1 /*
   2  * Copyright (c) 1997, 2012, 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.hpp"
  28 #include "classfile/symbolTable.hpp"
  29 #include "classfile/systemDictionary.hpp"
  30 #include "classfile/vmSymbols.hpp"
  31 #include "interpreter/linkResolver.hpp"
  32 #include "memory/metadataFactory.hpp"
  33 #include "memory/oopFactory.hpp"
  34 #include "oops/constantPool.hpp"
  35 #include "oops/instanceKlass.hpp"
  36 #include "oops/objArrayKlass.hpp"
  37 #include "prims/jvmtiRedefineClasses.hpp"
  38 #include "runtime/fieldType.hpp"
  39 #include "runtime/init.hpp"
  40 #include "runtime/javaCalls.hpp"
  41 #include "runtime/signature.hpp"
  42 #include "runtime/vframe.hpp"
  43 
  44 ConstantPool* ConstantPool::allocate(ClassLoaderData* loader_data, int length, TRAPS) {
  45   // Tags are RW but comment below applies to tags also.
  46   Array<u1>* tags = MetadataFactory::new_writeable_array<u1>(loader_data, length, 0, CHECK_NULL);
  47 
  48   int size = ConstantPool::size(length);
  49 
  50   // CDS considerations:
  51   // Allocate read-write but may be able to move to read-only at dumping time
  52   // if all the klasses are resolved.  The only other field that is writable is
  53   // the resolved_references array, which is recreated at startup time.
  54   // But that could be moved to InstanceKlass (although a pain to access from
  55   // assembly code).  Maybe it could be moved to the cpCache which is RW.
  56   return new (loader_data, size, false, THREAD) ConstantPool(tags);
  57 }
  58 
  59 ConstantPool::ConstantPool(Array<u1>* tags) {
  60   set_length(tags->length());
  61   set_tags(NULL);
  62   set_cache(NULL);
  63   set_reference_map(NULL);
  64   set_resolved_references(NULL);
  65   set_operands(NULL);
  66   set_pool_holder(NULL);
  67   set_flags(0);
  68   // only set to non-zero if constant pool is merged by RedefineClasses
  69   set_orig_length(0);
  70   set_lock(new Monitor(Monitor::nonleaf + 2, "A constant pool lock"));
  71   // all fields are initialized; needed for GC
  72   set_on_stack(false);
  73 
  74   // initialize tag array
  75   int length = tags->length();
  76   for (int index = 0; index < length; index++) {
  77     tags->at_put(index, JVM_CONSTANT_Invalid);
  78   }
  79   set_tags(tags);
  80 }
  81 
  82 void ConstantPool::deallocate_contents(ClassLoaderData* loader_data) {
  83   MetadataFactory::free_metadata(loader_data, cache());
  84   set_cache(NULL);
  85   MetadataFactory::free_array<jushort>(loader_data, operands());
  86   set_operands(NULL);
  87 
  88   release_C_heap_structures();
  89 
  90   // free tag array
  91   MetadataFactory::free_array<u1>(loader_data, tags());
  92   set_tags(NULL);
  93 }
  94 
  95 void ConstantPool::release_C_heap_structures() {
  96   // walk constant pool and decrement symbol reference counts
  97   unreference_symbols();
  98 
  99   delete _lock;
 100   set_lock(NULL);
 101 }
 102 
 103 void ConstantPool::set_flag_at(FlagBit fb) {
 104   const int MAX_STATE_CHANGES = 2;
 105   for (int i = MAX_STATE_CHANGES + 10; i > 0; i--) {
 106     int oflags = _flags;
 107     int nflags = oflags | (1 << (int)fb);
 108     if (Atomic::cmpxchg(nflags, &_flags, oflags) == oflags)
 109       return;
 110   }
 111   assert(false, "failed to cmpxchg flags");
 112   _flags |= (1 << (int)fb);     // better than nothing
 113 }
 114 
 115 objArrayOop ConstantPool::resolved_references() const {
 116   return (objArrayOop)JNIHandles::resolve(_resolved_references);
 117 }
 118 
 119 // Create resolved_references array and mapping array for original cp indexes
 120 // The ldc bytecode was rewritten to have the resolved reference array index so need a way
 121 // to map it back for resolving and some unlikely miscellaneous uses.
 122 // The objects created by invokedynamic are appended to this list.
 123 void ConstantPool::initialize_resolved_references(ClassLoaderData* loader_data,
 124                                                   intStack reference_map,
 125                                                   int constant_pool_map_length,
 126                                                    TRAPS) {
 127   // Initialized the resolved object cache.
 128   int map_length = reference_map.length();
 129   if (map_length > 0) {
 130     // Only need mapping back to constant pool entries.  The map isn't used for
 131     // invokedynamic resolved_reference entries.  The constant pool cache index
 132     // has the mapping back to both the constant pool and to the resolved
 133     // reference index.
 134     if (constant_pool_map_length > 0) {
 135       Array<u2>* om = MetadataFactory::new_array<u2>(loader_data, map_length, CHECK);
 136 
 137       for (int i = 0; i < constant_pool_map_length; i++) {
 138         int x = reference_map.at(i);
 139         assert(x == (int)(jushort) x, "klass index is too big");
 140         om->at_put(i, (jushort)x);
 141       }
 142       set_reference_map(om);
 143     }
 144 
 145     // Create Java array for holding resolved strings, methodHandles,
 146     // methodTypes, invokedynamic and invokehandle appendix objects, etc.
 147     objArrayOop stom = oopFactory::new_objArray(SystemDictionary::Object_klass(), map_length, CHECK);
 148     Handle refs_handle (THREAD, (oop)stom);  // must handleize.
 149     set_resolved_references(loader_data->add_handle(refs_handle));
 150   }
 151 }
 152 
 153 // CDS support. Create a new resolved_references array.
 154 void ConstantPool::restore_unshareable_info(TRAPS) {
 155 
 156   // restore the C++ vtable from the shared archive
 157   restore_vtable();
 158 
 159   if (SystemDictionary::Object_klass_loaded()) {
 160     // Recreate the object array and add to ClassLoaderData.
 161     int map_length = resolved_reference_length();
 162     if (map_length > 0) {
 163       objArrayOop stom = oopFactory::new_objArray(SystemDictionary::Object_klass(), map_length, CHECK);
 164       Handle refs_handle (THREAD, (oop)stom);  // must handleize.
 165 
 166       ClassLoaderData* loader_data = pool_holder()->class_loader_data();
 167       set_resolved_references(loader_data->add_handle(refs_handle));
 168     }
 169 
 170     // Also need to recreate the mutex.  Make sure this matches the constructor
 171     set_lock(new Monitor(Monitor::nonleaf + 2, "A constant pool lock"));
 172   }
 173 }
 174 
 175 void ConstantPool::remove_unshareable_info() {
 176   // Resolved references are not in the shared archive.
 177   // Save the length for restoration.  It is not necessarily the same length
 178   // as reference_map.length() if invokedynamic is saved.
 179   set_resolved_reference_length(
 180     resolved_references() != NULL ? resolved_references()->length() : 0);
 181   set_resolved_references(NULL);
 182   set_lock(NULL);
 183 }
 184 
 185 int ConstantPool::cp_to_object_index(int cp_index) {
 186   // this is harder don't do this so much.
 187   for (int i = 0; i< reference_map()->length(); i++) {
 188     if (reference_map()->at(i) == cp_index) return i;
 189     // Zero entry is divider between constant pool indices for strings,
 190     // method handles and method types. After that the index is a constant
 191     // pool cache index for invokedynamic.  Stop when zero (which can never
 192     // be a constant pool index)
 193     if (reference_map()->at(i) == 0) break;
 194   }
 195   // We might not find the index.
 196   return _no_index_sentinel;
 197 }
 198 
 199 Klass* ConstantPool::klass_at_impl(constantPoolHandle this_oop, int which, TRAPS) {
 200   // A resolved constantPool entry will contain a Klass*, otherwise a Symbol*.
 201   // It is not safe to rely on the tag bit's here, since we don't have a lock, and the entry and
 202   // tag is not updated atomicly.
 203 
 204   CPSlot entry = this_oop->slot_at(which);
 205   if (entry.is_resolved()) {
 206     assert(entry.get_klass()->is_klass(), "must be");
 207     // Already resolved - return entry.
 208     return entry.get_klass();
 209   }
 210 
 211   // Acquire lock on constant oop while doing update. After we get the lock, we check if another object
 212   // already has updated the object
 213   assert(THREAD->is_Java_thread(), "must be a Java thread");
 214   bool do_resolve = false;
 215   bool in_error = false;
 216 
 217   // Create a handle for the mirror. This will preserve the resolved class
 218   // until the loader_data is registered.
 219   Handle mirror_handle;
 220 
 221   Symbol* name = NULL;
 222   Handle       loader;
 223   {  MonitorLockerEx ml(this_oop->lock());
 224 
 225     if (this_oop->tag_at(which).is_unresolved_klass()) {
 226       if (this_oop->tag_at(which).is_unresolved_klass_in_error()) {
 227         in_error = true;
 228       } else {
 229         do_resolve = true;
 230         name   = this_oop->unresolved_klass_at(which);
 231         loader = Handle(THREAD, this_oop->pool_holder()->class_loader());
 232       }
 233     }
 234   } // unlocking constantPool
 235 
 236 
 237   // The original attempt to resolve this constant pool entry failed so find the
 238   // original error and throw it again (JVMS 5.4.3).
 239   if (in_error) {
 240     Symbol* error = SystemDictionary::find_resolution_error(this_oop, which);
 241     guarantee(error != (Symbol*)NULL, "tag mismatch with resolution error table");
 242     ResourceMark rm;
 243     // exception text will be the class name
 244     const char* className = this_oop->unresolved_klass_at(which)->as_C_string();
 245     THROW_MSG_0(error, className);
 246   }
 247 
 248   if (do_resolve) {
 249     // this_oop must be unlocked during resolve_or_fail
 250     oop protection_domain = this_oop->pool_holder()->protection_domain();
 251     Handle h_prot (THREAD, protection_domain);
 252     Klass* k_oop = SystemDictionary::resolve_or_fail(name, loader, h_prot, true, THREAD);
 253     KlassHandle k;
 254     if (!HAS_PENDING_EXCEPTION) {
 255       k = KlassHandle(THREAD, k_oop);
 256       // preserve the resolved klass.
