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