1 /*
2 * Copyright (c) 1997, 2016, 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 "classfile/classLoaderData.hpp"
27 #include "classfile/javaClasses.inline.hpp"
28 #include "classfile/metadataOnStackMark.hpp"
29 #include "classfile/stringTable.hpp"
30 #include "classfile/systemDictionary.hpp"
31 #include "classfile/vmSymbols.hpp"
32 #include "interpreter/linkResolver.hpp"
33 #include "memory/heapInspection.hpp"
34 #include "memory/metadataFactory.hpp"
35 #include "memory/oopFactory.hpp"
36 #include "oops/constantPool.hpp"
37 #include "oops/instanceKlass.hpp"
38 #include "oops/objArrayKlass.hpp"
39 #include "oops/objArrayOop.inline.hpp"
40 #include "oops/oop.inline.hpp"
41 #include "runtime/fieldType.hpp"
42 #include "runtime/init.hpp"
43 #include "runtime/javaCalls.hpp"
44 #include "runtime/signature.hpp"
45 #include "runtime/vframe.hpp"
46 #include "utilities/copy.hpp"
47
48 ConstantPool* ConstantPool::allocate(ClassLoaderData* loader_data, int length, TRAPS) {
49 // Tags are RW but comment below applies to tags also.
50 Array<u1>* tags = MetadataFactory::new_writeable_array<u1>(loader_data, length, 0, CHECK_NULL);
51
52 int size = ConstantPool::size(length);
53
54 // CDS considerations:
55 // Allocate read-write but may be able to move to read-only at dumping time
56 // if all the klasses are resolved. The only other field that is writable is
57 // the resolved_references array, which is recreated at startup time.
58 // But that could be moved to InstanceKlass (although a pain to access from
59 // assembly code). Maybe it could be moved to the cpCache which is RW.
60 return new (loader_data, size, false, MetaspaceObj::ConstantPoolType, THREAD) ConstantPool(tags);
61 }
62
63 #ifdef ASSERT
64
65 // MetaspaceObj allocation invariant is calloc equivalent memory
66 // simple verification of this here (JVM_CONSTANT_Invalid == 0 )
67 static bool tag_array_is_zero_initialized(Array<u1>* tags) {
68 assert(tags != NULL, "invariant");
69 const int length = tags->length();
70 for (int index = 0; index < length; ++index) {
71 if (JVM_CONSTANT_Invalid != tags->at(index)) {
72 return false;
73 }
74 }
75 return true;
76 }
77
78 #endif
79
80 ConstantPool::ConstantPool(Array<u1>* tags) :
81 _tags(tags),
82 _length(tags->length()) {
83
84 assert(_tags != NULL, "invariant");
85 assert(tags->length() == _length, "invariant");
86 assert(tag_array_is_zero_initialized(tags), "invariant");
87 assert(0 == _flags, "invariant");
88 assert(0 == version(), "invariant");
89 assert(NULL == _pool_holder, "invariant");
90 }
91
92 void ConstantPool::deallocate_contents(ClassLoaderData* loader_data) {
93 MetadataFactory::free_metadata(loader_data, cache());
94 set_cache(NULL);
95 MetadataFactory::free_array<u2>(loader_data, reference_map());
96 set_reference_map(NULL);
97
98 MetadataFactory::free_array<jushort>(loader_data, operands());
99 set_operands(NULL);
100
101 release_C_heap_structures();
102
103 // free tag array
104 MetadataFactory::free_array<u1>(loader_data, tags());
105 set_tags(NULL);
106 }
107
108 void ConstantPool::release_C_heap_structures() {
109 // walk constant pool and decrement symbol reference counts
110 unreference_symbols();
111 }
112
113 objArrayOop ConstantPool::resolved_references() const {
114 return (objArrayOop)JNIHandles::resolve(_resolved_references);
115 }
116
117 // Create resolved_references array and mapping array for original cp indexes
118 // The ldc bytecode was rewritten to have the resolved reference array index so need a way
119 // to map it back for resolving and some unlikely miscellaneous uses.
120 // The objects created by invokedynamic are appended to this list.
121 void ConstantPool::initialize_resolved_references(ClassLoaderData* loader_data,
122 const intStack& reference_map,
123 int constant_pool_map_length,
124 TRAPS) {
125 // Initialized the resolved object cache.
126 int map_length = reference_map.length();
127 if (map_length > 0) {
128 // Only need mapping back to constant pool entries. The map isn't used for
129 // invokedynamic resolved_reference entries. For invokedynamic entries,
130 // the constant pool cache index has the mapping back to both the constant
131 // pool and to the resolved reference index.
132 if (constant_pool_map_length > 0) {
133 Array<u2>* om = MetadataFactory::new_array<u2>(loader_data, constant_pool_map_length, CHECK);
134
135 for (int i = 0; i < constant_pool_map_length; i++) {
136 int x = reference_map.at(i);
137 assert(x == (int)(jushort) x, "klass index is too big");
138 om->at_put(i, (jushort)x);
139 }
140 set_reference_map(om);
141 }
142
143 // Create Java array for holding resolved strings, methodHandles,
144 // methodTypes, invokedynamic and invokehandle appendix objects, etc.
145 objArrayOop stom = oopFactory::new_objArray(SystemDictionary::Object_klass(), map_length, CHECK);
146 Handle refs_handle (THREAD, (oop)stom); // must handleize.
147 set_resolved_references(loader_data->add_handle(refs_handle));
148 }
149 }
150
151 // CDS support. Create a new resolved_references array.
152 void ConstantPool::restore_unshareable_info(TRAPS) {
153
154 // Only create the new resolved references array if it hasn't been attempted before
155 if (resolved_references() != NULL) return;
156
157 // restore the C++ vtable from the shared archive
158 restore_vtable();
159
160 if (SystemDictionary::Object_klass_loaded()) {
161 // Recreate the object array and add to ClassLoaderData.
162 int map_length = resolved_reference_length();
163 if (map_length > 0) {
164 objArrayOop stom = oopFactory::new_objArray(SystemDictionary::Object_klass(), map_length, CHECK);
165 Handle refs_handle (THREAD, (oop)stom); // must handleize.
166
167 ClassLoaderData* loader_data = pool_holder()->class_loader_data();
168 set_resolved_references(loader_data->add_handle(refs_handle));
169 }
170 }
171 }
172
173 void ConstantPool::remove_unshareable_info() {
174 // Resolved references are not in the shared archive.
175 // Save the length for restoration. It is not necessarily the same length
176 // as reference_map.length() if invokedynamic is saved.
177 set_resolved_reference_length(
178 resolved_references() != NULL ? resolved_references()->length() : 0);
179 set_resolved_references(NULL);
180 }
181
182 int ConstantPool::cp_to_object_index(int cp_index) {
183 // this is harder don't do this so much.
184 int i = reference_map()->find(cp_index);
185 // We might not find the index for jsr292 call.
186 return (i < 0) ? _no_index_sentinel : i;
187 }
188
189 void ConstantPool::string_at_put(int which, int obj_index, oop str) {
190 resolved_references()->obj_at_put(obj_index, str);
191 }
192
193 void ConstantPool::trace_class_resolution(const constantPoolHandle& this_cp, KlassHandle k) {
194 ResourceMark rm;
195 int line_number = -1;
196 const char * source_file = NULL;
197 if (JavaThread::current()->has_last_Java_frame()) {
198 // try to identify the method which called this function.
199 vframeStream vfst(JavaThread::current());
200 if (!vfst.at_end()) {
201 line_number = vfst.method()->line_number_from_bci(vfst.bci());
202 Symbol* s = vfst.method()->method_holder()->source_file_name();
203 if (s != NULL) {
204 source_file = s->as_C_string();
205 }
206 }
207 }
208 if (k() != this_cp->pool_holder()) {
209 // only print something if the classes are different
210 if (source_file != NULL) {
211 log_info(classresolve)("%s %s %s:%d",
212 this_cp->pool_holder()->external_name(),
213 k->external_name(), source_file, line_number);
214 } else {
215 log_info(classresolve)("%s %s",
216 this_cp->pool_holder()->external_name(),
217 k->external_name());
218 }
219 }
220 }
221
222 Klass* ConstantPool::klass_at_impl(const constantPoolHandle& this_cp, int which,
223 bool save_resolution_error, TRAPS) {
224 assert(THREAD->is_Java_thread(), "must be a Java thread");
225
226 // A resolved constantPool entry will contain a Klass*, otherwise a Symbol*.
227 // It is not safe to rely on the tag bit's here, since we don't have a lock, and
228 // the entry and tag is not updated atomicly.
229 CPSlot entry = this_cp->slot_at(which);
230 if (entry.is_resolved()) {
231 assert(entry.get_klass()->is_klass(), "must be");
232 // Already resolved - return entry.
233 return entry.get_klass();
234 }
235
236 // This tag doesn't change back to unresolved class unless at a safepoint.
237 if (this_cp->tag_at(which).is_unresolved_klass_in_error()) {
238 // The original attempt to resolve this constant pool entry failed so find the
239 // class of the original error and throw another error of the same class
240 // (JVMS 5.4.3).
241 // If there is a detail message, pass that detail message to the error.
242 // The JVMS does not strictly require us to duplicate the same detail message,
243 // or any internal exception fields such as cause or stacktrace. But since the
244 // detail message is often a class name or other literal string, we will repeat it
245 // if we can find it in the symbol table.
246 throw_resolution_error(this_cp, which, CHECK_0);
247 ShouldNotReachHere();
248 }
249
250 Handle mirror_handle;
251 Symbol* name = entry.get_symbol();
252 Handle loader (THREAD, this_cp->pool_holder()->class_loader());
253 Handle protection_domain (THREAD, this_cp->pool_holder()->protection_domain());
254 Klass* kk = SystemDictionary::resolve_or_fail(name, loader, protection_domain, true, THREAD);
255 KlassHandle k (THREAD, kk);
256 if (!HAS_PENDING_EXCEPTION) {
257 // preserve the resolved klass from unloading
258 mirror_handle = Handle(THREAD, kk->java_mirror());
259 // Do access check for klasses
260 verify_constant_pool_resolve(this_cp, k, THREAD);
261 }
262
263 // Failed to resolve class. We must record the errors so that subsequent attempts
264 // to resolve this constant pool entry fail with the same error (JVMS 5.4.3).
265 if (HAS_PENDING_EXCEPTION) {
266 if (save_resolution_error) {
267 save_and_throw_exception(this_cp, which, constantTag(JVM_CONSTANT_UnresolvedClass), CHECK_NULL);
268 // If CHECK_NULL above doesn't return the exception, that means that
269 // some other thread has beaten us and has resolved the class.
270 // To preserve old behavior, we return the resolved class.
