1 /*
2 * Copyright (c) 1997, 2025, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "cds/aotConstantPoolResolver.hpp"
26 #include "cds/archiveBuilder.hpp"
27 #include "cds/cdsConfig.hpp"
28 #include "cds/heapShared.inline.hpp"
29 #include "classfile/classLoader.hpp"
30 #include "classfile/classLoaderData.hpp"
31 #include "classfile/javaClasses.inline.hpp"
32 #include "classfile/metadataOnStackMark.hpp"
33 #include "classfile/stringTable.hpp"
34 #include "classfile/systemDictionary.hpp"
35 #include "classfile/systemDictionaryShared.hpp"
36 #include "classfile/vmClasses.hpp"
37 #include "classfile/vmSymbols.hpp"
38 #include "code/codeCache.hpp"
39 #include "interpreter/bootstrapInfo.hpp"
40 #include "interpreter/linkResolver.hpp"
41 #include "jvm.h"
42 #include "logging/log.hpp"
43 #include "logging/logStream.hpp"
44 #include "memory/allocation.inline.hpp"
45 #include "memory/metadataFactory.hpp"
46 #include "memory/metaspaceClosure.hpp"
47 #include "memory/oopFactory.hpp"
48 #include "memory/resourceArea.hpp"
49 #include "memory/universe.hpp"
50 #include "oops/array.hpp"
51 #include "oops/constantPool.inline.hpp"
52 #include "oops/cpCache.inline.hpp"
53 #include "oops/fieldStreams.inline.hpp"
54 #include "oops/flatArrayKlass.hpp"
55 #include "oops/instanceKlass.hpp"
56 #include "oops/klass.inline.hpp"
57 #include "oops/objArrayKlass.hpp"
58 #include "oops/objArrayOop.inline.hpp"
59 #include "oops/oop.inline.hpp"
60 #include "oops/refArrayOop.hpp"
61 #include "oops/typeArrayOop.inline.hpp"
62 #include "prims/jvmtiExport.hpp"
63 #include "runtime/atomicAccess.hpp"
64 #include "runtime/fieldDescriptor.inline.hpp"
65 #include "runtime/handles.inline.hpp"
66 #include "runtime/init.hpp"
67 #include "runtime/javaCalls.hpp"
68 #include "runtime/javaThread.inline.hpp"
69 #include "runtime/perfData.hpp"
70 #include "runtime/signature.hpp"
71 #include "runtime/vframe.inline.hpp"
72 #include "utilities/checkedCast.hpp"
73 #include "utilities/copy.hpp"
74
75 ConstantPool* ConstantPool::allocate(ClassLoaderData* loader_data, int length, TRAPS) {
76 Array<u1>* tags = MetadataFactory::new_array<u1>(loader_data, length, 0, CHECK_NULL);
77 int size = ConstantPool::size(length);
78 return new (loader_data, size, MetaspaceObj::ConstantPoolType, THREAD) ConstantPool(tags);
79 }
80
81 void ConstantPool::copy_fields(const ConstantPool* orig) {
82 // Preserve dynamic constant information from the original pool
83 if (orig->has_dynamic_constant()) {
84 set_has_dynamic_constant();
85 }
86
87 set_major_version(orig->major_version());
88 set_minor_version(orig->minor_version());
89
90 set_source_file_name_index(orig->source_file_name_index());
91 set_generic_signature_index(orig->generic_signature_index());
92 }
93
94 #ifdef ASSERT
95
96 // MetaspaceObj allocation invariant is calloc equivalent memory
97 // simple verification of this here (JVM_CONSTANT_Invalid == 0 )
98 static bool tag_array_is_zero_initialized(Array<u1>* tags) {
99 assert(tags != nullptr, "invariant");
100 const int length = tags->length();
101 for (int index = 0; index < length; ++index) {
102 if (JVM_CONSTANT_Invalid != tags->at(index)) {
103 return false;
104 }
105 }
106 return true;
107 }
108
109 #endif
110
111 ConstantPool::ConstantPool() {
112 assert(CDSConfig::is_dumping_static_archive() || CDSConfig::is_using_archive(), "only for CDS");
113 }
114
115 ConstantPool::ConstantPool(Array<u1>* tags) :
116 _tags(tags),
117 _length(tags->length()) {
118
119 assert(_tags != nullptr, "invariant");
120 assert(tags->length() == _length, "invariant");
121 assert(tag_array_is_zero_initialized(tags), "invariant");
122 assert(0 == flags(), "invariant");
123 assert(0 == version(), "invariant");
124 assert(nullptr == _pool_holder, "invariant");
125 }
126
127 void ConstantPool::deallocate_contents(ClassLoaderData* loader_data) {
128 if (cache() != nullptr) {
129 MetadataFactory::free_metadata(loader_data, cache());
130 set_cache(nullptr);
131 }
132
133 MetadataFactory::free_array<Klass*>(loader_data, resolved_klasses());
134 set_resolved_klasses(nullptr);
135
136 MetadataFactory::free_array<jushort>(loader_data, operands());
137 set_operands(nullptr);
138
139 release_C_heap_structures();
140
141 // free tag array
142 MetadataFactory::free_array<u1>(loader_data, tags());
143 set_tags(nullptr);
144 }
145
146 void ConstantPool::release_C_heap_structures() {
147 // walk constant pool and decrement symbol reference counts
148 unreference_symbols();
149 }
150
151 void ConstantPool::metaspace_pointers_do(MetaspaceClosure* it) {
152 log_trace(aot)("Iter(ConstantPool): %p", this);
153
154 it->push(&_tags, MetaspaceClosure::_writable);
155 it->push(&_cache);
156 it->push(&_pool_holder);
157 it->push(&_operands);
158 it->push(&_resolved_klasses, MetaspaceClosure::_writable);
159
160 for (int i = 0; i < length(); i++) {
161 // The only MSO's embedded in the CP entries are Symbols:
162 // JVM_CONSTANT_String
163 // JVM_CONSTANT_Utf8
164 constantTag ctag = tag_at(i);
165 if (ctag.is_string() || ctag.is_utf8()) {
166 it->push(symbol_at_addr(i));
167 }
168 }
169 }
170
171 objArrayOop ConstantPool::resolved_references() const {
172 return _cache->resolved_references();
173 }
174
175 // Called from outside constant pool resolution where a resolved_reference array
176 // may not be present.
177 objArrayOop ConstantPool::resolved_references_or_null() const {
178 if (_cache == nullptr) {
179 return nullptr;
180 } else {
181 return _cache->resolved_references();
182 }
183 }
184
185 oop ConstantPool::resolved_reference_at(int index) const {
186 oop result = resolved_references()->obj_at(index);
187 assert(oopDesc::is_oop_or_null(result), "Must be oop");
188 return result;
189 }
190
191 // Use a CAS for multithreaded access
192 oop ConstantPool::set_resolved_reference_at(int index, oop new_result) {
193 assert(oopDesc::is_oop_or_null(new_result), "Must be oop");
194 return refArrayOopDesc::cast(resolved_references())->replace_if_null(index, new_result);
195 }
196
197 // Create resolved_references array and mapping array for original cp indexes
198 // The ldc bytecode was rewritten to have the resolved reference array index so need a way
199 // to map it back for resolving and some unlikely miscellaneous uses.
200 // The objects created by invokedynamic are appended to this list.
201 void ConstantPool::initialize_resolved_references(ClassLoaderData* loader_data,
202 const intStack& reference_map,
203 int constant_pool_map_length,
204 TRAPS) {
205 // Initialized the resolved object cache.
206 int map_length = reference_map.length();
207 if (map_length > 0) {
208 // Only need mapping back to constant pool entries. The map isn't used for
209 // invokedynamic resolved_reference entries. For invokedynamic entries,
210 // the constant pool cache index has the mapping back to both the constant
211 // pool and to the resolved reference index.
212 if (constant_pool_map_length > 0) {
213 Array<u2>* om = MetadataFactory::new_array<u2>(loader_data, constant_pool_map_length, CHECK);
214
215 for (int i = 0; i < constant_pool_map_length; i++) {
216 int x = reference_map.at(i);
217 assert(x == (int)(jushort) x, "klass index is too big");
218 om->at_put(i, (jushort)x);
219 }
220 set_reference_map(om);
221 }
222
223 // Create Java array for holding resolved strings, methodHandles,
224 // methodTypes, invokedynamic and invokehandle appendix objects, etc.
225 objArrayOop stom = oopFactory::new_objArray(vmClasses::Object_klass(), map_length, CHECK);
226 HandleMark hm(THREAD);
227 Handle refs_handle (THREAD, stom); // must handleize.
228 set_resolved_references(loader_data->add_handle(refs_handle));
229
230 // Create a "scratch" copy of the resolved references array to archive
231 if (CDSConfig::is_dumping_heap()) {
232 objArrayOop scratch_references = oopFactory::new_objArray(vmClasses::Object_klass(), map_length, CHECK);
233 HeapShared::add_scratch_resolved_references(this, scratch_references);
234 }
235 }
236 }
237
238 void ConstantPool::allocate_resolved_klasses(ClassLoaderData* loader_data, int num_klasses, TRAPS) {
239 // A ConstantPool can't possibly have 0xffff valid class entries,
240 // because entry #0 must be CONSTANT_Invalid, and each class entry must refer to a UTF8
241 // entry for the class's name. So at most we will have 0xfffe class entries.
242 // This allows us to use 0xffff (ConstantPool::_temp_resolved_klass_index) to indicate
243 // UnresolvedKlass entries that are temporarily created during class redefinition.
244 assert(num_klasses < CPKlassSlot::_temp_resolved_klass_index, "sanity");
245 assert(resolved_klasses() == nullptr, "sanity");
246 Array<Klass*>* rk = MetadataFactory::new_array<Klass*>(loader_data, num_klasses, CHECK);
247 set_resolved_klasses(rk);
248 }
249
250 void ConstantPool::initialize_unresolved_klasses(ClassLoaderData* loader_data, TRAPS) {
251 int len = length();
252 int num_klasses = 0;
253 for (int i = 1; i <len; i++) {
254 switch (tag_at(i).value()) {
255 case JVM_CONSTANT_ClassIndex:
256 {
257 const int class_index = klass_index_at(i);
258 unresolved_klass_at_put(i, class_index, num_klasses++);
259 }
260 break;
261 #ifndef PRODUCT
262 case JVM_CONSTANT_Class:
263 case JVM_CONSTANT_UnresolvedClass:
264 case JVM_CONSTANT_UnresolvedClassInError:
265 // All of these should have been reverted back to Unresolved before calling
266 // this function.
267 ShouldNotReachHere();
268 #endif
269 }
270 }
271 allocate_resolved_klasses(loader_data, num_klasses, THREAD);
272 }
273
274 // Hidden class support:
275 void ConstantPool::klass_at_put(int class_index, Klass* k) {
276 assert(k != nullptr, "must be valid klass");
277 CPKlassSlot kslot = klass_slot_at(class_index);
278 int resolved_klass_index = kslot.resolved_klass_index();
279 Klass** adr = resolved_klasses()->adr_at(resolved_klass_index);
280 AtomicAccess::release_store(adr, k);
281
282 // The interpreter assumes when the tag is stored, the klass is resolved
283 // and the Klass* non-null, so we need hardware store ordering here.
284 release_tag_at_put(class_index, JVM_CONSTANT_Class);
285 }
286
287 #if INCLUDE_CDS_JAVA_HEAP
288 template <typename Function>
289 void ConstantPool::iterate_archivable_resolved_references(Function function) {
290 objArrayOop rr = resolved_references();
291 if (rr != nullptr && cache() != nullptr && CDSConfig::is_dumping_method_handles()) {
292 Array<ResolvedIndyEntry>* indy_entries = cache()->resolved_indy_entries();
293 if (indy_entries != nullptr) {
294 for (int i = 0; i < indy_entries->length(); i++) {
295 ResolvedIndyEntry *rie = indy_entries->adr_at(i);
296 if (rie->is_resolved() && AOTConstantPoolResolver::is_resolution_deterministic(this, rie->constant_pool_index())) {
297 int rr_index = rie->resolved_references_index();
298 assert(resolved_reference_at(rr_index) != nullptr, "must exist");
299 function(rr_index);
300
301 // Save the BSM as well (sometimes the JIT looks up the BSM it for replay)
302 int indy_cp_index = rie->constant_pool_index();
303 int bsm_mh_cp_index = bootstrap_method_ref_index_at(indy_cp_index);
304 int bsm_rr_index = cp_to_object_index(bsm_mh_cp_index);
305 assert(resolved_reference_at(bsm_rr_index) != nullptr, "must exist");
306 function(bsm_rr_index);
307 }
308 }
309 }
310
311 Array<ResolvedMethodEntry>* method_entries = cache()->resolved_method_entries();
312 if (method_entries != nullptr) {
313 for (int i = 0; i < method_entries->length(); i++) {
314 ResolvedMethodEntry* rme = method_entries->adr_at(i);
315 if (rme->is_resolved(Bytecodes::_invokehandle) && rme->has_appendix() &&
316 cache()->can_archive_resolved_method(this, rme)) {
317 int rr_index = rme->resolved_references_index();
318 assert(resolved_reference_at(rr_index) != nullptr, "must exist");
319 function(rr_index);
320 }
321 }
322 }
323 }
324 }
325
326 // Returns the _resolved_reference array after removing unarchivable items from it.
327 // Returns null if this class is not supported, or _resolved_reference doesn't exist.
