1 /*
   2  * Copyright (c) 1997, 2018, 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 "jvm.h"
  27 #include "classfile/classLoaderData.hpp"
  28 #include "classfile/javaClasses.inline.hpp"
  29 #include "classfile/metadataOnStackMark.hpp"
  30 #include "classfile/stringTable.hpp"
  31 #include "classfile/systemDictionary.hpp"
  32 #include "classfile/vmSymbols.hpp"
  33 #include "interpreter/linkResolver.hpp"
  34 #include "memory/allocation.inline.hpp"
  35 #include "memory/heapInspection.hpp"
  36 #include "memory/metadataFactory.hpp"
  37 #include "memory/metaspaceClosure.hpp"
  38 #include "memory/metaspaceShared.hpp"
  39 #include "memory/oopFactory.hpp"
  40 #include "memory/resourceArea.hpp"
  41 #include "oops/constantPool.hpp"
  42 #include "oops/instanceKlass.hpp"
  43 #include "oops/objArrayKlass.hpp"
  44 #include "oops/objArrayOop.inline.hpp"
  45 #include "oops/oop.inline.hpp"
  46 #include "runtime/fieldType.hpp"
  47 #include "runtime/init.hpp"
  48 #include "runtime/javaCalls.hpp"
  49 #include "runtime/signature.hpp"
  50 #include "runtime/vframe.hpp"
  51 #include "utilities/copy.hpp"
  52 
  53 ConstantPool* ConstantPool::allocate(ClassLoaderData* loader_data, int length, TRAPS) {
  54   Array<u1>* tags = MetadataFactory::new_array<u1>(loader_data, length, 0, CHECK_NULL);
  55   int size = ConstantPool::size(length);
  56   return new (loader_data, size, MetaspaceObj::ConstantPoolType, THREAD) ConstantPool(tags);
  57 }
  58 
  59 #ifdef ASSERT
  60 
  61 // MetaspaceObj allocation invariant is calloc equivalent memory
  62 // simple verification of this here (JVM_CONSTANT_Invalid == 0 )
  63 static bool tag_array_is_zero_initialized(Array<u1>* tags) {
  64   assert(tags != NULL, "invariant");
  65   const int length = tags->length();
  66   for (int index = 0; index < length; ++index) {
  67     if (JVM_CONSTANT_Invalid != tags->at(index)) {
  68       return false;
  69     }
  70   }
  71   return true;
  72 }
  73 
  74 #endif
  75 
  76 ConstantPool::ConstantPool(Array<u1>* tags) :
  77   _tags(tags),
  78   _length(tags->length()) {
  79 
  80     assert(_tags != NULL, "invariant");
  81     assert(tags->length() == _length, "invariant");
  82     assert(tag_array_is_zero_initialized(tags), "invariant");
  83     assert(0 == flags(), "invariant");
  84     assert(0 == version(), "invariant");
  85     assert(NULL == _pool_holder, "invariant");
  86 }
  87 
  88 void ConstantPool::deallocate_contents(ClassLoaderData* loader_data) {
  89   if (cache() != NULL) {
  90     MetadataFactory::free_metadata(loader_data, cache());
  91     set_cache(NULL);
  92   }
  93 
  94   MetadataFactory::free_array<Klass*>(loader_data, resolved_klasses());
  95   set_resolved_klasses(NULL);
  96 
  97   MetadataFactory::free_array<jushort>(loader_data, operands());
  98   set_operands(NULL);
  99 
 100   release_C_heap_structures();
 101 
 102   // free tag array
 103   MetadataFactory::free_array<u1>(loader_data, tags());
 104   set_tags(NULL);
 105 }
 106 
 107 void ConstantPool::release_C_heap_structures() {
 108   // walk constant pool and decrement symbol reference counts
 109   unreference_symbols();
 110 }
 111 
 112 void ConstantPool::metaspace_pointers_do(MetaspaceClosure* it) {
 113   log_trace(cds)("Iter(ConstantPool): %p", this);
 114 
 115   it->push(&_tags, MetaspaceClosure::_writable);
 116   it->push(&_cache);
 117   it->push(&_pool_holder);
 118   it->push(&_operands);
 119   it->push(&_resolved_klasses, MetaspaceClosure::_writable);
 120 
 121   for (int i = 0; i < length(); i++) {
 122     // The only MSO's embedded in the CP entries are Symbols:
 123     //   JVM_CONSTANT_String (normal and pseudo)
 124     //   JVM_CONSTANT_Utf8
 125     constantTag ctag = tag_at(i);
 126     if (ctag.is_string() || ctag.is_utf8()) {
 127       it->push(symbol_at_addr(i));
 128     }
 129   }
 130 }
 131 
 132 objArrayOop ConstantPool::resolved_references() const {
 133   return (objArrayOop)_cache->resolved_references();
 134 }
 135 
 136 // Called from outside constant pool resolution where a resolved_reference array
 137 // may not be present.