 257       mirror_handle = Handle(THREAD, k_oop->java_mirror());
 258       // Do access check for klasses
 259       verify_constant_pool_resolve(this_oop, k, THREAD);
 260     }
 261 
 262     // Failed to resolve class. We must record the errors so that subsequent attempts
 263     // to resolve this constant pool entry fail with the same error (JVMS 5.4.3).
 264     if (HAS_PENDING_EXCEPTION) {
 265       ResourceMark rm;
 266       Symbol* error = PENDING_EXCEPTION->klass()->name();
 267 
 268       bool throw_orig_error = false;
 269       {
 270         MonitorLockerEx ml(this_oop->lock());
 271 
 272         // some other thread has beaten us and has resolved the class.
 273         if (this_oop->tag_at(which).is_klass()) {
 274           CLEAR_PENDING_EXCEPTION;
 275           entry = this_oop->resolved_klass_at(which);
 276           return entry.get_klass();
 277         }
 278 
 279         if (!PENDING_EXCEPTION->
 280               is_a(SystemDictionary::LinkageError_klass())) {
 281           // Just throw the exception and don't prevent these classes from
 282           // being loaded due to virtual machine errors like StackOverflow
 283           // and OutOfMemoryError, etc, or if the thread was hit by stop()
 284           // Needs clarification to section 5.4.3 of the VM spec (see 6308271)
 285         }
 286         else if (!this_oop->tag_at(which).is_unresolved_klass_in_error()) {
 287           SystemDictionary::add_resolution_error(this_oop, which, error);
 288           this_oop->tag_at_put(which, JVM_CONSTANT_UnresolvedClassInError);
 289         } else {
 290           // some other thread has put the class in error state.
 291           error = SystemDictionary::find_resolution_error(this_oop, which);
 292           assert(error != NULL, "checking");
 293           throw_orig_error = true;
 294         }
 295       } // unlocked
 296 
 297       if (throw_orig_error) {
 298         CLEAR_PENDING_EXCEPTION;
 299         ResourceMark rm;
 300         const char* className = this_oop->unresolved_klass_at(which)->as_C_string();
 301         THROW_MSG_0(error, className);
 302       }
 303 
 304       return 0;
 305     }
 306 
 307     if (TraceClassResolution && !k()->oop_is_array()) {
 308       // skip resolving the constant pool so that this code get's
 309       // called the next time some bytecodes refer to this class.
 310       ResourceMark rm;
 311       int line_number = -1;
 312       const char * source_file = NULL;
 313       if (JavaThread::current()->has_last_Java_frame()) {
 314         // try to identify the method which called this function.
 315         vframeStream vfst(JavaThread::current());
 316         if (!vfst.at_end()) {
 317           line_number = vfst.method()->line_number_from_bci(vfst.bci());
 318           Symbol* s = vfst.method()->method_holder()->source_file_name();
 319           if (s != NULL) {
 320             source_file = s->as_C_string();
 321           }
 322         }
 323       }
 324       if (k() != this_oop->pool_holder()) {
 325         // only print something if the classes are different
 326         if (source_file != NULL) {
 327           tty->print("RESOLVE %s %s %s:%d\n",
 328                      this_oop->pool_holder()->external_name(),
 329                      InstanceKlass::cast(k())->external_name(), source_file, line_number);
 330         } else {
 331           tty->print("RESOLVE %s %s\n",
 332                      this_oop->pool_holder()->external_name(),
 333                      InstanceKlass::cast(k())->external_name());
 334         }
 335       }
 336       return k();
 337     } else {
 338       MonitorLockerEx ml(this_oop->lock());
 339       // Only updated constant pool - if it is resolved.
 340       do_resolve = this_oop->tag_at(which).is_unresolved_klass();
 341       if (do_resolve) {
 342         ClassLoaderData* this_key = this_oop->pool_holder()->class_loader_data();
 343         if (!this_key->is_the_null_class_loader_data()) {
 344           this_key->record_dependency(k(), CHECK_NULL); // Can throw OOM
 345         }
 346         this_oop->klass_at_put(which, k());
 347       }
 348     }
 349   }
 350 
 351   entry = this_oop->resolved_klass_at(which);
 352   assert(entry.is_resolved() && entry.get_klass()->is_klass(), "must be resolved at this point");
 353   return entry.get_klass();
 354 }
 355 
 356 
 357 // Does not update ConstantPool* - to avoid any exception throwing. Used
 358 // by compiler and exception handling.  Also used to avoid classloads for
 359 // instanceof operations. Returns NULL if the class has not been loaded or
 360 // if the verification of constant pool failed
 361 Klass* ConstantPool::klass_at_if_loaded(constantPoolHandle this_oop, int which) {
 362   CPSlot entry = this_oop->slot_at(which);
 363   if (entry.is_resolved()) {
 364     assert(entry.get_klass()->is_klass(), "must be");
 365     return entry.get_klass();
 366   } else {
 367     assert(entry.is_unresolved(), "must be either symbol or klass");
 368     Thread *thread = Thread::current();
 369     Symbol* name = entry.get_symbol();
 370     oop loader = this_oop->pool_holder()->class_loader();
 371     oop protection_domain = this_oop->pool_holder()->protection_domain();
 372     Handle h_prot (thread, protection_domain);
 373     Handle h_loader (thread, loader);
 374     Klass* k = SystemDictionary::find(name, h_loader, h_prot, thread);
 375 
 376     if (k != NULL) {
 377       // Make sure that resolving is legal
 378       EXCEPTION_MARK;
 379       KlassHandle klass(THREAD, k);
 380       // return NULL if verification fails
 381       verify_constant_pool_resolve(this_oop, klass, THREAD);
 382       if (HAS_PENDING_EXCEPTION) {
 383         CLEAR_PENDING_EXCEPTION;
 384         return NULL;
 385       }
 386       return klass();
 387     } else {
 388       return k;
 389     }
 390   }
 391 }
 392 
 393 
 394 Klass* ConstantPool::klass_ref_at_if_loaded(constantPoolHandle this_oop, int which) {
 395   return klass_at_if_loaded(this_oop, this_oop->klass_ref_index_at(which));
 396 }
 397 
 398 
 399 // This is an interface for the compiler that allows accessing non-resolved entries
 400 // in the constant pool - but still performs the validations tests. Must be used
 401 // in a pre-parse of the compiler - to determine what it can do and not do.
 402 // Note: We cannot update the ConstantPool from the vm_thread.
 403 Klass* ConstantPool::klass_ref_at_if_loaded_check(constantPoolHandle this_oop, int index, TRAPS) {
 404   int which = this_oop->klass_ref_index_at(index);
 405   CPSlot entry = this_oop->slot_at(which);
 406   if (entry.is_resolved()) {
 407     assert(entry.get_klass()->is_klass(), "must be");
 408     return entry.get_klass();
 409   } else {
 410     assert(entry.is_unresolved(), "must be either symbol or klass");
 411     Symbol*  name  = entry.get_symbol();
 412     oop loader = this_oop->pool_holder()->class_loader();
 413     oop protection_domain = this_oop->pool_holder()->protection_domain();
 414     Handle h_loader(THREAD, loader);
 415     Handle h_prot  (THREAD, protection_domain);
 416     KlassHandle k(THREAD, SystemDictionary::find(name, h_loader, h_prot, THREAD));
 417 
 418     // Do access check for klasses
 419     if( k.not_null() ) verify_constant_pool_resolve(this_oop, k, CHECK_NULL);
 420     return k();
 421   }
 422 }
 423 
 424 
 425 Method* ConstantPool::method_at_if_loaded(constantPoolHandle cpool,
 426                                                    int which) {
 427   if (cpool->cache() == NULL)  return NULL;  // nothing to load yet
 428   int cache_index = decode_cpcache_index(which, true);
 429   if (!(cache_index >= 0 && cache_index < cpool->cache()->length())) {
 430     // FIXME: should be an assert
 431     if (PrintMiscellaneous && (Verbose||WizardMode)) {
 432       tty->print_cr("bad operand %d in:", which); cpool->print();
 433     }
 434     return NULL;
 435   }
 436   ConstantPoolCacheEntry* e = cpool->cache()->entry_at(cache_index);
 437   return e->method_if_resolved(cpool);
 438 }
 439 
 440 
 441 bool ConstantPool::has_appendix_at_if_loaded(constantPoolHandle cpool, int which) {
 442   if (cpool->cache() == NULL)  return false;  // nothing to load yet
 443   int cache_index = decode_cpcache_index(which, true);
 444   ConstantPoolCacheEntry* e = cpool->cache()->entry_at(cache_index);
 445   return e->has_appendix();
 446 }
 447 
 448 oop ConstantPool::appendix_at_if_loaded(constantPoolHandle cpool, int which) {
 449   if (cpool->cache() == NULL)  return NULL;  // nothing to load yet
 450   int cache_index = decode_cpcache_index(which, true);
 451   ConstantPoolCacheEntry* e = cpool->cache()->entry_at(cache_index);
 452   return e->appendix_if_resolved(cpool);
 453 }
 454 
 455 
 456 bool ConstantPool::has_method_type_at_if_loaded(constantPoolHandle cpool, int which) {
 457   if (cpool->cache() == NULL)  return false;  // nothing to load yet
 458   int cache_index = decode_cpcache_index(which, true);
 459   ConstantPoolCacheEntry* e = cpool->cache()->entry_at(cache_index);
 460   return e->has_method_type();
 461 }
 462 
 463 oop ConstantPool::method_type_at_if_loaded(constantPoolHandle cpool, int which) {
 464   if (cpool->cache() == NULL)  return NULL;  // nothing to load yet
 465   int cache_index = decode_cpcache_index(which, true);
 466   ConstantPoolCacheEntry* e = cpool->cache()->entry_at(cache_index);
 467   return e->method_type_if_resolved(cpool);