328 objArrayOop ConstantPool::prepare_resolved_references_for_archiving() {
329 if (_cache == nullptr) {
330 return nullptr; // nothing to do
331 }
332
333 InstanceKlass *ik = pool_holder();
334 if (!SystemDictionaryShared::is_builtin_loader(ik->class_loader_data())) {
335 // Archiving resolved references for classes from non-builtin loaders
336 // is not yet supported.
337 return nullptr;
338 }
339
340 objArrayOop rr = resolved_references();
341 if (rr != nullptr) {
342 ResourceMark rm;
343 int rr_len = rr->length();
344 GrowableArray<bool> keep_resolved_refs(rr_len, rr_len, false);
345
346 iterate_archivable_resolved_references([&](int rr_index) {
347 keep_resolved_refs.at_put(rr_index, true);
348 });
349
350 objArrayOop scratch_rr = HeapShared::scratch_resolved_references(this);
351 Array<u2>* ref_map = reference_map();
352 int ref_map_len = ref_map == nullptr ? 0 : ref_map->length();
353 for (int i = 0; i < rr_len; i++) {
354 oop obj = rr->obj_at(i);
355 scratch_rr->obj_at_put(i, nullptr);
356 if (obj != nullptr) {
357 if (i < ref_map_len) {
358 int index = object_to_cp_index(i);
359 if (tag_at(index).is_string()) {
360 assert(java_lang_String::is_instance(obj), "must be");
361 if (!HeapShared::is_string_too_large_to_archive(obj)) {
362 scratch_rr->obj_at_put(i, obj);
363 }
364 continue;
365 }
366 }
367
368 if (keep_resolved_refs.at(i)) {
369 scratch_rr->obj_at_put(i, obj);
370 }
371 }
372 }
373 return scratch_rr;
374 }
375 return rr;
376 }
377 #endif
378
379 #if INCLUDE_CDS
380 // CDS support. Create a new resolved_references array.
381 void ConstantPool::restore_unshareable_info(TRAPS) {
382 if (!_pool_holder->is_linked() && !_pool_holder->is_rewritten()) {
383 return;
384 }
385 assert(is_constantPool(), "ensure C++ vtable is restored");
386 assert(on_stack(), "should always be set for constant pools in AOT cache");
387 assert(in_aot_cache(), "should always be set for constant pools in AOT cache");
388 if (is_for_method_handle_intrinsic()) {
389 // See the same check in remove_unshareable_info() below.
390 assert(cache() == nullptr, "must not have cpCache");
391 return;
392 }
393 assert(_cache != nullptr, "constant pool _cache should not be null");
394
395 // Only create the new resolved references array if it hasn't been attempted before
396 if (resolved_references() != nullptr) return;
397
398 if (vmClasses::Object_klass_is_loaded()) {
399 ClassLoaderData* loader_data = pool_holder()->class_loader_data();
400 #if INCLUDE_CDS_JAVA_HEAP
401 if (HeapShared::is_archived_heap_in_use() &&
402 _cache->archived_references() != nullptr) {
403 oop archived = _cache->archived_references();
404 // Create handle for the archived resolved reference array object
405 HandleMark hm(THREAD);
406 Handle refs_handle(THREAD, archived);
407 set_resolved_references(loader_data->add_handle(refs_handle));
408 _cache->clear_archived_references();
409 } else
410 #endif
411 {
412 // No mapped archived resolved reference array
413 // Recreate the object array and add to ClassLoaderData.
414 int map_length = resolved_reference_length();
415 if (map_length > 0) {
416 objArrayOop stom = oopFactory::new_objArray(vmClasses::Object_klass(), map_length, CHECK);
417 HandleMark hm(THREAD);
418 Handle refs_handle(THREAD, stom); // must handleize.
419 set_resolved_references(loader_data->add_handle(refs_handle));
420 }
421 }
422 }
423
424 if (CDSConfig::is_dumping_final_static_archive() && CDSConfig::is_dumping_heap() && resolved_references() != nullptr) {
425 objArrayOop scratch_references = oopFactory::new_objArray(vmClasses::Object_klass(), resolved_references()->length(), CHECK);
426 HeapShared::add_scratch_resolved_references(this, scratch_references);
427 }
428 }
429
430 void ConstantPool::remove_unshareable_info() {
431 // ConstantPools in AOT cache are in the RO region, so the _flags cannot be modified.
432 // The _on_stack flag is used to prevent ConstantPools from deallocation during
433 // class redefinition. Since such ConstantPools cannot be deallocated anyway,
434 // we always set _on_stack to true to avoid having to change _flags during runtime.
435 _flags |= (_on_stack | _in_aot_cache);
436
437 if (is_for_method_handle_intrinsic()) {
438 // This CP was created by Method::make_method_handle_intrinsic() and has nothing
439 // that need to be removed/restored. It has no cpCache since the intrinsic methods
440 // don't have any bytecodes.
441 assert(cache() == nullptr, "must not have cpCache");
442 return;
443 }
444
445 bool update_resolved_reference = true;
446 if (CDSConfig::is_dumping_final_static_archive()) {
447 ConstantPool* src_cp = ArchiveBuilder::current()->get_source_addr(this);
448 InstanceKlass* src_holder = src_cp->pool_holder();
449 if (src_holder->defined_by_other_loaders()) {
450 // Unregistered classes are not loaded in the AOT assembly phase. The resolved reference length
451 // is already saved during the training run.
452 precond(!src_holder->is_loaded());
453 precond(resolved_reference_length() >= 0);
454 precond(resolved_references() == nullptr);
455 update_resolved_reference = false;
456 }
457 }
458
459 // resolved_references(): remember its length. If it cannot be restored
460 // from the archived heap objects at run time, we need to dynamically allocate it.
461 if (update_resolved_reference && cache() != nullptr) {
462 set_resolved_reference_length(
463 resolved_references() != nullptr ? resolved_references()->length() : 0);
464 set_resolved_references(OopHandle());
465 }
466 remove_unshareable_entries();
467 }
468
469 static const char* get_type(Klass* k) {
470 const char* type;
471 Klass* src_k;
472 if (ArchiveBuilder::is_active() && ArchiveBuilder::current()->is_in_buffer_space(k)) {
473 src_k = ArchiveBuilder::current()->get_source_addr(k);
474 } else {
475 src_k = k;
476 }
477
478 if (src_k->is_objArray_klass()) {
479 src_k = ObjArrayKlass::cast(src_k)->bottom_klass();
480 assert(!src_k->is_objArray_klass(), "sanity");
481 assert(src_k->is_instance_klass() || src_k->is_typeArray_klass(), "Sanity check");
482 }
483
484 if (src_k->is_typeArray_klass()) {
485 type = "prim";
486 } else {
487 InstanceKlass* src_ik = InstanceKlass::cast(src_k);
488 if (src_ik->defined_by_boot_loader()) {
489 return "boot";
490 } else if (src_ik->defined_by_platform_loader()) {
491 return "plat";
492 } else if (src_ik->defined_by_app_loader()) {
493 return "app";
494 } else {
495 return "unreg";
496 }
497 }
498
499 return type;
500 }
501
502 void ConstantPool::remove_unshareable_entries() {
503 ResourceMark rm;
504 log_info(aot, resolve)("Archiving CP entries for %s", pool_holder()->name()->as_C_string());
505 for (int cp_index = 1; cp_index < length(); cp_index++) { // cp_index 0 is unused
506 int cp_tag = tag_at(cp_index).value();
507 switch (cp_tag) {
508 case JVM_CONSTANT_UnresolvedClass:
509 ArchiveBuilder::alloc_stats()->record_klass_cp_entry(false, false);
510 break;
511 case JVM_CONSTANT_UnresolvedClassInError:
512 tag_at_put(cp_index, JVM_CONSTANT_UnresolvedClass);
513 ArchiveBuilder::alloc_stats()->record_klass_cp_entry(false, true);
514 break;
515 case JVM_CONSTANT_MethodHandleInError:
516 tag_at_put(cp_index, JVM_CONSTANT_MethodHandle);
517 break;
518 case JVM_CONSTANT_MethodTypeInError:
519 tag_at_put(cp_index, JVM_CONSTANT_MethodType);
520 break;
521 case JVM_CONSTANT_DynamicInError:
522 tag_at_put(cp_index, JVM_CONSTANT_Dynamic);
523 break;
524 case JVM_CONSTANT_Class:
525 remove_resolved_klass_if_non_deterministic(cp_index);
526 break;
527 default:
528 break;
529 }
530 }
531
532 if (cache() != nullptr) {
533 // cache() is null if this class is not yet linked.
534 cache()->remove_unshareable_info();
535 }
536 }
537
538 void ConstantPool::remove_resolved_klass_if_non_deterministic(int cp_index) {
539 assert(ArchiveBuilder::current()->is_in_buffer_space(this), "must be");
540 assert(tag_at(cp_index).is_klass(), "must be resolved");
541
542 bool can_archive;
543 Klass* k = nullptr;
544
545 if (CDSConfig::is_dumping_preimage_static_archive()) {
546 can_archive = false;
547 } else {
548 k = resolved_klass_at(cp_index);
549 if (k == nullptr) {
550 // We'd come here if the referenced class has been excluded via
551 // SystemDictionaryShared::is_excluded_class(). As a result, ArchiveBuilder
552 // has cleared the resolved_klasses()->at(...) pointer to null. Thus, we
553 // need to revert the tag to JVM_CONSTANT_UnresolvedClass.
554 can_archive = false;
555 } else {
556 ConstantPool* src_cp = ArchiveBuilder::current()->get_source_addr(this);
557 can_archive = AOTConstantPoolResolver::is_resolution_deterministic(src_cp, cp_index);
558 }
559 }
560
561 if (!can_archive) {
562 int resolved_klass_index = klass_slot_at(cp_index).resolved_klass_index();
563 // This might be at a safepoint but do this in the right order.
564 tag_at_put(cp_index, JVM_CONSTANT_UnresolvedClass);
565 resolved_klasses()->at_put(resolved_klass_index, nullptr);
566 }
567
568 LogStreamHandle(Trace, aot, resolve) log;
569 if (log.is_enabled()) {
570 ResourceMark rm;
571 log.print("%s klass CP entry [%3d]: %s %s",
572 (can_archive ? "archived" : "reverted"),
573 cp_index, pool_holder()->name()->as_C_string(), get_type(pool_holder()));
574 if (can_archive) {
575 log.print(" => %s %s%s", k->name()->as_C_string(), get_type(k),
576 (!k->is_instance_klass() || pool_holder()->is_subtype_of(k)) ? "" : " (not supertype)");
577 } else {
578 Symbol* name = klass_name_at(cp_index);
579 log.print(" => %s", name->as_C_string());
580 }
581 }
582
583 ArchiveBuilder::alloc_stats()->record_klass_cp_entry(can_archive, /*reverted=*/!can_archive);
584 }
585 #endif // INCLUDE_CDS
586
587 int ConstantPool::cp_to_object_index(int cp_index) {
588 // this is harder don't do this so much.
589 int i = reference_map()->find(checked_cast<u2>(cp_index));
590 // We might not find the index for jsr292 call.
591 return (i < 0) ? _no_index_sentinel : i;
592 }
593
594 void ConstantPool::string_at_put(int obj_index, oop str) {
595 oop result = set_resolved_reference_at(obj_index, str);
596 assert(result == nullptr || result == str, "Only set once or to the same string.");
597 }
598
599 void ConstantPool::trace_class_resolution(const constantPoolHandle& this_cp, Klass* k) {
600 ResourceMark rm;
601 int line_number = -1;
602 const char * source_file = nullptr;
603 if (JavaThread::current()->has_last_Java_frame()) {
604 // try to identify the method which called this function.
605 vframeStream vfst(JavaThread::current());
606 if (!vfst.at_end()) {
607 line_number = vfst.method()->line_number_from_bci(vfst.bci());
608 Symbol* s = vfst.method()->method_holder()->source_file_name();
609 if (s != nullptr) {
610 source_file = s->as_C_string();
611 }
612 }
613 }
614 if (k != this_cp->pool_holder()) {
615 // only print something if the classes are different
616 if (source_file != nullptr) {
617 log_debug(class, resolve)("%s %s %s:%d",
618 this_cp->pool_holder()->external_name(),
619 k->external_name(), source_file, line_number);
620 } else {
621 log_debug(class, resolve)("%s %s",
622 this_cp->pool_holder()->external_name(),
623 k->external_name());
624 }
625 }
626 }
627
628 void check_is_inline_type(Klass* k, TRAPS) {
629 if (!k->is_inline_klass()) {
630 THROW(vmSymbols::java_lang_IncompatibleClassChangeError());
631 }
632 }
633
634 Klass* ConstantPool::klass_at_impl(const constantPoolHandle& this_cp, int cp_index,
635 TRAPS) {
636 JavaThread* javaThread = THREAD;
637
638 // A resolved constantPool entry will contain a Klass*, otherwise a Symbol*.
639 // It is not safe to rely on the tag bit's here, since we don't have a lock, and
640 // the entry and tag is not updated atomically.
641 CPKlassSlot kslot = this_cp->klass_slot_at(cp_index);
642 int resolved_klass_index = kslot.resolved_klass_index();
643 int name_index = kslot.name_index();
644 assert(this_cp->tag_at(name_index).is_symbol(), "sanity");
645
646 // The tag must be JVM_CONSTANT_Class in order to read the correct value from
647 // the unresolved_klasses() array.
