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/fieldStreams.inline.hpp"
57 #include "oops/instanceKlass.hpp"
58 #include "oops/klass.inline.hpp"
59 #include "oops/objArrayKlass.hpp"
60 #include "oops/objArrayOop.inline.hpp"
61 #include "oops/oop.inline.hpp"
62 #include "oops/typeArrayOop.inline.hpp"
63 #include "prims/jvmtiExport.hpp"
64 #include "runtime/atomic.hpp"
65 #include "runtime/fieldDescriptor.inline.hpp"
66 #include "runtime/handles.inline.hpp"
67 #include "runtime/init.hpp"
68 #include "runtime/javaCalls.hpp"
69 #include "runtime/javaThread.inline.hpp"
70 #include "runtime/perfData.hpp"
71 #include "runtime/signature.hpp"
72 #include "runtime/vframe.inline.hpp"
73 #include "utilities/checkedCast.hpp"
74 #include "utilities/copy.hpp"
75
76 ConstantPool* ConstantPool::allocate(ClassLoaderData* loader_data, int length, TRAPS) {
77 Array<u1>* tags = MetadataFactory::new_array<u1>(loader_data, length, 0, CHECK_NULL);
78 int size = ConstantPool::size(length);
79 return new (loader_data, size, MetaspaceObj::ConstantPoolType, THREAD) ConstantPool(tags);
80 }
81
82 void ConstantPool::copy_fields(const ConstantPool* orig) {
83 // Preserve dynamic constant information from the original pool
84 if (orig->has_dynamic_constant()) {
85 set_has_dynamic_constant();
86 }
87
88 set_major_version(orig->major_version());
89 set_minor_version(orig->minor_version());
90
91 set_source_file_name_index(orig->source_file_name_index());
92 set_generic_signature_index(orig->generic_signature_index());
93 }
94
95 #ifdef ASSERT
96
97 // MetaspaceObj allocation invariant is calloc equivalent memory
98 // simple verification of this here (JVM_CONSTANT_Invalid == 0 )
99 static bool tag_array_is_zero_initialized(Array<u1>* tags) {
100 assert(tags != nullptr, "invariant");
101 const int length = tags->length();
102 for (int index = 0; index < length; ++index) {
103 if (JVM_CONSTANT_Invalid != tags->at(index)) {
104 return false;
105 }
106 }
107 return true;
108 }
109
110 #endif
111
112 ConstantPool::ConstantPool() {
113 assert(CDSConfig::is_dumping_static_archive() || CDSConfig::is_using_archive(), "only for CDS");
114 }
115
116 ConstantPool::ConstantPool(Array<u1>* tags) :
117 _tags(tags),
118 _length(tags->length()) {
119
120 assert(_tags != nullptr, "invariant");
121 assert(tags->length() == _length, "invariant");
122 assert(tag_array_is_zero_initialized(tags), "invariant");
123 assert(0 == flags(), "invariant");
124 assert(0 == version(), "invariant");
125 assert(nullptr == _pool_holder, "invariant");
126 }
127
128 void ConstantPool::deallocate_contents(ClassLoaderData* loader_data) {
129 if (cache() != nullptr) {
130 MetadataFactory::free_metadata(loader_data, cache());
131 set_cache(nullptr);
132 }
133
134 MetadataFactory::free_array<Klass*>(loader_data, resolved_klasses());
135 set_resolved_klasses(nullptr);
136
137 MetadataFactory::free_array<jushort>(loader_data, operands());
138 set_operands(nullptr);
139
140 release_C_heap_structures();
141
142 // free tag array
143 MetadataFactory::free_array<u1>(loader_data, tags());
144 set_tags(nullptr);
145 }
146
147 void ConstantPool::release_C_heap_structures() {
148 // walk constant pool and decrement symbol reference counts
149 unreference_symbols();
150 }
151
152 void ConstantPool::metaspace_pointers_do(MetaspaceClosure* it) {
153 log_trace(cds)("Iter(ConstantPool): %p", this);
154
155 it->push(&_tags, MetaspaceClosure::_writable);
156 it->push(&_cache);
157 it->push(&_pool_holder);
158 it->push(&_operands);
159 it->push(&_resolved_klasses, MetaspaceClosure::_writable);
160
161 for (int i = 0; i < length(); i++) {
162 // The only MSO's embedded in the CP entries are Symbols:
163 // JVM_CONSTANT_String
164 // JVM_CONSTANT_Utf8
165 constantTag ctag = tag_at(i);
166 if (ctag.is_string() || ctag.is_utf8()) {
167 it->push(symbol_at_addr(i));
168 }
169 }
170 }
171
172 objArrayOop ConstantPool::resolved_references() const {
173 return _cache->resolved_references();
174 }
175
176 // Called from outside constant pool resolution where a resolved_reference array
177 // may not be present.
178 objArrayOop ConstantPool::resolved_references_or_null() const {
179 if (_cache == nullptr) {
180 return nullptr;
181 } else {
182 return _cache->resolved_references();
183 }
184 }
185
186 oop ConstantPool::resolved_reference_at(int index) const {
187 oop result = resolved_references()->obj_at(index);
188 assert(oopDesc::is_oop_or_null(result), "Must be oop");
189 return result;
190 }
191
192 // Use a CAS for multithreaded access
193 oop ConstantPool::set_resolved_reference_at(int index, oop new_result) {
194 assert(oopDesc::is_oop_or_null(new_result), "Must be oop");
195 return resolved_references()->replace_if_null(index, new_result);
196 }
197
198 // Create resolved_references array and mapping array for original cp indexes
199 // The ldc bytecode was rewritten to have the resolved reference array index so need a way
200 // to map it back for resolving and some unlikely miscellaneous uses.
201 // The objects created by invokedynamic are appended to this list.
202 void ConstantPool::initialize_resolved_references(ClassLoaderData* loader_data,
203 const intStack& reference_map,
204 int constant_pool_map_length,
205 TRAPS) {
206 // Initialized the resolved object cache.
207 int map_length = reference_map.length();
208 if (map_length > 0) {
209 // Only need mapping back to constant pool entries. The map isn't used for
210 // invokedynamic resolved_reference entries. For invokedynamic entries,
211 // the constant pool cache index has the mapping back to both the constant
212 // pool and to the resolved reference index.
213 if (constant_pool_map_length > 0) {
214 Array<u2>* om = MetadataFactory::new_array<u2>(loader_data, constant_pool_map_length, CHECK);
215
216 for (int i = 0; i < constant_pool_map_length; i++) {
217 int x = reference_map.at(i);
218 assert(x == (int)(jushort) x, "klass index is too big");
219 om->at_put(i, (jushort)x);
220 }
221 set_reference_map(om);
222 }
223
224 // Create Java array for holding resolved strings, methodHandles,
225 // methodTypes, invokedynamic and invokehandle appendix objects, etc.
226 objArrayOop stom = oopFactory::new_objArray(vmClasses::Object_klass(), map_length, CHECK);
227 HandleMark hm(THREAD);
228 Handle refs_handle (THREAD, stom); // must handleize.
229 set_resolved_references(loader_data->add_handle(refs_handle));
230
231 // Create a "scratch" copy of the resolved references array to archive
232 if (CDSConfig::is_dumping_heap()) {
233 objArrayOop scratch_references = oopFactory::new_objArray(vmClasses::Object_klass(), map_length, CHECK);
234 HeapShared::add_scratch_resolved_references(this, scratch_references);
235 }
236 }
237 }
238
239 void ConstantPool::allocate_resolved_klasses(ClassLoaderData* loader_data, int num_klasses, TRAPS) {
240 // A ConstantPool can't possibly have 0xffff valid class entries,
241 // because entry #0 must be CONSTANT_Invalid, and each class entry must refer to a UTF8
242 // entry for the class's name. So at most we will have 0xfffe class entries.
243 // This allows us to use 0xffff (ConstantPool::_temp_resolved_klass_index) to indicate
244 // UnresolvedKlass entries that are temporarily created during class redefinition.
245 assert(num_klasses < CPKlassSlot::_temp_resolved_klass_index, "sanity");
246 assert(resolved_klasses() == nullptr, "sanity");
247 Array<Klass*>* rk = MetadataFactory::new_array<Klass*>(loader_data, num_klasses, CHECK);
248 set_resolved_klasses(rk);
249 }
250
251 void ConstantPool::initialize_unresolved_klasses(ClassLoaderData* loader_data, TRAPS) {
252 int len = length();
253 int num_klasses = 0;
254 for (int i = 1; i <len; i++) {
255 switch (tag_at(i).value()) {
256 case JVM_CONSTANT_ClassIndex:
257 {
258 const int class_index = klass_index_at(i);
259 unresolved_klass_at_put(i, class_index, num_klasses++);
260 }
261 break;
262 #ifndef PRODUCT
263 case JVM_CONSTANT_Class:
264 case JVM_CONSTANT_UnresolvedClass:
265 case JVM_CONSTANT_UnresolvedClassInError:
266 // All of these should have been reverted back to ClassIndex before calling
267 // this function.
268 ShouldNotReachHere();
269 #endif
270 }
271 }
272 allocate_resolved_klasses(loader_data, num_klasses, THREAD);
273 }
274
275 // Hidden class support:
276 void ConstantPool::klass_at_put(int class_index, Klass* k) {
277 assert(k != nullptr, "must be valid klass");
278 CPKlassSlot kslot = klass_slot_at(class_index);
279 int resolved_klass_index = kslot.resolved_klass_index();
280 Klass** adr = resolved_klasses()->adr_at(resolved_klass_index);
281 Atomic::release_store(adr, k);
282
283 // The interpreter assumes when the tag is stored, the klass is resolved
284 // and the Klass* non-null, so we need hardware store ordering here.
285 release_tag_at_put(class_index, JVM_CONSTANT_Class);
286 }
287
288 #if INCLUDE_CDS_JAVA_HEAP
289 template <typename Function>
290 void ConstantPool::iterate_archivable_resolved_references(Function function) {
291 objArrayOop rr = resolved_references();
292 if (rr != nullptr && cache() != nullptr && CDSConfig::is_dumping_invokedynamic()) {
293 Array<ResolvedIndyEntry>* indy_entries = cache()->resolved_indy_entries();
294 if (indy_entries != nullptr) {
295 for (int i = 0; i < indy_entries->length(); i++) {
296 ResolvedIndyEntry *rie = indy_entries->adr_at(i);
297 if (rie->is_resolved() && AOTConstantPoolResolver::is_resolution_deterministic(this, rie->constant_pool_index())) {
298 int rr_index = rie->resolved_references_index();
299 assert(resolved_reference_at(rr_index) != nullptr, "must exist");
300 function(rr_index);
301
302 // Save the BSM as well (sometimes the JIT looks up the BSM it for replay)
303 int indy_cp_index = rie->constant_pool_index();
304 int bsm_mh_cp_index = bootstrap_method_ref_index_at(indy_cp_index);
305 int bsm_rr_index = cp_to_object_index(bsm_mh_cp_index);
306 assert(resolved_reference_at(bsm_rr_index) != nullptr, "must exist");
307 function(bsm_rr_index);
308 }
309 }
310 }
311
312 Array<ResolvedMethodEntry>* method_entries = cache()->resolved_method_entries();
313 if (method_entries != nullptr) {
314 for (int i = 0; i < method_entries->length(); i++) {
315 ResolvedMethodEntry* rme = method_entries->adr_at(i);
316 if (rme->is_resolved(Bytecodes::_invokehandle) && rme->has_appendix() &&
317 cache()->can_archive_resolved_method(this, rme)) {
318 int rr_index = rme->resolved_references_index();
319 assert(resolved_reference_at(rr_index) != nullptr, "must exist");
320 function(rr_index);
321 }
322 }
323 }
324 }
325 }
326
327 // Returns the _resolved_reference array after removing unarchivable items from it.
328 // Returns null if this class is not supported, or _resolved_reference doesn't exist.
329 objArrayOop ConstantPool::prepare_resolved_references_for_archiving() {
330 if (_cache == nullptr) {
331 return nullptr; // nothing to do
332 }
333
334 InstanceKlass *ik = pool_holder();
335 if (!(ik->is_shared_boot_class() || ik->is_shared_platform_class() ||
336 ik->is_shared_app_class())) {
337 // Archiving resolved references for classes from non-builtin loaders
338 // is not yet supported.
339 return nullptr;
340 }
341
342 objArrayOop rr = resolved_references();
343 if (rr != nullptr) {
344 ResourceMark rm;
345 int rr_len = rr->length();
346 GrowableArray<bool> keep_resolved_refs(rr_len, rr_len, false);
347
348 ConstantPool* src_cp = ArchiveBuilder::current()->get_source_addr(this);
349 src_cp->iterate_archivable_resolved_references([&](int rr_index) {
350 keep_resolved_refs.at_put(rr_index, true);
351 });
352
353 objArrayOop scratch_rr = HeapShared::scratch_resolved_references(src_cp);
354 Array<u2>* ref_map = reference_map();
355 int ref_map_len = ref_map == nullptr ? 0 : ref_map->length();
356 for (int i = 0; i < rr_len; i++) {
357 oop obj = rr->obj_at(i);
358 scratch_rr->obj_at_put(i, nullptr);
359 if (obj != nullptr) {
360 if (i < ref_map_len) {
361 int index = object_to_cp_index(i);
362 if (tag_at(index).is_string()) {
363 assert(java_lang_String::is_instance(obj), "must be");
364 if (!ArchiveHeapWriter::is_string_too_large_to_archive(obj)) {
365 scratch_rr->obj_at_put(i, obj);
366 }
367 continue;
368 }
369 }
370
371 if (keep_resolved_refs.at(i)) {
372 scratch_rr->obj_at_put(i, obj);
373 }
374 }
375 }
376 return scratch_rr;
377 }
378 return rr;
379 }
380
381 void ConstantPool::find_required_hidden_classes() {
382 if (_cache == nullptr) {
383 return;
384 }
385
386 ClassLoaderData* loader_data = pool_holder()->class_loader_data();
387 if (loader_data == nullptr) {
388 // These are custom loader classes from the preimage
389 return;
390 }
391
392 if (!SystemDictionaryShared::is_builtin_loader(loader_data)) {
393 // Archiving resolved references for classes from non-builtin loaders
394 // is not yet supported.