 138 objArrayOop ConstantPool::resolved_references_or_null() const {
 139   if (_cache == NULL) {
 140     return NULL;
 141   } else {
 142     return (objArrayOop)_cache->resolved_references();
 143   }
 144 }
 145 
 146 // Create resolved_references array and mapping array for original cp indexes
 147 // The ldc bytecode was rewritten to have the resolved reference array index so need a way
 148 // to map it back for resolving and some unlikely miscellaneous uses.
 149 // The objects created by invokedynamic are appended to this list.
 150 void ConstantPool::initialize_resolved_references(ClassLoaderData* loader_data,
 151                                                   const intStack& reference_map,
 152                                                   int constant_pool_map_length,
 153                                                   TRAPS) {
 154   // Initialized the resolved object cache.
 155   int map_length = reference_map.length();
 156   if (map_length > 0) {
 157     // Only need mapping back to constant pool entries.  The map isn't used for
 158     // invokedynamic resolved_reference entries.  For invokedynamic entries,
 159     // the constant pool cache index has the mapping back to both the constant
 160     // pool and to the resolved reference index.
 161     if (constant_pool_map_length > 0) {
 162       Array<u2>* om = MetadataFactory::new_array<u2>(loader_data, constant_pool_map_length, CHECK);
 163 
 164       for (int i = 0; i < constant_pool_map_length; i++) {
 165         int x = reference_map.at(i);
 166         assert(x == (int)(jushort) x, "klass index is too big");
 167         om->at_put(i, (jushort)x);
 168       }
 169       set_reference_map(om);
 170     }
 171 
 172     // Create Java array for holding resolved strings, methodHandles,
 173     // methodTypes, invokedynamic and invokehandle appendix objects, etc.
 174     objArrayOop stom = oopFactory::new_objArray(SystemDictionary::Object_klass(), map_length, CHECK);
 175     Handle refs_handle (THREAD, (oop)stom);  // must handleize.
 176     set_resolved_references(loader_data->add_handle(refs_handle));
 177   }
 178 }
 179 
 180 void ConstantPool::allocate_resolved_klasses(ClassLoaderData* loader_data, int num_klasses, TRAPS) {
 181   // A ConstantPool can't possibly have 0xffff valid class entries,
 182   // because entry #0 must be CONSTANT_Invalid, and each class entry must refer to a UTF8
 183   // entry for the class's name. So at most we will have 0xfffe class entries.
 184   // This allows us to use 0xffff (ConstantPool::_temp_resolved_klass_index) to indicate
 185   // UnresolvedKlass entries that are temporarily created during class redefinition.
 186   assert(num_klasses < CPKlassSlot::_temp_resolved_klass_index, "sanity");
 187   assert(resolved_klasses() == NULL, "sanity");
 188   Array<Klass*>* rk = MetadataFactory::new_array<Klass*>(loader_data, num_klasses, CHECK);
 189   set_resolved_klasses(rk);
 190 }
 191 
 192 void ConstantPool::initialize_unresolved_klasses(ClassLoaderData* loader_data, TRAPS) {
 193   int len = length();
 194   int num_klasses = 0;
 195   for (int i = 1; i <len; i++) {
 196     switch (tag_at(i).value()) {
 197     case JVM_CONSTANT_ClassIndex:
 198       {
 199         const int class_index = klass_index_at(i);
 200         unresolved_klass_at_put(i, class_index, num_klasses++);
 201       }
 202       break;
 203     case JVM_CONSTANT_ValueIndex:
 204       {
 205         const int class_index = value_type_index_at(i);
 206         unresolved_value_type_at_put(i, class_index, num_klasses++);
 207       }
 208       break;
 209 #ifndef PRODUCT
 210     case JVM_CONSTANT_Class:
 211     case JVM_CONSTANT_UnresolvedClass:
 212     case JVM_CONSTANT_UnresolvedClassInError:
 213     case JVM_CONSTANT_Value:
 214     case JVM_CONSTANT_UnresolvedValue:
 215     case JVM_CONSTANT_UnresolvedValueInError:
 216       // All of these should have been reverted back to Unresolved before calling
 217       // this function.