648 if (this_cp->tag_at(cp_index).is_klass()) {
649 Klass* klass = this_cp->resolved_klasses()->at(resolved_klass_index);
650 assert(klass != nullptr, "must be resolved");
651 return klass;
652 }
653
654 // This tag doesn't change back to unresolved class unless at a safepoint.
655 if (this_cp->tag_at(cp_index).is_unresolved_klass_in_error()) {
656 // The original attempt to resolve this constant pool entry failed so find the
657 // class of the original error and throw another error of the same class
658 // (JVMS 5.4.3).
659 // If there is a detail message, pass that detail message to the error.
660 // The JVMS does not strictly require us to duplicate the same detail message,
661 // or any internal exception fields such as cause or stacktrace. But since the
662 // detail message is often a class name or other literal string, we will repeat it
663 // if we can find it in the symbol table.
664 throw_resolution_error(this_cp, cp_index, CHECK_NULL);
665 ShouldNotReachHere();
666 }
667
668 HandleMark hm(THREAD);
669 Handle mirror_handle;
670 Symbol* name = this_cp->symbol_at(name_index);
671 bool inline_type_signature = false;
672 Handle loader (THREAD, this_cp->pool_holder()->class_loader());
673
674 Klass* k;
675 {
676 // Turn off the single stepping while doing class resolution
677 JvmtiHideSingleStepping jhss(javaThread);
678 k = SystemDictionary::resolve_or_fail(name, loader, true, THREAD);
679 } // JvmtiHideSingleStepping jhss(javaThread);
680 if (inline_type_signature) {
681 name->decrement_refcount();
682 }
683
684 if (!HAS_PENDING_EXCEPTION) {
685 // preserve the resolved klass from unloading
686 mirror_handle = Handle(THREAD, k->java_mirror());
687 // Do access check for klasses
688 verify_constant_pool_resolve(this_cp, k, THREAD);
689 }
690
691 if (!HAS_PENDING_EXCEPTION && inline_type_signature) {
692 check_is_inline_type(k, THREAD);
693 }
694
695 if (!HAS_PENDING_EXCEPTION) {
696 Klass* bottom_klass = nullptr;
697 if (k->is_objArray_klass()) {
698 bottom_klass = ObjArrayKlass::cast(k)->bottom_klass();
699 assert(bottom_klass != nullptr, "Should be set");
700 assert(bottom_klass->is_instance_klass() || bottom_klass->is_typeArray_klass(), "Sanity check");
701 } else if (k->is_flatArray_klass()) {
702 bottom_klass = FlatArrayKlass::cast(k)->element_klass();
703 assert(bottom_klass != nullptr, "Should be set");
704 }
705 }
706
707 // Failed to resolve class. We must record the errors so that subsequent attempts
708 // to resolve this constant pool entry fail with the same error (JVMS 5.4.3).
709 if (HAS_PENDING_EXCEPTION) {
710 save_and_throw_exception(this_cp, cp_index, constantTag(JVM_CONSTANT_UnresolvedClass), CHECK_NULL);
711 // If CHECK_NULL above doesn't return the exception, that means that
712 // some other thread has beaten us and has resolved the class.
713 // To preserve old behavior, we return the resolved class.
714 Klass* klass = this_cp->resolved_klasses()->at(resolved_klass_index);
715 assert(klass != nullptr, "must be resolved if exception was cleared");
716 return klass;
717 }
718
719 // logging for class+resolve.
720 if (log_is_enabled(Debug, class, resolve)){
721 trace_class_resolution(this_cp, k);
722 }
723
724 // The interpreter assumes when the tag is stored, the klass is resolved
725 // and the Klass* stored in _resolved_klasses is non-null, so we need
726 // hardware store ordering here.
727 // We also need to CAS to not overwrite an error from a racing thread.
728 Klass** adr = this_cp->resolved_klasses()->adr_at(resolved_klass_index);
729 AtomicAccess::release_store(adr, k);
730
731 jbyte old_tag = AtomicAccess::cmpxchg((jbyte*)this_cp->tag_addr_at(cp_index),
732 (jbyte)JVM_CONSTANT_UnresolvedClass,
733 (jbyte)JVM_CONSTANT_Class);
734
735 // We need to recheck exceptions from racing thread and return the same.
736 if (old_tag == JVM_CONSTANT_UnresolvedClassInError) {
737 // Remove klass.
738 AtomicAccess::store(adr, (Klass*)nullptr);
739 throw_resolution_error(this_cp, cp_index, CHECK_NULL);
740 }
741
742 return k;
743 }
744
745
746 // Does not update ConstantPool* - to avoid any exception throwing. Used
747 // by compiler and exception handling. Also used to avoid classloads for
748 // instanceof operations. Returns null if the class has not been loaded or
749 // if the verification of constant pool failed
750 Klass* ConstantPool::klass_at_if_loaded(const constantPoolHandle& this_cp, int which) {
751 CPKlassSlot kslot = this_cp->klass_slot_at(which);
752 int resolved_klass_index = kslot.resolved_klass_index();
753 int name_index = kslot.name_index();
754 assert(this_cp->tag_at(name_index).is_symbol(), "sanity");
755
756 if (this_cp->tag_at(which).is_klass()) {
757 Klass* k = this_cp->resolved_klasses()->at(resolved_klass_index);
758 assert(k != nullptr, "must be resolved");
759 return k;
760 } else if (this_cp->tag_at(which).is_unresolved_klass_in_error()) {
761 return nullptr;
762 } else {
763 Thread* current = Thread::current();
764 HandleMark hm(current);
765 Symbol* name = this_cp->symbol_at(name_index);
766 oop loader = this_cp->pool_holder()->class_loader();
767 Handle h_loader (current, loader);
768 Klass* k = SystemDictionary::find_instance_klass(current, name, h_loader);
769
770 // Avoid constant pool verification at a safepoint, as it takes the Module_lock.
771 if (k != nullptr && current->is_Java_thread()) {
772 // Make sure that resolving is legal
773 JavaThread* THREAD = JavaThread::cast(current); // For exception macros.
774 ExceptionMark em(THREAD);
775 // return null if verification fails
776 verify_constant_pool_resolve(this_cp, k, THREAD);
777 if (HAS_PENDING_EXCEPTION) {
778 CLEAR_PENDING_EXCEPTION;
779 return nullptr;
780 }
781 return k;
782 } else {
783 return k;
784 }
785 }
786 }
787
788 Method* ConstantPool::method_at_if_loaded(const constantPoolHandle& cpool,
789 int which) {
790 if (cpool->cache() == nullptr) return nullptr; // nothing to load yet
791 if (!(which >= 0 && which < cpool->resolved_method_entries_length())) {
792 // FIXME: should be an assert
793 log_debug(class, resolve)("bad operand %d in:", which); cpool->print();
794 return nullptr;
795 }
796 return cpool->cache()->method_if_resolved(which);
797 }
798
799
800 bool ConstantPool::has_appendix_at_if_loaded(const constantPoolHandle& cpool, int which, Bytecodes::Code code) {
801 if (cpool->cache() == nullptr) return false; // nothing to load yet
802 if (code == Bytecodes::_invokedynamic) {
803 return cpool->resolved_indy_entry_at(which)->has_appendix();
804 } else {
805 return cpool->resolved_method_entry_at(which)->has_appendix();
806 }
807 }
808
809 oop ConstantPool::appendix_at_if_loaded(const constantPoolHandle& cpool, int which, Bytecodes::Code code) {
810 if (cpool->cache() == nullptr) return nullptr; // nothing to load yet
811 if (code == Bytecodes::_invokedynamic) {
812 return cpool->resolved_reference_from_indy(which);
813 } else {
814 return cpool->cache()->appendix_if_resolved(which);
815 }
816 }
817
818
819 bool ConstantPool::has_local_signature_at_if_loaded(const constantPoolHandle& cpool, int which, Bytecodes::Code code) {
820 if (cpool->cache() == nullptr) return false; // nothing to load yet
821 if (code == Bytecodes::_invokedynamic) {
822 return cpool->resolved_indy_entry_at(which)->has_local_signature();
823 } else {
824 return cpool->resolved_method_entry_at(which)->has_local_signature();
825 }
826 }
827
828 // Translate index, which could be CPCache index or Indy index, to a constant pool index
829 int ConstantPool::to_cp_index(int index, Bytecodes::Code code) {
830 assert(cache() != nullptr, "'index' is a rewritten index so this class must have been rewritten");
831 switch(code) {
832 case Bytecodes::_invokedynamic:
833 return invokedynamic_bootstrap_ref_index_at(index);
834 case Bytecodes::_getfield:
835 case Bytecodes::_getstatic:
836 case Bytecodes::_putfield:
837 case Bytecodes::_putstatic:
838 return resolved_field_entry_at(index)->constant_pool_index();
839 case Bytecodes::_invokeinterface:
840 case Bytecodes::_invokehandle:
841 case Bytecodes::_invokespecial:
842 case Bytecodes::_invokestatic:
843 case Bytecodes::_invokevirtual:
844 case Bytecodes::_fast_invokevfinal: // Bytecode interpreter uses this
845 return resolved_method_entry_at(index)->constant_pool_index();
846 default:
847 fatal("Unexpected bytecode: %s", Bytecodes::name(code));
848 }
849 }
850
851 bool ConstantPool::is_resolved(int index, Bytecodes::Code code) {
852 assert(cache() != nullptr, "'index' is a rewritten index so this class must have been rewritten");
853 switch(code) {
854 case Bytecodes::_invokedynamic:
855 return resolved_indy_entry_at(index)->is_resolved();
856
857 case Bytecodes::_getfield:
858 case Bytecodes::_getstatic:
859 case Bytecodes::_putfield:
860 case Bytecodes::_putstatic:
861 return resolved_field_entry_at(index)->is_resolved(code);
862
863 case Bytecodes::_invokeinterface:
864 case Bytecodes::_invokehandle:
865 case Bytecodes::_invokespecial:
866 case Bytecodes::_invokestatic:
867 case Bytecodes::_invokevirtual:
868 case Bytecodes::_fast_invokevfinal: // Bytecode interpreter uses this
869 return resolved_method_entry_at(index)->is_resolved(code);
870
871 default:
872 fatal("Unexpected bytecode: %s", Bytecodes::name(code));
873 }
874 }
875
876 u2 ConstantPool::uncached_name_and_type_ref_index_at(int cp_index) {
877 if (tag_at(cp_index).has_bootstrap()) {
878 u2 pool_index = bootstrap_name_and_type_ref_index_at(cp_index);
879 assert(tag_at(pool_index).is_name_and_type(), "");
880 return pool_index;
881 }
882 assert(tag_at(cp_index).is_field_or_method(), "Corrupted constant pool");
883 assert(!tag_at(cp_index).has_bootstrap(), "Must be handled above");
884 jint ref_index = *int_at_addr(cp_index);
885 return extract_high_short_from_int(ref_index);
886 }
887
888 u2 ConstantPool::name_and_type_ref_index_at(int index, Bytecodes::Code code) {
889 return uncached_name_and_type_ref_index_at(to_cp_index(index, code));
890 }
891
892 constantTag ConstantPool::tag_ref_at(int which, Bytecodes::Code code) {
893 // which may be either a Constant Pool index or a rewritten index
894 int pool_index = which;
895 assert(cache() != nullptr, "'index' is a rewritten index so this class must have been rewritten");
896 pool_index = to_cp_index(which, code);
897 return tag_at(pool_index);
898 }
899
900 u2 ConstantPool::uncached_klass_ref_index_at(int cp_index) {
901 assert(tag_at(cp_index).is_field_or_method(), "Corrupted constant pool");
902 jint ref_index = *int_at_addr(cp_index);
903 return extract_low_short_from_int(ref_index);
904 }
905
906 u2 ConstantPool::klass_ref_index_at(int index, Bytecodes::Code code) {
907 assert(code != Bytecodes::_invokedynamic,
908 "an invokedynamic instruction does not have a klass");
909 return uncached_klass_ref_index_at(to_cp_index(index, code));
910 }
911
912 void ConstantPool::verify_constant_pool_resolve(const constantPoolHandle& this_cp, Klass* k, TRAPS) {
913 if (!(k->is_instance_klass() || k->is_objArray_klass())) {
914 return; // short cut, typeArray klass is always accessible
915 }
916 Klass* holder = this_cp->pool_holder();
917 LinkResolver::check_klass_accessibility(holder, k, CHECK);
918 }
919
920
921 u2 ConstantPool::name_ref_index_at(int cp_index) {
922 jint ref_index = name_and_type_at(cp_index);
923 return extract_low_short_from_int(ref_index);
924 }
925
926
927 u2 ConstantPool::signature_ref_index_at(int cp_index) {
928 jint ref_index = name_and_type_at(cp_index);
929 return extract_high_short_from_int(ref_index);
930 }
931
932
933 Klass* ConstantPool::klass_ref_at(int which, Bytecodes::Code code, TRAPS) {
934 return klass_at(klass_ref_index_at(which, code), THREAD);
935 }
936
937 Symbol* ConstantPool::klass_name_at(int cp_index) const {
938 return symbol_at(klass_slot_at(cp_index).name_index());
939 }
940
941 Symbol* ConstantPool::klass_ref_at_noresolve(int which, Bytecodes::Code code) {
942 jint ref_index = klass_ref_index_at(which, code);
943 return klass_at_noresolve(ref_index);
944 }
945
946 Symbol* ConstantPool::uncached_klass_ref_at_noresolve(int cp_index) {
947 jint ref_index = uncached_klass_ref_index_at(cp_index);
948 return klass_at_noresolve(ref_index);
949 }
950
951 char* ConstantPool::string_at_noresolve(int cp_index) {
952 return unresolved_string_at(cp_index)->as_C_string();
953 }
954
955 BasicType ConstantPool::basic_type_for_signature_at(int cp_index) const {
956 return Signature::basic_type(symbol_at(cp_index));
957 }
958
959
960 void ConstantPool::resolve_string_constants_impl(const constantPoolHandle& this_cp, TRAPS) {
961 for (int index = 1; index < this_cp->length(); index++) { // Index 0 is unused
962 if (this_cp->tag_at(index).is_string()) {
963 this_cp->string_at(index, CHECK);
964 }
965 }
966 }
967
968 static const char* exception_message(const constantPoolHandle& this_cp, int which, constantTag tag, oop pending_exception) {
969 // Note: caller needs ResourceMark
970
971 // Dig out the detailed message to reuse if possible
972 const char* msg = java_lang_Throwable::message_as_utf8(pending_exception);
973 if (msg != nullptr) {
974 return msg;
975 }
976
977 Symbol* message = nullptr;
978 // Return specific message for the tag
979 switch (tag.value()) {
980 case JVM_CONSTANT_UnresolvedClass:
981 // return the class name in the error message
982 message = this_cp->klass_name_at(which);
983 break;
984 case JVM_CONSTANT_MethodHandle:
985 // return the method handle name in the error message
986 message = this_cp->method_handle_name_ref_at(which);
987 break;
988 case JVM_CONSTANT_MethodType:
989 // return the method type signature in the error message
990 message = this_cp->method_type_signature_at(which);
991 break;
992 case JVM_CONSTANT_Dynamic:
993 // return the name of the condy in the error message
994 message = this_cp->uncached_name_ref_at(which);
995 break;
996 default:
997 ShouldNotReachHere();
998 }
999
1000 return message != nullptr ? message->as_C_string() : nullptr;
1001 }
1002
1003 static void add_resolution_error(JavaThread* current, const constantPoolHandle& this_cp, int which,
1004 constantTag tag, oop pending_exception) {
1005
1006 ResourceMark rm(current);
1007 Symbol* error = pending_exception->klass()->name();
1008 oop cause = java_lang_Throwable::cause(pending_exception);
1009
1010 // Also dig out the exception cause, if present.
