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