 218       ShouldNotReachHere();
 219 #endif
 220     }
 221   }
 222   allocate_resolved_klasses(loader_data, num_klasses, THREAD);
 223 }
 224 
 225 // Anonymous class support:
 226 void ConstantPool::klass_at_put(int class_index, int name_index, int resolved_klass_index, Klass* k, Symbol* name) {
 227   assert(is_within_bounds(class_index), "index out of bounds");
 228   assert(is_within_bounds(name_index), "index out of bounds");
 229   assert((resolved_klass_index & 0xffff0000) == 0, "must be");
 230   *int_at_addr(class_index) =
 231     build_int_from_shorts((jushort)resolved_klass_index, (jushort)name_index);
 232 
 233   symbol_at_put(name_index, name);
 234   name->increment_refcount();
 235   Klass** adr = resolved_klasses()->adr_at(resolved_klass_index);
 236   OrderAccess::release_store(adr, k);
 237 
 238   // The interpreter assumes when the tag is stored, the klass is resolved
 239   // and the Klass* non-NULL, so we need hardware store ordering here.
 240   if (k != NULL) {
 241     release_tag_at_put(class_index, (k->is_value() ? (jbyte)JVM_CONSTANT_Value : JVM_CONSTANT_Class));
 242   } else {
 243     release_tag_at_put(class_index, (tag_at(class_index).is_value_type_or_reference() ?
 244                                        JVM_CONSTANT_UnresolvedValue : JVM_CONSTANT_UnresolvedClass));
 245   }
 246 }
 247 
 248 // Anonymous class support:
 249 void ConstantPool::klass_at_put(int class_index, Klass* k) {
 250   assert(k != NULL, "must be valid klass");
 251   CPKlassSlot kslot = klass_slot_at(class_index);
 252   int resolved_klass_index = kslot.resolved_klass_index();
 253   Klass** adr = resolved_klasses()->adr_at(resolved_klass_index);
 254   OrderAccess::release_store(adr, k);
 255 
 256   // The interpreter assumes when the tag is stored, the klass is resolved
 257   // and the Klass* non-NULL, so we need hardware store ordering here.
 258   release_tag_at_put(class_index, (k->is_value() ? (jbyte)JVM_CONSTANT_Value : JVM_CONSTANT_Class));
 259 }
 260 
 261 #if INCLUDE_CDS_JAVA_HEAP
 262 // Archive the resolved references
 263 void ConstantPool::archive_resolved_references(Thread* THREAD) {
 264   if (_cache == NULL) {
 265     return; // nothing to do
 266   }
 267 
 268   InstanceKlass *ik = pool_holder();
 269   if (!(ik->is_shared_boot_class() || ik->is_shared_platform_class() ||
 270         ik->is_shared_app_class())) {
 271     // Archiving resolved references for classes from non-builtin loaders
 272     // is not yet supported.
 273     set_resolved_references(NULL);
 274     return;
 275   }
 276 
 277   objArrayOop rr = resolved_references();
 278   Array<u2>* ref_map = reference_map();
 279   if (rr != NULL) {
 280     int ref_map_len = ref_map == NULL ? 0 : ref_map->length();
 281     int rr_len = rr->length();
 282     for (int i = 0; i < rr_len; i++) {
 283       oop p = rr->obj_at(i);
 284       rr->obj_at_put(i, NULL);
 285       if (p != NULL && i < ref_map_len) {
 286         int index = object_to_cp_index(i);
 287         // Skip the entry if the string hash code is 0 since the string
 288         // is not included in the shared string_table, see StringTable::copy_shared_string.
 289         if (tag_at(index).is_string() && java_lang_String::hash_code(p) != 0) {
 290           oop op = StringTable::create_archived_string(p, THREAD);
 291           // If the String object is not archived (possibly too large),
 292           // NULL is returned. Also set it in the array, so we won't
 293           // have a 'bad' reference in the archived resolved_reference
 294           // array.
