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_debug(classresolve)("%s %s %s:%d",
 212                  this_cp->pool_holder()->external_name(),
 213                  k->external_name(), source_file, line_number);
 214     } else {
 215       log_debug(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   // logging for classresolve tag.
 285   trace_class_resolution(this_cp, k);
 286 
 287   this_cp->klass_at_put(which, k());
 288   entry = this_cp->resolved_klass_at(which);
 289   assert(entry.is_resolved() && entry.get_klass()->is_klass(), "must be resolved at this point");
 290   return entry.get_klass();
 291 }
 292 
 293 
 294 // Does not update ConstantPool* - to avoid any exception throwing. Used
 295 // by compiler and exception handling.  Also used to avoid classloads for
 296 // instanceof operations. Returns NULL if the class has not been loaded or
 297 // if the verification of constant pool failed
 298 Klass* ConstantPool::klass_at_if_loaded(const constantPoolHandle& this_cp, int which) {
 299   CPSlot entry = this_cp->slot_at(which);
 300   if (entry.is_resolved()) {
 301     assert(entry.get_klass()->is_klass(), "must be");
 302     return entry.get_klass();
 303   } else {
 304     assert(entry.is_unresolved(), "must be either symbol or klass");
 305     Thread *thread = Thread::current();
 306     Symbol* name = entry.get_symbol();
 307     oop loader = this_cp->pool_holder()->class_loader();
 308     oop protection_domain = this_cp->pool_holder()->protection_domain();
 309     Handle h_prot (thread, protection_domain);
 310     Handle h_loader (thread, loader);
 311     Klass* k = SystemDictionary::find(name, h_loader, h_prot, thread);
 312 
 313     if (k != NULL) {
 314       // Make sure that resolving is legal
 315       EXCEPTION_MARK;
 316       KlassHandle klass(THREAD, k);
 317       // return NULL if verification fails
 318       verify_constant_pool_resolve(this_cp, klass, THREAD);
 319       if (HAS_PENDING_EXCEPTION) {
 320         CLEAR_PENDING_EXCEPTION;
 321         return NULL;
 322       }
 323       return klass();
 324     } else {
 325       return k;
 326     }
 327   }
 328 }
 329 
 330 
 331 Klass* ConstantPool::klass_ref_at_if_loaded(const constantPoolHandle& this_cp, int which) {
 332   return klass_at_if_loaded(this_cp, this_cp->klass_ref_index_at(which));
 333 }
 334 
 335 
 336 Method* ConstantPool::method_at_if_loaded(const constantPoolHandle& cpool,
 337                                                    int which) {
 338   if (cpool->cache() == NULL)  return NULL;  // nothing to load yet
 339   int cache_index = decode_cpcache_index(which, true);
 340   if (!(cache_index >= 0 && cache_index < cpool->cache()->length())) {
 341     // FIXME: should be an assert
 342     if (PrintMiscellaneous && (Verbose||WizardMode)) {
 343       tty->print_cr("bad operand %d in:", which); cpool->print();
 344     }
 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 resolved_references
 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       if (PrintMiscellaneous)
 675         tty->print_cr("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       KlassHandle callee;
 679       { Klass* k = klass_at_impl(this_cp, callee_index, true, CHECK_NULL);
 680         callee = KlassHandle(THREAD, k);
 681       }
 682       KlassHandle klass(THREAD, this_cp->pool_holder());
 683       Handle value = SystemDictionary::link_method_handle_constant(klass, ref_kind,
 684                                                                    callee, name, signature,
 685                                                                    THREAD);
 686       result_oop = value();
 687       if (HAS_PENDING_EXCEPTION) {
 688         save_and_throw_exception(this_cp, index, tag, CHECK_NULL);
 689       }
 690       break;
 691     }
 692 
 693   case JVM_CONSTANT_MethodType:
 694     {
 695       Symbol*  signature = this_cp->method_type_signature_at(index);
 696       if (PrintMiscellaneous)
 697         tty->print_cr("resolve JVM_CONSTANT_MethodType [%d/%d] %s",
 698                       index, this_cp->method_type_index_at(index),
 699                       signature->as_C_string());
 700       KlassHandle klass(THREAD, this_cp->pool_holder());
 701       Handle value = SystemDictionary::find_method_handle_type(signature, klass, THREAD);
 702       result_oop = value();
 703       if (HAS_PENDING_EXCEPTION) {
 704         save_and_throw_exception(this_cp, index, tag, CHECK_NULL);
 705       }
 706       break;
 707     }
 708 
 709   case JVM_CONSTANT_Integer:
 710     assert(cache_index == _no_index_sentinel, "should not have been set");
 711     prim_value.i = this_cp->int_at(index);
 712     result_oop = java_lang_boxing_object::create(T_INT, &prim_value, CHECK_NULL);
 713     break;
 714 
 715   case JVM_CONSTANT_Float:
 716     assert(cache_index == _no_index_sentinel, "should not have been set");
 717     prim_value.f = this_cp->float_at(index);
 718     result_oop = java_lang_boxing_object::create(T_FLOAT, &prim_value, CHECK_NULL);
 719     break;
 720 
 721   case JVM_CONSTANT_Long:
 722     assert(cache_index == _no_index_sentinel, "should not have been set");
 723     prim_value.j = this_cp->long_at(index);
 724     result_oop = java_lang_boxing_object::create(T_LONG, &prim_value, CHECK_NULL);
 725     break;
 726 
 727   case JVM_CONSTANT_Double:
 728     assert(cache_index == _no_index_sentinel, "should not have been set");
 729     prim_value.d = this_cp->double_at(index);
 730     result_oop = java_lang_boxing_object::create(T_DOUBLE, &prim_value, CHECK_NULL);
 731     break;
 732 
 733   default:
 734     DEBUG_ONLY( tty->print_cr("*** %p: tag at CP[%d/%d] = %d",
 735                               this_cp(), index, cache_index, tag.value()));
 736     assert(false, "unexpected constant tag");
 737     break;
 738   }
 739 
 740   if (cache_index >= 0) {
 741     // Benign race condition:  resolved_references may already be filled in.
 742     // The important thing here is that all threads pick up the same result.
 743     // It doesn't matter which racing thread wins, as long as only one
 744     // result is used by all threads, and all future queries.
 745     oop old_result = this_cp->resolved_references()->atomic_compare_exchange_oop(cache_index, result_oop, NULL);
 746     if (old_result == NULL) {
 747       return result_oop;  // was installed
 748     } else {
 749       // Return the winning thread's result.  This can be different than
 750       // the result here for MethodHandles.
 751       return old_result;
 752     }
 753   } else {
 754     return result_oop;
 755   }
 756 }
 757 
 758 oop ConstantPool::uncached_string_at(int which, TRAPS) {
 759   Symbol* sym = unresolved_string_at(which);
 760   oop str = StringTable::intern(sym, CHECK_(NULL));
 761   assert(java_lang_String::is_instance(str), "must be string");
 762   return str;
 763 }
 764 
 765 
 766 oop ConstantPool::resolve_bootstrap_specifier_at_impl(const constantPoolHandle& this_cp, int index, TRAPS) {
 767   assert(this_cp->tag_at(index).is_invoke_dynamic(), "Corrupted constant pool");
 768 
 769   Handle bsm;
 770   int argc;
 771   {
 772     // JVM_CONSTANT_InvokeDynamic is an ordered pair of [bootm, name&type], plus optional arguments
 773     // The bootm, being a JVM_CONSTANT_MethodHandle, has its own cache entry.
 774     // It is accompanied by the optional arguments.
 775     int bsm_index = this_cp->invoke_dynamic_bootstrap_method_ref_index_at(index);
 776     oop bsm_oop = this_cp->resolve_possibly_cached_constant_at(bsm_index, CHECK_NULL);
 777     if (!java_lang_invoke_MethodHandle::is_instance(bsm_oop)) {
 778       THROW_MSG_NULL(vmSymbols::java_lang_LinkageError(), "BSM not an MethodHandle");
 779     }
 780 
 781     // Extract the optional static arguments.