395 return;
396 }
397
398 objArrayOop rr = resolved_references();
399 if (rr != nullptr) {
400 iterate_archivable_resolved_references([&](int rr_index) {
401 oop obj = rr->obj_at(rr_index);
402 HeapShared::find_required_hidden_classes_in_object(obj);
403 });
404 }
405 }
406
407 void ConstantPool::add_dumped_interned_strings() {
408 InstanceKlass* ik = pool_holder();
409 if (!ik->is_linked()) {
410 // resolved_references() doesn't exist yet, so we have no resolved CONSTANT_String entries. However,
411 // some static final fields may have default values that were initialized when the class was parsed.
412 // We need to enter those into the CDS archive strings table.
413 for (JavaFieldStream fs(ik); !fs.done(); fs.next()) {
414 if (fs.access_flags().is_static()) {
415 fieldDescriptor& fd = fs.field_descriptor();
416 if (fd.field_type() == T_OBJECT) {
417 int offset = fd.offset();
418 check_and_add_dumped_interned_string(ik->java_mirror()->obj_field(offset));
419 }
420 }
421 }
422 } else {
423 objArrayOop rr = resolved_references();
424 if (rr != nullptr) {
425 int rr_len = rr->length();
426 for (int i = 0; i < rr_len; i++) {
427 check_and_add_dumped_interned_string(rr->obj_at(i));
428 }
429 }
430 }
431 }
432
433 void ConstantPool::check_and_add_dumped_interned_string(oop obj) {
434 if (obj != nullptr && java_lang_String::is_instance(obj) &&
435 !ArchiveHeapWriter::is_string_too_large_to_archive(obj)) {
436 HeapShared::add_to_dumped_interned_strings(obj);
437 }
438 }
439
440 #endif
441
442 #if INCLUDE_CDS
443 // CDS support. Create a new resolved_references array.
444 void ConstantPool::restore_unshareable_info(TRAPS) {
445 if (!_pool_holder->is_linked() && !_pool_holder->is_rewritten()) {
446 return;
447 }
448 assert(is_constantPool(), "ensure C++ vtable is restored");
449 assert(on_stack(), "should always be set for shared constant pools");
450 assert(is_shared(), "should always be set for shared constant pools");
451 if (is_for_method_handle_intrinsic()) {
452 // See the same check in remove_unshareable_info() below.
453 assert(cache() == nullptr, "must not have cpCache");
454 return;
455 }
456 assert(_cache != nullptr, "constant pool _cache should not be null");
457
458 // Only create the new resolved references array if it hasn't been attempted before
459 if (resolved_references() != nullptr) return;
460
461 if (vmClasses::Object_klass_loaded()) {
462 ClassLoaderData* loader_data = pool_holder()->class_loader_data();
463 #if INCLUDE_CDS_JAVA_HEAP
464 if (ArchiveHeapLoader::is_in_use() &&
465 _cache->archived_references() != nullptr) {
466 oop archived = _cache->archived_references();
467 // Create handle for the archived resolved reference array object
468 HandleMark hm(THREAD);
469 Handle refs_handle(THREAD, archived);
470 set_resolved_references(loader_data->add_handle(refs_handle));
471 _cache->clear_archived_references();
472 } else
473 #endif
474 {
475 // No mapped archived resolved reference array
476 // Recreate the object array and add to ClassLoaderData.
477 int map_length = resolved_reference_length();
478 if (map_length > 0) {
479 objArrayOop stom = oopFactory::new_objArray(vmClasses::Object_klass(), map_length, CHECK);
480 HandleMark hm(THREAD);
481 Handle refs_handle(THREAD, stom); // must handleize.
482 set_resolved_references(loader_data->add_handle(refs_handle));
483 }
484 }
485 }
486 }
487
488 void ConstantPool::remove_unshareable_info() {
489 // Shared ConstantPools are in the RO region, so the _flags cannot be modified.
490 // The _on_stack flag is used to prevent ConstantPools from deallocation during
491 // class redefinition. Since shared ConstantPools cannot be deallocated anyway,
492 // we always set _on_stack to true to avoid having to change _flags during runtime.
493 _flags |= (_on_stack | _is_shared);
494
495 if (is_for_method_handle_intrinsic()) {
496 // This CP was created by Method::make_method_handle_intrinsic() and has nothing
497 // that need to be removed/restored. It has no cpCache since the intrinsic methods
498 // don't have any bytecodes.
499 assert(cache() == nullptr, "must not have cpCache");
500 return;
501 }
502
503 // resolved_references(): remember its length. If it cannot be restored
504 // from the archived heap objects at run time, we need to dynamically allocate it.
505 if (cache() != nullptr) {
506 set_resolved_reference_length(
507 resolved_references() != nullptr ? resolved_references()->length() : 0);
508 set_resolved_references(OopHandle());
509 }
510 remove_unshareable_entries();
511 }
512
513 static const char* get_type(Klass* k) {
514 const char* type;
515 Klass* src_k;
516 if (ArchiveBuilder::is_active() && ArchiveBuilder::current()->is_in_buffer_space(k)) {
517 src_k = ArchiveBuilder::current()->get_source_addr(k);
518 } else {
519 src_k = k;
520 }
521
522 if (src_k->is_objArray_klass()) {
523 src_k = ObjArrayKlass::cast(src_k)->bottom_klass();
524 assert(!src_k->is_objArray_klass(), "sanity");
525 }
526
527 if (src_k->is_typeArray_klass()) {
528 type = "prim";
529 } else {
530 InstanceKlass* src_ik = InstanceKlass::cast(src_k);
531 oop loader = src_ik->class_loader();
532 if (loader == nullptr) {
533 type = "boot";
534 } else if (loader == SystemDictionary::java_platform_loader()) {
535 type = "plat";
536 } else if (loader == SystemDictionary::java_system_loader()) {
537 type = "app";
538 } else {
539 type = "unreg";
540 }
541 }
542
543 return type;
544 }
545
546 void ConstantPool::remove_unshareable_entries() {
547 ResourceMark rm;
548 log_info(cds, resolve)("Archiving CP entries for %s", pool_holder()->name()->as_C_string());
549 for (int cp_index = 1; cp_index < length(); cp_index++) { // cp_index 0 is unused
550 int cp_tag = tag_at(cp_index).value();
551 switch (cp_tag) {
552 case JVM_CONSTANT_UnresolvedClass:
553 ArchiveBuilder::alloc_stats()->record_klass_cp_entry(false, false);
554 break;
555 case JVM_CONSTANT_UnresolvedClassInError:
556 tag_at_put(cp_index, JVM_CONSTANT_UnresolvedClass);
557 ArchiveBuilder::alloc_stats()->record_klass_cp_entry(false, true);
558 break;
559 case JVM_CONSTANT_MethodHandleInError:
560 tag_at_put(cp_index, JVM_CONSTANT_MethodHandle);
561 break;
562 case JVM_CONSTANT_MethodTypeInError:
563 tag_at_put(cp_index, JVM_CONSTANT_MethodType);
564 break;
565 case JVM_CONSTANT_DynamicInError:
566 tag_at_put(cp_index, JVM_CONSTANT_Dynamic);
567 break;
568 case JVM_CONSTANT_Class:
569 remove_resolved_klass_if_non_deterministic(cp_index);
570 break;
571 default:
572 break;
573 }
574 }
575
576 if (cache() != nullptr) {
577 // cache() is null if this class is not yet linked.
578 cache()->remove_unshareable_info();
579 }
580 }
581
582 void ConstantPool::remove_resolved_klass_if_non_deterministic(int cp_index) {
583 assert(ArchiveBuilder::current()->is_in_buffer_space(this), "must be");
584 assert(tag_at(cp_index).is_klass(), "must be resolved");
585
586 Klass* k = resolved_klass_at(cp_index);
587 bool can_archive;
588
589 if (k == nullptr) {
590 // We'd come here if the referenced class has been excluded via
591 // SystemDictionaryShared::is_excluded_class(). As a result, ArchiveBuilder
592 // has cleared the resolved_klasses()->at(...) pointer to null. Thus, we
593 // need to revert the tag to JVM_CONSTANT_UnresolvedClass.
594 can_archive = false;
595 } else {
596 ConstantPool* src_cp = ArchiveBuilder::current()->get_source_addr(this);
597 can_archive = AOTConstantPoolResolver::is_resolution_deterministic(src_cp, cp_index);
598 }
599
600 if (!can_archive) {
601 int resolved_klass_index = klass_slot_at(cp_index).resolved_klass_index();
602 resolved_klasses()->at_put(resolved_klass_index, nullptr);
603 tag_at_put(cp_index, JVM_CONSTANT_UnresolvedClass);
604 }
605
606 LogStreamHandle(Trace, cds, resolve) log;
607 if (log.is_enabled()) {
608 ResourceMark rm;
609 log.print("%s klass CP entry [%3d]: %s %s",
610 (can_archive ? "archived" : "reverted"),
611 cp_index, pool_holder()->name()->as_C_string(), get_type(pool_holder()));
612 if (can_archive) {
613 log.print(" => %s %s%s", k->name()->as_C_string(), get_type(k),
614 (!k->is_instance_klass() || pool_holder()->is_subtype_of(k)) ? "" : " (not supertype)");
615 } else {
616 Symbol* name = klass_name_at(cp_index);
617 log.print(" => %s", name->as_C_string());
618 }
619 }
620
621 ArchiveBuilder::alloc_stats()->record_klass_cp_entry(can_archive, /*reverted=*/!can_archive);
622 }
623 #endif // INCLUDE_CDS
624
625 int ConstantPool::cp_to_object_index(int cp_index) {
626 // this is harder don't do this so much.
627 int i = reference_map()->find(checked_cast<u2>(cp_index));
628 // We might not find the index for jsr292 call.
629 return (i < 0) ? _no_index_sentinel : i;
630 }
631
632 void ConstantPool::string_at_put(int obj_index, oop str) {
633 oop result = set_resolved_reference_at(obj_index, str);
634 assert(result == nullptr || result == str, "Only set once or to the same string.");
635 }
636
637 void ConstantPool::trace_class_resolution(const constantPoolHandle& this_cp, Klass* k) {
638 ResourceMark rm;
639 int line_number = -1;
640 const char * source_file = nullptr;
641 if (JavaThread::current()->has_last_Java_frame()) {
642 // try to identify the method which called this function.
643 vframeStream vfst(JavaThread::current());
644 if (!vfst.at_end()) {
645 line_number = vfst.method()->line_number_from_bci(vfst.bci());
646 Symbol* s = vfst.method()->method_holder()->source_file_name();
647 if (s != nullptr) {
648 source_file = s->as_C_string();
649 }
650 }
651 }
652 if (k != this_cp->pool_holder()) {
653 // only print something if the classes are different
654 if (source_file != nullptr) {
655 log_debug(class, resolve)("%s %s %s:%d",
656 this_cp->pool_holder()->external_name(),
657 k->external_name(), source_file, line_number);
658 } else {
659 log_debug(class, resolve)("%s %s",
660 this_cp->pool_holder()->external_name(),
661 k->external_name());
662 }
663 }
664 }
665
666 Klass* ConstantPool::klass_at_impl(const constantPoolHandle& this_cp, int cp_index,
667 TRAPS) {
668 JavaThread* javaThread = THREAD;
669
670 // A resolved constantPool entry will contain a Klass*, otherwise a Symbol*.
671 // It is not safe to rely on the tag bit's here, since we don't have a lock, and
672 // the entry and tag is not updated atomically.
673 CPKlassSlot kslot = this_cp->klass_slot_at(cp_index);
674 int resolved_klass_index = kslot.resolved_klass_index();
675 int name_index = kslot.name_index();
676 assert(this_cp->tag_at(name_index).is_symbol(), "sanity");
677
678 // The tag must be JVM_CONSTANT_Class in order to read the correct value from
679 // the unresolved_klasses() array.
680 if (this_cp->tag_at(cp_index).is_klass()) {
681 Klass* klass = this_cp->resolved_klasses()->at(resolved_klass_index);
682 if (klass != nullptr) {
683 return klass;
684 }
685 }
686
687 // This tag doesn't change back to unresolved class unless at a safepoint.
688 if (this_cp->tag_at(cp_index).is_unresolved_klass_in_error()) {
689 // The original attempt to resolve this constant pool entry failed so find the
690 // class of the original error and throw another error of the same class
691 // (JVMS 5.4.3).
692 // If there is a detail message, pass that detail message to the error.
693 // The JVMS does not strictly require us to duplicate the same detail message,
694 // or any internal exception fields such as cause or stacktrace. But since the
695 // detail message is often a class name or other literal string, we will repeat it
696 // if we can find it in the symbol table.
697 throw_resolution_error(this_cp, cp_index, CHECK_NULL);
698 ShouldNotReachHere();
699 }
700
701 HandleMark hm(THREAD);
702 Handle mirror_handle;
703 Symbol* name = this_cp->symbol_at(name_index);
704 Handle loader (THREAD, this_cp->pool_holder()->class_loader());
705
706 Klass* k;
707 {
708 // Turn off the single stepping while doing class resolution
709 JvmtiHideSingleStepping jhss(javaThread);
710 k = SystemDictionary::resolve_or_fail(name, loader, true, THREAD);
711 } // JvmtiHideSingleStepping jhss(javaThread);
712
713 if (!HAS_PENDING_EXCEPTION) {
714 // preserve the resolved klass from unloading
715 mirror_handle = Handle(THREAD, k->java_mirror());
716 // Do access check for klasses
717 verify_constant_pool_resolve(this_cp, k, THREAD);
718 }
719
720 // Failed to resolve class. We must record the errors so that subsequent attempts
721 // to resolve this constant pool entry fail with the same error (JVMS 5.4.3).
722 if (HAS_PENDING_EXCEPTION) {
723 save_and_throw_exception(this_cp, cp_index, constantTag(JVM_CONSTANT_UnresolvedClass), CHECK_NULL);
724 // If CHECK_NULL above doesn't return the exception, that means that
725 // some other thread has beaten us and has resolved the class.
