1 /*
2 * Copyright (c) 1997, 2024, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "cds/archiveHeapWriter.hpp"
27 #include "cds/archiveHeapLoader.hpp"
28 #include "cds/archiveBuilder.hpp"
29 #include "cds/cdsConfig.hpp"
30 #include "cds/classPrelinker.hpp"
31 #include "cds/heapShared.hpp"
32 #include "classfile/classLoader.hpp"
33 #include "classfile/classLoaderData.hpp"
34 #include "classfile/javaClasses.inline.hpp"
35 #include "classfile/metadataOnStackMark.hpp"
36 #include "classfile/stringTable.hpp"
37 #include "classfile/systemDictionary.hpp"
38 #include "classfile/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/flatArrayKlass.hpp"
56 #include "oops/instanceKlass.hpp"
57 #include "oops/klass.inline.hpp"
58 #include "oops/objArrayKlass.hpp"
59 #include "oops/objArrayOop.inline.hpp"
60 #include "oops/oop.inline.hpp"
61 #include "oops/typeArrayOop.inline.hpp"
62 #include "prims/jvmtiExport.hpp"
63 #include "runtime/atomic.hpp"
64 #include "runtime/handles.inline.hpp"
65 #include "runtime/init.hpp"
66 #include "runtime/javaCalls.hpp"
67 #include "runtime/javaThread.inline.hpp"
68 #include "runtime/perfData.hpp"
69 #include "runtime/signature.hpp"
70 #include "runtime/vframe.inline.hpp"
71 #include "utilities/checkedCast.hpp"
72 #include "utilities/copy.hpp"
73
74 ConstantPool* ConstantPool::allocate(ClassLoaderData* loader_data, int length, TRAPS) {
75 Array<u1>* tags = MetadataFactory::new_array<u1>(loader_data, length, 0, CHECK_NULL);
76 int size = ConstantPool::size(length);
77 return new (loader_data, size, MetaspaceObj::ConstantPoolType, THREAD) ConstantPool(tags);
78 }
79
80 void ConstantPool::copy_fields(const ConstantPool* orig) {
81 // Preserve dynamic constant information from the original pool
82 if (orig->has_dynamic_constant()) {
83 set_has_dynamic_constant();
84 }
85
86 set_major_version(orig->major_version());
87 set_minor_version(orig->minor_version());
88
89 set_source_file_name_index(orig->source_file_name_index());
90 set_generic_signature_index(orig->generic_signature_index());
91 }
92
93 #ifdef ASSERT
94
95 // MetaspaceObj allocation invariant is calloc equivalent memory
96 // simple verification of this here (JVM_CONSTANT_Invalid == 0 )
97 static bool tag_array_is_zero_initialized(Array<u1>* tags) {
98 assert(tags != nullptr, "invariant");
99 const int length = tags->length();
100 for (int index = 0; index < length; ++index) {
101 if (JVM_CONSTANT_Invalid != tags->at(index)) {
102 return false;
103 }
104 }
105 return true;
106 }
107
108 #endif
109
110 ConstantPool::ConstantPool() {
111 assert(CDSConfig::is_dumping_static_archive() || CDSConfig::is_using_archive(), "only for CDS");
112 }
113
114 ConstantPool::ConstantPool(Array<u1>* tags) :
115 _tags(tags),
116 _length(tags->length()) {
117
118 assert(_tags != nullptr, "invariant");
119 assert(tags->length() == _length, "invariant");
120 assert(tag_array_is_zero_initialized(tags), "invariant");
121 assert(0 == flags(), "invariant");
122 assert(0 == version(), "invariant");
123 assert(nullptr == _pool_holder, "invariant");
124 }
125
126 void ConstantPool::deallocate_contents(ClassLoaderData* loader_data) {
127 if (cache() != nullptr) {
128 MetadataFactory::free_metadata(loader_data, cache());
129 set_cache(nullptr);
130 }
131
132 MetadataFactory::free_array<Klass*>(loader_data, resolved_klasses());
133 set_resolved_klasses(nullptr);
134
135 MetadataFactory::free_array<jushort>(loader_data, operands());
136 set_operands(nullptr);
137
138 release_C_heap_structures();
139
140 // free tag array
141 MetadataFactory::free_array<u1>(loader_data, tags());
142 set_tags(nullptr);
143 }
144
145 void ConstantPool::release_C_heap_structures() {
146 // walk constant pool and decrement symbol reference counts
147 unreference_symbols();
148 }
149
150 void ConstantPool::metaspace_pointers_do(MetaspaceClosure* it) {
151 log_trace(cds)("Iter(ConstantPool): %p", this);
152
153 it->push(&_tags, MetaspaceClosure::_writable);
154 it->push(&_cache);
155 it->push(&_pool_holder);
156 it->push(&_operands);
157 it->push(&_resolved_klasses, MetaspaceClosure::_writable);
158
159 for (int i = 0; i < length(); i++) {
160 // The only MSO's embedded in the CP entries are Symbols:
161 // JVM_CONSTANT_String
162 // JVM_CONSTANT_Utf8
163 constantTag ctag = tag_at(i);
164 if (ctag.is_string() || ctag.is_utf8()) {
165 it->push(symbol_at_addr(i));
166 }
167 }
168 }
169
170 objArrayOop ConstantPool::resolved_references() const {
171 return _cache->resolved_references();
172 }
173
174 // Called from outside constant pool resolution where a resolved_reference array
175 // may not be present.
176 objArrayOop ConstantPool::resolved_references_or_null() const {
177 if (_cache == nullptr) {
178 return nullptr;
179 } else {
180 return _cache->resolved_references();
181 }
182 }
183
184 oop ConstantPool::resolved_reference_at(int index) const {
185 oop result = resolved_references()->obj_at(index);
186 assert(oopDesc::is_oop_or_null(result), "Must be oop");
187 return result;
188 }
189
190 // Use a CAS for multithreaded access
191 oop ConstantPool::set_resolved_reference_at(int index, oop new_result) {
192 assert(oopDesc::is_oop_or_null(new_result), "Must be oop");
193 return resolved_references()->replace_if_null(index, new_result);
194 }
195
196 // Create resolved_references array and mapping array for original cp indexes
197 // The ldc bytecode was rewritten to have the resolved reference array index so need a way
198 // to map it back for resolving and some unlikely miscellaneous uses.
199 // The objects created by invokedynamic are appended to this list.
200 void ConstantPool::initialize_resolved_references(ClassLoaderData* loader_data,
201 const intStack& reference_map,
202 int constant_pool_map_length,
203 TRAPS) {
204 // Initialized the resolved object cache.
205 int map_length = reference_map.length();
206 if (map_length > 0) {
207 // Only need mapping back to constant pool entries. The map isn't used for
208 // invokedynamic resolved_reference entries. For invokedynamic entries,
209 // the constant pool cache index has the mapping back to both the constant
210 // pool and to the resolved reference index.
211 if (constant_pool_map_length > 0) {
212 Array<u2>* om = MetadataFactory::new_array<u2>(loader_data, constant_pool_map_length, CHECK);
213
214 for (int i = 0; i < constant_pool_map_length; i++) {
215 int x = reference_map.at(i);
216 assert(x == (int)(jushort) x, "klass index is too big");
217 om->at_put(i, (jushort)x);
218 }
219 set_reference_map(om);
220 }
221
222 // Create Java array for holding resolved strings, methodHandles,
223 // methodTypes, invokedynamic and invokehandle appendix objects, etc.
224 objArrayOop stom = oopFactory::new_objArray(vmClasses::Object_klass(), map_length, CHECK);
225 HandleMark hm(THREAD);
226 Handle refs_handle (THREAD, stom); // must handleize.
227 set_resolved_references(loader_data->add_handle(refs_handle));
228
229 // Create a "scratch" copy of the resolved references array to archive
230 if (CDSConfig::is_dumping_heap()) {
231 objArrayOop scratch_references = oopFactory::new_objArray(vmClasses::Object_klass(), map_length, CHECK);
232 HeapShared::add_scratch_resolved_references(this, scratch_references);
233 }
234 }
235 }
236
237 void ConstantPool::allocate_resolved_klasses(ClassLoaderData* loader_data, int num_klasses, TRAPS) {
238 // A ConstantPool can't possibly have 0xffff valid class entries,
239 // because entry #0 must be CONSTANT_Invalid, and each class entry must refer to a UTF8
240 // entry for the class's name. So at most we will have 0xfffe class entries.
241 // This allows us to use 0xffff (ConstantPool::_temp_resolved_klass_index) to indicate
242 // UnresolvedKlass entries that are temporarily created during class redefinition.
243 assert(num_klasses < CPKlassSlot::_temp_resolved_klass_index, "sanity");
244 assert(resolved_klasses() == nullptr, "sanity");
245 Array<Klass*>* rk = MetadataFactory::new_array<Klass*>(loader_data, num_klasses, CHECK);
246 set_resolved_klasses(rk);
247 }
248
249 void ConstantPool::initialize_unresolved_klasses(ClassLoaderData* loader_data, TRAPS) {
250 int len = length();
251 int num_klasses = 0;
252 for (int i = 1; i <len; i++) {
253 switch (tag_at(i).value()) {
254 case JVM_CONSTANT_ClassIndex:
255 {
256 const int class_index = klass_index_at(i);
257 unresolved_klass_at_put(i, class_index, num_klasses++);
258 }
259 break;
260 #ifndef PRODUCT
261 case JVM_CONSTANT_Class:
262 case JVM_CONSTANT_UnresolvedClass:
263 case JVM_CONSTANT_UnresolvedClassInError:
264 // All of these should have been reverted back to Unresolved before calling
265 // this function.
266 ShouldNotReachHere();
267 #endif
268 }
269 }
270 allocate_resolved_klasses(loader_data, num_klasses, THREAD);
271 }
272
273 // Hidden class support:
274 void ConstantPool::klass_at_put(int class_index, Klass* k) {
275 assert(k != nullptr, "must be valid klass");
276 CPKlassSlot kslot = klass_slot_at(class_index);
277 int resolved_klass_index = kslot.resolved_klass_index();
278 Klass** adr = resolved_klasses()->adr_at(resolved_klass_index);
279 Atomic::release_store(adr, k);
280
281 // The interpreter assumes when the tag is stored, the klass is resolved
282 // and the Klass* non-null, so we need hardware store ordering here.
283 release_tag_at_put(class_index, JVM_CONSTANT_Class);
284 }
285
286 #if INCLUDE_CDS_JAVA_HEAP
287 // Returns the _resolved_reference array after removing unarchivable items from it.
288 // Returns null if this class is not supported, or _resolved_reference doesn't exist.
289 objArrayOop ConstantPool::prepare_resolved_references_for_archiving() {
290 if (_cache == nullptr) {
291 return nullptr; // nothing to do
292 }
293
294 InstanceKlass *ik = pool_holder();
295 if (!(ik->is_shared_boot_class() || ik->is_shared_platform_class() ||
296 ik->is_shared_app_class())) {
297 // Archiving resolved references for classes from non-builtin loaders
298 // is not yet supported.
299 return nullptr;
300 }
301
302 objArrayOop rr = resolved_references();
303 if (rr != nullptr) {
304 int rr_len = rr->length();
305 ConstantPool* src_cp = ArchiveBuilder::current()->get_source_addr(this);
306 objArrayOop scratch_rr = HeapShared::scratch_resolved_references(src_cp);
307 Array<u2>* ref_map = reference_map();
308 int ref_map_len = ref_map == nullptr ? 0 : ref_map->length();
309 for (int i = 0; i < rr_len; i++) {
310 oop obj = rr->obj_at(i);
311 scratch_rr->obj_at_put(i, nullptr);
312 if (obj != nullptr) {
313 if (i < ref_map_len) {
314 int index = object_to_cp_index(i);
315 if (tag_at(index).is_string()) {
316 assert(java_lang_String::is_instance(obj), "must be");
317 if (!ArchiveHeapWriter::is_string_too_large_to_archive(obj)) {
318 scratch_rr->obj_at_put(i, obj);
319 }
320 }
321 }
322 }
323 }
324 return scratch_rr;
325 }
326 return rr;
327 }
328
329 void ConstantPool::add_dumped_interned_strings() {
330 objArrayOop rr = resolved_references();
331 if (rr != nullptr) {
332 int rr_len = rr->length();
333 for (int i = 0; i < rr_len; i++) {
334 oop p = rr->obj_at(i);
335 if (java_lang_String::is_instance(p) &&
336 !ArchiveHeapWriter::is_string_too_large_to_archive(p)) {
337 HeapShared::add_to_dumped_interned_strings(p);
338 }
339 }
340 }
341 }
342 #endif
343
344 #if INCLUDE_CDS
345 // CDS support. Create a new resolved_references array.
346 void ConstantPool::restore_unshareable_info(TRAPS) {
347 if (!_pool_holder->is_linked() && !_pool_holder->is_rewritten()) {
348 return;
349 }
350 assert(is_constantPool(), "ensure C++ vtable is restored");
351 assert(on_stack(), "should always be set for shared constant pools");
352 assert(is_shared(), "should always be set for shared constant pools");
353 assert(_cache != nullptr, "constant pool _cache should not be null");
354
355 // Only create the new resolved references array if it hasn't been attempted before
356 if (resolved_references() != nullptr) return;
357
358 if (vmClasses::Object_klass_loaded()) {
359 ClassLoaderData* loader_data = pool_holder()->class_loader_data();
360 #if INCLUDE_CDS_JAVA_HEAP
361 if (ArchiveHeapLoader::is_in_use() &&
362 _cache->archived_references() != nullptr) {
363 oop archived = _cache->archived_references();
364 // Create handle for the archived resolved reference array object
365 HandleMark hm(THREAD);
366 Handle refs_handle(THREAD, archived);
367 set_resolved_references(loader_data->add_handle(refs_handle));
368 _cache->clear_archived_references();
369 } else
370 #endif
371 {
372 // No mapped archived resolved reference array
373 // Recreate the object array and add to ClassLoaderData.