 295           rr->obj_at_put(i, op);
 296         }
 297       }
 298     }
 299 
 300     oop archived = MetaspaceShared::archive_heap_object(rr, THREAD);
 301     _cache->set_archived_references(archived);
 302     set_resolved_references(NULL);
 303   }
 304 }
 305 
 306 void ConstantPool::resolve_class_constants(TRAPS) {
 307   assert(DumpSharedSpaces, "used during dump time only");
 308   // The _cache may be NULL if the _pool_holder klass fails verification
 309   // at dump time due to missing dependencies.
 310   if (cache() == NULL || reference_map() == NULL) {
 311     return; // nothing to do
 312   }
 313 
 314   constantPoolHandle cp(THREAD, this);
 315   for (int index = 1; index < length(); index++) { // Index 0 is unused
 316     if (tag_at(index).is_string() && !cp->is_pseudo_string_at(index)) {
 317       int cache_index = cp->cp_to_object_index(index);
 318       string_at_impl(cp, index, cache_index, CHECK);
 319     }
 320   }
 321 }
 322 #endif
 323 
 324 // CDS support. Create a new resolved_references array.
 325 void ConstantPool::restore_unshareable_info(TRAPS) {
 326   assert(is_constantPool(), "ensure C++ vtable is restored");
 327   assert(on_stack(), "should always be set for shared constant pools");
 328   assert(is_shared(), "should always be set for shared constant pools");
 329   assert(_cache != NULL, "constant pool _cache should not be NULL");
 330 
 331   // Only create the new resolved references array if it hasn't been attempted before
 332   if (resolved_references() != NULL) return;
 333 
 334   // restore the C++ vtable from the shared archive
 335   restore_vtable();
 336 
 337   if (SystemDictionary::Object_klass_loaded()) {
 338     ClassLoaderData* loader_data = pool_holder()->class_loader_data();
 339 #if INCLUDE_CDS_JAVA_HEAP
 340     if (MetaspaceShared::open_archive_heap_region_mapped() &&
 341         _cache->archived_references() != NULL) {
 342       oop archived = _cache->archived_references();
 343       // Create handle for the archived resolved reference array object
 344       Handle refs_handle(THREAD, archived);
 345       set_resolved_references(loader_data->add_handle(refs_handle));
 346     } else
 347 #endif
 348     {
 349       // No mapped archived resolved reference array
 350       // Recreate the object array and add to ClassLoaderData.
 351       int map_length = resolved_reference_length();
 352       if (map_length > 0) {
 353         objArrayOop stom = oopFactory::new_objArray(SystemDictionary::Object_klass(), map_length, CHECK);
 354         Handle refs_handle(THREAD, (oop)stom);  // must handleize.
 355         set_resolved_references(loader_data->add_handle(refs_handle));
 356       }
 357     }
 358   }
 359 }
 360 
 361 void ConstantPool::remove_unshareable_info() {
 362   // Resolved references are not in the shared archive.
 363   // Save the length for restoration.  It is not necessarily the same length
 364   // as reference_map.length() if invokedynamic is saved. It is needed when
 365   // re-creating the resolved reference array if archived heap data cannot be map
 366   // at runtime.
 367   set_resolved_reference_length(
 368     resolved_references() != NULL ? resolved_references()->length() : 0);
 369 
 370   // If archiving heap objects is not allowed, clear the resolved references.
 371   // Otherwise, it is cleared after the resolved references array is cached
 372   // (see archive_resolved_references()).
 373   if (!MetaspaceShared::is_heap_object_archiving_allowed()) {
 374     set_resolved_references(NULL);
 375   }
 376 
 377   // Shared ConstantPools are in the RO region, so the _flags cannot be modified.
 378   // The _on_stack flag is used to prevent ConstantPools from deallocation during
 379   // class redefinition. Since shared ConstantPools cannot be deallocated anyway,
 380   // we always set _on_stack to true to avoid having to change _flags during runtime.
 381   _flags |= (_on_stack | _is_shared);
 382   int num_klasses = 0;
 383   for (int index = 1; index < length(); index++) { // Index 0 is unused
 384     assert(!tag_at(index).is_unresolved_klass_in_error(), "This must not happen during dump time");
 385     if (tag_at(index).is_klass()) {
 386       // This class was resolved as a side effect of executing Java code
 387       // during dump time. We need to restore it back to an UnresolvedClass,
 388       // so that the proper class loading and initialization can happen
 389       // at runtime.
