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/archiveBuilder.hpp"
28 #include "cds/archiveHeapLoader.hpp"
29 #include "cds/archiveHeapWriter.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 assert(resolved_reference_at(rr_index) != nullptr, "must exist");
298 function(rr_index);
299
300 // Save the BSM as well (sometimes the JIT looks up the BSM it for replay)
301 int indy_cp_index = rie->constant_pool_index();
302 int bsm_mh_cp_index = bootstrap_method_ref_index_at(indy_cp_index);
303 int bsm_rr_index = cp_to_object_index(bsm_mh_cp_index);
304 assert(resolved_reference_at(bsm_rr_index) != nullptr, "must exist");
305 function(bsm_rr_index);
306 }
307 }
308 }
309
310 Array<ResolvedMethodEntry>* method_entries = cache()->resolved_method_entries();
311 if (method_entries != nullptr) {
312 for (int i = 0; i < method_entries->length(); i++) {
313 ResolvedMethodEntry* rme = method_entries->adr_at(i);
314 if (rme->is_resolved(Bytecodes::_invokehandle) && rme->has_appendix() &&
315 cache()->can_archive_resolved_method(this, rme)) {
316 int rr_index = rme->resolved_references_index();
317 assert(resolved_reference_at(rr_index) != nullptr, "must exist");
318 function(rr_index);
319 }
320 }
321 }
322 }
323 }
324
325 // Returns the _resolved_reference array after removing unarchivable items from it.
326 // Returns null if this class is not supported, or _resolved_reference doesn't exist.
327 objArrayOop ConstantPool::prepare_resolved_references_for_archiving() {
328 if (_cache == nullptr) {
329 return nullptr; // nothing to do
330 }
331
332 InstanceKlass *ik = pool_holder();
333 if (!(ik->is_shared_boot_class() || ik->is_shared_platform_class() ||
334 ik->is_shared_app_class())) {
335 // Archiving resolved references for classes from non-builtin loaders
336 // is not yet supported.
337 return nullptr;
338 }
339
340 objArrayOop rr = resolved_references();
341 if (rr != nullptr) {
342 ResourceMark rm;
343 int rr_len = rr->length();
344 GrowableArray<bool> keep_resolved_refs(rr_len, rr_len, false);
345
346 ConstantPool* src_cp = ArchiveBuilder::current()->get_source_addr(this);
347 src_cp->iterate_archivable_resolved_references([&](int rr_index) {
348 keep_resolved_refs.at_put(rr_index, true);
349 });
350
351 objArrayOop scratch_rr = HeapShared::scratch_resolved_references(src_cp);
352 Array<u2>* ref_map = reference_map();
353 int ref_map_len = ref_map == nullptr ? 0 : ref_map->length();
354 for (int i = 0; i < rr_len; i++) {
355 oop obj = rr->obj_at(i);
356 scratch_rr->obj_at_put(i, nullptr);
357 if (obj != nullptr) {
358 if (i < ref_map_len) {
359 int index = object_to_cp_index(i);
360 if (tag_at(index).is_string()) {
361 assert(java_lang_String::is_instance(obj), "must be");
362 if (!ArchiveHeapWriter::is_string_too_large_to_archive(obj)) {
363 scratch_rr->obj_at_put(i, obj);
364 }
365 continue;
366 }
367 }
368
369 if (keep_resolved_refs.at(i)) {
370 scratch_rr->obj_at_put(i, obj);
371 }
372 }
373 }
374 return scratch_rr;
375 }
376 return rr;
377 }
378
379 void ConstantPool::find_required_hidden_classes() {
380 if (_cache == nullptr) {
381 return;
382 }
383
384 ClassLoaderData* loader_data = pool_holder()->class_loader_data();
385 if (loader_data == nullptr) {
386 // These are custom loader classes from the preimage
387 return;
388 }
389
390 if (!SystemDictionaryShared::is_builtin_loader(loader_data)) {
391 // Archiving resolved references for classes from non-builtin loaders
392 // is not yet supported.
393 return;
394 }
395
396 objArrayOop rr = resolved_references();
397 if (rr != nullptr) {
398 iterate_archivable_resolved_references([&](int rr_index) {
399 oop obj = rr->obj_at(rr_index);
400 HeapShared::find_required_hidden_classes_in_object(obj);
401 });
402 }
403 }
404
405 void ConstantPool::add_dumped_interned_strings() {
406 objArrayOop rr = resolved_references();
407 if (rr != nullptr) {
408 int rr_len = rr->length();
409 for (int i = 0; i < rr_len; i++) {
410 oop p = rr->obj_at(i);
411 if (java_lang_String::is_instance(p) &&
412 !ArchiveHeapWriter::is_string_too_large_to_archive(p)) {
413 HeapShared::add_to_dumped_interned_strings(p);
414 }
415 }
416 }
417 }
418 #endif
419
420 #if INCLUDE_CDS
421 // CDS support. Create a new resolved_references array.
422 void ConstantPool::restore_unshareable_info(TRAPS) {
423 if (!_pool_holder->is_linked() && !_pool_holder->is_rewritten()) {
424 return;
425 }
426 assert(is_constantPool(), "ensure C++ vtable is restored");
427 assert(on_stack(), "should always be set for shared constant pools");
428 assert(is_shared(), "should always be set for shared constant pools");
429 if (is_for_method_handle_intrinsic()) {
430 // See the same check in remove_unshareable_info() below.
431 assert(cache() == NULL, "must not have cpCache");
432 return;
433 }
434 assert(_cache != nullptr, "constant pool _cache should not be null");
435
436 // Only create the new resolved references array if it hasn't been attempted before
437 if (resolved_references() != nullptr) return;
438
439 if (vmClasses::Object_klass_loaded()) {
440 ClassLoaderData* loader_data = pool_holder()->class_loader_data();
441 #if INCLUDE_CDS_JAVA_HEAP
442 if (ArchiveHeapLoader::is_in_use() &&
443 _cache->archived_references() != nullptr) {
444 oop archived = _cache->archived_references();
445 // Create handle for the archived resolved reference array object
446 HandleMark hm(THREAD);
447 Handle refs_handle(THREAD, archived);
448 set_resolved_references(loader_data->add_handle(refs_handle));
449 _cache->clear_archived_references();
450 } else
451 #endif
452 {
453 // No mapped archived resolved reference array
454 // Recreate the object array and add to ClassLoaderData.
455 int map_length = resolved_reference_length();
456 if (map_length > 0) {
457 objArrayOop stom = oopFactory::new_objArray(vmClasses::Object_klass(), map_length, CHECK);
458 HandleMark hm(THREAD);
459 Handle refs_handle(THREAD, stom); // must handleize.
460 set_resolved_references(loader_data->add_handle(refs_handle));
461 }
462 }
463 }
464
465 if (CDSConfig::is_dumping_final_static_archive() && resolved_references() != nullptr) {
466 objArrayOop scratch_references = oopFactory::new_objArray(vmClasses::Object_klass(), resolved_references()->length(), CHECK);
467 HeapShared::add_scratch_resolved_references(this, scratch_references);
468 }
469 }
470
471 void ConstantPool::remove_unshareable_info() {
472 // Shared ConstantPools are in the RO region, so the _flags cannot be modified.
473 // The _on_stack flag is used to prevent ConstantPools from deallocation during
474 // class redefinition. Since shared ConstantPools cannot be deallocated anyway,
475 // we always set _on_stack to true to avoid having to change _flags during runtime.
476 _flags |= (_on_stack | _is_shared);
477
478 if (is_for_method_handle_intrinsic()) {
479 // This CP was created by Method::make_method_handle_intrinsic() and has nothing
480 // that need to be removed/restored. It has no cpCache since the intrinsic methods
481 // don't have any bytecodes.
482 assert(cache() == NULL, "must not have cpCache");
483 return;
484 }
485
486 // resolved_references(): remember its length. If it cannot be restored
487 // from the archived heap objects at run time, we need to dynamically allocate it.
488 if (cache() != nullptr) {
489 set_resolved_reference_length(
490 resolved_references() != nullptr ? resolved_references()->length() : 0);
491 set_resolved_references(OopHandle());
492 }
493 remove_unshareable_entries();
494 }
495
496 static const char* get_type(Klass* k) {
497 const char* type;
498 Klass* src_k;
499 if (ArchiveBuilder::is_active() && ArchiveBuilder::current()->is_in_buffer_space(k)) {
500 src_k = ArchiveBuilder::current()->get_source_addr(k);
501 } else {
502 src_k = k;
503 }
504
505 if (src_k->is_objArray_klass()) {
506 src_k = ObjArrayKlass::cast(src_k)->bottom_klass();
507 assert(!src_k->is_objArray_klass(), "sanity");
508 }
509
510 if (src_k->is_typeArray_klass()) {
511 type = "prim";
512 } else {
513 InstanceKlass* src_ik = InstanceKlass::cast(src_k);
514 if (CDSConfig::is_dumping_final_static_archive() && src_ik->class_loader_data() == nullptr) {
515 return "unreg";
516 }
517 oop loader = src_ik->class_loader();
518 if (loader == nullptr) {
519 type = "boot";
520 } else if (loader == SystemDictionary::java_platform_loader()) {
521 type = "plat";
522 } else if (loader == SystemDictionary::java_system_loader()) {
523 type = "app";
524 } else {
525 type = "unreg";
526 }
527 }
528
529 return type;
530 }
531
532 void ConstantPool::remove_unshareable_entries() {
533 ResourceMark rm;
534 log_info(cds, resolve)("Archiving CP entries for %s", pool_holder()->name()->as_C_string());
535 for (int cp_index = 1; cp_index < length(); cp_index++) { // cp_index 0 is unused
536 int cp_tag = tag_at(cp_index).value();
537 switch (cp_tag) {
538 case JVM_CONSTANT_UnresolvedClass:
539 ArchiveBuilder::alloc_stats()->record_klass_cp_entry(false, false);
540 break;
541 case JVM_CONSTANT_UnresolvedClassInError:
542 tag_at_put(cp_index, JVM_CONSTANT_UnresolvedClass);
543 ArchiveBuilder::alloc_stats()->record_klass_cp_entry(false, true);
544 break;
545 case JVM_CONSTANT_MethodHandleInError:
546 tag_at_put(cp_index, JVM_CONSTANT_MethodHandle);
547 break;
548 case JVM_CONSTANT_MethodTypeInError:
549 tag_at_put(cp_index, JVM_CONSTANT_MethodType);
550 break;
551 case JVM_CONSTANT_DynamicInError:
552 tag_at_put(cp_index, JVM_CONSTANT_Dynamic);
553 break;
554 case JVM_CONSTANT_Class:
555 remove_resolved_klass_if_non_deterministic(cp_index);
556 break;
557 default:
558 break;
559 }
560 }
561
562 if (cache() != nullptr) {
563 // cache() is null if this class is not yet linked.
564 cache()->remove_unshareable_info();
565 }
566 }
567
568 void ConstantPool::remove_resolved_klass_if_non_deterministic(int cp_index) {
569 assert(ArchiveBuilder::current()->is_in_buffer_space(this), "must be");
570 assert(tag_at(cp_index).is_klass(), "must be resolved");
571
572 Klass* k = resolved_klass_at(cp_index);
573 bool can_archive;
574
575 if (k == nullptr) {
576 // We'd come here if the referenced class has been excluded via
577 // SystemDictionaryShared::is_excluded_class(). As a result, ArchiveBuilder
578 // has cleared the resolved_klasses()->at(...) pointer to null. Thus, we
579 // need to revert the tag to JVM_CONSTANT_UnresolvedClass.
580 can_archive = false;
581 } else {
582 ConstantPool* src_cp = ArchiveBuilder::current()->get_source_addr(this);
583 can_archive = AOTConstantPoolResolver::is_resolution_deterministic(src_cp, cp_index);
584 }
585
586 if (!can_archive) {
587 int resolved_klass_index = klass_slot_at(cp_index).resolved_klass_index();
588 resolved_klasses()->at_put(resolved_klass_index, nullptr);
589 tag_at_put(cp_index, JVM_CONSTANT_UnresolvedClass);
590 }
591
592 LogStreamHandle(Trace, cds, resolve) log;
593 if (log.is_enabled()) {
594 ResourceMark rm;
595 log.print("%s klass CP entry [%3d]: %s %s",
596 (can_archive ? "archived" : "reverted"),
597 cp_index, pool_holder()->name()->as_C_string(), get_type(pool_holder()));
598 if (can_archive) {
599 log.print(" => %s %s%s", k->name()->as_C_string(), get_type(k),
600 (!k->is_instance_klass() || pool_holder()->is_subtype_of(k)) ? "" : " (not supertype)");
601 } else {
602 Symbol* name = klass_name_at(cp_index);
603 log.print(" => %s", name->as_C_string());
604 }
605 }
606
607 ArchiveBuilder::alloc_stats()->record_klass_cp_entry(can_archive, /*reverted=*/!can_archive);
608 }
609 #endif // INCLUDE_CDS
610
611 int ConstantPool::cp_to_object_index(int cp_index) {
612 // this is harder don't do this so much.