 782     argc = this_cp->invoke_dynamic_argument_count_at(index);
 783     if (argc == 0)  return bsm_oop;
 784 
 785     bsm = Handle(THREAD, bsm_oop);
 786   }
 787 
 788   objArrayHandle info;
 789   {
 790     objArrayOop info_oop = oopFactory::new_objArray(SystemDictionary::Object_klass(), 1+argc, CHECK_NULL);
 791     info = objArrayHandle(THREAD, info_oop);
 792   }
 793 
 794   info->obj_at_put(0, bsm());
 795   for (int i = 0; i < argc; i++) {
 796     int arg_index = this_cp->invoke_dynamic_argument_index_at(index, i);
 797     oop arg_oop = this_cp->resolve_possibly_cached_constant_at(arg_index, CHECK_NULL);
 798     info->obj_at_put(1+i, arg_oop);
 799   }
 800 
 801   return info();
 802 }
 803 
 804 oop ConstantPool::string_at_impl(const constantPoolHandle& this_cp, int which, int obj_index, TRAPS) {
 805   // If the string has already been interned, this entry will be non-null
 806   oop str = this_cp->resolved_references()->obj_at(obj_index);
 807   if (str != NULL) return str;
 808   Symbol* sym = this_cp->unresolved_string_at(which);
 809   str = StringTable::intern(sym, CHECK_(NULL));
 810   this_cp->string_at_put(which, obj_index, str);
 811   assert(java_lang_String::is_instance(str), "must be string");
 812   return str;
 813 }
 814 
 815 
 816 bool ConstantPool::klass_name_at_matches(instanceKlassHandle k,
 817                                                 int which) {
 818   // Names are interned, so we can compare Symbol*s directly
 819   Symbol* cp_name = klass_name_at(which);
 820   return (cp_name == k->name());
 821 }
 822 
 823 
 824 // Iterate over symbols and decrement ones which are Symbol*s
 825 // This is done during GC.
 826 // Only decrement the UTF8 symbols. Unresolved classes and strings point to
 827 // these symbols but didn't increment the reference count.
 828 void ConstantPool::unreference_symbols() {
 829   for (int index = 1; index < length(); index++) { // Index 0 is unused
 830     constantTag tag = tag_at(index);
 831     if (tag.is_symbol()) {
 832       symbol_at(index)->decrement_refcount();
 833     }
 834   }
 835 }
 836 
 837 
 838 // Compare this constant pool's entry at index1 to the constant pool
 839 // cp2's entry at index2.
 840 bool ConstantPool::compare_entry_to(int index1, const constantPoolHandle& cp2,
 841        int index2, TRAPS) {
 842 
 843   // The error tags are equivalent to non-error tags when comparing
 844   jbyte t1 = tag_at(index1).non_error_value();
 845   jbyte t2 = cp2->tag_at(index2).non_error_value();
 846 
 847   if (t1 != t2) {
 848     // Not the same entry type so there is nothing else to check. Note
 849     // that this style of checking will consider resolved/unresolved
 850     // class pairs as different.
 851     // From the ConstantPool* API point of view, this is correct
 852     // behavior. See VM_RedefineClasses::merge_constant_pools() to see how this
 853     // plays out in the context of ConstantPool* merging.
 854     return false;
 855   }
 856 
 857   switch (t1) {
 858   case JVM_CONSTANT_Class:
 859   {
 860     Klass* k1 = klass_at(index1, CHECK_false);
 861     Klass* k2 = cp2->klass_at(index2, CHECK_false);
 862     if (k1 == k2) {
 863       return true;
 864     }
 865   } break;
 866 
 867   case JVM_CONSTANT_ClassIndex:
 868   {
 869     int recur1 = klass_index_at(index1);
 870     int recur2 = cp2->klass_index_at(index2);
 871     bool match = compare_entry_to(recur1, cp2, recur2, CHECK_false);
 872     if (match) {
 873       return true;
 874     }
 875   } break;
 876 
 877   case JVM_CONSTANT_Double:
 878   {
 879     jdouble d1 = double_at(index1);
 880     jdouble d2 = cp2->double_at(index2);
 881     if (d1 == d2) {
 882       return true;
 883     }
 884   } break;
 885 
 886   case JVM_CONSTANT_Fieldref:
 887   case JVM_CONSTANT_InterfaceMethodref:
 888   case JVM_CONSTANT_Methodref:
 889   {
 890     int recur1 = uncached_klass_ref_index_at(index1);
 891     int recur2 = cp2->uncached_klass_ref_index_at(index2);
 892     bool match = compare_entry_to(recur1, cp2, recur2, CHECK_false);
 893     if (match) {
 894       recur1 = uncached_name_and_type_ref_index_at(index1);
 895       recur2 = cp2->uncached_name_and_type_ref_index_at(index2);
 896       match = compare_entry_to(recur1, cp2, recur2, CHECK_false);
 897       if (match) {
 898         return true;
 899       }
 900     }
 901   } break;
 902 
 903   case JVM_CONSTANT_Float:
 904   {
 905     jfloat f1 = float_at(index1);
 906     jfloat f2 = cp2->float_at(index2);
 907     if (f1 == f2) {
 908       return true;
 909     }
 910   } break;
 911 
 912   case JVM_CONSTANT_Integer:
 913   {
 914     jint i1 = int_at(index1);
 915     jint i2 = cp2->int_at(index2);
 916     if (i1 == i2) {
 917       return true;
 918     }
 919   } break;
 920 
 921   case JVM_CONSTANT_Long:
 922   {
 923     jlong l1 = long_at(index1);
 924     jlong l2 = cp2->long_at(index2);
 925     if (l1 == l2) {
 926       return true;
 927     }
 928   } break;
 929 
 930   case JVM_CONSTANT_NameAndType:
 931   {
 932     int recur1 = name_ref_index_at(index1);
 933     int recur2 = cp2->name_ref_index_at(index2);
 934     bool match = compare_entry_to(recur1, cp2, recur2, CHECK_false);
 935     if (match) {
 936       recur1 = signature_ref_index_at(index1);
 937       recur2 = cp2->signature_ref_index_at(index2);
 938       match = compare_entry_to(recur1, cp2, recur2, CHECK_false);
 939       if (match) {
 940         return true;
 941       }
 942     }
 943   } break;
 944 
 945   case JVM_CONSTANT_StringIndex:
 946   {
 947     int recur1 = string_index_at(index1);
 948     int recur2 = cp2->string_index_at(index2);
 949     bool match = compare_entry_to(recur1, cp2, recur2, CHECK_false);
 950     if (match) {
 951       return true;
 952     }
 953   } break;
 954 
 955   case JVM_CONSTANT_UnresolvedClass:
 956   {
 957     Symbol* k1 = klass_name_at(index1);
 958     Symbol* k2 = cp2->klass_name_at(index2);
 959     if (k1 == k2) {
 960       return true;
 961     }
 962   } break;
 963 
 964   case JVM_CONSTANT_MethodType:
 965   {
 966     int k1 = method_type_index_at_error_ok(index1);
 967     int k2 = cp2->method_type_index_at_error_ok(index2);
 968     bool match = compare_entry_to(k1, cp2, k2, CHECK_false);
 969     if (match) {
 970       return true;
 971     }
 972   } break;
 973 
 974   case JVM_CONSTANT_MethodHandle:
 975   {
 976     int k1 = method_handle_ref_kind_at_error_ok(index1);
 977     int k2 = cp2->method_handle_ref_kind_at_error_ok(index2);
 978     if (k1 == k2) {
 979       int i1 = method_handle_index_at_error_ok(index1);
 980       int i2 = cp2->method_handle_index_at_error_ok(index2);
 981       bool match = compare_entry_to(i1, cp2, i2, CHECK_false);
 982       if (match) {
 983         return true;
 984       }
 985     }
 986   } break;
 987 
 988   case JVM_CONSTANT_InvokeDynamic:
 989   {
 990     int k1 = invoke_dynamic_name_and_type_ref_index_at(index1);
 991     int k2 = cp2->invoke_dynamic_name_and_type_ref_index_at(index2);
 992     int i1 = invoke_dynamic_bootstrap_specifier_index(index1);
 993     int i2 = cp2->invoke_dynamic_bootstrap_specifier_index(index2);
 994     // separate statements and variables because CHECK_false is used
 995     bool match_entry = compare_entry_to(k1, cp2, k2, CHECK_false);
 996     bool match_operand = compare_operand_to(i1, cp2, i2, CHECK_false);
 997     return (match_entry && match_operand);
 998   } break;
 999 
1000   case JVM_CONSTANT_String:
1001   {
1002     Symbol* s1 = unresolved_string_at(index1);
1003     Symbol* s2 = cp2->unresolved_string_at(index2);
1004     if (s1 == s2) {
1005       return true;
1006     }
1007   } break;
1008 
1009   case JVM_CONSTANT_Utf8:
1010   {
1011     Symbol* s1 = symbol_at(index1);
1012     Symbol* s2 = cp2->symbol_at(index2);
1013     if (s1 == s2) {
1014       return true;
1015     }
1016   } break;
1017 
1018   // Invalid is used as the tag for the second constant pool entry
1019   // occupied by JVM_CONSTANT_Double or JVM_CONSTANT_Long. It should
1020   // not be seen by itself.