 390       CPKlassSlot kslot = klass_slot_at(index);
 391       int resolved_klass_index = kslot.resolved_klass_index();
 392       int name_index = kslot.name_index();
 393       assert(tag_at(name_index).is_symbol(), "sanity");
 394       resolved_klasses()->at_put(resolved_klass_index, NULL);
 395       tag_at_put(index, JVM_CONSTANT_UnresolvedClass);
 396       assert(klass_name_at(index) == symbol_at(name_index), "sanity");
 397     }
 398   }
 399   if (cache() != NULL) {
 400     cache()->remove_unshareable_info();
 401   }
 402 }
 403 
 404 int ConstantPool::cp_to_object_index(int cp_index) {
 405   // this is harder don't do this so much.
 406   int i = reference_map()->find(cp_index);
 407   // We might not find the index for jsr292 call.
 408   return (i < 0) ? _no_index_sentinel : i;
 409 }
 410 
 411 void ConstantPool::string_at_put(int which, int obj_index, oop str) {
 412   resolved_references()->obj_at_put(obj_index, str);
 413 }
 414 
 415 void ConstantPool::trace_class_resolution(const constantPoolHandle& this_cp, Klass* k) {
 416   ResourceMark rm;
 417   int line_number = -1;
 418   const char * source_file = NULL;
 419   if (JavaThread::current()->has_last_Java_frame()) {
 420     // try to identify the method which called this function.
 421     vframeStream vfst(JavaThread::current());
 422     if (!vfst.at_end()) {
 423       line_number = vfst.method()->line_number_from_bci(vfst.bci());
 424       Symbol* s = vfst.method()->method_holder()->source_file_name();
 425       if (s != NULL) {
 426         source_file = s->as_C_string();
 427       }
 428     }
 429   }
 430   if (k != this_cp->pool_holder()) {
 431     // only print something if the classes are different
 432     if (source_file != NULL) {
 433       log_debug(class, resolve)("%s %s %s:%d",
 434                  this_cp->pool_holder()->external_name(),
 435                  k->external_name(), source_file, line_number);
 436     } else {
 437       log_debug(class, resolve)("%s %s",
 438                  this_cp->pool_holder()->external_name(),
 439                  k->external_name());
 440     }
 441   }
 442 }
 443 
 444 Klass* ConstantPool::klass_at_impl(const constantPoolHandle& this_cp, int which,
 445                                    bool save_resolution_error, TRAPS) {
 446   assert(THREAD->is_Java_thread(), "must be a Java thread");
 447 
 448   // A resolved constantPool entry will contain a Klass*, otherwise a Symbol*.
 449   // It is not safe to rely on the tag bit's here, since we don't have a lock, and
 450   // the entry and tag is not updated atomicly.
 451   CPKlassSlot kslot = this_cp->klass_slot_at(which);
 452   int resolved_klass_index = kslot.resolved_klass_index();
 453   int name_index = kslot.name_index();
 454   assert(this_cp->tag_at(name_index).is_symbol(), "sanity");
 455 
 456   Klass* klass = this_cp->resolved_klasses()->at(resolved_klass_index);
 457 
 458   if (klass != NULL) {
 459     return klass;
 460   }
 461 
 462   // This tag doesn't change back to unresolved class unless at a safepoint.
 463   if (this_cp->tag_at(which).is_unresolved_klass_in_error() ||
 464       this_cp->tag_at(which).is_unresolved_value_type_in_error()) {
 465     // The original attempt to resolve this constant pool entry failed so find the
 466     // class of the original error and throw another error of the same class
 467     // (JVMS 5.4.3).
 468     // If there is a detail message, pass that detail message to the error.
 469     // The JVMS does not strictly require us to duplicate the same detail message,
 470     // or any internal exception fields such as cause or stacktrace.  But since the
 471     // detail message is often a class name or other literal string, we will repeat it
 472     // if we can find it in the symbol table.
 473     throw_resolution_error(this_cp, which, CHECK_0);
 474     ShouldNotReachHere();
 475   }
 476 
 477   Handle mirror_handle;
 478   Symbol* name = this_cp->symbol_at(name_index);
 479   Handle loader (THREAD, this_cp->pool_holder()->class_loader());
 480   Handle protection_domain (THREAD, this_cp->pool_holder()->protection_domain());
 481   Klass* k = SystemDictionary::resolve_or_fail(name, loader, protection_domain, true, THREAD);
 482   if (!HAS_PENDING_EXCEPTION) {
 483     // preserve the resolved klass from unloading
 484     mirror_handle = Handle(THREAD, k->java_mirror());
 485     // Do access check for klasses
 486     verify_constant_pool_resolve(this_cp, k, THREAD);
 487   }
 488 
 489   // Failed to resolve class. We must record the errors so that subsequent attempts
 490   // to resolve this constant pool entry fail with the same error (JVMS 5.4.3).
