabled()) {
1222 LogStream ls(lt_condy);
1223 bootstrap_specifier.print_msg_on(&ls, "resolve_constant_at_impl");
1224 }
1225 break;
1226 }
1227
1228 case JVM_CONSTANT_String:
1229 assert(cache_index != _no_index_sentinel, "should have been set");
1230 result_oop = string_at_impl(this_cp, cp_index, cache_index, CHECK_NULL);
1231 break;
1232
1233 case JVM_CONSTANT_MethodHandle:
1234 { PerfTraceTimedEvent timer(ClassLoader::perf_resolve_method_handle_time(),
1235 ClassLoader::perf_resolve_method_handle_count());
1236
1237 int ref_kind = this_cp->method_handle_ref_kind_at(cp_index);
1238 int callee_index = this_cp->method_handle_klass_index_at(cp_index);
1239 Symbol* name = this_cp->method_handle_name_ref_at(cp_index);
1240 Symbol* signature = this_cp->method_handle_signature_ref_at(cp_index);
1241 constantTag m_tag = this_cp->tag_at(this_cp->method_handle_index_at(cp_index));
1242 { ResourceMark rm(THREAD);
1243 log_debug(class, resolve)("resolve JVM_CONSTANT_MethodHandle:%d [%d/%d/%d] %s.%s",
1244 ref_kind, cp_index, this_cp->method_handle_index_at(cp_index),
1245 callee_index, name->as_C_string(), signature->as_C_string());
1246 }
1247
1248 Klass* callee = klass_at_impl(this_cp, callee_index, THREAD);
1249 if (HAS_PENDING_EXCEPTION) {
1250 save_and_throw_exception(this_cp, cp_index, tag, CHECK_NULL);
1251 }
1252
1253 // Check constant pool method consistency
1254 if ((callee->is_interface() && m_tag.is_method()) ||
1255 (!callee->is_interface() && m_tag.is_interface_method())) {
1256 ResourceMark rm(THREAD);
1257 stringStream ss;
1258 ss.print("Inconsistent constant pool data in classfile for class %s. "
1259 "Method '", callee->name()->as_C_string());
1260 signature->print_as_signature_external_return_type(&ss);
1261 ss.print(" %s(", name->as_C_string());
1262 signature->print_as_signature_external_parameters(&ss);
1263 ss.print(")' at index %d is %s and should be %s",
1264 cp_index,
1265 callee->is_interface() ? "CONSTANT_MethodRef" : "CONSTANT_InterfaceMethodRef",
1266 callee->is_interface() ? "CONSTANT_InterfaceMethodRef" : "CONSTANT_MethodRef");
1267 Exceptions::fthrow(THREAD_AND_LOCATION, vmSymbols::java_lang_IncompatibleClassChangeError(), "%s", ss.as_string());
1268 save_and_throw_exception(this_cp, cp_index, tag, CHECK_NULL);
1269 }
1270
1271 Klass* klass = this_cp->pool_holder();
1272 HandleMark hm(THREAD);
1273 Handle value = SystemDictionary::link_method_handle_constant(klass, ref_kind,
1274 callee, name, signature,
1275 THREAD);
1276 if (HAS_PENDING_EXCEPTION) {
1277 save_and_throw_exception(this_cp, cp_index, tag, CHECK_NULL);
1278 }
1279 result_oop = value();
1280 break;
1281 }
1282
1283 case JVM_CONSTANT_MethodType:
1284 { PerfTraceTimedEvent timer(ClassLoader::perf_resolve_method_type_time(),
1285 ClassLoader::perf_resolve_method_type_count());
1286
1287 Symbol* signature = this_cp->method_type_signature_at(cp_index);
1288 { ResourceMark rm(THREAD);
1289 log_debug(class, resolve)("resolve JVM_CONSTANT_MethodType [%d/%d] %s",
1290 cp_index, this_cp->method_type_index_at(cp_index),
1291 signature->as_C_string());
1292 }
1293 Klass* klass = this_cp->pool_holder();
1294 HandleMark hm(THREAD);
1295 Handle value = SystemDictionary::find_method_handle_type(signature, klass, THREAD);
1296 result_oop = value();
1297 if (HAS_PENDING_EXCEPTION) {
1298 save_and_throw_exception(this_cp, cp_index, tag, CHECK_NULL);
1299 }
1300 break;
1301 }
1302
1303 case JVM_CONSTANT_Integer:
1304 assert(cache_index == _no_index_sentinel, "should not have been set");
1305 prim_value.i = this_cp->int_at(cp_index);
1306 result_oop = java_lang_boxing_object::create(T_INT, &prim_value, CHECK_NULL);
1307 break;
1308
1309 case JVM_CONSTANT_Float:
1310 assert(cache_index == _no_index_sentinel, "should not have been set");
1311 prim_value.f = this_cp->float_at(cp_index);
1312 result_oop = java_lang_boxing_object::create(T_FLOAT, &prim_value, CHECK_NULL);
1313 break;
1314
1315 case JVM_CONSTANT_Long:
1316 assert(cache_index == _no_index_sentinel, "should not have been set");
1317 prim_value.j = this_cp->long_at(cp_index);
1318 result_oop = java_lang_boxing_object::create(T_LONG, &prim_value, CHECK_NULL);
1319 break;
1320
1321 case JVM_CONSTANT_Double:
1322 assert(cache_index == _no_index_sentinel, "should not have been set");
1323 prim_value.d = this_cp->double_at(cp_index);
1324 result_oop = java_lang_boxing_object::create(T_DOUBLE, &prim_value, CHECK_NULL);
1325 break;
1326
1327 case JVM_CONSTANT_UnresolvedClassInError:
1328 case JVM_CONSTANT_DynamicInError:
1329 case JVM_CONSTANT_MethodHandleInError:
1330 case JVM_CONSTANT_MethodTypeInError:
1331 throw_resolution_error(this_cp, cp_index, CHECK_NULL);
1332 break;
1333
1334 default:
1335 fatal("unexpected constant tag at CP %p[%d/%d] = %d", this_cp(), cp_index, cache_index, tag.value());
1336 break;
1337 }
1338
1339 if (cache_index >= 0) {
1340 // Benign race condition: resolved_references may already be filled in.
1341 // The important thing here is that all threads pick up the same result.
1342 // It doesn't matter which racing thread wins, as long as only one
1343 // result is used by all threads, and all future queries.
1344 oop new_result = (result_oop == nullptr ? Universe::the_null_sentinel() : result_oop);
1345 oop old_result = this_cp->set_resolved_reference_at(cache_index, new_result);
1346 if (old_result == nullptr) {
1347 return result_oop; // was installed
1348 } else {
1349 // Return the winning thread's result. This can be different than
1350 // the result here for MethodHandles.
1351 if (old_result == Universe::the_null_sentinel())
1352 old_result = nullptr;
1353 return old_result;
1354 }
1355 } else {
1356 assert(result_oop != Universe::the_null_sentinel(), "");
1357 return result_oop;
1358 }
1359 }
1360
1361 oop ConstantPool::uncached_string_at(int cp_index, TRAPS) {
1362 Symbol* sym = unresolved_string_at(cp_index);
1363 oop str = StringTable::intern(sym, CHECK_(nullptr));
1364 assert(java_lang_String::is_instance(str), "must be string");
1365 return str;
1366 }
1367
1368 void ConstantPool::copy_bootstrap_arguments_at_impl(const constantPoolHandle& this_cp, int cp_index,
1369 int start_arg, int end_arg,
1370 objArrayHandle info, int pos,
1371 bool must_resolve, Handle if_not_available,
1372 TRAPS) {
1373 int limit = pos + end_arg - start_arg;
1374 // checks: cp_index in range [0..this_cp->length),
1375 // tag at cp_index, start..end in range [0..this_cp->bootstrap_argument_count],
1376 // info array non-null, pos..limit in [0..info.length]
1377 if ((0 >= cp_index || cp_index >= this_cp->length()) ||
1378 !(this_cp->tag_at(cp_index).is_invoke_dynamic() ||
1379 this_cp->tag_at(cp_index).is_dynamic_constant()) ||
1380 (0 > start_arg || start_arg > end_arg) ||
1381 (end_arg > this_cp->bootstrap_argument_count_at(cp_index)) ||
1382 (0 > pos || pos > limit) ||
1383 (info.is_null() || limit > info->length())) {
1384 // An index or something else went wrong; throw an error.