1021   case JVM_CONSTANT_Invalid: // fall through
1022 
1023   default:
1024     ShouldNotReachHere();
1025     break;
1026   }
1027 
1028   return false;
1029 } // end compare_entry_to()
1030 
1031 
1032 // Resize the operands array with delta_len and delta_size.
1033 // Used in RedefineClasses for CP merge.
1034 void ConstantPool::resize_operands(int delta_len, int delta_size, TRAPS) {
1035   int old_len  = operand_array_length(operands());
1036   int new_len  = old_len + delta_len;
1037   int min_len  = (delta_len > 0) ? old_len : new_len;
1038 
1039   int old_size = operands()->length();
1040   int new_size = old_size + delta_size;
1041   int min_size = (delta_size > 0) ? old_size : new_size;
1042 
1043   ClassLoaderData* loader_data = pool_holder()->class_loader_data();
1044   Array<u2>* new_ops = MetadataFactory::new_array<u2>(loader_data, new_size, CHECK);
1045 
1046   // Set index in the resized array for existing elements only
1047   for (int idx = 0; idx < min_len; idx++) {
1048     int offset = operand_offset_at(idx);                       // offset in original array
1049     operand_offset_at_put(new_ops, idx, offset + 2*delta_len); // offset in resized array
1050   }
1051   // Copy the bootstrap specifiers only
1052   Copy::conjoint_memory_atomic(operands()->adr_at(2*old_len),
1053                                new_ops->adr_at(2*new_len),
1054                                (min_size - 2*min_len) * sizeof(u2));
1055   // Explicitly deallocate old operands array.
1056   // Note, it is not needed for 7u backport.
1057   if ( operands() != NULL) { // the safety check
1058     MetadataFactory::free_array<u2>(loader_data, operands());
1059   }
1060   set_operands(new_ops);
1061 } // end resize_operands()
1062 
1063 
1064 // Extend the operands array with the length and size of the ext_cp operands.
1065 // Used in RedefineClasses for CP merge.
1066 void ConstantPool::extend_operands(const constantPoolHandle& ext_cp, TRAPS) {
1067   int delta_len = operand_array_length(ext_cp->operands());
1068   if (delta_len == 0) {
1069     return; // nothing to do
1070   }
1071   int delta_size = ext_cp->operands()->length();
1072 
1073   assert(delta_len  > 0 && delta_size > 0, "extended operands array must be bigger");
1074 
1075   if (operand_array_length(operands()) == 0) {
1076     ClassLoaderData* loader_data = pool_holder()->class_loader_data();
1077     Array<u2>* new_ops = MetadataFactory::new_array<u2>(loader_data, delta_size, CHECK);
1078     // The first element index defines the offset of second part
1079     operand_offset_at_put(new_ops, 0, 2*delta_len); // offset in new array
1080     set_operands(new_ops);
1081   } else {
1082     resize_operands(delta_len, delta_size, CHECK);
1083   }
1084 
1085 } // end extend_operands()
1086 
1087 
1088 // Shrink the operands array to a smaller array with new_len length.
1089 // Used in RedefineClasses for CP merge.
1090 void ConstantPool::shrink_operands(int new_len, TRAPS) {
1091   int old_len = operand_array_length(operands());
1092   if (new_len == old_len) {
1093     return; // nothing to do
1094   }
1095   assert(new_len < old_len, "shrunken operands array must be smaller");
1096 
1097   int free_base  = operand_next_offset_at(new_len - 1);
1098   int delta_len  = new_len - old_len;
1099   int delta_size = 2*delta_len + free_base - operands()->length();
1100 
1101   resize_operands(delta_len, delta_size, CHECK);
1102 
1103 } // end shrink_operands()
1104 
1105 
1106 void ConstantPool::copy_operands(const constantPoolHandle& from_cp,
1107                                  const constantPoolHandle& to_cp,
1108                                  TRAPS) {
1109 
1110   int from_oplen = operand_array_length(from_cp->operands());
1111   int old_oplen  = operand_array_length(to_cp->operands());
1112   if (from_oplen != 0) {
1113     ClassLoaderData* loader_data = to_cp->pool_holder()->class_loader_data();
1114     // append my operands to the target's operands array
1115     if (old_oplen == 0) {
1116       // Can't just reuse from_cp's operand list because of deallocation issues
1117       int len = from_cp->operands()->length();
1118       Array<u2>* new_ops = MetadataFactory::new_array<u2>(loader_data, len, CHECK);
1119       Copy::conjoint_memory_atomic(
1120           from_cp->operands()->adr_at(0), new_ops->adr_at(0), len * sizeof(u2));
1121       to_cp->set_operands(new_ops);
1122     } else {
1123       int old_len  = to_cp->operands()->length();
1124       int from_len = from_cp->operands()->length();
1125       int old_off  = old_oplen * sizeof(u2);
1126       int from_off = from_oplen * sizeof(u2);
1127       // Use the metaspace for the destination constant pool
1128       Array<u2>* new_operands = MetadataFactory::new_array<u2>(loader_data, old_len + from_len, CHECK);
1129       int fillp = 0, len = 0;
1130       // first part of dest
1131       Copy::conjoint_memory_atomic(to_cp->operands()->adr_at(0),
1132                                    new_operands->adr_at(fillp),
1133                                    (len = old_off) * sizeof(u2));
1134       fillp += len;
1135       // first part of src
1136       Copy::conjoint_memory_atomic(from_cp->operands()->adr_at(0),
1137                                    new_operands->adr_at(fillp),
1138                                    (len = from_off) * sizeof(u2));
1139       fillp += len;
1140       // second part of dest
1141       Copy::conjoint_memory_atomic(to_cp->operands()->adr_at(old_off),
1142                                    new_operands->adr_at(fillp),
1143                                    (len = old_len - old_off) * sizeof(u2));
1144       fillp += len;
1145       // second part of src
1146       Copy::conjoint_memory_atomic(from_cp->operands()->adr_at(from_off),
1147                                    new_operands->adr_at(fillp),
1148                                    (len = from_len - from_off) * sizeof(u2));
1149       fillp += len;
1150       assert(fillp == new_operands->length(), "");
1151 
1152       // Adjust indexes in the first part of the copied operands array.
1153       for (int j = 0; j < from_oplen; j++) {
1154         int offset = operand_offset_at(new_operands, old_oplen + j);
1155         assert(offset == operand_offset_at(from_cp->operands(), j), "correct copy");
1156         offset += old_len;  // every new tuple is preceded by old_len extra u2's
1157         operand_offset_at_put(new_operands, old_oplen + j, offset);
1158       }
1159 
1160       // replace target operands array with combined array
1161       to_cp->set_operands(new_operands);
1162     }
1163   }
1164 } // end copy_operands()
1165 
1166 
1167 // Copy this constant pool's entries at start_i to end_i (inclusive)
1168 // to the constant pool to_cp's entries starting at to_i. A total of
1169 // (end_i - start_i) + 1 entries are copied.