 491   if (HAS_PENDING_EXCEPTION) {
 492     if (save_resolution_error) {
 493       bool is_value_type_tag = this_cp->tag_at(which).is_value_type_or_reference();
 494       save_and_throw_exception(this_cp, which,
 495                                constantTag((is_value_type_tag ? JVM_CONSTANT_UnresolvedValue : JVM_CONSTANT_UnresolvedClass)),
 496                                CHECK_NULL);
 497       // If CHECK_NULL above doesn't return the exception, that means that
 498       // some other thread has beaten us and has resolved the class.
 499       // To preserve old behavior, we return the resolved class.
 500       klass = this_cp->resolved_klasses()->at(resolved_klass_index);
 501       assert(klass != NULL, "must be resolved if exception was cleared");
 502       return klass;
 503     } else {
 504       return NULL;  // return the pending exception
 505     }
 506   }
 507 
 508   // Make this class loader depend upon the class loader owning the class reference
 509   ClassLoaderData* this_key = this_cp->pool_holder()->class_loader_data();
 510   this_key->record_dependency(k, CHECK_NULL); // Can throw OOM
 511 
 512   // logging for class+resolve.
 513   if (log_is_enabled(Debug, class, resolve)){
 514     trace_class_resolution(this_cp, k);
 515   }
 516   Klass** adr = this_cp->resolved_klasses()->adr_at(resolved_klass_index);
 517   OrderAccess::release_store(adr, k);
 518   // The interpreter assumes when the tag is stored, the klass is resolved
 519   // and the Klass* stored in _resolved_klasses is non-NULL, so we need
 520   // hardware store ordering here.
 521   this_cp->release_tag_at_put(which, (k->is_value() ? (jbyte)JVM_CONSTANT_Value : JVM_CONSTANT_Class));
 522   return k;
 523 }
 524 
 525 
 526 // Does not update ConstantPool* - to avoid any exception throwing. Used
 527 // by compiler and exception handling.  Also used to avoid classloads for
 528 // instanceof operations. Returns NULL if the class has not been loaded or
 529 // if the verification of constant pool failed
 530 Klass* ConstantPool::klass_at_if_loaded(const constantPoolHandle& this_cp, int which) {
 531   CPKlassSlot kslot = this_cp->klass_slot_at(which);
 532   int resolved_klass_index = kslot.resolved_klass_index();
 533   int name_index = kslot.name_index();
 534   assert(this_cp->tag_at(name_index).is_symbol(), "sanity");
 535 
 536   Klass* k = this_cp->resolved_klasses()->at(resolved_klass_index);
 537   if (k != NULL) {
 538     return k;
 539   } else {
 540     Thread *thread = Thread::current();
 541     Symbol* name = this_cp->symbol_at(name_index);
 542     oop loader = this_cp->pool_holder()->class_loader();
 543     oop protection_domain = this_cp->pool_holder()->protection_domain();
 544     Handle h_prot (thread, protection_domain);
 545     Handle h_loader (thread, loader);
 546     Klass* k = SystemDictionary::find(name, h_loader, h_prot, thread);
 547 
 548     if (k != NULL) {
 549       // Make sure that resolving is legal
 550       EXCEPTION_MARK;
 551       // return NULL if verification fails
 552       verify_constant_pool_resolve(this_cp, k, THREAD);
 553       if (HAS_PENDING_EXCEPTION) {
 554         CLEAR_PENDING_EXCEPTION;
 555         return NULL;
 556       }
 557       return k;
 558     } else {
 559       return k;
 560     }
 561   }
 562 }
 563 
 564 
 565 Klass* ConstantPool::klass_ref_at_if_loaded(const constantPoolHandle& this_cp, int which) {
 566   return klass_at_if_loaded(this_cp, this_cp->klass_ref_index_at(which));
 567 }
 568 
 569 
 570 Method* ConstantPool::method_at_if_loaded(const constantPoolHandle& cpool,
 571                                                    int which) {
 572   if (cpool->cache() == NULL)  return NULL;  // nothing to load yet