1385 // Since this is an internal API, we don't expect this,
1386 // so we don't bother to craft a nice message.
1387 THROW_MSG(vmSymbols::java_lang_LinkageError(), "bad BSM argument access");
1388 }
1389 // now we can loop safely
1390 int info_i = pos;
1391 for (int i = start_arg; i < end_arg; i++) {
1392 int arg_index = this_cp->bootstrap_argument_index_at(cp_index, i);
1393 oop arg_oop;
1394 if (must_resolve) {
1395 arg_oop = this_cp->resolve_possibly_cached_constant_at(arg_index, CHECK);
1396 } else {
1397 bool found_it = false;
1398 arg_oop = this_cp->find_cached_constant_at(arg_index, found_it, CHECK);
1399 if (!found_it) arg_oop = if_not_available();
1400 }
1401 info->obj_at_put(info_i++, arg_oop);
1402 }
1403 }
1404
1405 oop ConstantPool::string_at_impl(const constantPoolHandle& this_cp, int cp_index, int obj_index, TRAPS) {
1406 // If the string has already been interned, this entry will be non-null
1407 oop str = this_cp->resolved_reference_at(obj_index);
1408 assert(str != Universe::the_null_sentinel(), "");
1409 if (str != nullptr) return str;
1410 Symbol* sym = this_cp->unresolved_string_at(cp_index);
1411 str = StringTable::intern(sym, CHECK_(nullptr));
1412 this_cp->string_at_put(obj_index, str);
1413 assert(java_lang_String::is_instance(str), "must be string");
1414 return str;
1415 }
1416
1417
1418 bool ConstantPool::klass_name_at_matches(const InstanceKlass* k, int cp_index) {
1419 // Names are interned, so we can compare Symbol*s directly
1420 Symbol* cp_name = klass_name_at(cp_index);
1421 return (cp_name == k->name());
1422 }
1423
1424
1425 // Iterate over symbols and decrement ones which are Symbol*s
1426 // This is done during GC.
1427 // Only decrement the UTF8 symbols. Strings point to
1428 // these symbols but didn't increment the reference count.
1429 void ConstantPool::unreference_symbols() {
1430 for (int index = 1; index < length(); index++) { // Index 0 is unused
1431 constantTag tag = tag_at(index);
1432 if (tag.is_symbol()) {
1433 symbol_at(index)->decrement_refcount();
1434 }
1435 }
1436 }
1437
1438
1439 // Compare this constant pool's entry at index1 to the constant pool
1440 // cp2's entry at index2.
1441 bool ConstantPool::compare_entry_to(int index1, const constantPoolHandle& cp2,
1442 int index2) {
1443
1444 // The error tags are equivalent to non-error tags when comparing
1445 jbyte t1 = tag_at(index1).non_error_value();
1446 jbyte t2 = cp2->tag_at(index2).non_error_value();
1447
1448 // Some classes are pre-resolved (like Throwable) which may lead to
1449 // consider it as a different entry. We then revert them back temporarily
1450 // to ensure proper comparison.
1451 if (t1 == JVM_CONSTANT_Class) {
1452 t1 = JVM_CONSTANT_UnresolvedClass;
1453 }
1454 if (t2 == JVM_CONSTANT_Class) {
1455 t2 = JVM_CONSTANT_UnresolvedClass;
1456 }
1457
1458 if (t1 != t2) {
1459 // Not the same entry type so there is nothing else to check. Note
1460 // that this style of checking will consider resolved/unresolved
1461 // class pairs as different.
1462 // From the ConstantPool* API point of view, this is correct
1463 // behavior. See VM_RedefineClasses::merge_constant_pools() to see how this
1464 // plays out in the context of ConstantPool* merging.
1465 return false;
1466 }
1467
1468 switch (t1) {
1469 case JVM_CONSTANT_ClassIndex:
1470 {
1471 int recur1 = klass_index_at(index1);
1472 int recur2 = cp2->klass_index_at(index2);
1473 if (compare_entry_to(recur1, cp2, recur2)) {
1474 return true;
1475 }
1476 } break;
1477
1478 case JVM_CONSTANT_Double:
1479 {
1480 jdouble d1 = double_at(index1);
1481 jdouble d2 = cp2->double_at(index2);
1482 if (d1 == d2) {
1483 return true;
1484 }
1485 } break;
1486
1487 case JVM_CONSTANT_Fieldref:
1488 case JVM_CONSTANT_InterfaceMethodref:
1489 case JVM_CONSTANT_Methodref:
1490 {
1491 int recur1 = uncached_klass_ref_index_at(index1);
1492 int recur2 = cp2->uncached_klass_ref_index_at(index2);
1493 bool match = compare_entry_to(recur1, cp2, recur2);
1494 if (match) {
1495 recur1 = uncached_name_and_type_ref_index_at(index1);
1496 recur2 = cp2->uncached_name_and_type_ref_index_at(index2);
1497 if (compare_entry_to(recur1, cp2, recur2)) {
1498 return true;
1499 }
1500 }
1501 } break;
1502
1503 case JVM_CONSTANT_Float:
1504 {
1505 jfloat f1 = float_at(index1);
1506 jfloat f2 = cp2->float_at(index2);
1507 if (f1 == f2) {
1508 return true;
1509 }
1510 } break;
1511
1512 case JVM_CONSTANT_Integer:
1513 {
1514 jint i1 = int_at(index1);
1515 jint i2 = cp2->int_at(index2);
1516 if (i1 == i2) {
1517 return true;
1518 }
1519 } break;
1520
1521 case JVM_CONSTANT_Long:
1522 {
1523 jlong l1 = long_at(index1);
1524 jlong l2 = cp2->long_at(index2);
1525 if (l1 == l2) {
1526 return true;
1527 }
1528 } break;
1529
1530 case JVM_CONSTANT_NameAndType:
1531 {
1532 int recur1 = name_ref_index_at(index1);
1533 int recur2 = cp2->name_ref_index_at(index2);
1534 if (compare_entry_to(recur1, cp2, recur2)) {
1535 recur1 = signature_ref_index_at(index1);
1536 recur2 = cp2->signature_ref_index_at(index2);
1537 if (compare_entry_to(recur1, cp2, recur2)) {
1538 return true;
1539 }
1540 }
1541 } break;
1542
1543 case JVM_CONSTANT_StringIndex:
1544 {
1545 int recur1 = string_index_at(index1);
1546 int recur2 = cp2->string_index_at(index2);
1547 if (compare_entry_to(recur1, cp2, recur2)) {
1548 return true;
1549 }
1550 } break;
1551
1552 case JVM_CONSTANT_UnresolvedClass:
1553 {
1554 Symbol* k1 = klass_name_at(index1);
1555 Symbol* k2 = cp2->klass_name_at(index2);
1556 if (k1 == k2) {
1557 return true;
1558 }
1559 } break;
1560
1561 case JVM_CONSTANT_MethodType:
1562 {
1563 int k1 = method_type_index_at(index1);
1564 int k2 = cp2->method_type_index_at(index2);
1565 if (compare_entry_to(k1, cp2, k2)) {
1566 return true;
1567 }
1568 } break;
1569
1570 case JVM_CONSTANT_MethodHandle:
1571 {
1572 int k1 = method_handle_ref_kind_at(index1);
1573 int k2 = cp2->method_handle_ref_kind_at(index2);
1574 if (k1 == k2) {
1575 int i1 = method_handle_index_at(index1);
1576 int i2 = cp2->method_handle_index_at(index2);
1577 if (compare_entry_to(i1, cp2, i2)) {
1578 return true;
1579 }
1580 }
1581 } break;
1582
1583 case JVM_CONSTANT_Dynamic:
1584 {
1585 int k1 = bootstrap_name_and_type_ref_index_at(index1);
1586 int k2 = cp2->bootstrap_name_and_type_ref_index_at(index2);
1587 int i1 = bootstrap_methods_attribute_index(index1);
1588 int i2 = cp2->bootstrap_methods_attribute_index(index2);
1589 bool match_entry = compare_entry_to(k1, cp2, k2);