613 int i = reference_map()->find(checked_cast<u2>(cp_index));
614 // We might not find the index for jsr292 call.
615 return (i < 0) ? _no_index_sentinel : i;
616 }
617
618 void ConstantPool::string_at_put(int obj_index, oop str) {
619 oop result = set_resolved_reference_at(obj_index, str);
620 assert(result == nullptr || result == str, "Only set once or to the same string.");
621 }
622
623 void ConstantPool::trace_class_resolution(const constantPoolHandle& this_cp, Klass* k) {
624 ResourceMark rm;
625 int line_number = -1;
626 const char * source_file = nullptr;
627 if (JavaThread::current()->has_last_Java_frame()) {
628 // try to identify the method which called this function.
629 vframeStream vfst(JavaThread::current());
630 if (!vfst.at_end()) {
631 line_number = vfst.method()->line_number_from_bci(vfst.bci());
632 Symbol* s = vfst.method()->method_holder()->source_file_name();
633 if (s != nullptr) {
634 source_file = s->as_C_string();
635 }
636 }
637 }
638 if (k != this_cp->pool_holder()) {
639 // only print something if the classes are different
640 if (source_file != nullptr) {
641 log_debug(class, resolve)("%s %s %s:%d",
642 this_cp->pool_holder()->external_name(),
643 k->external_name(), source_file, line_number);
644 } else {
645 log_debug(class, resolve)("%s %s",
646 this_cp->pool_holder()->external_name(),
647 k->external_name());
648 }
649 }
650 }
651
652 Klass* ConstantPool::klass_at_impl(const constantPoolHandle& this_cp, int cp_index,
653 TRAPS) {
654 JavaThread* javaThread = THREAD;
655
656 // A resolved constantPool entry will contain a Klass*, otherwise a Symbol*.
657 // It is not safe to rely on the tag bit's here, since we don't have a lock, and
658 // the entry and tag is not updated atomically.
659 CPKlassSlot kslot = this_cp->klass_slot_at(cp_index);
660 int resolved_klass_index = kslot.resolved_klass_index();
661 int name_index = kslot.name_index();
662 assert(this_cp->tag_at(name_index).is_symbol(), "sanity");
663
664 // The tag must be JVM_CONSTANT_Class in order to read the correct value from
665 // the unresolved_klasses() array.
666 if (this_cp->tag_at(cp_index).is_klass()) {
667 Klass* klass = this_cp->resolved_klasses()->at(resolved_klass_index);
668 if (klass != nullptr) {
669 return klass;
670 }
671 }
672
673 // This tag doesn't change back to unresolved class unless at a safepoint.
674 if (this_cp->tag_at(cp_index).is_unresolved_klass_in_error()) {
675 // The original attempt to resolve this constant pool entry failed so find the
676 // class of the original error and throw another error of the same class
677 // (JVMS 5.4.3).
678 // If there is a detail message, pass that detail message to the error.
679 // The JVMS does not strictly require us to duplicate the same detail message,
680 // or any internal exception fields such as cause or stacktrace. But since the
681 // detail message is often a class name or other literal string, we will repeat it
682 // if we can find it in the symbol table.
683 throw_resolution_error(this_cp, cp_index, CHECK_NULL);
684 ShouldNotReachHere();
685 }
686
687 HandleMark hm(THREAD);
688 Handle mirror_handle;
689 Symbol* name = this_cp->symbol_at(name_index);
690 Handle loader (THREAD, this_cp->pool_holder()->class_loader());
691 Handle protection_domain (THREAD, this_cp->pool_holder()->protection_domain());
692
693 Klass* k;
694 {
695 // Turn off the single stepping while doing class resolution
696 JvmtiHideSingleStepping jhss(javaThread);
697 k = SystemDictionary::resolve_or_fail(name, loader, protection_domain, true, THREAD);
698 } // JvmtiHideSingleStepping jhss(javaThread);
699
700 if (!HAS_PENDING_EXCEPTION) {
701 // preserve the resolved klass from unloading
702 mirror_handle = Handle(THREAD, k->java_mirror());
703 // Do access check for klasses
704 verify_constant_pool_resolve(this_cp, k, THREAD);
705 }
706
707 // Failed to resolve class. We must record the errors so that subsequent attempts
708 // to resolve this constant pool entry fail with the same error (JVMS 5.4.3).
709 if (HAS_PENDING_EXCEPTION) {
710 save_and_throw_exception(this_cp, cp_index, constantTag(JVM_CONSTANT_UnresolvedClass), CHECK_NULL);
711 // If CHECK_NULL above doesn't return the exception, that means that
712 // some other thread has beaten us and has resolved the class.
713 // To preserve old behavior, we return the resolved class.
714 Klass* klass = this_cp->resolved_klasses()->at(resolved_klass_index);
715 assert(klass != nullptr, "must be resolved if exception was cleared");
716 return klass;
717 }
718
719 // logging for class+resolve.
720 if (log_is_enabled(Debug, class, resolve)){
721 trace_class_resolution(this_cp, k);
722 }
723
724 Klass** adr = this_cp->resolved_klasses()->adr_at(resolved_klass_index);
725 Atomic::release_store(adr, k);
726 // The interpreter assumes when the tag is stored, the klass is resolved
727 // and the Klass* stored in _resolved_klasses is non-null, so we need
728 // hardware store ordering here.
729 // We also need to CAS to not overwrite an error from a racing thread.
730
731 jbyte old_tag = Atomic::cmpxchg((jbyte*)this_cp->tag_addr_at(cp_index),
732 (jbyte)JVM_CONSTANT_UnresolvedClass,
733 (jbyte)JVM_CONSTANT_Class);
734
735 // We need to recheck exceptions from racing thread and return the same.
736 if (old_tag == JVM_CONSTANT_UnresolvedClassInError) {
737 // Remove klass.
738 this_cp->resolved_klasses()->at_put(resolved_klass_index, nullptr);
739 throw_resolution_error(this_cp, cp_index, CHECK_NULL);
740 }
741
742 return k;
743 }
744
745
746 // Does not update ConstantPool* - to avoid any exception throwing. Used
747 // by compiler and exception handling. Also used to avoid classloads for
748 // instanceof operations. Returns null if the class has not been loaded or
749 // if the verification of constant pool failed
750 Klass* ConstantPool::klass_at_if_loaded(const constantPoolHandle& this_cp, int which) {
751 CPKlassSlot kslot = this_cp->klass_slot_at(which);
752 int resolved_klass_index = kslot.resolved_klass_index();
753 int name_index = kslot.name_index();
754 assert(this_cp->tag_at(name_index).is_symbol(), "sanity");
755
756 if (this_cp->tag_at(which).is_klass()) {
757 Klass* k = this_cp->resolved_klasses()->at(resolved_klass_index);
758 assert(k != nullptr, "should be resolved");
759 return k;
760 } else if (this_cp->tag_at(which).is_unresolved_klass_in_error()) {
761 return nullptr;
762 } else {
763 Thread* current = Thread::current();
764 HandleMark hm(current);
765 Symbol* name = this_cp->symbol_at(name_index);
766 oop loader = this_cp->pool_holder()->class_loader();
767 oop protection_domain = this_cp->pool_holder()->protection_domain();
768 Handle h_prot (current, protection_domain);
769 Handle h_loader (current, loader);
770 Klass* k = SystemDictionary::find_instance_klass(current, name, h_loader, h_prot);
771
772 // Avoid constant pool verification at a safepoint, as it takes the Module_lock.
773 if (k != nullptr && current->is_Java_thread()) {
774 // Make sure that resolving is legal
775 JavaThread* THREAD = JavaThread::cast(current); // For exception macros.
776 ExceptionMark em(THREAD);
777 // return null if verification fails
778 verify_constant_pool_resolve(this_cp, k, THREAD);
779 if (HAS_PENDING_EXCEPTION) {
780 CLEAR_PENDING_EXCEPTION;
781 return nullptr;
782 }
783 return k;
784 } else {
785 return k;
786 }
787 }
788 }
789
790 Method* ConstantPool::method_at_if_loaded(const constantPoolHandle& cpool,
791 int which) {
792 if (cpool->cache() == nullptr) return nullptr; // nothing to load yet
793 if (!(which >= 0 && which < cpool->resolved_method_entries_length())) {
794 // FIXME: should be an assert
795 log_debug(class, resolve)("bad operand %d in:", which); cpool->print();
796 return nullptr;
797 }
798 return cpool->cache()->method_if_resolved(which);
799 }
800
801
802 bool ConstantPool::has_appendix_at_if_loaded(const constantPoolHandle& cpool, int which, Bytecodes::Code code) {
803 if (cpool->cache() == nullptr) return false; // nothing to load yet
804 if (code == Bytecodes::_invokedynamic) {
805 return cpool->resolved_indy_entry_at(which)->has_appendix();
806 } else {
807 return cpool->resolved_method_entry_at(which)->has_appendix();
808 }
809 }
810
811 oop ConstantPool::appendix_at_if_loaded(const constantPoolHandle& cpool, int which, Bytecodes::Code code) {
812 if (cpool->cache() == nullptr) return nullptr; // nothing to load yet
813 if (code == Bytecodes::_invokedynamic) {
814 return cpool->resolved_reference_from_indy(which);
815 } else {
816 return cpool->cache()->appendix_if_resolved(which);
817 }
818 }
819
820
821 bool ConstantPool::has_local_signature_at_if_loaded(const constantPoolHandle& cpool, int which, Bytecodes::Code code) {
822 if (cpool->cache() == nullptr) return false; // nothing to load yet
823 if (code == Bytecodes::_invokedynamic) {
824 return cpool->resolved_indy_entry_at(which)->has_local_signature();
825 } else {
826 return cpool->resolved_method_entry_at(which)->has_local_signature();
827 }
828 }
829
830 // Translate index, which could be CPCache index or Indy index, to a constant pool index
831 int ConstantPool::to_cp_index(int index, Bytecodes::Code code) {
832 assert(cache() != nullptr, "'index' is a rewritten index so this class must have been rewritten");
833 switch(code) {
834 case Bytecodes::_invokedynamic:
835 return invokedynamic_bootstrap_ref_index_at(index);
836 case Bytecodes::_getfield:
837 case Bytecodes::_getstatic:
838 case Bytecodes::_putfield:
839 case Bytecodes::_putstatic:
840 return resolved_field_entry_at(index)->constant_pool_index();
841 case Bytecodes::_invokeinterface:
842 case Bytecodes::_invokehandle:
843 case Bytecodes::_invokespecial:
844 case Bytecodes::_invokestatic:
845 case Bytecodes::_invokevirtual:
846 case Bytecodes::_fast_invokevfinal: // Bytecode interpreter uses this
847 return resolved_method_entry_at(index)->constant_pool_index();
848 default:
849 fatal("Unexpected bytecode: %s", Bytecodes::name(code));
850 }
851 }
852
853 bool ConstantPool::is_resolved(int index, Bytecodes::Code code) {
854 assert(cache() != nullptr, "'index' is a rewritten index so this class must have been rewritten");
855 switch(code) {
856 case Bytecodes::_invokedynamic:
857 return resolved_indy_entry_at(index)->is_resolved();
858
859 case Bytecodes::_getfield:
860 case Bytecodes::_getstatic:
861 case Bytecodes::_putfield:
862 case Bytecodes::_putstatic:
863 return resolved_field_entry_at(index)->is_resolved(code);
864
865 case Bytecodes::_invokeinterface:
866 case Bytecodes::_invokehandle:
867 case Bytecodes::_invokespecial:
868 case Bytecodes::_invokestatic:
869 case Bytecodes::_invokevirtual:
870 case Bytecodes::_fast_invokevfinal: // Bytecode interpreter uses this
871 return resolved_method_entry_at(index)->is_resolved(code);
872
873 default:
874 fatal("Unexpected bytecode: %s", Bytecodes::name(code));
875 }
876 }
877
878 u2 ConstantPool::uncached_name_and_type_ref_index_at(int cp_index) {
879 if (tag_at(cp_index).has_bootstrap()) {
880 u2 pool_index = bootstrap_name_and_type_ref_index_at(cp_index);
881 assert(tag_at(pool_index).is_name_and_type(), "");
882 return pool_index;
883 }
884 assert(tag_at(cp_index).is_field_or_method(), "Corrupted constant pool");
885 assert(!tag_at(cp_index).has_bootstrap(), "Must be handled above");
886 jint ref_index = *int_at_addr(cp_index);
887 return extract_high_short_from_int(ref_index);