 573   int cache_index = decode_cpcache_index(which, true);
 574   if (!(cache_index >= 0 && cache_index < cpool->cache()->length())) {
 575     // FIXME: should be an assert
 576     log_debug(class, resolve)("bad operand %d in:", which); cpool->print();
 577     return NULL;
 578   }
 579   ConstantPoolCacheEntry* e = cpool->cache()->entry_at(cache_index);
 580   return e->method_if_resolved(cpool);
 581 }
 582 
 583 
 584 bool ConstantPool::has_appendix_at_if_loaded(const constantPoolHandle& cpool, int which) {
 585   if (cpool->cache() == NULL)  return false;  // nothing to load yet
 586   int cache_index = decode_cpcache_index(which, true);
 587   ConstantPoolCacheEntry* e = cpool->cache()->entry_at(cache_index);
 588   return e->has_appendix();
 589 }
 590 
 591 oop ConstantPool::appendix_at_if_loaded(const constantPoolHandle& cpool, int which) {
 592   if (cpool->cache() == NULL)  return NULL;  // nothing to load yet
 593   int cache_index = decode_cpcache_index(which, true);
 594   ConstantPoolCacheEntry* e = cpool->cache()->entry_at(cache_index);
 595   return e->appendix_if_resolved(cpool);
 596 }
 597 
 598 
 599 bool ConstantPool::has_method_type_at_if_loaded(const constantPoolHandle& cpool, int which) {
 600   if (cpool->cache() == NULL)  return false;  // nothing to load yet
 601   int cache_index = decode_cpcache_index(which, true);
 602   ConstantPoolCacheEntry* e = cpool->cache()->entry_at(cache_index);
 603   return e->has_method_type();
 604 }
 605 
 606 oop ConstantPool::method_type_at_if_loaded(const constantPoolHandle& cpool, int which) {
 607   if (cpool->cache() == NULL)  return NULL;  // nothing to load yet
 608   int cache_index = decode_cpcache_index(which, true);
 609   ConstantPoolCacheEntry* e = cpool->cache()->entry_at(cache_index);
 610   return e->method_type_if_resolved(cpool);
 611 }
 612 
 613 
 614 Symbol* ConstantPool::impl_name_ref_at(int which, bool uncached) {
 615   int name_index = name_ref_index_at(impl_name_and_type_ref_index_at(which, uncached));
 616   return symbol_at(name_index);
 617 }
 618 
 619 
 620 Symbol* ConstantPool::impl_signature_ref_at(int which, bool uncached) {
 621   int signature_index = signature_ref_index_at(impl_name_and_type_ref_index_at(which, uncached));
 622   return symbol_at(signature_index);
 623 }
 624 
 625 int ConstantPool::impl_name_and_type_ref_index_at(int which, bool uncached) {
 626   int i = which;
 627   if (!uncached && cache() != NULL) {
 628     if (ConstantPool::is_invokedynamic_index(which)) {
 629       // Invokedynamic index is index into the constant pool cache
 630       int pool_index = invokedynamic_cp_cache_entry_at(which)->constant_pool_index();
 631       pool_index = invoke_dynamic_name_and_type_ref_index_at(pool_index);
 632       assert(tag_at(pool_index).is_name_and_type(), "");
 633       return pool_index;
 634     }
 635     // change byte-ordering and go via cache
 636     i = remap_instruction_operand_from_cache(which);
 637   } else {
 638     if (tag_at(which).is_invoke_dynamic() ||
 639         tag_at(which).is_dynamic_constant() ||
 640         tag_at(which).is_dynamic_constant_in_error()) {
 641       int pool_index = invoke_dynamic_name_and_type_ref_index_at(which);
 642       assert(tag_at(pool_index).is_name_and_type(), "");
 643       return pool_index;
 644     }
 645   }
 646   assert(tag_at(i).is_field_or_method(), "Corrupted constant pool");
 647   assert(!tag_at(i).is_invoke_dynamic() &&
 648          !tag_at(i).is_dynamic_constant() &&
 649          !tag_at(i).is_dynamic_constant_in_error(), "Must be handled above");
 650   jint ref_index = *int_at_addr(i);
 651   return extract_high_short_from_int(ref_index);
 652 }
 653 
 654 constantTag ConstantPool::impl_tag_ref_at(int which, bool uncached) {