 468 }
 469 
 470 
 471 Symbol* ConstantPool::impl_name_ref_at(int which, bool uncached) {
 472   int name_index = name_ref_index_at(impl_name_and_type_ref_index_at(which, uncached));
 473   return symbol_at(name_index);
 474 }
 475 
 476 
 477 Symbol* ConstantPool::impl_signature_ref_at(int which, bool uncached) {
 478   int signature_index = signature_ref_index_at(impl_name_and_type_ref_index_at(which, uncached));
 479   return symbol_at(signature_index);
 480 }
 481 
 482 
 483 int ConstantPool::impl_name_and_type_ref_index_at(int which, bool uncached) {
 484   int i = which;
 485   if (!uncached && cache() != NULL) {
 486     if (ConstantPool::is_invokedynamic_index(which)) {
 487       // Invokedynamic index is index into resolved_references
 488       int pool_index = invokedynamic_cp_cache_entry_at(which)->constant_pool_index();
 489       pool_index = invoke_dynamic_name_and_type_ref_index_at(pool_index);
 490       assert(tag_at(pool_index).is_name_and_type(), "");
 491       return pool_index;
 492     }
 493     // change byte-ordering and go via cache
 494     i = remap_instruction_operand_from_cache(which);
 495   } else {
 496     if (tag_at(which).is_invoke_dynamic()) {
 497       int pool_index = invoke_dynamic_name_and_type_ref_index_at(which);
 498       assert(tag_at(pool_index).is_name_and_type(), "");
 499       return pool_index;
 500     }
 501   }
 502   assert(tag_at(i).is_field_or_method(), "Corrupted constant pool");
 503   assert(!tag_at(i).is_invoke_dynamic(), "Must be handled above");
 504   jint ref_index = *int_at_addr(i);
 505   return extract_high_short_from_int(ref_index);
 506 }
 507 
 508 
 509 int ConstantPool::impl_klass_ref_index_at(int which, bool uncached) {
 510   guarantee(!ConstantPool::is_invokedynamic_index(which),
 511             "an invokedynamic instruction does not have a klass");
 512   int i = which;
 513   if (!uncached && cache() != NULL) {
 514     // change byte-ordering and go via cache
 515     i = remap_instruction_operand_from_cache(which);
 516   }
 517   assert(tag_at(i).is_field_or_method(), "Corrupted constant pool");
 518   jint ref_index = *int_at_addr(i);
 519   return extract_low_short_from_int(ref_index);
 520 }
 521 
 522 
 523 
 524 int ConstantPool::remap_instruction_operand_from_cache(int operand) {
 525   int cpc_index = operand;
 526   DEBUG_ONLY(cpc_index -= CPCACHE_INDEX_TAG);
 527   assert((int)(u2)cpc_index == cpc_index, "clean u2");
 528   int member_index = cache()->entry_at(cpc_index)->constant_pool_index();
 529   return member_index;
 530 }
 531 
 532 
 533 void ConstantPool::verify_constant_pool_resolve(constantPoolHandle this_oop, KlassHandle k, TRAPS) {
 534  if (k->oop_is_instance() || k->oop_is_objArray()) {
 535     instanceKlassHandle holder (THREAD, this_oop->pool_holder());
 536     Klass* elem_oop = k->oop_is_instance() ? k() : ObjArrayKlass::cast(k())->bottom_klass();
 537     KlassHandle element (THREAD, elem_oop);
 538 
 539     // The element type could be a typeArray - we only need the access check if it is
 540     // an reference to another class
 541     if (element->oop_is_instance()) {
 542       LinkResolver::check_klass_accessability(holder, element, CHECK);
 543     }
 544   }
 545 }
 546 
 547 
 548 int ConstantPool::name_ref_index_at(int which_nt) {
 549   jint ref_index = name_and_type_at(which_nt);
 550   return extract_low_short_from_int(ref_index);
 551 }
 552 
 553 
 554 int ConstantPool::signature_ref_index_at(int which_nt) {
 555   jint ref_index = name_and_type_at(which_nt);
 556   return extract_high_short_from_int(ref_index);
 557 }
 558 
 559 
 560 Klass* ConstantPool::klass_ref_at(int which, TRAPS) {
 561   return klass_at(klass_ref_index_at(which), CHECK_NULL);
 562 }
 563 
 564 
 565 Symbol* ConstantPool::klass_name_at(int which) {
 566   assert(tag_at(which).is_unresolved_klass() || tag_at(which).is_klass(),
 567          "Corrupted constant pool");
 568   // A resolved constantPool entry will contain a Klass*, otherwise a Symbol*.
 569   // It is not safe to rely on the tag bit's here, since we don't have a lock, and the entry and
 570   // tag is not updated atomicly.
 571   CPSlot entry = slot_at(which);
 572   if (entry.is_resolved()) {
 573     // Already resolved - return entry's name.
 574     assert(entry.get_klass()->is_klass(), "must be");
 575     return entry.get_klass()->name();
 576   } else {
 577     assert(entry.is_unresolved(), "must be either symbol or klass");
 578     return entry.get_symbol();
 579   }
 580 }
 581 
 582 Symbol* ConstantPool::klass_ref_at_noresolve(int which) {
 583   jint ref_index = klass_ref_index_at(which);
 584   return klass_at_noresolve(ref_index);
 585 }
 586 
 587 Symbol* ConstantPool::uncached_klass_ref_at_noresolve(int which) {
 588   jint ref_index = uncached_klass_ref_index_at(which);
 589   return klass_at_noresolve(ref_index);
 590 }
 591 
 592 char* ConstantPool::string_at_noresolve(int which) {
 593   Symbol* s = unresolved_string_at(which);
 594   if (s == NULL) {
 595     return (char*)"<pseudo-string>";
 596   } else {
 597     return unresolved_string_at(which)->as_C_string();
 598   }
 599 }
 600 
 601 BasicType ConstantPool::basic_type_for_signature_at(int which) {
 602   return FieldType::basic_type(symbol_at(which));
 603 }
 604 
 605 
 606 void ConstantPool::resolve_string_constants_impl(constantPoolHandle this_oop, TRAPS) {
 607   for (int index = 1; index < this_oop->length(); index++) { // Index 0 is unused
 608     if (this_oop->tag_at(index).is_string()) {
 609       this_oop->string_at(index, CHECK);
 610     }
 611   }
 612 }
 613 
 614 // Resolve all the classes in the constant pool.  If they are all resolved,
 615 // the constant pool is read-only.  Enhancement: allocate cp entries to
 616 // another metaspace, and copy to read-only or read-write space if this
 617 // bit is set.
 618 bool ConstantPool::resolve_class_constants(TRAPS) {
 619   constantPoolHandle cp(THREAD, this);
 620   for (int index = 1; index < length(); index++) { // Index 0 is unused
 621     if (tag_at(index).is_unresolved_klass() &&
 622         klass_at_if_loaded(cp, index) == NULL) {
 623       return false;
 624   }
 625   }
 626   // set_preresolution(); or some bit for future use
 627   return true;
 628 }
 629 
 630 // If resolution for MethodHandle or MethodType fails, save the exception
 631 // in the resolution error table, so that the same exception is thrown again.
 632 void ConstantPool::save_and_throw_exception(constantPoolHandle this_oop, int which,
 633                                      int tag, TRAPS) {
 634   ResourceMark rm;
 635   Symbol* error = PENDING_EXCEPTION->klass()->name();
 636   MonitorLockerEx ml(this_oop->lock());  // lock cpool to change tag.
 637 
 638   int error_tag = (tag == JVM_CONSTANT_MethodHandle) ?
 639            JVM_CONSTANT_MethodHandleInError : JVM_CONSTANT_MethodTypeInError;
 640 
 641   if (!PENDING_EXCEPTION->
 642     is_a(SystemDictionary::LinkageError_klass())) {
 643     // Just throw the exception and don't prevent these classes from
 644     // being loaded due to virtual machine errors like StackOverflow
 645     // and OutOfMemoryError, etc, or if the thread was hit by stop()
 646     // Needs clarification to section 5.4.3 of the VM spec (see 6308271)
 647 
 648   } else if (this_oop->tag_at(which).value() != error_tag) {
 649     SystemDictionary::add_resolution_error(this_oop, which, error);
 650     this_oop->tag_at_put(which, error_tag);
 651   } else {
 652     // some other thread has put the class in error state.
 653     error = SystemDictionary::find_resolution_error(this_oop, which);
 654     assert(error != NULL, "checking");
 655     CLEAR_PENDING_EXCEPTION;
 656     THROW_MSG(error, "");
 657   }
 658 }
 659 
 660 
 661 // Called to resolve constants in the constant pool and return an oop.
 662 // Some constant pool entries cache their resolved oop. This is also
 663 // called to create oops from constants to use in arguments for invokedynamic
 664 oop ConstantPool::resolve_constant_at_impl(constantPoolHandle this_oop, int index, int cache_index, TRAPS) {
 665   oop result_oop = NULL;
 666   Handle throw_exception;
 667 
 668   if (cache_index == _possible_index_sentinel) {
 669     // It is possible that this constant is one which is cached in the objects.
 670     // We'll do a linear search.  This should be OK because this usage is rare.
 671     assert(index > 0, "valid index");
 672     cache_index = this_oop->cp_to_object_index(index);
 673   }
 674   assert(cache_index == _no_index_sentinel || cache_index >= 0, "");
 675   assert(index == _no_index_sentinel || index >= 0, "");
 676 
 677   if (cache_index >= 0) {
 678     result_oop = this_oop->resolved_references()->obj_at(cache_index);
 679     if (result_oop != NULL) {
 680       return result_oop;
 681       // That was easy...
 682     }
 683     index = this_oop->object_to_cp_index(cache_index);
 684   }
 685 
 686   jvalue prim_value;  // temp used only in a few cases below
 687 
 688   int tag_value = this_oop->tag_at(index).value();
 689 
 690   switch (tag_value) {
 691 
 692   case JVM_CONSTANT_UnresolvedClass:
 693   case JVM_CONSTANT_UnresolvedClassInError:
 694   case JVM_CONSTANT_Class:
 695     {
 696       assert(cache_index == _no_index_sentinel, "should not have been set");
 697       Klass* resolved = klass_at_impl(this_oop, index, CHECK_NULL);
 698       // ldc wants the java mirror.