726 // To preserve old behavior, we return the resolved class.
727 Klass* klass = this_cp->resolved_klasses()->at(resolved_klass_index);
728 assert(klass != nullptr, "must be resolved if exception was cleared");
729 return klass;
730 }
731
732 // logging for class+resolve.
733 if (log_is_enabled(Debug, class, resolve)){
734 trace_class_resolution(this_cp, k);
735 }
736
737 Klass** adr = this_cp->resolved_klasses()->adr_at(resolved_klass_index);
738 Atomic::release_store(adr, k);
739 // The interpreter assumes when the tag is stored, the klass is resolved
740 // and the Klass* stored in _resolved_klasses is non-null, so we need
741 // hardware store ordering here.
742 // We also need to CAS to not overwrite an error from a racing thread.
743
744 jbyte old_tag = Atomic::cmpxchg((jbyte*)this_cp->tag_addr_at(cp_index),
745 (jbyte)JVM_CONSTANT_UnresolvedClass,
746 (jbyte)JVM_CONSTANT_Class);
747
748 // We need to recheck exceptions from racing thread and return the same.
749 if (old_tag == JVM_CONSTANT_UnresolvedClassInError) {
750 // Remove klass.
751 this_cp->resolved_klasses()->at_put(resolved_klass_index, nullptr);
752 throw_resolution_error(this_cp, cp_index, CHECK_NULL);
753 }
754
755 return k;
756 }
757
758
759 // Does not update ConstantPool* - to avoid any exception throwing. Used
760 // by compiler and exception handling. Also used to avoid classloads for
761 // instanceof operations. Returns null if the class has not been loaded or
762 // if the verification of constant pool failed
763 Klass* ConstantPool::klass_at_if_loaded(const constantPoolHandle& this_cp, int which) {
764 CPKlassSlot kslot = this_cp->klass_slot_at(which);
765 int resolved_klass_index = kslot.resolved_klass_index();
766 int name_index = kslot.name_index();
767 assert(this_cp->tag_at(name_index).is_symbol(), "sanity");
768
769 if (this_cp->tag_at(which).is_klass()) {
770 Klass* k = this_cp->resolved_klasses()->at(resolved_klass_index);
771 assert(k != nullptr, "should be resolved");
772 return k;
773 } else if (this_cp->tag_at(which).is_unresolved_klass_in_error()) {
774 return nullptr;
775 } else {
776 Thread* current = Thread::current();
777 HandleMark hm(current);
778 Symbol* name = this_cp->symbol_at(name_index);
779 oop loader = this_cp->pool_holder()->class_loader();
780 Handle h_loader (current, loader);
781 Klass* k = SystemDictionary::find_instance_klass(current, name, h_loader);
782
783 // Avoid constant pool verification at a safepoint, as it takes the Module_lock.
784 if (k != nullptr && current->is_Java_thread()) {
785 // Make sure that resolving is legal
786 JavaThread* THREAD = JavaThread::cast(current); // For exception macros.
787 ExceptionMark em(THREAD);
788 // return null if verification fails
789 verify_constant_pool_resolve(this_cp, k, THREAD);
790 if (HAS_PENDING_EXCEPTION) {
791 CLEAR_PENDING_EXCEPTION;
792 return nullptr;
793 }
794 return k;
795 } else {
796 return k;
797 }
798 }
799 }
800
801 Method* ConstantPool::method_at_if_loaded(const constantPoolHandle& cpool,
802 int which) {
803 if (cpool->cache() == nullptr) return nullptr; // nothing to load yet
804 if (!(which >= 0 && which < cpool->resolved_method_entries_length())) {
805 // FIXME: should be an assert
806 log_debug(class, resolve)("bad operand %d in:", which); cpool->print();
807 return nullptr;
808 }
809 return cpool->cache()->method_if_resolved(which);
810 }
811
812
813 bool ConstantPool::has_appendix_at_if_loaded(const constantPoolHandle& cpool, int which, Bytecodes::Code code) {
814 if (cpool->cache() == nullptr) return false; // nothing to load yet
815 if (code == Bytecodes::_invokedynamic) {
816 return cpool->resolved_indy_entry_at(which)->has_appendix();
817 } else {
818 return cpool->resolved_method_entry_at(which)->has_appendix();
819 }
820 }
821
822 oop ConstantPool::appendix_at_if_loaded(const constantPoolHandle& cpool, int which, Bytecodes::Code code) {
823 if (cpool->cache() == nullptr) return nullptr; // nothing to load yet
824 if (code == Bytecodes::_invokedynamic) {
825 return cpool->resolved_reference_from_indy(which);
826 } else {
827 return cpool->cache()->appendix_if_resolved(which);
828 }
829 }
830
831
832 bool ConstantPool::has_local_signature_at_if_loaded(const constantPoolHandle& cpool, int which, Bytecodes::Code code) {
833 if (cpool->cache() == nullptr) return false; // nothing to load yet
834 if (code == Bytecodes::_invokedynamic) {
835 return cpool->resolved_indy_entry_at(which)->has_local_signature();
836 } else {
837 return cpool->resolved_method_entry_at(which)->has_local_signature();
838 }
839 }
840
841 // Translate index, which could be CPCache index or Indy index, to a constant pool index
842 int ConstantPool::to_cp_index(int index, Bytecodes::Code code) {
843 assert(cache() != nullptr, "'index' is a rewritten index so this class must have been rewritten");
844 switch(code) {
845 case Bytecodes::_invokedynamic:
846 return invokedynamic_bootstrap_ref_index_at(index);
847 case Bytecodes::_getfield:
848 case Bytecodes::_getstatic:
849 case Bytecodes::_putfield:
850 case Bytecodes::_putstatic:
851 return resolved_field_entry_at(index)->constant_pool_index();
852 case Bytecodes::_invokeinterface:
853 case Bytecodes::_invokehandle:
854 case Bytecodes::_invokespecial:
855 case Bytecodes::_invokestatic:
856 case Bytecodes::_invokevirtual:
857 case Bytecodes::_fast_invokevfinal: // Bytecode interpreter uses this
858 return resolved_method_entry_at(index)->constant_pool_index();
859 default:
860 fatal("Unexpected bytecode: %s", Bytecodes::name(code));
861 }
862 }
863
864 bool ConstantPool::is_resolved(int index, Bytecodes::Code code) {
865 assert(cache() != nullptr, "'index' is a rewritten index so this class must have been rewritten");
866 switch(code) {
867 case Bytecodes::_invokedynamic:
868 return resolved_indy_entry_at(index)->is_resolved();
869
870 case Bytecodes::_getfield:
871 case Bytecodes::_getstatic:
872 case Bytecodes::_putfield:
873 case Bytecodes::_putstatic:
874 return resolved_field_entry_at(index)->is_resolved(code);
875
876 case Bytecodes::_invokeinterface:
877 case Bytecodes::_invokehandle:
878 case Bytecodes::_invokespecial:
879 case Bytecodes::_invokestatic:
880 case Bytecodes::_invokevirtual:
881 case Bytecodes::_fast_invokevfinal: // Bytecode interpreter uses this
882 return resolved_method_entry_at(index)->is_resolved(code);
883
884 default:
885 fatal("Unexpected bytecode: %s", Bytecodes::name(code));
886 }
887 }
888
889 u2 ConstantPool::uncached_name_and_type_ref_index_at(int cp_index) {
890 if (tag_at(cp_index).has_bootstrap()) {
891 u2 pool_index = bootstrap_name_and_type_ref_index_at(cp_index);
892 assert(tag_at(pool_index).is_name_and_type(), "");
893 return pool_index;
894 }
895 assert(tag_at(cp_index).is_field_or_method(), "Corrupted constant pool");
896 assert(!tag_at(cp_index).has_bootstrap(), "Must be handled above");
897 jint ref_index = *int_at_addr(cp_index);
898 return extract_high_short_from_int(ref_index);
899 }
900
901 u2 ConstantPool::name_and_type_ref_index_at(int index, Bytecodes::Code code) {
902 return uncached_name_and_type_ref_index_at(to_cp_index(index, code));
903 }
904
905 constantTag ConstantPool::tag_ref_at(int which, Bytecodes::Code code) {
906 // which may be either a Constant Pool index or a rewritten index
907 int pool_index = which;
908 assert(cache() != nullptr, "'index' is a rewritten index so this class must have been rewritten");
909 pool_index = to_cp_index(which, code);
910 return tag_at(pool_index);
911 }
912
913 u2 ConstantPool::uncached_klass_ref_index_at(int cp_index) {
914 assert(tag_at(cp_index).is_field_or_method(), "Corrupted constant pool");
915 jint ref_index = *int_at_addr(cp_index);
916 return extract_low_short_from_int(ref_index);
917 }
918
919 u2 ConstantPool::klass_ref_index_at(int index, Bytecodes::Code code) {
920 assert(code != Bytecodes::_invokedynamic,
921 "an invokedynamic instruction does not have a klass");
922 return uncached_klass_ref_index_at(to_cp_index(index, code));
923 }
924
925 void ConstantPool::verify_constant_pool_resolve(const constantPoolHandle& this_cp, Klass* k, TRAPS) {
926 if (!(k->is_instance_klass() || k->is_objArray_klass())) {
927 return; // short cut, typeArray klass is always accessible
928 }
929 Klass* holder = this_cp->pool_holder();
930 LinkResolver::check_klass_accessibility(holder, k, CHECK);
931 }
932
933
934 u2 ConstantPool::name_ref_index_at(int cp_index) {
935 jint ref_index = name_and_type_at(cp_index);
936 return extract_low_short_from_int(ref_index);
937 }
938
939
940 u2 ConstantPool::signature_ref_index_at(int cp_index) {
941 jint ref_index = name_and_type_at(cp_index);
942 return extract_high_short_from_int(ref_index);
943 }
944
945
946 Klass* ConstantPool::klass_ref_at(int which, Bytecodes::Code code, TRAPS) {
947 return klass_at(klass_ref_index_at(which, code), THREAD);
948 }
949
950 Symbol* ConstantPool::klass_name_at(int cp_index) const {
951 return symbol_at(klass_slot_at(cp_index).name_index());
952 }
953
954 Symbol* ConstantPool::klass_ref_at_noresolve(int which, Bytecodes::Code code) {
955 jint ref_index = klass_ref_index_at(which, code);
956 return klass_at_noresolve(ref_index);
957 }
958
959 Symbol* ConstantPool::uncached_klass_ref_at_noresolve(int cp_index) {
960 jint ref_index = uncached_klass_ref_index_at(cp_index);
961 return klass_at_noresolve(ref_index);
962 }
963
964 char* ConstantPool::string_at_noresolve(int cp_index) {
965 return unresolved_string_at(cp_index)->as_C_string();
966 }
967
968 BasicType ConstantPool::basic_type_for_signature_at(int cp_index) const {
969 return Signature::basic_type(symbol_at(cp_index));
970 }
971
972
973 void ConstantPool::resolve_string_constants_impl(const constantPoolHandle& this_cp, TRAPS) {
974 for (int index = 1; index < this_cp->length(); index++) { // Index 0 is unused
975 if (this_cp->tag_at(index).is_string()) {
976 this_cp->string_at(index, CHECK);
977 }
978 }
979 }
980
981 static const char* exception_message(const constantPoolHandle& this_cp, int which, constantTag tag, oop pending_exception) {
982 // Note: caller needs ResourceMark
983
984 // Dig out the detailed message to reuse if possible
985 const char* msg = java_lang_Throwable::message_as_utf8(pending_exception);
986 if (msg != nullptr) {
987 return msg;
988 }
989
990 Symbol* message = nullptr;
991 // Return specific message for the tag
992 switch (tag.value()) {
993 case JVM_CONSTANT_UnresolvedClass:
994 // return the class name in the error message
995 message = this_cp->klass_name_at(which);
996 break;
997 case JVM_CONSTANT_MethodHandle:
998 // return the method handle name in the error message
999 message = this_cp->method_handle_name_ref_at(which);
1000 break;
1001 case JVM_CONSTANT_MethodType:
1002 // return the method type signature in the error message
1003 message = this_cp->method_type_signature_at(which);
1004 break;
1005 case JVM_CONSTANT_Dynamic:
1006 // return the name of the condy in the error message
1007 message = this_cp->uncached_name_ref_at(which);
1008 break;
1009 default:
1010 ShouldNotReachHere();
1011 }
1012
1013 return message != nullptr ? message->as_C_string() : nullptr;
1014 }
1015
1016 static void add_resolution_error(JavaThread* current, const constantPoolHandle& this_cp, int which,
1017 constantTag tag, oop pending_exception) {
1018
1019 ResourceMark rm(current);
1020 Symbol* error = pending_exception->klass()->name();
1021 oop cause = java_lang_Throwable::cause(pending_exception);
1022
1023 // Also dig out the exception cause, if present.
1024 Symbol* cause_sym = nullptr;
1025 const char* cause_msg = nullptr;
1026 if (cause != nullptr && cause != pending_exception) {
1027 cause_sym = cause->klass()->name();
1028 cause_msg = java_lang_Throwable::message_as_utf8(cause);
1029 }
1030
1031 const char* message = exception_message(this_cp, which, tag, pending_exception);
1032 SystemDictionary::add_resolution_error(this_cp, which, error, message, cause_sym, cause_msg);
1033 }
1034
1035
1036 void ConstantPool::throw_resolution_error(const constantPoolHandle& this_cp, int which, TRAPS) {
1037 ResourceMark rm(THREAD);
1038 const char* message = nullptr;
1039 Symbol* cause = nullptr;
1040 const char* cause_msg = nullptr;
1041 Symbol* error = SystemDictionary::find_resolution_error(this_cp, which, &message, &cause, &cause_msg);
1042 assert(error != nullptr, "checking");
1043
1044 CLEAR_PENDING_EXCEPTION;
1045 if (message != nullptr) {
1046 if (cause != nullptr) {
1047 Handle h_cause = Exceptions::new_exception(THREAD, cause, cause_msg);
1048 THROW_MSG_CAUSE(error, message, h_cause);
1049 } else {
1050 THROW_MSG(error, message);
1051 }
1052 } else {
1053 if (cause != nullptr) {
1054 Handle h_cause = Exceptions::new_exception(THREAD, cause, cause_msg);
1055 THROW_CAUSE(error, h_cause);
1056 } else {
1057 THROW(error);
1058 }
1059 }
1060 }
1061
1062 // If resolution for Class, Dynamic constant, MethodHandle or MethodType fails, save the
1063 // exception in the resolution error table, so that the same exception is thrown again.