1011 Symbol* cause_sym = nullptr;
1012 const char* cause_msg = nullptr;
1013 if (cause != nullptr && cause != pending_exception) {
1014 cause_sym = cause->klass()->name();
1015 cause_msg = java_lang_Throwable::message_as_utf8(cause);
1016 }
1017
1018 const char* message = exception_message(this_cp, which, tag, pending_exception);
1019 SystemDictionary::add_resolution_error(this_cp, which, error, message, cause_sym, cause_msg);
1020 }
1021
1022
1023 void ConstantPool::throw_resolution_error(const constantPoolHandle& this_cp, int which, TRAPS) {
1024 ResourceMark rm(THREAD);
1025 const char* message = nullptr;
1026 Symbol* cause = nullptr;
1027 const char* cause_msg = nullptr;
1028 Symbol* error = SystemDictionary::find_resolution_error(this_cp, which, &message, &cause, &cause_msg);
1029 assert(error != nullptr, "checking");
1030
1031 CLEAR_PENDING_EXCEPTION;
1032 if (message != nullptr) {
1033 if (cause != nullptr) {
1034 Handle h_cause = Exceptions::new_exception(THREAD, cause, cause_msg);
1035 THROW_MSG_CAUSE(error, message, h_cause);
1036 } else {
1037 THROW_MSG(error, message);
1038 }
1039 } else {
1040 if (cause != nullptr) {
1041 Handle h_cause = Exceptions::new_exception(THREAD, cause, cause_msg);
1042 THROW_CAUSE(error, h_cause);
1043 } else {
1044 THROW(error);
1045 }
1046 }
1047 }
1048
1049 // If resolution for Class, Dynamic constant, MethodHandle or MethodType fails, save the
1050 // exception in the resolution error table, so that the same exception is thrown again.
1051 void ConstantPool::save_and_throw_exception(const constantPoolHandle& this_cp, int cp_index,
1052 constantTag tag, TRAPS) {
1053
1054 int error_tag = tag.error_value();
1055
1056 if (!PENDING_EXCEPTION->
1057 is_a(vmClasses::LinkageError_klass())) {
1058 // Just throw the exception and don't prevent these classes from
1059 // being loaded due to virtual machine errors like StackOverflow
1060 // and OutOfMemoryError, etc, or if the thread was hit by stop()
1061 // Needs clarification to section 5.4.3 of the VM spec (see 6308271)
1062 } else if (this_cp->tag_at(cp_index).value() != error_tag) {
1063 add_resolution_error(THREAD, this_cp, cp_index, tag, PENDING_EXCEPTION);
1064 // CAS in the tag. If a thread beat us to registering this error that's fine.
1065 // If another thread resolved the reference, this is a race condition. This
1066 // thread may have had a security manager or something temporary.
1067 // This doesn't deterministically get an error. So why do we save this?
1068 // We save this because jvmti can add classes to the bootclass path after
1069 // this error, so it needs to get the same error if the error is first.
1070 jbyte old_tag = AtomicAccess::cmpxchg((jbyte*)this_cp->tag_addr_at(cp_index),
1071 (jbyte)tag.value(),
1072 (jbyte)error_tag);
1073 if (old_tag != error_tag && old_tag != tag.value()) {
1074 // MethodHandles and MethodType doesn't change to resolved version.
1075 assert(this_cp->tag_at(cp_index).is_klass(), "Wrong tag value");
1076 // Forget the exception and use the resolved class.
1077 CLEAR_PENDING_EXCEPTION;
1078 }
1079 } else {
1080 // some other thread put this in error state
1081 throw_resolution_error(this_cp, cp_index, CHECK);
1082 }
1083 }
1084
1085 constantTag ConstantPool::constant_tag_at(int cp_index) {
1086 constantTag tag = tag_at(cp_index);
1087 if (tag.is_dynamic_constant()) {
1088 BasicType bt = basic_type_for_constant_at(cp_index);
1089 return constantTag(constantTag::type2tag(bt));
1090 }
1091 return tag;
1092 }
1093
1094 BasicType ConstantPool::basic_type_for_constant_at(int cp_index) {
1095 constantTag tag = tag_at(cp_index);
1096 if (tag.is_dynamic_constant() ||
1097 tag.is_dynamic_constant_in_error()) {
1098 // have to look at the signature for this one
1099 Symbol* constant_type = uncached_signature_ref_at(cp_index);
1100 return Signature::basic_type(constant_type);
1101 }
1102 return tag.basic_type();
1103 }
1104
1105 // Called to resolve constants in the constant pool and return an oop.
1106 // Some constant pool entries cache their resolved oop. This is also
1107 // called to create oops from constants to use in arguments for invokedynamic
1108 oop ConstantPool::resolve_constant_at_impl(const constantPoolHandle& this_cp,
1109 int cp_index, int cache_index,
1110 bool* status_return, TRAPS) {
1111 oop result_oop = nullptr;
1112
1113 if (cache_index == _possible_index_sentinel) {
1114 // It is possible that this constant is one which is cached in the objects.
1115 // We'll do a linear search. This should be OK because this usage is rare.
1116 // FIXME: If bootstrap specifiers stress this code, consider putting in
1117 // a reverse index. Binary search over a short array should do it.
1118 assert(cp_index > 0, "valid constant pool index");
1119 cache_index = this_cp->cp_to_object_index(cp_index);
1120 }
1121 assert(cache_index == _no_index_sentinel || cache_index >= 0, "");
1122 assert(cp_index == _no_index_sentinel || cp_index >= 0, "");
1123
1124 if (cache_index >= 0) {
1125 result_oop = this_cp->resolved_reference_at(cache_index);
1126 if (result_oop != nullptr) {
1127 if (result_oop == Universe::the_null_sentinel()) {
1128 DEBUG_ONLY(int temp_index = (cp_index >= 0 ? cp_index : this_cp->object_to_cp_index(cache_index)));
1129 assert(this_cp->tag_at(temp_index).is_dynamic_constant(), "only condy uses the null sentinel");
1130 result_oop = nullptr;
1131 }
1132 if (status_return != nullptr) (*status_return) = true;
1133 return result_oop;
1134 // That was easy...
1135 }
1136 cp_index = this_cp->object_to_cp_index(cache_index);
1137 }
1138
1139 jvalue prim_value; // temp used only in a few cases below
1140
1141 constantTag tag = this_cp->tag_at(cp_index);
1142
1143 if (status_return != nullptr) {
1144 // don't trigger resolution if the constant might need it
1145 switch (tag.value()) {
1146 case JVM_CONSTANT_Class:
1147 assert(this_cp->resolved_klass_at(cp_index) != nullptr, "must be resolved");
1148 break;
1149 case JVM_CONSTANT_String:
1150 case JVM_CONSTANT_Integer:
1151 case JVM_CONSTANT_Float:
1152 case JVM_CONSTANT_Long:
1153 case JVM_CONSTANT_Double:
1154 // these guys trigger OOM at worst
1155 break;
1156 default:
1157 (*status_return) = false;
1158 return nullptr;
1159 }
1160 // from now on there is either success or an OOME
1161 (*status_return) = true;
1162 }
1163
1164 switch (tag.value()) {
1165
1166 case JVM_CONSTANT_UnresolvedClass:
1167 case JVM_CONSTANT_Class:
1168 {
1169 assert(cache_index == _no_index_sentinel, "should not have been set");
1170 Klass* resolved = klass_at_impl(this_cp, cp_index, CHECK_NULL);
1171 // ldc wants the java mirror.
1172 result_oop = resolved->java_mirror();
1173 break;
1174 }
1175
1176 case JVM_CONSTANT_Dynamic:
1177 { PerfTraceTimedEvent timer(ClassLoader::perf_resolve_invokedynamic_time(),
1178 ClassLoader::perf_resolve_invokedynamic_count());
1179
1180 // Resolve the Dynamically-Computed constant to invoke the BSM in order to obtain the resulting oop.
1181 BootstrapInfo bootstrap_specifier(this_cp, cp_index);
1182
1183 // The initial step in resolving an unresolved symbolic reference to a
1184 // dynamically-computed constant is to resolve the symbolic reference to a
1185 // method handle which will be the bootstrap method for the dynamically-computed
1186 // constant. If resolution of the java.lang.invoke.MethodHandle for the bootstrap
1187 // method fails, then a MethodHandleInError is stored at the corresponding
1188 // bootstrap method's CP index for the CONSTANT_MethodHandle_info. No need to
1189 // set a DynamicConstantInError here since any subsequent use of this
1190 // bootstrap method will encounter the resolution of MethodHandleInError.
1191 // Both the first, (resolution of the BSM and its static arguments), and the second tasks,
1192 // (invocation of the BSM), of JVMS Section 5.4.3.6 occur within invoke_bootstrap_method()
1193 // for the bootstrap_specifier created above.
1194 SystemDictionary::invoke_bootstrap_method(bootstrap_specifier, THREAD);
1195 Exceptions::wrap_dynamic_exception(/* is_indy */ false, THREAD);
1196 if (HAS_PENDING_EXCEPTION) {
1197 // Resolution failure of the dynamically-computed constant, save_and_throw_exception
1198 // will check for a LinkageError and store a DynamicConstantInError.
1199 save_and_throw_exception(this_cp, cp_index, tag, CHECK_NULL);
1200 }
1201 result_oop = bootstrap_specifier.resolved_value()();
1202 BasicType type = Signature::basic_type(bootstrap_specifier.signature());
1203 if (!is_reference_type(type)) {
1204 // Make sure the primitive value is properly boxed.
1205 // This is a JDK responsibility.
1206 const char* fail = nullptr;
1207 if (result_oop == nullptr) {
1208 fail = "null result instead of box";
1209 } else if (!is_java_primitive(type)) {
1210 // FIXME: support value types via unboxing
1211 fail = "can only handle references and primitives";
1212 } else if (!java_lang_boxing_object::is_instance(result_oop, type)) {
1213 fail = "primitive is not properly boxed";
1214 }
1215 if (fail != nullptr) {
1216 // Since this exception is not a LinkageError, throw exception
1217 // but do not save a DynamicInError resolution result.
1218 // See section 5.4.3 of the VM spec.