271 entry = this_cp->resolved_klass_at(which);
272 assert(entry.is_resolved(), "must be resolved if exception was cleared");
273 assert(entry.get_klass()->is_klass(), "must be resolved to a klass");
274 return entry.get_klass();
275 } else {
276 return NULL; // return the pending exception
277 }
278 }
279
280 // Make this class loader depend upon the class loader owning the class reference
281 ClassLoaderData* this_key = this_cp->pool_holder()->class_loader_data();
282 this_key->record_dependency(k(), CHECK_NULL); // Can throw OOM
283
284 if (log_is_enabled(Info, classresolve) && !k->is_array_klass()) {
285 // skip resolving the constant pool so that this code gets
286 // called the next time some bytecodes refer to this class.
287 trace_class_resolution(this_cp, k);
288 return k();
289 } else {
290 this_cp->klass_at_put(which, k());
291 }
292
293 entry = this_cp->resolved_klass_at(which);
294 assert(entry.is_resolved() && entry.get_klass()->is_klass(), "must be resolved at this point");
295 return entry.get_klass();
296 }
297
298
299 // Does not update ConstantPool* - to avoid any exception throwing. Used
300 // by compiler and exception handling. Also used to avoid classloads for
301 // instanceof operations. Returns NULL if the class has not been loaded or
302 // if the verification of constant pool failed
303 Klass* ConstantPool::klass_at_if_loaded(const constantPoolHandle& this_cp, int which) {
304 CPSlot entry = this_cp->slot_at(which);
305 if (entry.is_resolved()) {
306 assert(entry.get_klass()->is_klass(), "must be");
307 return entry.get_klass();
308 } else {
309 assert(entry.is_unresolved(), "must be either symbol or klass");
310 Thread *thread = Thread::current();
311 Symbol* name = entry.get_symbol();
312 oop loader = this_cp->pool_holder()->class_loader();
313 oop protection_domain = this_cp->pool_holder()->protection_domain();
314 Handle h_prot (thread, protection_domain);
315 Handle h_loader (thread, loader);
316 Klass* k = SystemDictionary::find(name, h_loader, h_prot, thread);
317
318 if (k != NULL) {
319 // Make sure that resolving is legal
320 EXCEPTION_MARK;
321 KlassHandle klass(THREAD, k);
322 // return NULL if verification fails
323 verify_constant_pool_resolve(this_cp, klass, THREAD);
324 if (HAS_PENDING_EXCEPTION) {
325 CLEAR_PENDING_EXCEPTION;
326 return NULL;
327 }
328 return klass();
329 } else {
330 return k;
331 }
332 }
333 }
334
335
336 Klass* ConstantPool::klass_ref_at_if_loaded(const constantPoolHandle& this_cp, int which) {
337 return klass_at_if_loaded(this_cp, this_cp->klass_ref_index_at(which));
338 }
339
340
341 Method* ConstantPool::method_at_if_loaded(const constantPoolHandle& cpool,
342 int which) {
343 if (cpool->cache() == NULL) return NULL; // nothing to load yet
344 int cache_index = decode_cpcache_index(which, true);
345 if (!(cache_index >= 0 && cache_index < cpool->cache()->length())) {
346 // FIXME: should be an assert
347 if (PrintMiscellaneous && (Verbose||WizardMode)) {
348 tty->print_cr("bad operand %d in:", which); cpool->print();
349 }
350 return NULL;
351 }
352 ConstantPoolCacheEntry* e = cpool->cache()->entry_at(cache_index);
353 return e->method_if_resolved(cpool);
354 }
355
356
357 bool ConstantPool::has_appendix_at_if_loaded(const constantPoolHandle& cpool, int which) {
358 if (cpool->cache() == NULL) return false; // nothing to load yet
359 int cache_index = decode_cpcache_index(which, true);
360 ConstantPoolCacheEntry* e = cpool->cache()->entry_at(cache_index);
361 return e->has_appendix();
362 }
363
364 oop ConstantPool::appendix_at_if_loaded(const constantPoolHandle& cpool, int which) {
365 if (cpool->cache() == NULL) return NULL; // nothing to load yet
366 int cache_index = decode_cpcache_index(which, true);
367 ConstantPoolCacheEntry* e = cpool->cache()->entry_at(cache_index);
368 return e->appendix_if_resolved(cpool);
369 }
370
371
372 bool ConstantPool::has_method_type_at_if_loaded(const constantPoolHandle& cpool, int which) {
373 if (cpool->cache() == NULL) return false; // nothing to load yet
374 int cache_index = decode_cpcache_index(which, true);
375 ConstantPoolCacheEntry* e = cpool->cache()->entry_at(cache_index);
376 return e->has_method_type();
377 }
378
379 oop ConstantPool::method_type_at_if_loaded(const constantPoolHandle& cpool, int which) {
380 if (cpool->cache() == NULL) return NULL; // nothing to load yet
381 int cache_index = decode_cpcache_index(which, true);
382 ConstantPoolCacheEntry* e = cpool->cache()->entry_at(cache_index);
383 return e->method_type_if_resolved(cpool);
384 }
385
386
387 Symbol* ConstantPool::impl_name_ref_at(int which, bool uncached) {
388 int name_index = name_ref_index_at(impl_name_and_type_ref_index_at(which, uncached));
389 return symbol_at(name_index);
390 }
391
392
393 Symbol* ConstantPool::impl_signature_ref_at(int which, bool uncached) {
394 int signature_index = signature_ref_index_at(impl_name_and_type_ref_index_at(which, uncached));
395 return symbol_at(signature_index);
396 }
397
398
399 int ConstantPool::impl_name_and_type_ref_index_at(int which, bool uncached) {
400 int i = which;
401 if (!uncached && cache() != NULL) {
402 if (ConstantPool::is_invokedynamic_index(which)) {
403 // Invokedynamic index is index into resolved_references
404 int pool_index = invokedynamic_cp_cache_entry_at(which)->constant_pool_index();
405 pool_index = invoke_dynamic_name_and_type_ref_index_at(pool_index);
406 assert(tag_at(pool_index).is_name_and_type(), "");
407 return pool_index;
408 }
409 // change byte-ordering and go via cache
410 i = remap_instruction_operand_from_cache(which);
411 } else {
412 if (tag_at(which).is_invoke_dynamic()) {
413 int pool_index = invoke_dynamic_name_and_type_ref_index_at(which);
414 assert(tag_at(pool_index).is_name_and_type(), "");
415 return pool_index;
416 }
417 }
418 assert(tag_at(i).is_field_or_method(), "Corrupted constant pool");
419 assert(!tag_at(i).is_invoke_dynamic(), "Must be handled above");
420 jint ref_index = *int_at_addr(i);
421 return extract_high_short_from_int(ref_index);
422 }
423
424
425 int ConstantPool::impl_klass_ref_index_at(int which, bool uncached) {
426 guarantee(!ConstantPool::is_invokedynamic_index(which),
427 "an invokedynamic instruction does not have a klass");
428 int i = which;
429 if (!uncached && cache() != NULL) {
430 // change byte-ordering and go via cache
431 i = remap_instruction_operand_from_cache(which);
432 }
433 assert(tag_at(i).is_field_or_method(), "Corrupted constant pool");
434 jint ref_index = *int_at_addr(i);
435 return extract_low_short_from_int(ref_index);
436 }
437
438
439
440 int ConstantPool::remap_instruction_operand_from_cache(int operand) {
441 int cpc_index = operand;
442 DEBUG_ONLY(cpc_index -= CPCACHE_INDEX_TAG);
443 assert((int)(u2)cpc_index == cpc_index, "clean u2");
444 int member_index = cache()->entry_at(cpc_index)->constant_pool_index();
445 return member_index;
446 }
447
448
449 void ConstantPool::verify_constant_pool_resolve(const constantPoolHandle& this_cp, KlassHandle k, TRAPS) {
450 if (k->is_instance_klass() || k->is_objArray_klass()) {
451 instanceKlassHandle holder (THREAD, this_cp->pool_holder());
452 Klass* elem = k->is_instance_klass() ? k() : ObjArrayKlass::cast(k())->bottom_klass();
453 KlassHandle element (THREAD, elem);
454
455 // The element type could be a typeArray - we only need the access check if it is
456 // an reference to another class
457 if (element->is_instance_klass()) {
458 LinkResolver::check_klass_accessability(holder, element, CHECK);
459 }
460 }
461 }
462
463
464 int ConstantPool::name_ref_index_at(int which_nt) {
465 jint ref_index = name_and_type_at(which_nt);
466 return extract_low_short_from_int(ref_index);
467 }
468
469
470 int ConstantPool::signature_ref_index_at(int which_nt) {
471 jint ref_index = name_and_type_at(which_nt);
472 return extract_high_short_from_int(ref_index);
473 }
474
475
476 Klass* ConstantPool::klass_ref_at(int which, TRAPS) {
477 return klass_at(klass_ref_index_at(which), THREAD);
478 }
479
480
481 Symbol* ConstantPool::klass_name_at(int which) const {
482 assert(tag_at(which).is_unresolved_klass() || tag_at(which).is_klass(),
483 "Corrupted constant pool");
484 // A resolved constantPool entry will contain a Klass*, otherwise a Symbol*.
485 // It is not safe to rely on the tag bit's here, since we don't have a lock, and the entry and
486 // tag is not updated atomicly.
487 CPSlot entry = slot_at(which);
488 if (entry.is_resolved()) {
489 // Already resolved - return entry's name.
490 assert(entry.get_klass()->is_klass(), "must be");
491 return entry.get_klass()->name();
492 } else {
493 assert(entry.is_unresolved(), "must be either symbol or klass");
494 return entry.get_symbol();
495 }
496 }
497
498 Symbol* ConstantPool::klass_ref_at_noresolve(int which) {
499 jint ref_index = klass_ref_index_at(which);
500 return klass_at_noresolve(ref_index);
501 }
502
503 Symbol* ConstantPool::uncached_klass_ref_at_noresolve(int which) {
504 jint ref_index = uncached_klass_ref_index_at(which);
505 return klass_at_noresolve(ref_index);
506 }
507
508 char* ConstantPool::string_at_noresolve(int which) {
509 return unresolved_string_at(which)->as_C_string();
510 }
511
512 BasicType ConstantPool::basic_type_for_signature_at(int which) const {
513 return FieldType::basic_type(symbol_at(which));
514 }
515
516
517 void ConstantPool::resolve_string_constants_impl(const constantPoolHandle& this_cp, TRAPS) {
518 for (int index = 1; index < this_cp->length(); index++) { // Index 0 is unused
519 if (this_cp->tag_at(index).is_string()) {
520 this_cp->string_at(index, CHECK);
521 }
522 }
523 }
524
525 // Resolve all the classes in the constant pool. If they are all resolved,
526 // the constant pool is read-only. Enhancement: allocate cp entries to
527 // another metaspace, and copy to read-only or read-write space if this
528 // bit is set.
