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