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