374 int map_length = resolved_reference_length();
375 if (map_length > 0) {
376 objArrayOop stom = oopFactory::new_objArray(vmClasses::Object_klass(), map_length, CHECK);
377 HandleMark hm(THREAD);
378 Handle refs_handle(THREAD, stom); // must handleize.
379 set_resolved_references(loader_data->add_handle(refs_handle));
380 }
381 }
382 }
383 }
384
385 void ConstantPool::remove_unshareable_info() {
386 // Shared ConstantPools are in the RO region, so the _flags cannot be modified.
387 // The _on_stack flag is used to prevent ConstantPools from deallocation during
388 // class redefinition. Since shared ConstantPools cannot be deallocated anyway,
389 // we always set _on_stack to true to avoid having to change _flags during runtime.
390 _flags |= (_on_stack | _is_shared);
391
392 // resolved_references(): remember its length. If it cannot be restored
393 // from the archived heap objects at run time, we need to dynamically allocate it.
394 if (cache() != nullptr) {
395 set_resolved_reference_length(
396 resolved_references() != nullptr ? resolved_references()->length() : 0);
397 set_resolved_references(OopHandle());
398 }
399 remove_unshareable_entries();
400 }
401
402 static const char* get_type(Klass* k) {
403 const char* type;
404 Klass* src_k;
405 if (ArchiveBuilder::is_active() && ArchiveBuilder::current()->is_in_buffer_space(k)) {
406 src_k = ArchiveBuilder::current()->get_source_addr(k);
407 } else {
408 src_k = k;
409 }
410
411 if (src_k->is_objArray_klass()) {
412 src_k = ObjArrayKlass::cast(src_k)->bottom_klass();
413 assert(!src_k->is_objArray_klass(), "sanity");
414 }
415
416 if (src_k->is_typeArray_klass()) {
417 type = "prim";
418 } else {
419 InstanceKlass* src_ik = InstanceKlass::cast(src_k);
420 oop loader = src_ik->class_loader();
421 if (loader == nullptr) {
422 type = "boot";
423 } else if (loader == SystemDictionary::java_platform_loader()) {
424 type = "plat";
425 } else if (loader == SystemDictionary::java_system_loader()) {
426 type = "app";
427 } else {
428 type = "unreg";
429 }
430 }
431
432 return type;
433 }
434
435 void ConstantPool::remove_unshareable_entries() {
436 ResourceMark rm;
437 log_info(cds, resolve)("Archiving CP entries for %s", pool_holder()->name()->as_C_string());
438 for (int cp_index = 1; cp_index < length(); cp_index++) { // cp_index 0 is unused
439 int cp_tag = tag_at(cp_index).value();
440 switch (cp_tag) {
441 case JVM_CONSTANT_UnresolvedClass:
442 ArchiveBuilder::alloc_stats()->record_klass_cp_entry(false, false);
443 break;
444 case JVM_CONSTANT_UnresolvedClassInError:
445 tag_at_put(cp_index, JVM_CONSTANT_UnresolvedClass);
446 ArchiveBuilder::alloc_stats()->record_klass_cp_entry(false, true);
447 break;
448 case JVM_CONSTANT_MethodHandleInError:
449 tag_at_put(cp_index, JVM_CONSTANT_MethodHandle);
450 break;
451 case JVM_CONSTANT_MethodTypeInError:
452 tag_at_put(cp_index, JVM_CONSTANT_MethodType);
453 break;
454 case JVM_CONSTANT_DynamicInError:
455 tag_at_put(cp_index, JVM_CONSTANT_Dynamic);
456 break;
457 case JVM_CONSTANT_Class:
458 remove_resolved_klass_if_non_deterministic(cp_index);
459 break;
460 default:
461 break;
462 }
463 }
464
465 if (cache() != nullptr) {
466 // cache() is null if this class is not yet linked.
467 cache()->remove_unshareable_info();
468 }
469 }
470
471 void ConstantPool::remove_resolved_klass_if_non_deterministic(int cp_index) {
472 assert(ArchiveBuilder::current()->is_in_buffer_space(this), "must be");
473 assert(tag_at(cp_index).is_klass(), "must be resolved");
474
475 Klass* k = resolved_klass_at(cp_index);
476 bool can_archive;
477
478 if (k == nullptr) {
479 // We'd come here if the referenced class has been excluded via
480 // SystemDictionaryShared::is_excluded_class(). As a result, ArchiveBuilder
481 // has cleared the resolved_klasses()->at(...) pointer to NULL. Thus, we
482 // need to revert the tag to JVM_CONSTANT_UnresolvedClass.
483 can_archive = false;
484 } else {
485 ConstantPool* src_cp = ArchiveBuilder::current()->get_source_addr(this);
486 can_archive = ClassPrelinker::is_resolution_deterministic(src_cp, cp_index);
487 }
488
489 if (!can_archive) {
490 int resolved_klass_index = klass_slot_at(cp_index).resolved_klass_index();
491 resolved_klasses()->at_put(resolved_klass_index, nullptr);
492 tag_at_put(cp_index, JVM_CONSTANT_UnresolvedClass);
493 }
494
495 LogStreamHandle(Trace, cds, resolve) log;
496 if (log.is_enabled()) {
497 ResourceMark rm;
498 log.print("%s klass CP entry [%3d]: %s %s",
499 (can_archive ? "archived" : "reverted"),
500 cp_index, pool_holder()->name()->as_C_string(), get_type(pool_holder()));
501 if (can_archive) {
502 log.print(" => %s %s%s", k->name()->as_C_string(), get_type(k),
503 (!k->is_instance_klass() || pool_holder()->is_subtype_of(k)) ? "" : " (not supertype)");
504 } else {
505 Symbol* name = klass_name_at(cp_index);
506 log.print(" %s", name->as_C_string());
507 }
508 }
509
510 ArchiveBuilder::alloc_stats()->record_klass_cp_entry(can_archive, /*reverted=*/!can_archive);
511 }
512 #endif // INCLUDE_CDS
513
514 int ConstantPool::cp_to_object_index(int cp_index) {
515 // this is harder don't do this so much.
516 int i = reference_map()->find(checked_cast<u2>(cp_index));
517 // We might not find the index for jsr292 call.
518 return (i < 0) ? _no_index_sentinel : i;
519 }
520
521 void ConstantPool::string_at_put(int obj_index, oop str) {
522 oop result = set_resolved_reference_at(obj_index, str);
523 assert(result == nullptr || result == str, "Only set once or to the same string.");
524 }
525
526 void ConstantPool::trace_class_resolution(const constantPoolHandle& this_cp, Klass* k) {
527 ResourceMark rm;
528 int line_number = -1;
529 const char * source_file = nullptr;
530 if (JavaThread::current()->has_last_Java_frame()) {
531 // try to identify the method which called this function.
532 vframeStream vfst(JavaThread::current());
533 if (!vfst.at_end()) {
534 line_number = vfst.method()->line_number_from_bci(vfst.bci());
535 Symbol* s = vfst.method()->method_holder()->source_file_name();
536 if (s != nullptr) {
537 source_file = s->as_C_string();
538 }
539 }
540 }
541 if (k != this_cp->pool_holder()) {
542 // only print something if the classes are different
543 if (source_file != nullptr) {
544 log_debug(class, resolve)("%s %s %s:%d",
545 this_cp->pool_holder()->external_name(),
546 k->external_name(), source_file, line_number);
547 } else {
548 log_debug(class, resolve)("%s %s",
549 this_cp->pool_holder()->external_name(),
550 k->external_name());
551 }
552 }
553 }
554
555 void check_is_inline_type(Klass* k, TRAPS) {
556 if (!k->is_inline_klass()) {
557 THROW(vmSymbols::java_lang_IncompatibleClassChangeError());
558 }
559 }
560
561 Klass* ConstantPool::klass_at_impl(const constantPoolHandle& this_cp, int cp_index,
562 TRAPS) {
563 JavaThread* javaThread = THREAD;
564
565 // A resolved constantPool entry will contain a Klass*, otherwise a Symbol*.
566 // It is not safe to rely on the tag bit's here, since we don't have a lock, and
567 // the entry and tag is not updated atomically.
568 CPKlassSlot kslot = this_cp->klass_slot_at(cp_index);
569 int resolved_klass_index = kslot.resolved_klass_index();
570 int name_index = kslot.name_index();
571 assert(this_cp->tag_at(name_index).is_symbol(), "sanity");
572
573 // The tag must be JVM_CONSTANT_Class in order to read the correct value from
574 // the unresolved_klasses() array.
575 if (this_cp->tag_at(cp_index).is_klass()) {
576 Klass* klass = this_cp->resolved_klasses()->at(resolved_klass_index);
577 if (klass != nullptr) {
578 return klass;
579 }
580 }
581
582 // This tag doesn't change back to unresolved class unless at a safepoint.
583 if (this_cp->tag_at(cp_index).is_unresolved_klass_in_error()) {
584 // The original attempt to resolve this constant pool entry failed so find the
585 // class of the original error and throw another error of the same class
586 // (JVMS 5.4.3).
587 // If there is a detail message, pass that detail message to the error.
588 // The JVMS does not strictly require us to duplicate the same detail message,
589 // or any internal exception fields such as cause or stacktrace. But since the
590 // detail message is often a class name or other literal string, we will repeat it
591 // if we can find it in the symbol table.
592 throw_resolution_error(this_cp, cp_index, CHECK_NULL);
593 ShouldNotReachHere();
594 }
595
596 HandleMark hm(THREAD);
597 Handle mirror_handle;
598 Symbol* name = this_cp->symbol_at(name_index);
599 bool inline_type_signature = false;
600 Handle loader (THREAD, this_cp->pool_holder()->class_loader());
601 Handle protection_domain (THREAD, this_cp->pool_holder()->protection_domain());
602
603 Klass* k;
604 {
605 // Turn off the single stepping while doing class resolution
606 JvmtiHideSingleStepping jhss(javaThread);
607 k = SystemDictionary::resolve_or_fail(name, loader, protection_domain, true, THREAD);
608 } // JvmtiHideSingleStepping jhss(javaThread);
609 if (inline_type_signature) {
610 name->decrement_refcount();
611 }
612
613 if (!HAS_PENDING_EXCEPTION) {
614 // preserve the resolved klass from unloading
615 mirror_handle = Handle(THREAD, k->java_mirror());
616 // Do access check for klasses
617 verify_constant_pool_resolve(this_cp, k, THREAD);
618 }
619
620 if (!HAS_PENDING_EXCEPTION && inline_type_signature) {
621 check_is_inline_type(k, THREAD);
622 }
623
624 if (!HAS_PENDING_EXCEPTION) {
625 Klass* bottom_klass = nullptr;
626 if (k->is_objArray_klass()) {
627 bottom_klass = ObjArrayKlass::cast(k)->bottom_klass();
628 assert(bottom_klass != nullptr, "Should be set");
629 assert(bottom_klass->is_instance_klass() || bottom_klass->is_typeArray_klass(), "Sanity check");
630 } else if (k->is_flatArray_klass()) {
631 bottom_klass = FlatArrayKlass::cast(k)->element_klass();
632 assert(bottom_klass != nullptr, "Should be set");
633 }
634 }
635
636 // Failed to resolve class. We must record the errors so that subsequent attempts
637 // to resolve this constant pool entry fail with the same error (JVMS 5.4.3).
638 if (HAS_PENDING_EXCEPTION) {
639 save_and_throw_exception(this_cp, cp_index, constantTag(JVM_CONSTANT_UnresolvedClass), CHECK_NULL);
640 // If CHECK_NULL above doesn't return the exception, that means that
641 // some other thread has beaten us and has resolved the class.
642 // To preserve old behavior, we return the resolved class.
643 Klass* klass = this_cp->resolved_klasses()->at(resolved_klass_index);
644 assert(klass != nullptr, "must be resolved if exception was cleared");
645 return klass;
646 }
647
648 // logging for class+resolve.
649 if (log_is_enabled(Debug, class, resolve)){
650 trace_class_resolution(this_cp, k);
651 }
652
653 Klass** adr = this_cp->resolved_klasses()->adr_at(resolved_klass_index);
654 Atomic::release_store(adr, k);
655 // The interpreter assumes when the tag is stored, the klass is resolved
656 // and the Klass* stored in _resolved_klasses is non-null, so we need
657 // hardware store ordering here.
658 // We also need to CAS to not overwrite an error from a racing thread.
659
660 jbyte old_tag = Atomic::cmpxchg((jbyte*)this_cp->tag_addr_at(cp_index),
661 (jbyte)JVM_CONSTANT_UnresolvedClass,
662 (jbyte)JVM_CONSTANT_Class);
663
664 // We need to recheck exceptions from racing thread and return the same.
665 if (old_tag == JVM_CONSTANT_UnresolvedClassInError) {
666 // Remove klass.