1590 bool match_operand = compare_operand_to(i1, cp2, i2);
1591 return (match_entry && match_operand);
1592 } break;
1593
1594 case JVM_CONSTANT_InvokeDynamic:
1595 {
1596 int k1 = bootstrap_name_and_type_ref_index_at(index1);
1597 int k2 = cp2->bootstrap_name_and_type_ref_index_at(index2);
1598 int i1 = bootstrap_methods_attribute_index(index1);
1599 int i2 = cp2->bootstrap_methods_attribute_index(index2);
1600 bool match_entry = compare_entry_to(k1, cp2, k2);
1601 bool match_operand = compare_operand_to(i1, cp2, i2);
1602 return (match_entry && match_operand);
1603 } break;
1604
1605 case JVM_CONSTANT_String:
1606 {
1607 Symbol* s1 = unresolved_string_at(index1);
1608 Symbol* s2 = cp2->unresolved_string_at(index2);
1609 if (s1 == s2) {
1610 return true;
1611 }
1612 } break;
1613
1614 case JVM_CONSTANT_Utf8:
1615 {
1616 Symbol* s1 = symbol_at(index1);
1617 Symbol* s2 = cp2->symbol_at(index2);
1618 if (s1 == s2) {
1619 return true;
1620 }
1621 } break;
1622
1623 // Invalid is used as the tag for the second constant pool entry
1624 // occupied by JVM_CONSTANT_Double or JVM_CONSTANT_Long. It should
1625 // not be seen by itself.
1626 case JVM_CONSTANT_Invalid: // fall through
1627
1628 default:
1629 ShouldNotReachHere();
1630 break;
1631 }
1632
1633 return false;
1634 } // end compare_entry_to()
1635
1636
1637 // Resize the operands array with delta_len and delta_size.
1638 // Used in RedefineClasses for CP merge.
1639 void ConstantPool::resize_operands(int delta_len, int delta_size, TRAPS) {
1640 int old_len = operand_array_length(operands());
1641 int new_len = old_len + delta_len;
1642 int min_len = (delta_len > 0) ? old_len : new_len;
1643
1644 int old_size = operands()->length();
1645 int new_size = old_size + delta_size;
1646 int min_size = (delta_size > 0) ? old_size : new_size;
1647
1648 ClassLoaderData* loader_data = pool_holder()->class_loader_data();
1649 Array<u2>* new_ops = MetadataFactory::new_array<u2>(loader_data, new_size, CHECK);
1650
1651 // Set index in the resized array for existing elements only
1652 for (int idx = 0; idx < min_len; idx++) {
1653 int offset = operand_offset_at(idx); // offset in original array
1654 operand_offset_at_put(new_ops, idx, offset + 2*delta_len); // offset in resized array
1655 }
1656 // Copy the bootstrap specifiers only
1657 Copy::conjoint_memory_atomic(operands()->adr_at(2*old_len),
1658 new_ops->adr_at(2*new_len),
1659 (min_size - 2*min_len) * sizeof(u2));
1660 // Explicitly deallocate old operands array.
1661 // Note, it is not needed for 7u backport.
1662 if ( operands() != nullptr) { // the safety check
1663 MetadataFactory::free_array<u2>(loader_data, operands());
1664 }
1665 set_operands(new_ops);
1666 } // end resize_operands()
1667
1668
1669 // Extend the operands array with the length and size of the ext_cp operands.
1670 // Used in RedefineClasses for CP merge.
1671 void ConstantPool::extend_operands(const constantPoolHandle& ext_cp, TRAPS) {
1672 int delta_len = operand_array_length(ext_cp->operands());
1673 if (delta_len == 0) {
1674 return; // nothing to do
1675 }
1676 int delta_size = ext_cp->operands()->length();
1677
1678 assert(delta_len > 0 && delta_size > 0, "extended operands array must be bigger");
1679
1680 if (operand_array_length(operands()) == 0) {
1681 ClassLoaderData* loader_data = pool_holder()->class_loader_data();
1682 Array<u2>* new_ops = MetadataFactory::new_array<u2>(loader_data, delta_size, CHECK);
1683 // The first element index defines the offset of second part
1684 operand_offset_at_put(new_ops, 0, 2*delta_len); // offset in new array
1685 set_operands(new_ops);
1686 } else {
1687 resize_operands(delta_len, delta_size, CHECK);
1688 }
1689
1690 } // end extend_operands()
1691
1692
1693 // Shrink the operands array to a smaller array with new_len length.
1694 // Used in RedefineClasses for CP merge.
1695 void ConstantPool::shrink_operands(int new_len, TRAPS) {
1696 int old_len = operand_array_length(operands());
1697 if (new_len == old_len) {
1698 return; // nothing to do
1699 }
1700 assert(new_len < old_len, "shrunken operands array must be smaller");
1701
1702 int free_base = operand_next_offset_at(new_len - 1);
1703 int delta_len = new_len - old_len;
1704 int delta_size = 2*delta_len + free_base - operands()->length();
1705
1706 resize_operands(delta_len, delta_size, CHECK);
1707
1708 } // end shrink_operands()
1709
1710
1711 void ConstantPool::copy_operands(const constantPoolHandle& from_cp,
1712 const constantPoolHandle& to_cp,
1713 TRAPS) {
1714
1715 int from_oplen = operand_array_length(from_cp->operands());
1716 int old_oplen = operand_array_length(to_cp->operands());
1717 if (from_oplen != 0) {
1718 ClassLoaderData* loader_data = to_cp->pool_holder()->class_loader_data();
1719 // append my operands to the target's operands array
1720 if (old_oplen == 0) {
1721 // Can't just reuse from_cp's operand list because of deallocation issues
1722 int len = from_cp->operands()->length();
1723 Array<u2>* new_ops = MetadataFactory::new_array<u2>(loader_data, len, CHECK);
1724 Copy::conjoint_memory_atomic(
1725 from_cp->operands()->adr_at(0), new_ops->adr_at(0), len * sizeof(u2));
1726 to_cp->set_operands(new_ops);
1727 } else {
1728 int old_len = to_cp->operands()->length();
1729 int from_len = from_cp->operands()->length();
1730 int old_off = old_oplen * sizeof(u2);
1731 int from_off = from_oplen * sizeof(u2);
1732 // Use the metaspace for the destination constant pool
1733 Array<u2>* new_operands = MetadataFactory::new_array<u2>(loader_data, old_len + from_len, CHECK);
1734 int fillp = 0, len = 0;
1735 // first part of dest
1736 Copy::conjoint_memory_atomic(to_cp->operands()->adr_at(0),
1737 new_operands->adr_at(fillp),
1738 (len = old_off) * sizeof(u2));
1739 fillp += len;
1740 // first part of src
1741 Copy::conjoint_memory_atomic(from_cp->operands()->adr_at(0),
1742 new_operands->adr_at(fillp),
1743 (len = from_off) * sizeof(u2));
1744 fillp += len;
1745 // second part of dest
1746 Copy::conjoint_memory_atomic(to_cp->operands()->adr_at(old_off),
1747 new_operands->adr_at(fillp),
1748 (len = old_len - old_off) * sizeof(u2));
1749 fillp += len;
1750 // second part of src
1751 Copy::conjoint_memory_atomic(from_cp->operands()->adr_at(from_off),
1752 new_operands->adr_at(fillp),
1753 (len = from_len - from_off) * sizeof(u2));
1754 fillp += len;
1755 assert(fillp == new_operands->length(), "");
1756
1757 // Adjust indexes in the first part of the copied operands array.