529 bool ConstantPool::resolve_class_constants(TRAPS) {
530 constantPoolHandle cp(THREAD, this);
531 for (int index = 1; index < length(); index++) { // Index 0 is unused
532 if (tag_at(index).is_unresolved_klass() &&
533 klass_at_if_loaded(cp, index) == NULL) {
534 return false;
535 }
536 }
537 // set_preresolution(); or some bit for future use
538 return true;
539 }
540
541 Symbol* ConstantPool::exception_message(const constantPoolHandle& this_cp, int which, constantTag tag, oop pending_exception) {
542 // Dig out the detailed message to reuse if possible
543 Symbol* message = java_lang_Throwable::detail_message(pending_exception);
544 if (message != NULL) {
545 return message;
546 }
547
548 // Return specific message for the tag
549 switch (tag.value()) {
550 case JVM_CONSTANT_UnresolvedClass:
551 // return the class name in the error message
552 message = this_cp->klass_name_at(which);
553 break;
554 case JVM_CONSTANT_MethodHandle:
555 // return the method handle name in the error message
556 message = this_cp->method_handle_name_ref_at(which);
557 break;
558 case JVM_CONSTANT_MethodType:
559 // return the method type signature in the error message
560 message = this_cp->method_type_signature_at(which);
561 break;
562 default:
563 ShouldNotReachHere();
564 }
565
566 return message;
567 }
568
569 void ConstantPool::throw_resolution_error(const constantPoolHandle& this_cp, int which, TRAPS) {
570 Symbol* message = NULL;
571 Symbol* error = SystemDictionary::find_resolution_error(this_cp, which, &message);
572 assert(error != NULL && message != NULL, "checking");
573 CLEAR_PENDING_EXCEPTION;
574 ResourceMark rm;
575 THROW_MSG(error, message->as_C_string());
576 }
577
578 // If resolution for Class, MethodHandle or MethodType fails, save the exception
579 // in the resolution error table, so that the same exception is thrown again.
580 void ConstantPool::save_and_throw_exception(const constantPoolHandle& this_cp, int which,
581 constantTag tag, TRAPS) {
582 Symbol* error = PENDING_EXCEPTION->klass()->name();
583
584 int error_tag = tag.error_value();
585
586 if (!PENDING_EXCEPTION->
587 is_a(SystemDictionary::LinkageError_klass())) {
588 // Just throw the exception and don't prevent these classes from
589 // being loaded due to virtual machine errors like StackOverflow
590 // and OutOfMemoryError, etc, or if the thread was hit by stop()
591 // Needs clarification to section 5.4.3 of the VM spec (see 6308271)
592 } else if (this_cp->tag_at(which).value() != error_tag) {
593 Symbol* message = exception_message(this_cp, which, tag, PENDING_EXCEPTION);
594 SystemDictionary::add_resolution_error(this_cp, which, error, message);
595 // CAS in the tag. If a thread beat us to registering this error that's fine.
596 // If another thread resolved the reference, this is a race condition. This
597 // thread may have had a security manager or something temporary.
598 // This doesn't deterministically get an error. So why do we save this?
599 // We save this because jvmti can add classes to the bootclass path after
600 // this error, so it needs to get the same error if the error is first.
601 jbyte old_tag = Atomic::cmpxchg((jbyte)error_tag,
602 (jbyte*)this_cp->tag_addr_at(which), (jbyte)tag.value());
603 if (old_tag != error_tag && old_tag != tag.value()) {
604 // MethodHandles and MethodType doesn't change to resolved version.
605 assert(this_cp->tag_at(which).is_klass(), "Wrong tag value");
606 // Forget the exception and use the resolved class.
607 CLEAR_PENDING_EXCEPTION;
608 }
609 } else {
610 // some other thread put this in error state
611 throw_resolution_error(this_cp, which, CHECK);
612 }
613 }
614
615 // Called to resolve constants in the constant pool and return an oop.
616 // Some constant pool entries cache their resolved oop. This is also
617 // called to create oops from constants to use in arguments for invokedynamic
618 oop ConstantPool::resolve_constant_at_impl(const constantPoolHandle& this_cp, int index, int cache_index, TRAPS) {
619 oop result_oop = NULL;
620 Handle throw_exception;
621
622 if (cache_index == _possible_index_sentinel) {
623 // It is possible that this constant is one which is cached in the objects.
624 // We'll do a linear search. This should be OK because this usage is rare.
625 assert(index > 0, "valid index");
626 cache_index = this_cp->cp_to_object_index(index);
627 }
628 assert(cache_index == _no_index_sentinel || cache_index >= 0, "");
629 assert(index == _no_index_sentinel || index >= 0, "");
630
631 if (cache_index >= 0) {
632 result_oop = this_cp->resolved_references()->obj_at(cache_index);
633 if (result_oop != NULL) {
634 return result_oop;
635 // That was easy...
636 }
637 index = this_cp->object_to_cp_index(cache_index);
638 }
639
640 jvalue prim_value; // temp used only in a few cases below
641
642 constantTag tag = this_cp->tag_at(index);
643
644 switch (tag.value()) {
645
646 case JVM_CONSTANT_UnresolvedClass:
647 case JVM_CONSTANT_UnresolvedClassInError:
648 case JVM_CONSTANT_Class:
649 {
650 assert(cache_index == _no_index_sentinel, "should not have been set");
651 Klass* resolved = klass_at_impl(this_cp, index, true, CHECK_NULL);
652 // ldc wants the java mirror.
653 result_oop = resolved->java_mirror();
654 break;
655 }
656
657 case JVM_CONSTANT_String:
658 assert(cache_index != _no_index_sentinel, "should have been set");
659 if (this_cp->is_pseudo_string_at(index)) {
660 result_oop = this_cp->pseudo_string_at(index, cache_index);
661 break;
662 }
663 result_oop = string_at_impl(this_cp, index, cache_index, CHECK_NULL);
664 break;
665
666 case JVM_CONSTANT_MethodHandleInError:
667 case JVM_CONSTANT_MethodTypeInError:
668 {
669 throw_resolution_error(this_cp, index, CHECK_NULL);
670 break;
671 }
672
673 case JVM_CONSTANT_MethodHandle:
674 {
675 int ref_kind = this_cp->method_handle_ref_kind_at(index);
676 int callee_index = this_cp->method_handle_klass_index_at(index);
677 Symbol* name = this_cp->method_handle_name_ref_at(index);
678 Symbol* signature = this_cp->method_handle_signature_ref_at(index);
679 if (PrintMiscellaneous)
680 tty->print_cr("resolve JVM_CONSTANT_MethodHandle:%d [%d/%d/%d] %s.%s",
681 ref_kind, index, this_cp->method_handle_index_at(index),
682 callee_index, name->as_C_string(), signature->as_C_string());
683 KlassHandle callee;
684 { Klass* k = klass_at_impl(this_cp, callee_index, true, CHECK_NULL);
685 callee = KlassHandle(THREAD, k);
686 }
687 KlassHandle klass(THREAD, this_cp->pool_holder());
688 Handle value = SystemDictionary::link_method_handle_constant(klass, ref_kind,
689 callee, name, signature,
690 THREAD);
691 result_oop = value();
692 if (HAS_PENDING_EXCEPTION) {
693 save_and_throw_exception(this_cp, index, tag, CHECK_NULL);
694 }
695 break;
696 }
697
698 case JVM_CONSTANT_MethodType:
699 {
700 Symbol* signature = this_cp->method_type_signature_at(index);
701 if (PrintMiscellaneous)
702 tty->print_cr("resolve JVM_CONSTANT_MethodType [%d/%d] %s",
703 index, this_cp->method_type_index_at(index),
704 signature->as_C_string());
705 KlassHandle klass(THREAD, this_cp->pool_holder());
706 Handle value = SystemDictionary::find_method_handle_type(signature, klass, THREAD);
707 result_oop = value();
708 if (HAS_PENDING_EXCEPTION) {
709 save_and_throw_exception(this_cp, index, tag, CHECK_NULL);
710 }
711 break;
712 }
713
714 case JVM_CONSTANT_Integer:
715 assert(cache_index == _no_index_sentinel, "should not have been set");
716 prim_value.i = this_cp->int_at(index);
717 result_oop = java_lang_boxing_object::create(T_INT, &prim_value, CHECK_NULL);
718 break;
719
720 case JVM_CONSTANT_Float:
721 assert(cache_index == _no_index_sentinel, "should not have been set");
722 prim_value.f = this_cp->float_at(index);
723 result_oop = java_lang_boxing_object::create(T_FLOAT, &prim_value, CHECK_NULL);
724 break;
725
726 case JVM_CONSTANT_Long:
727 assert(cache_index == _no_index_sentinel, "should not have been set");
728 prim_value.j = this_cp->long_at(index);
729 result_oop = java_lang_boxing_object::create(T_LONG, &prim_value, CHECK_NULL);
730 break;
731
732 case JVM_CONSTANT_Double:
733 assert(cache_index == _no_index_sentinel, "should not have been set");
734 prim_value.d = this_cp->double_at(index);
735 result_oop = java_lang_boxing_object::create(T_DOUBLE, &prim_value, CHECK_NULL);
736 break;
737
738 default:
739 DEBUG_ONLY( tty->print_cr("*** %p: tag at CP[%d/%d] = %d",
740 this_cp(), index, cache_index, tag.value()));
741 assert(false, "unexpected constant tag");
742 break;
743 }
744
745 if (cache_index >= 0) {
746 // Benign race condition: resolved_references may already be filled in.
747 // The important thing here is that all threads pick up the same result.
748 // It doesn't matter which racing thread wins, as long as only one
749 // result is used by all threads, and all future queries.
750 oop old_result = this_cp->resolved_references()->atomic_compare_exchange_oop(cache_index, result_oop, NULL);
751 if (old_result == NULL) {
752 return result_oop; // was installed
753 } else {
754 // Return the winning thread's result. This can be different than
755 // the result here for MethodHandles.
756 return old_result;
757 }
758 } else {
759 return result_oop;
760 }
761 }
762
763 oop ConstantPool::uncached_string_at(int which, TRAPS) {
764 Symbol* sym = unresolved_string_at(which);
765 oop str = StringTable::intern(sym, CHECK_(NULL));
766 assert(java_lang_String::is_instance(str), "must be string");
767 return str;
768 }
769
770
771 oop ConstantPool::resolve_bootstrap_specifier_at_impl(const constantPoolHandle& this_cp, int index, TRAPS) {
772 assert(this_cp->tag_at(index).is_invoke_dynamic(), "Corrupted constant pool");
773
774 Handle bsm;
775 int argc;
776 {
777 // JVM_CONSTANT_InvokeDynamic is an ordered pair of [bootm, name&type], plus optional arguments
778 // The bootm, being a JVM_CONSTANT_MethodHandle, has its own cache entry.
779 // It is accompanied by the optional arguments.
780 int bsm_index = this_cp->invoke_dynamic_bootstrap_method_ref_index_at(index);
781 oop bsm_oop = this_cp->resolve_possibly_cached_constant_at(bsm_index, CHECK_NULL);
782 if (!java_lang_invoke_MethodHandle::is_instance(bsm_oop)) {
783 THROW_MSG_NULL(vmSymbols::java_lang_LinkageError(), "BSM not an MethodHandle");
784 }
785
786 // Extract the optional static arguments.