667 this_cp->resolved_klasses()->at_put(resolved_klass_index, nullptr);
668 throw_resolution_error(this_cp, cp_index, CHECK_NULL);
669 }
670
671 return k;
672 }
673
674
675 // Does not update ConstantPool* - to avoid any exception throwing. Used
676 // by compiler and exception handling. Also used to avoid classloads for
677 // instanceof operations. Returns null if the class has not been loaded or
678 // if the verification of constant pool failed
679 Klass* ConstantPool::klass_at_if_loaded(const constantPoolHandle& this_cp, int which) {
680 CPKlassSlot kslot = this_cp->klass_slot_at(which);
681 int resolved_klass_index = kslot.resolved_klass_index();
682 int name_index = kslot.name_index();
683 assert(this_cp->tag_at(name_index).is_symbol(), "sanity");
684
685 if (this_cp->tag_at(which).is_klass()) {
686 Klass* k = this_cp->resolved_klasses()->at(resolved_klass_index);
687 assert(k != nullptr, "should be resolved");
688 return k;
689 } else if (this_cp->tag_at(which).is_unresolved_klass_in_error()) {
690 return nullptr;
691 } else {
692 Thread* current = Thread::current();
693 HandleMark hm(current);
694 Symbol* name = this_cp->symbol_at(name_index);
695 oop loader = this_cp->pool_holder()->class_loader();
696 oop protection_domain = this_cp->pool_holder()->protection_domain();
697 Handle h_prot (current, protection_domain);
698 Handle h_loader (current, loader);
699 Klass* k = SystemDictionary::find_instance_klass(current, name, h_loader, h_prot);
700
701 // Avoid constant pool verification at a safepoint, as it takes the Module_lock.
702 if (k != nullptr && current->is_Java_thread()) {
703 // Make sure that resolving is legal
704 JavaThread* THREAD = JavaThread::cast(current); // For exception macros.
705 ExceptionMark em(THREAD);
706 // return null if verification fails
707 verify_constant_pool_resolve(this_cp, k, THREAD);
708 if (HAS_PENDING_EXCEPTION) {
709 CLEAR_PENDING_EXCEPTION;
710 return nullptr;
711 }
712 return k;
713 } else {
714 return k;
715 }
716 }
717 }
718
719 Method* ConstantPool::method_at_if_loaded(const constantPoolHandle& cpool,
720 int which) {
721 if (cpool->cache() == nullptr) return nullptr; // nothing to load yet
722 if (!(which >= 0 && which < cpool->resolved_method_entries_length())) {
723 // FIXME: should be an assert
724 log_debug(class, resolve)("bad operand %d in:", which); cpool->print();
725 return nullptr;
726 }
727 return cpool->cache()->method_if_resolved(which);
728 }
729
730
731 bool ConstantPool::has_appendix_at_if_loaded(const constantPoolHandle& cpool, int which, Bytecodes::Code code) {
732 if (cpool->cache() == nullptr) return false; // nothing to load yet
733 if (code == Bytecodes::_invokedynamic) {
734 return cpool->resolved_indy_entry_at(which)->has_appendix();
735 } else {
736 return cpool->resolved_method_entry_at(which)->has_appendix();
737 }
738 }
739
740 oop ConstantPool::appendix_at_if_loaded(const constantPoolHandle& cpool, int which, Bytecodes::Code code) {
741 if (cpool->cache() == nullptr) return nullptr; // nothing to load yet
742 if (code == Bytecodes::_invokedynamic) {
743 return cpool->resolved_reference_from_indy(which);
744 } else {
745 return cpool->cache()->appendix_if_resolved(which);
746 }
747 }
748
749
750 bool ConstantPool::has_local_signature_at_if_loaded(const constantPoolHandle& cpool, int which, Bytecodes::Code code) {
751 if (cpool->cache() == nullptr) return false; // nothing to load yet
752 if (code == Bytecodes::_invokedynamic) {
753 return cpool->resolved_indy_entry_at(which)->has_local_signature();
754 } else {
755 return cpool->resolved_method_entry_at(which)->has_local_signature();
756 }
757 }
758
759 // Translate index, which could be CPCache index or Indy index, to a constant pool index
760 int ConstantPool::to_cp_index(int index, Bytecodes::Code code) {
761 assert(cache() != nullptr, "'index' is a rewritten index so this class must have been rewritten");
762 switch(code) {
763 case Bytecodes::_invokedynamic:
764 return invokedynamic_bootstrap_ref_index_at(index);
765 case Bytecodes::_getfield:
766 case Bytecodes::_getstatic:
767 case Bytecodes::_putfield:
768 case Bytecodes::_putstatic:
769 return resolved_field_entry_at(index)->constant_pool_index();
770 case Bytecodes::_invokeinterface:
771 case Bytecodes::_invokehandle:
772 case Bytecodes::_invokespecial:
773 case Bytecodes::_invokestatic:
774 case Bytecodes::_invokevirtual:
775 case Bytecodes::_fast_invokevfinal: // Bytecode interpreter uses this
776 return resolved_method_entry_at(index)->constant_pool_index();
777 default:
778 tty->print_cr("Unexpected bytecode: %d", code);
779 ShouldNotReachHere(); // All cases should have been handled
780 return -1;
781 }
782 }
783
784 bool ConstantPool::is_resolved(int index, Bytecodes::Code code) {
785 assert(cache() != nullptr, "'index' is a rewritten index so this class must have been rewritten");
786 switch(code) {
787 case Bytecodes::_invokedynamic:
788 return resolved_indy_entry_at(index)->is_resolved();
789
790 case Bytecodes::_getfield:
791 case Bytecodes::_getstatic:
792 case Bytecodes::_putfield:
793 case Bytecodes::_putstatic:
794 return resolved_field_entry_at(index)->is_resolved(code);
795
796 case Bytecodes::_invokeinterface:
797 case Bytecodes::_invokehandle:
798 case Bytecodes::_invokespecial:
799 case Bytecodes::_invokestatic:
800 case Bytecodes::_invokevirtual:
801 case Bytecodes::_fast_invokevfinal: // Bytecode interpreter uses this
802 return resolved_method_entry_at(index)->is_resolved(code);
803
804 default:
805 fatal("Unexpected bytecode: %s", Bytecodes::name(code));
806 }
807 }
808
809 u2 ConstantPool::uncached_name_and_type_ref_index_at(int cp_index) {
810 if (tag_at(cp_index).has_bootstrap()) {
811 u2 pool_index = bootstrap_name_and_type_ref_index_at(cp_index);
812 assert(tag_at(pool_index).is_name_and_type(), "");
813 return pool_index;
814 }
815 assert(tag_at(cp_index).is_field_or_method(), "Corrupted constant pool");
816 assert(!tag_at(cp_index).has_bootstrap(), "Must be handled above");
817 jint ref_index = *int_at_addr(cp_index);
818 return extract_high_short_from_int(ref_index);
819 }
820
821 u2 ConstantPool::name_and_type_ref_index_at(int index, Bytecodes::Code code) {
822 return uncached_name_and_type_ref_index_at(to_cp_index(index, code));
823 }
824
825 constantTag ConstantPool::tag_ref_at(int which, Bytecodes::Code code) {
826 // which may be either a Constant Pool index or a rewritten index
827 int pool_index = which;
828 assert(cache() != nullptr, "'index' is a rewritten index so this class must have been rewritten");
829 pool_index = to_cp_index(which, code);
830 return tag_at(pool_index);
831 }
832
833 u2 ConstantPool::uncached_klass_ref_index_at(int cp_index) {
834 assert(tag_at(cp_index).is_field_or_method(), "Corrupted constant pool");
835 jint ref_index = *int_at_addr(cp_index);
836 return extract_low_short_from_int(ref_index);
837 }
838
839 u2 ConstantPool::klass_ref_index_at(int index, Bytecodes::Code code) {
840 assert(code != Bytecodes::_invokedynamic,
841 "an invokedynamic instruction does not have a klass");
842 return uncached_klass_ref_index_at(to_cp_index(index, code));
843 }
844
845 void ConstantPool::verify_constant_pool_resolve(const constantPoolHandle& this_cp, Klass* k, TRAPS) {
846 if (!(k->is_instance_klass() || k->is_objArray_klass())) {
847 return; // short cut, typeArray klass is always accessible
848 }
849 Klass* holder = this_cp->pool_holder();
850 LinkResolver::check_klass_accessibility(holder, k, CHECK);
851 }
852
853
854 u2 ConstantPool::name_ref_index_at(int cp_index) {
855 jint ref_index = name_and_type_at(cp_index);
856 return extract_low_short_from_int(ref_index);
857 }
858
859
860 u2 ConstantPool::signature_ref_index_at(int cp_index) {
861 jint ref_index = name_and_type_at(cp_index);
862 return extract_high_short_from_int(ref_index);
863 }
864
865
866 Klass* ConstantPool::klass_ref_at(int which, Bytecodes::Code code, TRAPS) {
867 return klass_at(klass_ref_index_at(which, code), THREAD);
868 }
869
870 Symbol* ConstantPool::klass_name_at(int cp_index) const {
871 return symbol_at(klass_slot_at(cp_index).name_index());
872 }
873
874 Symbol* ConstantPool::klass_ref_at_noresolve(int which, Bytecodes::Code code) {
875 jint ref_index = klass_ref_index_at(which, code);
876 return klass_at_noresolve(ref_index);
877 }
878
879 Symbol* ConstantPool::uncached_klass_ref_at_noresolve(int cp_index) {
880 jint ref_index = uncached_klass_ref_index_at(cp_index);
881 return klass_at_noresolve(ref_index);
882 }
883
884 char* ConstantPool::string_at_noresolve(int cp_index) {
885 return unresolved_string_at(cp_index)->as_C_string();
886 }
887
888 BasicType ConstantPool::basic_type_for_signature_at(int cp_index) const {
889 return Signature::basic_type(symbol_at(cp_index));
890 }
891
892
893 void ConstantPool::resolve_string_constants_impl(const constantPoolHandle& this_cp, TRAPS) {
894 for (int index = 1; index < this_cp->length(); index++) { // Index 0 is unused
895 if (this_cp->tag_at(index).is_string()) {
896 this_cp->string_at(index, CHECK);
897 }
898 }
899 }
900
901 static const char* exception_message(const constantPoolHandle& this_cp, int which, constantTag tag, oop pending_exception) {
902 // Note: caller needs ResourceMark
903
904 // Dig out the detailed message to reuse if possible
905 const char* msg = java_lang_Throwable::message_as_utf8(pending_exception);
906 if (msg != nullptr) {
907 return msg;
908 }
909
910 Symbol* message = nullptr;
911 // Return specific message for the tag
912 switch (tag.value()) {
913 case JVM_CONSTANT_UnresolvedClass:
914 // return the class name in the error message
915 message = this_cp->klass_name_at(which);
916 break;
917 case JVM_CONSTANT_MethodHandle:
918 // return the method handle name in the error message
919 message = this_cp->method_handle_name_ref_at(which);
920 break;
921 case JVM_CONSTANT_MethodType:
922 // return the method type signature in the error message
923 message = this_cp->method_type_signature_at(which);
924 break;
925 case JVM_CONSTANT_Dynamic:
926 // return the name of the condy in the error message
927 message = this_cp->uncached_name_ref_at(which);
928 break;
929 default:
930 ShouldNotReachHere();
931 }
932
933 return message != nullptr ? message->as_C_string() : nullptr;
934 }
935
936 static void add_resolution_error(JavaThread* current, const constantPoolHandle& this_cp, int which,
937 constantTag tag, oop pending_exception) {
938
939 ResourceMark rm(current);
940 Symbol* error = pending_exception->klass()->name();
941 oop cause = java_lang_Throwable::cause(pending_exception);
942
943 // Also dig out the exception cause, if present.
944 Symbol* cause_sym = nullptr;
945 const char* cause_msg = nullptr;
946 if (cause != nullptr && cause != pending_exception) {
947 cause_sym = cause->klass()->name();
948 cause_msg = java_lang_Throwable::message_as_utf8(cause);
949 }
950
951 const char* message = exception_message(this_cp, which, tag, pending_exception);
952 SystemDictionary::add_resolution_error(this_cp, which, error, message, cause_sym, cause_msg);
953 }
954
955
956 void ConstantPool::throw_resolution_error(const constantPoolHandle& this_cp, int which, TRAPS) {
957 ResourceMark rm(THREAD);
958 const char* message = nullptr;
959 Symbol* cause = nullptr;
960 const char* cause_msg = nullptr;
961 Symbol* error = SystemDictionary::find_resolution_error(this_cp, which, &message, &cause, &cause_msg);
962 assert(error != nullptr, "checking");
963
964 CLEAR_PENDING_EXCEPTION;
965 if (message != nullptr) {
966 if (cause != nullptr) {
967 Handle h_cause = Exceptions::new_exception(THREAD, cause, cause_msg);
968 THROW_MSG_CAUSE(error, message, h_cause);
969 } else {
970 THROW_MSG(error, message);
971 }
972 } else {
973 if (cause != nullptr) {
974 Handle h_cause = Exceptions::new_exception(THREAD, cause, cause_msg);
975 THROW_CAUSE(error, h_cause);
976 } else {
977 THROW(error);
978 }
979 }
980 }
981
982 // If resolution for Class, Dynamic constant, MethodHandle or MethodType fails, save the
983 // exception in the resolution error table, so that the same exception is thrown again.
984 void ConstantPool::save_and_throw_exception(const constantPoolHandle& this_cp, int cp_index,
985 constantTag tag, TRAPS) {
986
987 int error_tag = tag.error_value();
988
989 if (!PENDING_EXCEPTION->
990 is_a(vmClasses::LinkageError_klass())) {
991 // Just throw the exception and don't prevent these classes from
992 // being loaded due to virtual machine errors like StackOverflow
993 // and OutOfMemoryError, etc, or if the thread was hit by stop()
994 // Needs clarification to section 5.4.3 of the VM spec (see 6308271)
995 } else if (this_cp->tag_at(cp_index).value() != error_tag) {
996 add_resolution_error(THREAD, this_cp, cp_index, tag, PENDING_EXCEPTION);
997 // CAS in the tag. If a thread beat us to registering this error that's fine.
998 // If another thread resolved the reference, this is a race condition. This
999 // thread may have had a security manager or something temporary.
1000 // This doesn't deterministically get an error. So why do we save this?