 699       result_oop = resolved->java_mirror();
 700       break;
 701     }
 702 
 703   case JVM_CONSTANT_String:
 704     assert(cache_index != _no_index_sentinel, "should have been set");
 705     if (this_oop->is_pseudo_string_at(index)) {
 706       result_oop = this_oop->pseudo_string_at(index, cache_index);
 707       break;
 708     }
 709     result_oop = string_at_impl(this_oop, index, cache_index, CHECK_NULL);
 710     break;
 711 
 712   case JVM_CONSTANT_Object:
 713     result_oop = this_oop->object_at(index);
 714     break;
 715 
 716   case JVM_CONSTANT_MethodHandleInError:
 717   case JVM_CONSTANT_MethodTypeInError:
 718     {
 719       Symbol* error = SystemDictionary::find_resolution_error(this_oop, index);
 720       guarantee(error != (Symbol*)NULL, "tag mismatch with resolution error table");
 721       ResourceMark rm;
 722       THROW_MSG_0(error, "");
 723       break;
 724     }
 725 
 726   case JVM_CONSTANT_MethodHandle:
 727     {
 728       int ref_kind                 = this_oop->method_handle_ref_kind_at(index);
 729       int callee_index             = this_oop->method_handle_klass_index_at(index);
 730       Symbol*  name =      this_oop->method_handle_name_ref_at(index);
 731       Symbol*  signature = this_oop->method_handle_signature_ref_at(index);
 732       if (PrintMiscellaneous)
 733         tty->print_cr("resolve JVM_CONSTANT_MethodHandle:%d [%d/%d/%d] %s.%s",
 734                       ref_kind, index, this_oop->method_handle_index_at(index),
 735                       callee_index, name->as_C_string(), signature->as_C_string());
 736       KlassHandle callee;
 737       { Klass* k = klass_at_impl(this_oop, callee_index, CHECK_NULL);
 738         callee = KlassHandle(THREAD, k);
 739       }
 740       KlassHandle klass(THREAD, this_oop->pool_holder());
 741       Handle value = SystemDictionary::link_method_handle_constant(klass, ref_kind,
 742                                                                    callee, name, signature,
 743                                                                    THREAD);
 744       result_oop = value();
 745       if (HAS_PENDING_EXCEPTION) {
 746         save_and_throw_exception(this_oop, index, tag_value, CHECK_NULL);
 747       }
 748       break;
 749     }
 750 
 751   case JVM_CONSTANT_MethodType:
 752     {
 753       Symbol*  signature = this_oop->method_type_signature_at(index);
 754       if (PrintMiscellaneous)
 755         tty->print_cr("resolve JVM_CONSTANT_MethodType [%d/%d] %s",
 756                       index, this_oop->method_type_index_at(index),
 757                       signature->as_C_string());
 758       KlassHandle klass(THREAD, this_oop->pool_holder());
 759       Handle value = SystemDictionary::find_method_handle_type(signature, klass, THREAD);
 760       result_oop = value();
 761       if (HAS_PENDING_EXCEPTION) {
 762         save_and_throw_exception(this_oop, index, tag_value, CHECK_NULL);
 763       }
 764       break;
 765     }
 766 
 767   case JVM_CONSTANT_Integer:
 768     assert(cache_index == _no_index_sentinel, "should not have been set");
 769     prim_value.i = this_oop->int_at(index);
 770     result_oop = java_lang_boxing_object::create(T_INT, &prim_value, CHECK_NULL);
 771     break;
 772 
 773   case JVM_CONSTANT_Float:
 774     assert(cache_index == _no_index_sentinel, "should not have been set");
 775     prim_value.f = this_oop->float_at(index);
 776     result_oop = java_lang_boxing_object::create(T_FLOAT, &prim_value, CHECK_NULL);
 777     break;
 778 
 779   case JVM_CONSTANT_Long:
 780     assert(cache_index == _no_index_sentinel, "should not have been set");
 781     prim_value.j = this_oop->long_at(index);
 782     result_oop = java_lang_boxing_object::create(T_LONG, &prim_value, CHECK_NULL);
 783     break;
 784 
 785   case JVM_CONSTANT_Double:
 786     assert(cache_index == _no_index_sentinel, "should not have been set");
 787     prim_value.d = this_oop->double_at(index);
 788     result_oop = java_lang_boxing_object::create(T_DOUBLE, &prim_value, CHECK_NULL);
 789     break;
 790 
 791   default:
 792     DEBUG_ONLY( tty->print_cr("*** %p: tag at CP[%d/%d] = %d",
 793                               this_oop(), index, cache_index, tag_value) );
 794     assert(false, "unexpected constant tag");
 795     break;
 796   }
 797 
 798   if (cache_index >= 0) {
 799     // Cache the oop here also.
 800     Handle result_handle(THREAD, result_oop);
 801     MonitorLockerEx ml(this_oop->lock());  // don't know if we really need this
 802     oop result = this_oop->resolved_references()->obj_at(cache_index);
 803     // Benign race condition:  resolved_references may already be filled in while we were trying to lock.
 804     // The important thing here is that all threads pick up the same result.
 805     // It doesn't matter which racing thread wins, as long as only one
 806     // result is used by all threads, and all future queries.
 807     // That result may be either a resolved constant or a failure exception.
 808     if (result == NULL) {
 809       this_oop->resolved_references()->obj_at_put(cache_index, result_handle());
 810       return result_handle();
 811     } else {
 812       // Return the winning thread's result.  This can be different than
 813       // result_handle() for MethodHandles.
 814       return result;
 815     }
 816   } else {
 817     return result_oop;
 818   }
 819 }
 820 
 821 oop ConstantPool::uncached_string_at(int which, TRAPS) {
 822   Symbol* sym = unresolved_string_at(which);
 823   oop str = StringTable::intern(sym, CHECK_(NULL));
 824   assert(java_lang_String::is_instance(str), "must be string");
 825   return str;
 826 }
 827 
 828 
 829 oop ConstantPool::resolve_bootstrap_specifier_at_impl(constantPoolHandle this_oop, int index, TRAPS) {
 830   assert(this_oop->tag_at(index).is_invoke_dynamic(), "Corrupted constant pool");
 831 
 832   Handle bsm;
 833   int argc;
 834   {
 835     // JVM_CONSTANT_InvokeDynamic is an ordered pair of [bootm, name&type], plus optional arguments
 836     // The bootm, being a JVM_CONSTANT_MethodHandle, has its own cache entry.
 837     // It is accompanied by the optional arguments.
 838     int bsm_index = this_oop->invoke_dynamic_bootstrap_method_ref_index_at(index);
 839     oop bsm_oop = this_oop->resolve_possibly_cached_constant_at(bsm_index, CHECK_NULL);
 840     if (!java_lang_invoke_MethodHandle::is_instance(bsm_oop)) {
 841       THROW_MSG_NULL(vmSymbols::java_lang_LinkageError(), "BSM not an MethodHandle");
 842     }
 843 
 844     // Extract the optional static arguments.
 845     argc = this_oop->invoke_dynamic_argument_count_at(index);
 846     if (argc == 0)  return bsm_oop;
 847 
 848     bsm = Handle(THREAD, bsm_oop);
 849   }
 850 
 851   objArrayHandle info;
 852   {
 853     objArrayOop info_oop = oopFactory::new_objArray(SystemDictionary::Object_klass(), 1+argc, CHECK_NULL);
 854     info = objArrayHandle(THREAD, info_oop);
 855   }
 856 
 857   info->obj_at_put(0, bsm());
 858   for (int i = 0; i < argc; i++) {
 859     int arg_index = this_oop->invoke_dynamic_argument_index_at(index, i);
 860     oop arg_oop = this_oop->resolve_possibly_cached_constant_at(arg_index, CHECK_NULL);
 861     info->obj_at_put(1+i, arg_oop);
 862   }
 863 
 864   return info();
 865 }
 866 
 867 oop ConstantPool::string_at_impl(constantPoolHandle this_oop, int which, int obj_index, TRAPS) {
 868   // If the string has already been interned, this entry will be non-null
 869   oop str = this_oop->resolved_references()->obj_at(obj_index);
 870   if (str != NULL) return str;
 871 
 872       Symbol* sym = this_oop->unresolved_string_at(which);
 873   str = StringTable::intern(sym, CHECK_(NULL));
 874   this_oop->string_at_put(which, obj_index, str);
 875   assert(java_lang_String::is_instance(str), "must be string");
 876   return str;
 877 }
 878 
 879 
 880 bool ConstantPool::klass_name_at_matches(instanceKlassHandle k,
 881                                                 int which) {
 882   // Names are interned, so we can compare Symbol*s directly
 883   Symbol* cp_name = klass_name_at(which);
 884   return (cp_name == k->name());
 885 }
 886 
 887 
 888 // Iterate over symbols and decrement ones which are Symbol*s.
 889 // This is done during GC so do not need to lock constantPool unless we
 890 // have per-thread safepoints.
 891 // Only decrement the UTF8 symbols. Unresolved classes and strings point to
 892 // these symbols but didn't increment the reference count.
 893 void ConstantPool::unreference_symbols() {
 894   for (int index = 1; index < length(); index++) { // Index 0 is unused
 895     constantTag tag = tag_at(index);
 896     if (tag.is_symbol()) {
 897       symbol_at(index)->decrement_refcount();
 898     }
 899   }
 900 }
 901 
 902 
 903 // Compare this constant pool's entry at index1 to the constant pool
 904 // cp2's entry at index2.
 905 bool ConstantPool::compare_entry_to(int index1, constantPoolHandle cp2,
 906        int index2, TRAPS) {
 907 
 908   jbyte t1 = tag_at(index1).value();
 909   jbyte t2 = cp2->tag_at(index2).value();
 910 
 911 
 912   // JVM_CONSTANT_UnresolvedClassInError is equal to JVM_CONSTANT_UnresolvedClass
 913   // when comparing
 914   if (t1 == JVM_CONSTANT_UnresolvedClassInError) {
 915     t1 = JVM_CONSTANT_UnresolvedClass;
 916   }
 917   if (t2 == JVM_CONSTANT_UnresolvedClassInError) {
 918     t2 = JVM_CONSTANT_UnresolvedClass;
 919   }
 920 
 921   if (t1 != t2) {
 922     // Not the same entry type so there is nothing else to check. Note
 923     // that this style of checking will consider resolved/unresolved
 924     // class pairs as different.
 925     // From the ConstantPool* API point of view, this is correct
 926     // behavior. See VM_RedefineClasses::merge_constant_pools() to see how this
 927     // plays out in the context of ConstantPool* merging.