888 }
889
890 u2 ConstantPool::name_and_type_ref_index_at(int index, Bytecodes::Code code) {
891 return uncached_name_and_type_ref_index_at(to_cp_index(index, code));
892 }
893
894 constantTag ConstantPool::tag_ref_at(int which, Bytecodes::Code code) {
895 // which may be either a Constant Pool index or a rewritten index
896 int pool_index = which;
897 assert(cache() != nullptr, "'index' is a rewritten index so this class must have been rewritten");
898 pool_index = to_cp_index(which, code);
899 return tag_at(pool_index);
900 }
901
902 u2 ConstantPool::uncached_klass_ref_index_at(int cp_index) {
903 assert(tag_at(cp_index).is_field_or_method(), "Corrupted constant pool");
904 jint ref_index = *int_at_addr(cp_index);
905 return extract_low_short_from_int(ref_index);
906 }
907
908 u2 ConstantPool::klass_ref_index_at(int index, Bytecodes::Code code) {
909 assert(code != Bytecodes::_invokedynamic,
910 "an invokedynamic instruction does not have a klass");
911 return uncached_klass_ref_index_at(to_cp_index(index, code));
912 }
913
914 void ConstantPool::verify_constant_pool_resolve(const constantPoolHandle& this_cp, Klass* k, TRAPS) {
915 if (!(k->is_instance_klass() || k->is_objArray_klass())) {
916 return; // short cut, typeArray klass is always accessible
917 }
918 Klass* holder = this_cp->pool_holder();
919 LinkResolver::check_klass_accessibility(holder, k, CHECK);
920 }
921
922
923 u2 ConstantPool::name_ref_index_at(int cp_index) {
924 jint ref_index = name_and_type_at(cp_index);
925 return extract_low_short_from_int(ref_index);
926 }
927
928
929 u2 ConstantPool::signature_ref_index_at(int cp_index) {
930 jint ref_index = name_and_type_at(cp_index);
931 return extract_high_short_from_int(ref_index);
932 }
933
934
935 Klass* ConstantPool::klass_ref_at(int which, Bytecodes::Code code, TRAPS) {
936 return klass_at(klass_ref_index_at(which, code), THREAD);
937 }
938
939 Symbol* ConstantPool::klass_name_at(int cp_index) const {
940 return symbol_at(klass_slot_at(cp_index).name_index());
941 }
942
943 Symbol* ConstantPool::klass_ref_at_noresolve(int which, Bytecodes::Code code) {
944 jint ref_index = klass_ref_index_at(which, code);
945 return klass_at_noresolve(ref_index);
946 }
947
948 Symbol* ConstantPool::uncached_klass_ref_at_noresolve(int cp_index) {
949 jint ref_index = uncached_klass_ref_index_at(cp_index);
950 return klass_at_noresolve(ref_index);
951 }
952
953 char* ConstantPool::string_at_noresolve(int cp_index) {
954 return unresolved_string_at(cp_index)->as_C_string();
955 }
956
957 BasicType ConstantPool::basic_type_for_signature_at(int cp_index) const {
958 return Signature::basic_type(symbol_at(cp_index));
959 }
960
961
962 void ConstantPool::resolve_string_constants_impl(const constantPoolHandle& this_cp, TRAPS) {
963 for (int index = 1; index < this_cp->length(); index++) { // Index 0 is unused
964 if (this_cp->tag_at(index).is_string()) {
965 this_cp->string_at(index, CHECK);
966 }
967 }
968 }
969
970 static const char* exception_message(const constantPoolHandle& this_cp, int which, constantTag tag, oop pending_exception) {
971 // Note: caller needs ResourceMark
972
973 // Dig out the detailed message to reuse if possible
974 const char* msg = java_lang_Throwable::message_as_utf8(pending_exception);
975 if (msg != nullptr) {
976 return msg;
977 }
978
979 Symbol* message = nullptr;
980 // Return specific message for the tag
981 switch (tag.value()) {
982 case JVM_CONSTANT_UnresolvedClass:
983 // return the class name in the error message
984 message = this_cp->klass_name_at(which);
985 break;
986 case JVM_CONSTANT_MethodHandle:
987 // return the method handle name in the error message
988 message = this_cp->method_handle_name_ref_at(which);
989 break;
990 case JVM_CONSTANT_MethodType:
991 // return the method type signature in the error message
992 message = this_cp->method_type_signature_at(which);
993 break;
994 case JVM_CONSTANT_Dynamic:
995 // return the name of the condy in the error message
996 message = this_cp->uncached_name_ref_at(which);
997 break;
998 default:
999 ShouldNotReachHere();
1000 }
1001
1002 return message != nullptr ? message->as_C_string() : nullptr;
1003 }
1004
1005 static void add_resolution_error(JavaThread* current, const constantPoolHandle& this_cp, int which,
1006 constantTag tag, oop pending_exception) {
1007
1008 ResourceMark rm(current);
1009 Symbol* error = pending_exception->klass()->name();
1010 oop cause = java_lang_Throwable::cause(pending_exception);
1011
1012 // Also dig out the exception cause, if present.
1013 Symbol* cause_sym = nullptr;
1014 const char* cause_msg = nullptr;
1015 if (cause != nullptr && cause != pending_exception) {
1016 cause_sym = cause->klass()->name();
1017 cause_msg = java_lang_Throwable::message_as_utf8(cause);
1018 }
1019
1020 const char* message = exception_message(this_cp, which, tag, pending_exception);
1021 SystemDictionary::add_resolution_error(this_cp, which, error, message, cause_sym, cause_msg);
1022 }
1023
1024
1025 void ConstantPool::throw_resolution_error(const constantPoolHandle& this_cp, int which, TRAPS) {
1026 ResourceMark rm(THREAD);
1027 const char* message = nullptr;
1028 Symbol* cause = nullptr;
1029 const char* cause_msg = nullptr;
1030 Symbol* error = SystemDictionary::find_resolution_error(this_cp, which, &message, &cause, &cause_msg);
1031 assert(error != nullptr, "checking");
1032
1033 CLEAR_PENDING_EXCEPTION;
1034 if (message != nullptr) {
1035 if (cause != nullptr) {
1036 Handle h_cause = Exceptions::new_exception(THREAD, cause, cause_msg);
1037 THROW_MSG_CAUSE(error, message, h_cause);
1038 } else {
1039 THROW_MSG(error, message);
1040 }
1041 } else {
1042 if (cause != nullptr) {
1043 Handle h_cause = Exceptions::new_exception(THREAD, cause, cause_msg);
1044 THROW_CAUSE(error, h_cause);
1045 } else {
1046 THROW(error);
1047 }
1048 }
1049 }
1050
1051 // If resolution for Class, Dynamic constant, MethodHandle or MethodType fails, save the
1052 // exception in the resolution error table, so that the same exception is thrown again.
1053 void ConstantPool::save_and_throw_exception(const constantPoolHandle& this_cp, int cp_index,
1054 constantTag tag, TRAPS) {
1055
1056 int error_tag = tag.error_value();
1057
1058 if (!PENDING_EXCEPTION->
1059 is_a(vmClasses::LinkageError_klass())) {
1060 // Just throw the exception and don't prevent these classes from
1061 // being loaded due to virtual machine errors like StackOverflow
1062 // and OutOfMemoryError, etc, or if the thread was hit by stop()
1063 // Needs clarification to section 5.4.3 of the VM spec (see 6308271)
1064 } else if (this_cp->tag_at(cp_index).value() != error_tag) {
1065 add_resolution_error(THREAD, this_cp, cp_index, tag, PENDING_EXCEPTION);
1066 // CAS in the tag. If a thread beat us to registering this error that's fine.
1067 // If another thread resolved the reference, this is a race condition. This
1068 // thread may have had a security manager or something temporary.
1069 // This doesn't deterministically get an error. So why do we save this?
1070 // We save this because jvmti can add classes to the bootclass path after
1071 // this error, so it needs to get the same error if the error is first.
1072 jbyte old_tag = Atomic::cmpxchg((jbyte*)this_cp->tag_addr_at(cp_index),
1073 (jbyte)tag.value(),
1074 (jbyte)error_tag);
1075 if (old_tag != error_tag && old_tag != tag.value()) {
1076 // MethodHandles and MethodType doesn't change to resolved version.
1077 assert(this_cp->tag_at(cp_index).is_klass(), "Wrong tag value");
1078 // Forget the exception and use the resolved class.
1079 CLEAR_PENDING_EXCEPTION;
1080 }
1081 } else {
1082 // some other thread put this in error state
1083 throw_resolution_error(this_cp, cp_index, CHECK);
1084 }
1085 }
1086
1087 constantTag ConstantPool::constant_tag_at(int cp_index) {
1088 constantTag tag = tag_at(cp_index);
1089 if (tag.is_dynamic_constant()) {
1090 BasicType bt = basic_type_for_constant_at(cp_index);
1091 return constantTag(constantTag::type2tag(bt));
1092 }
1093 return tag;
1094 }
1095
1096 BasicType ConstantPool::basic_type_for_constant_at(int cp_index) {
1097 constantTag tag = tag_at(cp_index);
1098 if (tag.is_dynamic_constant() ||
1099 tag.is_dynamic_constant_in_error()) {
1100 // have to look at the signature for this one
1101 Symbol* constant_type = uncached_signature_ref_at(cp_index);
1102 return Signature::basic_type(constant_type);
1103 }
1104 return tag.basic_type();
1105 }
1106
1107 // Called to resolve constants in the constant pool and return an oop.
1108 // Some constant pool entries cache their resolved oop. This is also
1109 // called to create oops from constants to use in arguments for invokedynamic
1110 oop ConstantPool::resolve_constant_at_impl(const constantPoolHandle& this_cp,
1111 int cp_index, int cache_index,
1112 bool* status_return, TRAPS) {
1113 oop result_oop = nullptr;
1114
1115 if (cache_index == _possible_index_sentinel) {
1116 // It is possible that this constant is one which is cached in the objects.
1117 // We'll do a linear search. This should be OK because this usage is rare.
1118 // FIXME: If bootstrap specifiers stress this code, consider putting in
1119 // a reverse index. Binary search over a short array should do it.
1120 assert(cp_index > 0, "valid constant pool index");
1121 cache_index = this_cp->cp_to_object_index(cp_index);
1122 }
1123 assert(cache_index == _no_index_sentinel || cache_index >= 0, "");
1124 assert(cp_index == _no_index_sentinel || cp_index >= 0, "");
1125
1126 if (cache_index >= 0) {
1127 result_oop = this_cp->resolved_reference_at(cache_index);
1128 if (result_oop != nullptr) {
1129 if (result_oop == Universe::the_null_sentinel()) {
1130 DEBUG_ONLY(int temp_index = (cp_index >= 0 ? cp_index : this_cp->object_to_cp_index(cache_index)));
1131 assert(this_cp->tag_at(temp_index).is_dynamic_constant(), "only condy uses the null sentinel");
1132 result_oop = nullptr;
1133 }
1134 if (status_return != nullptr) (*status_return) = true;
1135 return result_oop;
1136 // That was easy...
1137 }
1138 cp_index = this_cp->object_to_cp_index(cache_index);
1139 }
1140
1141 jvalue prim_value; // temp used only in a few cases below
1142
1143 constantTag tag = this_cp->tag_at(cp_index);
1144
1145 if (status_return != nullptr) {
1146 // don't trigger resolution if the constant might need it
1147 switch (tag.value()) {
1148 case JVM_CONSTANT_Class:
1149 {
1150 CPKlassSlot kslot = this_cp->klass_slot_at(cp_index);
1151 int resolved_klass_index = kslot.resolved_klass_index();
1152 if (this_cp->resolved_klasses()->at(resolved_klass_index) == nullptr) {
1153 (*status_return) = false;
1154 return nullptr;
1155 }
1156 // the klass is waiting in the CP; go get it
1157 break;
1158 }
1159 case JVM_CONSTANT_String:
1160 case JVM_CONSTANT_Integer:
1161 case JVM_CONSTANT_Float:
1162 case JVM_CONSTANT_Long:
1163 case JVM_CONSTANT_Double:
1164 // these guys trigger OOM at worst
1165 break;
1166 default:
1167 (*status_return) = false;
1168 return nullptr;
1169 }
1170 // from now on there is either success or an OOME
1171 (*status_return) = true;
1172 }
1173
1174 switch (tag.value()) {
1175
1176 case JVM_CONSTANT_UnresolvedClass:
1177 case JVM_CONSTANT_Class:
1178 {
1179 assert(cache_index == _no_index_sentinel, "should not have been set");
1180 Klass* resolved = klass_at_impl(this_cp, cp_index, CHECK_NULL);
1181 // ldc wants the java mirror.