1001 // We save this because jvmti can add classes to the bootclass path after
1002 // this error, so it needs to get the same error if the error is first.
1003 jbyte old_tag = Atomic::cmpxchg((jbyte*)this_cp->tag_addr_at(cp_index),
1004 (jbyte)tag.value(),
1005 (jbyte)error_tag);
1006 if (old_tag != error_tag && old_tag != tag.value()) {
1007 // MethodHandles and MethodType doesn't change to resolved version.
1008 assert(this_cp->tag_at(cp_index).is_klass(), "Wrong tag value");
1009 // Forget the exception and use the resolved class.
1010 CLEAR_PENDING_EXCEPTION;
1011 }
1012 } else {
1013 // some other thread put this in error state
1014 throw_resolution_error(this_cp, cp_index, CHECK);
1015 }
1016 }
1017
1018 constantTag ConstantPool::constant_tag_at(int cp_index) {
1019 constantTag tag = tag_at(cp_index);
1020 if (tag.is_dynamic_constant()) {
1021 BasicType bt = basic_type_for_constant_at(cp_index);
1022 return constantTag(constantTag::type2tag(bt));
1023 }
1024 return tag;
1025 }
1026
1027 BasicType ConstantPool::basic_type_for_constant_at(int cp_index) {
1028 constantTag tag = tag_at(cp_index);
1029 if (tag.is_dynamic_constant() ||
1030 tag.is_dynamic_constant_in_error()) {
1031 // have to look at the signature for this one
1032 Symbol* constant_type = uncached_signature_ref_at(cp_index);
1033 return Signature::basic_type(constant_type);
1034 }
1035 return tag.basic_type();
1036 }
1037
1038 // Called to resolve constants in the constant pool and return an oop.
1039 // Some constant pool entries cache their resolved oop. This is also
1040 // called to create oops from constants to use in arguments for invokedynamic
1041 oop ConstantPool::resolve_constant_at_impl(const constantPoolHandle& this_cp,
1042 int cp_index, int cache_index,
1043 bool* status_return, TRAPS) {
1044 oop result_oop = nullptr;
1045
1046 if (cache_index == _possible_index_sentinel) {
1047 // It is possible that this constant is one which is cached in the objects.
1048 // We'll do a linear search. This should be OK because this usage is rare.
1049 // FIXME: If bootstrap specifiers stress this code, consider putting in
1050 // a reverse index. Binary search over a short array should do it.
1051 assert(cp_index > 0, "valid constant pool index");
1052 cache_index = this_cp->cp_to_object_index(cp_index);
1053 }
1054 assert(cache_index == _no_index_sentinel || cache_index >= 0, "");
1055 assert(cp_index == _no_index_sentinel || cp_index >= 0, "");
1056
1057 if (cache_index >= 0) {
1058 result_oop = this_cp->resolved_reference_at(cache_index);
1059 if (result_oop != nullptr) {
1060 if (result_oop == Universe::the_null_sentinel()) {
1061 DEBUG_ONLY(int temp_index = (cp_index >= 0 ? cp_index : this_cp->object_to_cp_index(cache_index)));
1062 assert(this_cp->tag_at(temp_index).is_dynamic_constant(), "only condy uses the null sentinel");
1063 result_oop = nullptr;
1064 }
1065 if (status_return != nullptr) (*status_return) = true;
1066 return result_oop;
1067 // That was easy...
1068 }
1069 cp_index = this_cp->object_to_cp_index(cache_index);
1070 }
1071
1072 jvalue prim_value; // temp used only in a few cases below
1073
1074 constantTag tag = this_cp->tag_at(cp_index);
1075
1076 if (status_return != nullptr) {
1077 // don't trigger resolution if the constant might need it
1078 switch (tag.value()) {
1079 case JVM_CONSTANT_Class:
1080 {
1081 CPKlassSlot kslot = this_cp->klass_slot_at(cp_index);
1082 int resolved_klass_index = kslot.resolved_klass_index();
1083 if (this_cp->resolved_klasses()->at(resolved_klass_index) == nullptr) {
1084 (*status_return) = false;
1085 return nullptr;
1086 }
1087 // the klass is waiting in the CP; go get it
1088 break;
1089 }
1090 case JVM_CONSTANT_String:
1091 case JVM_CONSTANT_Integer:
1092 case JVM_CONSTANT_Float:
1093 case JVM_CONSTANT_Long:
1094 case JVM_CONSTANT_Double:
1095 // these guys trigger OOM at worst
1096 break;
1097 default:
1098 (*status_return) = false;
1099 return nullptr;
1100 }
1101 // from now on there is either success or an OOME
1102 (*status_return) = true;
1103 }
1104
1105 switch (tag.value()) {
1106
1107 case JVM_CONSTANT_UnresolvedClass:
1108 case JVM_CONSTANT_Class:
1109 {
1110 assert(cache_index == _no_index_sentinel, "should not have been set");
1111 Klass* resolved = klass_at_impl(this_cp, cp_index, CHECK_NULL);
1112 // ldc wants the java mirror.
1113 result_oop = resolved->java_mirror();
1114 break;
1115 }
1116
1117 case JVM_CONSTANT_Dynamic:
1118 { PerfTraceTimedEvent timer(ClassLoader::perf_resolve_invokedynamic_time(),
1119 ClassLoader::perf_resolve_invokedynamic_count());
1120
1121 // Resolve the Dynamically-Computed constant to invoke the BSM in order to obtain the resulting oop.
1122 BootstrapInfo bootstrap_specifier(this_cp, cp_index);
1123
1124 // The initial step in resolving an unresolved symbolic reference to a
1125 // dynamically-computed constant is to resolve the symbolic reference to a
1126 // method handle which will be the bootstrap method for the dynamically-computed
1127 // constant. If resolution of the java.lang.invoke.MethodHandle for the bootstrap
1128 // method fails, then a MethodHandleInError is stored at the corresponding
1129 // bootstrap method's CP index for the CONSTANT_MethodHandle_info. No need to
1130 // set a DynamicConstantInError here since any subsequent use of this
1131 // bootstrap method will encounter the resolution of MethodHandleInError.
1132 // Both the first, (resolution of the BSM and its static arguments), and the second tasks,
1133 // (invocation of the BSM), of JVMS Section 5.4.3.6 occur within invoke_bootstrap_method()
1134 // for the bootstrap_specifier created above.
1135 SystemDictionary::invoke_bootstrap_method(bootstrap_specifier, THREAD);
1136 Exceptions::wrap_dynamic_exception(/* is_indy */ false, THREAD);
1137 if (HAS_PENDING_EXCEPTION) {
1138 // Resolution failure of the dynamically-computed constant, save_and_throw_exception
1139 // will check for a LinkageError and store a DynamicConstantInError.
1140 save_and_throw_exception(this_cp, cp_index, tag, CHECK_NULL);
1141 }
1142 result_oop = bootstrap_specifier.resolved_value()();
1143 BasicType type = Signature::basic_type(bootstrap_specifier.signature());
1144 if (!is_reference_type(type)) {
1145 // Make sure the primitive value is properly boxed.
1146 // This is a JDK responsibility.
1147 const char* fail = nullptr;
1148 if (result_oop == nullptr) {
1149 fail = "null result instead of box";
1150 } else if (!is_java_primitive(type)) {
1151 // FIXME: support value types via unboxing
1152 fail = "can only handle references and primitives";
1153 } else if (!java_lang_boxing_object::is_instance(result_oop, type)) {
1154 fail = "primitive is not properly boxed";
1155 }
1156 if (fail != nullptr) {
1157 // Since this exception is not a LinkageError, throw exception
1158 // but do not save a DynamicInError resolution result.
1159 // See section 5.4.3 of the VM spec.
1160 THROW_MSG_NULL(vmSymbols::java_lang_InternalError(), fail);
1161 }
1162 }
1163
1164 LogTarget(Debug, methodhandles, condy) lt_condy;
1165 if (lt_condy.is_enabled()) {
1166 LogStream ls(lt_condy);
1167 bootstrap_specifier.print_msg_on(&ls, "resolve_constant_at_impl");
1168 }
1169 break;
1170 }
1171
1172 case JVM_CONSTANT_String:
1173 assert(cache_index != _no_index_sentinel, "should have been set");
1174 result_oop = string_at_impl(this_cp, cp_index, cache_index, CHECK_NULL);
1175 break;
1176
1177 case JVM_CONSTANT_MethodHandle:
1178 { PerfTraceTimedEvent timer(ClassLoader::perf_resolve_method_handle_time(),
1179 ClassLoader::perf_resolve_method_handle_count());
1180
1181 int ref_kind = this_cp->method_handle_ref_kind_at(cp_index);
1182 int callee_index = this_cp->method_handle_klass_index_at(cp_index);
1183 Symbol* name = this_cp->method_handle_name_ref_at(cp_index);
1184 Symbol* signature = this_cp->method_handle_signature_ref_at(cp_index);
1185 constantTag m_tag = this_cp->tag_at(this_cp->method_handle_index_at(cp_index));
1186 { ResourceMark rm(THREAD);
1187 log_debug(class, resolve)("resolve JVM_CONSTANT_MethodHandle:%d [%d/%d/%d] %s.%s",
1188 ref_kind, cp_index, this_cp->method_handle_index_at(cp_index),
1189 callee_index, name->as_C_string(), signature->as_C_string());
1190 }
1191
1192 Klass* callee = klass_at_impl(this_cp, callee_index, THREAD);
1193 if (HAS_PENDING_EXCEPTION) {
1194 save_and_throw_exception(this_cp, cp_index, tag, CHECK_NULL);
1195 }
1196
1197 // Check constant pool method consistency
1198 if ((callee->is_interface() && m_tag.is_method()) ||
1199 (!callee->is_interface() && m_tag.is_interface_method())) {
1200 ResourceMark rm(THREAD);
1201 stringStream ss;
1202 ss.print("Inconsistent constant pool data in classfile for class %s. "
1203 "Method '", callee->name()->as_C_string());
1204 signature->print_as_signature_external_return_type(&ss);
1205 ss.print(" %s(", name->as_C_string());
1206 signature->print_as_signature_external_parameters(&ss);
1207 ss.print(")' at index %d is %s and should be %s",
1208 cp_index,
1209 callee->is_interface() ? "CONSTANT_MethodRef" : "CONSTANT_InterfaceMethodRef",
1210 callee->is_interface() ? "CONSTANT_InterfaceMethodRef" : "CONSTANT_MethodRef");
1211 Exceptions::fthrow(THREAD_AND_LOCATION, vmSymbols::java_lang_IncompatibleClassChangeError(), "%s", ss.as_string());
1212 save_and_throw_exception(this_cp, cp_index, tag, CHECK_NULL);
1213 }
1214
1215 Klass* klass = this_cp->pool_holder();
1216 HandleMark hm(THREAD);
1217 Handle value = SystemDictionary::link_method_handle_constant(klass, ref_kind,
1218 callee, name, signature,
1219 THREAD);
1220 if (HAS_PENDING_EXCEPTION) {
1221 save_and_throw_exception(this_cp, cp_index, tag, CHECK_NULL);
1222 }
1223 result_oop = value();
1224 break;
1225 }
1226
1227 case JVM_CONSTANT_MethodType:
1228 { PerfTraceTimedEvent timer(ClassLoader::perf_resolve_method_type_time(),
1229 ClassLoader::perf_resolve_method_type_count());
1230
1231 Symbol* signature = this_cp->method_type_signature_at(cp_index);
1232 { ResourceMark rm(THREAD);
1233 log_debug(class, resolve)("resolve JVM_CONSTANT_MethodType [%d/%d] %s",
1234 cp_index, this_cp->method_type_index_at(cp_index),
1235 signature->as_C_string());
1236 }
1237 Klass* klass = this_cp->pool_holder();
1238 HandleMark hm(THREAD);
1239 Handle value = SystemDictionary::find_method_handle_type(signature, klass, THREAD);
1240 result_oop = value();
1241 if (HAS_PENDING_EXCEPTION) {
1242 save_and_throw_exception(this_cp, cp_index, tag, CHECK_NULL);
1243 }
1244 break;
1245 }
1246
1247 case JVM_CONSTANT_Integer:
1248 assert(cache_index == _no_index_sentinel, "should not have been set");
1249 prim_value.i = this_cp->int_at(cp_index);
1250 result_oop = java_lang_boxing_object::create(T_INT, &prim_value, CHECK_NULL);
1251 break;
1252
1253 case JVM_CONSTANT_Float:
1254 assert(cache_index == _no_index_sentinel, "should not have been set");
1255 prim_value.f = this_cp->float_at(cp_index);
1256 result_oop = java_lang_boxing_object::create(T_FLOAT, &prim_value, CHECK_NULL);
1257 break;
1258
1259 case JVM_CONSTANT_Long:
1260 assert(cache_index == _no_index_sentinel, "should not have been set");
1261 prim_value.j = this_cp->long_at(cp_index);
1262 result_oop = java_lang_boxing_object::create(T_LONG, &prim_value, CHECK_NULL);
1263 break;
1264
1265 case JVM_CONSTANT_Double:
1266 assert(cache_index == _no_index_sentinel, "should not have been set");
1267 prim_value.d = this_cp->double_at(cp_index);
1268 result_oop = java_lang_boxing_object::create(T_DOUBLE, &prim_value, CHECK_NULL);
1269 break;
1270
1271 case JVM_CONSTANT_UnresolvedClassInError:
1272 case JVM_CONSTANT_DynamicInError:
1273 case JVM_CONSTANT_MethodHandleInError:
1274 case JVM_CONSTANT_MethodTypeInError:
1275 throw_resolution_error(this_cp, cp_index, CHECK_NULL);
1276 break;
1277
1278 default:
1279 fatal("unexpected constant tag at CP %p[%d/%d] = %d", this_cp(), cp_index, cache_index, tag.value());
1280 break;
1281 }
1282
1283 if (cache_index >= 0) {
1284 // Benign race condition: resolved_references may already be filled in.