1758 for (int j = 0; j < from_oplen; j++) {
1759 int offset = operand_offset_at(new_operands, old_oplen + j);
1760 assert(offset == operand_offset_at(from_cp->operands(), j), "correct copy");
1761 offset += old_len; // every new tuple is preceded by old_len extra u2's
1762 operand_offset_at_put(new_operands, old_oplen + j, offset);
1763 }
1764
1765 // replace target operands array with combined array
1766 to_cp->set_operands(new_operands);
1767 }
1768 }
1769 } // end copy_operands()
1770
1771
1772 // Copy this constant pool's entries at start_i to end_i (inclusive)
1773 // to the constant pool to_cp's entries starting at to_i. A total of
1774 // (end_i - start_i) + 1 entries are copied.
1775 void ConstantPool::copy_cp_to_impl(const constantPoolHandle& from_cp, int start_i, int end_i,
1776 const constantPoolHandle& to_cp, int to_i, TRAPS) {
1777
1778
1779 int dest_cpi = to_i; // leave original alone for debug purposes
1780
1781 for (int src_cpi = start_i; src_cpi <= end_i; /* see loop bottom */ ) {
1782 copy_entry_to(from_cp, src_cpi, to_cp, dest_cpi);
1783
1784 switch (from_cp->tag_at(src_cpi).value()) {
1785 case JVM_CONSTANT_Double:
1786 case JVM_CONSTANT_Long:
1787 // double and long take two constant pool entries
1788 src_cpi += 2;
1789 dest_cpi += 2;
1790 break;
1791
1792 default:
1793 // all others take one constant pool entry
1794 src_cpi++;
1795 dest_cpi++;
1796 break;
1797 }
1798 }
1799 copy_operands(from_cp, to_cp, CHECK);
1800
1801 } // end copy_cp_to_impl()
1802
1803
1804 // Copy this constant pool's entry at from_i to the constant pool
1805 // to_cp's entry at to_i.
1806 void ConstantPool::copy_entry_to(const constantPoolHandle& from_cp, int from_i,
1807 const constantPoolHandle& to_cp, int to_i) {
1808
1809 int tag = from_cp->tag_at(from_i).value();
1810 switch (tag) {
1811 case JVM_CONSTANT_ClassIndex:
1812 {
1813 jint ki = from_cp->klass_index_at(from_i);
1814 to_cp->klass_index_at_put(to_i, ki);
1815 } break;
1816
1817 case JVM_CONSTANT_Double:
1818 {
1819 jdouble d = from_cp->double_at(from_i);
1820 to_cp->double_at_put(to_i, d);
1821 // double takes two constant pool entries so init second entry's tag
1822 to_cp->tag_at_put(to_i + 1, JVM_CONSTANT_Invalid);
1823 } break;
1824
1825 case JVM_CONSTANT_Fieldref:
1826 {
1827 int class_index = from_cp->uncached_klass_ref_index_at(from_i);
1828 int name_and_type_index = from_cp->uncached_name_and_type_ref_index_at(from_i);
1829 to_cp->field_at_put(to_i, class_index, name_and_type_index);
1830 } break;
1831
1832 case JVM_CONSTANT_Float:
1833 {
1834 jfloat f = from_cp->float_at(from_i);
1835 to_cp->float_at_put(to_i, f);
1836 } break;
1837
1838 case JVM_CONSTANT_Integer:
1839 {
1840 jint i = from_cp->int_at(from_i);
1841 to_cp->int_at_put(to_i, i);
1842 } break;
1843
1844 case JVM_CONSTANT_InterfaceMethodref:
1845 {
1846 int class_index = from_cp->uncached_klass_ref_index_at(from_i);
1847 int name_and_type_index = from_cp->uncached_name_and_type_ref_index_at(from_i);
1848 to_cp->interface_method_at_put(to_i, class_index, name_and_type_index);
1849 } break;
1850
1851 case JVM_CONSTANT_Long:
1852 {
1853 jlong l = from_cp->long_at(from_i);
1854 to_cp->long_at_put(to_i, l);
1855 // long takes two constant pool entries so init second entry's tag
1856 to_cp->tag_at_put(to_i + 1, JVM_CONSTANT_Invalid);
1857 } break;
1858
1859 case JVM_CONSTANT_Methodref:
1860 {
1861 int class_index = from_cp->uncached_klass_ref_index_at(from_i);
1862 int name_and_type_index = from_cp->uncached_name_and_type_ref_index_at(from_i);
1863 to_cp->method_at_put(to_i, class_index, name_and_type_index);
1864 } break;
1865
1866 case JVM_CONSTANT_NameAndType:
1867 {
1868 int name_ref_index = from_cp->name_ref_index_at(from_i);
1869 int signature_ref_index = from_cp->signature_ref_index_at(from_i);
1870 to_cp->name_and_type_at_put(to_i, name_ref_index, signature_ref_index);
1871 } break;
1872
1873 case JVM_CONSTANT_StringIndex:
1874 {
1875 jint si = from_cp->string_index_at(from_i);
1876 to_cp->string_index_at_put(to_i, si);
1877 } break;
1878
1879 case JVM_CONSTANT_Class:
1880 case JVM_CONSTANT_UnresolvedClass:
1881 case JVM_CONSTANT_UnresolvedClassInError:
1882 {
1883 // Revert to JVM_CONSTANT_ClassIndex
1884 int name_index = from_cp->klass_slot_at(from_i).name_index();
1885 assert(from_cp->tag_at(name_index).is_symbol(), "sanity");
1886 to_cp->klass_index_at_put(to_i, name_index);
1887 } break;
1888
1889 case JVM_CONSTANT_String:
1890 {
1891 Symbol* s = from_cp->unresolved_string_at(from_i);
1892 to_cp->unresolved_string_at_put(to_i, s);
1893 } break;
1894
1895 case JVM_CONSTANT_Utf8:
1896 {
1897 Symbol* s = from_cp->symbol_at(from_i);
1898 // Need to increase refcount, the old one will be thrown away and deferenced
1899 s->increment_refcount();
1900 to_cp->symbol_at_put(to_i, s);
1901 } break;
1902
1903 case JVM_CONSTANT_MethodType:
1904 case JVM_CONSTANT_MethodTypeInError:
1905 {
1906 jint k = from_cp->method_type_index_at(from_i);
1907 to_cp->method_type_index_at_put(to_i, k);
1908 } break;
1909
1910 case JVM_CONSTANT_MethodHandle:
1911 case JVM_CONSTANT_MethodHandleInError:
1912 {
1913 int k1 = from_cp->method_handle_ref_kind_at(from_i);
1914 int k2 = from_cp->method_handle_index_at(from_i);
1915 to_cp->method_handle_index_at_put(to_i, k1, k2);
1916 } break;
1917
1918 case JVM_CONSTANT_Dynamic:
1919 case JVM_CONSTANT_DynamicInError:
1920 {
1921 int k1 = from_cp->bootstrap_methods_attribute_index(from_i);
1922 int k2 = from_cp->bootstrap_name_and_type_ref_index_at(from_i);
1923 k1 += operand_array_length(to_cp->operands()); // to_cp might already have operands
1924 to_cp->dynamic_constant_at_put(to_i, k1, k2);
1925 } break;
1926
1927 case JVM_CONSTANT_InvokeDynamic:
1928 {
1929 int k1 = from_cp->bootstrap_methods_attribute_index(from_i);
1930 int k2 = from_cp->bootstrap_name_and_type_ref_index_at(from_i);
1931 k1 += operand_array_length(to_cp->operands()); // to_cp might already have operands
1932 to_cp->invoke_dynamic_at_put(to_i, k1, k2);
1933 } break;
1934
1935 // Invalid is used as the tag for the second constant pool entry
1936 // occupied by JVM_CONSTANT_Double or JVM_CONSTANT_Long. It should
1937 // not be seen by itself.