1182 result_oop = resolved->java_mirror();
1183 break;
1184 }
1185
1186 case JVM_CONSTANT_Dynamic:
1187 { PerfTraceTimedEvent timer(ClassLoader::perf_resolve_invokedynamic_time(),
1188 ClassLoader::perf_resolve_invokedynamic_count());
1189
1190 // Resolve the Dynamically-Computed constant to invoke the BSM in order to obtain the resulting oop.
1191 BootstrapInfo bootstrap_specifier(this_cp, cp_index);
1192
1193 // The initial step in resolving an unresolved symbolic reference to a
1194 // dynamically-computed constant is to resolve the symbolic reference to a
1195 // method handle which will be the bootstrap method for the dynamically-computed
1196 // constant. If resolution of the java.lang.invoke.MethodHandle for the bootstrap
1197 // method fails, then a MethodHandleInError is stored at the corresponding
1198 // bootstrap method's CP index for the CONSTANT_MethodHandle_info. No need to
1199 // set a DynamicConstantInError here since any subsequent use of this
1200 // bootstrap method will encounter the resolution of MethodHandleInError.
1201 // Both the first, (resolution of the BSM and its static arguments), and the second tasks,
1202 // (invocation of the BSM), of JVMS Section 5.4.3.6 occur within invoke_bootstrap_method()
1203 // for the bootstrap_specifier created above.
1204 SystemDictionary::invoke_bootstrap_method(bootstrap_specifier, THREAD);
1205 Exceptions::wrap_dynamic_exception(/* is_indy */ false, THREAD);
1206 if (HAS_PENDING_EXCEPTION) {
1207 // Resolution failure of the dynamically-computed constant, save_and_throw_exception
1208 // will check for a LinkageError and store a DynamicConstantInError.
1209 save_and_throw_exception(this_cp, cp_index, tag, CHECK_NULL);
1210 }
1211 result_oop = bootstrap_specifier.resolved_value()();
1212 BasicType type = Signature::basic_type(bootstrap_specifier.signature());
1213 if (!is_reference_type(type)) {
1214 // Make sure the primitive value is properly boxed.
1215 // This is a JDK responsibility.
1216 const char* fail = nullptr;
1217 if (result_oop == nullptr) {
1218 fail = "null result instead of box";
1219 } else if (!is_java_primitive(type)) {
1220 // FIXME: support value types via unboxing
1221 fail = "can only handle references and primitives";
1222 } else if (!java_lang_boxing_object::is_instance(result_oop, type)) {
1223 fail = "primitive is not properly boxed";
1224 }
1225 if (fail != nullptr) {
1226 // Since this exception is not a LinkageError, throw exception
1227 // but do not save a DynamicInError resolution result.
1228 // See section 5.4.3 of the VM spec.
1229 THROW_MSG_NULL(vmSymbols::java_lang_InternalError(), fail);
1230 }
1231 }
1232
1233 LogTarget(Debug, methodhandles, condy) lt_condy;
1234 if (lt_condy.is_enabled()) {
1235 LogStream ls(lt_condy);
1236 bootstrap_specifier.print_msg_on(&ls, "resolve_constant_at_impl");
1237 }
1238 break;
1239 }
1240
1241 case JVM_CONSTANT_String:
1242 assert(cache_index != _no_index_sentinel, "should have been set");
1243 result_oop = string_at_impl(this_cp, cp_index, cache_index, CHECK_NULL);
1244 break;
1245
1246 case JVM_CONSTANT_MethodHandle:
1247 { PerfTraceTimedEvent timer(ClassLoader::perf_resolve_method_handle_time(),
1248 ClassLoader::perf_resolve_method_handle_count());
1249
1250 int ref_kind = this_cp->method_handle_ref_kind_at(cp_index);
1251 int callee_index = this_cp->method_handle_klass_index_at(cp_index);
1252 Symbol* name = this_cp->method_handle_name_ref_at(cp_index);
1253 Symbol* signature = this_cp->method_handle_signature_ref_at(cp_index);
1254 constantTag m_tag = this_cp->tag_at(this_cp->method_handle_index_at(cp_index));
1255 { ResourceMark rm(THREAD);
1256 log_debug(class, resolve)("resolve JVM_CONSTANT_MethodHandle:%d [%d/%d/%d] %s.%s",
1257 ref_kind, cp_index, this_cp->method_handle_index_at(cp_index),
1258 callee_index, name->as_C_string(), signature->as_C_string());
1259 }
1260
1261 Klass* callee = klass_at_impl(this_cp, callee_index, THREAD);
1262 if (HAS_PENDING_EXCEPTION) {
1263 save_and_throw_exception(this_cp, cp_index, tag, CHECK_NULL);
1264 }
1265
1266 // Check constant pool method consistency
1267 if ((callee->is_interface() && m_tag.is_method()) ||
1268 (!callee->is_interface() && m_tag.is_interface_method())) {
1269 ResourceMark rm(THREAD);
1270 stringStream ss;
1271 ss.print("Inconsistent constant pool data in classfile for class %s. "
1272 "Method '", callee->name()->as_C_string());
1273 signature->print_as_signature_external_return_type(&ss);
1274 ss.print(" %s(", name->as_C_string());
1275 signature->print_as_signature_external_parameters(&ss);
1276 ss.print(")' at index %d is %s and should be %s",
1277 cp_index,
1278 callee->is_interface() ? "CONSTANT_MethodRef" : "CONSTANT_InterfaceMethodRef",
1279 callee->is_interface() ? "CONSTANT_InterfaceMethodRef" : "CONSTANT_MethodRef");
1280 Exceptions::fthrow(THREAD_AND_LOCATION, vmSymbols::java_lang_IncompatibleClassChangeError(), "%s", ss.as_string());
1281 save_and_throw_exception(this_cp, cp_index, tag, CHECK_NULL);
1282 }
1283
1284 Klass* klass = this_cp->pool_holder();
1285 HandleMark hm(THREAD);
1286 Handle value = SystemDictionary::link_method_handle_constant(klass, ref_kind,
1287 callee, name, signature,
1288 THREAD);
1289 if (HAS_PENDING_EXCEPTION) {
1290 save_and_throw_exception(this_cp, cp_index, tag, CHECK_NULL);
1291 }
1292 result_oop = value();
1293 break;
1294 }
1295
1296 case JVM_CONSTANT_MethodType:
1297 { PerfTraceTimedEvent timer(ClassLoader::perf_resolve_method_type_time(),
1298 ClassLoader::perf_resolve_method_type_count());
1299
1300 Symbol* signature = this_cp->method_type_signature_at(cp_index);
1301 { ResourceMark rm(THREAD);
1302 log_debug(class, resolve)("resolve JVM_CONSTANT_MethodType [%d/%d] %s",
1303 cp_index, this_cp->method_type_index_at(cp_index),
1304 signature->as_C_string());
1305 }
1306 Klass* klass = this_cp->pool_holder();
1307 HandleMark hm(THREAD);
1308 Handle value = SystemDictionary::find_method_handle_type(signature, klass, THREAD);
1309 result_oop = value();
1310 if (HAS_PENDING_EXCEPTION) {
1311 save_and_throw_exception(this_cp, cp_index, tag, CHECK_NULL);
1312 }
1313 break;
1314 }
1315
1316 case JVM_CONSTANT_Integer:
1317 assert(cache_index == _no_index_sentinel, "should not have been set");
1318 prim_value.i = this_cp->int_at(cp_index);
1319 result_oop = java_lang_boxing_object::create(T_INT, &prim_value, CHECK_NULL);
1320 break;
1321
1322 case JVM_CONSTANT_Float:
1323 assert(cache_index == _no_index_sentinel, "should not have been set");
1324 prim_value.f = this_cp->float_at(cp_index);
1325 result_oop = java_lang_boxing_object::create(T_FLOAT, &prim_value, CHECK_NULL);
1326 break;
1327
1328 case JVM_CONSTANT_Long:
1329 assert(cache_index == _no_index_sentinel, "should not have been set");
1330 prim_value.j = this_cp->long_at(cp_index);
1331 result_oop = java_lang_boxing_object::create(T_LONG, &prim_value, CHECK_NULL);
1332 break;
1333
1334 case JVM_CONSTANT_Double:
1335 assert(cache_index == _no_index_sentinel, "should not have been set");
1336 prim_value.d = this_cp->double_at(cp_index);
1337 result_oop = java_lang_boxing_object::create(T_DOUBLE, &prim_value, CHECK_NULL);
1338 break;
1339
1340 case JVM_CONSTANT_UnresolvedClassInError:
1341 case JVM_CONSTANT_DynamicInError:
1342 case JVM_CONSTANT_MethodHandleInError:
1343 case JVM_CONSTANT_MethodTypeInError:
1344 throw_resolution_error(this_cp, cp_index, CHECK_NULL);
1345 break;
1346
1347 default:
1348 fatal("unexpected constant tag at CP %p[%d/%d] = %d", this_cp(), cp_index, cache_index, tag.value());
1349 break;
1350 }
1351
1352 if (cache_index >= 0) {
1353 // Benign race condition: resolved_references may already be filled in.
1354 // The important thing here is that all threads pick up the same result.
1355 // It doesn't matter which racing thread wins, as long as only one
1356 // result is used by all threads, and all future queries.
1357 oop new_result = (result_oop == nullptr ? Universe::the_null_sentinel() : result_oop);
1358 oop old_result = this_cp->set_resolved_reference_at(cache_index, new_result);
1359 if (old_result == nullptr) {
1360 return result_oop; // was installed
1361 } else {
1362 // Return the winning thread's result. This can be different than
1363 // the result here for MethodHandles.
1364 if (old_result == Universe::the_null_sentinel())
1365 old_result = nullptr;
1366 return old_result;
1367 }
1368 } else {
1369 assert(result_oop != Universe::the_null_sentinel(), "");
1370 return result_oop;
1371 }
1372 }
1373
1374 oop ConstantPool::uncached_string_at(int cp_index, TRAPS) {
1375 Symbol* sym = unresolved_string_at(cp_index);
1376 oop str = StringTable::intern(sym, CHECK_(nullptr));
1377 assert(java_lang_String::is_instance(str), "must be string");
1378 return str;
1379 }
1380
1381 void ConstantPool::copy_bootstrap_arguments_at_impl(const constantPoolHandle& this_cp, int cp_index,
1382 int start_arg, int end_arg,
1383 objArrayHandle info, int pos,
1384 bool must_resolve, Handle if_not_available,
1385 TRAPS) {
1386 int limit = pos + end_arg - start_arg;
1387 // checks: cp_index in range [0..this_cp->length),
1388 // tag at cp_index, start..end in range [0..this_cp->bootstrap_argument_count],
1389 // info array non-null, pos..limit in [0..info.length]
1390 if ((0 >= cp_index || cp_index >= this_cp->length()) ||
1391 !(this_cp->tag_at(cp_index).is_invoke_dynamic() ||
1392 this_cp->tag_at(cp_index).is_dynamic_constant()) ||
1393 (0 > start_arg || start_arg > end_arg) ||
1394 (end_arg > this_cp->bootstrap_argument_count_at(cp_index)) ||
1395 (0 > pos || pos > limit) ||
1396 (info.is_null() || limit > info->length())) {
1397 // An index or something else went wrong; throw an error.
1398 // Since this is an internal API, we don't expect this,
1399 // so we don't bother to craft a nice message.
1400 THROW_MSG(vmSymbols::java_lang_LinkageError(), "bad BSM argument access");
1401 }
1402 // now we can loop safely
1403 int info_i = pos;
1404 for (int i = start_arg; i < end_arg; i++) {
1405 int arg_index = this_cp->bootstrap_argument_index_at(cp_index, i);
1406 oop arg_oop;
1407 if (must_resolve) {
1408 arg_oop = this_cp->resolve_possibly_cached_constant_at(arg_index, CHECK);
1409 } else {
1410 bool found_it = false;
1411 arg_oop = this_cp->find_cached_constant_at(arg_index, found_it, CHECK);
1412 if (!found_it) arg_oop = if_not_available();
1413 }
1414 info->obj_at_put(info_i++, arg_oop);
1415 }
1416 }
1417
1418 oop ConstantPool::string_at_impl(const constantPoolHandle& this_cp, int cp_index, int obj_index, TRAPS) {
1419 // If the string has already been interned, this entry will be non-null
1420 oop str = this_cp->resolved_reference_at(obj_index);
1421 assert(str != Universe::the_null_sentinel(), "");
1422 if (str != nullptr) return str;
1423 Symbol* sym = this_cp->unresolved_string_at(cp_index);
1424 str = StringTable::intern(sym, CHECK_(nullptr));
1425 this_cp->string_at_put(obj_index, str);
1426 assert(java_lang_String::is_instance(str), "must be string");
1427 return str;
1428 }
1429
1430
1431 bool ConstantPool::klass_name_at_matches(const InstanceKlass* k, int cp_index) {
1432 // Names are interned, so we can compare Symbol*s directly
1433 Symbol* cp_name = klass_name_at(cp_index);
1434 return (cp_name == k->name());
1435 }
1436
1437
1438 // Iterate over symbols and decrement ones which are Symbol*s
1439 // This is done during GC.