1285 // The important thing here is that all threads pick up the same result.
1286 // It doesn't matter which racing thread wins, as long as only one
1287 // result is used by all threads, and all future queries.
1288 oop new_result = (result_oop == nullptr ? Universe::the_null_sentinel() : result_oop);
1289 oop old_result = this_cp->set_resolved_reference_at(cache_index, new_result);
1290 if (old_result == nullptr) {
1291 return result_oop; // was installed
1292 } else {
1293 // Return the winning thread's result. This can be different than
1294 // the result here for MethodHandles.
1295 if (old_result == Universe::the_null_sentinel())
1296 old_result = nullptr;
1297 return old_result;
1298 }
1299 } else {
1300 assert(result_oop != Universe::the_null_sentinel(), "");
1301 return result_oop;
1302 }
1303 }
1304
1305 oop ConstantPool::uncached_string_at(int cp_index, TRAPS) {
1306 Symbol* sym = unresolved_string_at(cp_index);
1307 oop str = StringTable::intern(sym, CHECK_(nullptr));
1308 assert(java_lang_String::is_instance(str), "must be string");
1309 return str;
1310 }
1311
1312 void ConstantPool::copy_bootstrap_arguments_at_impl(const constantPoolHandle& this_cp, int cp_index,
1313 int start_arg, int end_arg,
1314 objArrayHandle info, int pos,
1315 bool must_resolve, Handle if_not_available,
1316 TRAPS) {
1317 int limit = pos + end_arg - start_arg;
1318 // checks: cp_index in range [0..this_cp->length),
1319 // tag at cp_index, start..end in range [0..this_cp->bootstrap_argument_count],
1320 // info array non-null, pos..limit in [0..info.length]
1321 if ((0 >= cp_index || cp_index >= this_cp->length()) ||
1322 !(this_cp->tag_at(cp_index).is_invoke_dynamic() ||
1323 this_cp->tag_at(cp_index).is_dynamic_constant()) ||
1324 (0 > start_arg || start_arg > end_arg) ||
1325 (end_arg > this_cp->bootstrap_argument_count_at(cp_index)) ||
1326 (0 > pos || pos > limit) ||
1327 (info.is_null() || limit > info->length())) {
1328 // An index or something else went wrong; throw an error.
1329 // Since this is an internal API, we don't expect this,
1330 // so we don't bother to craft a nice message.
1331 THROW_MSG(vmSymbols::java_lang_LinkageError(), "bad BSM argument access");
1332 }
1333 // now we can loop safely
1334 int info_i = pos;
1335 for (int i = start_arg; i < end_arg; i++) {
1336 int arg_index = this_cp->bootstrap_argument_index_at(cp_index, i);
1337 oop arg_oop;
1338 if (must_resolve) {
1339 arg_oop = this_cp->resolve_possibly_cached_constant_at(arg_index, CHECK);
1340 } else {
1341 bool found_it = false;
1342 arg_oop = this_cp->find_cached_constant_at(arg_index, found_it, CHECK);
1343 if (!found_it) arg_oop = if_not_available();
1344 }
1345 info->obj_at_put(info_i++, arg_oop);
1346 }
1347 }
1348
1349 oop ConstantPool::string_at_impl(const constantPoolHandle& this_cp, int cp_index, int obj_index, TRAPS) {
1350 // If the string has already been interned, this entry will be non-null
1351 oop str = this_cp->resolved_reference_at(obj_index);
1352 assert(str != Universe::the_null_sentinel(), "");
1353 if (str != nullptr) return str;
1354 Symbol* sym = this_cp->unresolved_string_at(cp_index);
1355 str = StringTable::intern(sym, CHECK_(nullptr));
1356 this_cp->string_at_put(obj_index, str);
1357 assert(java_lang_String::is_instance(str), "must be string");
1358 return str;
1359 }
1360
1361
1362 bool ConstantPool::klass_name_at_matches(const InstanceKlass* k, int cp_index) {
1363 // Names are interned, so we can compare Symbol*s directly
1364 Symbol* cp_name = klass_name_at(cp_index);
1365 return (cp_name == k->name());
1366 }
1367
1368
1369 // Iterate over symbols and decrement ones which are Symbol*s
1370 // This is done during GC.
1371 // Only decrement the UTF8 symbols. Strings point to
1372 // these symbols but didn't increment the reference count.
1373 void ConstantPool::unreference_symbols() {
1374 for (int index = 1; index < length(); index++) { // Index 0 is unused
1375 constantTag tag = tag_at(index);
1376 if (tag.is_symbol()) {
1377 symbol_at(index)->decrement_refcount();
1378 }
1379 }
1380 }
1381
1382
1383 // Compare this constant pool's entry at index1 to the constant pool
1384 // cp2's entry at index2.
1385 bool ConstantPool::compare_entry_to(int index1, const constantPoolHandle& cp2,
1386 int index2) {
1387
1388 // The error tags are equivalent to non-error tags when comparing
1389 jbyte t1 = tag_at(index1).non_error_value();
1390 jbyte t2 = cp2->tag_at(index2).non_error_value();
1391
1392 // Some classes are pre-resolved (like Throwable) which may lead to
1393 // consider it as a different entry. We then revert them back temporarily
1394 // to ensure proper comparison.
1395 if (t1 == JVM_CONSTANT_Class) {
1396 t1 = JVM_CONSTANT_UnresolvedClass;
1397 }
1398 if (t2 == JVM_CONSTANT_Class) {
1399 t2 = JVM_CONSTANT_UnresolvedClass;
1400 }
1401
1402 if (t1 != t2) {
1403 // Not the same entry type so there is nothing else to check. Note
1404 // that this style of checking will consider resolved/unresolved
1405 // class pairs as different.
1406 // From the ConstantPool* API point of view, this is correct
1407 // behavior. See VM_RedefineClasses::merge_constant_pools() to see how this
1408 // plays out in the context of ConstantPool* merging.
1409 return false;
1410 }
1411
1412 switch (t1) {
1413 case JVM_CONSTANT_ClassIndex:
1414 {
1415 int recur1 = klass_index_at(index1);
1416 int recur2 = cp2->klass_index_at(index2);
1417 if (compare_entry_to(recur1, cp2, recur2)) {
1418 return true;
1419 }
1420 } break;
1421
1422 case JVM_CONSTANT_Double:
1423 {
1424 jdouble d1 = double_at(index1);
1425 jdouble d2 = cp2->double_at(index2);
1426 if (d1 == d2) {
1427 return true;
1428 }
1429 } break;
1430
1431 case JVM_CONSTANT_Fieldref:
1432 case JVM_CONSTANT_InterfaceMethodref:
1433 case JVM_CONSTANT_Methodref:
1434 {
1435 int recur1 = uncached_klass_ref_index_at(index1);
1436 int recur2 = cp2->uncached_klass_ref_index_at(index2);
1437 bool match = compare_entry_to(recur1, cp2, recur2);
1438 if (match) {
1439 recur1 = uncached_name_and_type_ref_index_at(index1);
1440 recur2 = cp2->uncached_name_and_type_ref_index_at(index2);
1441 if (compare_entry_to(recur1, cp2, recur2)) {
1442 return true;
1443 }
1444 }
1445 } break;
1446
1447 case JVM_CONSTANT_Float:
1448 {
1449 jfloat f1 = float_at(index1);
1450 jfloat f2 = cp2->float_at(index2);
1451 if (f1 == f2) {
1452 return true;
1453 }
1454 } break;
1455
1456 case JVM_CONSTANT_Integer:
1457 {
1458 jint i1 = int_at(index1);
1459 jint i2 = cp2->int_at(index2);
1460 if (i1 == i2) {
1461 return true;
1462 }
1463 } break;
1464
1465 case JVM_CONSTANT_Long:
1466 {
1467 jlong l1 = long_at(index1);
1468 jlong l2 = cp2->long_at(index2);
1469 if (l1 == l2) {
1470 return true;
1471 }
1472 } break;
1473
1474 case JVM_CONSTANT_NameAndType:
1475 {
1476 int recur1 = name_ref_index_at(index1);
1477 int recur2 = cp2->name_ref_index_at(index2);
1478 if (compare_entry_to(recur1, cp2, recur2)) {
1479 recur1 = signature_ref_index_at(index1);
1480 recur2 = cp2->signature_ref_index_at(index2);
1481 if (compare_entry_to(recur1, cp2, recur2)) {
1482 return true;
1483 }
1484 }
1485 } break;
1486
1487 case JVM_CONSTANT_StringIndex:
1488 {
1489 int recur1 = string_index_at(index1);
1490 int recur2 = cp2->string_index_at(index2);
1491 if (compare_entry_to(recur1, cp2, recur2)) {
1492 return true;
1493 }
1494 } break;
1495
1496 case JVM_CONSTANT_UnresolvedClass:
1497 {
1498 Symbol* k1 = klass_name_at(index1);
1499 Symbol* k2 = cp2->klass_name_at(index2);
1500 if (k1 == k2) {
1501 return true;
1502 }
1503 } break;
1504
1505 case JVM_CONSTANT_MethodType:
1506 {
1507 int k1 = method_type_index_at(index1);
1508 int k2 = cp2->method_type_index_at(index2);
1509 if (compare_entry_to(k1, cp2, k2)) {
1510 return true;
1511 }
1512 } break;
1513
1514 case JVM_CONSTANT_MethodHandle:
1515 {
1516 int k1 = method_handle_ref_kind_at(index1);
1517 int k2 = cp2->method_handle_ref_kind_at(index2);
1518 if (k1 == k2) {
1519 int i1 = method_handle_index_at(index1);
1520 int i2 = cp2->method_handle_index_at(index2);
1521 if (compare_entry_to(i1, cp2, i2)) {
1522 return true;
1523 }
1524 }
1525 } break;
1526
1527 case JVM_CONSTANT_Dynamic:
1528 {
1529 int k1 = bootstrap_name_and_type_ref_index_at(index1);
1530 int k2 = cp2->bootstrap_name_and_type_ref_index_at(index2);
1531 int i1 = bootstrap_methods_attribute_index(index1);
1532 int i2 = cp2->bootstrap_methods_attribute_index(index2);
1533 bool match_entry = compare_entry_to(k1, cp2, k2);
1534 bool match_operand = compare_operand_to(i1, cp2, i2);
1535 return (match_entry && match_operand);
1536 } break;
1537
1538 case JVM_CONSTANT_InvokeDynamic:
1539 {
1540 int k1 = bootstrap_name_and_type_ref_index_at(index1);
1541 int k2 = cp2->bootstrap_name_and_type_ref_index_at(index2);
1542 int i1 = bootstrap_methods_attribute_index(index1);
1543 int i2 = cp2->bootstrap_methods_attribute_index(index2);
1544 bool match_entry = compare_entry_to(k1, cp2, k2);
1545 bool match_operand = compare_operand_to(i1, cp2, i2);
1546 return (match_entry && match_operand);
1547 } break;
1548
1549 case JVM_CONSTANT_String:
1550 {
1551 Symbol* s1 = unresolved_string_at(index1);
1552 Symbol* s2 = cp2->unresolved_string_at(index2);
1553 if (s1 == s2) {
1554 return true;
1555 }
1556 } break;
1557
1558 case JVM_CONSTANT_Utf8:
1559 {
1560 Symbol* s1 = symbol_at(index1);
1561 Symbol* s2 = cp2->symbol_at(index2);
1562 if (s1 == s2) {
1563 return true;
1564 }
1565 } break;
1566
1567 // Invalid is used as the tag for the second constant pool entry
1568 // occupied by JVM_CONSTANT_Double or JVM_CONSTANT_Long. It should
1569 // not be seen by itself.
1570 case JVM_CONSTANT_Invalid: // fall through
1571
1572 default:
1573 ShouldNotReachHere();
1574 break;
1575 }
1576
1577 return false;
1578 } // end compare_entry_to()
1579
1580
1581 // Resize the operands array with delta_len and delta_size.
1582 // Used in RedefineClasses for CP merge.
1583 void ConstantPool::resize_operands(int delta_len, int delta_size, TRAPS) {
1584 int old_len = operand_array_length(operands());
1585 int new_len = old_len + delta_len;
1586 int min_len = (delta_len > 0) ? old_len : new_len;
1587
1588 int old_size = operands()->length();
1589 int new_size = old_size + delta_size;
1590 int min_size = (delta_size > 0) ? old_size : new_size;
1591
1592 ClassLoaderData* loader_data = pool_holder()->class_loader_data();
1593 Array<u2>* new_ops = MetadataFactory::new_array<u2>(loader_data, new_size, CHECK);
1594
1595 // Set index in the resized array for existing elements only
1596 for (int idx = 0; idx < min_len; idx++) {
1597 int offset = operand_offset_at(idx); // offset in original array
1598 operand_offset_at_put(new_ops, idx, offset + 2*delta_len); // offset in resized array
1599 }
1600 // Copy the bootstrap specifiers only
1601 Copy::conjoint_memory_atomic(operands()->adr_at(2*old_len),
1602 new_ops->adr_at(2*new_len),
1603 (min_size - 2*min_len) * sizeof(u2));
1604 // Explicitly deallocate old operands array.
1605 // Note, it is not needed for 7u backport.
1606 if ( operands() != nullptr) { // the safety check
1607 MetadataFactory::free_array<u2>(loader_data, operands());
1608 }
1609 set_operands(new_ops);
1610 } // end resize_operands()
1611
1612
1613 // Extend the operands array with the length and size of the ext_cp operands.
1614 // Used in RedefineClasses for CP merge.