1938 case JVM_CONSTANT_Invalid: // fall through
1939
1940 default:
1941 {
1942 ShouldNotReachHere();
1943 } break;
1944 }
1945 } // end copy_entry_to()
1946
1947 // Search constant pool search_cp for an entry that matches this
1948 // constant pool's entry at pattern_i. Returns the index of a
1949 // matching entry or zero (0) if there is no matching entry.
1950 int ConstantPool::find_matching_entry(int pattern_i,
1951 const constantPoolHandle& search_cp) {
1952
1953 // index zero (0) is not used
1954 for (int i = 1; i < search_cp->length(); i++) {
1955 bool found = compare_entry_to(pattern_i, search_cp, i);
1956 if (found) {
1957 return i;
1958 }
1959 }
1960
1961 return 0; // entry not found; return unused index zero (0)
1962 } // end find_matching_entry()
1963
1964
1965 // Compare this constant pool's bootstrap specifier at idx1 to the constant pool
1966 // cp2's bootstrap specifier at idx2.
1967 bool ConstantPool::compare_operand_to(int idx1, const constantPoolHandle& cp2, int idx2) {
1968 int k1 = operand_bootstrap_method_ref_index_at(idx1);
1969 int k2 = cp2->operand_bootstrap_method_ref_index_at(idx2);
1970 bool match = compare_entry_to(k1, cp2, k2);
1971
1972 if (!match) {
1973 return false;
1974 }
1975 int argc = operand_argument_count_at(idx1);
1976 if (argc == cp2->operand_argument_count_at(idx2)) {
1977 for (int j = 0; j < argc; j++) {
1978 k1 = operand_argument_index_at(idx1, j);
1979 k2 = cp2->operand_argument_index_at(idx2, j);
1980 match = compare_entry_to(k1, cp2, k2);
1981 if (!match) {
1982 return false;
1983 }
1984 }
1985 return true; // got through loop; all elements equal
1986 }
1987 return false;
1988 } // end compare_operand_to()
1989
1990 // Search constant pool search_cp for a bootstrap specifier that matches
1991 // this constant pool's bootstrap specifier data at pattern_i index.
1992 // Return the index of a matching bootstrap attribute record or (-1) if there is no match.
1993 int ConstantPool::find_matching_operand(int pattern_i,
1994 const constantPoolHandle& search_cp, int search_len) {
1995 for (int i = 0; i < search_len; i++) {
1996 bool found = compare_operand_to(pattern_i, search_cp, i);
1997 if (found) {
1998 return i;
1999 }
2000 }
2001 return -1; // bootstrap specifier data not found; return unused index (-1)
2002 } // end find_matching_operand()
2003
2004
2005 #ifndef PRODUCT
2006
2007 const char* ConstantPool::printable_name_at(int cp_index) {
2008
2009 constantTag tag = tag_at(cp_index);
2010
2011 if (tag.is_string()) {
2012 return string_at_noresolve(cp_index);
2013 } else if (tag.is_klass() || tag.is_unresolved_klass()) {
2014 return klass_name_at(cp_index)->as_C_string();
2015 } else if (tag.is_symbol()) {
2016 return symbol_at(cp_index)->as_C_string();
2017 }
2018 return "";
2019 }
2020
2021 #endif // PRODUCT
2022
2023
2024 // JVMTI GetConstantPool support
2025
2026 // For debugging of constant pool
2027 const bool debug_cpool = false;
2028
2029 #define DBG(code) do { if (debug_cpool) { (code); } } while(0)
2030
2031 static void print_cpool_bytes(jint cnt, u1 *bytes) {
2032 const char* WARN_MSG = "Must not be such entry!";
2033 jint size = 0;
2034 u2 idx1, idx2;
2035
2036 for (jint idx = 1; idx < cnt; idx++) {
2037 jint ent_size = 0;
2038 u1 tag = *bytes++;
2039 size++; // count tag
2040
2041 printf("const #%03d, tag: %02d ", idx, tag);
2042 switch(tag) {
2043 case JVM_CONSTANT_Invalid: {
2044 printf("Invalid");
2045 break;
2046 }
2047 case JVM_CONSTANT_Unicode: {
2048 printf("Unicode %s", WARN_MSG);
2049 break;
2050 }
2051 case JVM_CONSTANT_Utf8: {
2052 u2 len = Bytes::get_Java_u2(bytes);
2053 char str[128];
2054 if (len > 127) {
2055 len = 127;
2056 }
2057 strncpy(str, (char *) (bytes+2), len);
2058 str[len] = '\0';
2059 printf("Utf8 \"%s\"", str);
2060 ent_size = 2 + len;
2061 break;
2062 }
2063 case JVM_CONSTANT_Integer: {
2064 u4 val = Bytes::get_Java_u4(bytes);
2065 printf("int %d", *(int *) &val);
2066 ent_size = 4;
2067 break;
2068 }
2069 case JVM_CONSTANT_Float: {
2070 u4 val = Bytes::get_Java_u4(bytes);
2071 printf("float %5.3ff", *(float *) &val);
2072 ent_size = 4;
2073 break;
2074 }
2075 case JVM_CONSTANT_Long: {
2076 u8 val = Bytes::get_Java_u8(bytes);
2077 printf("long " INT64_FORMAT, (int64_t) *(jlong *) &val);
2078 ent_size = 8;
2079 idx++; // Long takes two cpool slots
2080 break;
2081 }
2082 case JVM_CONSTANT_Double: {
2083 u8 val = Bytes::get_Java_u8(bytes);
2084 printf("double %5.3fd", *(jdouble *)&val);
2085 ent_size = 8;
2086 idx++; // Double takes two cpool slots
2087 break;
2088 }
2089 case JVM_CONSTANT_Class: {
2090 idx1 = Bytes::get_Java_u2(bytes);
2091 printf("class #%03d", idx1);
2092 ent_size = 2;
2093 break;
2094 }
2095 case JVM_CONSTANT_String: {
2096 idx1 = Bytes::get_Java_u2(bytes);
2097 printf("String #%03d", idx1);
2098 ent_size = 2;
2099 break;
2100 }
2101 case JVM_CONSTANT_Fieldref: {
2102 idx1 = Bytes::get_Java_u2(bytes);
2103 idx2 = Bytes::get_Java_u2(bytes+2);
2104 printf("Field #%03d, #%03d", (int) idx1, (int) idx2);
2105 ent_size = 4;
2106 break;
2107 }
2108 case JVM_CONSTANT_Methodref: {
2109 idx1 = Bytes::get_Java_u2(bytes);
2110 idx2 = Bytes::get_Java_u2(bytes+2);
2111 printf("Method #%03d, #%03d", idx1, idx2);
2112 ent_size = 4;
2113 break;
2114 }
2115 case JVM_CONSTANT_InterfaceMethodref: {
2116 idx1 = Bytes::get_Java_u2(bytes);
2117 idx2 = Bytes::get_Java_u2(bytes+2);
2118 printf("InterfMethod #%03d, #%03d", idx1, idx2);
2119 ent_size = 4;
2120 break;
2121 }
2122 case JVM_CONSTANT_NameAndType: {
2123 idx1 = Bytes::get_Java_u2(bytes);
2124 idx2 = Bytes::get_Java_u2(bytes+2);
2125 printf("NameAndType #%03d, #%03d", idx1, idx2);
2126 ent_size = 4;
2127 break;
2128 }
2129 case JVM_CONSTANT_ClassIndex: {
2130 printf("ClassIndex %s", WARN_MSG);
2131 break;
2132 }
2133 case JVM_CONSTANT_UnresolvedClass: {
2134 printf("UnresolvedClass: %s", WARN_MSG);
2135 break;
2136 }
2137 case JVM_CONSTANT_UnresolvedClassInError: {
2138 printf("UnresolvedClassInErr: %s", WARN_MSG);
2139 break;
2140 }
2141 case JVM_CONSTANT_StringIndex: {
2142 printf("StringIndex: %s", WARN_MSG);
2143 break;
2144 }
2145 }
2146 printf(";\n");
2147 bytes += ent_size;
2148 size += ent_size;
2149 }
2150 printf("Cpool size: %d\n", size);
2151 fflush(nullptr);
2152 return;
2153 } /* end print_cpool_bytes */
2154
2155
2156 // Returns size of constant pool entry.