1219 THROW_MSG_NULL(vmSymbols::java_lang_InternalError(), fail);
1220 }
1221 }
1222
1223 LogTarget(Debug, methodhandles, condy) lt_condy;
1224 if (lt_condy.is_enabled()) {
1225 LogStream ls(lt_condy);
1226 bootstrap_specifier.print_msg_on(&ls, "resolve_constant_at_impl");
1227 }
1228 break;
1229 }
1230
1231 case JVM_CONSTANT_String:
1232 assert(cache_index != _no_index_sentinel, "should have been set");
1233 result_oop = string_at_impl(this_cp, cp_index, cache_index, CHECK_NULL);
1234 break;
1235
1236 case JVM_CONSTANT_MethodHandle:
1237 { PerfTraceTimedEvent timer(ClassLoader::perf_resolve_method_handle_time(),
1238 ClassLoader::perf_resolve_method_handle_count());
1239
1240 int ref_kind = this_cp->method_handle_ref_kind_at(cp_index);
1241 int callee_index = this_cp->method_handle_klass_index_at(cp_index);
1242 Symbol* name = this_cp->method_handle_name_ref_at(cp_index);
1243 Symbol* signature = this_cp->method_handle_signature_ref_at(cp_index);
1244 constantTag m_tag = this_cp->tag_at(this_cp->method_handle_index_at(cp_index));
1245 { ResourceMark rm(THREAD);
1246 log_debug(class, resolve)("resolve JVM_CONSTANT_MethodHandle:%d [%d/%d/%d] %s.%s",
1247 ref_kind, cp_index, this_cp->method_handle_index_at(cp_index),
1248 callee_index, name->as_C_string(), signature->as_C_string());
1249 }
1250
1251 Klass* callee = klass_at_impl(this_cp, callee_index, THREAD);
1252 if (HAS_PENDING_EXCEPTION) {
1253 save_and_throw_exception(this_cp, cp_index, tag, CHECK_NULL);
1254 }
1255
1256 // Check constant pool method consistency
1257 if ((callee->is_interface() && m_tag.is_method()) ||
1258 (!callee->is_interface() && m_tag.is_interface_method())) {
1259 ResourceMark rm(THREAD);
1260 stringStream ss;
1261 ss.print("Inconsistent constant pool data in classfile for class %s. "
1262 "Method '", callee->name()->as_C_string());
1263 signature->print_as_signature_external_return_type(&ss);
1264 ss.print(" %s(", name->as_C_string());
1265 signature->print_as_signature_external_parameters(&ss);
1266 ss.print(")' at index %d is %s and should be %s",
1267 cp_index,
1268 callee->is_interface() ? "CONSTANT_MethodRef" : "CONSTANT_InterfaceMethodRef",
1269 callee->is_interface() ? "CONSTANT_InterfaceMethodRef" : "CONSTANT_MethodRef");
1270 // Names are all known to be < 64k so we know this formatted message is not excessively large.
1271 Exceptions::fthrow(THREAD_AND_LOCATION, vmSymbols::java_lang_IncompatibleClassChangeError(), "%s", ss.as_string());
1272 save_and_throw_exception(this_cp, cp_index, tag, CHECK_NULL);
1273 }
1274
1275 Klass* klass = this_cp->pool_holder();
1276 HandleMark hm(THREAD);
1277 Handle value = SystemDictionary::link_method_handle_constant(klass, ref_kind,
1278 callee, name, signature,
1279 THREAD);
1280 if (HAS_PENDING_EXCEPTION) {
1281 save_and_throw_exception(this_cp, cp_index, tag, CHECK_NULL);
1282 }
1283 result_oop = value();
1284 break;
1285 }
1286
1287 case JVM_CONSTANT_MethodType:
1288 { PerfTraceTimedEvent timer(ClassLoader::perf_resolve_method_type_time(),
1289 ClassLoader::perf_resolve_method_type_count());
1290
1291 Symbol* signature = this_cp->method_type_signature_at(cp_index);
1292 { ResourceMark rm(THREAD);
1293 log_debug(class, resolve)("resolve JVM_CONSTANT_MethodType [%d/%d] %s",
1294 cp_index, this_cp->method_type_index_at(cp_index),
1295 signature->as_C_string());
1296 }
1297 Klass* klass = this_cp->pool_holder();
1298 HandleMark hm(THREAD);
1299 Handle value = SystemDictionary::find_method_handle_type(signature, klass, THREAD);
1300 result_oop = value();
1301 if (HAS_PENDING_EXCEPTION) {
1302 save_and_throw_exception(this_cp, cp_index, tag, CHECK_NULL);
1303 }
1304 break;
1305 }
1306
1307 case JVM_CONSTANT_Integer:
1308 assert(cache_index == _no_index_sentinel, "should not have been set");
1309 prim_value.i = this_cp->int_at(cp_index);
1310 result_oop = java_lang_boxing_object::create(T_INT, &prim_value, CHECK_NULL);
1311 break;
1312
1313 case JVM_CONSTANT_Float:
1314 assert(cache_index == _no_index_sentinel, "should not have been set");
1315 prim_value.f = this_cp->float_at(cp_index);
1316 result_oop = java_lang_boxing_object::create(T_FLOAT, &prim_value, CHECK_NULL);
1317 break;
1318
1319 case JVM_CONSTANT_Long:
1320 assert(cache_index == _no_index_sentinel, "should not have been set");
1321 prim_value.j = this_cp->long_at(cp_index);
1322 result_oop = java_lang_boxing_object::create(T_LONG, &prim_value, CHECK_NULL);
1323 break;
1324
1325 case JVM_CONSTANT_Double:
1326 assert(cache_index == _no_index_sentinel, "should not have been set");
1327 prim_value.d = this_cp->double_at(cp_index);
1328 result_oop = java_lang_boxing_object::create(T_DOUBLE, &prim_value, CHECK_NULL);
1329 break;
1330
1331 case JVM_CONSTANT_UnresolvedClassInError:
1332 case JVM_CONSTANT_DynamicInError:
1333 case JVM_CONSTANT_MethodHandleInError:
1334 case JVM_CONSTANT_MethodTypeInError:
1335 throw_resolution_error(this_cp, cp_index, CHECK_NULL);
1336 break;
1337
1338 default:
1339 fatal("unexpected constant tag at CP %p[%d/%d] = %d", this_cp(), cp_index, cache_index, tag.value());
1340 break;
1341 }
1342
1343 if (cache_index >= 0) {
1344 // Benign race condition: resolved_references may already be filled in.
1345 // The important thing here is that all threads pick up the same result.
1346 // It doesn't matter which racing thread wins, as long as only one
1347 // result is used by all threads, and all future queries.
1348 oop new_result = (result_oop == nullptr ? Universe::the_null_sentinel() : result_oop);
1349 oop old_result = this_cp->set_resolved_reference_at(cache_index, new_result);
1350 if (old_result == nullptr) {
1351 return result_oop; // was installed
1352 } else {
1353 // Return the winning thread's result. This can be different than
1354 // the result here for MethodHandles.
1355 if (old_result == Universe::the_null_sentinel())
1356 old_result = nullptr;
1357 return old_result;
1358 }
1359 } else {
1360 assert(result_oop != Universe::the_null_sentinel(), "");
1361 return result_oop;
1362 }
1363 }
1364
1365 oop ConstantPool::uncached_string_at(int cp_index, TRAPS) {
1366 Symbol* sym = unresolved_string_at(cp_index);
1367 oop str = StringTable::intern(sym, CHECK_(nullptr));
1368 assert(java_lang_String::is_instance(str), "must be string");
1369 return str;
1370 }
1371
1372 void ConstantPool::copy_bootstrap_arguments_at_impl(const constantPoolHandle& this_cp, int cp_index,
1373 int start_arg, int end_arg,
1374 objArrayHandle info, int pos,
1375 bool must_resolve, Handle if_not_available,
1376 TRAPS) {
1377 int limit = pos + end_arg - start_arg;
1378 // checks: cp_index in range [0..this_cp->length),
1379 // tag at cp_index, start..end in range [0..this_cp->bootstrap_argument_count],
1380 // info array non-null, pos..limit in [0..info.length]
1381 if ((0 >= cp_index || cp_index >= this_cp->length()) ||
1382 !(this_cp->tag_at(cp_index).is_invoke_dynamic() ||
1383 this_cp->tag_at(cp_index).is_dynamic_constant()) ||
1384 (0 > start_arg || start_arg > end_arg) ||
1385 (end_arg > this_cp->bootstrap_argument_count_at(cp_index)) ||
1386 (0 > pos || pos > limit) ||
1387 (info.is_null() || limit > info->length())) {
1388 // An index or something else went wrong; throw an error.
1389 // Since this is an internal API, we don't expect this,
1390 // so we don't bother to craft a nice message.
1391 THROW_MSG(vmSymbols::java_lang_LinkageError(), "bad BSM argument access");
1392 }
1393 // now we can loop safely
1394 int info_i = pos;
1395 for (int i = start_arg; i < end_arg; i++) {
1396 int arg_index = this_cp->bootstrap_argument_index_at(cp_index, i);
1397 oop arg_oop;
1398 if (must_resolve) {
1399 arg_oop = this_cp->resolve_possibly_cached_constant_at(arg_index, CHECK);
1400 } else {
1401 bool found_it = false;
1402 arg_oop = this_cp->find_cached_constant_at(arg_index, found_it, CHECK);
1403 if (!found_it) arg_oop = if_not_available();
1404 }
1405 info->obj_at_put(info_i++, arg_oop);
1406 }
1407 }
1408
1409 oop ConstantPool::string_at_impl(const constantPoolHandle& this_cp, int cp_index, int obj_index, TRAPS) {
1410 // If the string has already been interned, this entry will be non-null
1411 oop str = this_cp->resolved_reference_at(obj_index);
1412 assert(str != Universe::the_null_sentinel(), "");
1413 if (str != nullptr) return str;
1414 Symbol* sym = this_cp->unresolved_string_at(cp_index);
1415 str = StringTable::intern(sym, CHECK_(nullptr));
1416 this_cp->string_at_put(obj_index, str);
1417 assert(java_lang_String::is_instance(str), "must be string");
1418 return str;
1419 }
1420
1421
1422 bool ConstantPool::klass_name_at_matches(const InstanceKlass* k, int cp_index) {
1423 // Names are interned, so we can compare Symbol*s directly
1424 Symbol* cp_name = klass_name_at(cp_index);
1425 return (cp_name == k->name());
1426 }
1427
1428
1429 // Iterate over symbols and decrement ones which are Symbol*s
1430 // This is done during GC.
1431 // Only decrement the UTF8 symbols. Strings point to
1432 // these symbols but didn't increment the reference count.
1433 void ConstantPool::unreference_symbols() {
1434 for (int index = 1; index < length(); index++) { // Index 0 is unused
1435 constantTag tag = tag_at(index);
1436 if (tag.is_symbol()) {
1437 symbol_at(index)->decrement_refcount();
1438 }
1439 }
1440 }
1441
1442
1443 // Compare this constant pool's entry at index1 to the constant pool
1444 // cp2's entry at index2.
1445 bool ConstantPool::compare_entry_to(int index1, const constantPoolHandle& cp2,
1446 int index2) {
1447
1448 // The error tags are equivalent to non-error tags when comparing
1449 jbyte t1 = tag_at(index1).non_error_value();
1450 jbyte t2 = cp2->tag_at(index2).non_error_value();
1451
1452 // Some classes are pre-resolved (like Throwable) which may lead to
1453 // consider it as a different entry. We then revert them back temporarily
1454 // to ensure proper comparison.
1455 if (t1 == JVM_CONSTANT_Class) {
1456 t1 = JVM_CONSTANT_UnresolvedClass;
1457 }
1458 if (t2 == JVM_CONSTANT_Class) {
1459 t2 = JVM_CONSTANT_UnresolvedClass;
1460 }
1461
1462 if (t1 != t2) {
1463 // Not the same entry type so there is nothing else to check. Note
1464 // that this style of checking will consider resolved/unresolved
1465 // class pairs as different.
1466 // From the ConstantPool* API point of view, this is correct
1467 // behavior. See VM_RedefineClasses::merge_constant_pools() to see how this
1468 // plays out in the context of ConstantPool* merging.