787 argc = this_cp->invoke_dynamic_argument_count_at(index);
788 if (argc == 0) return bsm_oop;
789
790 bsm = Handle(THREAD, bsm_oop);
791 }
792
793 objArrayHandle info;
794 {
795 objArrayOop info_oop = oopFactory::new_objArray(SystemDictionary::Object_klass(), 1+argc, CHECK_NULL);
796 info = objArrayHandle(THREAD, info_oop);
797 }
798
799 info->obj_at_put(0, bsm());
800 for (int i = 0; i < argc; i++) {
801 int arg_index = this_cp->invoke_dynamic_argument_index_at(index, i);
802 oop arg_oop = this_cp->resolve_possibly_cached_constant_at(arg_index, CHECK_NULL);
803 info->obj_at_put(1+i, arg_oop);
804 }
805
806 return info();
807 }
808
809 oop ConstantPool::string_at_impl(const constantPoolHandle& this_cp, int which, int obj_index, TRAPS) {
810 // If the string has already been interned, this entry will be non-null
811 oop str = this_cp->resolved_references()->obj_at(obj_index);
812 if (str != NULL) return str;
813 Symbol* sym = this_cp->unresolved_string_at(which);
814 str = StringTable::intern(sym, CHECK_(NULL));
815 this_cp->string_at_put(which, obj_index, str);
816 assert(java_lang_String::is_instance(str), "must be string");
817 return str;
818 }
819
820
821 bool ConstantPool::klass_name_at_matches(instanceKlassHandle k,
822 int which) {
823 // Names are interned, so we can compare Symbol*s directly
824 Symbol* cp_name = klass_name_at(which);
825 return (cp_name == k->name());
826 }
827
828
829 // Iterate over symbols and decrement ones which are Symbol*s
830 // This is done during GC.
831 // Only decrement the UTF8 symbols. Unresolved classes and strings point to
832 // these symbols but didn't increment the reference count.
833 void ConstantPool::unreference_symbols() {
834 for (int index = 1; index < length(); index++) { // Index 0 is unused
835 constantTag tag = tag_at(index);
836 if (tag.is_symbol()) {
837 symbol_at(index)->decrement_refcount();
838 }
839 }
840 }
841
842
843 // Compare this constant pool's entry at index1 to the constant pool
844 // cp2's entry at index2.
845 bool ConstantPool::compare_entry_to(int index1, const constantPoolHandle& cp2,
846 int index2, TRAPS) {
847
848 // The error tags are equivalent to non-error tags when comparing
849 jbyte t1 = tag_at(index1).non_error_value();
850 jbyte t2 = cp2->tag_at(index2).non_error_value();
851
852 if (t1 != t2) {
853 // Not the same entry type so there is nothing else to check. Note
854 // that this style of checking will consider resolved/unresolved
855 // class pairs as different.
856 // From the ConstantPool* API point of view, this is correct
857 // behavior. See VM_RedefineClasses::merge_constant_pools() to see how this
858 // plays out in the context of ConstantPool* merging.
859 return false;
860 }
861
862 switch (t1) {
863 case JVM_CONSTANT_Class:
864 {
865 Klass* k1 = klass_at(index1, CHECK_false);
866 Klass* k2 = cp2->klass_at(index2, CHECK_false);
867 if (k1 == k2) {
868 return true;
869 }
870 } break;
871
872 case JVM_CONSTANT_ClassIndex:
873 {
874 int recur1 = klass_index_at(index1);
875 int recur2 = cp2->klass_index_at(index2);
876 bool match = compare_entry_to(recur1, cp2, recur2, CHECK_false);
877 if (match) {
878 return true;
879 }
880 } break;
881
882 case JVM_CONSTANT_Double:
883 {
884 jdouble d1 = double_at(index1);
885 jdouble d2 = cp2->double_at(index2);
886 if (d1 == d2) {
887 return true;
888 }
889 } break;
890
891 case JVM_CONSTANT_Fieldref:
892 case JVM_CONSTANT_InterfaceMethodref:
893 case JVM_CONSTANT_Methodref:
894 {
895 int recur1 = uncached_klass_ref_index_at(index1);
896 int recur2 = cp2->uncached_klass_ref_index_at(index2);
897 bool match = compare_entry_to(recur1, cp2, recur2, CHECK_false);
898 if (match) {
899 recur1 = uncached_name_and_type_ref_index_at(index1);
900 recur2 = cp2->uncached_name_and_type_ref_index_at(index2);
901 match = compare_entry_to(recur1, cp2, recur2, CHECK_false);
902 if (match) {
903 return true;
904 }
905 }
906 } break;
907
908 case JVM_CONSTANT_Float:
909 {
910 jfloat f1 = float_at(index1);
911 jfloat f2 = cp2->float_at(index2);
912 if (f1 == f2) {
913 return true;
914 }
915 } break;
916
917 case JVM_CONSTANT_Integer:
918 {
919 jint i1 = int_at(index1);
920 jint i2 = cp2->int_at(index2);
921 if (i1 == i2) {
922 return true;
923 }
924 } break;
925
926 case JVM_CONSTANT_Long:
927 {
928 jlong l1 = long_at(index1);
929 jlong l2 = cp2->long_at(index2);
930 if (l1 == l2) {
931 return true;
932 }
933 } break;
934
935 case JVM_CONSTANT_NameAndType:
936 {
937 int recur1 = name_ref_index_at(index1);
938 int recur2 = cp2->name_ref_index_at(index2);
939 bool match = compare_entry_to(recur1, cp2, recur2, CHECK_false);
940 if (match) {
941 recur1 = signature_ref_index_at(index1);
942 recur2 = cp2->signature_ref_index_at(index2);
943 match = compare_entry_to(recur1, cp2, recur2, CHECK_false);
944 if (match) {
945 return true;
946 }
947 }
948 } break;
949
950 case JVM_CONSTANT_StringIndex:
951 {
952 int recur1 = string_index_at(index1);
953 int recur2 = cp2->string_index_at(index2);
954 bool match = compare_entry_to(recur1, cp2, recur2, CHECK_false);
955 if (match) {
956 return true;
957 }
958 } break;
959
960 case JVM_CONSTANT_UnresolvedClass:
961 {
962 Symbol* k1 = klass_name_at(index1);
963 Symbol* k2 = cp2->klass_name_at(index2);
964 if (k1 == k2) {
965 return true;
966 }
967 } break;
968
969 case JVM_CONSTANT_MethodType:
970 {
971 int k1 = method_type_index_at_error_ok(index1);
972 int k2 = cp2->method_type_index_at_error_ok(index2);
973 bool match = compare_entry_to(k1, cp2, k2, CHECK_false);
974 if (match) {
975 return true;
976 }
977 } break;
978
979 case JVM_CONSTANT_MethodHandle:
980 {
981 int k1 = method_handle_ref_kind_at_error_ok(index1);
982 int k2 = cp2->method_handle_ref_kind_at_error_ok(index2);
983 if (k1 == k2) {
984 int i1 = method_handle_index_at_error_ok(index1);
985 int i2 = cp2->method_handle_index_at_error_ok(index2);
986 bool match = compare_entry_to(i1, cp2, i2, CHECK_false);
987 if (match) {
988 return true;
989 }
990 }
991 } break;
992
993 case JVM_CONSTANT_InvokeDynamic:
994 {
995 int k1 = invoke_dynamic_name_and_type_ref_index_at(index1);
996 int k2 = cp2->invoke_dynamic_name_and_type_ref_index_at(index2);
997 int i1 = invoke_dynamic_bootstrap_specifier_index(index1);
998 int i2 = cp2->invoke_dynamic_bootstrap_specifier_index(index2);
999 // separate statements and variables because CHECK_false is used
1000 bool match_entry = compare_entry_to(k1, cp2, k2, CHECK_false);
1001 bool match_operand = compare_operand_to(i1, cp2, i2, CHECK_false);
1002 return (match_entry && match_operand);
1003 } break;
1004
1005 case JVM_CONSTANT_String:
1006 {
1007 Symbol* s1 = unresolved_string_at(index1);
1008 Symbol* s2 = cp2->unresolved_string_at(index2);
1009 if (s1 == s2) {
1010 return true;
1011 }
1012 } break;
1013
1014 case JVM_CONSTANT_Utf8:
1015 {
1016 Symbol* s1 = symbol_at(index1);
1017 Symbol* s2 = cp2->symbol_at(index2);
1018 if (s1 == s2) {
1019 return true;
1020 }
1021 } break;
1022
1023 // Invalid is used as the tag for the second constant pool entry
1024 // occupied by JVM_CONSTANT_Double or JVM_CONSTANT_Long. It should
1025 // not be seen by itself.
1026 case JVM_CONSTANT_Invalid: // fall through
1027
1028 default:
1029 ShouldNotReachHere();
1030 break;
1031 }
1032
1033 return false;
1034 } // end compare_entry_to()
1035
1036
1037 // Resize the operands array with delta_len and delta_size.
1038 // Used in RedefineClasses for CP merge.
1039 void ConstantPool::resize_operands(int delta_len, int delta_size, TRAPS) {
1040 int old_len = operand_array_length(operands());
1041 int new_len = old_len + delta_len;
1042 int min_len = (delta_len > 0) ? old_len : new_len;
1043
1044 int old_size = operands()->length();
1045 int new_size = old_size + delta_size;
1046 int min_size = (delta_size > 0) ? old_size : new_size;
1047
1048 ClassLoaderData* loader_data = pool_holder()->class_loader_data();
1049 Array<u2>* new_ops = MetadataFactory::new_array<u2>(loader_data, new_size, CHECK);
1050
1051 // Set index in the resized array for existing elements only
1052 for (int idx = 0; idx < min_len; idx++) {
1053 int offset = operand_offset_at(idx); // offset in original array
1054 operand_offset_at_put(new_ops, idx, offset + 2*delta_len); // offset in resized array
1055 }
1056 // Copy the bootstrap specifiers only
1057 Copy::conjoint_memory_atomic(operands()->adr_at(2*old_len),
1058 new_ops->adr_at(2*new_len),
1059 (min_size - 2*min_len) * sizeof(u2));
1060 // Explicitly deallocate old operands array.
1061 // Note, it is not needed for 7u backport.
1062 if ( operands() != NULL) { // the safety check
1063 MetadataFactory::free_array<u2>(loader_data, operands());
1064 }
1065 set_operands(new_ops);
1066 } // end resize_operands()
1067
1068
1069 // Extend the operands array with the length and size of the ext_cp operands.
1070 // Used in RedefineClasses for CP merge.