1170 void ConstantPool::copy_cp_to_impl(const constantPoolHandle& from_cp, int start_i, int end_i,
1171        const constantPoolHandle& to_cp, int to_i, TRAPS) {
1172 
1173 
1174   int dest_i = to_i;  // leave original alone for debug purposes
1175 
1176   for (int src_i = start_i; src_i <= end_i; /* see loop bottom */ ) {
1177     copy_entry_to(from_cp, src_i, to_cp, dest_i, CHECK);
1178 
1179     switch (from_cp->tag_at(src_i).value()) {
1180     case JVM_CONSTANT_Double:
1181     case JVM_CONSTANT_Long:
1182       // double and long take two constant pool entries
1183       src_i += 2;
1184       dest_i += 2;
1185       break;
1186 
1187     default:
1188       // all others take one constant pool entry
1189       src_i++;
1190       dest_i++;
1191       break;
1192     }
1193   }
1194   copy_operands(from_cp, to_cp, CHECK);
1195 
1196 } // end copy_cp_to_impl()
1197 
1198 
1199 // Copy this constant pool's entry at from_i to the constant pool
1200 // to_cp's entry at to_i.
1201 void ConstantPool::copy_entry_to(const constantPoolHandle& from_cp, int from_i,
1202                                         const constantPoolHandle& to_cp, int to_i,
1203                                         TRAPS) {
1204 
1205   int tag = from_cp->tag_at(from_i).value();
1206   switch (tag) {
1207   case JVM_CONSTANT_Class:
1208   {
1209     Klass* k = from_cp->klass_at(from_i, CHECK);
1210     to_cp->klass_at_put(to_i, k);
1211   } break;
1212 
1213   case JVM_CONSTANT_ClassIndex:
1214   {
1215     jint ki = from_cp->klass_index_at(from_i);
1216     to_cp->klass_index_at_put(to_i, ki);
1217   } break;
1218 
1219   case JVM_CONSTANT_Double:
1220   {
1221     jdouble d = from_cp->double_at(from_i);
1222     to_cp->double_at_put(to_i, d);
1223     // double takes two constant pool entries so init second entry's tag
1224     to_cp->tag_at_put(to_i + 1, JVM_CONSTANT_Invalid);
1225   } break;
1226 
1227   case JVM_CONSTANT_Fieldref:
1228   {
1229     int class_index = from_cp->uncached_klass_ref_index_at(from_i);
1230     int name_and_type_index = from_cp->uncached_name_and_type_ref_index_at(from_i);
1231     to_cp->field_at_put(to_i, class_index, name_and_type_index);
1232   } break;
1233 
1234   case JVM_CONSTANT_Float:
1235   {
1236     jfloat f = from_cp->float_at(from_i);
1237     to_cp->float_at_put(to_i, f);
1238   } break;
1239 
1240   case JVM_CONSTANT_Integer:
1241   {
1242     jint i = from_cp->int_at(from_i);
1243     to_cp->int_at_put(to_i, i);
1244   } break;
1245 
1246   case JVM_CONSTANT_InterfaceMethodref:
1247   {
1248     int class_index = from_cp->uncached_klass_ref_index_at(from_i);
1249     int name_and_type_index = from_cp->uncached_name_and_type_ref_index_at(from_i);
1250     to_cp->interface_method_at_put(to_i, class_index, name_and_type_index);
1251   } break;
1252 
1253   case JVM_CONSTANT_Long:
1254   {
1255     jlong l = from_cp->long_at(from_i);
1256     to_cp->long_at_put(to_i, l);
1257     // long takes two constant pool entries so init second entry's tag
1258     to_cp->tag_at_put(to_i + 1, JVM_CONSTANT_Invalid);
1259   } break;
1260 
1261   case JVM_CONSTANT_Methodref:
1262   {
1263     int class_index = from_cp->uncached_klass_ref_index_at(from_i);
1264     int name_and_type_index = from_cp->uncached_name_and_type_ref_index_at(from_i);
1265     to_cp->method_at_put(to_i, class_index, name_and_type_index);
1266   } break;
1267 
1268   case JVM_CONSTANT_NameAndType:
1269   {
1270     int name_ref_index = from_cp->name_ref_index_at(from_i);
1271     int signature_ref_index = from_cp->signature_ref_index_at(from_i);
1272     to_cp->name_and_type_at_put(to_i, name_ref_index, signature_ref_index);
1273   } break;
1274 
1275   case JVM_CONSTANT_StringIndex:
1276   {
1277     jint si = from_cp->string_index_at(from_i);
1278     to_cp->string_index_at_put(to_i, si);
1279   } break;
1280 
1281   case JVM_CONSTANT_UnresolvedClass:
1282   case JVM_CONSTANT_UnresolvedClassInError:
1283   {
1284     // Can be resolved after checking tag, so check the slot first.
1285     CPSlot entry = from_cp->slot_at(from_i);
1286     if (entry.is_resolved()) {
1287       assert(entry.get_klass()->is_klass(), "must be");
1288       // Already resolved
1289       to_cp->klass_at_put(to_i, entry.get_klass());
1290     } else {
1291       to_cp->unresolved_klass_at_put(to_i, entry.get_symbol());
1292     }
1293   } break;
1294 
1295   case JVM_CONSTANT_String:
1296   {
1297     Symbol* s = from_cp->unresolved_string_at(from_i);
1298     to_cp->unresolved_string_at_put(to_i, s);
1299   } break;
1300 
1301   case JVM_CONSTANT_Utf8:
1302   {
1303     Symbol* s = from_cp->symbol_at(from_i);
1304     // Need to increase refcount, the old one will be thrown away and deferenced
1305     s->increment_refcount();
1306     to_cp->symbol_at_put(to_i, s);
1307   } break;
1308 
1309   case JVM_CONSTANT_MethodType:
1310   case JVM_CONSTANT_MethodTypeInError:
1311   {
1312     jint k = from_cp->method_type_index_at_error_ok(from_i);
1313     to_cp->method_type_index_at_put(to_i, k);
1314   } break;
1315 
1316   case JVM_CONSTANT_MethodHandle:
1317   case JVM_CONSTANT_MethodHandleInError:
1318   {
1319     int k1 = from_cp->method_handle_ref_kind_at_error_ok(from_i);
1320     int k2 = from_cp->method_handle_index_at_error_ok(from_i);
1321     to_cp->method_handle_index_at_put(to_i, k1, k2);
1322   } break;
1323 
1324   case JVM_CONSTANT_InvokeDynamic:
1325   {
1326     int k1 = from_cp->invoke_dynamic_bootstrap_specifier_index(from_i);
1327     int k2 = from_cp->invoke_dynamic_name_and_type_ref_index_at(from_i);
1328     k1 += operand_array_length(to_cp->operands());  // to_cp might already have operands
1329     to_cp->invoke_dynamic_at_put(to_i, k1, k2);
1330   } break;
1331 
1332   // Invalid is used as the tag for the second constant pool entry
1333   // occupied by JVM_CONSTANT_Double or JVM_CONSTANT_Long. It should
1334   // not be seen by itself.
1335   case JVM_CONSTANT_Invalid: // fall through
1336 
1337   default:
1338   {
1339     ShouldNotReachHere();
1340   } break;
1341   }
1342 } // end copy_entry_to()
1343 
1344 
1345 // Search constant pool search_cp for an entry that matches this
1346 // constant pool's entry at pattern_i. Returns the index of a
1347 // matching entry or zero (0) if there is no matching entry.