1440 // Only decrement the UTF8 symbols. Strings point to
1441 // these symbols but didn't increment the reference count.
1442 void ConstantPool::unreference_symbols() {
1443 for (int index = 1; index < length(); index++) { // Index 0 is unused
1444 constantTag tag = tag_at(index);
1445 if (tag.is_symbol()) {
1446 symbol_at(index)->decrement_refcount();
1447 }
1448 }
1449 }
1450
1451
1452 // Compare this constant pool's entry at index1 to the constant pool
1453 // cp2's entry at index2.
1454 bool ConstantPool::compare_entry_to(int index1, const constantPoolHandle& cp2,
1455 int index2) {
1456
1457 // The error tags are equivalent to non-error tags when comparing
1458 jbyte t1 = tag_at(index1).non_error_value();
1459 jbyte t2 = cp2->tag_at(index2).non_error_value();
1460
1461 // Some classes are pre-resolved (like Throwable) which may lead to
1462 // consider it as a different entry. We then revert them back temporarily
1463 // to ensure proper comparison.
1464 if (t1 == JVM_CONSTANT_Class) {
1465 t1 = JVM_CONSTANT_UnresolvedClass;
1466 }
1467 if (t2 == JVM_CONSTANT_Class) {
1468 t2 = JVM_CONSTANT_UnresolvedClass;
1469 }
1470
1471 if (t1 != t2) {
1472 // Not the same entry type so there is nothing else to check. Note
1473 // that this style of checking will consider resolved/unresolved
1474 // class pairs as different.
1475 // From the ConstantPool* API point of view, this is correct
1476 // behavior. See VM_RedefineClasses::merge_constant_pools() to see how this
1477 // plays out in the context of ConstantPool* merging.
1478 return false;
1479 }
1480
1481 switch (t1) {
1482 case JVM_CONSTANT_ClassIndex:
1483 {
1484 int recur1 = klass_index_at(index1);
1485 int recur2 = cp2->klass_index_at(index2);
1486 if (compare_entry_to(recur1, cp2, recur2)) {
1487 return true;
1488 }
1489 } break;
1490
1491 case JVM_CONSTANT_Double:
1492 {
1493 jdouble d1 = double_at(index1);
1494 jdouble d2 = cp2->double_at(index2);
1495 if (d1 == d2) {
1496 return true;
1497 }
1498 } break;
1499
1500 case JVM_CONSTANT_Fieldref:
1501 case JVM_CONSTANT_InterfaceMethodref:
1502 case JVM_CONSTANT_Methodref:
1503 {
1504 int recur1 = uncached_klass_ref_index_at(index1);
1505 int recur2 = cp2->uncached_klass_ref_index_at(index2);
1506 bool match = compare_entry_to(recur1, cp2, recur2);
1507 if (match) {
1508 recur1 = uncached_name_and_type_ref_index_at(index1);
1509 recur2 = cp2->uncached_name_and_type_ref_index_at(index2);
1510 if (compare_entry_to(recur1, cp2, recur2)) {
1511 return true;
1512 }
1513 }
1514 } break;
1515
1516 case JVM_CONSTANT_Float:
1517 {
1518 jfloat f1 = float_at(index1);
1519 jfloat f2 = cp2->float_at(index2);
1520 if (f1 == f2) {
1521 return true;
1522 }
1523 } break;
1524
1525 case JVM_CONSTANT_Integer:
1526 {
1527 jint i1 = int_at(index1);
1528 jint i2 = cp2->int_at(index2);
1529 if (i1 == i2) {
1530 return true;
1531 }
1532 } break;
1533
1534 case JVM_CONSTANT_Long:
1535 {
1536 jlong l1 = long_at(index1);
1537 jlong l2 = cp2->long_at(index2);
1538 if (l1 == l2) {
1539 return true;
1540 }
1541 } break;
1542
1543 case JVM_CONSTANT_NameAndType:
1544 {
1545 int recur1 = name_ref_index_at(index1);
1546 int recur2 = cp2->name_ref_index_at(index2);
1547 if (compare_entry_to(recur1, cp2, recur2)) {
1548 recur1 = signature_ref_index_at(index1);
1549 recur2 = cp2->signature_ref_index_at(index2);
1550 if (compare_entry_to(recur1, cp2, recur2)) {
1551 return true;
1552 }
1553 }
1554 } break;
1555
1556 case JVM_CONSTANT_StringIndex:
1557 {
1558 int recur1 = string_index_at(index1);
1559 int recur2 = cp2->string_index_at(index2);
1560 if (compare_entry_to(recur1, cp2, recur2)) {
1561 return true;
1562 }
1563 } break;
1564
1565 case JVM_CONSTANT_UnresolvedClass:
1566 {
1567 Symbol* k1 = klass_name_at(index1);
1568 Symbol* k2 = cp2->klass_name_at(index2);
1569 if (k1 == k2) {
1570 return true;
1571 }
1572 } break;
1573
1574 case JVM_CONSTANT_MethodType:
1575 {
1576 int k1 = method_type_index_at(index1);
1577 int k2 = cp2->method_type_index_at(index2);
1578 if (compare_entry_to(k1, cp2, k2)) {
1579 return true;
1580 }
1581 } break;
1582
1583 case JVM_CONSTANT_MethodHandle:
1584 {
1585 int k1 = method_handle_ref_kind_at(index1);
1586 int k2 = cp2->method_handle_ref_kind_at(index2);
1587 if (k1 == k2) {
1588 int i1 = method_handle_index_at(index1);
1589 int i2 = cp2->method_handle_index_at(index2);
1590 if (compare_entry_to(i1, cp2, i2)) {
1591 return true;
1592 }
1593 }
1594 } break;
1595
1596 case JVM_CONSTANT_Dynamic:
1597 {
1598 int k1 = bootstrap_name_and_type_ref_index_at(index1);
1599 int k2 = cp2->bootstrap_name_and_type_ref_index_at(index2);
1600 int i1 = bootstrap_methods_attribute_index(index1);
1601 int i2 = cp2->bootstrap_methods_attribute_index(index2);
1602 bool match_entry = compare_entry_to(k1, cp2, k2);
1603 bool match_operand = compare_operand_to(i1, cp2, i2);
1604 return (match_entry && match_operand);
1605 } break;
1606
1607 case JVM_CONSTANT_InvokeDynamic:
1608 {
1609 int k1 = bootstrap_name_and_type_ref_index_at(index1);
1610 int k2 = cp2->bootstrap_name_and_type_ref_index_at(index2);
1611 int i1 = bootstrap_methods_attribute_index(index1);
1612 int i2 = cp2->bootstrap_methods_attribute_index(index2);
1613 bool match_entry = compare_entry_to(k1, cp2, k2);
1614 bool match_operand = compare_operand_to(i1, cp2, i2);
1615 return (match_entry && match_operand);
1616 } break;
1617
1618 case JVM_CONSTANT_String:
1619 {
1620 Symbol* s1 = unresolved_string_at(index1);
1621 Symbol* s2 = cp2->unresolved_string_at(index2);
1622 if (s1 == s2) {
1623 return true;
1624 }
1625 } break;
1626
1627 case JVM_CONSTANT_Utf8:
1628 {
1629 Symbol* s1 = symbol_at(index1);
1630 Symbol* s2 = cp2->symbol_at(index2);
1631 if (s1 == s2) {
1632 return true;
1633 }
1634 } break;
1635
1636 // Invalid is used as the tag for the second constant pool entry
1637 // occupied by JVM_CONSTANT_Double or JVM_CONSTANT_Long. It should
1638 // not be seen by itself.
1639 case JVM_CONSTANT_Invalid: // fall through
1640
1641 default:
1642 ShouldNotReachHere();
1643 break;
1644 }
1645
1646 return false;
1647 } // end compare_entry_to()
1648
1649
1650 // Resize the operands array with delta_len and delta_size.
1651 // Used in RedefineClasses for CP merge.
1652 void ConstantPool::resize_operands(int delta_len, int delta_size, TRAPS) {
1653 int old_len = operand_array_length(operands());
1654 int new_len = old_len + delta_len;
1655 int min_len = (delta_len > 0) ? old_len : new_len;
1656
1657 int old_size = operands()->length();
1658 int new_size = old_size + delta_size;
1659 int min_size = (delta_size > 0) ? old_size : new_size;
1660
1661 ClassLoaderData* loader_data = pool_holder()->class_loader_data();
1662 Array<u2>* new_ops = MetadataFactory::new_array<u2>(loader_data, new_size, CHECK);
1663
1664 // Set index in the resized array for existing elements only
1665 for (int idx = 0; idx < min_len; idx++) {
1666 int offset = operand_offset_at(idx); // offset in original array
1667 operand_offset_at_put(new_ops, idx, offset + 2*delta_len); // offset in resized array
1668 }
1669 // Copy the bootstrap specifiers only
1670 Copy::conjoint_memory_atomic(operands()->adr_at(2*old_len),
1671 new_ops->adr_at(2*new_len),
1672 (min_size - 2*min_len) * sizeof(u2));
1673 // Explicitly deallocate old operands array.
1674 // Note, it is not needed for 7u backport.
1675 if ( operands() != nullptr) { // the safety check
1676 MetadataFactory::free_array<u2>(loader_data, operands());
1677 }
1678 set_operands(new_ops);
1679 } // end resize_operands()
1680
1681
1682 // Extend the operands array with the length and size of the ext_cp operands.
1683 // Used in RedefineClasses for CP merge.
1684 void ConstantPool::extend_operands(const constantPoolHandle& ext_cp, TRAPS) {
1685 int delta_len = operand_array_length(ext_cp->operands());
1686 if (delta_len == 0) {
1687 return; // nothing to do
1688 }
1689 int delta_size = ext_cp->operands()->length();
1690
1691 assert(delta_len > 0 && delta_size > 0, "extended operands array must be bigger");
1692
1693 if (operand_array_length(operands()) == 0) {
1694 ClassLoaderData* loader_data = pool_holder()->class_loader_data();
1695 Array<u2>* new_ops = MetadataFactory::new_array<u2>(loader_data, delta_size, CHECK);
1696 // The first element index defines the offset of second part
1697 operand_offset_at_put(new_ops, 0, 2*delta_len); // offset in new array
1698 set_operands(new_ops);
1699 } else {
1700 resize_operands(delta_len, delta_size, CHECK);
1701 }
1702
1703 } // end extend_operands()
1704
1705
1706 // Shrink the operands array to a smaller array with new_len length.
1707 // Used in RedefineClasses for CP merge.
1708 void ConstantPool::shrink_operands(int new_len, TRAPS) {
1709 int old_len = operand_array_length(operands());
1710 if (new_len == old_len) {
1711 return; // nothing to do
1712 }
1713 assert(new_len < old_len, "shrunken operands array must be smaller");
1714
1715 int free_base = operand_next_offset_at(new_len - 1);
1716 int delta_len = new_len - old_len;
1717 int delta_size = 2*delta_len + free_base - operands()->length();
1718
1719 resize_operands(delta_len, delta_size, CHECK);
1720
1721 } // end shrink_operands()
1722
1723
1724 void ConstantPool::copy_operands(const constantPoolHandle& from_cp,
1725 const constantPoolHandle& to_cp,
1726 TRAPS) {
1727
1728 int from_oplen = operand_array_length(from_cp->operands());
1729 int old_oplen = operand_array_length(to_cp->operands());
1730 if (from_oplen != 0) {
1731 ClassLoaderData* loader_data = to_cp->pool_holder()->class_loader_data();
1732 // append my operands to the target's operands array
1733 if (old_oplen == 0) {
1734 // Can't just reuse from_cp's operand list because of deallocation issues
1735 int len = from_cp->operands()->length();
1736 Array<u2>* new_ops = MetadataFactory::new_array<u2>(loader_data, len, CHECK);
1737 Copy::conjoint_memory_atomic(
1738 from_cp->operands()->adr_at(0), new_ops->adr_at(0), len * sizeof(u2));
1739 to_cp->set_operands(new_ops);
1740 } else {
1741 int old_len = to_cp->operands()->length();
1742 int from_len = from_cp->operands()->length();
1743 int old_off = old_oplen * sizeof(u2);
1744 int from_off = from_oplen * sizeof(u2);
1745 // Use the metaspace for the destination constant pool
1746 Array<u2>* new_operands = MetadataFactory::new_array<u2>(loader_data, old_len + from_len, CHECK);
1747 int fillp = 0, len = 0;
1748 // first part of dest
1749 Copy::conjoint_memory_atomic(to_cp->operands()->adr_at(0),
1750 new_operands->adr_at(fillp),
1751 (len = old_off) * sizeof(u2));
1752 fillp += len;
1753 // first part of src
1754 Copy::conjoint_memory_atomic(from_cp->operands()->adr_at(0),
1755 new_operands->adr_at(fillp),
1756 (len = from_off) * sizeof(u2));
1757 fillp += len;
1758 // second part of dest
1759 Copy::conjoint_memory_atomic(to_cp->operands()->adr_at(old_off),
1760 new_operands->adr_at(fillp),
1761 (len = old_len - old_off) * sizeof(u2));
1762 fillp += len;
1763 // second part of src
1764 Copy::conjoint_memory_atomic(from_cp->operands()->adr_at(from_off),
1765 new_operands->adr_at(fillp),
1766 (len = from_len - from_off) * sizeof(u2));
1767 fillp += len;
1768 assert(fillp == new_operands->length(), "");
1769
1770 // Adjust indexes in the first part of the copied operands array.