1071 void ConstantPool::extend_operands(const constantPoolHandle& ext_cp, TRAPS) {
1072 int delta_len = operand_array_length(ext_cp->operands());
1073 if (delta_len == 0) {
1074 return; // nothing to do
1075 }
1076 int delta_size = ext_cp->operands()->length();
1077
1078 assert(delta_len > 0 && delta_size > 0, "extended operands array must be bigger");
1079
1080 if (operand_array_length(operands()) == 0) {
1081 ClassLoaderData* loader_data = pool_holder()->class_loader_data();
1082 Array<u2>* new_ops = MetadataFactory::new_array<u2>(loader_data, delta_size, CHECK);
1083 // The first element index defines the offset of second part
1084 operand_offset_at_put(new_ops, 0, 2*delta_len); // offset in new array
1085 set_operands(new_ops);
1086 } else {
1087 resize_operands(delta_len, delta_size, CHECK);
1088 }
1089
1090 } // end extend_operands()
1091
1092
1093 // Shrink the operands array to a smaller array with new_len length.
1094 // Used in RedefineClasses for CP merge.
1095 void ConstantPool::shrink_operands(int new_len, TRAPS) {
1096 int old_len = operand_array_length(operands());
1097 if (new_len == old_len) {
1098 return; // nothing to do
1099 }
1100 assert(new_len < old_len, "shrunken operands array must be smaller");
1101
1102 int free_base = operand_next_offset_at(new_len - 1);
1103 int delta_len = new_len - old_len;
1104 int delta_size = 2*delta_len + free_base - operands()->length();
1105
1106 resize_operands(delta_len, delta_size, CHECK);
1107
1108 } // end shrink_operands()
1109
1110
1111 void ConstantPool::copy_operands(const constantPoolHandle& from_cp,
1112 const constantPoolHandle& to_cp,
1113 TRAPS) {
1114
1115 int from_oplen = operand_array_length(from_cp->operands());
1116 int old_oplen = operand_array_length(to_cp->operands());
1117 if (from_oplen != 0) {
1118 ClassLoaderData* loader_data = to_cp->pool_holder()->class_loader_data();
1119 // append my operands to the target's operands array
1120 if (old_oplen == 0) {
1121 // Can't just reuse from_cp's operand list because of deallocation issues
1122 int len = from_cp->operands()->length();
1123 Array<u2>* new_ops = MetadataFactory::new_array<u2>(loader_data, len, CHECK);
1124 Copy::conjoint_memory_atomic(
1125 from_cp->operands()->adr_at(0), new_ops->adr_at(0), len * sizeof(u2));
1126 to_cp->set_operands(new_ops);
1127 } else {
1128 int old_len = to_cp->operands()->length();
1129 int from_len = from_cp->operands()->length();
1130 int old_off = old_oplen * sizeof(u2);
1131 int from_off = from_oplen * sizeof(u2);
1132 // Use the metaspace for the destination constant pool
1133 Array<u2>* new_operands = MetadataFactory::new_array<u2>(loader_data, old_len + from_len, CHECK);
1134 int fillp = 0, len = 0;
1135 // first part of dest
1136 Copy::conjoint_memory_atomic(to_cp->operands()->adr_at(0),
1137 new_operands->adr_at(fillp),
1138 (len = old_off) * sizeof(u2));
1139 fillp += len;
1140 // first part of src
1141 Copy::conjoint_memory_atomic(from_cp->operands()->adr_at(0),
1142 new_operands->adr_at(fillp),
1143 (len = from_off) * sizeof(u2));
1144 fillp += len;
1145 // second part of dest
1146 Copy::conjoint_memory_atomic(to_cp->operands()->adr_at(old_off),
1147 new_operands->adr_at(fillp),
1148 (len = old_len - old_off) * sizeof(u2));
1149 fillp += len;
1150 // second part of src
1151 Copy::conjoint_memory_atomic(from_cp->operands()->adr_at(from_off),
1152 new_operands->adr_at(fillp),
1153 (len = from_len - from_off) * sizeof(u2));
1154 fillp += len;
1155 assert(fillp == new_operands->length(), "");
1156
1157 // Adjust indexes in the first part of the copied operands array.
1158 for (int j = 0; j < from_oplen; j++) {
1159 int offset = operand_offset_at(new_operands, old_oplen + j);
1160 assert(offset == operand_offset_at(from_cp->operands(), j), "correct copy");
1161 offset += old_len; // every new tuple is preceded by old_len extra u2's
1162 operand_offset_at_put(new_operands, old_oplen + j, offset);
1163 }
1164
1165 // replace target operands array with combined array
1166 to_cp->set_operands(new_operands);
1167 }
1168 }
1169 } // end copy_operands()
1170
1171
1172 // Copy this constant pool's entries at start_i to end_i (inclusive)
1173 // to the constant pool to_cp's entries starting at to_i. A total of
1174 // (end_i - start_i) + 1 entries are copied.
1175 void ConstantPool::copy_cp_to_impl(const constantPoolHandle& from_cp, int start_i, int end_i,
1176 const constantPoolHandle& to_cp, int to_i, TRAPS) {
1177
1178
1179 int dest_i = to_i; // leave original alone for debug purposes
1180
1181 for (int src_i = start_i; src_i <= end_i; /* see loop bottom */ ) {
1182 copy_entry_to(from_cp, src_i, to_cp, dest_i, CHECK);
1183
1184 switch (from_cp->tag_at(src_i).value()) {
1185 case JVM_CONSTANT_Double:
1186 case JVM_CONSTANT_Long:
1187 // double and long take two constant pool entries
1188 src_i += 2;
1189 dest_i += 2;
1190 break;
1191
1192 default:
1193 // all others take one constant pool entry
1194 src_i++;
1195 dest_i++;
1196 break;
1197 }
1198 }
1199 copy_operands(from_cp, to_cp, CHECK);
1200
1201 } // end copy_cp_to_impl()
1202
1203
1204 // Copy this constant pool's entry at from_i to the constant pool
1205 // to_cp's entry at to_i.
1206 void ConstantPool::copy_entry_to(const constantPoolHandle& from_cp, int from_i,
1207 const constantPoolHandle& to_cp, int to_i,
1208 TRAPS) {
1209
1210 int tag = from_cp->tag_at(from_i).value();
1211 switch (tag) {
1212 case JVM_CONSTANT_Class:
1213 {
1214 Klass* k = from_cp->klass_at(from_i, CHECK);
1215 to_cp->klass_at_put(to_i, k);
1216 } break;
1217
1218 case JVM_CONSTANT_ClassIndex:
1219 {
1220 jint ki = from_cp->klass_index_at(from_i);
1221 to_cp->klass_index_at_put(to_i, ki);
1222 } break;
1223
1224 case JVM_CONSTANT_Double:
1225 {
1226 jdouble d = from_cp->double_at(from_i);
1227 to_cp->double_at_put(to_i, d);
1228 // double takes two constant pool entries so init second entry's tag
1229 to_cp->tag_at_put(to_i + 1, JVM_CONSTANT_Invalid);
1230 } break;
1231
1232 case JVM_CONSTANT_Fieldref:
1233 {
1234 int class_index = from_cp->uncached_klass_ref_index_at(from_i);
1235 int name_and_type_index = from_cp->uncached_name_and_type_ref_index_at(from_i);
1236 to_cp->field_at_put(to_i, class_index, name_and_type_index);
1237 } break;
1238
1239 case JVM_CONSTANT_Float:
1240 {
1241 jfloat f = from_cp->float_at(from_i);
1242 to_cp->float_at_put(to_i, f);
1243 } break;
1244
1245 case JVM_CONSTANT_Integer:
1246 {
1247 jint i = from_cp->int_at(from_i);
1248 to_cp->int_at_put(to_i, i);
1249 } break;
1250
1251 case JVM_CONSTANT_InterfaceMethodref:
1252 {
1253 int class_index = from_cp->uncached_klass_ref_index_at(from_i);
1254 int name_and_type_index = from_cp->uncached_name_and_type_ref_index_at(from_i);
1255 to_cp->interface_method_at_put(to_i, class_index, name_and_type_index);
1256 } break;
1257
1258 case JVM_CONSTANT_Long:
1259 {
1260 jlong l = from_cp->long_at(from_i);
1261 to_cp->long_at_put(to_i, l);
1262 // long takes two constant pool entries so init second entry's tag
1263 to_cp->tag_at_put(to_i + 1, JVM_CONSTANT_Invalid);
1264 } break;
1265
1266 case JVM_CONSTANT_Methodref:
1267 {
1268 int class_index = from_cp->uncached_klass_ref_index_at(from_i);
1269 int name_and_type_index = from_cp->uncached_name_and_type_ref_index_at(from_i);
1270 to_cp->method_at_put(to_i, class_index, name_and_type_index);
1271 } break;
1272
1273 case JVM_CONSTANT_NameAndType:
1274 {
1275 int name_ref_index = from_cp->name_ref_index_at(from_i);
1276 int signature_ref_index = from_cp->signature_ref_index_at(from_i);
1277 to_cp->name_and_type_at_put(to_i, name_ref_index, signature_ref_index);
1278 } break;
1279
1280 case JVM_CONSTANT_StringIndex:
1281 {
1282 jint si = from_cp->string_index_at(from_i);
1283 to_cp->string_index_at_put(to_i, si);
1284 } break;
1285
1286 case JVM_CONSTANT_UnresolvedClass:
1287 case JVM_CONSTANT_UnresolvedClassInError:
1288 {
1289 // Can be resolved after checking tag, so check the slot first.
1290 CPSlot entry = from_cp->slot_at(from_i);
1291 if (entry.is_resolved()) {
1292 assert(entry.get_klass()->is_klass(), "must be");
1293 // Already resolved
1294 to_cp->klass_at_put(to_i, entry.get_klass());
1295 } else {
1296 to_cp->unresolved_klass_at_put(to_i, entry.get_symbol());
1297 }
1298 } break;
1299
1300 case JVM_CONSTANT_String:
1301 {
1302 Symbol* s = from_cp->unresolved_string_at(from_i);
1303 to_cp->unresolved_string_at_put(to_i, s);
1304 } break;
1305
1306 case JVM_CONSTANT_Utf8:
1307 {
1308 Symbol* s = from_cp->symbol_at(from_i);
1309 // Need to increase refcount, the old one will be thrown away and deferenced
1310 s->increment_refcount();
1311 to_cp->symbol_at_put(to_i, s);
1312 } break;
1313
1314 case JVM_CONSTANT_MethodType:
1315 case JVM_CONSTANT_MethodTypeInError:
1316 {
1317 jint k = from_cp->method_type_index_at_error_ok(from_i);
1318 to_cp->method_type_index_at_put(to_i, k);
1319 } break;
1320
1321 case JVM_CONSTANT_MethodHandle:
1322 case JVM_CONSTANT_MethodHandleInError:
1323 {
1324 int k1 = from_cp->method_handle_ref_kind_at_error_ok(from_i);
1325 int k2 = from_cp->method_handle_index_at_error_ok(from_i);
1326 to_cp->method_handle_index_at_put(to_i, k1, k2);
1327 } break;
1328
1329 case JVM_CONSTANT_InvokeDynamic:
1330 {
1331 int k1 = from_cp->invoke_dynamic_bootstrap_specifier_index(from_i);
1332 int k2 = from_cp->invoke_dynamic_name_and_type_ref_index_at(from_i);
1333 k1 += operand_array_length(to_cp->operands()); // to_cp might already have operands
1334 to_cp->invoke_dynamic_at_put(to_i, k1, k2);
1335 } break;
1336
1337 // Invalid is used as the tag for the second constant pool entry
1338 // occupied by JVM_CONSTANT_Double or JVM_CONSTANT_Long. It should
1339 // not be seen by itself.