1348 int ConstantPool::find_matching_entry(int pattern_i,
1349       const constantPoolHandle& search_cp, TRAPS) {
1350 
1351   // index zero (0) is not used
1352   for (int i = 1; i < search_cp->length(); i++) {
1353     bool found = compare_entry_to(pattern_i, search_cp, i, CHECK_0);
1354     if (found) {
1355       return i;
1356     }
1357   }
1358 
1359   return 0;  // entry not found; return unused index zero (0)
1360 } // end find_matching_entry()
1361 
1362 
1363 // Compare this constant pool's bootstrap specifier at idx1 to the constant pool
1364 // cp2's bootstrap specifier at idx2.
1365 bool ConstantPool::compare_operand_to(int idx1, const constantPoolHandle& cp2, int idx2, TRAPS) {
1366   int k1 = operand_bootstrap_method_ref_index_at(idx1);
1367   int k2 = cp2->operand_bootstrap_method_ref_index_at(idx2);
1368   bool match = compare_entry_to(k1, cp2, k2, CHECK_false);
1369 
1370   if (!match) {
1371     return false;
1372   }
1373   int argc = operand_argument_count_at(idx1);
1374   if (argc == cp2->operand_argument_count_at(idx2)) {
1375     for (int j = 0; j < argc; j++) {
1376       k1 = operand_argument_index_at(idx1, j);
1377       k2 = cp2->operand_argument_index_at(idx2, j);
1378       match = compare_entry_to(k1, cp2, k2, CHECK_false);
1379       if (!match) {
1380         return false;
1381       }
1382     }
1383     return true;           // got through loop; all elements equal
1384   }
1385   return false;
1386 } // end compare_operand_to()
1387 
1388 // Search constant pool search_cp for a bootstrap specifier that matches
1389 // this constant pool's bootstrap specifier at pattern_i index.
1390 // Return the index of a matching bootstrap specifier or (-1) if there is no match.
1391 int ConstantPool::find_matching_operand(int pattern_i,
1392                     const constantPoolHandle& search_cp, int search_len, TRAPS) {
1393   for (int i = 0; i < search_len; i++) {
1394     bool found = compare_operand_to(pattern_i, search_cp, i, CHECK_(-1));
1395     if (found) {
1396       return i;
1397     }
1398   }
1399   return -1;  // bootstrap specifier not found; return unused index (-1)
1400 } // end find_matching_operand()
1401 
1402 
1403 #ifndef PRODUCT
1404 
1405 const char* ConstantPool::printable_name_at(int which) {
1406 
1407   constantTag tag = tag_at(which);
1408 
1409   if (tag.is_string()) {
1410     return string_at_noresolve(which);
1411   } else if (tag.is_klass() || tag.is_unresolved_klass()) {
1412     return klass_name_at(which)->as_C_string();
1413   } else if (tag.is_symbol()) {
1414     return symbol_at(which)->as_C_string();
1415   }
1416   return "";
1417 }
1418 
1419 #endif // PRODUCT
1420 
1421 
1422 // JVMTI GetConstantPool support
1423 
1424 // For debugging of constant pool
1425 const bool debug_cpool = false;
1426 
1427 #define DBG(code) do { if (debug_cpool) { (code); } } while(0)
1428 
1429 static void print_cpool_bytes(jint cnt, u1 *bytes) {
1430   const char* WARN_MSG = "Must not be such entry!";
1431   jint size = 0;
1432   u2   idx1, idx2;
1433 
1434   for (jint idx = 1; idx < cnt; idx++) {
1435     jint ent_size = 0;
1436     u1   tag  = *bytes++;
1437     size++;                       // count tag
1438 
1439     printf("const #%03d, tag: %02d ", idx, tag);
1440     switch(tag) {
1441       case JVM_CONSTANT_Invalid: {
1442         printf("Invalid");
1443         break;
1444       }
1445       case JVM_CONSTANT_Unicode: {
1446         printf("Unicode      %s", WARN_MSG);
1447         break;
1448       }
1449       case JVM_CONSTANT_Utf8: {
1450         u2 len = Bytes::get_Java_u2(bytes);
1451         char str[128];
1452         if (len > 127) {
1453            len = 127;
1454         }
1455         strncpy(str, (char *) (bytes+2), len);
1456         str[len] = '\0';
1457         printf("Utf8          \"%s\"", str);
1458         ent_size = 2 + len;
1459         break;
1460       }
1461       case JVM_CONSTANT_Integer: {
1462         u4 val = Bytes::get_Java_u4(bytes);
1463         printf("int          %d", *(int *) &val);
1464         ent_size = 4;
1465         break;
1466       }
1467       case JVM_CONSTANT_Float: {
1468         u4 val = Bytes::get_Java_u4(bytes);
1469         printf("float        %5.3ff", *(float *) &val);
1470         ent_size = 4;
1471         break;
1472       }
1473       case JVM_CONSTANT_Long: {
1474         u8 val = Bytes::get_Java_u8(bytes);
1475         printf("long         " INT64_FORMAT, (int64_t) *(jlong *) &val);
1476         ent_size = 8;
1477         idx++; // Long takes two cpool slots
1478         break;
1479       }
1480       case JVM_CONSTANT_Double: {
1481         u8 val = Bytes::get_Java_u8(bytes);
1482         printf("double       %5.3fd", *(jdouble *)&val);
1483         ent_size = 8;
1484         idx++; // Double takes two cpool slots
1485         break;
1486       }
1487       case JVM_CONSTANT_Class: {
1488         idx1 = Bytes::get_Java_u2(bytes);
1489         printf("class        #%03d", idx1);
1490         ent_size = 2;
1491         break;
1492       }
1493       case JVM_CONSTANT_String: {
1494         idx1 = Bytes::get_Java_u2(bytes);
1495         printf("String       #%03d", idx1);
1496         ent_size = 2;
1497         break;
1498       }
1499       case JVM_CONSTANT_Fieldref: {
1500         idx1 = Bytes::get_Java_u2(bytes);
1501         idx2 = Bytes::get_Java_u2(bytes+2);
1502         printf("Field        #%03d, #%03d", (int) idx1, (int) idx2);
1503         ent_size = 4;
1504         break;
1505       }
1506       case JVM_CONSTANT_Methodref: {
1507         idx1 = Bytes::get_Java_u2(bytes);
1508         idx2 = Bytes::get_Java_u2(bytes+2);
1509         printf("Method       #%03d, #%03d", idx1, idx2);
1510         ent_size = 4;
1511         break;
1512       }
1513       case JVM_CONSTANT_InterfaceMethodref: {
1514         idx1 = Bytes::get_Java_u2(bytes);
1515         idx2 = Bytes::get_Java_u2(bytes+2);
1516         printf("InterfMethod #%03d, #%03d", idx1, idx2);
1517         ent_size = 4;
1518         break;
1519       }
1520       case JVM_CONSTANT_NameAndType: {
1521         idx1 = Bytes::get_Java_u2(bytes);
1522         idx2 = Bytes::get_Java_u2(bytes+2);
1523         printf("NameAndType  #%03d, #%03d", idx1, idx2);
1524         ent_size = 4;
1525         break;
1526       }
1527       case JVM_CONSTANT_ClassIndex: {
1528         printf("ClassIndex  %s", WARN_MSG);
1529         break;
1530       }
1531       case JVM_CONSTANT_UnresolvedClass: {
1532         printf("UnresolvedClass: %s", WARN_MSG);
1533         break;
1534       }
1535       case JVM_CONSTANT_UnresolvedClassInError: {
1536         printf("UnresolvedClassInErr: %s", WARN_MSG);
1537         break;
1538       }
1539       case JVM_CONSTANT_StringIndex: {
1540         printf("StringIndex: %s", WARN_MSG);
1541         break;
1542       }
1543     }
1544     printf(";\n");
1545     bytes += ent_size;
1546     size  += ent_size;
1547   }
1548   printf("Cpool size: %d\n", size);
1549   fflush(0);
1550   return;
1551 } /* end print_cpool_bytes */
1552 
1553 
1554 // Returns size of constant pool entry.