 928     return false;
 929   }
 930 
 931   switch (t1) {
 932   case JVM_CONSTANT_Class:
 933   {
 934     Klass* k1 = klass_at(index1, CHECK_false);
 935     Klass* k2 = cp2->klass_at(index2, CHECK_false);
 936     if (k1 == k2) {
 937       return true;
 938     }
 939   } break;
 940 
 941   case JVM_CONSTANT_ClassIndex:
 942   {
 943     int recur1 = klass_index_at(index1);
 944     int recur2 = cp2->klass_index_at(index2);
 945     bool match = compare_entry_to(recur1, cp2, recur2, CHECK_false);
 946     if (match) {
 947       return true;
 948     }
 949   } break;
 950 
 951   case JVM_CONSTANT_Double:
 952   {
 953     jdouble d1 = double_at(index1);
 954     jdouble d2 = cp2->double_at(index2);
 955     if (d1 == d2) {
 956       return true;
 957     }
 958   } break;
 959 
 960   case JVM_CONSTANT_Fieldref:
 961   case JVM_CONSTANT_InterfaceMethodref:
 962   case JVM_CONSTANT_Methodref:
 963   {
 964     int recur1 = uncached_klass_ref_index_at(index1);
 965     int recur2 = cp2->uncached_klass_ref_index_at(index2);
 966     bool match = compare_entry_to(recur1, cp2, recur2, CHECK_false);
 967     if (match) {
 968       recur1 = uncached_name_and_type_ref_index_at(index1);
 969       recur2 = cp2->uncached_name_and_type_ref_index_at(index2);
 970       match = compare_entry_to(recur1, cp2, recur2, CHECK_false);
 971       if (match) {
 972         return true;
 973       }
 974     }
 975   } break;
 976 
 977   case JVM_CONSTANT_Float:
 978   {
 979     jfloat f1 = float_at(index1);
 980     jfloat f2 = cp2->float_at(index2);
 981     if (f1 == f2) {
 982       return true;
 983     }
 984   } break;
 985 
 986   case JVM_CONSTANT_Integer:
 987   {
 988     jint i1 = int_at(index1);
 989     jint i2 = cp2->int_at(index2);
 990     if (i1 == i2) {
 991       return true;
 992     }
 993   } break;
 994 
 995   case JVM_CONSTANT_Long:
 996   {
 997     jlong l1 = long_at(index1);
 998     jlong l2 = cp2->long_at(index2);
 999     if (l1 == l2) {
1000       return true;
1001     }
1002   } break;
1003 
1004   case JVM_CONSTANT_NameAndType:
1005   {
1006     int recur1 = name_ref_index_at(index1);
1007     int recur2 = cp2->name_ref_index_at(index2);
1008     bool match = compare_entry_to(recur1, cp2, recur2, CHECK_false);
1009     if (match) {
1010       recur1 = signature_ref_index_at(index1);
1011       recur2 = cp2->signature_ref_index_at(index2);
1012       match = compare_entry_to(recur1, cp2, recur2, CHECK_false);
1013       if (match) {
1014         return true;
1015       }
1016     }
1017   } break;
1018 
1019   case JVM_CONSTANT_StringIndex:
1020   {
1021     int recur1 = string_index_at(index1);
1022     int recur2 = cp2->string_index_at(index2);
1023     bool match = compare_entry_to(recur1, cp2, recur2, CHECK_false);
1024     if (match) {
1025       return true;
1026     }
1027   } break;
1028 
1029   case JVM_CONSTANT_UnresolvedClass:
1030   {
1031     Symbol* k1 = unresolved_klass_at(index1);
1032     Symbol* k2 = cp2->unresolved_klass_at(index2);
1033     if (k1 == k2) {
1034       return true;
1035     }
1036   } break;
1037 
1038   case JVM_CONSTANT_MethodType:
1039   {
1040     int k1 = method_type_index_at(index1);
1041     int k2 = cp2->method_type_index_at(index2);
1042     bool match = compare_entry_to(k1, cp2, k2, CHECK_false);
1043     if (match) {
1044       return true;
1045     }
1046   } break;
1047 
1048   case JVM_CONSTANT_MethodHandle:
1049   {
1050     int k1 = method_handle_ref_kind_at(index1);
1051     int k2 = cp2->method_handle_ref_kind_at(index2);
1052     if (k1 == k2) {
1053       int i1 = method_handle_index_at(index1);
1054       int i2 = cp2->method_handle_index_at(index2);
1055       bool match = compare_entry_to(i1, cp2, i2, CHECK_false);
1056       if (match) {
1057         return true;
1058       }
1059     }
1060   } break;
1061 
1062   case JVM_CONSTANT_InvokeDynamic:
1063   {
1064     int k1 = invoke_dynamic_bootstrap_method_ref_index_at(index1);
1065     int k2 = cp2->invoke_dynamic_bootstrap_method_ref_index_at(index2);
1066     bool match = compare_entry_to(k1, cp2, k2, CHECK_false);
1067     if (!match)  return false;
1068     k1 = invoke_dynamic_name_and_type_ref_index_at(index1);
1069     k2 = cp2->invoke_dynamic_name_and_type_ref_index_at(index2);
1070     match = compare_entry_to(k1, cp2, k2, CHECK_false);
1071     if (!match)  return false;
1072     int argc = invoke_dynamic_argument_count_at(index1);
1073     if (argc == cp2->invoke_dynamic_argument_count_at(index2)) {
1074       for (int j = 0; j < argc; j++) {
1075         k1 = invoke_dynamic_argument_index_at(index1, j);
1076         k2 = cp2->invoke_dynamic_argument_index_at(index2, j);
1077         match = compare_entry_to(k1, cp2, k2, CHECK_false);
1078         if (!match)  return false;
1079       }
1080       return true;           // got through loop; all elements equal
1081     }
1082   } break;
1083 
1084   case JVM_CONSTANT_String:
1085   {
1086     Symbol* s1 = unresolved_string_at(index1);
1087     Symbol* s2 = cp2->unresolved_string_at(index2);
1088     if (s1 == s2) {
1089       return true;
1090     }
1091   } break;
1092 
1093   case JVM_CONSTANT_Utf8:
1094   {
1095     Symbol* s1 = symbol_at(index1);
1096     Symbol* s2 = cp2->symbol_at(index2);
1097     if (s1 == s2) {
1098       return true;
1099     }
1100   } break;
1101 
1102   // Invalid is used as the tag for the second constant pool entry
1103   // occupied by JVM_CONSTANT_Double or JVM_CONSTANT_Long. It should
1104   // not be seen by itself.
1105   case JVM_CONSTANT_Invalid: // fall through
1106 
1107   default:
1108     ShouldNotReachHere();
1109     break;
1110   }
1111 
1112   return false;
1113 } // end compare_entry_to()
1114 
1115 
1116 // Copy this constant pool's entries at start_i to end_i (inclusive)
1117 // to the constant pool to_cp's entries starting at to_i. A total of
1118 // (end_i - start_i) + 1 entries are copied.
1119 void ConstantPool::copy_cp_to_impl(constantPoolHandle from_cp, int start_i, int end_i,
1120        constantPoolHandle to_cp, int to_i, TRAPS) {
1121 
1122   int dest_i = to_i;  // leave original alone for debug purposes
1123 
1124   for (int src_i = start_i; src_i <= end_i; /* see loop bottom */ ) {
1125     copy_entry_to(from_cp, src_i, to_cp, dest_i, CHECK);
1126 
1127     switch (from_cp->tag_at(src_i).value()) {
1128     case JVM_CONSTANT_Double:
1129     case JVM_CONSTANT_Long:
1130       // double and long take two constant pool entries
1131       src_i += 2;
1132       dest_i += 2;
1133       break;
1134 
1135     default:
1136       // all others take one constant pool entry
1137       src_i++;
1138       dest_i++;
1139       break;
1140     }
1141   }
1142 
1143   int from_oplen = operand_array_length(from_cp->operands());
1144   int old_oplen  = operand_array_length(to_cp->operands());
1145   if (from_oplen != 0) {
1146     ClassLoaderData* loader_data = to_cp->pool_holder()->class_loader_data();
1147     // append my operands to the target's operands array
1148     if (old_oplen == 0) {
1149       // Can't just reuse from_cp's operand list because of deallocation issues
1150       int len = from_cp->operands()->length();
1151       Array<u2>* new_ops = MetadataFactory::new_array<u2>(loader_data, len, CHECK);
1152       Copy::conjoint_memory_atomic(
1153           from_cp->operands()->adr_at(0), new_ops->adr_at(0), len * sizeof(u2));
1154       to_cp->set_operands(new_ops);
1155     } else {
1156       int old_len  = to_cp->operands()->length();
1157       int from_len = from_cp->operands()->length();
1158       int old_off  = old_oplen * sizeof(u2);
1159       int from_off = from_oplen * sizeof(u2);
1160       // Use the metaspace for the destination constant pool
1161       Array<u2>* new_operands = MetadataFactory::new_array<u2>(loader_data, old_len + from_len, CHECK);
1162       int fillp = 0, len = 0;
1163       // first part of dest
1164       Copy::conjoint_memory_atomic(to_cp->operands()->adr_at(0),
1165                                    new_operands->adr_at(fillp),
1166                                    (len = old_off) * sizeof(u2));
1167       fillp += len;
1168       // first part of src
1169       Copy::conjoint_memory_atomic(to_cp->operands()->adr_at(0),
1170                                    new_operands->adr_at(fillp),
1171                                    (len = from_off) * sizeof(u2));
1172       fillp += len;
1173       // second part of dest
1174       Copy::conjoint_memory_atomic(to_cp->operands()->adr_at(old_off),
1175                                    new_operands->adr_at(fillp),
1176                                    (len = old_len - old_off) * sizeof(u2));
1177       fillp += len;
1178       // second part of src
1179       Copy::conjoint_memory_atomic(to_cp->operands()->adr_at(from_off),
1180                                    new_operands->adr_at(fillp),
1181                                    (len = from_len - from_off) * sizeof(u2));
1182       fillp += len;
1183       assert(fillp == new_operands->length(), "");
1184 
1185       // Adjust indexes in the first part of the copied operands array.
1186       for (int j = 0; j < from_oplen; j++) {
1187         int offset = operand_offset_at(new_operands, old_oplen + j);
1188         assert(offset == operand_offset_at(from_cp->operands(), j), "correct copy");
1189         offset += old_len;  // every new tuple is preceded by old_len extra u2's
1190         operand_offset_at_put(new_operands, old_oplen + j, offset);
1191       }
1192 
1193       // replace target operands array with combined array
1194       to_cp->set_operands(new_operands);
1195     }
1196   }
1197 
1198 } // end copy_cp_to()
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(constantPoolHandle from_cp, int from_i,
1204                                         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   {
1285     // Can be resolved after checking tag, so check the slot first.