1615 void ConstantPool::extend_operands(const constantPoolHandle& ext_cp, TRAPS) {
1616 int delta_len = operand_array_length(ext_cp->operands());
1617 if (delta_len == 0) {
1618 return; // nothing to do
1619 }
1620 int delta_size = ext_cp->operands()->length();
1621
1622 assert(delta_len > 0 && delta_size > 0, "extended operands array must be bigger");
1623
1624 if (operand_array_length(operands()) == 0) {
1625 ClassLoaderData* loader_data = pool_holder()->class_loader_data();
1626 Array<u2>* new_ops = MetadataFactory::new_array<u2>(loader_data, delta_size, CHECK);
1627 // The first element index defines the offset of second part
1628 operand_offset_at_put(new_ops, 0, 2*delta_len); // offset in new array
1629 set_operands(new_ops);
1630 } else {
1631 resize_operands(delta_len, delta_size, CHECK);
1632 }
1633
1634 } // end extend_operands()
1635
1636
1637 // Shrink the operands array to a smaller array with new_len length.
1638 // Used in RedefineClasses for CP merge.
1639 void ConstantPool::shrink_operands(int new_len, TRAPS) {
1640 int old_len = operand_array_length(operands());
1641 if (new_len == old_len) {
1642 return; // nothing to do
1643 }
1644 assert(new_len < old_len, "shrunken operands array must be smaller");
1645
1646 int free_base = operand_next_offset_at(new_len - 1);
1647 int delta_len = new_len - old_len;
1648 int delta_size = 2*delta_len + free_base - operands()->length();
1649
1650 resize_operands(delta_len, delta_size, CHECK);
1651
1652 } // end shrink_operands()
1653
1654
1655 void ConstantPool::copy_operands(const constantPoolHandle& from_cp,
1656 const constantPoolHandle& to_cp,
1657 TRAPS) {
1658
1659 int from_oplen = operand_array_length(from_cp->operands());
1660 int old_oplen = operand_array_length(to_cp->operands());
1661 if (from_oplen != 0) {
1662 ClassLoaderData* loader_data = to_cp->pool_holder()->class_loader_data();
1663 // append my operands to the target's operands array
1664 if (old_oplen == 0) {
1665 // Can't just reuse from_cp's operand list because of deallocation issues
1666 int len = from_cp->operands()->length();
1667 Array<u2>* new_ops = MetadataFactory::new_array<u2>(loader_data, len, CHECK);
1668 Copy::conjoint_memory_atomic(
1669 from_cp->operands()->adr_at(0), new_ops->adr_at(0), len * sizeof(u2));
1670 to_cp->set_operands(new_ops);
1671 } else {
1672 int old_len = to_cp->operands()->length();
1673 int from_len = from_cp->operands()->length();
1674 int old_off = old_oplen * sizeof(u2);
1675 int from_off = from_oplen * sizeof(u2);
1676 // Use the metaspace for the destination constant pool
1677 Array<u2>* new_operands = MetadataFactory::new_array<u2>(loader_data, old_len + from_len, CHECK);
1678 int fillp = 0, len = 0;
1679 // first part of dest
1680 Copy::conjoint_memory_atomic(to_cp->operands()->adr_at(0),
1681 new_operands->adr_at(fillp),
1682 (len = old_off) * sizeof(u2));
1683 fillp += len;
1684 // first part of src
1685 Copy::conjoint_memory_atomic(from_cp->operands()->adr_at(0),
1686 new_operands->adr_at(fillp),
1687 (len = from_off) * sizeof(u2));
1688 fillp += len;
1689 // second part of dest
1690 Copy::conjoint_memory_atomic(to_cp->operands()->adr_at(old_off),
1691 new_operands->adr_at(fillp),
1692 (len = old_len - old_off) * sizeof(u2));
1693 fillp += len;
1694 // second part of src
1695 Copy::conjoint_memory_atomic(from_cp->operands()->adr_at(from_off),
1696 new_operands->adr_at(fillp),
1697 (len = from_len - from_off) * sizeof(u2));
1698 fillp += len;
1699 assert(fillp == new_operands->length(), "");
1700
1701 // Adjust indexes in the first part of the copied operands array.
1702 for (int j = 0; j < from_oplen; j++) {
1703 int offset = operand_offset_at(new_operands, old_oplen + j);
1704 assert(offset == operand_offset_at(from_cp->operands(), j), "correct copy");
1705 offset += old_len; // every new tuple is preceded by old_len extra u2's
1706 operand_offset_at_put(new_operands, old_oplen + j, offset);
1707 }
1708
1709 // replace target operands array with combined array
1710 to_cp->set_operands(new_operands);
1711 }
1712 }
1713 } // end copy_operands()
1714
1715
1716 // Copy this constant pool's entries at start_i to end_i (inclusive)
1717 // to the constant pool to_cp's entries starting at to_i. A total of
1718 // (end_i - start_i) + 1 entries are copied.
1719 void ConstantPool::copy_cp_to_impl(const constantPoolHandle& from_cp, int start_i, int end_i,
1720 const constantPoolHandle& to_cp, int to_i, TRAPS) {
1721
1722
1723 int dest_cpi = to_i; // leave original alone for debug purposes
1724
1725 for (int src_cpi = start_i; src_cpi <= end_i; /* see loop bottom */ ) {
1726 copy_entry_to(from_cp, src_cpi, to_cp, dest_cpi);
1727
1728 switch (from_cp->tag_at(src_cpi).value()) {
1729 case JVM_CONSTANT_Double:
1730 case JVM_CONSTANT_Long:
1731 // double and long take two constant pool entries
1732 src_cpi += 2;
1733 dest_cpi += 2;
1734 break;
1735
1736 default:
1737 // all others take one constant pool entry
1738 src_cpi++;
1739 dest_cpi++;
1740 break;
1741 }
1742 }
1743 copy_operands(from_cp, to_cp, CHECK);
1744
1745 } // end copy_cp_to_impl()
1746
1747
1748 // Copy this constant pool's entry at from_i to the constant pool
1749 // to_cp's entry at to_i.
1750 void ConstantPool::copy_entry_to(const constantPoolHandle& from_cp, int from_i,
1751 const constantPoolHandle& to_cp, int to_i) {
1752
1753 int tag = from_cp->tag_at(from_i).value();
1754 switch (tag) {
1755 case JVM_CONSTANT_ClassIndex:
1756 {
1757 jint ki = from_cp->klass_index_at(from_i);
1758 to_cp->klass_index_at_put(to_i, ki);
1759 } break;
1760
1761 case JVM_CONSTANT_Double:
1762 {
1763 jdouble d = from_cp->double_at(from_i);
1764 to_cp->double_at_put(to_i, d);
1765 // double takes two constant pool entries so init second entry's tag
1766 to_cp->tag_at_put(to_i + 1, JVM_CONSTANT_Invalid);
1767 } break;
1768
1769 case JVM_CONSTANT_Fieldref:
1770 {
1771 int class_index = from_cp->uncached_klass_ref_index_at(from_i);
1772 int name_and_type_index = from_cp->uncached_name_and_type_ref_index_at(from_i);
1773 to_cp->field_at_put(to_i, class_index, name_and_type_index);
1774 } break;
1775
1776 case JVM_CONSTANT_Float:
1777 {
1778 jfloat f = from_cp->float_at(from_i);
1779 to_cp->float_at_put(to_i, f);
1780 } break;
1781
1782 case JVM_CONSTANT_Integer:
1783 {
1784 jint i = from_cp->int_at(from_i);
1785 to_cp->int_at_put(to_i, i);
1786 } break;
1787
1788 case JVM_CONSTANT_InterfaceMethodref:
1789 {
1790 int class_index = from_cp->uncached_klass_ref_index_at(from_i);
1791 int name_and_type_index = from_cp->uncached_name_and_type_ref_index_at(from_i);
1792 to_cp->interface_method_at_put(to_i, class_index, name_and_type_index);
1793 } break;
1794
1795 case JVM_CONSTANT_Long:
1796 {
1797 jlong l = from_cp->long_at(from_i);
1798 to_cp->long_at_put(to_i, l);
1799 // long takes two constant pool entries so init second entry's tag
1800 to_cp->tag_at_put(to_i + 1, JVM_CONSTANT_Invalid);
1801 } break;
1802
1803 case JVM_CONSTANT_Methodref:
1804 {
1805 int class_index = from_cp->uncached_klass_ref_index_at(from_i);
1806 int name_and_type_index = from_cp->uncached_name_and_type_ref_index_at(from_i);
1807 to_cp->method_at_put(to_i, class_index, name_and_type_index);
1808 } break;
1809
1810 case JVM_CONSTANT_NameAndType:
1811 {
1812 int name_ref_index = from_cp->name_ref_index_at(from_i);
1813 int signature_ref_index = from_cp->signature_ref_index_at(from_i);
1814 to_cp->name_and_type_at_put(to_i, name_ref_index, signature_ref_index);
1815 } break;
1816
1817 case JVM_CONSTANT_StringIndex:
1818 {
1819 jint si = from_cp->string_index_at(from_i);
1820 to_cp->string_index_at_put(to_i, si);
1821 } break;
1822
1823 case JVM_CONSTANT_Class:
1824 case JVM_CONSTANT_UnresolvedClass:
1825 case JVM_CONSTANT_UnresolvedClassInError:
1826 {
1827 // Revert to JVM_CONSTANT_ClassIndex
1828 int name_index = from_cp->klass_slot_at(from_i).name_index();
1829 assert(from_cp->tag_at(name_index).is_symbol(), "sanity");
1830 to_cp->klass_index_at_put(to_i, name_index);
1831 } break;
1832
1833 case JVM_CONSTANT_String:
1834 {
1835 Symbol* s = from_cp->unresolved_string_at(from_i);
1836 to_cp->unresolved_string_at_put(to_i, s);
1837 } break;
1838
1839 case JVM_CONSTANT_Utf8:
1840 {
1841 Symbol* s = from_cp->symbol_at(from_i);
1842 // Need to increase refcount, the old one will be thrown away and deferenced
1843 s->increment_refcount();
1844 to_cp->symbol_at_put(to_i, s);
1845 } break;
1846
1847 case JVM_CONSTANT_MethodType:
1848 case JVM_CONSTANT_MethodTypeInError:
1849 {
1850 jint k = from_cp->method_type_index_at(from_i);
1851 to_cp->method_type_index_at_put(to_i, k);
1852 } break;
1853
1854 case JVM_CONSTANT_MethodHandle:
1855 case JVM_CONSTANT_MethodHandleInError:
1856 {
1857 int k1 = from_cp->method_handle_ref_kind_at(from_i);
1858 int k2 = from_cp->method_handle_index_at(from_i);
1859 to_cp->method_handle_index_at_put(to_i, k1, k2);
1860 } break;
1861
1862 case JVM_CONSTANT_Dynamic:
1863 case JVM_CONSTANT_DynamicInError:
1864 {
1865 int k1 = from_cp->bootstrap_methods_attribute_index(from_i);
1866 int k2 = from_cp->bootstrap_name_and_type_ref_index_at(from_i);
1867 k1 += operand_array_length(to_cp->operands()); // to_cp might already have operands
1868 to_cp->dynamic_constant_at_put(to_i, k1, k2);
1869 } break;
1870
1871 case JVM_CONSTANT_InvokeDynamic:
1872 {
1873 int k1 = from_cp->bootstrap_methods_attribute_index(from_i);
1874 int k2 = from_cp->bootstrap_name_and_type_ref_index_at(from_i);
1875 k1 += operand_array_length(to_cp->operands()); // to_cp might already have operands
1876 to_cp->invoke_dynamic_at_put(to_i, k1, k2);
1877 } break;
1878
1879 // Invalid is used as the tag for the second constant pool entry
1880 // occupied by JVM_CONSTANT_Double or JVM_CONSTANT_Long. It should
1881 // not be seen by itself.
1882 case JVM_CONSTANT_Invalid: // fall through
1883
1884 default:
1885 {
1886 ShouldNotReachHere();
1887 } break;
1888 }
1889 } // end copy_entry_to()
1890
1891 // Search constant pool search_cp for an entry that matches this
1892 // constant pool's entry at pattern_i. Returns the index of a
1893 // matching entry or zero (0) if there is no matching entry.
1894 int ConstantPool::find_matching_entry(int pattern_i,
1895 const constantPoolHandle& search_cp) {
1896
1897 // index zero (0) is not used
1898 for (int i = 1; i < search_cp->length(); i++) {
1899 bool found = compare_entry_to(pattern_i, search_cp, i);
1900 if (found) {
1901 return i;
1902 }
1903 }
1904
1905 return 0; // entry not found; return unused index zero (0)
1906 } // end find_matching_entry()
1907
1908
1909 // Compare this constant pool's bootstrap specifier at idx1 to the constant pool
1910 // cp2's bootstrap specifier at idx2.
1911 bool ConstantPool::compare_operand_to(int idx1, const constantPoolHandle& cp2, int idx2) {
1912 int k1 = operand_bootstrap_method_ref_index_at(idx1);
1913 int k2 = cp2->operand_bootstrap_method_ref_index_at(idx2);
1914 bool match = compare_entry_to(k1, cp2, k2);
1915
1916 if (!match) {
1917 return false;
1918 }
1919 int argc = operand_argument_count_at(idx1);
1920 if (argc == cp2->operand_argument_count_at(idx2)) {
1921 for (int j = 0; j < argc; j++) {
1922 k1 = operand_argument_index_at(idx1, j);
1923 k2 = cp2->operand_argument_index_at(idx2, j);
1924 match = compare_entry_to(k1, cp2, k2);
1925 if (!match) {
1926 return false;
1927 }
1928 }
1929 return true; // got through loop; all elements equal
1930 }
1931 return false;
1932 } // end compare_operand_to()
1933
1934 // Search constant pool search_cp for a bootstrap specifier that matches
1935 // this constant pool's bootstrap specifier data at pattern_i index.