1340 case JVM_CONSTANT_Invalid: // fall through
1341
1342 default:
1343 {
1344 ShouldNotReachHere();
1345 } break;
1346 }
1347 } // end copy_entry_to()
1348
1349
1350 // Search constant pool search_cp for an entry that matches this
1351 // constant pool's entry at pattern_i. Returns the index of a
1352 // matching entry or zero (0) if there is no matching entry.
1353 int ConstantPool::find_matching_entry(int pattern_i,
1354 const constantPoolHandle& search_cp, TRAPS) {
1355
1356 // index zero (0) is not used
1357 for (int i = 1; i < search_cp->length(); i++) {
1358 bool found = compare_entry_to(pattern_i, search_cp, i, CHECK_0);
1359 if (found) {
1360 return i;
1361 }
1362 }
1363
1364 return 0; // entry not found; return unused index zero (0)
1365 } // end find_matching_entry()
1366
1367
1368 // Compare this constant pool's bootstrap specifier at idx1 to the constant pool
1369 // cp2's bootstrap specifier at idx2.
1370 bool ConstantPool::compare_operand_to(int idx1, const constantPoolHandle& cp2, int idx2, TRAPS) {
1371 int k1 = operand_bootstrap_method_ref_index_at(idx1);
1372 int k2 = cp2->operand_bootstrap_method_ref_index_at(idx2);
1373 bool match = compare_entry_to(k1, cp2, k2, CHECK_false);
1374
1375 if (!match) {
1376 return false;
1377 }
1378 int argc = operand_argument_count_at(idx1);
1379 if (argc == cp2->operand_argument_count_at(idx2)) {
1380 for (int j = 0; j < argc; j++) {
1381 k1 = operand_argument_index_at(idx1, j);
1382 k2 = cp2->operand_argument_index_at(idx2, j);
1383 match = compare_entry_to(k1, cp2, k2, CHECK_false);
1384 if (!match) {
1385 return false;
1386 }
1387 }
1388 return true; // got through loop; all elements equal
1389 }
1390 return false;
1391 } // end compare_operand_to()
1392
1393 // Search constant pool search_cp for a bootstrap specifier that matches
1394 // this constant pool's bootstrap specifier at pattern_i index.
1395 // Return the index of a matching bootstrap specifier or (-1) if there is no match.
1396 int ConstantPool::find_matching_operand(int pattern_i,
1397 const constantPoolHandle& search_cp, int search_len, TRAPS) {
1398 for (int i = 0; i < search_len; i++) {
1399 bool found = compare_operand_to(pattern_i, search_cp, i, CHECK_(-1));
1400 if (found) {
1401 return i;
1402 }
1403 }
1404 return -1; // bootstrap specifier not found; return unused index (-1)
1405 } // end find_matching_operand()
1406
1407
1408 #ifndef PRODUCT
1409
1410 const char* ConstantPool::printable_name_at(int which) {
1411
1412 constantTag tag = tag_at(which);
1413
1414 if (tag.is_string()) {
1415 return string_at_noresolve(which);
1416 } else if (tag.is_klass() || tag.is_unresolved_klass()) {
1417 return klass_name_at(which)->as_C_string();
1418 } else if (tag.is_symbol()) {
1419 return symbol_at(which)->as_C_string();
1420 }
1421 return "";
1422 }
1423
1424 #endif // PRODUCT
1425
1426
1427 // JVMTI GetConstantPool support
1428
1429 // For debugging of constant pool
1430 const bool debug_cpool = false;
1431
1432 #define DBG(code) do { if (debug_cpool) { (code); } } while(0)
1433
1434 static void print_cpool_bytes(jint cnt, u1 *bytes) {
1435 const char* WARN_MSG = "Must not be such entry!";
1436 jint size = 0;
1437 u2 idx1, idx2;
1438
1439 for (jint idx = 1; idx < cnt; idx++) {
1440 jint ent_size = 0;
1441 u1 tag = *bytes++;
1442 size++; // count tag
1443
1444 printf("const #%03d, tag: %02d ", idx, tag);
1445 switch(tag) {
1446 case JVM_CONSTANT_Invalid: {
1447 printf("Invalid");
1448 break;
1449 }
1450 case JVM_CONSTANT_Unicode: {
1451 printf("Unicode %s", WARN_MSG);
1452 break;
1453 }
1454 case JVM_CONSTANT_Utf8: {
1455 u2 len = Bytes::get_Java_u2(bytes);
1456 char str[128];
1457 if (len > 127) {
1458 len = 127;
1459 }
1460 strncpy(str, (char *) (bytes+2), len);
1461 str[len] = '\0';
1462 printf("Utf8 \"%s\"", str);
1463 ent_size = 2 + len;
1464 break;
1465 }
1466 case JVM_CONSTANT_Integer: {
1467 u4 val = Bytes::get_Java_u4(bytes);
1468 printf("int %d", *(int *) &val);
1469 ent_size = 4;
1470 break;
1471 }
1472 case JVM_CONSTANT_Float: {
1473 u4 val = Bytes::get_Java_u4(bytes);
1474 printf("float %5.3ff", *(float *) &val);
1475 ent_size = 4;
1476 break;
1477 }
1478 case JVM_CONSTANT_Long: {
1479 u8 val = Bytes::get_Java_u8(bytes);
1480 printf("long " INT64_FORMAT, (int64_t) *(jlong *) &val);
1481 ent_size = 8;
1482 idx++; // Long takes two cpool slots
1483 break;
1484 }
1485 case JVM_CONSTANT_Double: {
1486 u8 val = Bytes::get_Java_u8(bytes);
1487 printf("double %5.3fd", *(jdouble *)&val);
1488 ent_size = 8;
1489 idx++; // Double takes two cpool slots
1490 break;
1491 }
1492 case JVM_CONSTANT_Class: {
1493 idx1 = Bytes::get_Java_u2(bytes);
1494 printf("class #%03d", idx1);
1495 ent_size = 2;
1496 break;
1497 }
1498 case JVM_CONSTANT_String: {
1499 idx1 = Bytes::get_Java_u2(bytes);
1500 printf("String #%03d", idx1);
1501 ent_size = 2;
1502 break;
1503 }
1504 case JVM_CONSTANT_Fieldref: {
1505 idx1 = Bytes::get_Java_u2(bytes);
1506 idx2 = Bytes::get_Java_u2(bytes+2);
1507 printf("Field #%03d, #%03d", (int) idx1, (int) idx2);
1508 ent_size = 4;
1509 break;
1510 }
1511 case JVM_CONSTANT_Methodref: {
1512 idx1 = Bytes::get_Java_u2(bytes);
1513 idx2 = Bytes::get_Java_u2(bytes+2);
1514 printf("Method #%03d, #%03d", idx1, idx2);
1515 ent_size = 4;
1516 break;
1517 }
1518 case JVM_CONSTANT_InterfaceMethodref: {
1519 idx1 = Bytes::get_Java_u2(bytes);
1520 idx2 = Bytes::get_Java_u2(bytes+2);
1521 printf("InterfMethod #%03d, #%03d", idx1, idx2);
1522 ent_size = 4;
1523 break;
1524 }
1525 case JVM_CONSTANT_NameAndType: {
1526 idx1 = Bytes::get_Java_u2(bytes);
1527 idx2 = Bytes::get_Java_u2(bytes+2);
1528 printf("NameAndType #%03d, #%03d", idx1, idx2);
1529 ent_size = 4;
1530 break;
1531 }
1532 case JVM_CONSTANT_ClassIndex: {
1533 printf("ClassIndex %s", WARN_MSG);
1534 break;
1535 }
1536 case JVM_CONSTANT_UnresolvedClass: {
1537 printf("UnresolvedClass: %s", WARN_MSG);
1538 break;
1539 }
1540 case JVM_CONSTANT_UnresolvedClassInError: {
1541 printf("UnresolvedClassInErr: %s", WARN_MSG);
1542 break;
1543 }
1544 case JVM_CONSTANT_StringIndex: {
1545 printf("StringIndex: %s", WARN_MSG);
1546 break;
1547 }
1548 }
1549 printf(";\n");
1550 bytes += ent_size;
1551 size += ent_size;
1552 }
1553 printf("Cpool size: %d\n", size);
1554 fflush(0);
1555 return;
1556 } /* end print_cpool_bytes */
1557
1558
1559 // Returns size of constant pool entry.
1560 jint ConstantPool::cpool_entry_size(jint idx) {
1561 switch(tag_at(idx).value()) {
1562 case JVM_CONSTANT_Invalid:
1563 case JVM_CONSTANT_Unicode:
1564 return 1;
1565
1566 case JVM_CONSTANT_Utf8:
1567 return 3 + symbol_at(idx)->utf8_length();
1568
1569 case JVM_CONSTANT_Class:
1570 case JVM_CONSTANT_String:
1571 case JVM_CONSTANT_ClassIndex:
1572 case JVM_CONSTANT_UnresolvedClass:
1573 case JVM_CONSTANT_UnresolvedClassInError:
1574 case JVM_CONSTANT_StringIndex:
1575 case JVM_CONSTANT_MethodType:
1576 case JVM_CONSTANT_MethodTypeInError:
1577 return 3;
1578
1579 case JVM_CONSTANT_MethodHandle:
1580 case JVM_CONSTANT_MethodHandleInError:
1581 return 4; //tag, ref_kind, ref_index
1582
1583 case JVM_CONSTANT_Integer:
1584 case JVM_CONSTANT_Float:
1585 case JVM_CONSTANT_Fieldref:
1586 case JVM_CONSTANT_Methodref:
1587 case JVM_CONSTANT_InterfaceMethodref:
1588 case JVM_CONSTANT_NameAndType:
1589 return 5;
1590
1591 case JVM_CONSTANT_InvokeDynamic:
1592 // u1 tag, u2 bsm, u2 nt
1593 return 5;
1594
1595 case JVM_CONSTANT_Long:
1596 case JVM_CONSTANT_Double:
1597 return 9;
1598 }
1599 assert(false, "cpool_entry_size: Invalid constant pool entry tag");
1600 return 1;
1601 } /* end cpool_entry_size */
1602
1603
1604 // SymbolHashMap is used to find a constant pool index from a string.
1605 // This function fills in SymbolHashMaps, one for utf8s and one for
1606 // class names, returns size of the cpool raw bytes.