1286     CPSlot entry = from_cp->slot_at(from_i);
1287     if (entry.is_resolved()) {
1288       assert(entry.get_klass()->is_klass(), "must be");
1289       // Already resolved
1290       to_cp->klass_at_put(to_i, entry.get_klass());
1291     } else {
1292       to_cp->unresolved_klass_at_put(to_i, entry.get_symbol());
1293     }
1294   } break;
1295 
1296   case JVM_CONSTANT_UnresolvedClassInError:
1297   {
1298     Symbol* k = from_cp->unresolved_klass_at(from_i);
1299     to_cp->unresolved_klass_at_put(to_i, k);
1300     to_cp->tag_at_put(to_i, JVM_CONSTANT_UnresolvedClassInError);
1301   } break;
1302 
1303 
1304   case JVM_CONSTANT_String:
1305   {
1306     Symbol* s = from_cp->unresolved_string_at(from_i);
1307     to_cp->unresolved_string_at_put(to_i, s);
1308   } break;
1309 
1310   case JVM_CONSTANT_Utf8:
1311   {
1312     Symbol* s = from_cp->symbol_at(from_i);
1313     // Need to increase refcount, the old one will be thrown away and deferenced
1314     s->increment_refcount();
1315     to_cp->symbol_at_put(to_i, s);
1316   } break;
1317 
1318   case JVM_CONSTANT_MethodType:
1319   {
1320     jint k = from_cp->method_type_index_at(from_i);
1321     to_cp->method_type_index_at_put(to_i, k);
1322   } break;
1323 
1324   case JVM_CONSTANT_MethodHandle:
1325   {
1326     int k1 = from_cp->method_handle_ref_kind_at(from_i);
1327     int k2 = from_cp->method_handle_index_at(from_i);
1328     to_cp->method_handle_index_at_put(to_i, k1, k2);
1329   } break;
1330 
1331   case JVM_CONSTANT_InvokeDynamic:
1332   {
1333     int k1 = from_cp->invoke_dynamic_bootstrap_specifier_index(from_i);
1334     int k2 = from_cp->invoke_dynamic_name_and_type_ref_index_at(from_i);
1335     k1 += operand_array_length(to_cp->operands());  // to_cp might already have operands
1336     to_cp->invoke_dynamic_at_put(to_i, k1, k2);
1337   } break;
1338 
1339   // Invalid is used as the tag for the second constant pool entry
1340   // occupied by JVM_CONSTANT_Double or JVM_CONSTANT_Long. It should
1341   // not be seen by itself.
1342   case JVM_CONSTANT_Invalid: // fall through
1343 
1344   default:
1345   {
1346     ShouldNotReachHere();
1347   } break;
1348   }
1349 } // end copy_entry_to()
1350 
1351 
1352 // Search constant pool search_cp for an entry that matches this
1353 // constant pool's entry at pattern_i. Returns the index of a
1354 // matching entry or zero (0) if there is no matching entry.
1355 int ConstantPool::find_matching_entry(int pattern_i,
1356       constantPoolHandle search_cp, TRAPS) {
1357 
1358   // index zero (0) is not used
1359   for (int i = 1; i < search_cp->length(); i++) {
1360     bool found = compare_entry_to(pattern_i, search_cp, i, CHECK_0);
1361     if (found) {
1362       return i;
1363     }
1364   }
1365 
1366   return 0;  // entry not found; return unused index zero (0)
1367 } // end find_matching_entry()
1368 
1369 
1370 #ifndef PRODUCT
1371 
1372 const char* ConstantPool::printable_name_at(int which) {
1373 
1374   constantTag tag = tag_at(which);
1375 
1376   if (tag.is_string()) {
1377     return string_at_noresolve(which);
1378   } else if (tag.is_klass() || tag.is_unresolved_klass()) {
1379     return klass_name_at(which)->as_C_string();
1380   } else if (tag.is_symbol()) {
1381     return symbol_at(which)->as_C_string();
1382   }
1383   return "";
1384 }
1385 
1386 #endif // PRODUCT
1387 
1388 
1389 // JVMTI GetConstantPool support
1390 
1391 // For temporary use until code is stable.
1392 #if DEBUG_CPOOL
1393 #define DBG(code) code
1394 
1395 static const char* WARN_MSG = "Must not be such entry!";
1396 
1397 static void print_cpool_bytes(jint cnt, u1 *bytes) {
1398   jint size = 0;
1399   u2   idx1, idx2;
1400 
1401   for (jint idx = 1; idx < cnt; idx++) {
1402     jint ent_size = 0;
1403     u1   tag  = *bytes++;
1404     size++;                       // count tag
1405 
1406     printf("const #%03d, tag: %02d ", idx, tag);
1407     switch(tag) {
1408       case JVM_CONSTANT_Invalid: {
1409         printf("Invalid");
1410         break;
1411       }
1412       case JVM_CONSTANT_Unicode: {
1413         printf("Unicode      %s", WARN_MSG);
1414         break;
1415       }
1416       case JVM_CONSTANT_Utf8: {
1417         u2 len = Bytes::get_Java_u2(bytes);
1418         char str[128];
1419         if (len > 127) {
1420            len = 127;
1421         }
1422         strncpy(str, (char *) (bytes+2), len);
1423         str[len] = '\0';
1424         printf("Utf8          \"%s\"", str);
1425         ent_size = 2 + len;
1426         break;
1427       }
1428       case JVM_CONSTANT_Integer: {
1429         u4 val = Bytes::get_Java_u4(bytes);
1430         printf("int          %d", *(int *) &val);
1431         ent_size = 4;
1432         break;
1433       }
1434       case JVM_CONSTANT_Float: {
1435         u4 val = Bytes::get_Java_u4(bytes);
1436         printf("float        %5.3ff", *(float *) &val);
1437         ent_size = 4;
1438         break;
1439       }
1440       case JVM_CONSTANT_Long: {
1441         u8 val = Bytes::get_Java_u8(bytes);
1442         printf("long         "INT64_FORMAT, (int64_t) *(jlong *) &val);
1443         ent_size = 8;
1444         idx++; // Long takes two cpool slots
1445         break;
1446       }
1447       case JVM_CONSTANT_Double: {
1448         u8 val = Bytes::get_Java_u8(bytes);
1449         printf("double       %5.3fd", *(jdouble *)&val);
1450         ent_size = 8;
1451         idx++; // Double takes two cpool slots
1452         break;
1453       }
1454       case JVM_CONSTANT_Class: {
1455         idx1 = Bytes::get_Java_u2(bytes);
1456         printf("class        #%03d", idx1);
1457         ent_size = 2;
1458         break;
1459       }
1460       case JVM_CONSTANT_String: {
1461         idx1 = Bytes::get_Java_u2(bytes);
1462         printf("String       #%03d", idx1);
1463         ent_size = 2;
1464         break;
1465       }
1466       case JVM_CONSTANT_Fieldref: {
1467         idx1 = Bytes::get_Java_u2(bytes);
1468         idx2 = Bytes::get_Java_u2(bytes+2);
1469         printf("Field        #%03d, #%03d", (int) idx1, (int) idx2);
1470         ent_size = 4;
1471         break;
1472       }
1473       case JVM_CONSTANT_Methodref: {
1474         idx1 = Bytes::get_Java_u2(bytes);
1475         idx2 = Bytes::get_Java_u2(bytes+2);
1476         printf("Method       #%03d, #%03d", idx1, idx2);
1477         ent_size = 4;
1478         break;
1479       }
1480       case JVM_CONSTANT_InterfaceMethodref: {
1481         idx1 = Bytes::get_Java_u2(bytes);
1482         idx2 = Bytes::get_Java_u2(bytes+2);
1483         printf("InterfMethod #%03d, #%03d", idx1, idx2);
1484         ent_size = 4;
1485         break;
1486       }
1487       case JVM_CONSTANT_NameAndType: {
1488         idx1 = Bytes::get_Java_u2(bytes);
1489         idx2 = Bytes::get_Java_u2(bytes+2);
1490         printf("NameAndType  #%03d, #%03d", idx1, idx2);
1491         ent_size = 4;
1492         break;
1493       }
1494       case JVM_CONSTANT_ClassIndex: {
1495         printf("ClassIndex  %s", WARN_MSG);
1496         break;
1497       }
1498       case JVM_CONSTANT_UnresolvedClass: {
1499         printf("UnresolvedClass: %s", WARN_MSG);
1500         break;
1501       }
1502       case JVM_CONSTANT_UnresolvedClassInError: {
1503         printf("UnresolvedClassInErr: %s", WARN_MSG);
1504         break;
1505       }
1506       case JVM_CONSTANT_StringIndex: {
1507         printf("StringIndex: %s", WARN_MSG);
1508         break;
1509       }
1510     }
1511     printf(";\n");
1512     bytes += ent_size;
1513     size  += ent_size;
1514   }
1515   printf("Cpool size: %d\n", size);
1516   fflush(0);
1517   return;
1518 } /* end print_cpool_bytes */
1519 
1520 #else
1521 
1522 #define DBG(code)
1523 
1524 #endif
1525 
1526 
1527 // Returns size of constant pool entry.
1528 jint ConstantPool::cpool_entry_size(jint idx) {
1529   switch(tag_at(idx).value()) {
1530     case JVM_CONSTANT_Invalid:
1531     case JVM_CONSTANT_Unicode:
1532       return 1;
1533 
1534     case JVM_CONSTANT_Utf8:
1535       return 3 + symbol_at(idx)->utf8_length();
1536 
1537     case JVM_CONSTANT_Class:
1538     case JVM_CONSTANT_String:
1539     case JVM_CONSTANT_ClassIndex:
1540     case JVM_CONSTANT_UnresolvedClass:
1541     case JVM_CONSTANT_UnresolvedClassInError:
1542     case JVM_CONSTANT_StringIndex:
1543     case JVM_CONSTANT_MethodType:
1544       return 3;
1545 
1546     case JVM_CONSTANT_MethodHandle:
1547       return 4; //tag, ref_kind, ref_index
1548 
1549     case JVM_CONSTANT_Integer:
1550     case JVM_CONSTANT_Float:
1551     case JVM_CONSTANT_Fieldref:
1552     case JVM_CONSTANT_Methodref:
1553     case JVM_CONSTANT_InterfaceMethodref:
1554     case JVM_CONSTANT_NameAndType:
1555       return 5;
1556 
1557     case JVM_CONSTANT_InvokeDynamic:
1558       // u1 tag, u2 bsm, u2 nt
1559       return 5;
1560 
1561     case JVM_CONSTANT_Long:
1562     case JVM_CONSTANT_Double:
1563       return 9;
1564   }
1565   assert(false, "cpool_entry_size: Invalid constant pool entry tag");
1566   return 1;
1567 } /* end cpool_entry_size */
1568 
1569 
1570 // SymbolHashMap is used to find a constant pool index from a string.
1571 // This function fills in SymbolHashMaps, one for utf8s and one for
1572 // class names, returns size of the cpool raw bytes.