1064 void ConstantPool::save_and_throw_exception(const constantPoolHandle& this_cp, int cp_index,
1065 constantTag tag, TRAPS) {
1066
1067 int error_tag = tag.error_value();
1068
1069 if (!PENDING_EXCEPTION->
1070 is_a(vmClasses::LinkageError_klass())) {
1071 // Just throw the exception and don't prevent these classes from
1072 // being loaded due to virtual machine errors like StackOverflow
1073 // and OutOfMemoryError, etc, or if the thread was hit by stop()
1074 // Needs clarification to section 5.4.3 of the VM spec (see 6308271)
1075 } else if (this_cp->tag_at(cp_index).value() != error_tag) {
1076 add_resolution_error(THREAD, this_cp, cp_index, tag, PENDING_EXCEPTION);
1077 // CAS in the tag. If a thread beat us to registering this error that's fine.
1078 // If another thread resolved the reference, this is a race condition. This
1079 // thread may have had a security manager or something temporary.
1080 // This doesn't deterministically get an error. So why do we save this?
1081 // We save this because jvmti can add classes to the bootclass path after
1082 // this error, so it needs to get the same error if the error is first.
1083 jbyte old_tag = Atomic::cmpxchg((jbyte*)this_cp->tag_addr_at(cp_index),
1084 (jbyte)tag.value(),
1085 (jbyte)error_tag);
1086 if (old_tag != error_tag && old_tag != tag.value()) {
1087 // MethodHandles and MethodType doesn't change to resolved version.
1088 assert(this_cp->tag_at(cp_index).is_klass(), "Wrong tag value");
1089 // Forget the exception and use the resolved class.
1090 CLEAR_PENDING_EXCEPTION;
1091 }
1092 } else {
1093 // some other thread put this in error state
1094 throw_resolution_error(this_cp, cp_index, CHECK);
1095 }
1096 }
1097
1098 constantTag ConstantPool::constant_tag_at(int cp_index) {
1099 constantTag tag = tag_at(cp_index);
1100 if (tag.is_dynamic_constant()) {
1101 BasicType bt = basic_type_for_constant_at(cp_index);
1102 return constantTag(constantTag::type2tag(bt));
1103 }
1104 return tag;
1105 }
1106
1107 BasicType ConstantPool::basic_type_for_constant_at(int cp_index) {
1108 constantTag tag = tag_at(cp_index);
1109 if (tag.is_dynamic_constant() ||
1110 tag.is_dynamic_constant_in_error()) {
1111 // have to look at the signature for this one
1112 Symbol* constant_type = uncached_signature_ref_at(cp_index);
1113 return Signature::basic_type(constant_type);
1114 }
1115 return tag.basic_type();
1116 }
1117
1118 // Called to resolve constants in the constant pool and return an oop.
1119 // Some constant pool entries cache their resolved oop. This is also
1120 // called to create oops from constants to use in arguments for invokedynamic
1121 oop ConstantPool::resolve_constant_at_impl(const constantPoolHandle& this_cp,
1122 int cp_index, int cache_index,
1123 bool* status_return, TRAPS) {
1124 oop result_oop = nullptr;
1125
1126 if (cache_index == _possible_index_sentinel) {
1127 // It is possible that this constant is one which is cached in the objects.
1128 // We'll do a linear search. This should be OK because this usage is rare.
1129 // FIXME: If bootstrap specifiers stress this code, consider putting in
1130 // a reverse index. Binary search over a short array should do it.
1131 assert(cp_index > 0, "valid constant pool index");
1132 cache_index = this_cp->cp_to_object_index(cp_index);
1133 }
1134 assert(cache_index == _no_index_sentinel || cache_index >= 0, "");
1135 assert(cp_index == _no_index_sentinel || cp_index >= 0, "");
1136
1137 if (cache_index >= 0) {
1138 result_oop = this_cp->resolved_reference_at(cache_index);
1139 if (result_oop != nullptr) {
1140 if (result_oop == Universe::the_null_sentinel()) {
1141 DEBUG_ONLY(int temp_index = (cp_index >= 0 ? cp_index : this_cp->object_to_cp_index(cache_index)));
1142 assert(this_cp->tag_at(temp_index).is_dynamic_constant(), "only condy uses the null sentinel");
1143 result_oop = nullptr;
1144 }
1145 if (status_return != nullptr) (*status_return) = true;
1146 return result_oop;
1147 // That was easy...
1148 }
1149 cp_index = this_cp->object_to_cp_index(cache_index);
1150 }
1151
1152 jvalue prim_value; // temp used only in a few cases below
1153
1154 constantTag tag = this_cp->tag_at(cp_index);
1155
1156 if (status_return != nullptr) {
1157 // don't trigger resolution if the constant might need it
1158 switch (tag.value()) {
1159 case JVM_CONSTANT_Class:
1160 {
1161 CPKlassSlot kslot = this_cp->klass_slot_at(cp_index);
1162 int resolved_klass_index = kslot.resolved_klass_index();
1163 if (this_cp->resolved_klasses()->at(resolved_klass_index) == nullptr) {
1164 (*status_return) = false;
1165 return nullptr;
1166 }
1167 // the klass is waiting in the CP; go get it
1168 break;
1169 }
1170 case JVM_CONSTANT_String:
1171 case JVM_CONSTANT_Integer:
1172 case JVM_CONSTANT_Float:
1173 case JVM_CONSTANT_Long:
1174 case JVM_CONSTANT_Double:
1175 // these guys trigger OOM at worst
1176 break;
1177 default:
1178 (*status_return) = false;
1179 return nullptr;
1180 }
1181 // from now on there is either success or an OOME
1182 (*status_return) = true;
1183 }
1184
1185 switch (tag.value()) {
1186
1187 case JVM_CONSTANT_UnresolvedClass:
1188 case JVM_CONSTANT_Class:
1189 {
1190 assert(cache_index == _no_index_sentinel, "should not have been set");
1191 Klass* resolved = klass_at_impl(this_cp, cp_index, CHECK_NULL);
1192 // ldc wants the java mirror.
1193 result_oop = resolved->java_mirror();
1194 break;
1195 }
1196
1197 case JVM_CONSTANT_Dynamic:
1198 { PerfTraceTimedEvent timer(ClassLoader::perf_resolve_invokedynamic_time(),
1199 ClassLoader::perf_resolve_invokedynamic_count());
1200
1201 // Resolve the Dynamically-Computed constant to invoke the BSM in order to obtain the resulting oop.
1202 BootstrapInfo bootstrap_specifier(this_cp, cp_index);
1203
1204 // The initial step in resolving an unresolved symbolic reference to a
1205 // dynamically-computed constant is to resolve the symbolic reference to a
1206 // method handle which will be the bootstrap method for the dynamically-computed
1207 // constant. If resolution of the java.lang.invoke.MethodHandle for the bootstrap
1208 // method fails, then a MethodHandleInError is stored at the corresponding
1209 // bootstrap method's CP index for the CONSTANT_MethodHandle_info. No need to
1210 // set a DynamicConstantInError here since any subsequent use of this
1211 // bootstrap method will encounter the resolution of MethodHandleInError.
1212 // Both the first, (resolution of the BSM and its static arguments), and the second tasks,
1213 // (invocation of the BSM), of JVMS Section 5.4.3.6 occur within invoke_bootstrap_method()
1214 // for the bootstrap_specifier created above.
1215 SystemDictionary::invoke_bootstrap_method(bootstrap_specifier, THREAD);
1216 Exceptions::wrap_dynamic_exception(/* is_indy */ false, THREAD);
1217 if (HAS_PENDING_EXCEPTION) {
1218 // Resolution failure of the dynamically-computed constant, save_and_throw_exception
1219 // will check for a LinkageError and store a DynamicConstantInError.
1220 save_and_throw_exception(this_cp, cp_index, tag, CHECK_NULL);
1221 }
1222 result_oop = bootstrap_specifier.resolved_value()();
1223 BasicType type = Signature::basic_type(bootstrap_specifier.signature());
1224 if (!is_reference_type(type)) {
1225 // Make sure the primitive value is properly boxed.
1226 // This is a JDK responsibility.
1227 const char* fail = nullptr;
1228 if (result_oop == nullptr) {
1229 fail = "null result instead of box";
1230 } else if (!is_java_primitive(type)) {
1231 // FIXME: support value types via unboxing
1232 fail = "can only handle references and primitives";
1233 } else if (!java_lang_boxing_object::is_instance(result_oop, type)) {
1234 fail = "primitive is not properly boxed";
1235 }
1236 if (fail != nullptr) {
1237 // Since this exception is not a LinkageError, throw exception
1238 // but do not save a DynamicInError resolution result.
1239 // See section 5.4.3 of the VM spec.
1240 THROW_MSG_NULL(vmSymbols::java_lang_InternalError(), fail);
1241 }
1242 }
1243
1244 LogTarget(Debug, methodhandles, condy) lt_condy;
1245 if (lt_condy.is_enabled()) {
1246 LogStream ls(lt_condy);
1247 bootstrap_specifier.print_msg_on(&ls, "resolve_constant_at_impl");
1248 }
1249 break;
1250 }
1251
1252 case JVM_CONSTANT_String:
1253 assert(cache_index != _no_index_sentinel, "should have been set");
1254 result_oop = string_at_impl(this_cp, cp_index, cache_index, CHECK_NULL);
1255 break;
1256
1257 case JVM_CONSTANT_MethodHandle:
1258 { PerfTraceTimedEvent timer(ClassLoader::perf_resolve_method_handle_time(),
1259 ClassLoader::perf_resolve_method_handle_count());
1260
1261 int ref_kind = this_cp->method_handle_ref_kind_at(cp_index);
1262 int callee_index = this_cp->method_handle_klass_index_at(cp_index);
1263 Symbol* name = this_cp->method_handle_name_ref_at(cp_index);
1264 Symbol* signature = this_cp->method_handle_signature_ref_at(cp_index);
1265 constantTag m_tag = this_cp->tag_at(this_cp->method_handle_index_at(cp_index));
1266 { ResourceMark rm(THREAD);
1267 log_debug(class, resolve)("resolve JVM_CONSTANT_MethodHandle:%d [%d/%d/%d] %s.%s",
1268 ref_kind, cp_index, this_cp->method_handle_index_at(cp_index),
1269 callee_index, name->as_C_string(), signature->as_C_string());
1270 }
1271
1272 Klass* callee = klass_at_impl(this_cp, callee_index, THREAD);
1273 if (HAS_PENDING_EXCEPTION) {
1274 save_and_throw_exception(this_cp, cp_index, tag, CHECK_NULL);
1275 }
1276
1277 // Check constant pool method consistency
1278 if ((callee->is_interface() && m_tag.is_method()) ||
1279 (!callee->is_interface() && m_tag.is_interface_method())) {
1280 ResourceMark rm(THREAD);
1281 stringStream ss;
1282 ss.print("Inconsistent constant pool data in classfile for class %s. "
1283 "Method '", callee->name()->as_C_string());
1284 signature->print_as_signature_external_return_type(&ss);
1285 ss.print(" %s(", name->as_C_string());
1286 signature->print_as_signature_external_parameters(&ss);
1287 ss.print(")' at index %d is %s and should be %s",
1288 cp_index,
1289 callee->is_interface() ? "CONSTANT_MethodRef" : "CONSTANT_InterfaceMethodRef",
1290 callee->is_interface() ? "CONSTANT_InterfaceMethodRef" : "CONSTANT_MethodRef");
1291 // Names are all known to be < 64k so we know this formatted message is not excessively large.
1292 Exceptions::fthrow(THREAD_AND_LOCATION, vmSymbols::java_lang_IncompatibleClassChangeError(), "%s", ss.as_string());
1293 save_and_throw_exception(this_cp, cp_index, tag, CHECK_NULL);
1294 }
1295
1296 Klass* klass = this_cp->pool_holder();
1297 HandleMark hm(THREAD);
1298 Handle value = SystemDictionary::link_method_handle_constant(klass, ref_kind,
1299 callee, name, signature,
1300 THREAD);
1301 if (HAS_PENDING_EXCEPTION) {
1302 save_and_throw_exception(this_cp, cp_index, tag, CHECK_NULL);
1303 }
1304 result_oop = value();
1305 break;
1306 }
1307
1308 case JVM_CONSTANT_MethodType:
1309 { PerfTraceTimedEvent timer(ClassLoader::perf_resolve_method_type_time(),
1310 ClassLoader::perf_resolve_method_type_count());
1311
1312 Symbol* signature = this_cp->method_type_signature_at(cp_index);
1313 { ResourceMark rm(THREAD);
1314 log_debug(class, resolve)("resolve JVM_CONSTANT_MethodType [%d/%d] %s",
1315 cp_index, this_cp->method_type_index_at(cp_index),
1316 signature->as_C_string());
1317 }
1318 Klass* klass = this_cp->pool_holder();
1319 HandleMark hm(THREAD);
1320 Handle value = SystemDictionary::find_method_handle_type(signature, klass, THREAD);
1321 result_oop = value();
1322 if (HAS_PENDING_EXCEPTION) {
1323 save_and_throw_exception(this_cp, cp_index, tag, CHECK_NULL);
1324 }
1325 break;
1326 }
1327
1328 case JVM_CONSTANT_Integer:
1329 assert(cache_index == _no_index_sentinel, "should not have been set");
1330 prim_value.i = this_cp->int_at(cp_index);
1331 result_oop = java_lang_boxing_object::create(T_INT, &prim_value, CHECK_NULL);
1332 break;
1333
1334 case JVM_CONSTANT_Float:
1335 assert(cache_index == _no_index_sentinel, "should not have been set");
1336 prim_value.f = this_cp->float_at(cp_index);
1337 result_oop = java_lang_boxing_object::create(T_FLOAT, &prim_value, CHECK_NULL);
1338 break;
1339
1340 case JVM_CONSTANT_Long:
1341 assert(cache_index == _no_index_sentinel, "should not have been set");
1342 prim_value.j = this_cp->long_at(cp_index);
1343 result_oop = java_lang_boxing_object::create(T_LONG, &prim_value, CHECK_NULL);
1344 break;
1345
1346 case JVM_CONSTANT_Double:
1347 assert(cache_index == _no_index_sentinel, "should not have been set");
1348 prim_value.d = this_cp->double_at(cp_index);
1349 result_oop = java_lang_boxing_object::create(T_DOUBLE, &prim_value, CHECK_NULL);
1350 break;
1351
1352 case JVM_CONSTANT_UnresolvedClassInError:
1353 case JVM_CONSTANT_DynamicInError:
1354 case JVM_CONSTANT_MethodHandleInError:
1355 case JVM_CONSTANT_MethodTypeInError:
1356 throw_resolution_error(this_cp, cp_index, CHECK_NULL);
1357 break;
1358
1359 default:
1360 fatal("unexpected constant tag at CP %p[%d/%d] = %d", this_cp(), cp_index, cache_index, tag.value());
1361 break;
1362 }
1363
1364 if (cache_index >= 0) {
1365 // Benign race condition: resolved_references may already be filled in.