1607 jint ConstantPool::hash_entries_to(SymbolHashMap *symmap,
1608 SymbolHashMap *classmap) {
1609 jint size = 0;
1610
1611 for (u2 idx = 1; idx < length(); idx++) {
1612 u2 tag = tag_at(idx).value();
1613 size += cpool_entry_size(idx);
1614
1615 switch(tag) {
1616 case JVM_CONSTANT_Utf8: {
1617 Symbol* sym = symbol_at(idx);
1618 symmap->add_entry(sym, idx);
1619 DBG(printf("adding symbol entry %s = %d\n", sym->as_utf8(), idx));
1620 break;
1621 }
1622 case JVM_CONSTANT_Class:
1623 case JVM_CONSTANT_UnresolvedClass:
1624 case JVM_CONSTANT_UnresolvedClassInError: {
1625 Symbol* sym = klass_name_at(idx);
1626 classmap->add_entry(sym, idx);
1627 DBG(printf("adding class entry %s = %d\n", sym->as_utf8(), idx));
1628 break;
1629 }
1630 case JVM_CONSTANT_Long:
1631 case JVM_CONSTANT_Double: {
1632 idx++; // Both Long and Double take two cpool slots
1633 break;
1634 }
1635 }
1636 }
1637 return size;
1638 } /* end hash_utf8_entries_to */
1639
1640
1641 // Copy cpool bytes.
1642 // Returns:
1643 // 0, in case of OutOfMemoryError
1644 // -1, in case of internal error
1645 // > 0, count of the raw cpool bytes that have been copied
1646 int ConstantPool::copy_cpool_bytes(int cpool_size,
1647 SymbolHashMap* tbl,
1648 unsigned char *bytes) {
1649 u2 idx1, idx2;
1650 jint size = 0;
1651 jint cnt = length();
1652 unsigned char *start_bytes = bytes;
1653
1654 for (jint idx = 1; idx < cnt; idx++) {
1655 u1 tag = tag_at(idx).value();
1656 jint ent_size = cpool_entry_size(idx);
1657
1658 assert(size + ent_size <= cpool_size, "Size mismatch");
1659
1660 *bytes = tag;
1661 DBG(printf("#%03hd tag=%03hd, ", idx, tag));
1662 switch(tag) {
1663 case JVM_CONSTANT_Invalid: {
1664 DBG(printf("JVM_CONSTANT_Invalid"));
1665 break;
1666 }
1667 case JVM_CONSTANT_Unicode: {
1668 assert(false, "Wrong constant pool tag: JVM_CONSTANT_Unicode");
1669 DBG(printf("JVM_CONSTANT_Unicode"));
1670 break;
1671 }
1672 case JVM_CONSTANT_Utf8: {
1673 Symbol* sym = symbol_at(idx);
1674 char* str = sym->as_utf8();
1675 // Warning! It's crashing on x86 with len = sym->utf8_length()
1676 int len = (int) strlen(str);
1677 Bytes::put_Java_u2((address) (bytes+1), (u2) len);
1678 for (int i = 0; i < len; i++) {
1679 bytes[3+i] = (u1) str[i];
1680 }
1681 DBG(printf("JVM_CONSTANT_Utf8: %s ", str));
1682 break;
1683 }
1684 case JVM_CONSTANT_Integer: {
1685 jint val = int_at(idx);
1686 Bytes::put_Java_u4((address) (bytes+1), *(u4*)&val);
1687 break;
1688 }
1689 case JVM_CONSTANT_Float: {
1690 jfloat val = float_at(idx);
1691 Bytes::put_Java_u4((address) (bytes+1), *(u4*)&val);
1692 break;
1693 }
1694 case JVM_CONSTANT_Long: {
1695 jlong val = long_at(idx);
1696 Bytes::put_Java_u8((address) (bytes+1), *(u8*)&val);
1697 idx++; // Long takes two cpool slots
1698 break;
1699 }
1700 case JVM_CONSTANT_Double: {
1701 jdouble val = double_at(idx);
1702 Bytes::put_Java_u8((address) (bytes+1), *(u8*)&val);
1703 idx++; // Double takes two cpool slots
1704 break;
1705 }
1706 case JVM_CONSTANT_Class:
1707 case JVM_CONSTANT_UnresolvedClass:
1708 case JVM_CONSTANT_UnresolvedClassInError: {
1709 *bytes = JVM_CONSTANT_Class;
1710 Symbol* sym = klass_name_at(idx);
1711 idx1 = tbl->symbol_to_value(sym);
1712 assert(idx1 != 0, "Have not found a hashtable entry");
1713 Bytes::put_Java_u2((address) (bytes+1), idx1);
1714 DBG(printf("JVM_CONSTANT_Class: idx=#%03hd, %s", idx1, sym->as_utf8()));
1715 break;
1716 }
1717 case JVM_CONSTANT_String: {
1718 *bytes = JVM_CONSTANT_String;
1719 Symbol* sym = unresolved_string_at(idx);
1720 idx1 = tbl->symbol_to_value(sym);
1721 assert(idx1 != 0, "Have not found a hashtable entry");
1722 Bytes::put_Java_u2((address) (bytes+1), idx1);
1723 DBG(printf("JVM_CONSTANT_String: idx=#%03hd, %s", idx1, sym->as_utf8()));
1724 break;
1725 }
1726 case JVM_CONSTANT_Fieldref:
1727 case JVM_CONSTANT_Methodref:
1728 case JVM_CONSTANT_InterfaceMethodref: {
1729 idx1 = uncached_klass_ref_index_at(idx);
1730 idx2 = uncached_name_and_type_ref_index_at(idx);
1731 Bytes::put_Java_u2((address) (bytes+1), idx1);
1732 Bytes::put_Java_u2((address) (bytes+3), idx2);
1733 DBG(printf("JVM_CONSTANT_Methodref: %hd %hd", idx1, idx2));
1734 break;
1735 }
1736 case JVM_CONSTANT_NameAndType: {
1737 idx1 = name_ref_index_at(idx);
1738 idx2 = signature_ref_index_at(idx);
1739 Bytes::put_Java_u2((address) (bytes+1), idx1);
1740 Bytes::put_Java_u2((address) (bytes+3), idx2);
1741 DBG(printf("JVM_CONSTANT_NameAndType: %hd %hd", idx1, idx2));
1742 break;
1743 }
1744 case JVM_CONSTANT_ClassIndex: {
1745 *bytes = JVM_CONSTANT_Class;
1746 idx1 = klass_index_at(idx);
1747 Bytes::put_Java_u2((address) (bytes+1), idx1);
1748 DBG(printf("JVM_CONSTANT_ClassIndex: %hd", idx1));
1749 break;
1750 }
1751 case JVM_CONSTANT_StringIndex: {
1752 *bytes = JVM_CONSTANT_String;
1753 idx1 = string_index_at(idx);
1754 Bytes::put_Java_u2((address) (bytes+1), idx1);
1755 DBG(printf("JVM_CONSTANT_StringIndex: %hd", idx1));
1756 break;
1757 }
1758 case JVM_CONSTANT_MethodHandle:
1759 case JVM_CONSTANT_MethodHandleInError: {
1760 *bytes = JVM_CONSTANT_MethodHandle;
1761 int kind = method_handle_ref_kind_at_error_ok(idx);
1762 idx1 = method_handle_index_at_error_ok(idx);
1763 *(bytes+1) = (unsigned char) kind;
1764 Bytes::put_Java_u2((address) (bytes+2), idx1);
1765 DBG(printf("JVM_CONSTANT_MethodHandle: %d %hd", kind, idx1));
1766 break;
1767 }
1768 case JVM_CONSTANT_MethodType:
1769 case JVM_CONSTANT_MethodTypeInError: {
1770 *bytes = JVM_CONSTANT_MethodType;
1771 idx1 = method_type_index_at_error_ok(idx);
1772 Bytes::put_Java_u2((address) (bytes+1), idx1);
1773 DBG(printf("JVM_CONSTANT_MethodType: %hd", idx1));
1774 break;
1775 }
1776 case JVM_CONSTANT_InvokeDynamic: {
1777 *bytes = tag;
1778 idx1 = extract_low_short_from_int(*int_at_addr(idx));
1779 idx2 = extract_high_short_from_int(*int_at_addr(idx));
1780 assert(idx2 == invoke_dynamic_name_and_type_ref_index_at(idx), "correct half of u4");
1781 Bytes::put_Java_u2((address) (bytes+1), idx1);
1782 Bytes::put_Java_u2((address) (bytes+3), idx2);
1783 DBG(printf("JVM_CONSTANT_InvokeDynamic: %hd %hd", idx1, idx2));
1784 break;
1785 }
1786 }
1787 DBG(printf("\n"));
1788 bytes += ent_size;
1789 size += ent_size;
1790 }
1791 assert(size == cpool_size, "Size mismatch");
1792
1793 // Keep temorarily for debugging until it's stable.
1794 DBG(print_cpool_bytes(cnt, start_bytes));
1795 return (int)(bytes - start_bytes);
1796 } /* end copy_cpool_bytes */
1797
1798 #undef DBG
1799
1800
1801 void ConstantPool::set_on_stack(const bool value) {
1802 if (value) {
1803 // Only record if it's not already set.
1804 if (!on_stack()) {
1805 _flags |= _on_stack;
1806 MetadataOnStackMark::record(this);
1807 }
1808 } else {
1809 // Clearing is done single-threadedly.
1810 _flags &= ~_on_stack;
1811 }
1812 }
1813
1814 // JSR 292 support for patching constant pool oops after the class is linked and
1815 // the oop array for resolved references are created.
1816 // We can't do this during classfile parsing, which is how the other indexes are
1817 // patched. The other patches are applied early for some error checking
1818 // so only defer the pseudo_strings.
1819 void ConstantPool::patch_resolved_references(GrowableArray<Handle>* cp_patches) {
1820 for (int index = 1; index < cp_patches->length(); index++) { // Index 0 is unused
1821 Handle patch = cp_patches->at(index);
1822 if (patch.not_null()) {
1823 assert (tag_at(index).is_string(), "should only be string left");
1824 // Patching a string means pre-resolving it.
1825 // The spelling in the constant pool is ignored.
1826 // The constant reference may be any object whatever.
1827 // If it is not a real interned string, the constant is referred
1828 // to as a "pseudo-string", and must be presented to the CP
1829 // explicitly, because it may require scavenging.
1830 int obj_index = cp_to_object_index(index);
1831 pseudo_string_at_put(index, obj_index, patch());
1832 DEBUG_ONLY(cp_patches->at_put(index, Handle());)
1833 }
1834 }
1835 #ifdef ASSERT
1836 // Ensure that all the patches have been used.
