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