1469 return false;
1470 }
1471
1472 switch (t1) {
1473 case JVM_CONSTANT_ClassIndex:
1474 {
1475 int recur1 = klass_index_at(index1);
1476 int recur2 = cp2->klass_index_at(index2);
1477 if (compare_entry_to(recur1, cp2, recur2)) {
1478 return true;
1479 }
1480 } break;
1481
1482 case JVM_CONSTANT_Double:
1483 {
1484 jdouble d1 = double_at(index1);
1485 jdouble d2 = cp2->double_at(index2);
1486 if (d1 == d2) {
1487 return true;
1488 }
1489 } break;
1490
1491 case JVM_CONSTANT_Fieldref:
1492 case JVM_CONSTANT_InterfaceMethodref:
1493 case JVM_CONSTANT_Methodref:
1494 {
1495 int recur1 = uncached_klass_ref_index_at(index1);
1496 int recur2 = cp2->uncached_klass_ref_index_at(index2);
1497 bool match = compare_entry_to(recur1, cp2, recur2);
1498 if (match) {
1499 recur1 = uncached_name_and_type_ref_index_at(index1);
1500 recur2 = cp2->uncached_name_and_type_ref_index_at(index2);
1501 if (compare_entry_to(recur1, cp2, recur2)) {
1502 return true;
1503 }
1504 }
1505 } break;
1506
1507 case JVM_CONSTANT_Float:
1508 {
1509 jfloat f1 = float_at(index1);
1510 jfloat f2 = cp2->float_at(index2);
1511 if (f1 == f2) {
1512 return true;
1513 }
1514 } break;
1515
1516 case JVM_CONSTANT_Integer:
1517 {
1518 jint i1 = int_at(index1);
1519 jint i2 = cp2->int_at(index2);
1520 if (i1 == i2) {
1521 return true;
1522 }
1523 } break;
1524
1525 case JVM_CONSTANT_Long:
1526 {
1527 jlong l1 = long_at(index1);
1528 jlong l2 = cp2->long_at(index2);
1529 if (l1 == l2) {
1530 return true;
1531 }
1532 } break;
1533
1534 case JVM_CONSTANT_NameAndType:
1535 {
1536 int recur1 = name_ref_index_at(index1);
1537 int recur2 = cp2->name_ref_index_at(index2);
1538 if (compare_entry_to(recur1, cp2, recur2)) {
1539 recur1 = signature_ref_index_at(index1);
1540 recur2 = cp2->signature_ref_index_at(index2);
1541 if (compare_entry_to(recur1, cp2, recur2)) {
1542 return true;
1543 }
1544 }
1545 } break;
1546
1547 case JVM_CONSTANT_StringIndex:
1548 {
1549 int recur1 = string_index_at(index1);
1550 int recur2 = cp2->string_index_at(index2);
1551 if (compare_entry_to(recur1, cp2, recur2)) {
1552 return true;
1553 }
1554 } break;
1555
1556 case JVM_CONSTANT_UnresolvedClass:
1557 {
1558 Symbol* k1 = klass_name_at(index1);
1559 Symbol* k2 = cp2->klass_name_at(index2);
1560 if (k1 == k2) {
1561 return true;
1562 }
1563 } break;
1564
1565 case JVM_CONSTANT_MethodType:
1566 {
1567 int k1 = method_type_index_at(index1);
1568 int k2 = cp2->method_type_index_at(index2);
1569 if (compare_entry_to(k1, cp2, k2)) {
1570 return true;
1571 }
1572 } break;
1573
1574 case JVM_CONSTANT_MethodHandle:
1575 {
1576 int k1 = method_handle_ref_kind_at(index1);
1577 int k2 = cp2->method_handle_ref_kind_at(index2);
1578 if (k1 == k2) {
1579 int i1 = method_handle_index_at(index1);
1580 int i2 = cp2->method_handle_index_at(index2);
1581 if (compare_entry_to(i1, cp2, i2)) {
1582 return true;
1583 }
1584 }
1585 } break;
1586
1587 case JVM_CONSTANT_Dynamic:
1588 {
1589 int k1 = bootstrap_name_and_type_ref_index_at(index1);
1590 int k2 = cp2->bootstrap_name_and_type_ref_index_at(index2);
1591 int i1 = bootstrap_methods_attribute_index(index1);
1592 int i2 = cp2->bootstrap_methods_attribute_index(index2);
1593 bool match_entry = compare_entry_to(k1, cp2, k2);
1594 bool match_operand = compare_operand_to(i1, cp2, i2);
1595 return (match_entry && match_operand);
1596 } break;
1597
1598 case JVM_CONSTANT_InvokeDynamic:
1599 {
1600 int k1 = bootstrap_name_and_type_ref_index_at(index1);
1601 int k2 = cp2->bootstrap_name_and_type_ref_index_at(index2);
1602 int i1 = bootstrap_methods_attribute_index(index1);
1603 int i2 = cp2->bootstrap_methods_attribute_index(index2);
1604 bool match_entry = compare_entry_to(k1, cp2, k2);
1605 bool match_operand = compare_operand_to(i1, cp2, i2);
1606 return (match_entry && match_operand);
1607 } break;
1608
1609 case JVM_CONSTANT_String:
1610 {
1611 Symbol* s1 = unresolved_string_at(index1);
1612 Symbol* s2 = cp2->unresolved_string_at(index2);
1613 if (s1 == s2) {
1614 return true;
1615 }
1616 } break;
1617
1618 case JVM_CONSTANT_Utf8:
1619 {
1620 Symbol* s1 = symbol_at(index1);
1621 Symbol* s2 = cp2->symbol_at(index2);
1622 if (s1 == s2) {
1623 return true;
1624 }
1625 } break;
1626
1627 // Invalid is used as the tag for the second constant pool entry
1628 // occupied by JVM_CONSTANT_Double or JVM_CONSTANT_Long. It should
1629 // not be seen by itself.
1630 case JVM_CONSTANT_Invalid: // fall through
1631
1632 default:
1633 ShouldNotReachHere();
1634 break;
1635 }
1636
1637 return false;
1638 } // end compare_entry_to()
1639
1640
1641 // Resize the operands array with delta_len and delta_size.
1642 // Used in RedefineClasses for CP merge.
1643 void ConstantPool::resize_operands(int delta_len, int delta_size, TRAPS) {
1644 int old_len = operand_array_length(operands());
1645 int new_len = old_len + delta_len;
1646 int min_len = (delta_len > 0) ? old_len : new_len;
1647
1648 int old_size = operands()->length();
1649 int new_size = old_size + delta_size;
1650 int min_size = (delta_size > 0) ? old_size : new_size;
1651
1652 ClassLoaderData* loader_data = pool_holder()->class_loader_data();
1653 Array<u2>* new_ops = MetadataFactory::new_array<u2>(loader_data, new_size, CHECK);
1654
1655 // Set index in the resized array for existing elements only
1656 for (int idx = 0; idx < min_len; idx++) {
1657 int offset = operand_offset_at(idx); // offset in original array
1658 operand_offset_at_put(new_ops, idx, offset + 2*delta_len); // offset in resized array
1659 }
1660 // Copy the bootstrap specifiers only
1661 Copy::conjoint_memory_atomic(operands()->adr_at(2*old_len),
1662 new_ops->adr_at(2*new_len),
1663 (min_size - 2*min_len) * sizeof(u2));
1664 // Explicitly deallocate old operands array.
1665 // Note, it is not needed for 7u backport.
1666 if ( operands() != nullptr) { // the safety check
1667 MetadataFactory::free_array<u2>(loader_data, operands());
1668 }
1669 set_operands(new_ops);
1670 } // end resize_operands()
1671
1672
1673 // Extend the operands array with the length and size of the ext_cp operands.
1674 // Used in RedefineClasses for CP merge.
1675 void ConstantPool::extend_operands(const constantPoolHandle& ext_cp, TRAPS) {
1676 int delta_len = operand_array_length(ext_cp->operands());
1677 if (delta_len == 0) {
1678 return; // nothing to do
1679 }
1680 int delta_size = ext_cp->operands()->length();
1681
1682 assert(delta_len > 0 && delta_size > 0, "extended operands array must be bigger");
1683
1684 if (operand_array_length(operands()) == 0) {
1685 ClassLoaderData* loader_data = pool_holder()->class_loader_data();
1686 Array<u2>* new_ops = MetadataFactory::new_array<u2>(loader_data, delta_size, CHECK);
1687 // The first element index defines the offset of second part
1688 operand_offset_at_put(new_ops, 0, 2*delta_len); // offset in new array
1689 set_operands(new_ops);
1690 } else {
1691 resize_operands(delta_len, delta_size, CHECK);
1692 }
1693
1694 } // end extend_operands()
1695
1696
1697 // Shrink the operands array to a smaller array with new_len length.
1698 // Used in RedefineClasses for CP merge.
1699 void ConstantPool::shrink_operands(int new_len, TRAPS) {
1700 int old_len = operand_array_length(operands());
1701 if (new_len == old_len) {
1702 return; // nothing to do
1703 }
1704 assert(new_len < old_len, "shrunken operands array must be smaller");
1705
1706 int free_base = operand_next_offset_at(new_len - 1);
1707 int delta_len = new_len - old_len;
1708 int delta_size = 2*delta_len + free_base - operands()->length();
1709
1710 resize_operands(delta_len, delta_size, CHECK);
1711
1712 } // end shrink_operands()
1713
1714
1715 void ConstantPool::copy_operands(const constantPoolHandle& from_cp,
1716 const constantPoolHandle& to_cp,
1717 TRAPS) {
1718
1719 int from_oplen = operand_array_length(from_cp->operands());
1720 int old_oplen = operand_array_length(to_cp->operands());
1721 if (from_oplen != 0) {
1722 ClassLoaderData* loader_data = to_cp->pool_holder()->class_loader_data();
1723 // append my operands to the target's operands array
1724 if (old_oplen == 0) {
1725 // Can't just reuse from_cp's operand list because of deallocation issues
1726 int len = from_cp->operands()->length();
1727 Array<u2>* new_ops = MetadataFactory::new_array<u2>(loader_data, len, CHECK);
1728 Copy::conjoint_memory_atomic(
1729 from_cp->operands()->adr_at(0), new_ops->adr_at(0), len * sizeof(u2));
1730 to_cp->set_operands(new_ops);
1731 } else {
1732 int old_len = to_cp->operands()->length();
1733 int from_len = from_cp->operands()->length();
1734 int old_off = old_oplen * sizeof(u2);
1735 int from_off = from_oplen * sizeof(u2);
1736 // Use the metaspace for the destination constant pool
1737 Array<u2>* new_operands = MetadataFactory::new_array<u2>(loader_data, old_len + from_len, CHECK);
1738 int fillp = 0, len = 0;
1739 // first part of dest
1740 Copy::conjoint_memory_atomic(to_cp->operands()->adr_at(0),
1741 new_operands->adr_at(fillp),
1742 (len = old_off) * sizeof(u2));
1743 fillp += len;
1744 // first part of src
1745 Copy::conjoint_memory_atomic(from_cp->operands()->adr_at(0),
1746 new_operands->adr_at(fillp),
1747 (len = from_off) * sizeof(u2));
1748 fillp += len;
1749 // second part of dest
1750 Copy::conjoint_memory_atomic(to_cp->operands()->adr_at(old_off),
1751 new_operands->adr_at(fillp),
1752 (len = old_len - old_off) * sizeof(u2));
1753 fillp += len;
1754 // second part of src
1755 Copy::conjoint_memory_atomic(from_cp->operands()->adr_at(from_off),
1756 new_operands->adr_at(fillp),
1757 (len = from_len - from_off) * sizeof(u2));
1758 fillp += len;
1759 assert(fillp == new_operands->length(), "");
1760
1761 // Adjust indexes in the first part of the copied operands array.
1762 for (int j = 0; j < from_oplen; j++) {
1763 int offset = operand_offset_at(new_operands, old_oplen + j);
1764 assert(offset == operand_offset_at(from_cp->operands(), j), "correct copy");
1765 offset += old_len; // every new tuple is preceded by old_len extra u2's
1766 operand_offset_at_put(new_operands, old_oplen + j, offset);
1767 }
1768
1769 // replace target operands array with combined array
1770 to_cp->set_operands(new_operands);
1771 }
1772 }
1773 } // end copy_operands()
1774
1775
1776 // Copy this constant pool's entries at start_i to end_i (inclusive)
1777 // to the constant pool to_cp's entries starting at to_i. A total of
1778 // (end_i - start_i) + 1 entries are copied.
1779 void ConstantPool::copy_cp_to_impl(const constantPoolHandle& from_cp, int start_i, int end_i,
1780 const constantPoolHandle& to_cp, int to_i, TRAPS) {
1781
1782
1783 int dest_cpi = to_i; // leave original alone for debug purposes
1784
1785 for (int src_cpi = start_i; src_cpi <= end_i; /* see loop bottom */ ) {
1786 copy_entry_to(from_cp, src_cpi, to_cp, dest_cpi);
1787
1788 switch (from_cp->tag_at(src_cpi).value()) {
1789 case JVM_CONSTANT_Double:
1790 case JVM_CONSTANT_Long:
1791 // double and long take two constant pool entries
1792 src_cpi += 2;
1793 dest_cpi += 2;
1794 break;
1795
1796 default:
1797 // all others take one constant pool entry
1798 src_cpi++;
1799 dest_cpi++;
1800 break;
1801 }
1802 }
1803 copy_operands(from_cp, to_cp, CHECK);
1804
1805 } // end copy_cp_to_impl()
1806
1807
1808 // Copy this constant pool's entry at from_i to the constant pool
1809 // to_cp's entry at to_i.