2157 jint ConstantPool::cpool_entry_size(jint idx) {
2158 switch(tag_at(idx).value()) {
2159 case JVM_CONSTANT_Invalid:
2160 case JVM_CONSTANT_Unicode:
2161 return 1;
2162
2163 case JVM_CONSTANT_Utf8:
2164 return 3 + symbol_at(idx)->utf8_length();
2165
2166 case JVM_CONSTANT_Class:
2167 case JVM_CONSTANT_String:
2168 case JVM_CONSTANT_ClassIndex:
2169 case JVM_CONSTANT_UnresolvedClass:
2170 case JVM_CONSTANT_UnresolvedClassInError:
2171 case JVM_CONSTANT_StringIndex:
2172 case JVM_CONSTANT_MethodType:
2173 case JVM_CONSTANT_MethodTypeInError:
2174 return 3;
2175
2176 case JVM_CONSTANT_MethodHandle:
2177 case JVM_CONSTANT_MethodHandleInError:
2178 return 4; //tag, ref_kind, ref_index
2179
2180 case JVM_CONSTANT_Integer:
2181 case JVM_CONSTANT_Float:
2182 case JVM_CONSTANT_Fieldref:
2183 case JVM_CONSTANT_Methodref:
2184 case JVM_CONSTANT_InterfaceMethodref:
2185 case JVM_CONSTANT_NameAndType:
2186 return 5;
2187
2188 case JVM_CONSTANT_Dynamic:
2189 case JVM_CONSTANT_DynamicInError:
2190 case JVM_CONSTANT_InvokeDynamic:
2191 // u1 tag, u2 bsm, u2 nt
2192 return 5;
2193
2194 case JVM_CONSTANT_Long:
2195 case JVM_CONSTANT_Double:
2196 return 9;
2197 }
2198 assert(false, "cpool_entry_size: Invalid constant pool entry tag");
2199 return 1;
2200 } /* end cpool_entry_size */
2201
2202
2203 // SymbolHash is used to find a constant pool index from a string.
2204 // This function fills in SymbolHashs, one for utf8s and one for
2205 // class names, returns size of the cpool raw bytes.
2206 jint ConstantPool::hash_entries_to(SymbolHash *symmap,
2207 SymbolHash *classmap) {
2208 jint size = 0;
2209
2210 for (u2 idx = 1; idx < length(); idx++) {
2211 u2 tag = tag_at(idx).value();
2212 size += cpool_entry_size(idx);
2213
2214 switch(tag) {
2215 case JVM_CONSTANT_Utf8: {
2216 Symbol* sym = symbol_at(idx);
2217 symmap->add_if_absent(sym, idx);
2218 DBG(printf("adding symbol entry %s = %d\n", sym->as_utf8(), idx));
2219 break;
2220 }
2221 case JVM_CONSTANT_Class:
2222 case JVM_CONSTANT_UnresolvedClass:
2223 case JVM_CONSTANT_UnresolvedClassInError: {
2224 Symbol* sym = klass_name_at(idx);
2225 classmap->add_if_absent(sym, idx);
2226 DBG(printf("adding class entry %s = %d\n", sym->as_utf8(), idx));
2227 break;
2228 }
2229 case JVM_CONSTANT_Long:
2230 case JVM_CONSTANT_Double: {
2231 idx++; // Both Long and Double take two cpool slots
2232 break;
2233 }
2234 }
2235 }
2236 return size;
2237 } /* end hash_utf8_entries_to */
2238
2239
2240 // Copy cpool bytes.
2241 // Returns:
2242 // 0, in case of OutOfMemoryError
2243 // -1, in case of internal error
2244 // > 0, count of the raw cpool bytes that have been copied
2245 int ConstantPool::copy_cpool_bytes(int cpool_size,
2246 SymbolHash* tbl,
2247 unsigned char *bytes) {
2248 u2 idx1, idx2;
2249 jint size = 0;
2250 jint cnt = length();
2251 unsigned char *start_bytes = bytes;
2252
2253 for (jint idx = 1; idx < cnt; idx++) {
2254 u1 tag = tag_at(idx).value();
2255 jint ent_size = cpool_entry_size(idx);
2256
2257 assert(size + ent_size <= cpool_size, "Size mismatch");
2258
2259 *bytes = tag;
2260 DBG(printf("#%03hd tag=%03hd, ", (short)idx, (short)tag));
2261 switch(tag) {
2262 case JVM_CONSTANT_Invalid: {
2263 DBG(printf("JVM_CONSTANT_Invalid"));
2264 break;
2265 }
2266 case JVM_CONSTANT_Unicode: {
2267 assert(false, "Wrong constant pool tag: JVM_CONSTANT_Unicode");
2268 DBG(printf("JVM_CONSTANT_Unicode"));
2269 break;
2270 }
2271 case JVM_CONSTANT_Utf8: {
2272 Symbol* sym = symbol_at(idx);
2273 char* str = sym->as_utf8();
2274 // Warning! It's crashing on x86 with len = sym->utf8_length()
2275 int len = (int) strlen(str);
2276 Bytes::put_Java_u2((address) (bytes+1), (u2) len);
2277 for (int i = 0; i < len; i++) {
2278 bytes[3+i] = (u1) str[i];
2279 }
2280 DBG(printf("JVM_CONSTANT_Utf8: %s ", str));
2281 break;
2282 }
2283 case JVM_CONSTANT_Integer: {
2284 jint val = int_at(idx);
2285 Bytes::put_Java_u4((address) (bytes+1), *(u4*)&val);
2286 break;
2287 }
2288 case JVM_CONSTANT_Float: {
2289 jfloat val = float_at(idx);
2290 Bytes::put_Java_u4((address) (bytes+1), *(u4*)&val);
2291 break;
2292 }
2293 case JVM_CONSTANT_Long: {
2294 jlong val = long_at(idx);
2295 Bytes::put_Java_u8((address) (bytes+1), *(u8*)&val);
2296 idx++; // Long takes two cpool slots
2297 break;
2298 }
2299 case JVM_CONSTANT_Double: {
2300 jdouble val = double_at(idx);
2301 Bytes::put_Java_u8((address) (bytes+1), *(u8*)&val);
2302 idx++; // Double takes two cpool slots
2303 break;
2304 }
2305 case JVM_CONSTANT_Class:
2306 case JVM_CONSTANT_UnresolvedClass:
2307 case JVM_CONSTANT_UnresolvedClassInError: {
2308 *bytes = JVM_CONSTANT_Class;
2309 Symbol* sym = klass_name_at(idx);
2310 idx1 = tbl->symbol_to_value(sym);
2311 assert(idx1 != 0, "Have not found a hashtable entry");
2312 Bytes::put_Java_u2((address) (bytes+1), idx1);
2313 DBG(printf("JVM_CONSTANT_Class: idx=#%03hd, %s", idx1, sym->as_utf8()));