1936 // Return the index of a matching bootstrap attribute record or (-1) if there is no match.
1937 int ConstantPool::find_matching_operand(int pattern_i,
1938 const constantPoolHandle& search_cp, int search_len) {
1939 for (int i = 0; i < search_len; i++) {
1940 bool found = compare_operand_to(pattern_i, search_cp, i);
1941 if (found) {
1942 return i;
1943 }
1944 }
1945 return -1; // bootstrap specifier data not found; return unused index (-1)
1946 } // end find_matching_operand()
1947
1948
1949 #ifndef PRODUCT
1950
1951 const char* ConstantPool::printable_name_at(int cp_index) {
1952
1953 constantTag tag = tag_at(cp_index);
1954
1955 if (tag.is_string()) {
1956 return string_at_noresolve(cp_index);
1957 } else if (tag.is_klass() || tag.is_unresolved_klass()) {
1958 return klass_name_at(cp_index)->as_C_string();
1959 } else if (tag.is_symbol()) {
1960 return symbol_at(cp_index)->as_C_string();
1961 }
1962 return "";
1963 }
1964
1965 #endif // PRODUCT
1966
1967
1968 // JVMTI GetConstantPool support
1969
1970 // For debugging of constant pool
1971 const bool debug_cpool = false;
1972
1973 #define DBG(code) do { if (debug_cpool) { (code); } } while(0)
1974
1975 static void print_cpool_bytes(jint cnt, u1 *bytes) {
1976 const char* WARN_MSG = "Must not be such entry!";
1977 jint size = 0;
1978 u2 idx1, idx2;
1979
1980 for (jint idx = 1; idx < cnt; idx++) {
1981 jint ent_size = 0;
1982 u1 tag = *bytes++;
1983 size++; // count tag
1984
1985 printf("const #%03d, tag: %02d ", idx, tag);
1986 switch(tag) {
1987 case JVM_CONSTANT_Invalid: {
1988 printf("Invalid");
1989 break;
1990 }
1991 case JVM_CONSTANT_Unicode: {
1992 printf("Unicode %s", WARN_MSG);
1993 break;
1994 }
1995 case JVM_CONSTANT_Utf8: {
1996 u2 len = Bytes::get_Java_u2(bytes);
1997 char str[128];
1998 if (len > 127) {
1999 len = 127;
2000 }
2001 strncpy(str, (char *) (bytes+2), len);
2002 str[len] = '\0';
2003 printf("Utf8 \"%s\"", str);
2004 ent_size = 2 + len;
2005 break;
2006 }
2007 case JVM_CONSTANT_Integer: {
2008 u4 val = Bytes::get_Java_u4(bytes);
2009 printf("int %d", *(int *) &val);
2010 ent_size = 4;
2011 break;
2012 }
2013 case JVM_CONSTANT_Float: {
2014 u4 val = Bytes::get_Java_u4(bytes);
2015 printf("float %5.3ff", *(float *) &val);
2016 ent_size = 4;
2017 break;
2018 }
2019 case JVM_CONSTANT_Long: {
2020 u8 val = Bytes::get_Java_u8(bytes);
2021 printf("long " INT64_FORMAT, (int64_t) *(jlong *) &val);
2022 ent_size = 8;
2023 idx++; // Long takes two cpool slots
2024 break;
2025 }
2026 case JVM_CONSTANT_Double: {
2027 u8 val = Bytes::get_Java_u8(bytes);
2028 printf("double %5.3fd", *(jdouble *)&val);
2029 ent_size = 8;
2030 idx++; // Double takes two cpool slots
2031 break;
2032 }
2033 case JVM_CONSTANT_Class: {
2034 idx1 = Bytes::get_Java_u2(bytes);
2035 printf("class #%03d", idx1);
2036 ent_size = 2;
2037 break;
2038 }
2039 case JVM_CONSTANT_String: {
2040 idx1 = Bytes::get_Java_u2(bytes);
2041 printf("String #%03d", idx1);
2042 ent_size = 2;
2043 break;
2044 }
2045 case JVM_CONSTANT_Fieldref: {
2046 idx1 = Bytes::get_Java_u2(bytes);
2047 idx2 = Bytes::get_Java_u2(bytes+2);
2048 printf("Field #%03d, #%03d", (int) idx1, (int) idx2);
2049 ent_size = 4;
2050 break;
2051 }
2052 case JVM_CONSTANT_Methodref: {
2053 idx1 = Bytes::get_Java_u2(bytes);
2054 idx2 = Bytes::get_Java_u2(bytes+2);
2055 printf("Method #%03d, #%03d", idx1, idx2);
2056 ent_size = 4;
2057 break;
2058 }
2059 case JVM_CONSTANT_InterfaceMethodref: {
2060 idx1 = Bytes::get_Java_u2(bytes);
2061 idx2 = Bytes::get_Java_u2(bytes+2);
2062 printf("InterfMethod #%03d, #%03d", idx1, idx2);
2063 ent_size = 4;
2064 break;
2065 }
2066 case JVM_CONSTANT_NameAndType: {
2067 idx1 = Bytes::get_Java_u2(bytes);
2068 idx2 = Bytes::get_Java_u2(bytes+2);
2069 printf("NameAndType #%03d, #%03d", idx1, idx2);
2070 ent_size = 4;
2071 break;
2072 }
2073 case JVM_CONSTANT_ClassIndex: {
2074 printf("ClassIndex %s", WARN_MSG);
2075 break;
2076 }
2077 case JVM_CONSTANT_UnresolvedClass: {
2078 printf("UnresolvedClass: %s", WARN_MSG);
2079 break;
2080 }
2081 case JVM_CONSTANT_UnresolvedClassInError: {
2082 printf("UnresolvedClassInErr: %s", WARN_MSG);
2083 break;
2084 }
2085 case JVM_CONSTANT_StringIndex: {
2086 printf("StringIndex: %s", WARN_MSG);
2087 break;
2088 }
2089 }
2090 printf(";\n");
2091 bytes += ent_size;
2092 size += ent_size;
2093 }
2094 printf("Cpool size: %d\n", size);
2095 fflush(nullptr);
2096 return;
2097 } /* end print_cpool_bytes */
2098
2099
2100 // Returns size of constant pool entry.
2101 jint ConstantPool::cpool_entry_size(jint idx) {
2102 switch(tag_at(idx).value()) {
2103 case JVM_CONSTANT_Invalid:
2104 case JVM_CONSTANT_Unicode:
2105 return 1;
2106
2107 case JVM_CONSTANT_Utf8:
2108 return 3 + symbol_at(idx)->utf8_length();
2109
2110 case JVM_CONSTANT_Class:
2111 case JVM_CONSTANT_String:
2112 case JVM_CONSTANT_ClassIndex:
2113 case JVM_CONSTANT_UnresolvedClass:
2114 case JVM_CONSTANT_UnresolvedClassInError:
2115 case JVM_CONSTANT_StringIndex:
2116 case JVM_CONSTANT_MethodType:
2117 case JVM_CONSTANT_MethodTypeInError:
2118 return 3;
2119
2120 case JVM_CONSTANT_MethodHandle:
2121 case JVM_CONSTANT_MethodHandleInError:
2122 return 4; //tag, ref_kind, ref_index
2123
2124 case JVM_CONSTANT_Integer:
2125 case JVM_CONSTANT_Float:
2126 case JVM_CONSTANT_Fieldref:
2127 case JVM_CONSTANT_Methodref:
2128 case JVM_CONSTANT_InterfaceMethodref:
2129 case JVM_CONSTANT_NameAndType:
2130 return 5;
2131
2132 case JVM_CONSTANT_Dynamic:
2133 case JVM_CONSTANT_DynamicInError:
2134 case JVM_CONSTANT_InvokeDynamic:
2135 // u1 tag, u2 bsm, u2 nt
2136 return 5;
2137
2138 case JVM_CONSTANT_Long:
2139 case JVM_CONSTANT_Double:
2140 return 9;
2141 }
2142 assert(false, "cpool_entry_size: Invalid constant pool entry tag");
2143 return 1;
2144 } /* end cpool_entry_size */
2145
2146
2147 // SymbolHash is used to find a constant pool index from a string.
2148 // This function fills in SymbolHashs, one for utf8s and one for
2149 // class names, returns size of the cpool raw bytes.
2150 jint ConstantPool::hash_entries_to(SymbolHash *symmap,
2151 SymbolHash *classmap) {
2152 jint size = 0;
2153
2154 for (u2 idx = 1; idx < length(); idx++) {
2155 u2 tag = tag_at(idx).value();
2156 size += cpool_entry_size(idx);
2157
2158 switch(tag) {
2159 case JVM_CONSTANT_Utf8: {
2160 Symbol* sym = symbol_at(idx);
2161 symmap->add_if_absent(sym, idx);
2162 DBG(printf("adding symbol entry %s = %d\n", sym->as_utf8(), idx));
2163 break;
2164 }
2165 case JVM_CONSTANT_Class:
2166 case JVM_CONSTANT_UnresolvedClass:
2167 case JVM_CONSTANT_UnresolvedClassInError: {
2168 Symbol* sym = klass_name_at(idx);
2169 classmap->add_if_absent(sym, idx);
2170 DBG(printf("adding class entry %s = %d\n", sym->as_utf8(), idx));
2171 break;
2172 }
2173 case JVM_CONSTANT_Long:
2174 case JVM_CONSTANT_Double: {
2175 idx++; // Both Long and Double take two cpool slots
2176 break;
2177 }
2178 }
2179 }
2180 return size;
2181 } /* end hash_utf8_entries_to */
2182
2183
2184 // Copy cpool bytes.