1366 // The important thing here is that all threads pick up the same result.
1367 // It doesn't matter which racing thread wins, as long as only one
1368 // result is used by all threads, and all future queries.
1369 oop new_result = (result_oop == nullptr ? Universe::the_null_sentinel() : result_oop);
1370 oop old_result = this_cp->set_resolved_reference_at(cache_index, new_result);
1371 if (old_result == nullptr) {
1372 return result_oop; // was installed
1373 } else {
1374 // Return the winning thread's result. This can be different than
1375 // the result here for MethodHandles.
1376 if (old_result == Universe::the_null_sentinel())
1377 old_result = nullptr;
1378 return old_result;
1379 }
1380 } else {
1381 assert(result_oop != Universe::the_null_sentinel(), "");
1382 return result_oop;
1383 }
1384 }
1385
1386 oop ConstantPool::uncached_string_at(int cp_index, TRAPS) {
1387 Symbol* sym = unresolved_string_at(cp_index);
1388 oop str = StringTable::intern(sym, CHECK_(nullptr));
1389 assert(java_lang_String::is_instance(str), "must be string");
1390 return str;
1391 }
1392
1393 void ConstantPool::copy_bootstrap_arguments_at_impl(const constantPoolHandle& this_cp, int cp_index,
1394 int start_arg, int end_arg,
1395 objArrayHandle info, int pos,
1396 bool must_resolve, Handle if_not_available,
1397 TRAPS) {
1398 int limit = pos + end_arg - start_arg;
1399 // checks: cp_index in range [0..this_cp->length),
1400 // tag at cp_index, start..end in range [0..this_cp->bootstrap_argument_count],
1401 // info array non-null, pos..limit in [0..info.length]
1402 if ((0 >= cp_index || cp_index >= this_cp->length()) ||
1403 !(this_cp->tag_at(cp_index).is_invoke_dynamic() ||
1404 this_cp->tag_at(cp_index).is_dynamic_constant()) ||
1405 (0 > start_arg || start_arg > end_arg) ||
1406 (end_arg > this_cp->bootstrap_argument_count_at(cp_index)) ||
1407 (0 > pos || pos > limit) ||
1408 (info.is_null() || limit > info->length())) {
1409 // An index or something else went wrong; throw an error.
1410 // Since this is an internal API, we don't expect this,
1411 // so we don't bother to craft a nice message.
1412 THROW_MSG(vmSymbols::java_lang_LinkageError(), "bad BSM argument access");
1413 }
1414 // now we can loop safely
1415 int info_i = pos;
1416 for (int i = start_arg; i < end_arg; i++) {
1417 int arg_index = this_cp->bootstrap_argument_index_at(cp_index, i);
1418 oop arg_oop;
1419 if (must_resolve) {
1420 arg_oop = this_cp->resolve_possibly_cached_constant_at(arg_index, CHECK);
1421 } else {
1422 bool found_it = false;
1423 arg_oop = this_cp->find_cached_constant_at(arg_index, found_it, CHECK);
1424 if (!found_it) arg_oop = if_not_available();
1425 }
1426 info->obj_at_put(info_i++, arg_oop);
1427 }
1428 }
1429
1430 oop ConstantPool::string_at_impl(const constantPoolHandle& this_cp, int cp_index, int obj_index, TRAPS) {
1431 // If the string has already been interned, this entry will be non-null
1432 oop str = this_cp->resolved_reference_at(obj_index);
1433 assert(str != Universe::the_null_sentinel(), "");
1434 if (str != nullptr) return str;
1435 Symbol* sym = this_cp->unresolved_string_at(cp_index);
1436 str = StringTable::intern(sym, CHECK_(nullptr));
1437 this_cp->string_at_put(obj_index, str);
1438 assert(java_lang_String::is_instance(str), "must be string");
1439 return str;
1440 }
1441
1442
1443 bool ConstantPool::klass_name_at_matches(const InstanceKlass* k, int cp_index) {
1444 // Names are interned, so we can compare Symbol*s directly
1445 Symbol* cp_name = klass_name_at(cp_index);
1446 return (cp_name == k->name());
1447 }
1448
1449
1450 // Iterate over symbols and decrement ones which are Symbol*s
1451 // This is done during GC.
1452 // Only decrement the UTF8 symbols. Strings point to
1453 // these symbols but didn't increment the reference count.
1454 void ConstantPool::unreference_symbols() {
1455 for (int index = 1; index < length(); index++) { // Index 0 is unused
1456 constantTag tag = tag_at(index);
1457 if (tag.is_symbol()) {
1458 symbol_at(index)->decrement_refcount();
1459 }
1460 }
1461 }
1462
1463
1464 // Compare this constant pool's entry at index1 to the constant pool
1465 // cp2's entry at index2.
1466 bool ConstantPool::compare_entry_to(int index1, const constantPoolHandle& cp2,
1467 int index2) {
1468
1469 // The error tags are equivalent to non-error tags when comparing
1470 jbyte t1 = tag_at(index1).non_error_value();
1471 jbyte t2 = cp2->tag_at(index2).non_error_value();
1472
1473 // Some classes are pre-resolved (like Throwable) which may lead to
1474 // consider it as a different entry. We then revert them back temporarily
1475 // to ensure proper comparison.
1476 if (t1 == JVM_CONSTANT_Class) {
1477 t1 = JVM_CONSTANT_UnresolvedClass;
1478 }
1479 if (t2 == JVM_CONSTANT_Class) {
1480 t2 = JVM_CONSTANT_UnresolvedClass;
1481 }
1482
1483 if (t1 != t2) {
1484 // Not the same entry type so there is nothing else to check. Note
1485 // that this style of checking will consider resolved/unresolved
1486 // class pairs as different.
1487 // From the ConstantPool* API point of view, this is correct
1488 // behavior. See VM_RedefineClasses::merge_constant_pools() to see how this
1489 // plays out in the context of ConstantPool* merging.
1490 return false;
1491 }
1492
1493 switch (t1) {
1494 case JVM_CONSTANT_ClassIndex:
1495 {
1496 int recur1 = klass_index_at(index1);
1497 int recur2 = cp2->klass_index_at(index2);
1498 if (compare_entry_to(recur1, cp2, recur2)) {
1499 return true;
1500 }
1501 } break;
1502
1503 case JVM_CONSTANT_Double:
1504 {
1505 jdouble d1 = double_at(index1);
1506 jdouble d2 = cp2->double_at(index2);
1507 if (d1 == d2) {
1508 return true;
1509 }
1510 } break;
1511
1512 case JVM_CONSTANT_Fieldref:
1513 case JVM_CONSTANT_InterfaceMethodref:
1514 case JVM_CONSTANT_Methodref:
1515 {
1516 int recur1 = uncached_klass_ref_index_at(index1);
1517 int recur2 = cp2->uncached_klass_ref_index_at(index2);
1518 bool match = compare_entry_to(recur1, cp2, recur2);
1519 if (match) {
1520 recur1 = uncached_name_and_type_ref_index_at(index1);
1521 recur2 = cp2->uncached_name_and_type_ref_index_at(index2);
1522 if (compare_entry_to(recur1, cp2, recur2)) {
1523 return true;
1524 }
1525 }
1526 } break;
1527
1528 case JVM_CONSTANT_Float:
1529 {
1530 jfloat f1 = float_at(index1);
1531 jfloat f2 = cp2->float_at(index2);
1532 if (f1 == f2) {
1533 return true;
1534 }
1535 } break;
1536
1537 case JVM_CONSTANT_Integer:
1538 {
1539 jint i1 = int_at(index1);
1540 jint i2 = cp2->int_at(index2);
1541 if (i1 == i2) {
1542 return true;
1543 }
1544 } break;
1545
1546 case JVM_CONSTANT_Long:
1547 {
1548 jlong l1 = long_at(index1);
1549 jlong l2 = cp2->long_at(index2);
1550 if (l1 == l2) {
1551 return true;
1552 }
1553 } break;
1554
1555 case JVM_CONSTANT_NameAndType:
1556 {
1557 int recur1 = name_ref_index_at(index1);
1558 int recur2 = cp2->name_ref_index_at(index2);
1559 if (compare_entry_to(recur1, cp2, recur2)) {
1560 recur1 = signature_ref_index_at(index1);
1561 recur2 = cp2->signature_ref_index_at(index2);
1562 if (compare_entry_to(recur1, cp2, recur2)) {
1563 return true;
1564 }
1565 }
1566 } break;
1567
1568 case JVM_CONSTANT_StringIndex:
1569 {
1570 int recur1 = string_index_at(index1);
1571 int recur2 = cp2->string_index_at(index2);
1572 if (compare_entry_to(recur1, cp2, recur2)) {
1573 return true;
1574 }
1575 } break;
1576
1577 case JVM_CONSTANT_UnresolvedClass:
1578 {
1579 Symbol* k1 = klass_name_at(index1);
1580 Symbol* k2 = cp2->klass_name_at(index2);
1581 if (k1 == k2) {
1582 return true;
1583 }
1584 } break;
1585
1586 case JVM_CONSTANT_MethodType:
1587 {
1588 int k1 = method_type_index_at(index1);
1589 int k2 = cp2->method_type_index_at(index2);
1590 if (compare_entry_to(k1, cp2, k2)) {
1591 return true;
1592 }
1593 } break;
1594
1595 case JVM_CONSTANT_MethodHandle:
1596 {
1597 int k1 = method_handle_ref_kind_at(index1);
1598 int k2 = cp2->method_handle_ref_kind_at(index2);
1599 if (k1 == k2) {
1600 int i1 = method_handle_index_at(index1);
1601 int i2 = cp2->method_handle_index_at(index2);
1602 if (compare_entry_to(i1, cp2, i2)) {
1603 return true;
1604 }
1605 }
1606 } break;
1607
1608 case JVM_CONSTANT_Dynamic:
1609 {
1610 int k1 = bootstrap_name_and_type_ref_index_at(index1);
1611 int k2 = cp2->bootstrap_name_and_type_ref_index_at(index2);
1612 int i1 = bootstrap_methods_attribute_index(index1);
1613 int i2 = cp2->bootstrap_methods_attribute_index(index2);
1614 bool match_entry = compare_entry_to(k1, cp2, k2);
1615 bool match_operand = compare_operand_to(i1, cp2, i2);
1616 return (match_entry && match_operand);
1617 } break;
1618
1619 case JVM_CONSTANT_InvokeDynamic:
1620 {
1621 int k1 = bootstrap_name_and_type_ref_index_at(index1);
1622 int k2 = cp2->bootstrap_name_and_type_ref_index_at(index2);
1623 int i1 = bootstrap_methods_attribute_index(index1);
1624 int i2 = cp2->bootstrap_methods_attribute_index(index2);
1625 bool match_entry = compare_entry_to(k1, cp2, k2);
1626 bool match_operand = compare_operand_to(i1, cp2, i2);
1627 return (match_entry && match_operand);
1628 } break;
1629
1630 case JVM_CONSTANT_String:
1631 {
1632 Symbol* s1 = unresolved_string_at(index1);
1633 Symbol* s2 = cp2->unresolved_string_at(index2);
1634 if (s1 == s2) {
1635 return true;
1636 }
1637 } break;
1638
1639 case JVM_CONSTANT_Utf8:
1640 {
1641 Symbol* s1 = symbol_at(index1);
1642 Symbol* s2 = cp2->symbol_at(index2);
1643 if (s1 == s2) {
1644 return true;
1645 }
1646 } break;
1647
1648 // Invalid is used as the tag for the second constant pool entry
1649 // occupied by JVM_CONSTANT_Double or JVM_CONSTANT_Long. It should
1650 // not be seen by itself.
1651 case JVM_CONSTANT_Invalid: // fall through
1652
1653 default:
1654 ShouldNotReachHere();
1655 break;
1656 }
1657
1658 return false;
1659 } // end compare_entry_to()
1660
1661
1662 // Resize the operands array with delta_len and delta_size.
1663 // Used in RedefineClasses for CP merge.