1555 jint ConstantPool::cpool_entry_size(jint idx) {
1556   switch(tag_at(idx).value()) {
1557     case JVM_CONSTANT_Invalid:
1558     case JVM_CONSTANT_Unicode:
1559       return 1;
1560 
1561     case JVM_CONSTANT_Utf8:
1562       return 3 + symbol_at(idx)->utf8_length();
1563 
1564     case JVM_CONSTANT_Class:
1565     case JVM_CONSTANT_String:
1566     case JVM_CONSTANT_ClassIndex:
1567     case JVM_CONSTANT_UnresolvedClass:
1568     case JVM_CONSTANT_UnresolvedClassInError:
1569     case JVM_CONSTANT_StringIndex:
1570     case JVM_CONSTANT_MethodType:
1571     case JVM_CONSTANT_MethodTypeInError:
1572       return 3;
1573 
1574     case JVM_CONSTANT_MethodHandle:
1575     case JVM_CONSTANT_MethodHandleInError:
1576       return 4; //tag, ref_kind, ref_index
1577 
1578     case JVM_CONSTANT_Integer:
1579     case JVM_CONSTANT_Float:
1580     case JVM_CONSTANT_Fieldref:
1581     case JVM_CONSTANT_Methodref:
1582     case JVM_CONSTANT_InterfaceMethodref:
1583     case JVM_CONSTANT_NameAndType:
1584       return 5;
1585 
1586     case JVM_CONSTANT_InvokeDynamic:
1587       // u1 tag, u2 bsm, u2 nt
1588       return 5;
1589 
1590     case JVM_CONSTANT_Long:
1591     case JVM_CONSTANT_Double:
1592       return 9;
1593   }
1594   assert(false, "cpool_entry_size: Invalid constant pool entry tag");
1595   return 1;
1596 } /* end cpool_entry_size */
1597 
1598 
1599 // SymbolHashMap is used to find a constant pool index from a string.
1600 // This function fills in SymbolHashMaps, one for utf8s and one for
1601 // class names, returns size of the cpool raw bytes.
1602 jint ConstantPool::hash_entries_to(SymbolHashMap *symmap,
1603                                           SymbolHashMap *classmap) {
1604   jint size = 0;
1605 
1606   for (u2 idx = 1; idx < length(); idx++) {
1607     u2 tag = tag_at(idx).value();
1608     size += cpool_entry_size(idx);
1609 
1610     switch(tag) {
1611       case JVM_CONSTANT_Utf8: {
1612         Symbol* sym = symbol_at(idx);
1613         symmap->add_entry(sym, idx);
1614         DBG(printf("adding symbol entry %s = %d\n", sym->as_utf8(), idx));
1615         break;
1616       }
1617       case JVM_CONSTANT_Class:
1618       case JVM_CONSTANT_UnresolvedClass:
1619       case JVM_CONSTANT_UnresolvedClassInError: {
1620         Symbol* sym = klass_name_at(idx);
1621         classmap->add_entry(sym, idx);
1622         DBG(printf("adding class entry %s = %d\n", sym->as_utf8(), idx));
1623         break;
1624       }
1625       case JVM_CONSTANT_Long:
1626       case JVM_CONSTANT_Double: {
1627         idx++; // Both Long and Double take two cpool slots
1628         break;
1629       }
1630     }
1631   }
1632   return size;
1633 } /* end hash_utf8_entries_to */
1634 
1635 
1636 // Copy cpool bytes.
1637 // Returns:
1638 //    0, in case of OutOfMemoryError
1639 //   -1, in case of internal error
1640 //  > 0, count of the raw cpool bytes that have been copied
1641 int ConstantPool::copy_cpool_bytes(int cpool_size,
1642                                           SymbolHashMap* tbl,
1643                                           unsigned char *bytes) {
1644   u2   idx1, idx2;
1645   jint size  = 0;
1646   jint cnt   = length();
1647   unsigned char *start_bytes = bytes;
1648 
1649   for (jint idx = 1; idx < cnt; idx++) {
1650     u1   tag      = tag_at(idx).value();
1651     jint ent_size = cpool_entry_size(idx);
1652 
1653     assert(size + ent_size <= cpool_size, "Size mismatch");
1654 
1655     *bytes = tag;
1656     DBG(printf("#%03hd tag=%03hd, ", idx, tag));
1657     switch(tag) {
1658       case JVM_CONSTANT_Invalid: {
1659         DBG(printf("JVM_CONSTANT_Invalid"));
1660         break;
1661       }
1662       case JVM_CONSTANT_Unicode: {
1663         assert(false, "Wrong constant pool tag: JVM_CONSTANT_Unicode");
1664         DBG(printf("JVM_CONSTANT_Unicode"));
1665         break;
1666       }
1667       case JVM_CONSTANT_Utf8: {
1668         Symbol* sym = symbol_at(idx);
1669         char*     str = sym->as_utf8();
1670         // Warning! It's crashing on x86 with len = sym->utf8_length()
1671         int       len = (int) strlen(str);
1672         Bytes::put_Java_u2((address) (bytes+1), (u2) len);
1673         for (int i = 0; i < len; i++) {
1674             bytes[3+i] = (u1) str[i];
1675         }
1676         DBG(printf("JVM_CONSTANT_Utf8: %s ", str));
1677         break;
1678       }
1679       case JVM_CONSTANT_Integer: {
1680         jint val = int_at(idx);
1681         Bytes::put_Java_u4((address) (bytes+1), *(u4*)&val);
1682         break;
1683       }
1684       case JVM_CONSTANT_Float: {
1685         jfloat val = float_at(idx);
1686         Bytes::put_Java_u4((address) (bytes+1), *(u4*)&val);
1687         break;
1688       }
1689       case JVM_CONSTANT_Long: {
1690         jlong val = long_at(idx);
1691         Bytes::put_Java_u8((address) (bytes+1), *(u8*)&val);
1692         idx++;             // Long takes two cpool slots
1693         break;
1694       }
1695       case JVM_CONSTANT_Double: {
1696         jdouble val = double_at(idx);
1697         Bytes::put_Java_u8((address) (bytes+1), *(u8*)&val);
1698         idx++;             // Double takes two cpool slots
1699         break;
1700       }
1701       case JVM_CONSTANT_Class:
1702       case JVM_CONSTANT_UnresolvedClass:
1703       case JVM_CONSTANT_UnresolvedClassInError: {
1704         *bytes = JVM_CONSTANT_Class;
1705         Symbol* sym = klass_name_at(idx);
1706         idx1 = tbl->symbol_to_value(sym);
1707         assert(idx1 != 0, "Have not found a hashtable entry");
1708         Bytes::put_Java_u2((address) (bytes+1), idx1);
1709         DBG(printf("JVM_CONSTANT_Class: idx=#%03hd, %s", idx1, sym->as_utf8()));
1710         break;
1711       }
1712       case JVM_CONSTANT_String: {
1713         *bytes = JVM_CONSTANT_String;
1714         Symbol* sym = unresolved_string_at(idx);
1715         idx1 = tbl->symbol_to_value(sym);
1716         assert(idx1 != 0, "Have not found a hashtable entry");
1717         Bytes::put_Java_u2((address) (bytes+1), idx1);
1718         DBG(printf("JVM_CONSTANT_String: idx=#%03hd, %s", idx1, sym->as_utf8()));
1719         break;
1720       }
1721       case JVM_CONSTANT_Fieldref:
1722       case JVM_CONSTANT_Methodref:
1723       case JVM_CONSTANT_InterfaceMethodref: {
1724         idx1 = uncached_klass_ref_index_at(idx);
1725         idx2 = uncached_name_and_type_ref_index_at(idx);
1726         Bytes::put_Java_u2((address) (bytes+1), idx1);
1727         Bytes::put_Java_u2((address) (bytes+3), idx2);
1728         DBG(printf("JVM_CONSTANT_Methodref: %hd %hd", idx1, idx2));
1729         break;
1730       }
1731       case JVM_CONSTANT_NameAndType: {
1732         idx1 = name_ref_index_at(idx);
1733         idx2 = signature_ref_index_at(idx);
1734         Bytes::put_Java_u2((address) (bytes+1), idx1);
1735         Bytes::put_Java_u2((address) (bytes+3), idx2);
1736         DBG(printf("JVM_CONSTANT_NameAndType: %hd %hd", idx1, idx2));
1737         break;
1738       }
1739       case JVM_CONSTANT_ClassIndex: {