1771 for (int j = 0; j < from_oplen; j++) {
1772 int offset = operand_offset_at(new_operands, old_oplen + j);
1773 assert(offset == operand_offset_at(from_cp->operands(), j), "correct copy");
1774 offset += old_len; // every new tuple is preceded by old_len extra u2's
1775 operand_offset_at_put(new_operands, old_oplen + j, offset);
1776 }
1777
1778 // replace target operands array with combined array
1779 to_cp->set_operands(new_operands);
1780 }
1781 }
1782 } // end copy_operands()
1783
1784
1785 // Copy this constant pool's entries at start_i to end_i (inclusive)
1786 // to the constant pool to_cp's entries starting at to_i. A total of
1787 // (end_i - start_i) + 1 entries are copied.
1788 void ConstantPool::copy_cp_to_impl(const constantPoolHandle& from_cp, int start_i, int end_i,
1789 const constantPoolHandle& to_cp, int to_i, TRAPS) {
1790
1791
1792 int dest_cpi = to_i; // leave original alone for debug purposes
1793
1794 for (int src_cpi = start_i; src_cpi <= end_i; /* see loop bottom */ ) {
1795 copy_entry_to(from_cp, src_cpi, to_cp, dest_cpi);
1796
1797 switch (from_cp->tag_at(src_cpi).value()) {
1798 case JVM_CONSTANT_Double:
1799 case JVM_CONSTANT_Long:
1800 // double and long take two constant pool entries
1801 src_cpi += 2;
1802 dest_cpi += 2;
1803 break;
1804
1805 default:
1806 // all others take one constant pool entry
1807 src_cpi++;
1808 dest_cpi++;
1809 break;
1810 }
1811 }
1812 copy_operands(from_cp, to_cp, CHECK);
1813
1814 } // end copy_cp_to_impl()
1815
1816
1817 // Copy this constant pool's entry at from_i to the constant pool
1818 // to_cp's entry at to_i.
1819 void ConstantPool::copy_entry_to(const constantPoolHandle& from_cp, int from_i,
1820 const constantPoolHandle& to_cp, int to_i) {
1821
1822 int tag = from_cp->tag_at(from_i).value();
1823 switch (tag) {
1824 case JVM_CONSTANT_ClassIndex:
1825 {
1826 jint ki = from_cp->klass_index_at(from_i);
1827 to_cp->klass_index_at_put(to_i, ki);
1828 } break;
1829
1830 case JVM_CONSTANT_Double:
1831 {
1832 jdouble d = from_cp->double_at(from_i);
1833 to_cp->double_at_put(to_i, d);
1834 // double takes two constant pool entries so init second entry's tag
1835 to_cp->tag_at_put(to_i + 1, JVM_CONSTANT_Invalid);
1836 } break;
1837
1838 case JVM_CONSTANT_Fieldref:
1839 {
1840 int class_index = from_cp->uncached_klass_ref_index_at(from_i);
1841 int name_and_type_index = from_cp->uncached_name_and_type_ref_index_at(from_i);
1842 to_cp->field_at_put(to_i, class_index, name_and_type_index);
1843 } break;
1844
1845 case JVM_CONSTANT_Float:
1846 {
1847 jfloat f = from_cp->float_at(from_i);
1848 to_cp->float_at_put(to_i, f);
1849 } break;
1850
1851 case JVM_CONSTANT_Integer:
1852 {
1853 jint i = from_cp->int_at(from_i);
1854 to_cp->int_at_put(to_i, i);
1855 } break;
1856
1857 case JVM_CONSTANT_InterfaceMethodref:
1858 {
1859 int class_index = from_cp->uncached_klass_ref_index_at(from_i);
1860 int name_and_type_index = from_cp->uncached_name_and_type_ref_index_at(from_i);
1861 to_cp->interface_method_at_put(to_i, class_index, name_and_type_index);
1862 } break;
1863
1864 case JVM_CONSTANT_Long:
1865 {
1866 jlong l = from_cp->long_at(from_i);
1867 to_cp->long_at_put(to_i, l);
1868 // long takes two constant pool entries so init second entry's tag
1869 to_cp->tag_at_put(to_i + 1, JVM_CONSTANT_Invalid);
1870 } break;
1871
1872 case JVM_CONSTANT_Methodref:
1873 {
1874 int class_index = from_cp->uncached_klass_ref_index_at(from_i);
1875 int name_and_type_index = from_cp->uncached_name_and_type_ref_index_at(from_i);
1876 to_cp->method_at_put(to_i, class_index, name_and_type_index);
1877 } break;
1878
1879 case JVM_CONSTANT_NameAndType:
1880 {
1881 int name_ref_index = from_cp->name_ref_index_at(from_i);
1882 int signature_ref_index = from_cp->signature_ref_index_at(from_i);
1883 to_cp->name_and_type_at_put(to_i, name_ref_index, signature_ref_index);
1884 } break;
1885
1886 case JVM_CONSTANT_StringIndex:
1887 {
1888 jint si = from_cp->string_index_at(from_i);
1889 to_cp->string_index_at_put(to_i, si);
1890 } break;
1891
1892 case JVM_CONSTANT_Class:
1893 case JVM_CONSTANT_UnresolvedClass:
1894 case JVM_CONSTANT_UnresolvedClassInError:
1895 {
1896 // Revert to JVM_CONSTANT_ClassIndex
1897 int name_index = from_cp->klass_slot_at(from_i).name_index();
1898 assert(from_cp->tag_at(name_index).is_symbol(), "sanity");
1899 to_cp->klass_index_at_put(to_i, name_index);
1900 } break;
1901
1902 case JVM_CONSTANT_String:
1903 {
1904 Symbol* s = from_cp->unresolved_string_at(from_i);
1905 to_cp->unresolved_string_at_put(to_i, s);
1906 } break;
1907
1908 case JVM_CONSTANT_Utf8:
1909 {
1910 Symbol* s = from_cp->symbol_at(from_i);
1911 // Need to increase refcount, the old one will be thrown away and deferenced
1912 s->increment_refcount();
1913 to_cp->symbol_at_put(to_i, s);
1914 } break;
1915
1916 case JVM_CONSTANT_MethodType:
1917 case JVM_CONSTANT_MethodTypeInError:
1918 {
1919 jint k = from_cp->method_type_index_at(from_i);
1920 to_cp->method_type_index_at_put(to_i, k);
1921 } break;
1922
1923 case JVM_CONSTANT_MethodHandle:
1924 case JVM_CONSTANT_MethodHandleInError:
1925 {
1926 int k1 = from_cp->method_handle_ref_kind_at(from_i);
1927 int k2 = from_cp->method_handle_index_at(from_i);
1928 to_cp->method_handle_index_at_put(to_i, k1, k2);
1929 } break;
1930
1931 case JVM_CONSTANT_Dynamic:
1932 case JVM_CONSTANT_DynamicInError:
1933 {
1934 int k1 = from_cp->bootstrap_methods_attribute_index(from_i);
1935 int k2 = from_cp->bootstrap_name_and_type_ref_index_at(from_i);
1936 k1 += operand_array_length(to_cp->operands()); // to_cp might already have operands
1937 to_cp->dynamic_constant_at_put(to_i, k1, k2);
1938 } break;
1939
1940 case JVM_CONSTANT_InvokeDynamic:
1941 {
1942 int k1 = from_cp->bootstrap_methods_attribute_index(from_i);
1943 int k2 = from_cp->bootstrap_name_and_type_ref_index_at(from_i);
1944 k1 += operand_array_length(to_cp->operands()); // to_cp might already have operands
1945 to_cp->invoke_dynamic_at_put(to_i, k1, k2);
1946 } break;
1947
1948 // Invalid is used as the tag for the second constant pool entry
1949 // occupied by JVM_CONSTANT_Double or JVM_CONSTANT_Long. It should
1950 // not be seen by itself.
1951 case JVM_CONSTANT_Invalid: // fall through
1952
1953 default:
1954 {
1955 ShouldNotReachHere();
1956 } break;
1957 }
1958 } // end copy_entry_to()
1959
1960 // Search constant pool search_cp for an entry that matches this
1961 // constant pool's entry at pattern_i. Returns the index of a
1962 // matching entry or zero (0) if there is no matching entry.
1963 int ConstantPool::find_matching_entry(int pattern_i,
1964 const constantPoolHandle& search_cp) {
1965
1966 // index zero (0) is not used
1967 for (int i = 1; i < search_cp->length(); i++) {
1968 bool found = compare_entry_to(pattern_i, search_cp, i);
1969 if (found) {
1970 return i;
1971 }
1972 }
1973
1974 return 0; // entry not found; return unused index zero (0)
1975 } // end find_matching_entry()
1976
1977
1978 // Compare this constant pool's bootstrap specifier at idx1 to the constant pool
1979 // cp2's bootstrap specifier at idx2.
1980 bool ConstantPool::compare_operand_to(int idx1, const constantPoolHandle& cp2, int idx2) {
1981 int k1 = operand_bootstrap_method_ref_index_at(idx1);
1982 int k2 = cp2->operand_bootstrap_method_ref_index_at(idx2);
1983 bool match = compare_entry_to(k1, cp2, k2);
1984
1985 if (!match) {
1986 return false;
1987 }
1988 int argc = operand_argument_count_at(idx1);
1989 if (argc == cp2->operand_argument_count_at(idx2)) {
1990 for (int j = 0; j < argc; j++) {
1991 k1 = operand_argument_index_at(idx1, j);
1992 k2 = cp2->operand_argument_index_at(idx2, j);
1993 match = compare_entry_to(k1, cp2, k2);
1994 if (!match) {
1995 return false;
1996 }
1997 }
1998 return true; // got through loop; all elements equal
1999 }
2000 return false;
2001 } // end compare_operand_to()
2002
2003 // Search constant pool search_cp for a bootstrap specifier that matches
2004 // this constant pool's bootstrap specifier data at pattern_i index.
2005 // Return the index of a matching bootstrap attribute record or (-1) if there is no match.