2314 break;
2315 }
2316 case JVM_CONSTANT_String: {
2317 *bytes = JVM_CONSTANT_String;
2318 Symbol* sym = unresolved_string_at(idx);
2319 idx1 = tbl->symbol_to_value(sym);
2320 assert(idx1 != 0, "Have not found a hashtable entry");
2321 Bytes::put_Java_u2((address) (bytes+1), idx1);
2322 DBG(printf("JVM_CONSTANT_String: idx=#%03hd, %s", idx1, sym->as_utf8()));
2323 break;
2324 }
2325 case JVM_CONSTANT_Fieldref:
2326 case JVM_CONSTANT_Methodref:
2327 case JVM_CONSTANT_InterfaceMethodref: {
2328 idx1 = uncached_klass_ref_index_at(idx);
2329 idx2 = uncached_name_and_type_ref_index_at(idx);
2330 Bytes::put_Java_u2((address) (bytes+1), idx1);
2331 Bytes::put_Java_u2((address) (bytes+3), idx2);
2332 DBG(printf("JVM_CONSTANT_Methodref: %hd %hd", idx1, idx2));
2333 break;
2334 }
2335 case JVM_CONSTANT_NameAndType: {
2336 idx1 = name_ref_index_at(idx);
2337 idx2 = signature_ref_index_at(idx);
2338 Bytes::put_Java_u2((address) (bytes+1), idx1);
2339 Bytes::put_Java_u2((address) (bytes+3), idx2);
2340 DBG(printf("JVM_CONSTANT_NameAndType: %hd %hd", idx1, idx2));
2341 break;
2342 }
2343 case JVM_CONSTANT_ClassIndex: {
2344 *bytes = JVM_CONSTANT_Class;
2345 idx1 = checked_cast<u2>(klass_index_at(idx));
2346 Bytes::put_Java_u2((address) (bytes+1), idx1);
2347 DBG(printf("JVM_CONSTANT_ClassIndex: %hd", idx1));
2348 break;
2349 }
2350 case JVM_CONSTANT_StringIndex: {
2351 *bytes = JVM_CONSTANT_String;
2352 idx1 = checked_cast<u2>(string_index_at(idx));
2353 Bytes::put_Java_u2((address) (bytes+1), idx1);
2354 DBG(printf("JVM_CONSTANT_StringIndex: %hd", idx1));
2355 break;
2356 }
2357 case JVM_CONSTANT_MethodHandle:
2358 case JVM_CONSTANT_MethodHandleInError: {
2359 *bytes = JVM_CONSTANT_MethodHandle;
2360 int kind = method_handle_ref_kind_at(idx);
2361 idx1 = checked_cast<u2>(method_handle_index_at(idx));
2362 *(bytes+1) = (unsigned char) kind;
2363 Bytes::put_Java_u2((address) (bytes+2), idx1);
2364 DBG(printf("JVM_CONSTANT_MethodHandle: %d %hd", kind, idx1));
2365 break;
2366 }
2367 case JVM_CONSTANT_MethodType:
2368 case JVM_CONSTANT_MethodTypeInError: {
2369 *bytes = JVM_CONSTANT_MethodType;
2370 idx1 = checked_cast<u2>(method_type_index_at(idx));
2371 Bytes::put_Java_u2((address) (bytes+1), idx1);
2372 DBG(printf("JVM_CONSTANT_MethodType: %hd", idx1));
2373 break;
2374 }
2375 case JVM_CONSTANT_Dynamic:
2376 case JVM_CONSTANT_DynamicInError: {
2377 *bytes = tag;
2378 idx1 = extract_low_short_from_int(*int_at_addr(idx));
2379 idx2 = extract_high_short_from_int(*int_at_addr(idx));
2380 assert(idx2 == bootstrap_name_and_type_ref_index_at(idx), "correct half of u4");
2381 Bytes::put_Java_u2((address) (bytes+1), idx1);
2382 Bytes::put_Java_u2((address) (bytes+3), idx2);
2383 DBG(printf("JVM_CONSTANT_Dynamic: %hd %hd", idx1, idx2));
2384 break;
2385 }
2386 case JVM_CONSTANT_InvokeDynamic: {
2387 *bytes = tag;
2388 idx1 = extract_low_short_from_int(*int_at_addr(idx));
2389 idx2 = extract_high_short_from_int(*int_at_addr(idx));
2390 assert(idx2 == bootstrap_name_and_type_ref_index_at(idx), "correct half of u4");
2391 Bytes::put_Java_u2((address) (bytes+1), idx1);
2392 Bytes::put_Java_u2((address) (bytes+3), idx2);
2393 DBG(printf("JVM_CONSTANT_InvokeDynamic: %hd %hd", idx1, idx2));
2394 break;
2395 }
2396 }
2397 DBG(printf("\n"));
2398 bytes += ent_size;
2399 size += ent_size;
2400 }
2401 assert(size == cpool_size, "Size mismatch");
2402
2403 // Keep temporarily for debugging until it's stable.
2404 DBG(print_cpool_bytes(cnt, start_bytes));
2405 return (int)(bytes - start_bytes);
2406 } /* end copy_cpool_bytes */
2407
2408 #undef DBG
2409
2410 bool ConstantPool::is_maybe_on_stack() const {
2411 // This method uses the similar logic as nmethod::is_maybe_on_stack()
2412 if (!Continuations::enabled()) {
2413 return false;
2414 }
2415
2416 // If the condition below is true, it means that the nmethod was found to
2417 // be alive the previous completed marking cycle.
2418 return cache()->gc_epoch() >= CodeCache::previous_completed_gc_marking_cycle();
2419 }
2420
2421 // For redefinition, if any methods found in loom stack chunks, the gc_epoch is
2422 // recorded in their constant pool cache. The on_stack-ness of the constant pool controls whether
2423 // memory for the method is reclaimed.
2424 bool ConstantPool::on_stack() const {
2425 if ((_flags &_on_stack) != 0) {
2426 return true;
2427 }
2428
2429 if (_cache == nullptr) {
2430 return false;
2431 }
2432
2433 return is_maybe_on_stack();
2434 }
2435
2436 void ConstantPool::set_on_stack(const bool value) {
2437 if (value) {
2438 // Only record if it's not already set.
2439 if (!on_stack()) {
2440 assert(!is_shared(), "should always be set for shared constant pools");
2441 _flags |= _on_stack;
2442 MetadataOnStackMark::record(this);
2443 }
2444 } else {
2445 // Clearing is done single-threadedly.