1664 void ConstantPool::resize_operands(int delta_len, int delta_size, TRAPS) {
1665 int old_len = operand_array_length(operands());
1666 int new_len = old_len + delta_len;
1667 int min_len = (delta_len > 0) ? old_len : new_len;
1668
1669 int old_size = operands()->length();
1670 int new_size = old_size + delta_size;
1671 int min_size = (delta_size > 0) ? old_size : new_size;
1672
1673 ClassLoaderData* loader_data = pool_holder()->class_loader_data();
1674 Array<u2>* new_ops = MetadataFactory::new_array<u2>(loader_data, new_size, CHECK);
1675
1676 // Set index in the resized array for existing elements only
1677 for (int idx = 0; idx < min_len; idx++) {
1678 int offset = operand_offset_at(idx); // offset in original array
1679 operand_offset_at_put(new_ops, idx, offset + 2*delta_len); // offset in resized array
1680 }
1681 // Copy the bootstrap specifiers only
1682 Copy::conjoint_memory_atomic(operands()->adr_at(2*old_len),
1683 new_ops->adr_at(2*new_len),
1684 (min_size - 2*min_len) * sizeof(u2));
1685 // Explicitly deallocate old operands array.
1686 // Note, it is not needed for 7u backport.
1687 if ( operands() != nullptr) { // the safety check
1688 MetadataFactory::free_array<u2>(loader_data, operands());
1689 }
1690 set_operands(new_ops);
1691 } // end resize_operands()
1692
1693
1694 // Extend the operands array with the length and size of the ext_cp operands.
1695 // Used in RedefineClasses for CP merge.
1696 void ConstantPool::extend_operands(const constantPoolHandle& ext_cp, TRAPS) {
1697 int delta_len = operand_array_length(ext_cp->operands());
1698 if (delta_len == 0) {
1699 return; // nothing to do
1700 }
1701 int delta_size = ext_cp->operands()->length();
1702
1703 assert(delta_len > 0 && delta_size > 0, "extended operands array must be bigger");
1704
1705 if (operand_array_length(operands()) == 0) {
1706 ClassLoaderData* loader_data = pool_holder()->class_loader_data();
1707 Array<u2>* new_ops = MetadataFactory::new_array<u2>(loader_data, delta_size, CHECK);
1708 // The first element index defines the offset of second part
1709 operand_offset_at_put(new_ops, 0, 2*delta_len); // offset in new array
1710 set_operands(new_ops);
1711 } else {
1712 resize_operands(delta_len, delta_size, CHECK);
1713 }
1714
1715 } // end extend_operands()
1716
1717
1718 // Shrink the operands array to a smaller array with new_len length.
1719 // Used in RedefineClasses for CP merge.
1720 void ConstantPool::shrink_operands(int new_len, TRAPS) {
1721 int old_len = operand_array_length(operands());
1722 if (new_len == old_len) {
1723 return; // nothing to do
1724 }
1725 assert(new_len < old_len, "shrunken operands array must be smaller");
1726
1727 int free_base = operand_next_offset_at(new_len - 1);
1728 int delta_len = new_len - old_len;
1729 int delta_size = 2*delta_len + free_base - operands()->length();
1730
1731 resize_operands(delta_len, delta_size, CHECK);
1732
1733 } // end shrink_operands()
1734
1735
1736 void ConstantPool::copy_operands(const constantPoolHandle& from_cp,
1737 const constantPoolHandle& to_cp,
1738 TRAPS) {
1739
1740 int from_oplen = operand_array_length(from_cp->operands());
1741 int old_oplen = operand_array_length(to_cp->operands());
1742 if (from_oplen != 0) {
1743 ClassLoaderData* loader_data = to_cp->pool_holder()->class_loader_data();
1744 // append my operands to the target's operands array
1745 if (old_oplen == 0) {
1746 // Can't just reuse from_cp's operand list because of deallocation issues
1747 int len = from_cp->operands()->length();
1748 Array<u2>* new_ops = MetadataFactory::new_array<u2>(loader_data, len, CHECK);
1749 Copy::conjoint_memory_atomic(
1750 from_cp->operands()->adr_at(0), new_ops->adr_at(0), len * sizeof(u2));
1751 to_cp->set_operands(new_ops);
1752 } else {
1753 int old_len = to_cp->operands()->length();
1754 int from_len = from_cp->operands()->length();
1755 int old_off = old_oplen * sizeof(u2);
1756 int from_off = from_oplen * sizeof(u2);
1757 // Use the metaspace for the destination constant pool
1758 Array<u2>* new_operands = MetadataFactory::new_array<u2>(loader_data, old_len + from_len, CHECK);
1759 int fillp = 0, len = 0;
1760 // first part of dest
1761 Copy::conjoint_memory_atomic(to_cp->operands()->adr_at(0),
1762 new_operands->adr_at(fillp),
1763 (len = old_off) * sizeof(u2));
1764 fillp += len;
1765 // first part of src
1766 Copy::conjoint_memory_atomic(from_cp->operands()->adr_at(0),
1767 new_operands->adr_at(fillp),
1768 (len = from_off) * sizeof(u2));
1769 fillp += len;
1770 // second part of dest
1771 Copy::conjoint_memory_atomic(to_cp->operands()->adr_at(old_off),
1772 new_operands->adr_at(fillp),
1773 (len = old_len - old_off) * sizeof(u2));
1774 fillp += len;
1775 // second part of src
1776 Copy::conjoint_memory_atomic(from_cp->operands()->adr_at(from_off),
1777 new_operands->adr_at(fillp),
1778 (len = from_len - from_off) * sizeof(u2));
1779 fillp += len;
1780 assert(fillp == new_operands->length(), "");
1781
1782 // Adjust indexes in the first part of the copied operands array.
1783 for (int j = 0; j < from_oplen; j++) {
1784 int offset = operand_offset_at(new_operands, old_oplen + j);
1785 assert(offset == operand_offset_at(from_cp->operands(), j), "correct copy");
1786 offset += old_len; // every new tuple is preceded by old_len extra u2's
1787 operand_offset_at_put(new_operands, old_oplen + j, offset);
1788 }
1789
1790 // replace target operands array with combined array
1791 to_cp->set_operands(new_operands);
1792 }
1793 }
1794 } // end copy_operands()
1795
1796
1797 // Copy this constant pool's entries at start_i to end_i (inclusive)
1798 // to the constant pool to_cp's entries starting at to_i. A total of
1799 // (end_i - start_i) + 1 entries are copied.
1800 void ConstantPool::copy_cp_to_impl(const constantPoolHandle& from_cp, int start_i, int end_i,
1801 const constantPoolHandle& to_cp, int to_i, TRAPS) {
1802
1803
1804 int dest_cpi = to_i; // leave original alone for debug purposes
1805
1806 for (int src_cpi = start_i; src_cpi <= end_i; /* see loop bottom */ ) {
1807 copy_entry_to(from_cp, src_cpi, to_cp, dest_cpi);
1808
1809 switch (from_cp->tag_at(src_cpi).value()) {
1810 case JVM_CONSTANT_Double:
1811 case JVM_CONSTANT_Long:
1812 // double and long take two constant pool entries
1813 src_cpi += 2;
1814 dest_cpi += 2;
1815 break;
1816
1817 default:
1818 // all others take one constant pool entry
1819 src_cpi++;
1820 dest_cpi++;
1821 break;
1822 }
1823 }
1824 copy_operands(from_cp, to_cp, CHECK);
1825
1826 } // end copy_cp_to_impl()
1827
1828
1829 // Copy this constant pool's entry at from_i to the constant pool
1830 // to_cp's entry at to_i.
1831 void ConstantPool::copy_entry_to(const constantPoolHandle& from_cp, int from_i,
1832 const constantPoolHandle& to_cp, int to_i) {
1833
1834 int tag = from_cp->tag_at(from_i).value();
1835 switch (tag) {
1836 case JVM_CONSTANT_ClassIndex:
1837 {
1838 jint ki = from_cp->klass_index_at(from_i);
1839 to_cp->klass_index_at_put(to_i, ki);
1840 } break;
1841
1842 case JVM_CONSTANT_Double:
1843 {
1844 jdouble d = from_cp->double_at(from_i);
1845 to_cp->double_at_put(to_i, d);
1846 // double takes two constant pool entries so init second entry's tag
1847 to_cp->tag_at_put(to_i + 1, JVM_CONSTANT_Invalid);
1848 } break;
1849
1850 case JVM_CONSTANT_Fieldref:
1851 {
1852 int class_index = from_cp->uncached_klass_ref_index_at(from_i);
1853 int name_and_type_index = from_cp->uncached_name_and_type_ref_index_at(from_i);
1854 to_cp->field_at_put(to_i, class_index, name_and_type_index);
1855 } break;
1856
1857 case JVM_CONSTANT_Float:
1858 {
1859 jfloat f = from_cp->float_at(from_i);
1860 to_cp->float_at_put(to_i, f);
1861 } break;
1862
1863 case JVM_CONSTANT_Integer:
1864 {
1865 jint i = from_cp->int_at(from_i);
1866 to_cp->int_at_put(to_i, i);
1867 } break;
1868
1869 case JVM_CONSTANT_InterfaceMethodref:
1870 {
1871 int class_index = from_cp->uncached_klass_ref_index_at(from_i);
1872 int name_and_type_index = from_cp->uncached_name_and_type_ref_index_at(from_i);
1873 to_cp->interface_method_at_put(to_i, class_index, name_and_type_index);
1874 } break;
1875
1876 case JVM_CONSTANT_Long:
1877 {
1878 jlong l = from_cp->long_at(from_i);
1879 to_cp->long_at_put(to_i, l);
1880 // long takes two constant pool entries so init second entry's tag
1881 to_cp->tag_at_put(to_i + 1, JVM_CONSTANT_Invalid);
1882 } break;
1883
1884 case JVM_CONSTANT_Methodref:
1885 {
1886 int class_index = from_cp->uncached_klass_ref_index_at(from_i);
1887 int name_and_type_index = from_cp->uncached_name_and_type_ref_index_at(from_i);
1888 to_cp->method_at_put(to_i, class_index, name_and_type_index);
1889 } break;
1890
1891 case JVM_CONSTANT_NameAndType:
1892 {
1893 int name_ref_index = from_cp->name_ref_index_at(from_i);
1894 int signature_ref_index = from_cp->signature_ref_index_at(from_i);
1895 to_cp->name_and_type_at_put(to_i, name_ref_index, signature_ref_index);
1896 } break;
1897
1898 case JVM_CONSTANT_StringIndex:
1899 {
1900 jint si = from_cp->string_index_at(from_i);
1901 to_cp->string_index_at_put(to_i, si);
1902 } break;
1903
1904 case JVM_CONSTANT_Class:
1905 case JVM_CONSTANT_UnresolvedClass:
1906 case JVM_CONSTANT_UnresolvedClassInError:
1907 {
1908 // Revert to JVM_CONSTANT_ClassIndex
1909 int name_index = from_cp->klass_slot_at(from_i).name_index();
1910 assert(from_cp->tag_at(name_index).is_symbol(), "sanity");
1911 to_cp->klass_index_at_put(to_i, name_index);
1912 } break;
1913
1914 case JVM_CONSTANT_String:
1915 {
1916 Symbol* s = from_cp->unresolved_string_at(from_i);
1917 to_cp->unresolved_string_at_put(to_i, s);
1918 } break;
1919
1920 case JVM_CONSTANT_Utf8:
1921 {
1922 Symbol* s = from_cp->symbol_at(from_i);
1923 // Need to increase refcount, the old one will be thrown away and deferenced
1924 s->increment_refcount();
1925 to_cp->symbol_at_put(to_i, s);
1926 } break;
1927
1928 case JVM_CONSTANT_MethodType:
1929 case JVM_CONSTANT_MethodTypeInError:
1930 {
1931 jint k = from_cp->method_type_index_at(from_i);
1932 to_cp->method_type_index_at_put(to_i, k);
1933 } break;
1934
1935 case JVM_CONSTANT_MethodHandle:
1936 case JVM_CONSTANT_MethodHandleInError:
1937 {
1938 int k1 = from_cp->method_handle_ref_kind_at(from_i);
1939 int k2 = from_cp->method_handle_index_at(from_i);
1940 to_cp->method_handle_index_at_put(to_i, k1, k2);
1941 } break;
1942
1943 case JVM_CONSTANT_Dynamic:
1944 case JVM_CONSTANT_DynamicInError:
1945 {
1946 int k1 = from_cp->bootstrap_methods_attribute_index(from_i);
1947 int k2 = from_cp->bootstrap_name_and_type_ref_index_at(from_i);
1948 k1 += operand_array_length(to_cp->operands()); // to_cp might already have operands
1949 to_cp->dynamic_constant_at_put(to_i, k1, k2);
1950 } break;
1951
1952 case JVM_CONSTANT_InvokeDynamic:
1953 {
1954 int k1 = from_cp->bootstrap_methods_attribute_index(from_i);
1955 int k2 = from_cp->bootstrap_name_and_type_ref_index_at(from_i);
1956 k1 += operand_array_length(to_cp->operands()); // to_cp might already have operands
1957 to_cp->invoke_dynamic_at_put(to_i, k1, k2);
1958 } break;
1959
1960 // Invalid is used as the tag for the second constant pool entry
1961 // occupied by JVM_CONSTANT_Double or JVM_CONSTANT_Long. It should
1962 // not be seen by itself.
1963 case JVM_CONSTANT_Invalid: // fall through
1964
1965 default:
1966 {
1967 ShouldNotReachHere();
1968 } break;
1969 }
1970 } // end copy_entry_to()
1971
1972 // Search constant pool search_cp for an entry that matches this
1973 // constant pool's entry at pattern_i. Returns the index of a
1974 // matching entry or zero (0) if there is no matching entry.
1975 int ConstantPool::find_matching_entry(int pattern_i,
1976 const constantPoolHandle& search_cp) {
1977
1978 // index zero (0) is not used
1979 for (int i = 1; i < search_cp->length(); i++) {
1980 bool found = compare_entry_to(pattern_i, search_cp, i);
1981 if (found) {
1982 return i;
1983 }
1984 }
1985
1986 return 0; // entry not found; return unused index zero (0)
1987 } // end find_matching_entry()
1988
1989
1990 // Compare this constant pool's bootstrap specifier at idx1 to the constant pool
1991 // cp2's bootstrap specifier at idx2.
