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