2185 // Returns:
2186 // 0, in case of OutOfMemoryError
2187 // -1, in case of internal error
2188 // > 0, count of the raw cpool bytes that have been copied
2189 int ConstantPool::copy_cpool_bytes(int cpool_size,
2190 SymbolHash* tbl,
2191 unsigned char *bytes) {
2192 u2 idx1, idx2;
2193 jint size = 0;
2194 jint cnt = length();
2195 unsigned char *start_bytes = bytes;
2196
2197 for (jint idx = 1; idx < cnt; idx++) {
2198 u1 tag = tag_at(idx).value();
2199 jint ent_size = cpool_entry_size(idx);
2200
2201 assert(size + ent_size <= cpool_size, "Size mismatch");
2202
2203 *bytes = tag;
2204 DBG(printf("#%03hd tag=%03hd, ", (short)idx, (short)tag));
2205 switch(tag) {
2206 case JVM_CONSTANT_Invalid: {
2207 DBG(printf("JVM_CONSTANT_Invalid"));
2208 break;
2209 }
2210 case JVM_CONSTANT_Unicode: {
2211 assert(false, "Wrong constant pool tag: JVM_CONSTANT_Unicode");
2212 DBG(printf("JVM_CONSTANT_Unicode"));
2213 break;
2214 }
2215 case JVM_CONSTANT_Utf8: {
2216 Symbol* sym = symbol_at(idx);
2217 char* str = sym->as_utf8();
2218 // Warning! It's crashing on x86 with len = sym->utf8_length()
2219 int len = (int) strlen(str);
2220 Bytes::put_Java_u2((address) (bytes+1), (u2) len);
2221 for (int i = 0; i < len; i++) {
2222 bytes[3+i] = (u1) str[i];
2223 }
2224 DBG(printf("JVM_CONSTANT_Utf8: %s ", str));
2225 break;
2226 }
2227 case JVM_CONSTANT_Integer: {
2228 jint val = int_at(idx);
2229 Bytes::put_Java_u4((address) (bytes+1), *(u4*)&val);
2230 break;
2231 }
2232 case JVM_CONSTANT_Float: {
2233 jfloat val = float_at(idx);
2234 Bytes::put_Java_u4((address) (bytes+1), *(u4*)&val);
2235 break;
2236 }
2237 case JVM_CONSTANT_Long: {
2238 jlong val = long_at(idx);
2239 Bytes::put_Java_u8((address) (bytes+1), *(u8*)&val);
2240 idx++; // Long takes two cpool slots
2241 break;
2242 }
2243 case JVM_CONSTANT_Double: {
2244 jdouble val = double_at(idx);
2245 Bytes::put_Java_u8((address) (bytes+1), *(u8*)&val);
2246 idx++; // Double takes two cpool slots
2247 break;
2248 }
2249 case JVM_CONSTANT_Class:
2250 case JVM_CONSTANT_UnresolvedClass:
2251 case JVM_CONSTANT_UnresolvedClassInError: {
2252 *bytes = JVM_CONSTANT_Class;
2253 Symbol* sym = klass_name_at(idx);
2254 idx1 = tbl->symbol_to_value(sym);
2255 assert(idx1 != 0, "Have not found a hashtable entry");
2256 Bytes::put_Java_u2((address) (bytes+1), idx1);
2257 DBG(printf("JVM_CONSTANT_Class: idx=#%03hd, %s", idx1, sym->as_utf8()));
2258 break;
2259 }
2260 case JVM_CONSTANT_String: {
2261 *bytes = JVM_CONSTANT_String;
2262 Symbol* sym = unresolved_string_at(idx);
2263 idx1 = tbl->symbol_to_value(sym);
2264 assert(idx1 != 0, "Have not found a hashtable entry");
2265 Bytes::put_Java_u2((address) (bytes+1), idx1);
2266 DBG(printf("JVM_CONSTANT_String: idx=#%03hd, %s", idx1, sym->as_utf8()));
2267 break;
2268 }
2269 case JVM_CONSTANT_Fieldref:
2270 case JVM_CONSTANT_Methodref:
2271 case JVM_CONSTANT_InterfaceMethodref: {
2272 idx1 = uncached_klass_ref_index_at(idx);
2273 idx2 = uncached_name_and_type_ref_index_at(idx);
2274 Bytes::put_Java_u2((address) (bytes+1), idx1);
2275 Bytes::put_Java_u2((address) (bytes+3), idx2);
2276 DBG(printf("JVM_CONSTANT_Methodref: %hd %hd", idx1, idx2));
2277 break;
2278 }
2279 case JVM_CONSTANT_NameAndType: {
2280 idx1 = name_ref_index_at(idx);
2281 idx2 = signature_ref_index_at(idx);
2282 Bytes::put_Java_u2((address) (bytes+1), idx1);
2283 Bytes::put_Java_u2((address) (bytes+3), idx2);
2284 DBG(printf("JVM_CONSTANT_NameAndType: %hd %hd", idx1, idx2));
2285 break;
2286 }
2287 case JVM_CONSTANT_ClassIndex: {
2288 *bytes = JVM_CONSTANT_Class;
2289 idx1 = checked_cast<u2>(klass_index_at(idx));
2290 Bytes::put_Java_u2((address) (bytes+1), idx1);
2291 DBG(printf("JVM_CONSTANT_ClassIndex: %hd", idx1));
2292 break;
2293 }
2294 case JVM_CONSTANT_StringIndex: {
2295 *bytes = JVM_CONSTANT_String;
2296 idx1 = checked_cast<u2>(string_index_at(idx));
2297 Bytes::put_Java_u2((address) (bytes+1), idx1);
2298 DBG(printf("JVM_CONSTANT_StringIndex: %hd", idx1));
2299 break;
2300 }
2301 case JVM_CONSTANT_MethodHandle:
2302 case JVM_CONSTANT_MethodHandleInError: {
2303 *bytes = JVM_CONSTANT_MethodHandle;
2304 int kind = method_handle_ref_kind_at(idx);
2305 idx1 = checked_cast<u2>(method_handle_index_at(idx));
2306 *(bytes+1) = (unsigned char) kind;
2307 Bytes::put_Java_u2((address) (bytes+2), idx1);
2308 DBG(printf("JVM_CONSTANT_MethodHandle: %d %hd", kind, idx1));
2309 break;
2310 }
2311 case JVM_CONSTANT_MethodType:
2312 case JVM_CONSTANT_MethodTypeInError: {
2313 *bytes = JVM_CONSTANT_MethodType;
2314 idx1 = checked_cast<u2>(method_type_index_at(idx));
2315 Bytes::put_Java_u2((address) (bytes+1), idx1);
2316 DBG(printf("JVM_CONSTANT_MethodType: %hd", idx1));
2317 break;
2318 }
2319 case JVM_CONSTANT_Dynamic:
2320 case JVM_CONSTANT_DynamicInError: {
2321 *bytes = tag;
2322 idx1 = extract_low_short_from_int(*int_at_addr(idx));
2323 idx2 = extract_high_short_from_int(*int_at_addr(idx));
2324 assert(idx2 == bootstrap_name_and_type_ref_index_at(idx), "correct half of u4");
2325 Bytes::put_Java_u2((address) (bytes+1), idx1);
2326 Bytes::put_Java_u2((address) (bytes+3), idx2);
2327 DBG(printf("JVM_CONSTANT_Dynamic: %hd %hd", idx1, idx2));
2328 break;
2329 }
2330 case JVM_CONSTANT_InvokeDynamic: {
2331 *bytes = tag;
2332 idx1 = extract_low_short_from_int(*int_at_addr(idx));
2333 idx2 = extract_high_short_from_int(*int_at_addr(idx));
2334 assert(idx2 == bootstrap_name_and_type_ref_index_at(idx), "correct half of u4");
2335 Bytes::put_Java_u2((address) (bytes+1), idx1);
2336 Bytes::put_Java_u2((address) (bytes+3), idx2);
2337 DBG(printf("JVM_CONSTANT_InvokeDynamic: %hd %hd", idx1, idx2));
2338 break;
2339 }
2340 }
2341 DBG(printf("\n"));
2342 bytes += ent_size;
2343 size += ent_size;
2344 }
2345 assert(size == cpool_size, "Size mismatch");
2346
2347 // Keep temporarily for debugging until it's stable.
2348 DBG(print_cpool_bytes(cnt, start_bytes));
2349 return (int)(bytes - start_bytes);
2350 } /* end copy_cpool_bytes */
2351
2352 #undef DBG
2353
2354 bool ConstantPool::is_maybe_on_stack() const {
2355 // This method uses the similar logic as nmethod::is_maybe_on_stack()
2356 if (!Continuations::enabled()) {
2357 return false;
2358 }
2359
2360 // If the condition below is true, it means that the nmethod was found to
2361 // be alive the previous completed marking cycle.
2362 return cache()->gc_epoch() >= CodeCache::previous_completed_gc_marking_cycle();
2363 }
2364
2365 // For redefinition, if any methods found in loom stack chunks, the gc_epoch is
2366 // recorded in their constant pool cache. The on_stack-ness of the constant pool controls whether
2367 // memory for the method is reclaimed.
2368 bool ConstantPool::on_stack() const {
2369 if ((_flags &_on_stack) != 0) {
2370 return true;
2371 }
2372
2373 if (_cache == nullptr) {
2374 return false;
2375 }
2376
2377 return is_maybe_on_stack();
2378 }
2379
2380 void ConstantPool::set_on_stack(const bool value) {
2381 if (value) {
2382 // Only record if it's not already set.
2383 if (!on_stack()) {
2384 assert(!is_shared(), "should always be set for shared constant pools");
2385 _flags |= _on_stack;
2386 MetadataOnStackMark::record(this);
2387 }
2388 } else {
2389 // Clearing is done single-threadedly.
2390 if (!is_shared()) {
2391 _flags &= (u2)(~_on_stack);
2392 }
2393 }
2394 }
2395
2396 // Printing
2397
2398 void ConstantPool::print_on(outputStream* st) const {
2399 assert(is_constantPool(), "must be constantPool");
2400 st->print_cr("%s", internal_name());
2401 if (flags() != 0) {
2402 st->print(" - flags: 0x%x", flags());
2403 if (has_preresolution()) st->print(" has_preresolution");
2404 if (on_stack()) st->print(" on_stack");
2405 st->cr();
2406 }
2407 if (pool_holder() != nullptr) {
2408 st->print_cr(" - holder: " PTR_FORMAT, p2i(pool_holder()));
2409 }
2410 st->print_cr(" - cache: " PTR_FORMAT, p2i(cache()));
2411 st->print_cr(" - resolved_references: " PTR_FORMAT, p2i(resolved_references_or_null()));
2412 st->print_cr(" - reference_map: " PTR_FORMAT, p2i(reference_map()));
2413 st->print_cr(" - resolved_klasses: " PTR_FORMAT, p2i(resolved_klasses()));
2414 st->print_cr(" - cp length: %d", length());
2415
2416 for (int index = 1; index < length(); index++) { // Index 0 is unused
2417 ((ConstantPool*)this)->print_entry_on(index, st);
2418 switch (tag_at(index).value()) {
2419 case JVM_CONSTANT_Long :
2420 case JVM_CONSTANT_Double :
2421 index++; // Skip entry following eigth-byte constant
2422 }
2423
2424 }
2425 st->cr();
2426 }
2427
2428 // Print one constant pool entry
2429 void ConstantPool::print_entry_on(const int cp_index, outputStream* st) {
2430 EXCEPTION_MARK;
2431 st->print(" - %3d : ", cp_index);
2432 tag_at(cp_index).print_on(st);
2433 st->print(" : ");
2434 switch (tag_at(cp_index).value()) {
2435 case JVM_CONSTANT_Class :
2436 { Klass* k = klass_at(cp_index, CATCH);
2437 guarantee(k != nullptr, "need klass");
2438 k->print_value_on(st);
2439 st->print(" {" PTR_FORMAT "}", p2i(k));
2440 }
2441 break;
2442 case JVM_CONSTANT_Fieldref :
2443 case JVM_CONSTANT_Methodref :
2444 case JVM_CONSTANT_InterfaceMethodref :
2445 st->print("klass_index=%d", uncached_klass_ref_index_at(cp_index));
2446 st->print(" name_and_type_index=%d", uncached_name_and_type_ref_index_at(cp_index));
2447 break;
2448 case JVM_CONSTANT_String :
2449 unresolved_string_at(cp_index)->print_value_on(st);
2450 break;
2451 case JVM_CONSTANT_Integer :
2452 st->print("%d", int_at(cp_index));
2453 break;
2454 case JVM_CONSTANT_Float :
2455 st->print("%f", float_at(cp_index));
2456 break;
2457 case JVM_CONSTANT_Long :
2458 st->print_jlong(long_at(cp_index));
2459 break;
2460 case JVM_CONSTANT_Double :
2461 st->print("%lf", double_at(cp_index));
2462 break;
2463 case JVM_CONSTANT_NameAndType :
2464 st->print("name_index=%d", name_ref_index_at(cp_index));
2465 st->print(" signature_index=%d", signature_ref_index_at(cp_index));
2466 break;
2467 case JVM_CONSTANT_Utf8 :
2468 symbol_at(cp_index)->print_value_on(st);
2469 break;
2470 case JVM_CONSTANT_ClassIndex: {
2471 int name_index = *int_at_addr(cp_index);
2472 st->print("klass_index=%d ", name_index);
2473 symbol_at(name_index)->print_value_on(st);
2474 }
2475 break;
2476 case JVM_CONSTANT_UnresolvedClass : // fall-through
2477 case JVM_CONSTANT_UnresolvedClassInError: {
2478 CPKlassSlot kslot = klass_slot_at(cp_index);
2479 int resolved_klass_index = kslot.resolved_klass_index();
2480 int name_index = kslot.name_index();
2481 assert(tag_at(name_index).is_symbol(), "sanity");
2482 symbol_at(name_index)->print_value_on(st);
2483 }
2484 break;
2485 case JVM_CONSTANT_MethodHandle :
2486 case JVM_CONSTANT_MethodHandleInError :
2487 st->print("ref_kind=%d", method_handle_ref_kind_at(cp_index));
2488 st->print(" ref_index=%d", method_handle_index_at(cp_index));
2489 break;
2490 case JVM_CONSTANT_MethodType :
2491 case JVM_CONSTANT_MethodTypeInError :
2492 st->print("signature_index=%d", method_type_index_at(cp_index));
2493 break;
2494 case JVM_CONSTANT_Dynamic :
2495 case JVM_CONSTANT_DynamicInError :
2496 {
2497 st->print("bootstrap_method_index=%d", bootstrap_method_ref_index_at(cp_index));
2498 st->print(" type_index=%d", bootstrap_name_and_type_ref_index_at(cp_index));
2499 int argc = bootstrap_argument_count_at(cp_index);
2500 if (argc > 0) {
2501 for (int arg_i = 0; arg_i < argc; arg_i++) {
2502 int arg = bootstrap_argument_index_at(cp_index, arg_i);
2503 st->print((arg_i == 0 ? " arguments={%d" : ", %d"), arg);
2504 }
2505 st->print("}");
2506 }
2507 }
2508 break;
2509 case JVM_CONSTANT_InvokeDynamic :
2510 {
2511 st->print("bootstrap_method_index=%d", bootstrap_method_ref_index_at(cp_index));
2512 st->print(" name_and_type_index=%d", bootstrap_name_and_type_ref_index_at(cp_index));
2513 int argc = bootstrap_argument_count_at(cp_index);
2514 if (argc > 0) {
2515 for (int arg_i = 0; arg_i < argc; arg_i++) {
2516 int arg = bootstrap_argument_index_at(cp_index, arg_i);
2517 st->print((arg_i == 0 ? " arguments={%d" : ", %d"), arg);
2518 }
2519 st->print("}");
2520 }
2521 }
2522 break;
2523 default:
2524 ShouldNotReachHere();
2525 break;
2526 }
2527 st->cr();
2528 }
2529
2530 void ConstantPool::print_value_on(outputStream* st) const {
2531 assert(is_constantPool(), "must be constantPool");
2532 st->print("constant pool [%d]", length());
2533 if (has_preresolution()) st->print("/preresolution");
2534 if (operands() != nullptr) st->print("/operands[%d]", operands()->length());
2535 print_address_on(st);
2536 if (pool_holder() != nullptr) {
2537 st->print(" for ");
2538 pool_holder()->print_value_on(st);
2539 bool extra = (pool_holder()->constants() != this);
2540 if (extra) st->print(" (extra)");
2541 }
2542 if (cache() != nullptr) {
2543 st->print(" cache=" PTR_FORMAT, p2i(cache()));
2544 }
2545 }
2546
2547 // Verification
2548
2549 void ConstantPool::verify_on(outputStream* st) {
2550 guarantee(is_constantPool(), "object must be constant pool");
2551 for (int i = 0; i< length(); i++) {
2552 constantTag tag = tag_at(i);
2553 if (tag.is_klass() || tag.is_unresolved_klass()) {
2554 guarantee(klass_name_at(i)->refcount() != 0, "should have nonzero reference count");
2555 } else if (tag.is_symbol()) {
2556 Symbol* entry = symbol_at(i);
2557 guarantee(entry->refcount() != 0, "should have nonzero reference count");
2558 } else if (tag.is_string()) {
2559 Symbol* entry = unresolved_string_at(i);
2560 guarantee(entry->refcount() != 0, "should have nonzero reference count");
2561 }
2562 }
2563 if (pool_holder() != nullptr) {
2564 // Note: pool_holder() can be null in temporary constant pools
2565 // used during constant pool merging
2566 guarantee(pool_holder()->is_klass(), "should be klass");
2567 }
2568 }