1740         *bytes = JVM_CONSTANT_Class;
1741         idx1 = klass_index_at(idx);
1742         Bytes::put_Java_u2((address) (bytes+1), idx1);
1743         DBG(printf("JVM_CONSTANT_ClassIndex: %hd", idx1));
1744         break;
1745       }
1746       case JVM_CONSTANT_StringIndex: {
1747         *bytes = JVM_CONSTANT_String;
1748         idx1 = string_index_at(idx);
1749         Bytes::put_Java_u2((address) (bytes+1), idx1);
1750         DBG(printf("JVM_CONSTANT_StringIndex: %hd", idx1));
1751         break;
1752       }
1753       case JVM_CONSTANT_MethodHandle:
1754       case JVM_CONSTANT_MethodHandleInError: {
1755         *bytes = JVM_CONSTANT_MethodHandle;
1756         int kind = method_handle_ref_kind_at_error_ok(idx);
1757         idx1 = method_handle_index_at_error_ok(idx);
1758         *(bytes+1) = (unsigned char) kind;
1759         Bytes::put_Java_u2((address) (bytes+2), idx1);
1760         DBG(printf("JVM_CONSTANT_MethodHandle: %d %hd", kind, idx1));
1761         break;
1762       }
1763       case JVM_CONSTANT_MethodType:
1764       case JVM_CONSTANT_MethodTypeInError: {
1765         *bytes = JVM_CONSTANT_MethodType;
1766         idx1 = method_type_index_at_error_ok(idx);
1767         Bytes::put_Java_u2((address) (bytes+1), idx1);
1768         DBG(printf("JVM_CONSTANT_MethodType: %hd", idx1));
1769         break;
1770       }
1771       case JVM_CONSTANT_InvokeDynamic: {
1772         *bytes = tag;
1773         idx1 = extract_low_short_from_int(*int_at_addr(idx));
1774         idx2 = extract_high_short_from_int(*int_at_addr(idx));
1775         assert(idx2 == invoke_dynamic_name_and_type_ref_index_at(idx), "correct half of u4");
1776         Bytes::put_Java_u2((address) (bytes+1), idx1);
1777         Bytes::put_Java_u2((address) (bytes+3), idx2);
1778         DBG(printf("JVM_CONSTANT_InvokeDynamic: %hd %hd", idx1, idx2));
1779         break;
1780       }
1781     }
1782     DBG(printf("\n"));
1783     bytes += ent_size;
1784     size  += ent_size;
1785   }
1786   assert(size == cpool_size, "Size mismatch");
1787 
1788   // Keep temorarily for debugging until it's stable.
1789   DBG(print_cpool_bytes(cnt, start_bytes));
1790   return (int)(bytes - start_bytes);
1791 } /* end copy_cpool_bytes */
1792 
1793 #undef DBG
1794 
1795 
1796 void ConstantPool::set_on_stack(const bool value) {
1797   if (value) {
1798     // Only record if it's not already set.
1799     if (!on_stack()) {
1800       _flags |= _on_stack;
1801       MetadataOnStackMark::record(this);
1802     }
1803   } else {
1804     // Clearing is done single-threadedly.
1805     _flags &= ~_on_stack;
1806   }
1807 }
1808 
1809 // JSR 292 support for patching constant pool oops after the class is linked and
1810 // the oop array for resolved references are created.
1811 // We can't do this during classfile parsing, which is how the other indexes are
1812 // patched.  The other patches are applied early for some error checking
1813 // so only defer the pseudo_strings.
1814 void ConstantPool::patch_resolved_references(GrowableArray<Handle>* cp_patches) {
1815   for (int index = 1; index < cp_patches->length(); index++) { // Index 0 is unused
1816     Handle patch = cp_patches->at(index);
1817     if (patch.not_null()) {
1818       assert (tag_at(index).is_string(), "should only be string left");
1819       // Patching a string means pre-resolving it.
1820       // The spelling in the constant pool is ignored.
1821       // The constant reference may be any object whatever.
1822       // If it is not a real interned string, the constant is referred
1823       // to as a "pseudo-string", and must be presented to the CP
1824       // explicitly, because it may require scavenging.
1825       int obj_index = cp_to_object_index(index);
1826       pseudo_string_at_put(index, obj_index, patch());
1827      DEBUG_ONLY(cp_patches->at_put(index, Handle());)
1828     }
1829   }
1830 #ifdef ASSERT
1831   // Ensure that all the patches have been used.
1832   for (int index = 0; index < cp_patches->length(); index++) {
1833     assert(cp_patches->at(index).is_null(),
1834            "Unused constant pool patch at %d in class file %s",
1835            index,
1836            pool_holder()->external_name());
1837   }
1838 #endif // ASSERT
1839 }
1840 
1841 #ifndef PRODUCT
1842 
1843 // CompileTheWorld support. Preload all classes loaded references in the passed in constantpool
1844 void ConstantPool::preload_and_initialize_all_classes(ConstantPool* obj, TRAPS) {
1845   guarantee(obj->is_constantPool(), "object must be constant pool");
1846   constantPoolHandle cp(THREAD, (ConstantPool*)obj);
1847   guarantee(cp->pool_holder() != NULL, "must be fully loaded");
1848 
1849   for (int i = 0; i< cp->length();  i++) {
1850     if (cp->tag_at(i).is_unresolved_klass()) {
1851       // This will force loading of the class
1852       Klass* klass = cp->klass_at(i, CHECK);
1853       if (klass->is_instance_klass()) {
1854         // Force initialization of class
1855         InstanceKlass::cast(klass)->initialize(CHECK);
1856       }
1857     }
1858   }
1859 }
1860 
1861 #endif
1862 
1863 
1864 // Printing
1865 
1866 void ConstantPool::print_on(outputStream* st) const {
1867   assert(is_constantPool(), "must be constantPool");
1868   st->print_cr("%s", internal_name());
1869   if (flags() != 0) {
1870     st->print(" - flags: 0x%x", flags());
1871     if (has_preresolution()) st->print(" has_preresolution");
1872     if (on_stack()) st->print(" on_stack");
1873     st->cr();
1874   }
1875   if (pool_holder() != NULL) {
1876     st->print_cr(" - holder: " INTPTR_FORMAT, p2i(pool_holder()));
1877   }
1878   st->print_cr(" - cache: " INTPTR_FORMAT, p2i(cache()));
1879   st->print_cr(" - resolved_references: " INTPTR_FORMAT, p2i(resolved_references()));
1880   st->print_cr(" - reference_map: " INTPTR_FORMAT, p2i(reference_map()));
1881 
1882   for (int index = 1; index < length(); index++) {      // Index 0 is unused
1883     ((ConstantPool*)this)->print_entry_on(index, st);
1884     switch (tag_at(index).value()) {
1885       case JVM_CONSTANT_Long :
1886       case JVM_CONSTANT_Double :
1887         index++;   // Skip entry following eigth-byte constant
1888     }
1889 
1890   }
1891   st->cr();
1892 }
1893 
1894 // Print one constant pool entry
1895 void ConstantPool::print_entry_on(const int index, outputStream* st) {
1896   EXCEPTION_MARK;
1897   st->print(" - %3d : ", index);
1898   tag_at(index).print_on(st);
1899   st->print(" : ");
1900   switch (tag_at(index).value()) {
1901     case JVM_CONSTANT_Class :
1902       { Klass* k = klass_at(index, CATCH);
1903         guarantee(k != NULL, "need klass");
1904         k->print_value_on(st);
1905         st->print(" {" PTR_FORMAT "}", p2i(k));
1906       }
1907       break;
1908     case JVM_CONSTANT_Fieldref :
1909     case JVM_CONSTANT_Methodref :
1910     case JVM_CONSTANT_InterfaceMethodref :
1911       st->print("klass_index=%d", uncached_klass_ref_index_at(index));