1992 bool ConstantPool::compare_operand_to(int idx1, const constantPoolHandle& cp2, int idx2) {
1993 int k1 = operand_bootstrap_method_ref_index_at(idx1);
1994 int k2 = cp2->operand_bootstrap_method_ref_index_at(idx2);
1995 bool match = compare_entry_to(k1, cp2, k2);
1996
1997 if (!match) {
1998 return false;
1999 }
2000 int argc = operand_argument_count_at(idx1);
2001 if (argc == cp2->operand_argument_count_at(idx2)) {
2002 for (int j = 0; j < argc; j++) {
2003 k1 = operand_argument_index_at(idx1, j);
2004 k2 = cp2->operand_argument_index_at(idx2, j);
2005 match = compare_entry_to(k1, cp2, k2);
2006 if (!match) {
2007 return false;
2008 }
2009 }
2010 return true; // got through loop; all elements equal
2011 }
2012 return false;
2013 } // end compare_operand_to()
2014
2015 // Search constant pool search_cp for a bootstrap specifier that matches
2016 // this constant pool's bootstrap specifier data at pattern_i index.
2017 // Return the index of a matching bootstrap attribute record or (-1) if there is no match.
2018 int ConstantPool::find_matching_operand(int pattern_i,
2019 const constantPoolHandle& search_cp, int search_len) {
2020 for (int i = 0; i < search_len; i++) {
2021 bool found = compare_operand_to(pattern_i, search_cp, i);
2022 if (found) {
2023 return i;
2024 }
2025 }
2026 return -1; // bootstrap specifier data not found; return unused index (-1)
2027 } // end find_matching_operand()
2028
2029
2030 #ifndef PRODUCT
2031
2032 const char* ConstantPool::printable_name_at(int cp_index) {
2033
2034 constantTag tag = tag_at(cp_index);
2035
2036 if (tag.is_string()) {
2037 return string_at_noresolve(cp_index);
2038 } else if (tag.is_klass() || tag.is_unresolved_klass()) {
2039 return klass_name_at(cp_index)->as_C_string();
2040 } else if (tag.is_symbol()) {
2041 return symbol_at(cp_index)->as_C_string();
2042 }
2043 return "";
2044 }
2045
2046 #endif // PRODUCT
2047
2048
2049 // JVMTI GetConstantPool support
2050
2051 // For debugging of constant pool
2052 const bool debug_cpool = false;
2053
2054 #define DBG(code) do { if (debug_cpool) { (code); } } while(0)
2055
2056 static void print_cpool_bytes(jint cnt, u1 *bytes) {
2057 const char* WARN_MSG = "Must not be such entry!";
2058 jint size = 0;
2059 u2 idx1, idx2;
2060
2061 for (jint idx = 1; idx < cnt; idx++) {
2062 jint ent_size = 0;
2063 u1 tag = *bytes++;
2064 size++; // count tag
2065
2066 printf("const #%03d, tag: %02d ", idx, tag);
2067 switch(tag) {
2068 case JVM_CONSTANT_Invalid: {
2069 printf("Invalid");
2070 break;
2071 }
2072 case JVM_CONSTANT_Unicode: {
2073 printf("Unicode %s", WARN_MSG);
2074 break;
2075 }
2076 case JVM_CONSTANT_Utf8: {
2077 u2 len = Bytes::get_Java_u2(bytes);
2078 char str[128];
2079 if (len > 127) {
2080 len = 127;
2081 }
2082 strncpy(str, (char *) (bytes+2), len);
2083 str[len] = '\0';
2084 printf("Utf8 \"%s\"", str);
2085 ent_size = 2 + len;
2086 break;
2087 }
2088 case JVM_CONSTANT_Integer: {
2089 u4 val = Bytes::get_Java_u4(bytes);
2090 printf("int %d", *(int *) &val);
2091 ent_size = 4;
2092 break;
2093 }
2094 case JVM_CONSTANT_Float: {
2095 u4 val = Bytes::get_Java_u4(bytes);
2096 printf("float %5.3ff", *(float *) &val);
2097 ent_size = 4;
2098 break;
2099 }
2100 case JVM_CONSTANT_Long: {
2101 u8 val = Bytes::get_Java_u8(bytes);
2102 printf("long " INT64_FORMAT, (int64_t) *(jlong *) &val);
2103 ent_size = 8;
2104 idx++; // Long takes two cpool slots
2105 break;
2106 }
2107 case JVM_CONSTANT_Double: {
2108 u8 val = Bytes::get_Java_u8(bytes);
2109 printf("double %5.3fd", *(jdouble *)&val);
2110 ent_size = 8;
2111 idx++; // Double takes two cpool slots
2112 break;
2113 }
2114 case JVM_CONSTANT_Class: {
2115 idx1 = Bytes::get_Java_u2(bytes);
2116 printf("class #%03d", idx1);
2117 ent_size = 2;
2118 break;
2119 }
2120 case JVM_CONSTANT_String: {
2121 idx1 = Bytes::get_Java_u2(bytes);
2122 printf("String #%03d", idx1);
2123 ent_size = 2;
2124 break;
2125 }
2126 case JVM_CONSTANT_Fieldref: {
2127 idx1 = Bytes::get_Java_u2(bytes);
2128 idx2 = Bytes::get_Java_u2(bytes+2);
2129 printf("Field #%03d, #%03d", (int) idx1, (int) idx2);
2130 ent_size = 4;
2131 break;
2132 }
2133 case JVM_CONSTANT_Methodref: {
2134 idx1 = Bytes::get_Java_u2(bytes);
2135 idx2 = Bytes::get_Java_u2(bytes+2);
2136 printf("Method #%03d, #%03d", idx1, idx2);
2137 ent_size = 4;
2138 break;
2139 }
2140 case JVM_CONSTANT_InterfaceMethodref: {
2141 idx1 = Bytes::get_Java_u2(bytes);
2142 idx2 = Bytes::get_Java_u2(bytes+2);
2143 printf("InterfMethod #%03d, #%03d", idx1, idx2);
2144 ent_size = 4;
2145 break;
2146 }
2147 case JVM_CONSTANT_NameAndType: {
2148 idx1 = Bytes::get_Java_u2(bytes);
2149 idx2 = Bytes::get_Java_u2(bytes+2);
2150 printf("NameAndType #%03d, #%03d", idx1, idx2);
2151 ent_size = 4;
2152 break;
2153 }
2154 case JVM_CONSTANT_ClassIndex: {
2155 printf("ClassIndex %s", WARN_MSG);
2156 break;
2157 }
2158 case JVM_CONSTANT_UnresolvedClass: {
2159 printf("UnresolvedClass: %s", WARN_MSG);
2160 break;
2161 }
2162 case JVM_CONSTANT_UnresolvedClassInError: {
2163 printf("UnresolvedClassInErr: %s", WARN_MSG);
2164 break;
2165 }
2166 case JVM_CONSTANT_StringIndex: {
2167 printf("StringIndex: %s", WARN_MSG);
2168 break;
2169 }
2170 }
2171 printf(";\n");
2172 bytes += ent_size;
2173 size += ent_size;
2174 }
2175 printf("Cpool size: %d\n", size);
2176 fflush(nullptr);
2177 return;
2178 } /* end print_cpool_bytes */
2179
2180
2181 // Returns size of constant pool entry.
2182 jint ConstantPool::cpool_entry_size(jint idx) {
2183 switch(tag_at(idx).value()) {
2184 case JVM_CONSTANT_Invalid:
2185 case JVM_CONSTANT_Unicode:
2186 return 1;
2187
2188 case JVM_CONSTANT_Utf8:
2189 return 3 + symbol_at(idx)->utf8_length();
2190
2191 case JVM_CONSTANT_Class:
2192 case JVM_CONSTANT_String:
2193 case JVM_CONSTANT_ClassIndex:
2194 case JVM_CONSTANT_UnresolvedClass:
2195 case JVM_CONSTANT_UnresolvedClassInError:
2196 case JVM_CONSTANT_StringIndex:
2197 case JVM_CONSTANT_MethodType:
2198 case JVM_CONSTANT_MethodTypeInError:
2199 return 3;
2200
2201 case JVM_CONSTANT_MethodHandle:
2202 case JVM_CONSTANT_MethodHandleInError:
2203 return 4; //tag, ref_kind, ref_index
2204
2205 case JVM_CONSTANT_Integer:
2206 case JVM_CONSTANT_Float:
2207 case JVM_CONSTANT_Fieldref:
2208 case JVM_CONSTANT_Methodref:
2209 case JVM_CONSTANT_InterfaceMethodref:
2210 case JVM_CONSTANT_NameAndType:
2211 return 5;
2212
2213 case JVM_CONSTANT_Dynamic:
2214 case JVM_CONSTANT_DynamicInError:
2215 case JVM_CONSTANT_InvokeDynamic:
2216 // u1 tag, u2 bsm, u2 nt
2217 return 5;
2218
2219 case JVM_CONSTANT_Long:
2220 case JVM_CONSTANT_Double:
2221 return 9;
2222 }
2223 assert(false, "cpool_entry_size: Invalid constant pool entry tag");
2224 return 1;
2225 } /* end cpool_entry_size */
2226
2227
2228 // SymbolHash is used to find a constant pool index from a string.
2229 // This function fills in SymbolHashs, one for utf8s and one for
2230 // class names, returns size of the cpool raw bytes.
2231 jint ConstantPool::hash_entries_to(SymbolHash *symmap,
2232 SymbolHash *classmap) {
2233 jint size = 0;
2234
2235 for (u2 idx = 1; idx < length(); idx++) {
2236 u2 tag = tag_at(idx).value();
2237 size += cpool_entry_size(idx);
2238
2239 switch(tag) {
2240 case JVM_CONSTANT_Utf8: {
2241 Symbol* sym = symbol_at(idx);
2242 symmap->add_if_absent(sym, idx);
2243 DBG(printf("adding symbol entry %s = %d\n", sym->as_utf8(), idx));
2244 break;
2245 }
2246 case JVM_CONSTANT_Class:
2247 case JVM_CONSTANT_UnresolvedClass:
2248 case JVM_CONSTANT_UnresolvedClassInError: {
2249 Symbol* sym = klass_name_at(idx);
2250 classmap->add_if_absent(sym, idx);
2251 DBG(printf("adding class entry %s = %d\n", sym->as_utf8(), idx));
2252 break;
2253 }
2254 case JVM_CONSTANT_Long:
2255 case JVM_CONSTANT_Double: {
2256 idx++; // Both Long and Double take two cpool slots
2257 break;
2258 }
2259 }
2260 }
2261 return size;
2262 } /* end hash_utf8_entries_to */
2263
2264
2265 // Copy cpool bytes.