1837 for (int index = 0; index < cp_patches->length(); index++) {
1838 assert(cp_patches->at(index).is_null(),
1839 "Unused constant pool patch at %d in class file %s",
1840 index,
1841 pool_holder()->external_name());
1842 }
1843 #endif // ASSERT
1844 }
1845
1846 #ifndef PRODUCT
1847
1848 // CompileTheWorld support. Preload all classes loaded references in the passed in constantpool
1849 void ConstantPool::preload_and_initialize_all_classes(ConstantPool* obj, TRAPS) {
1850 guarantee(obj->is_constantPool(), "object must be constant pool");
1851 constantPoolHandle cp(THREAD, (ConstantPool*)obj);
1852 guarantee(cp->pool_holder() != NULL, "must be fully loaded");
1853
1854 for (int i = 0; i< cp->length(); i++) {
1855 if (cp->tag_at(i).is_unresolved_klass()) {
1856 // This will force loading of the class
1857 Klass* klass = cp->klass_at(i, CHECK);
1858 if (klass->is_instance_klass()) {
1859 // Force initialization of class
1860 InstanceKlass::cast(klass)->initialize(CHECK);
1861 }
1862 }
1863 }
1864 }
1865
1866 #endif
1867
1868
1869 // Printing
1870
1871 void ConstantPool::print_on(outputStream* st) const {
1872 assert(is_constantPool(), "must be constantPool");
1873 st->print_cr("%s", internal_name());
1874 if (flags() != 0) {
1875 st->print(" - flags: 0x%x", flags());
1876 if (has_preresolution()) st->print(" has_preresolution");
1877 if (on_stack()) st->print(" on_stack");
1878 st->cr();
1879 }
1880 if (pool_holder() != NULL) {
1881 st->print_cr(" - holder: " INTPTR_FORMAT, p2i(pool_holder()));
1882 }
1883 st->print_cr(" - cache: " INTPTR_FORMAT, p2i(cache()));
1884 st->print_cr(" - resolved_references: " INTPTR_FORMAT, p2i(resolved_references()));
1885 st->print_cr(" - reference_map: " INTPTR_FORMAT, p2i(reference_map()));
1886
1887 for (int index = 1; index < length(); index++) { // Index 0 is unused
1888 ((ConstantPool*)this)->print_entry_on(index, st);
1889 switch (tag_at(index).value()) {
1890 case JVM_CONSTANT_Long :
1891 case JVM_CONSTANT_Double :
1892 index++; // Skip entry following eigth-byte constant
1893 }
1894
1895 }
1896 st->cr();
1897 }
1898
1899 // Print one constant pool entry
1900 void ConstantPool::print_entry_on(const int index, outputStream* st) {
1901 EXCEPTION_MARK;
1902 st->print(" - %3d : ", index);
1903 tag_at(index).print_on(st);
1904 st->print(" : ");
1905 switch (tag_at(index).value()) {
1906 case JVM_CONSTANT_Class :
1907 { Klass* k = klass_at(index, CATCH);
1908 guarantee(k != NULL, "need klass");
1909 k->print_value_on(st);
1910 st->print(" {" PTR_FORMAT "}", p2i(k));
1911 }
1912 break;
1913 case JVM_CONSTANT_Fieldref :
1914 case JVM_CONSTANT_Methodref :
1915 case JVM_CONSTANT_InterfaceMethodref :
1916 st->print("klass_index=%d", uncached_klass_ref_index_at(index));
1917 st->print(" name_and_type_index=%d", uncached_name_and_type_ref_index_at(index));
1918 break;
1919 case JVM_CONSTANT_String :
1920 if (is_pseudo_string_at(index)) {
1921 oop anObj = pseudo_string_at(index);
1922 anObj->print_value_on(st);
1923 st->print(" {" PTR_FORMAT "}", p2i(anObj));
1924 } else {
1925 unresolved_string_at(index)->print_value_on(st);
1926 }
1927 break;
1928 case JVM_CONSTANT_Integer :
1929 st->print("%d", int_at(index));
1930 break;
1931 case JVM_CONSTANT_Float :
1932 st->print("%f", float_at(index));
1933 break;
1934 case JVM_CONSTANT_Long :
1935 st->print_jlong(long_at(index));
1936 break;
1937 case JVM_CONSTANT_Double :
1938 st->print("%lf", double_at(index));
1939 break;
1940 case JVM_CONSTANT_NameAndType :
1941 st->print("name_index=%d", name_ref_index_at(index));
1942 st->print(" signature_index=%d", signature_ref_index_at(index));
1943 break;
1944 case JVM_CONSTANT_Utf8 :
1945 symbol_at(index)->print_value_on(st);
1946 break;
1947 case JVM_CONSTANT_UnresolvedClass : // fall-through
1948 case JVM_CONSTANT_UnresolvedClassInError: {
1949 CPSlot entry = slot_at(index);
1950 if (entry.is_resolved()) {
1951 entry.get_klass()->print_value_on(st);
1952 } else {
1953 entry.get_symbol()->print_value_on(st);
1954 }
1955 }
1956 break;
1957 case JVM_CONSTANT_MethodHandle :
1958 case JVM_CONSTANT_MethodHandleInError :
1959 st->print("ref_kind=%d", method_handle_ref_kind_at_error_ok(index));
1960 st->print(" ref_index=%d", method_handle_index_at_error_ok(index));
1961 break;
1962 case JVM_CONSTANT_MethodType :
1963 case JVM_CONSTANT_MethodTypeInError :
1964 st->print("signature_index=%d", method_type_index_at_error_ok(index));
1965 break;
1966 case JVM_CONSTANT_InvokeDynamic :
1967 {
1968 st->print("bootstrap_method_index=%d", invoke_dynamic_bootstrap_method_ref_index_at(index));
1969 st->print(" name_and_type_index=%d", invoke_dynamic_name_and_type_ref_index_at(index));
1970 int argc = invoke_dynamic_argument_count_at(index);
1971 if (argc > 0) {
1972 for (int arg_i = 0; arg_i < argc; arg_i++) {
1973 int arg = invoke_dynamic_argument_index_at(index, arg_i);
1974 st->print((arg_i == 0 ? " arguments={%d" : ", %d"), arg);
1975 }
1976 st->print("}");
1977 }
1978 }
1979 break;
1980 default:
1981 ShouldNotReachHere();
1982 break;
1983 }
1984 st->cr();
1985 }
1986
1987 void ConstantPool::print_value_on(outputStream* st) const {
1988 assert(is_constantPool(), "must be constantPool");
1989 st->print("constant pool [%d]", length());
1990 if (has_preresolution()) st->print("/preresolution");
1991 if (operands() != NULL) st->print("/operands[%d]", operands()->length());
1992 print_address_on(st);
1993 st->print(" for ");
1994 pool_holder()->print_value_on(st);
1995 if (pool_holder() != NULL) {
1996 bool extra = (pool_holder()->constants() != this);
1997 if (extra) st->print(" (extra)");
1998 }
1999 if (cache() != NULL) {
2000 st->print(" cache=" PTR_FORMAT, p2i(cache()));
2001 }
2002 }
2003
2004 #if INCLUDE_SERVICES
2005 // Size Statistics
2006 void ConstantPool::collect_statistics(KlassSizeStats *sz) const {
2007 sz->_cp_all_bytes += (sz->_cp_bytes = sz->count(this));
2008 sz->_cp_all_bytes += (sz->_cp_tags_bytes = sz->count_array(tags()));
2009 sz->_cp_all_bytes += (sz->_cp_cache_bytes = sz->count(cache()));
2010 sz->_cp_all_bytes += (sz->_cp_operands_bytes = sz->count_array(operands()));
2011 sz->_cp_all_bytes += (sz->_cp_refmap_bytes = sz->count_array(reference_map()));
2012
2013 sz->_ro_bytes += sz->_cp_operands_bytes + sz->_cp_tags_bytes +
2014 sz->_cp_refmap_bytes;
2015 sz->_rw_bytes += sz->_cp_bytes + sz->_cp_cache_bytes;
2016 }
2017 #endif // INCLUDE_SERVICES
2018
2019 // Verification
2020
2021 void ConstantPool::verify_on(outputStream* st) {
2022 guarantee(is_constantPool(), "object must be constant pool");
2023 for (int i = 0; i< length(); i++) {
2024 constantTag tag = tag_at(i);
2025 CPSlot entry = slot_at(i);
2026 if (tag.is_klass()) {
2027 if (entry.is_resolved()) {
2028 guarantee(entry.get_klass()->is_klass(), "should be klass");
2029 }
2030 } else if (tag.is_unresolved_klass()) {
2031 if (entry.is_resolved()) {
2032 guarantee(entry.get_klass()->is_klass(), "should be klass");
2033 }
2034 } else if (tag.is_symbol()) {
2035 guarantee(entry.get_symbol()->refcount() != 0, "should have nonzero reference count");
2036 } else if (tag.is_string()) {
2037 guarantee(entry.get_symbol()->refcount() != 0, "should have nonzero reference count");
2038 }
2039 }
2040 if (cache() != NULL) {
2041 // Note: cache() can be NULL before a class is completely setup or
2042 // in temporary constant pools used during constant pool merging
2043 guarantee(cache()->is_constantPoolCache(), "should be constant pool cache");
2044 }
2045 if (pool_holder() != NULL) {
2046 // Note: pool_holder() can be NULL in temporary constant pools
2047 // used during constant pool merging
2048 guarantee(pool_holder()->is_klass(), "should be klass");
2049 }
2050 }
2051
2052
2053 void SymbolHashMap::add_entry(Symbol* sym, u2 value) {
2054 char *str = sym->as_utf8();
2055 unsigned int hash = compute_hash(str, sym->utf8_length());
2056 unsigned int index = hash % table_size();
2057
2058 // check if already in map
2059 // we prefer the first entry since it is more likely to be what was used in
2060 // the class file
2061 for (SymbolHashMapEntry *en = bucket(index); en != NULL; en = en->next()) {
2062 assert(en->symbol() != NULL, "SymbolHashMapEntry symbol is NULL");
2063 if (en->hash() == hash && en->symbol() == sym) {
2064 return; // already there
2065 }
2066 }
2067
2068 SymbolHashMapEntry* entry = new SymbolHashMapEntry(hash, sym, value);
2069 entry->set_next(bucket(index));
2070 _buckets[index].set_entry(entry);
2071 assert(entry->symbol() != NULL, "SymbolHashMapEntry symbol is NULL");
2072 }
2073
2074 SymbolHashMapEntry* SymbolHashMap::find_entry(Symbol* sym) {
2075 assert(sym != NULL, "SymbolHashMap::find_entry - symbol is NULL");
2076 char *str = sym->as_utf8();
2077 int len = sym->utf8_length();
2078 unsigned int hash = SymbolHashMap::compute_hash(str, len);
2079 unsigned int index = hash % table_size();
2080 for (SymbolHashMapEntry *en = bucket(index); en != NULL; en = en->next()) {
2081 assert(en->symbol() != NULL, "SymbolHashMapEntry symbol is NULL");
2082 if (en->hash() == hash && en->symbol() == sym) {
2083 return en;
2084 }
2085 }
2086 return NULL;
2087 }