1573 jint ConstantPool::hash_entries_to(SymbolHashMap *symmap,
1574                                           SymbolHashMap *classmap) {
1575   jint size = 0;
1576 
1577   for (u2 idx = 1; idx < length(); idx++) {
1578     u2 tag = tag_at(idx).value();
1579     size += cpool_entry_size(idx);
1580 
1581     switch(tag) {
1582       case JVM_CONSTANT_Utf8: {
1583         Symbol* sym = symbol_at(idx);
1584         symmap->add_entry(sym, idx);
1585         DBG(printf("adding symbol entry %s = %d\n", sym->as_utf8(), idx));
1586         break;
1587       }
1588       case JVM_CONSTANT_Class:
1589       case JVM_CONSTANT_UnresolvedClass:
1590       case JVM_CONSTANT_UnresolvedClassInError: {
1591         Symbol* sym = klass_name_at(idx);
1592         classmap->add_entry(sym, idx);
1593         DBG(printf("adding class entry %s = %d\n", sym->as_utf8(), idx));
1594         break;
1595       }
1596       case JVM_CONSTANT_Long:
1597       case JVM_CONSTANT_Double: {
1598         idx++; // Both Long and Double take two cpool slots
1599         break;
1600       }
1601     }
1602   }
1603   return size;
1604 } /* end hash_utf8_entries_to */
1605 
1606 
1607 // Copy cpool bytes.
1608 // Returns:
1609 //    0, in case of OutOfMemoryError
1610 //   -1, in case of internal error
1611 //  > 0, count of the raw cpool bytes that have been copied
1612 int ConstantPool::copy_cpool_bytes(int cpool_size,
1613                                           SymbolHashMap* tbl,
1614                                           unsigned char *bytes) {
1615   u2   idx1, idx2;
1616   jint size  = 0;
1617   jint cnt   = length();
1618   unsigned char *start_bytes = bytes;
1619 
1620   for (jint idx = 1; idx < cnt; idx++) {
1621     u1   tag      = tag_at(idx).value();
1622     jint ent_size = cpool_entry_size(idx);
1623 
1624     assert(size + ent_size <= cpool_size, "Size mismatch");
1625 
1626     *bytes = tag;
1627     DBG(printf("#%03hd tag=%03hd, ", idx, tag));
1628     switch(tag) {
1629       case JVM_CONSTANT_Invalid: {
1630         DBG(printf("JVM_CONSTANT_Invalid"));
1631         break;
1632       }
1633       case JVM_CONSTANT_Unicode: {
1634         assert(false, "Wrong constant pool tag: JVM_CONSTANT_Unicode");
1635         DBG(printf("JVM_CONSTANT_Unicode"));
1636         break;
1637       }
1638       case JVM_CONSTANT_Utf8: {
1639         Symbol* sym = symbol_at(idx);
1640         char*     str = sym->as_utf8();
1641         // Warning! It's crashing on x86 with len = sym->utf8_length()
1642         int       len = (int) strlen(str);
1643         Bytes::put_Java_u2((address) (bytes+1), (u2) len);
1644         for (int i = 0; i < len; i++) {
1645             bytes[3+i] = (u1) str[i];
1646         }
1647         DBG(printf("JVM_CONSTANT_Utf8: %s ", str));
1648         break;
1649       }
1650       case JVM_CONSTANT_Integer: {
1651         jint val = int_at(idx);
1652         Bytes::put_Java_u4((address) (bytes+1), *(u4*)&val);
1653         break;
1654       }
1655       case JVM_CONSTANT_Float: {
1656         jfloat val = float_at(idx);
1657         Bytes::put_Java_u4((address) (bytes+1), *(u4*)&val);
1658         break;
1659       }
1660       case JVM_CONSTANT_Long: {
1661         jlong val = long_at(idx);
1662         Bytes::put_Java_u8((address) (bytes+1), *(u8*)&val);
1663         idx++;             // Long takes two cpool slots
1664         break;
1665       }
1666       case JVM_CONSTANT_Double: {
1667         jdouble val = double_at(idx);
1668         Bytes::put_Java_u8((address) (bytes+1), *(u8*)&val);
1669         idx++;             // Double takes two cpool slots
1670         break;
1671       }
1672       case JVM_CONSTANT_Class:
1673       case JVM_CONSTANT_UnresolvedClass:
1674       case JVM_CONSTANT_UnresolvedClassInError: {
1675         *bytes = JVM_CONSTANT_Class;
1676         Symbol* sym = klass_name_at(idx);
1677         idx1 = tbl->symbol_to_value(sym);
1678         assert(idx1 != 0, "Have not found a hashtable entry");
1679         Bytes::put_Java_u2((address) (bytes+1), idx1);
1680         DBG(printf("JVM_CONSTANT_Class: idx=#%03hd, %s", idx1, sym->as_utf8()));
1681         break;
1682       }
1683       case JVM_CONSTANT_String: {
1684         *bytes = JVM_CONSTANT_String;
1685         Symbol* sym = unresolved_string_at(idx);
1686         idx1 = tbl->symbol_to_value(sym);
1687         assert(idx1 != 0, "Have not found a hashtable entry");
1688         Bytes::put_Java_u2((address) (bytes+1), idx1);
1689         DBG(char *str = sym->as_utf8());
1690         DBG(printf("JVM_CONSTANT_String: idx=#%03hd, %s", idx1, str));
1691         break;
1692       }
1693       case JVM_CONSTANT_Fieldref:
1694       case JVM_CONSTANT_Methodref:
1695       case JVM_CONSTANT_InterfaceMethodref: {
1696         idx1 = uncached_klass_ref_index_at(idx);
1697         idx2 = uncached_name_and_type_ref_index_at(idx);
1698         Bytes::put_Java_u2((address) (bytes+1), idx1);
1699         Bytes::put_Java_u2((address) (bytes+3), idx2);
1700         DBG(printf("JVM_CONSTANT_Methodref: %hd %hd", idx1, idx2));
1701         break;
1702       }
1703       case JVM_CONSTANT_NameAndType: {
1704         idx1 = name_ref_index_at(idx);
1705         idx2 = signature_ref_index_at(idx);
1706         Bytes::put_Java_u2((address) (bytes+1), idx1);
1707         Bytes::put_Java_u2((address) (bytes+3), idx2);
1708         DBG(printf("JVM_CONSTANT_NameAndType: %hd %hd", idx1, idx2));
1709         break;
1710       }
1711       case JVM_CONSTANT_ClassIndex: {
1712         *bytes = JVM_CONSTANT_Class;
1713         idx1 = klass_index_at(idx);
1714         Bytes::put_Java_u2((address) (bytes+1), idx1);
1715         DBG(printf("JVM_CONSTANT_ClassIndex: %hd", idx1));
1716         break;
1717       }
1718       case JVM_CONSTANT_StringIndex: {
1719         *bytes = JVM_CONSTANT_String;
1720         idx1 = string_index_at(idx);
1721         Bytes::put_Java_u2((address) (bytes+1), idx1);
1722         DBG(printf("JVM_CONSTANT_StringIndex: %hd", idx1));
1723         break;
1724       }
1725       case JVM_CONSTANT_MethodHandle:
1726       case JVM_CONSTANT_MethodHandleInError: {
1727         *bytes = JVM_CONSTANT_MethodHandle;
1728         int kind = method_handle_ref_kind_at(idx);
1729         idx1 = method_handle_index_at(idx);
1730         *(bytes+1) = (unsigned char) kind;
1731         Bytes::put_Java_u2((address) (bytes+2), idx1);
1732         DBG(printf("JVM_CONSTANT_MethodHandle: %d %hd", kind, idx1));
1733         break;
1734       }
1735       case JVM_CONSTANT_MethodType:
1736       case JVM_CONSTANT_MethodTypeInError: {
1737         *bytes = JVM_CONSTANT_MethodType;
1738         idx1 = method_type_index_at(idx);
1739         Bytes::put_Java_u2((address) (bytes+1), idx1);
1740         DBG(printf("JVM_CONSTANT_MethodType: %hd", idx1));
1741         break;
1742       }
1743       case JVM_CONSTANT_InvokeDynamic: {
1744         *bytes = tag;
1745         idx1 = extract_low_short_from_int(*int_at_addr(idx));
1746         idx2 = extract_high_short_from_int(*int_at_addr(idx));
1747         assert(idx2 == invoke_dynamic_name_and_type_ref_index_at(idx), "correct half of u4");
1748         Bytes::put_Java_u2((address) (bytes+1), idx1);
1749         Bytes::put_Java_u2((address) (bytes+3), idx2);
1750         DBG(printf("JVM_CONSTANT_InvokeDynamic: %hd %hd", idx1, idx2));
1751         break;
1752       }
1753     }
1754     DBG(printf("\n"));
1755     bytes += ent_size;
1756     size  += ent_size;
1757   }
1758   assert(size == cpool_size, "Size mismatch");
1759 
1760   // Keep temorarily for debugging until it's stable.
1761   DBG(print_cpool_bytes(cnt, start_bytes));
1762   return (int)(bytes - start_bytes);
1763 } /* end copy_cpool_bytes */
1764 
1765 
1766 void ConstantPool::set_on_stack(const bool value) {
1767   _on_stack = value;
1768   if (value) MetadataOnStackMark::record(this);
1769 }
1770 
1771 // JSR 292 support for patching constant pool oops after the class is linked and
1772 // the oop array for resolved references are created.
1773 // We can't do this during classfile parsing, which is how the other indexes are
1774 // patched.  The other patches are applied early for some error checking
1775 // so only defer the pseudo_strings.
1776 void ConstantPool::patch_resolved_references(
1777                                             GrowableArray<Handle>* cp_patches) {
1778   assert(EnableInvokeDynamic, "");
1779   for (int index = 1; index < cp_patches->length(); index++) { // Index 0 is unused
1780     Handle patch = cp_patches->at(index);
1781     if (patch.not_null()) {
1782       assert (tag_at(index).is_string(), "should only be string left");
1783       // Patching a string means pre-resolving it.
1784       // The spelling in the constant pool is ignored.
1785       // The constant reference may be any object whatever.
1786       // If it is not a real interned string, the constant is referred
1787       // to as a "pseudo-string", and must be presented to the CP
1788       // explicitly, because it may require scavenging.
1789       int obj_index = cp_to_object_index(index);
1790       pseudo_string_at_put(index, obj_index, patch());
1791       DEBUG_ONLY(cp_patches->at_put(index, Handle());)
1792     }
1793   }
1794 #ifdef ASSERT
1795   // Ensure that all the patches have been used.