2006 int ConstantPool::find_matching_operand(int pattern_i,
2007 const constantPoolHandle& search_cp, int search_len) {
2008 for (int i = 0; i < search_len; i++) {
2009 bool found = compare_operand_to(pattern_i, search_cp, i);
2010 if (found) {
2011 return i;
2012 }
2013 }
2014 return -1; // bootstrap specifier data not found; return unused index (-1)
2015 } // end find_matching_operand()
2016
2017
2018 #ifndef PRODUCT
2019
2020 const char* ConstantPool::printable_name_at(int cp_index) {
2021
2022 constantTag tag = tag_at(cp_index);
2023
2024 if (tag.is_string()) {
2025 return string_at_noresolve(cp_index);
2026 } else if (tag.is_klass() || tag.is_unresolved_klass()) {
2027 return klass_name_at(cp_index)->as_C_string();
2028 } else if (tag.is_symbol()) {
2029 return symbol_at(cp_index)->as_C_string();
2030 }
2031 return "";
2032 }
2033
2034 #endif // PRODUCT
2035
2036
2037 // JVMTI GetConstantPool support
2038
2039 // For debugging of constant pool
2040 const bool debug_cpool = false;
2041
2042 #define DBG(code) do { if (debug_cpool) { (code); } } while(0)
2043
2044 static void print_cpool_bytes(jint cnt, u1 *bytes) {
2045 const char* WARN_MSG = "Must not be such entry!";
2046 jint size = 0;
2047 u2 idx1, idx2;
2048
2049 for (jint idx = 1; idx < cnt; idx++) {
2050 jint ent_size = 0;
2051 u1 tag = *bytes++;
2052 size++; // count tag
2053
2054 printf("const #%03d, tag: %02d ", idx, tag);
2055 switch(tag) {
2056 case JVM_CONSTANT_Invalid: {
2057 printf("Invalid");
2058 break;
2059 }
2060 case JVM_CONSTANT_Unicode: {
2061 printf("Unicode %s", WARN_MSG);
2062 break;
2063 }
2064 case JVM_CONSTANT_Utf8: {
2065 u2 len = Bytes::get_Java_u2(bytes);
2066 char str[128];
2067 if (len > 127) {
2068 len = 127;
2069 }
2070 strncpy(str, (char *) (bytes+2), len);
2071 str[len] = '\0';
2072 printf("Utf8 \"%s\"", str);
2073 ent_size = 2 + len;
2074 break;
2075 }
2076 case JVM_CONSTANT_Integer: {
2077 u4 val = Bytes::get_Java_u4(bytes);
2078 printf("int %d", *(int *) &val);
2079 ent_size = 4;
2080 break;
2081 }
2082 case JVM_CONSTANT_Float: {
2083 u4 val = Bytes::get_Java_u4(bytes);
2084 printf("float %5.3ff", *(float *) &val);
2085 ent_size = 4;
2086 break;
2087 }
2088 case JVM_CONSTANT_Long: {
2089 u8 val = Bytes::get_Java_u8(bytes);
2090 printf("long " INT64_FORMAT, (int64_t) *(jlong *) &val);
2091 ent_size = 8;
2092 idx++; // Long takes two cpool slots
2093 break;
2094 }
2095 case JVM_CONSTANT_Double: {
2096 u8 val = Bytes::get_Java_u8(bytes);
2097 printf("double %5.3fd", *(jdouble *)&val);
2098 ent_size = 8;
2099 idx++; // Double takes two cpool slots
2100 break;
2101 }
2102 case JVM_CONSTANT_Class: {
2103 idx1 = Bytes::get_Java_u2(bytes);
2104 printf("class #%03d", idx1);
2105 ent_size = 2;
2106 break;
2107 }
2108 case JVM_CONSTANT_String: {
2109 idx1 = Bytes::get_Java_u2(bytes);
2110 printf("String #%03d", idx1);
2111 ent_size = 2;
2112 break;
2113 }
2114 case JVM_CONSTANT_Fieldref: {
2115 idx1 = Bytes::get_Java_u2(bytes);
2116 idx2 = Bytes::get_Java_u2(bytes+2);
2117 printf("Field #%03d, #%03d", (int) idx1, (int) idx2);
2118 ent_size = 4;
2119 break;
2120 }
2121 case JVM_CONSTANT_Methodref: {
2122 idx1 = Bytes::get_Java_u2(bytes);
2123 idx2 = Bytes::get_Java_u2(bytes+2);
2124 printf("Method #%03d, #%03d", idx1, idx2);
2125 ent_size = 4;
2126 break;
2127 }
2128 case JVM_CONSTANT_InterfaceMethodref: {
2129 idx1 = Bytes::get_Java_u2(bytes);
2130 idx2 = Bytes::get_Java_u2(bytes+2);
2131 printf("InterfMethod #%03d, #%03d", idx1, idx2);
2132 ent_size = 4;
2133 break;
2134 }
2135 case JVM_CONSTANT_NameAndType: {
2136 idx1 = Bytes::get_Java_u2(bytes);
2137 idx2 = Bytes::get_Java_u2(bytes+2);
2138 printf("NameAndType #%03d, #%03d", idx1, idx2);
2139 ent_size = 4;
2140 break;
2141 }
2142 case JVM_CONSTANT_ClassIndex: {
2143 printf("ClassIndex %s", WARN_MSG);
2144 break;
2145 }
2146 case JVM_CONSTANT_UnresolvedClass: {
2147 printf("UnresolvedClass: %s", WARN_MSG);
2148 break;
2149 }
2150 case JVM_CONSTANT_UnresolvedClassInError: {
2151 printf("UnresolvedClassInErr: %s", WARN_MSG);
2152 break;
2153 }
2154 case JVM_CONSTANT_StringIndex: {
2155 printf("StringIndex: %s", WARN_MSG);
2156 break;
2157 }
2158 }
2159 printf(";\n");
2160 bytes += ent_size;
2161 size += ent_size;
2162 }
2163 printf("Cpool size: %d\n", size);
2164 fflush(nullptr);
2165 return;
2166 } /* end print_cpool_bytes */
2167
2168
2169 // Returns size of constant pool entry.
2170 jint ConstantPool::cpool_entry_size(jint idx) {
2171 switch(tag_at(idx).value()) {
2172 case JVM_CONSTANT_Invalid:
2173 case JVM_CONSTANT_Unicode:
2174 return 1;
2175
2176 case JVM_CONSTANT_Utf8:
2177 return 3 + symbol_at(idx)->utf8_length();
2178
2179 case JVM_CONSTANT_Class:
2180 case JVM_CONSTANT_String:
2181 case JVM_CONSTANT_ClassIndex:
2182 case JVM_CONSTANT_UnresolvedClass:
2183 case JVM_CONSTANT_UnresolvedClassInError:
2184 case JVM_CONSTANT_StringIndex:
2185 case JVM_CONSTANT_MethodType:
2186 case JVM_CONSTANT_MethodTypeInError:
2187 return 3;
2188
2189 case JVM_CONSTANT_MethodHandle:
2190 case JVM_CONSTANT_MethodHandleInError:
2191 return 4; //tag, ref_kind, ref_index
2192
2193 case JVM_CONSTANT_Integer:
2194 case JVM_CONSTANT_Float:
2195 case JVM_CONSTANT_Fieldref:
2196 case JVM_CONSTANT_Methodref:
2197 case JVM_CONSTANT_InterfaceMethodref:
2198 case JVM_CONSTANT_NameAndType:
2199 return 5;
2200
2201 case JVM_CONSTANT_Dynamic:
2202 case JVM_CONSTANT_DynamicInError:
2203 case JVM_CONSTANT_InvokeDynamic:
2204 // u1 tag, u2 bsm, u2 nt
2205 return 5;
2206
2207 case JVM_CONSTANT_Long:
2208 case JVM_CONSTANT_Double:
2209 return 9;
2210 }
2211 assert(false, "cpool_entry_size: Invalid constant pool entry tag");
2212 return 1;
2213 } /* end cpool_entry_size */
2214
2215
2216 // SymbolHash is used to find a constant pool index from a string.
2217 // This function fills in SymbolHashs, one for utf8s and one for
2218 // class names, returns size of the cpool raw bytes.
2219 jint ConstantPool::hash_entries_to(SymbolHash *symmap,
2220 SymbolHash *classmap) {
2221 jint size = 0;
2222
2223 for (u2 idx = 1; idx < length(); idx++) {
2224 u2 tag = tag_at(idx).value();
2225 size += cpool_entry_size(idx);
2226
2227 switch(tag) {
2228 case JVM_CONSTANT_Utf8: {
2229 Symbol* sym = symbol_at(idx);
2230 symmap->add_if_absent(sym, idx);
2231 DBG(printf("adding symbol entry %s = %d\n", sym->as_utf8(), idx));
2232 break;
2233 }
2234 case JVM_CONSTANT_Class:
2235 case JVM_CONSTANT_UnresolvedClass:
2236 case JVM_CONSTANT_UnresolvedClassInError: {
2237 Symbol* sym = klass_name_at(idx);
2238 classmap->add_if_absent(sym, idx);
2239 DBG(printf("adding class entry %s = %d\n", sym->as_utf8(), idx));
2240 break;
2241 }
2242 case JVM_CONSTANT_Long:
2243 case JVM_CONSTANT_Double: {
2244 idx++; // Both Long and Double take two cpool slots
2245 break;
2246 }
2247 }
2248 }
2249 return size;
2250 } /* end hash_utf8_entries_to */
2251
2252
2253 // Copy cpool bytes.
2254 // Returns:
2255 // 0, in case of OutOfMemoryError
2256 // -1, in case of internal error
2257 // > 0, count of the raw cpool bytes that have been copied
2258 int ConstantPool::copy_cpool_bytes(int cpool_size,
2259 SymbolHash* tbl,
2260 unsigned char *bytes) {
2261 u2 idx1, idx2;
2262 jint size = 0;
2263 jint cnt = length();
2264 unsigned char *start_bytes = bytes;
2265
2266 for (jint idx = 1; idx < cnt; idx++) {
2267 u1 tag = tag_at(idx).value();
2268 jint ent_size = cpool_entry_size(idx);
2269
2270 assert(size + ent_size <= cpool_size, "Size mismatch");
2271
2272 *bytes = tag;
2273 DBG(printf("#%03hd tag=%03hd, ", (short)idx, (short)tag));
2274 switch(tag) {
2275 case JVM_CONSTANT_Invalid: {
2276 DBG(printf("JVM_CONSTANT_Invalid"));
2277 break;
2278 }
2279 case JVM_CONSTANT_Unicode: {
2280 assert(false, "Wrong constant pool tag: JVM_CONSTANT_Unicode");
2281 DBG(printf("JVM_CONSTANT_Unicode"));
2282 break;
2283 }
2284 case JVM_CONSTANT_Utf8: {
2285 Symbol* sym = symbol_at(idx);
2286 char* str = sym->as_utf8();
2287 // Warning! It's crashing on x86 with len = sym->utf8_length()
2288 int len = (int) strlen(str);
2289 Bytes::put_Java_u2((address) (bytes+1), (u2) len);
2290 for (int i = 0; i < len; i++) {
2291 bytes[3+i] = (u1) str[i];
2292 }
2293 DBG(printf("JVM_CONSTANT_Utf8: %s ", str));
2294 break;
2295 }
2296 case JVM_CONSTANT_Integer: {
2297 jint val = int_at(idx);
2298 Bytes::put_Java_u4((address) (bytes+1), *(u4*)&val);
2299 break;
2300 }
2301 case JVM_CONSTANT_Float: {
2302 jfloat val = float_at(idx);
2303 Bytes::put_Java_u4((address) (bytes+1), *(u4*)&val);
2304 break;
2305 }
2306 case JVM_CONSTANT_Long: {
2307 jlong val = long_at(idx);
2308 Bytes::put_Java_u8((address) (bytes+1), *(u8*)&val);
2309 idx++; // Long takes two cpool slots
2310 break;
2311 }
2312 case JVM_CONSTANT_Double: {
2313 jdouble val = double_at(idx);
2314 Bytes::put_Java_u8((address) (bytes+1), *(u8*)&val);
2315 idx++; // Double takes two cpool slots
2316 break;
2317 }
2318 case JVM_CONSTANT_Class:
2319 case JVM_CONSTANT_UnresolvedClass:
2320 case JVM_CONSTANT_UnresolvedClassInError: {
2321 *bytes = JVM_CONSTANT_Class;
2322 Symbol* sym = klass_name_at(idx);
2323 idx1 = tbl->symbol_to_value(sym);
2324 assert(idx1 != 0, "Have not found a hashtable entry");
2325 Bytes::put_Java_u2((address) (bytes+1), idx1);
2326 DBG(printf("JVM_CONSTANT_Class: idx=#%03hd, %s", idx1, sym->as_utf8()));
2327 break;
2328 }
2329 case JVM_CONSTANT_String: {
2330 *bytes = JVM_CONSTANT_String;
2331 Symbol* sym = unresolved_string_at(idx);
2332 idx1 = tbl->symbol_to_value(sym);
2333 assert(idx1 != 0, "Have not found a hashtable entry");
2334 Bytes::put_Java_u2((address) (bytes+1), idx1);
2335 DBG(printf("JVM_CONSTANT_String: idx=#%03hd, %s", idx1, sym->as_utf8()));
2336 break;
2337 }
2338 case JVM_CONSTANT_Fieldref:
2339 case JVM_CONSTANT_Methodref:
2340 case JVM_CONSTANT_InterfaceMethodref: {
2341 idx1 = uncached_klass_ref_index_at(idx);
2342 idx2 = uncached_name_and_type_ref_index_at(idx);
2343 Bytes::put_Java_u2((address) (bytes+1), idx1);
2344 Bytes::put_Java_u2((address) (bytes+3), idx2);
2345 DBG(printf("JVM_CONSTANT_Methodref: %hd %hd", idx1, idx2));
2346 break;
2347 }
2348 case JVM_CONSTANT_NameAndType: {
2349 idx1 = name_ref_index_at(idx);
2350 idx2 = signature_ref_index_at(idx);
2351 Bytes::put_Java_u2((address) (bytes+1), idx1);
2352 Bytes::put_Java_u2((address) (bytes+3), idx2);
2353 DBG(printf("JVM_CONSTANT_NameAndType: %hd %hd", idx1, idx2));
2354 break;
2355 }
2356 case JVM_CONSTANT_ClassIndex: {
2357 *bytes = JVM_CONSTANT_Class;
2358 idx1 = checked_cast<u2>(klass_index_at(idx));
2359 Bytes::put_Java_u2((address) (bytes+1), idx1);
2360 DBG(printf("JVM_CONSTANT_ClassIndex: %hd", idx1));
2361 break;
2362 }
2363 case JVM_CONSTANT_StringIndex: {
2364 *bytes = JVM_CONSTANT_String;
2365 idx1 = checked_cast<u2>(string_index_at(idx));
2366 Bytes::put_Java_u2((address) (bytes+1), idx1);
2367 DBG(printf("JVM_CONSTANT_StringIndex: %hd", idx1));
2368 break;
2369 }
2370 case JVM_CONSTANT_MethodHandle:
2371 case JVM_CONSTANT_MethodHandleInError: {
2372 *bytes = JVM_CONSTANT_MethodHandle;
2373 int kind = method_handle_ref_kind_at(idx);
2374 idx1 = checked_cast<u2>(method_handle_index_at(idx));
2375 *(bytes+1) = (unsigned char) kind;
2376 Bytes::put_Java_u2((address) (bytes+2), idx1);
2377 DBG(printf("JVM_CONSTANT_MethodHandle: %d %hd", kind, idx1));
2378 break;
2379 }
2380 case JVM_CONSTANT_MethodType:
2381 case JVM_CONSTANT_MethodTypeInError: {
2382 *bytes = JVM_CONSTANT_MethodType;
2383 idx1 = checked_cast<u2>(method_type_index_at(idx));
2384 Bytes::put_Java_u2((address) (bytes+1), idx1);
2385 DBG(printf("JVM_CONSTANT_MethodType: %hd", idx1));
2386 break;
2387 }
2388 case JVM_CONSTANT_Dynamic:
2389 case JVM_CONSTANT_DynamicInError: {
2390 *bytes = tag;
2391 idx1 = extract_low_short_from_int(*int_at_addr(idx));
2392 idx2 = extract_high_short_from_int(*int_at_addr(idx));
2393 assert(idx2 == bootstrap_name_and_type_ref_index_at(idx), "correct half of u4");
2394 Bytes::put_Java_u2((address) (bytes+1), idx1);
2395 Bytes::put_Java_u2((address) (bytes+3), idx2);
2396 DBG(printf("JVM_CONSTANT_Dynamic: %hd %hd", idx1, idx2));
2397 break;
2398 }
2399 case JVM_CONSTANT_InvokeDynamic: {
2400 *bytes = tag;
2401 idx1 = extract_low_short_from_int(*int_at_addr(idx));
2402 idx2 = extract_high_short_from_int(*int_at_addr(idx));
2403 assert(idx2 == bootstrap_name_and_type_ref_index_at(idx), "correct half of u4");
2404 Bytes::put_Java_u2((address) (bytes+1), idx1);
2405 Bytes::put_Java_u2((address) (bytes+3), idx2);
2406 DBG(printf("JVM_CONSTANT_InvokeDynamic: %hd %hd", idx1, idx2));
2407 break;
2408 }
2409 }
2410 DBG(printf("\n"));
2411 bytes += ent_size;
2412 size += ent_size;
2413 }
2414 assert(size == cpool_size, "Size mismatch");
2415
2416 // Keep temporarily for debugging until it's stable.