2446 if (!is_shared()) {
2447 _flags &= (u2)(~_on_stack);
2448 }
2449 }
2450 }
2451
2452 // Printing
2453
2454 void ConstantPool::print_on(outputStream* st) const {
2455 assert(is_constantPool(), "must be constantPool");
2456 st->print_cr("%s", internal_name());
2457 if (flags() != 0) {
2458 st->print(" - flags: 0x%x", flags());
2459 if (has_preresolution()) st->print(" has_preresolution");
2460 if (on_stack()) st->print(" on_stack");
2461 st->cr();
2462 }
2463 if (pool_holder() != nullptr) {
2464 st->print_cr(" - holder: " PTR_FORMAT, p2i(pool_holder()));
2465 }
2466 st->print_cr(" - cache: " PTR_FORMAT, p2i(cache()));
2467 st->print_cr(" - resolved_references: " PTR_FORMAT, p2i(resolved_references_or_null()));
2468 st->print_cr(" - reference_map: " PTR_FORMAT, p2i(reference_map()));
2469 st->print_cr(" - resolved_klasses: " PTR_FORMAT, p2i(resolved_klasses()));
2470 st->print_cr(" - cp length: %d", length());
2471
2472 for (int index = 1; index < length(); index++) { // Index 0 is unused
2473 ((ConstantPool*)this)->print_entry_on(index, st);
2474 switch (tag_at(index).value()) {
2475 case JVM_CONSTANT_Long :
2476 case JVM_CONSTANT_Double :
2477 index++; // Skip entry following eigth-byte constant
2478 }
2479
2480 }
2481 st->cr();
2482 }
2483
2484 // Print one constant pool entry
2485 void ConstantPool::print_entry_on(const int cp_index, outputStream* st) {
2486 EXCEPTION_MARK;
2487 st->print(" - %3d : ", cp_index);
2488 tag_at(cp_index).print_on(st);
2489 st->print(" : ");
2490 switch (tag_at(cp_index).value()) {
2491 case JVM_CONSTANT_Class :
2492 { Klass* k = klass_at(cp_index, CATCH);
2493 guarantee(k != nullptr, "need klass");
2494 k->print_value_on(st);
2495 st->print(" {" PTR_FORMAT "}", p2i(k));
2496 }
2497 break;
2498 case JVM_CONSTANT_Fieldref :
2499 case JVM_CONSTANT_Methodref :
2500 case JVM_CONSTANT_InterfaceMethodref :
2501 st->print("klass_index=%d", uncached_klass_ref_index_at(cp_index));
2502 st->print(" name_and_type_index=%d", uncached_name_and_type_ref_index_at(cp_index));
2503 break;
2504 case JVM_CONSTANT_String :
2505 unresolved_string_at(cp_index)->print_value_on(st);
2506 break;
2507 case JVM_CONSTANT_Integer :
2508 st->print("%d", int_at(cp_index));
2509 break;
2510 case JVM_CONSTANT_Float :
2511 st->print("%f", float_at(cp_index));
2512 break;
2513 case JVM_CONSTANT_Long :
2514 st->print_jlong(long_at(cp_index));
2515 break;
2516 case JVM_CONSTANT_Double :
2517 st->print("%lf", double_at(cp_index));
2518 break;
2519 case JVM_CONSTANT_NameAndType :
2520 st->print("name_index=%d", name_ref_index_at(cp_index));
2521 st->print(" signature_index=%d", signature_ref_index_at(cp_index));
2522 break;
2523 case JVM_CONSTANT_Utf8 :
2524 symbol_at(cp_index)->print_value_on(st);
2525 break;
2526 case JVM_CONSTANT_ClassIndex: {
2527 int name_index = *int_at_addr(cp_index);
2528 st->print("klass_index=%d ", name_index);
2529 symbol_at(name_index)->print_value_on(st);
2530 }
2531 break;
2532 case JVM_CONSTANT_UnresolvedClass : // fall-through
2533 case JVM_CONSTANT_UnresolvedClassInError: {
2534 CPKlassSlot kslot = klass_slot_at(cp_index);
2535 int resolved_klass_index = kslot.resolved_klass_index();
2536 int name_index = kslot.name_index();
2537 assert(tag_at(name_index).is_symbol(), "sanity");
2538 symbol_at(name_index)->print_value_on(st);
2539 }
2540 break;
2541 case JVM_CONSTANT_MethodHandle :
2542 case JVM_CONSTANT_MethodHandleInError :
2543 st->print("ref_kind=%d", method_handle_ref_kind_at(cp_index));
2544 st->print(" ref_index=%d", method_handle_index_at(cp_index));
2545 break;
2546 case JVM_CONSTANT_MethodType :
2547 case JVM_CONSTANT_MethodTypeInError :
2548 st->print("signature_index=%d", method_type_index_at(cp_index));
2549 break;
2550 case JVM_CONSTANT_Dynamic :
2551 case JVM_CONSTANT_DynamicInError :
2552 {
2553 st->print("bootstrap_method_index=%d", bootstrap_method_ref_index_at(cp_index));
2554 st->print(" type_index=%d", bootstrap_name_and_type_ref_index_at(cp_index));
2555 int argc = bootstrap_argument_count_at(cp_index);
2556 if (argc > 0) {
2557 for (int arg_i = 0; arg_i < argc; arg_i++) {
2558 int arg = bootstrap_argument_index_at(cp_index, arg_i);
2559 st->print((arg_i == 0 ? " arguments={%d" : ", %d"), arg);
2560 }
2561 st->print("}");
2562 }
2563 }
2564 break;
2565 case JVM_CONSTANT_InvokeDynamic :
2566 {
2567 st->print("bootstrap_method_index=%d", bootstrap_method_ref_index_at(cp_index));
2568 st->print(" name_and_type_index=%d", bootstrap_name_and_type_ref_index_at(cp_index));
2569 int argc = bootstrap_argument_count_at(cp_index);
2570 if (argc > 0) {
2571 for (int arg_i = 0; arg_i < argc; arg_i++) {
2572 int arg = bootstrap_argument_index_at(cp_index, arg_i);
2573 st->print((arg_i == 0 ? " arguments={%d" : ", %d"), arg);
2574 }
2575 st->print("}");
2576 }
2577 }
2578 break;
2579 default:
2580 ShouldNotReachHere();
2581 break;
2582 }
2583 st->cr();
2584 }
2585
2586 void ConstantPool::print_value_on(outputStream* st) const {
2587 assert(is_constantPool(), "must be constantPool");
2588 st->print("constant pool [%d]", length());
2589 if (has_preresolution()) st->print("/preresolution");
2590 if (operands() != nullptr) st->print("/operands[%d]", operands()->length());
2591 print_address_on(st);
2592 if (pool_holder() != nullptr) {
2593 st->print(" for ");
2594 pool_holder()->print_value_on(st);
2595 bool extra = (pool_holder()->constants() != this);
2596 if (extra) st->print(" (extra)");
2597 }
2598 if (cache() != nullptr) {
2599 st->print(" cache=" PTR_FORMAT, p2i(cache()));
2600 }
2601 }
2602
2603 // Verification
2604
2605 void ConstantPool::verify_on(outputStream* st) {
2606 guarantee(is_constantPool(), "object must be constant pool");
2607 for (int i = 0; i< length(); i++) {
2608 constantTag tag = tag_at(i);
2609 if (tag.is_klass() || tag.is_unresolved_klass()) {
2610 guarantee(klass_name_at(i)->refcount() != 0, "should have nonzero reference count");
2611 } else if (tag.is_symbol()) {
2612 Symbol* entry = symbol_at(i);
2613 guarantee(entry->refcount() != 0, "should have nonzero reference count");
2614 } else if (tag.is_string()) {
2615 Symbol* entry = unresolved_string_at(i);
2616 guarantee(entry->refcount() != 0, "should have nonzero reference count");
2617 }
2618 }
2619 if (pool_holder() != nullptr) {
2620 // Note: pool_holder() can be null in temporary constant pools
2621 // used during constant pool merging
2622 guarantee(pool_holder()->is_klass(), "should be klass");
2623 }
2624 }