1796   for (int index = 0; index < cp_patches->length(); index++) {
1797     assert(cp_patches->at(index).is_null(),
1798            err_msg("Unused constant pool patch at %d in class file %s",
1799                    index,
1800                    pool_holder()->external_name()));
1801   }
1802 #endif // ASSERT
1803 }
1804 
1805 #ifndef PRODUCT
1806 
1807 // CompileTheWorld support. Preload all classes loaded references in the passed in constantpool
1808 void ConstantPool::preload_and_initialize_all_classes(ConstantPool* obj, TRAPS) {
1809   guarantee(obj->is_constantPool(), "object must be constant pool");
1810   constantPoolHandle cp(THREAD, (ConstantPool*)obj);
1811   guarantee(cp->pool_holder() != NULL, "must be fully loaded");
1812 
1813   for (int i = 0; i< cp->length();  i++) {
1814     if (cp->tag_at(i).is_unresolved_klass()) {
1815       // This will force loading of the class
1816       Klass* klass = cp->klass_at(i, CHECK);
1817       if (klass->oop_is_instance()) {
1818         // Force initialization of class
1819         InstanceKlass::cast(klass)->initialize(CHECK);
1820       }
1821     }
1822   }
1823 }
1824 
1825 #endif
1826 
1827 
1828 // Printing
1829 
1830 void ConstantPool::print_on(outputStream* st) const {
1831   EXCEPTION_MARK;
1832   assert(is_constantPool(), "must be constantPool");
1833   st->print_cr(internal_name());
1834   if (flags() != 0) {
1835     st->print(" - flags: 0x%x", flags());
1836     if (has_pseudo_string()) st->print(" has_pseudo_string");
1837     if (has_invokedynamic()) st->print(" has_invokedynamic");
1838     if (has_preresolution()) st->print(" has_preresolution");
1839     st->cr();
1840   }
1841   if (pool_holder() != NULL) {
1842     st->print_cr(" - holder: " INTPTR_FORMAT, pool_holder());
1843   }
1844   st->print_cr(" - cache: " INTPTR_FORMAT, cache());
1845   st->print_cr(" - resolved_references: " INTPTR_FORMAT, resolved_references());
1846   st->print_cr(" - reference_map: " INTPTR_FORMAT, reference_map());
1847 
1848   for (int index = 1; index < length(); index++) {      // Index 0 is unused
1849     ((ConstantPool*)this)->print_entry_on(index, st);
1850     switch (tag_at(index).value()) {
1851       case JVM_CONSTANT_Long :
1852       case JVM_CONSTANT_Double :
1853         index++;   // Skip entry following eigth-byte constant
1854     }
1855 
1856   }
1857   st->cr();
1858 }
1859 
1860 // Print one constant pool entry
1861 void ConstantPool::print_entry_on(const int index, outputStream* st) {
1862   EXCEPTION_MARK;
1863   st->print(" - %3d : ", index);
1864   tag_at(index).print_on(st);
1865   st->print(" : ");
1866   switch (tag_at(index).value()) {
1867     case JVM_CONSTANT_Class :
1868       { Klass* k = klass_at(index, CATCH);
1869         k->print_value_on(st);
1870         st->print(" {0x%lx}", (address)k);
1871       }
1872       break;
1873     case JVM_CONSTANT_Fieldref :
1874     case JVM_CONSTANT_Methodref :
1875     case JVM_CONSTANT_InterfaceMethodref :
1876       st->print("klass_index=%d", uncached_klass_ref_index_at(index));
1877       st->print(" name_and_type_index=%d", uncached_name_and_type_ref_index_at(index));
1878       break;
1879     case JVM_CONSTANT_String :
1880       unresolved_string_at(index)->print_value_on(st);
1881       break;
1882     case JVM_CONSTANT_Object : {
1883       oop anObj = object_at(index);
1884       anObj->print_value_on(st);
1885       st->print(" {0x%lx}", (address)anObj);
1886       } break;
1887     case JVM_CONSTANT_Integer :
1888       st->print("%d", int_at(index));
1889       break;
1890     case JVM_CONSTANT_Float :
1891       st->print("%f", float_at(index));
1892       break;
1893     case JVM_CONSTANT_Long :
1894       st->print_jlong(long_at(index));
1895       break;
1896     case JVM_CONSTANT_Double :
1897       st->print("%lf", double_at(index));
1898       break;
1899     case JVM_CONSTANT_NameAndType :
1900       st->print("name_index=%d", name_ref_index_at(index));
1901       st->print(" signature_index=%d", signature_ref_index_at(index));
1902       break;
1903     case JVM_CONSTANT_Utf8 :
1904       symbol_at(index)->print_value_on(st);
1905       break;
1906     case JVM_CONSTANT_UnresolvedClass :               // fall-through
1907     case JVM_CONSTANT_UnresolvedClassInError: {
1908       // unresolved_klass_at requires lock or safe world.
1909       CPSlot entry = slot_at(index);
1910       if (entry.is_resolved()) {
1911         entry.get_klass()->print_value_on(st);
1912       } else {
1913         entry.get_symbol()->print_value_on(st);
1914       }
1915       }
1916       break;
1917     case JVM_CONSTANT_MethodHandle :
1918     case JVM_CONSTANT_MethodHandleInError :
1919       st->print("ref_kind=%d", method_handle_ref_kind_at(index));
1920       st->print(" ref_index=%d", method_handle_index_at(index));
1921       break;
1922     case JVM_CONSTANT_MethodType :
1923     case JVM_CONSTANT_MethodTypeInError :
1924       st->print("signature_index=%d", method_type_index_at(index));
1925       break;
1926     case JVM_CONSTANT_InvokeDynamic :
1927       {
1928         st->print("bootstrap_method_index=%d", invoke_dynamic_bootstrap_method_ref_index_at(index));
1929         st->print(" name_and_type_index=%d", invoke_dynamic_name_and_type_ref_index_at(index));
1930         int argc = invoke_dynamic_argument_count_at(index);
1931         if (argc > 0) {
1932           for (int arg_i = 0; arg_i < argc; arg_i++) {
1933             int arg = invoke_dynamic_argument_index_at(index, arg_i);
1934             st->print((arg_i == 0 ? " arguments={%d" : ", %d"), arg);
1935           }
1936           st->print("}");
1937         }
1938       }
1939       break;
1940     default:
1941       ShouldNotReachHere();
1942       break;
1943   }
1944   st->cr();
1945 }
1946 
1947 void ConstantPool::print_value_on(outputStream* st) const {
1948   assert(is_constantPool(), "must be constantPool");
1949   st->print("constant pool [%d]", length());
1950   if (has_pseudo_string()) st->print("/pseudo_string");
1951   if (has_invokedynamic()) st->print("/invokedynamic");
1952   if (has_preresolution()) st->print("/preresolution");
1953   if (operands() != NULL)  st->print("/operands[%d]", operands()->length());
1954   print_address_on(st);
1955   st->print(" for ");
1956   pool_holder()->print_value_on(st);
1957   if (pool_holder() != NULL) {
1958     bool extra = (pool_holder()->constants() != this);
1959     if (extra)  st->print(" (extra)");
1960   }
1961   if (cache() != NULL) {
1962     st->print(" cache=" PTR_FORMAT, cache());
1963   }
1964 }
1965 
1966 
1967 // Verification
1968 
1969 void ConstantPool::verify_on(outputStream* st) {
1970   guarantee(is_constantPool(), "object must be constant pool");
1971   for (int i = 0; i< length();  i++) {
1972     constantTag tag = tag_at(i);
1973     CPSlot entry = slot_at(i);
1974     if (tag.is_klass()) {
1975       if (entry.is_resolved()) {
1976         guarantee(entry.get_klass()->is_metadata(), "should be metadata");
1977         guarantee(entry.get_klass()->is_klass(),    "should be klass");
1978       }
1979     } else if (tag.is_unresolved_klass()) {
1980       if (entry.is_resolved()) {
1981         guarantee(entry.get_klass()->is_metadata(), "should be metadata");
1982         guarantee(entry.get_klass()->is_klass(),    "should be klass");
1983       }
1984     } else if (tag.is_symbol()) {
1985       guarantee(entry.get_symbol()->refcount() != 0, "should have nonzero reference count");
1986     } else if (tag.is_string()) {
1987       guarantee(entry.get_symbol()->refcount() != 0, "should have nonzero reference count");
1988     }
1989   }
1990   if (cache() != NULL) {
1991     // Note: cache() can be NULL before a class is completely setup or
1992     // in temporary constant pools used during constant pool merging
1993     guarantee(cache()->is_metadata(),          "should be metadata");
1994     guarantee(cache()->is_constantPoolCache(), "should be constant pool cache");
1995   }
1996   if (pool_holder() != NULL) {
1997     // Note: pool_holder() can be NULL in temporary constant pools
1998     // used during constant pool merging
1999     guarantee(pool_holder()->is_metadata(), "should be metadata");
2000     guarantee(pool_holder()->is_klass(),    "should be klass");
2001   }
2002 }
2003 
2004 
2005 void SymbolHashMap::add_entry(Symbol* sym, u2 value) {
2006   char *str = sym->as_utf8();
2007   unsigned int hash = compute_hash(str, sym->utf8_length());
2008   unsigned int index = hash % table_size();
2009 
2010   // check if already in map
2011   // we prefer the first entry since it is more likely to be what was used in
2012   // the class file
2013   for (SymbolHashMapEntry *en = bucket(index); en != NULL; en = en->next()) {
2014     assert(en->symbol() != NULL, "SymbolHashMapEntry symbol is NULL");
2015     if (en->hash() == hash && en->symbol() == sym) {
2016         return;  // already there
2017     }
2018   }
2019 
2020   SymbolHashMapEntry* entry = new SymbolHashMapEntry(hash, sym, value);
2021   entry->set_next(bucket(index));
2022   _buckets[index].set_entry(entry);
2023   assert(entry->symbol() != NULL, "SymbolHashMapEntry symbol is NULL");
2024 }
2025 
2026 SymbolHashMapEntry* SymbolHashMap::find_entry(Symbol* sym) {
2027   assert(sym != NULL, "SymbolHashMap::find_entry - symbol is NULL");
2028   char *str = sym->as_utf8();
2029   int   len = sym->utf8_length();
2030   unsigned int hash = SymbolHashMap::compute_hash(str, len);
2031   unsigned int index = hash % table_size();
2032   for (SymbolHashMapEntry *en = bucket(index); en != NULL; en = en->next()) {
2033     assert(en->symbol() != NULL, "SymbolHashMapEntry symbol is NULL");
2034     if (en->hash() == hash && en->symbol() == sym) {
2035       return en;
2036     }
2037   }
2038   return NULL;
2039 }