2417 DBG(print_cpool_bytes(cnt, start_bytes));
2418 return (int)(bytes - start_bytes);
2419 } /* end copy_cpool_bytes */
2420
2421 #undef DBG
2422
2423 bool ConstantPool::is_maybe_on_stack() const {
2424 // This method uses the similar logic as nmethod::is_maybe_on_stack()
2425 if (!Continuations::enabled()) {
2426 return false;
2427 }
2428
2429 // If the condition below is true, it means that the nmethod was found to
2430 // be alive the previous completed marking cycle.
2431 return cache()->gc_epoch() >= CodeCache::previous_completed_gc_marking_cycle();
2432 }
2433
2434 // For redefinition, if any methods found in loom stack chunks, the gc_epoch is
2435 // recorded in their constant pool cache. The on_stack-ness of the constant pool controls whether
2436 // memory for the method is reclaimed.
2437 bool ConstantPool::on_stack() const {
2438 if ((_flags &_on_stack) != 0) {
2439 return true;
2440 }
2441
2442 if (_cache == nullptr) {
2443 return false;
2444 }
2445
2446 return is_maybe_on_stack();
2447 }
2448
2449 void ConstantPool::set_on_stack(const bool value) {
2450 if (value) {
2451 // Only record if it's not already set.
2452 if (!on_stack()) {
2453 assert(!is_shared(), "should always be set for shared constant pools");
2454 _flags |= _on_stack;
2455 MetadataOnStackMark::record(this);
2456 }
2457 } else {
2458 // Clearing is done single-threadedly.
2459 if (!is_shared()) {
2460 _flags &= (u2)(~_on_stack);
2461 }
2462 }
2463 }
2464
2465 // Printing
2466
2467 void ConstantPool::print_on(outputStream* st) const {
2468 assert(is_constantPool(), "must be constantPool");
2469 st->print_cr("%s", internal_name());
2470 if (flags() != 0) {
2471 st->print(" - flags: 0x%x", flags());
2472 if (has_preresolution()) st->print(" has_preresolution");
2473 if (on_stack()) st->print(" on_stack");
2474 st->cr();
2475 }
2476 if (pool_holder() != nullptr) {
2477 st->print_cr(" - holder: " PTR_FORMAT, p2i(pool_holder()));
2478 }
2479 st->print_cr(" - cache: " PTR_FORMAT, p2i(cache()));
2480 st->print_cr(" - resolved_references: " PTR_FORMAT, p2i(resolved_references_or_null()));
2481 st->print_cr(" - reference_map: " PTR_FORMAT, p2i(reference_map()));
2482 st->print_cr(" - resolved_klasses: " PTR_FORMAT, p2i(resolved_klasses()));
2483 st->print_cr(" - cp length: %d", length());
2484
2485 for (int index = 1; index < length(); index++) { // Index 0 is unused
2486 ((ConstantPool*)this)->print_entry_on(index, st);
2487 switch (tag_at(index).value()) {
2488 case JVM_CONSTANT_Long :
2489 case JVM_CONSTANT_Double :
2490 index++; // Skip entry following eigth-byte constant
2491 }
2492
2493 }
2494 st->cr();
2495 }
2496
2497 // Print one constant pool entry
2498 void ConstantPool::print_entry_on(const int cp_index, outputStream* st) {
2499 EXCEPTION_MARK;
2500 st->print(" - %3d : ", cp_index);
2501 tag_at(cp_index).print_on(st);
2502 st->print(" : ");
2503 switch (tag_at(cp_index).value()) {
2504 case JVM_CONSTANT_Class :
2505 { Klass* k = klass_at(cp_index, CATCH);
2506 guarantee(k != nullptr, "need klass");
2507 k->print_value_on(st);
2508 st->print(" {" PTR_FORMAT "}", p2i(k));
2509 }
2510 break;
2511 case JVM_CONSTANT_Fieldref :
2512 case JVM_CONSTANT_Methodref :
2513 case JVM_CONSTANT_InterfaceMethodref :
2514 st->print("klass_index=%d", uncached_klass_ref_index_at(cp_index));
2515 st->print(" name_and_type_index=%d", uncached_name_and_type_ref_index_at(cp_index));
2516 break;
2517 case JVM_CONSTANT_String :
2518 unresolved_string_at(cp_index)->print_value_on(st);
2519 break;
2520 case JVM_CONSTANT_Integer :
2521 st->print("%d", int_at(cp_index));
2522 break;
2523 case JVM_CONSTANT_Float :
2524 st->print("%f", float_at(cp_index));
2525 break;
2526 case JVM_CONSTANT_Long :
2527 st->print_jlong(long_at(cp_index));
2528 break;
2529 case JVM_CONSTANT_Double :
2530 st->print("%lf", double_at(cp_index));
2531 break;
2532 case JVM_CONSTANT_NameAndType :
2533 st->print("name_index=%d", name_ref_index_at(cp_index));
2534 st->print(" signature_index=%d", signature_ref_index_at(cp_index));
2535 break;
2536 case JVM_CONSTANT_Utf8 :
2537 symbol_at(cp_index)->print_value_on(st);
2538 break;
2539 case JVM_CONSTANT_ClassIndex: {
2540 int name_index = *int_at_addr(cp_index);
2541 st->print("klass_index=%d ", name_index);
2542 symbol_at(name_index)->print_value_on(st);
2543 }
2544 break;
2545 case JVM_CONSTANT_UnresolvedClass : // fall-through
2546 case JVM_CONSTANT_UnresolvedClassInError: {
2547 CPKlassSlot kslot = klass_slot_at(cp_index);
2548 int resolved_klass_index = kslot.resolved_klass_index();
2549 int name_index = kslot.name_index();
2550 assert(tag_at(name_index).is_symbol(), "sanity");
2551 symbol_at(name_index)->print_value_on(st);
2552 }
2553 break;
2554 case JVM_CONSTANT_MethodHandle :
2555 case JVM_CONSTANT_MethodHandleInError :
2556 st->print("ref_kind=%d", method_handle_ref_kind_at(cp_index));
2557 st->print(" ref_index=%d", method_handle_index_at(cp_index));
2558 break;
2559 case JVM_CONSTANT_MethodType :
2560 case JVM_CONSTANT_MethodTypeInError :
2561 st->print("signature_index=%d", method_type_index_at(cp_index));
2562 break;
2563 case JVM_CONSTANT_Dynamic :
2564 case JVM_CONSTANT_DynamicInError :
2565 {
2566 st->print("bootstrap_method_index=%d", bootstrap_method_ref_index_at(cp_index));
2567 st->print(" type_index=%d", bootstrap_name_and_type_ref_index_at(cp_index));
2568 int argc = bootstrap_argument_count_at(cp_index);
2569 if (argc > 0) {
2570 for (int arg_i = 0; arg_i < argc; arg_i++) {
2571 int arg = bootstrap_argument_index_at(cp_index, arg_i);
2572 st->print((arg_i == 0 ? " arguments={%d" : ", %d"), arg);
2573 }
2574 st->print("}");
2575 }
2576 }
2577 break;
2578 case JVM_CONSTANT_InvokeDynamic :
2579 {
2580 st->print("bootstrap_method_index=%d", bootstrap_method_ref_index_at(cp_index));
2581 st->print(" name_and_type_index=%d", bootstrap_name_and_type_ref_index_at(cp_index));
2582 int argc = bootstrap_argument_count_at(cp_index);
2583 if (argc > 0) {
2584 for (int arg_i = 0; arg_i < argc; arg_i++) {
2585 int arg = bootstrap_argument_index_at(cp_index, arg_i);
2586 st->print((arg_i == 0 ? " arguments={%d" : ", %d"), arg);
2587 }
2588 st->print("}");
2589 }
2590 }
2591 break;
2592 default:
2593 ShouldNotReachHere();
2594 break;
2595 }
2596 st->cr();
2597 }
2598
2599 void ConstantPool::print_value_on(outputStream* st) const {
2600 assert(is_constantPool(), "must be constantPool");
2601 st->print("constant pool [%d]", length());
2602 if (has_preresolution()) st->print("/preresolution");
2603 if (operands() != nullptr) st->print("/operands[%d]", operands()->length());
2604 print_address_on(st);
2605 if (pool_holder() != nullptr) {
2606 st->print(" for ");
2607 pool_holder()->print_value_on(st);
2608 bool extra = (pool_holder()->constants() != this);
2609 if (extra) st->print(" (extra)");
2610 }
2611 if (cache() != nullptr) {
2612 st->print(" cache=" PTR_FORMAT, p2i(cache()));
2613 }
2614 }
2615
2616 // Verification
2617
2618 void ConstantPool::verify_on(outputStream* st) {
2619 guarantee(is_constantPool(), "object must be constant pool");
2620 for (int i = 0; i< length(); i++) {
2621 constantTag tag = tag_at(i);
2622 if (tag.is_klass() || tag.is_unresolved_klass()) {
2623 guarantee(klass_name_at(i)->refcount() != 0, "should have nonzero reference count");
2624 } else if (tag.is_symbol()) {
2625 Symbol* entry = symbol_at(i);
2626 guarantee(entry->refcount() != 0, "should have nonzero reference count");
2627 } else if (tag.is_string()) {
2628 Symbol* entry = unresolved_string_at(i);
2629 guarantee(entry->refcount() != 0, "should have nonzero reference count");
2630 }
2631 }
2632 if (pool_holder() != nullptr) {
2633 // Note: pool_holder() can be null in temporary constant pools
2634 // used during constant pool merging
2635 guarantee(pool_holder()->is_klass(), "should be klass");
2636 }
2637 }