1810 void ConstantPool::copy_entry_to(const constantPoolHandle& from_cp, int from_i,
1811 const constantPoolHandle& to_cp, int to_i) {
1812
1813 int tag = from_cp->tag_at(from_i).value();
1814 switch (tag) {
1815 case JVM_CONSTANT_ClassIndex:
1816 {
1817 jint ki = from_cp->klass_index_at(from_i);
1818 to_cp->klass_index_at_put(to_i, ki);
1819 } break;
1820
1821 case JVM_CONSTANT_Double:
1822 {
1823 jdouble d = from_cp->double_at(from_i);
1824 to_cp->double_at_put(to_i, d);
1825 // double takes two constant pool entries so init second entry's tag
1826 to_cp->tag_at_put(to_i + 1, JVM_CONSTANT_Invalid);
1827 } break;
1828
1829 case JVM_CONSTANT_Fieldref:
1830 {
1831 int class_index = from_cp->uncached_klass_ref_index_at(from_i);
1832 int name_and_type_index = from_cp->uncached_name_and_type_ref_index_at(from_i);
1833 to_cp->field_at_put(to_i, class_index, name_and_type_index);
1834 } break;
1835
1836 case JVM_CONSTANT_Float:
1837 {
1838 jfloat f = from_cp->float_at(from_i);
1839 to_cp->float_at_put(to_i, f);
1840 } break;
1841
1842 case JVM_CONSTANT_Integer:
1843 {
1844 jint i = from_cp->int_at(from_i);
1845 to_cp->int_at_put(to_i, i);
1846 } break;
1847
1848 case JVM_CONSTANT_InterfaceMethodref:
1849 {
1850 int class_index = from_cp->uncached_klass_ref_index_at(from_i);
1851 int name_and_type_index = from_cp->uncached_name_and_type_ref_index_at(from_i);
1852 to_cp->interface_method_at_put(to_i, class_index, name_and_type_index);
1853 } break;
1854
1855 case JVM_CONSTANT_Long:
1856 {
1857 jlong l = from_cp->long_at(from_i);
1858 to_cp->long_at_put(to_i, l);
1859 // long takes two constant pool entries so init second entry's tag
1860 to_cp->tag_at_put(to_i + 1, JVM_CONSTANT_Invalid);
1861 } break;
1862
1863 case JVM_CONSTANT_Methodref:
1864 {
1865 int class_index = from_cp->uncached_klass_ref_index_at(from_i);
1866 int name_and_type_index = from_cp->uncached_name_and_type_ref_index_at(from_i);
1867 to_cp->method_at_put(to_i, class_index, name_and_type_index);
1868 } break;
1869
1870 case JVM_CONSTANT_NameAndType:
1871 {
1872 int name_ref_index = from_cp->name_ref_index_at(from_i);
1873 int signature_ref_index = from_cp->signature_ref_index_at(from_i);
1874 to_cp->name_and_type_at_put(to_i, name_ref_index, signature_ref_index);
1875 } break;
1876
1877 case JVM_CONSTANT_StringIndex:
1878 {
1879 jint si = from_cp->string_index_at(from_i);
1880 to_cp->string_index_at_put(to_i, si);
1881 } break;
1882
1883 case JVM_CONSTANT_Class:
1884 case JVM_CONSTANT_UnresolvedClass:
1885 case JVM_CONSTANT_UnresolvedClassInError:
1886 {
1887 // Revert to JVM_CONSTANT_ClassIndex
1888 int name_index = from_cp->klass_slot_at(from_i).name_index();
1889 assert(from_cp->tag_at(name_index).is_symbol(), "sanity");
1890 to_cp->klass_index_at_put(to_i, name_index);
1891 } break;
1892
1893 case JVM_CONSTANT_String:
1894 {
1895 Symbol* s = from_cp->unresolved_string_at(from_i);
1896 to_cp->unresolved_string_at_put(to_i, s);
1897 } break;
1898
1899 case JVM_CONSTANT_Utf8:
1900 {
1901 Symbol* s = from_cp->symbol_at(from_i);
1902 // Need to increase refcount, the old one will be thrown away and deferenced
1903 s->increment_refcount();
1904 to_cp->symbol_at_put(to_i, s);
1905 } break;
1906
1907 case JVM_CONSTANT_MethodType:
1908 case JVM_CONSTANT_MethodTypeInError:
1909 {
1910 jint k = from_cp->method_type_index_at(from_i);
1911 to_cp->method_type_index_at_put(to_i, k);
1912 } break;
1913
1914 case JVM_CONSTANT_MethodHandle:
1915 case JVM_CONSTANT_MethodHandleInError:
1916 {
1917 int k1 = from_cp->method_handle_ref_kind_at(from_i);
1918 int k2 = from_cp->method_handle_index_at(from_i);
1919 to_cp->method_handle_index_at_put(to_i, k1, k2);
1920 } break;
1921
1922 case JVM_CONSTANT_Dynamic:
1923 case JVM_CONSTANT_DynamicInError:
1924 {
1925 int k1 = from_cp->bootstrap_methods_attribute_index(from_i);
1926 int k2 = from_cp->bootstrap_name_and_type_ref_index_at(from_i);
1927 k1 += operand_array_length(to_cp->operands()); // to_cp might already have operands
1928 to_cp->dynamic_constant_at_put(to_i, k1, k2);
1929 } break;
1930
1931 case JVM_CONSTANT_InvokeDynamic:
1932 {
1933 int k1 = from_cp->bootstrap_methods_attribute_index(from_i);
1934 int k2 = from_cp->bootstrap_name_and_type_ref_index_at(from_i);
1935 k1 += operand_array_length(to_cp->operands()); // to_cp might already have operands
1936 to_cp->invoke_dynamic_at_put(to_i, k1, k2);
1937 } break;
1938
1939 // Invalid is used as the tag for the second constant pool entry
1940 // occupied by JVM_CONSTANT_Double or JVM_CONSTANT_Long. It should
1941 // not be seen by itself.
1942 case JVM_CONSTANT_Invalid: // fall through
1943
1944 default:
1945 {
1946 ShouldNotReachHere();
1947 } break;
1948 }
1949 } // end copy_entry_to()
1950
1951 // Search constant pool search_cp for an entry that matches this
1952 // constant pool's entry at pattern_i. Returns the index of a
1953 // matching entry or zero (0) if there is no matching entry.
1954 int ConstantPool::find_matching_entry(int pattern_i,
1955 const constantPoolHandle& search_cp) {
1956
1957 // index zero (0) is not used
1958 for (int i = 1; i < search_cp->length(); i++) {
1959 bool found = compare_entry_to(pattern_i, search_cp, i);
1960 if (found) {
1961 return i;
1962 }
1963 }
1964
1965 return 0; // entry not found; return unused index zero (0)
1966 } // end find_matching_entry()
1967
1968
1969 // Compare this constant pool's bootstrap specifier at idx1 to the constant pool
1970 // cp2's bootstrap specifier at idx2.
1971 bool ConstantPool::compare_operand_to(int idx1, const constantPoolHandle& cp2, int idx2) {
1972 BSMAttributeEntry* e1 = bsm_attribute_entry(idx1);
1973 BSMAttributeEntry* e2 = cp2->bsm_attribute_entry(idx2);
1974 int k1 = e1->bootstrap_method_index();
1975 int k2 = e2->bootstrap_method_index();
1976 bool match = compare_entry_to(k1, cp2, k2);
1977
1978 if (!match) {
1979 return false;
1980 }
1981 int argc = e1->argument_count();
1982 if (argc == e2->argument_count()) {
1983 for (int j = 0; j < argc; j++) {
1984 k1 = e1->argument_index(j);
1985 k2 = e2->argument_index(j);
1986 match = compare_entry_to(k1, cp2, k2);
1987 if (!match) {
1988 return false;
1989 }
1990 }
1991 return true; // got through loop; all elements equal
1992 }
1993 return false;
1994 } // end compare_operand_to()
1995
1996 // Search constant pool search_cp for a bootstrap specifier that matches
1997 // this constant pool's bootstrap specifier data at pattern_i index.
1998 // Return the index of a matching bootstrap attribute record or (-1) if there is no match.
1999 int ConstantPool::find_matching_operand(int pattern_i,
2000 const constantPoolHandle& search_cp, int search_len) {
2001 for (int i = 0; i < search_len; i++) {
2002 bool found = compare_operand_to(pattern_i, search_cp, i);
2003 if (found) {
2004 return i;
2005 }
2006 }
2007 return -1; // bootstrap specifier data not found; return unused index (-1)
2008 } // end find_matching_operand()
2009
2010
2011 #ifndef PRODUCT
2012
2013 const char* ConstantPool::printable_name_at(int cp_index) {
2014
2015 constantTag tag = tag_at(cp_index);
2016
2017 if (tag.is_string()) {
2018 return string_at_noresolve(cp_index);
2019 } else if (tag.is_klass() || tag.is_unresolved_klass()) {
2020 return klass_name_at(cp_index)->as_C_string();
2021 } else if (tag.is_symbol()) {
2022 return symbol_at(cp_index)->as_C_string();
2023 }
2024 return "";
2025 }
2026
2027 #endif // PRODUCT
2028
2029
2030 // Returns size of constant pool entry.
2031 jint ConstantPool::cpool_entry_size(jint idx) {
2032 switch(tag_at(idx).value()) {
2033 case JVM_CONSTANT_Invalid:
2034 case JVM_CONSTANT_Unicode:
2035 return 1;
2036
2037 case JVM_CONSTANT_Utf8:
2038 return 3 + symbol_at(idx)->utf8_length();
2039
2040 case JVM_CONSTANT_Class:
2041 case JVM_CONSTANT_String:
2042 case JVM_CONSTANT_ClassIndex:
2043 case JVM_CONSTANT_UnresolvedClass:
2044 case JVM_CONSTANT_UnresolvedClassInError:
2045 case JVM_CONSTANT_StringIndex:
2046 case JVM_CONSTANT_MethodType:
2047 case JVM_CONSTANT_MethodTypeInError:
2048 return 3;
2049
2050 case JVM_CONSTANT_MethodHandle:
2051 case JVM_CONSTANT_MethodHandleInError:
2052 return 4; //tag, ref_kind, ref_index
2053
2054 case JVM_CONSTANT_Integer:
2055 case JVM_CONSTANT_Float:
2056 case JVM_CONSTANT_Fieldref:
2057 case JVM_CONSTANT_Methodref:
2058 case JVM_CONSTANT_InterfaceMethodref:
2059 case JVM_CONSTANT_NameAndType:
2060 return 5;
2061
2062 case JVM_CONSTANT_Dynamic:
2063 case JVM_CONSTANT_DynamicInError:
2064 case JVM_CONSTANT_InvokeDynamic:
2065 // u1 tag, u2 bsm, u2 nt
2066 return 5;
2067
2068 case JVM_CONSTANT_Long:
2069 case JVM_CONSTANT_Double:
2070 return 9;
2071 }
2072 assert(false, "cpool_entry_size: Invalid constant pool entry tag");
2073 return 1;
2074 } /* end cpool_entry_size */
2075
2076
2077 // SymbolHash is used to find a constant pool index from a string.
2078 // This function fills in SymbolHashs, one for utf8s and one for
2079 // class names, returns size of the cpool raw bytes.
2080 jint ConstantPool::hash_entries_to(SymbolHash *symmap,
2081 SymbolHash *classmap) {
2082 jint size = 0;
2083
2084 for (u2 idx = 1; idx < length(); idx++) {
2085 u2 tag = tag_at(idx).value();
2086 size += cpool_entry_size(idx);
2087
2088 switch(tag) {
2089 case JVM_CONSTANT_Utf8: {
2090 Symbol* sym = symbol_at(idx);
2091 symmap->add_if_absent(sym, idx);
2092 break;
2093 }
2094 case JVM_CONSTANT_Class:
2095 case JVM_CONSTANT_UnresolvedClass:
2096 case JVM_CONSTANT_UnresolvedClassInError: {
2097 Symbol* sym = klass_name_at(idx);
2098 classmap->add_if_absent(sym, idx);
2099 break;
2100 }
2101 case JVM_CONSTANT_Long:
2102 case JVM_CONSTANT_Double: {
2103 idx++; // Both Long and Double take two cpool slots
2104 break;
2105 }
2106 }
2107 }
2108 return size;
2109 } /* end hash_utf8_entries_to */
2110
2111
2112 // Copy cpool bytes.