2266 // Returns:
2267 // 0, in case of OutOfMemoryError
2268 // -1, in case of internal error
2269 // > 0, count of the raw cpool bytes that have been copied
2270 int ConstantPool::copy_cpool_bytes(int cpool_size,
2271 SymbolHash* tbl,
2272 unsigned char *bytes) {
2273 u2 idx1, idx2;
2274 jint size = 0;
2275 jint cnt = length();
2276 unsigned char *start_bytes = bytes;
2277
2278 for (jint idx = 1; idx < cnt; idx++) {
2279 u1 tag = tag_at(idx).value();
2280 jint ent_size = cpool_entry_size(idx);
2281
2282 assert(size + ent_size <= cpool_size, "Size mismatch");
2283
2284 *bytes = tag;
2285 DBG(printf("#%03hd tag=%03hd, ", (short)idx, (short)tag));
2286 switch(tag) {
2287 case JVM_CONSTANT_Invalid: {
2288 DBG(printf("JVM_CONSTANT_Invalid"));
2289 break;
2290 }
2291 case JVM_CONSTANT_Unicode: {
2292 assert(false, "Wrong constant pool tag: JVM_CONSTANT_Unicode");
2293 DBG(printf("JVM_CONSTANT_Unicode"));
2294 break;
2295 }
2296 case JVM_CONSTANT_Utf8: {
2297 Symbol* sym = symbol_at(idx);
2298 char* str = sym->as_utf8();
2299 // Warning! It's crashing on x86 with len = sym->utf8_length()
2300 int len = (int) strlen(str);
2301 Bytes::put_Java_u2((address) (bytes+1), (u2) len);
2302 for (int i = 0; i < len; i++) {
2303 bytes[3+i] = (u1) str[i];
2304 }
2305 DBG(printf("JVM_CONSTANT_Utf8: %s ", str));
2306 break;
2307 }
2308 case JVM_CONSTANT_Integer: {
2309 jint val = int_at(idx);
2310 Bytes::put_Java_u4((address) (bytes+1), *(u4*)&val);
2311 break;
2312 }
2313 case JVM_CONSTANT_Float: {
2314 jfloat val = float_at(idx);
2315 Bytes::put_Java_u4((address) (bytes+1), *(u4*)&val);
2316 break;
2317 }
2318 case JVM_CONSTANT_Long: {
2319 jlong val = long_at(idx);
2320 Bytes::put_Java_u8((address) (bytes+1), *(u8*)&val);
2321 idx++; // Long takes two cpool slots
2322 break;
2323 }
2324 case JVM_CONSTANT_Double: {
2325 jdouble val = double_at(idx);
2326 Bytes::put_Java_u8((address) (bytes+1), *(u8*)&val);
2327 idx++; // Double takes two cpool slots
2328 break;
2329 }
2330 case JVM_CONSTANT_Class:
2331 case JVM_CONSTANT_UnresolvedClass:
2332 case JVM_CONSTANT_UnresolvedClassInError: {
2333 *bytes = JVM_CONSTANT_Class;
2334 Symbol* sym = klass_name_at(idx);
2335 idx1 = tbl->symbol_to_value(sym);
2336 assert(idx1 != 0, "Have not found a hashtable entry");
2337 Bytes::put_Java_u2((address) (bytes+1), idx1);
2338 DBG(printf("JVM_CONSTANT_Class: idx=#%03hd, %s", idx1, sym->as_utf8()));
2339 break;
2340 }
2341 case JVM_CONSTANT_String: {
2342 *bytes = JVM_CONSTANT_String;
2343 Symbol* sym = unresolved_string_at(idx);
2344 idx1 = tbl->symbol_to_value(sym);
2345 assert(idx1 != 0, "Have not found a hashtable entry");
2346 Bytes::put_Java_u2((address) (bytes+1), idx1);
2347 DBG(printf("JVM_CONSTANT_String: idx=#%03hd, %s", idx1, sym->as_utf8()));
2348 break;
2349 }
2350 case JVM_CONSTANT_Fieldref:
2351 case JVM_CONSTANT_Methodref:
2352 case JVM_CONSTANT_InterfaceMethodref: {
2353 idx1 = uncached_klass_ref_index_at(idx);
2354 idx2 = uncached_name_and_type_ref_index_at(idx);
2355 Bytes::put_Java_u2((address) (bytes+1), idx1);
2356 Bytes::put_Java_u2((address) (bytes+3), idx2);
2357 DBG(printf("JVM_CONSTANT_Methodref: %hd %hd", idx1, idx2));
2358 break;
2359 }
2360 case JVM_CONSTANT_NameAndType: {
2361 idx1 = name_ref_index_at(idx);
2362 idx2 = signature_ref_index_at(idx);
2363 Bytes::put_Java_u2((address) (bytes+1), idx1);
2364 Bytes::put_Java_u2((address) (bytes+3), idx2);
2365 DBG(printf("JVM_CONSTANT_NameAndType: %hd %hd", idx1, idx2));
2366 break;
2367 }
2368 case JVM_CONSTANT_ClassIndex: {
2369 *bytes = JVM_CONSTANT_Class;
2370 idx1 = checked_cast<u2>(klass_index_at(idx));
2371 Bytes::put_Java_u2((address) (bytes+1), idx1);
2372 DBG(printf("JVM_CONSTANT_ClassIndex: %hd", idx1));
2373 break;
2374 }
2375 case JVM_CONSTANT_StringIndex: {
2376 *bytes = JVM_CONSTANT_String;
2377 idx1 = checked_cast<u2>(string_index_at(idx));
2378 Bytes::put_Java_u2((address) (bytes+1), idx1);
2379 DBG(printf("JVM_CONSTANT_StringIndex: %hd", idx1));
2380 break;
2381 }
2382 case JVM_CONSTANT_MethodHandle:
2383 case JVM_CONSTANT_MethodHandleInError: {
2384 *bytes = JVM_CONSTANT_MethodHandle;
2385 int kind = method_handle_ref_kind_at(idx);
2386 idx1 = checked_cast<u2>(method_handle_index_at(idx));
2387 *(bytes+1) = (unsigned char) kind;
2388 Bytes::put_Java_u2((address) (bytes+2), idx1);
2389 DBG(printf("JVM_CONSTANT_MethodHandle: %d %hd", kind, idx1));
2390 break;
2391 }
2392 case JVM_CONSTANT_MethodType:
2393 case JVM_CONSTANT_MethodTypeInError: {
2394 *bytes = JVM_CONSTANT_MethodType;
2395 idx1 = checked_cast<u2>(method_type_index_at(idx));
2396 Bytes::put_Java_u2((address) (bytes+1), idx1);
2397 DBG(printf("JVM_CONSTANT_MethodType: %hd", idx1));
2398 break;
2399 }
2400 case JVM_CONSTANT_Dynamic:
2401 case JVM_CONSTANT_DynamicInError: {
2402 *bytes = tag;
2403 idx1 = extract_low_short_from_int(*int_at_addr(idx));
2404 idx2 = extract_high_short_from_int(*int_at_addr(idx));
2405 assert(idx2 == bootstrap_name_and_type_ref_index_at(idx), "correct half of u4");
2406 Bytes::put_Java_u2((address) (bytes+1), idx1);
2407 Bytes::put_Java_u2((address) (bytes+3), idx2);
2408 DBG(printf("JVM_CONSTANT_Dynamic: %hd %hd", idx1, idx2));
2409 break;
2410 }
2411 case JVM_CONSTANT_InvokeDynamic: {
2412 *bytes = tag;
2413 idx1 = extract_low_short_from_int(*int_at_addr(idx));
2414 idx2 = extract_high_short_from_int(*int_at_addr(idx));
2415 assert(idx2 == bootstrap_name_and_type_ref_index_at(idx), "correct half of u4");
2416 Bytes::put_Java_u2((address) (bytes+1), idx1);
2417 Bytes::put_Java_u2((address) (bytes+3), idx2);
2418 DBG(printf("JVM_CONSTANT_InvokeDynamic: %hd %hd", idx1, idx2));
2419 break;
2420 }
2421 }
2422 DBG(printf("\n"));
2423 bytes += ent_size;
2424 size += ent_size;
2425 }
2426 assert(size == cpool_size, "Size mismatch");
2427
2428 // Keep temporarily for debugging until it's stable.
2429 DBG(print_cpool_bytes(cnt, start_bytes));
2430 return (int)(bytes - start_bytes);
2431 } /* end copy_cpool_bytes */
2432
2433 #undef DBG
2434
2435 bool ConstantPool::is_maybe_on_stack() const {
2436 // This method uses the similar logic as nmethod::is_maybe_on_stack()
2437 if (!Continuations::enabled()) {
2438 return false;
2439 }
2440
2441 // If the condition below is true, it means that the nmethod was found to
2442 // be alive the previous completed marking cycle.
2443 return cache()->gc_epoch() >= CodeCache::previous_completed_gc_marking_cycle();
2444 }
2445
2446 // For redefinition, if any methods found in loom stack chunks, the gc_epoch is
2447 // recorded in their constant pool cache. The on_stack-ness of the constant pool controls whether
2448 // memory for the method is reclaimed.
2449 bool ConstantPool::on_stack() const {
2450 if ((_flags &_on_stack) != 0) {
2451 return true;
2452 }
2453
2454 if (_cache == nullptr) {
2455 return false;
2456 }
2457
2458 return is_maybe_on_stack();
2459 }
2460
2461 void ConstantPool::set_on_stack(const bool value) {
2462 if (value) {
2463 // Only record if it's not already set.
2464 if (!on_stack()) {
2465 assert(!is_shared(), "should always be set for shared constant pools");
2466 _flags |= _on_stack;
2467 MetadataOnStackMark::record(this);
2468 }
2469 } else {
2470 // Clearing is done single-threadedly.
2471 if (!is_shared()) {
2472 _flags &= (u2)(~_on_stack);
2473 }
2474 }
2475 }
2476
2477 // Printing
2478
2479 void ConstantPool::print_on(outputStream* st) const {
2480 assert(is_constantPool(), "must be constantPool");
2481 st->print_cr("%s", internal_name());
2482 if (flags() != 0) {
2483 st->print(" - flags: 0x%x", flags());
2484 if (has_preresolution()) st->print(" has_preresolution");
2485 if (on_stack()) st->print(" on_stack");
2486 st->cr();
2487 }
2488 if (pool_holder() != nullptr) {
2489 st->print_cr(" - holder: " PTR_FORMAT, p2i(pool_holder()));
2490 }
2491 st->print_cr(" - cache: " PTR_FORMAT, p2i(cache()));
2492 st->print_cr(" - resolved_references: " PTR_FORMAT, p2i(resolved_references_or_null()));
2493 st->print_cr(" - reference_map: " PTR_FORMAT, p2i(reference_map()));
2494 st->print_cr(" - resolved_klasses: " PTR_FORMAT, p2i(resolved_klasses()));
2495 st->print_cr(" - cp length: %d", length());
2496
2497 for (int index = 1; index < length(); index++) { // Index 0 is unused
2498 ((ConstantPool*)this)->print_entry_on(index, st);
2499 switch (tag_at(index).value()) {
2500 case JVM_CONSTANT_Long :
2501 case JVM_CONSTANT_Double :
2502 index++; // Skip entry following eigth-byte constant
2503 }
2504
2505 }
2506 st->cr();
2507 }
2508
2509 // Print one constant pool entry
2510 void ConstantPool::print_entry_on(const int cp_index, outputStream* st) {
2511 EXCEPTION_MARK;
2512 st->print(" - %3d : ", cp_index);
2513 tag_at(cp_index).print_on(st);
2514 st->print(" : ");
2515 switch (tag_at(cp_index).value()) {
2516 case JVM_CONSTANT_Class :
2517 { Klass* k = klass_at(cp_index, CATCH);
2518 guarantee(k != nullptr, "need klass");
2519 k->print_value_on(st);
2520 st->print(" {" PTR_FORMAT "}", p2i(k));
2521 }
2522 break;
2523 case JVM_CONSTANT_Fieldref :
2524 case JVM_CONSTANT_Methodref :
2525 case JVM_CONSTANT_InterfaceMethodref :
2526 st->print("klass_index=%d", uncached_klass_ref_index_at(cp_index));
2527 st->print(" name_and_type_index=%d", uncached_name_and_type_ref_index_at(cp_index));
2528 break;
2529 case JVM_CONSTANT_String :
2530 unresolved_string_at(cp_index)->print_value_on(st);
2531 break;
2532 case JVM_CONSTANT_Integer :
2533 st->print("%d", int_at(cp_index));
2534 break;
2535 case JVM_CONSTANT_Float :
2536 st->print("%f", float_at(cp_index));
2537 break;
2538 case JVM_CONSTANT_Long :
2539 st->print_jlong(long_at(cp_index));
2540 break;
2541 case JVM_CONSTANT_Double :
2542 st->print("%lf", double_at(cp_index));
2543 break;
2544 case JVM_CONSTANT_NameAndType :
2545 st->print("name_index=%d", name_ref_index_at(cp_index));
2546 st->print(" signature_index=%d", signature_ref_index_at(cp_index));
2547 break;
2548 case JVM_CONSTANT_Utf8 :
2549 symbol_at(cp_index)->print_value_on(st);
2550 break;
2551 case JVM_CONSTANT_ClassIndex: {
2552 int name_index = *int_at_addr(cp_index);
2553 st->print("klass_index=%d ", name_index);
2554 symbol_at(name_index)->print_value_on(st);
2555 }
2556 break;
2557 case JVM_CONSTANT_UnresolvedClass : // fall-through
2558 case JVM_CONSTANT_UnresolvedClassInError: {
2559 CPKlassSlot kslot = klass_slot_at(cp_index);
2560 int resolved_klass_index = kslot.resolved_klass_index();
2561 int name_index = kslot.name_index();
2562 assert(tag_at(name_index).is_symbol(), "sanity");
2563 symbol_at(name_index)->print_value_on(st);
2564 }
2565 break;
2566 case JVM_CONSTANT_MethodHandle :
2567 case JVM_CONSTANT_MethodHandleInError :
2568 st->print("ref_kind=%d", method_handle_ref_kind_at(cp_index));
2569 st->print(" ref_index=%d", method_handle_index_at(cp_index));
2570 break;
2571 case JVM_CONSTANT_MethodType :
2572 case JVM_CONSTANT_MethodTypeInError :
2573 st->print("signature_index=%d", method_type_index_at(cp_index));
2574 break;
2575 case JVM_CONSTANT_Dynamic :
2576 case JVM_CONSTANT_DynamicInError :
2577 {
2578 st->print("bootstrap_method_index=%d", bootstrap_method_ref_index_at(cp_index));
2579 st->print(" type_index=%d", bootstrap_name_and_type_ref_index_at(cp_index));
2580 int argc = bootstrap_argument_count_at(cp_index);
2581 if (argc > 0) {
2582 for (int arg_i = 0; arg_i < argc; arg_i++) {
2583 int arg = bootstrap_argument_index_at(cp_index, arg_i);
2584 st->print((arg_i == 0 ? " arguments={%d" : ", %d"), arg);
2585 }
2586 st->print("}");
2587 }
2588 }
2589 break;
2590 case JVM_CONSTANT_InvokeDynamic :
2591 {
2592 st->print("bootstrap_method_index=%d", bootstrap_method_ref_index_at(cp_index));
2593 st->print(" name_and_type_index=%d", bootstrap_name_and_type_ref_index_at(cp_index));
2594 int argc = bootstrap_argument_count_at(cp_index);
2595 if (argc > 0) {
2596 for (int arg_i = 0; arg_i < argc; arg_i++) {
2597 int arg = bootstrap_argument_index_at(cp_index, arg_i);
2598 st->print((arg_i == 0 ? " arguments={%d" : ", %d"), arg);
2599 }
2600 st->print("}");
2601 }
2602 }
2603 break;
2604 default:
2605 ShouldNotReachHere();
2606 break;
2607 }
2608 st->cr();
2609 }
2610
2611 void ConstantPool::print_value_on(outputStream* st) const {
2612 assert(is_constantPool(), "must be constantPool");
2613 st->print("constant pool [%d]", length());
2614 if (has_preresolution()) st->print("/preresolution");
2615 if (operands() != nullptr) st->print("/operands[%d]", operands()->length());
2616 print_address_on(st);
2617 if (pool_holder() != nullptr) {
2618 st->print(" for ");
2619 pool_holder()->print_value_on(st);
2620 bool extra = (pool_holder()->constants() != this);
2621 if (extra) st->print(" (extra)");
2622 }
2623 if (cache() != nullptr) {
2624 st->print(" cache=" PTR_FORMAT, p2i(cache()));
2625 }
2626 }
2627
2628 // Verification
2629
2630 void ConstantPool::verify_on(outputStream* st) {
2631 guarantee(is_constantPool(), "object must be constant pool");
2632 for (int i = 0; i< length(); i++) {
2633 constantTag tag = tag_at(i);
2634 if (tag.is_klass() || tag.is_unresolved_klass()) {
2635 guarantee(klass_name_at(i)->refcount() != 0, "should have nonzero reference count");
2636 } else if (tag.is_symbol()) {
2637 Symbol* entry = symbol_at(i);
2638 guarantee(entry->refcount() != 0, "should have nonzero reference count");
2639 } else if (tag.is_string()) {
2640 Symbol* entry = unresolved_string_at(i);
2641 guarantee(entry->refcount() != 0, "should have nonzero reference count");
2642 }
2643 }
2644 if (pool_holder() != nullptr) {
2645 // Note: pool_holder() can be null in temporary constant pools
2646 // used during constant pool merging
2647 guarantee(pool_holder()->is_klass(), "should be klass");
2648 }
2649 }