1912       st->print(" name_and_type_index=%d", uncached_name_and_type_ref_index_at(index));
1913       break;
1914     case JVM_CONSTANT_String :
1915       if (is_pseudo_string_at(index)) {
1916         oop anObj = pseudo_string_at(index);
1917         anObj->print_value_on(st);
1918         st->print(" {" PTR_FORMAT "}", p2i(anObj));
1919       } else {
1920         unresolved_string_at(index)->print_value_on(st);
1921       }
1922       break;
1923     case JVM_CONSTANT_Integer :
1924       st->print("%d", int_at(index));
1925       break;
1926     case JVM_CONSTANT_Float :
1927       st->print("%f", float_at(index));
1928       break;
1929     case JVM_CONSTANT_Long :
1930       st->print_jlong(long_at(index));
1931       break;
1932     case JVM_CONSTANT_Double :
1933       st->print("%lf", double_at(index));
1934       break;
1935     case JVM_CONSTANT_NameAndType :
1936       st->print("name_index=%d", name_ref_index_at(index));
1937       st->print(" signature_index=%d", signature_ref_index_at(index));
1938       break;
1939     case JVM_CONSTANT_Utf8 :
1940       symbol_at(index)->print_value_on(st);
1941       break;
1942     case JVM_CONSTANT_UnresolvedClass :               // fall-through
1943     case JVM_CONSTANT_UnresolvedClassInError: {
1944       CPSlot entry = slot_at(index);
1945       if (entry.is_resolved()) {
1946         entry.get_klass()->print_value_on(st);
1947       } else {
1948         entry.get_symbol()->print_value_on(st);
1949       }
1950       }
1951       break;
1952     case JVM_CONSTANT_MethodHandle :
1953     case JVM_CONSTANT_MethodHandleInError :
1954       st->print("ref_kind=%d", method_handle_ref_kind_at_error_ok(index));
1955       st->print(" ref_index=%d", method_handle_index_at_error_ok(index));
1956       break;
1957     case JVM_CONSTANT_MethodType :
1958     case JVM_CONSTANT_MethodTypeInError :
1959       st->print("signature_index=%d", method_type_index_at_error_ok(index));
1960       break;
1961     case JVM_CONSTANT_InvokeDynamic :
1962       {
1963         st->print("bootstrap_method_index=%d", invoke_dynamic_bootstrap_method_ref_index_at(index));
1964         st->print(" name_and_type_index=%d", invoke_dynamic_name_and_type_ref_index_at(index));
1965         int argc = invoke_dynamic_argument_count_at(index);
1966         if (argc > 0) {
1967           for (int arg_i = 0; arg_i < argc; arg_i++) {
1968             int arg = invoke_dynamic_argument_index_at(index, arg_i);
1969             st->print((arg_i == 0 ? " arguments={%d" : ", %d"), arg);
1970           }
1971           st->print("}");
1972         }
1973       }
1974       break;
1975     default:
1976       ShouldNotReachHere();
1977       break;
1978   }
1979   st->cr();
1980 }
1981 
1982 void ConstantPool::print_value_on(outputStream* st) const {
1983   assert(is_constantPool(), "must be constantPool");
1984   st->print("constant pool [%d]", length());
1985   if (has_preresolution()) st->print("/preresolution");
1986   if (operands() != NULL)  st->print("/operands[%d]", operands()->length());
1987   print_address_on(st);
1988   st->print(" for ");
1989   pool_holder()->print_value_on(st);
1990   if (pool_holder() != NULL) {
1991     bool extra = (pool_holder()->constants() != this);
1992     if (extra)  st->print(" (extra)");
1993   }
1994   if (cache() != NULL) {
1995     st->print(" cache=" PTR_FORMAT, p2i(cache()));
1996   }
1997 }
1998 
1999 #if INCLUDE_SERVICES
2000 // Size Statistics
2001 void ConstantPool::collect_statistics(KlassSizeStats *sz) const {
2002   sz->_cp_all_bytes += (sz->_cp_bytes          = sz->count(this));
2003   sz->_cp_all_bytes += (sz->_cp_tags_bytes     = sz->count_array(tags()));
2004   sz->_cp_all_bytes += (sz->_cp_cache_bytes    = sz->count(cache()));
2005   sz->_cp_all_bytes += (sz->_cp_operands_bytes = sz->count_array(operands()));
2006   sz->_cp_all_bytes += (sz->_cp_refmap_bytes   = sz->count_array(reference_map()));
2007 
2008   sz->_ro_bytes += sz->_cp_operands_bytes + sz->_cp_tags_bytes +
2009                    sz->_cp_refmap_bytes;
2010   sz->_rw_bytes += sz->_cp_bytes + sz->_cp_cache_bytes;
2011 }
2012 #endif // INCLUDE_SERVICES
2013 
2014 // Verification
2015 
2016 void ConstantPool::verify_on(outputStream* st) {
2017   guarantee(is_constantPool(), "object must be constant pool");
2018   for (int i = 0; i< length();  i++) {
2019     constantTag tag = tag_at(i);
2020     CPSlot entry = slot_at(i);
2021     if (tag.is_klass()) {
2022       if (entry.is_resolved()) {
2023         guarantee(entry.get_klass()->is_klass(),    "should be klass");
2024       }
2025     } else if (tag.is_unresolved_klass()) {
2026       if (entry.is_resolved()) {
2027         guarantee(entry.get_klass()->is_klass(),    "should be klass");
2028       }
2029     } else if (tag.is_symbol()) {
2030       guarantee(entry.get_symbol()->refcount() != 0, "should have nonzero reference count");
2031     } else if (tag.is_string()) {
2032       guarantee(entry.get_symbol()->refcount() != 0, "should have nonzero reference count");
2033     }
2034   }
2035   if (cache() != NULL) {
2036     // Note: cache() can be NULL before a class is completely setup or
2037     // in temporary constant pools used during constant pool merging
2038     guarantee(cache()->is_constantPoolCache(), "should be constant pool cache");
2039   }
2040   if (pool_holder() != NULL) {
2041     // Note: pool_holder() can be NULL in temporary constant pools
2042     // used during constant pool merging
2043     guarantee(pool_holder()->is_klass(),    "should be klass");
2044   }
2045 }
2046 
2047 
2048 void SymbolHashMap::add_entry(Symbol* sym, u2 value) {
2049   char *str = sym->as_utf8();
2050   unsigned int hash = compute_hash(str, sym->utf8_length());
2051   unsigned int index = hash % table_size();
2052 
2053   // check if already in map
2054   // we prefer the first entry since it is more likely to be what was used in
2055   // the class file
2056   for (SymbolHashMapEntry *en = bucket(index); en != NULL; en = en->next()) {
2057     assert(en->symbol() != NULL, "SymbolHashMapEntry symbol is NULL");
2058     if (en->hash() == hash && en->symbol() == sym) {
2059         return;  // already there
2060     }
2061   }
2062 
2063   SymbolHashMapEntry* entry = new SymbolHashMapEntry(hash, sym, value);
2064   entry->set_next(bucket(index));
2065   _buckets[index].set_entry(entry);
2066   assert(entry->symbol() != NULL, "SymbolHashMapEntry symbol is NULL");
2067 }
2068 
2069 SymbolHashMapEntry* SymbolHashMap::find_entry(Symbol* sym) {
2070   assert(sym != NULL, "SymbolHashMap::find_entry - symbol is NULL");
2071   char *str = sym->as_utf8();
2072   int   len = sym->utf8_length();
2073   unsigned int hash = SymbolHashMap::compute_hash(str, len);
2074   unsigned int index = hash % table_size();
2075   for (SymbolHashMapEntry *en = bucket(index); en != NULL; en = en->next()) {
2076     assert(en->symbol() != NULL, "SymbolHashMapEntry symbol is NULL");
2077     if (en->hash() == hash && en->symbol() == sym) {
2078       return en;
2079     }
2080   }
2081   return NULL;
2082 }