2113 // Returns:
2114 // 0, in case of OutOfMemoryError
2115 // -1, in case of internal error
2116 // > 0, count of the raw cpool bytes that have been copied
2117 int ConstantPool::copy_cpool_bytes(int cpool_size,
2118 SymbolHash* tbl,
2119 unsigned char *bytes) {
2120 u2 idx1, idx2;
2121 jint size = 0;
2122 jint cnt = length();
2123 unsigned char *start_bytes = bytes;
2124
2125 for (jint idx = 1; idx < cnt; idx++) {
2126 u1 tag = tag_at(idx).value();
2127 jint ent_size = cpool_entry_size(idx);
2128
2129 assert(size + ent_size <= cpool_size, "Size mismatch");
2130
2131 *bytes = tag;
2132 switch(tag) {
2133 case JVM_CONSTANT_Invalid: {
2134 break;
2135 }
2136 case JVM_CONSTANT_Unicode: {
2137 assert(false, "Wrong constant pool tag: JVM_CONSTANT_Unicode");
2138 break;
2139 }
2140 case JVM_CONSTANT_Utf8: {
2141 Symbol* sym = symbol_at(idx);
2142 char* str = sym->as_utf8();
2143 // Warning! It's crashing on x86 with len = sym->utf8_length()
2144 int len = (int) strlen(str);
2145 Bytes::put_Java_u2((address) (bytes+1), (u2) len);
2146 for (int i = 0; i < len; i++) {
2147 bytes[3+i] = (u1) str[i];
2148 }
2149 break;
2150 }
2151 case JVM_CONSTANT_Integer: {
2152 jint val = int_at(idx);
2153 Bytes::put_Java_u4((address) (bytes+1), *(u4*)&val);
2154 break;
2155 }
2156 case JVM_CONSTANT_Float: {
2157 jfloat val = float_at(idx);
2158 Bytes::put_Java_u4((address) (bytes+1), *(u4*)&val);
2159 break;
2160 }
2161 case JVM_CONSTANT_Long: {
2162 jlong val = long_at(idx);
2163 Bytes::put_Java_u8((address) (bytes+1), *(u8*)&val);
2164 idx++; // Long takes two cpool slots
2165 break;
2166 }
2167 case JVM_CONSTANT_Double: {
2168 jdouble val = double_at(idx);
2169 Bytes::put_Java_u8((address) (bytes+1), *(u8*)&val);
2170 idx++; // Double takes two cpool slots
2171 break;
2172 }
2173 case JVM_CONSTANT_Class:
2174 case JVM_CONSTANT_UnresolvedClass:
2175 case JVM_CONSTANT_UnresolvedClassInError: {
2176 *bytes = JVM_CONSTANT_Class;
2177 Symbol* sym = klass_name_at(idx);
2178 idx1 = tbl->symbol_to_value(sym);
2179 assert(idx1 != 0, "Have not found a hashtable entry");
2180 Bytes::put_Java_u2((address) (bytes+1), idx1);
2181 break;
2182 }
2183 case JVM_CONSTANT_String: {
2184 *bytes = JVM_CONSTANT_String;
2185 Symbol* sym = unresolved_string_at(idx);
2186 idx1 = tbl->symbol_to_value(sym);
2187 assert(idx1 != 0, "Have not found a hashtable entry");
2188 Bytes::put_Java_u2((address) (bytes+1), idx1);
2189 break;
2190 }
2191 case JVM_CONSTANT_Fieldref:
2192 case JVM_CONSTANT_Methodref:
2193 case JVM_CONSTANT_InterfaceMethodref: {
2194 idx1 = uncached_klass_ref_index_at(idx);
2195 idx2 = uncached_name_and_type_ref_index_at(idx);
2196 Bytes::put_Java_u2((address) (bytes+1), idx1);
2197 Bytes::put_Java_u2((address) (bytes+3), idx2);
2198 break;
2199 }
2200 case JVM_CONSTANT_NameAndType: {
2201 idx1 = name_ref_index_at(idx);
2202 idx2 = signature_ref_index_at(idx);
2203 Bytes::put_Java_u2((address) (bytes+1), idx1);
2204 Bytes::put_Java_u2((address) (bytes+3), idx2);
2205 break;
2206 }
2207 case JVM_CONSTANT_ClassIndex: {
2208 *bytes = JVM_CONSTANT_Class;
2209 idx1 = checked_cast<u2>(klass_index_at(idx));
2210 Bytes::put_Java_u2((address) (bytes+1), idx1);
2211 break;
2212 }
2213 case JVM_CONSTANT_StringIndex: {
2214 *bytes = JVM_CONSTANT_String;
2215 idx1 = checked_cast<u2>(string_index_at(idx));
2216 Bytes::put_Java_u2((address) (bytes+1), idx1);
2217 break;
2218 }
2219 case JVM_CONSTANT_MethodHandle:
2220 case JVM_CONSTANT_MethodHandleInError: {
2221 *bytes = JVM_CONSTANT_MethodHandle;
2222 int kind = method_handle_ref_kind_at(idx);
2223 idx1 = checked_cast<u2>(method_handle_index_at(idx));
2224 *(bytes+1) = (unsigned char) kind;
2225 Bytes::put_Java_u2((address) (bytes+2), idx1);
2226 break;
2227 }
2228 case JVM_CONSTANT_MethodType:
2229 case JVM_CONSTANT_MethodTypeInError: {
2230 *bytes = JVM_CONSTANT_MethodType;
2231 idx1 = checked_cast<u2>(method_type_index_at(idx));
2232 Bytes::put_Java_u2((address) (bytes+1), idx1);
2233 break;
2234 }
2235 case JVM_CONSTANT_Dynamic:
2236 case JVM_CONSTANT_DynamicInError: {
2237 *bytes = tag;
2238 idx1 = extract_low_short_from_int(*int_at_addr(idx));
2239 idx2 = extract_high_short_from_int(*int_at_addr(idx));
2240 assert(idx2 == bootstrap_name_and_type_ref_index_at(idx), "correct half of u4");
2241 Bytes::put_Java_u2((address) (bytes+1), idx1);
2242 Bytes::put_Java_u2((address) (bytes+3), idx2);
2243 break;
2244 }
2245 case JVM_CONSTANT_InvokeDynamic: {
2246 *bytes = tag;
2247 idx1 = extract_low_short_from_int(*int_at_addr(idx));
2248 idx2 = extract_high_short_from_int(*int_at_addr(idx));
2249 assert(idx2 == bootstrap_name_and_type_ref_index_at(idx), "correct half of u4");
2250 Bytes::put_Java_u2((address) (bytes+1), idx1);
2251 Bytes::put_Java_u2((address) (bytes+3), idx2);
2252 break;
2253 }
2254 }
2255 bytes += ent_size;
2256 size += ent_size;
2257 }
2258 assert(size == cpool_size, "Size mismatch");
2259
2260 return (int)(bytes - start_bytes);
2261 } /* end copy_cpool_bytes */
2262
2263 bool ConstantPool::is_maybe_on_stack() const {
2264 // This method uses the similar logic as nmethod::is_maybe_on_stack()
2265 if (!Continuations::enabled()) {
2266 return false;
2267 }
2268
2269 // If the condition below is true, it means that the nmethod was found to
2270 // be alive the previous completed marking cycle.
2271 return cache()->gc_epoch() >= CodeCache::previous_completed_gc_marking_cycle();
2272 }
2273
2274 // For redefinition, if any methods found in loom stack chunks, the gc_epoch is
2275 // recorded in their constant pool cache. The on_stack-ness of the constant pool controls whether
2276 // memory for the method is reclaimed.
2277 bool ConstantPool::on_stack() const {
2278 if ((_flags &_on_stack) != 0) {
2279 return true;
2280 }
2281
2282 if (_cache == nullptr) {
2283 return false;
2284 }
2285
2286 return is_maybe_on_stack();
2287 }
2288
2289 void ConstantPool::set_on_stack(const bool value) {
2290 if (value) {
2291 // Only record if it's not already set.
2292 if (!on_stack()) {
2293 assert(!in_aot_cache(), "should always be set for constant pools in AOT cache");
2294 _flags |= _on_stack;
2295 MetadataOnStackMark::record(this);
2296 }
2297 } else {
2298 // Clearing is done single-threadedly.
2299 if (!in_aot_cache()) {
2300 _flags &= (u2)(~_on_stack);
2301 }
2302 }
2303 }
2304
2305 // Printing
2306
2307 void ConstantPool::print_on(outputStream* st) const {
2308 assert(is_constantPool(), "must be constantPool");
2309 st->print_cr("%s", internal_name());
2310 if (flags() != 0) {
2311 st->print(" - flags: 0x%x", flags());
2312 if (has_preresolution()) st->print(" has_preresolution");
2313 if (on_stack()) st->print(" on_stack");
2314 st->cr();
2315 }
2316 if (pool_holder() != nullptr) {
2317 st->print_cr(" - holder: " PTR_FORMAT, p2i(pool_holder()));
2318 }
2319 st->print_cr(" - cache: " PTR_FORMAT, p2i(cache()));
2320 st->print_cr(" - resolved_references: " PTR_FORMAT, p2i(resolved_references_or_null()));
2321 st->print_cr(" - reference_map: " PTR_FORMAT, p2i(reference_map()));
2322 st->print_cr(" - resolved_klasses: " PTR_FORMAT, p2i(resolved_klasses()));
2323 st->print_cr(" - cp length: %d", length());
2324
2325 for (int index = 1; index < length(); index++) { // Index 0 is unused
2326 ((ConstantPool*)this)->print_entry_on(index, st);
2327 switch (tag_at(index).value()) {
2328 case JVM_CONSTANT_Long :
2329 case JVM_CONSTANT_Double :
2330 index++; // Skip entry following eigth-byte constant
2331 }
2332
2333 }
2334 st->cr();
2335 }
2336
2337 // Print one constant pool entry
2338 void ConstantPool::print_entry_on(const int cp_index, outputStream* st) {
2339 EXCEPTION_MARK;
2340 st->print(" - %3d : ", cp_index);
2341 tag_at(cp_index).print_on(st);
2342 st->print(" : ");
2343 switch (tag_at(cp_index).value()) {
2344 case JVM_CONSTANT_Class :
2345 { Klass* k = klass_at(cp_index, CATCH);
2346 guarantee(k != nullptr, "need klass");
2347 k->print_value_on(st);
2348 st->print(" {" PTR_FORMAT "}", p2i(k));
2349 }
2350 break;
2351 case JVM_CONSTANT_Fieldref :
2352 case JVM_CONSTANT_Methodref :
2353 case JVM_CONSTANT_InterfaceMethodref :
2354 st->print("klass_index=%d", uncached_klass_ref_index_at(cp_index));
2355 st->print(" name_and_type_index=%d", uncached_name_and_type_ref_index_at(cp_index));
2356 break;
2357 case JVM_CONSTANT_String :
2358 unresolved_string_at(cp_index)->print_value_on(st);
2359 break;
2360 case JVM_CONSTANT_Integer :
2361 st->print("%d", int_at(cp_index));
2362 break;
2363 case JVM_CONSTANT_Float :
2364 st->print("%f", float_at(cp_index));
2365 break;
2366 case JVM_CONSTANT_Long :
2367 st->print_jlong(long_at(cp_index));
2368 break;
2369 case JVM_CONSTANT_Double :
2370 st->print("%lf", double_at(cp_index));
2371 break;
2372 case JVM_CONSTANT_NameAndType :
2373 st->print("name_index=%d", name_ref_index_at(cp_index));
2374 st->print(" signature_index=%d", signature_ref_index_at(cp_index));
2375 break;
2376 case JVM_CONSTANT_Utf8 :
2377 symbol_at(cp_index)->print_value_on(st);
2378 break;
2379 case JVM_CONSTANT_ClassIndex: {
2380 int name_index = *int_at_addr(cp_index);
2381 st->print("klass_index=%d ", name_index);
2382 symbol_at(name_index)->print_value_on(st);
2383 }
2384 break;
2385 case JVM_CONSTANT_UnresolvedClass : // fall-through
2386 case JVM_CONSTANT_UnresolvedClassInError: {
2387 CPKlassSlot kslot = klass_slot_at(cp_index);
2388 int resolved_klass_index = kslot.resolved_klass_index();
2389 int name_index = kslot.name_index();
2390 assert(tag_at(name_index).is_symbol(), "sanity");
2391 symbol_at(name_index)->print_value_on(st);
2392 }
2393 break;
2394 case JVM_CONSTANT_MethodHandle :
2395 case JVM_CONSTANT_MethodHandleInError :
2396 st->print("ref_kind=%d", method_handle_ref_kind_at(cp_index));
2397 st->print(" ref_index=%d", method_handle_index_at(cp_index));
2398 break;
2399 case JVM_CONSTANT_MethodType :
2400 case JVM_CONSTANT_MethodTypeInError :
2401 st->print("signature_index=%d", method_type_index_at(cp_index));
2402 break;
2403 case JVM_CONSTANT_Dynamic :
2404 case JVM_CONSTANT_DynamicInError :
2405 {
2406 st->print("bootstrap_method_index=%d", bootstrap_method_ref_index_at(cp_index));
2407 st->print(" type_index=%d", bootstrap_name_and_type_ref_index_at(cp_index));
2408 int argc = bootstrap_argument_count_at(cp_index);
2409 if (argc > 0) {
2410 for (int arg_i = 0; arg_i < argc; arg_i++) {
2411 int arg = bootstrap_argument_index_at(cp_index, arg_i);
2412 st->print((arg_i == 0 ? " arguments={%d" : ", %d"), arg);
2413 }
2414 st->print("}");
2415 }
2416 }
2417 break;
2418 case JVM_CONSTANT_InvokeDynamic :
2419 {
2420 st->print("bootstrap_method_index=%d", bootstrap_method_ref_index_at(cp_index));
2421 st->print(" name_and_type_index=%d", bootstrap_name_and_type_ref_index_at(cp_index));
2422 int argc = bootstrap_argument_count_at(cp_index);
2423 if (argc > 0) {
2424 for (int arg_i = 0; arg_i < argc; arg_i++) {
2425 int arg = bootstrap_argument_index_at(cp_index, arg_i);
2426 st->print((arg_i == 0 ? " arguments={%d" : ", %d"), arg);
2427 }
2428 st->print("}");
2429 }
2430 }
2431 break;
2432 default:
2433 ShouldNotReachHere();
2434 break;
2435 }
2436 st->cr();
2437 }
2438
2439 void ConstantPool::print_value_on(outputStream* st) const {
2440 assert(is_constantPool(), "must be constantPool");
2441 st->print("constant pool [%d]", length());
2442 if (has_preresolution()) st->print("/preresolution");
2443 if (operands() != nullptr) st->print("/operands[%d]", operands()->length());
2444 print_address_on(st);
2445 if (pool_holder() != nullptr) {
2446 st->print(" for ");
2447 pool_holder()->print_value_on(st);
2448 bool extra = (pool_holder()->constants() != this);
2449 if (extra) st->print(" (extra)");
2450 }
2451 if (cache() != nullptr) {
2452 st->print(" cache=" PTR_FORMAT, p2i(cache()));
2453 }
2454 }
2455
2456 // Verification
2457
2458 void ConstantPool::verify_on(outputStream* st) {
2459 guarantee(is_constantPool(), "object must be constant pool");
2460 for (int i = 0; i< length(); i++) {
2461 constantTag tag = tag_at(i);
2462 if (tag.is_klass() || tag.is_unresolved_klass()) {
2463 guarantee(klass_name_at(i)->refcount() != 0, "should have nonzero reference count");
2464 } else if (tag.is_symbol()) {
2465 Symbol* entry = symbol_at(i);
2466 guarantee(entry->refcount() != 0, "should have nonzero reference count");
2467 } else if (tag.is_string()) {
2468 Symbol* entry = unresolved_string_at(i);
2469 guarantee(entry->refcount() != 0, "should have nonzero reference count");
2470 }
2471 }
2472 if (pool_holder() != nullptr) {
2473 // Note: pool_holder() can be null in temporary constant pools
2474 // used during constant pool merging
2475 guarantee(pool_holder()->is_klass(), "should be klass");
2476 }
2477 }