 655   int pool_index = which;
 656   if (!uncached && cache() != NULL) {
 657     if (ConstantPool::is_invokedynamic_index(which)) {
 658       // Invokedynamic index is index into resolved_references
 659       pool_index = invokedynamic_cp_cache_entry_at(which)->constant_pool_index();
 660     } else {
 661       // change byte-ordering and go via cache
 662       pool_index = remap_instruction_operand_from_cache(which);
 663     }
 664   }
 665   return tag_at(pool_index);
 666 }
 667 
 668 int ConstantPool::impl_klass_ref_index_at(int which, bool uncached) {
 669   guarantee(!ConstantPool::is_invokedynamic_index(which),
 670             "an invokedynamic instruction does not have a klass");
 671   int i = which;
 672   if (!uncached && cache() != NULL) {
 673     // change byte-ordering and go via cache
 674     i = remap_instruction_operand_from_cache(which);
 675   }
 676   assert(tag_at(i).is_field_or_method(), "Corrupted constant pool");
 677   jint ref_index = *int_at_addr(i);
 678   return extract_low_short_from_int(ref_index);
 679 }
 680 
 681 
 682 
 683 int ConstantPool::remap_instruction_operand_from_cache(int operand) {
 684   int cpc_index = operand;
 685   DEBUG_ONLY(cpc_index -= CPCACHE_INDEX_TAG);
 686   assert((int)(u2)cpc_index == cpc_index, "clean u2");
 687   int member_index = cache()->entry_at(cpc_index)->constant_pool_index();
 688   return member_index;
 689 }
 690 
 691 
 692 void ConstantPool::verify_constant_pool_resolve(const constantPoolHandle& this_cp, Klass* k, TRAPS) {
 693   if (!(k->is_instance_klass() || k->is_objArray_klass())) {
 694     return;  // short cut, typeArray klass is always accessible
 695   }
 696   Klass* holder = this_cp->pool_holder();
 697   bool fold_type_to_class = true;
 698   LinkResolver::check_klass_accessability(holder, k, fold_type_to_class, CHECK);
 699 }
 700 
 701 
 702 int ConstantPool::name_ref_index_at(int which_nt) {
 703   jint ref_index = name_and_type_at(which_nt);
 704   return extract_low_short_from_int(ref_index);
 705 }
 706 
 707 
 708 int ConstantPool::signature_ref_index_at(int which_nt) {
 709   jint ref_index = name_and_type_at(which_nt);
 710   return extract_high_short_from_int(ref_index);
 711 }
 712 
 713 
 714 Klass* ConstantPool::klass_ref_at(int which, TRAPS) {
 715   return klass_at(klass_ref_index_at(which), THREAD);
 716 }
 717 
 718 Symbol* ConstantPool::klass_name_at(int which) const {
 719   return symbol_at(klass_slot_at(which).name_index());
 720 }
 721 
 722 Symbol* ConstantPool::klass_ref_at_noresolve(int which) {
 723   jint ref_index = klass_ref_index_at(which);
 724   return klass_at_noresolve(ref_index);
 725 }
 726 
 727 Symbol* ConstantPool::uncached_klass_ref_at_noresolve(int which) {
 728   jint ref_index = uncached_klass_ref_index_at(which);
 729   return klass_at_noresolve(ref_index);
 730 }
 731 
 732 char* ConstantPool::string_at_noresolve(int which) {
 733   return unresolved_string_at(which)->as_C_string();
 734 }
 735 
 736 BasicType ConstantPool::basic_type_for_signature_at(int which) const {
 737   return FieldType::basic_type(symbol_at(which));
 738 }
 739 
 740 
 741 void ConstantPool::resolve_string_constants_impl(const constantPoolHandle& this_cp, TRAPS) {
 742   for (int index = 1; index < this_cp->length(); index++) { // Index 0 is unused
 743     if (this_cp->tag_at(index).is_string()) {
 744       this_cp->string_at(index, CHECK);
 745     }
 746   }
 747 }
 748 
 749 Symbol* ConstantPool::exception_message(const constantPoolHandle& this_cp, int which, constantTag tag, oop pending_exception) {
 750   // Dig out the detailed message to reuse if possible
 751   Symbol* message = java_lang_Throwable::detail_message(pending_exception);
 752   if (message != NULL) {
 753     return message;
 754   }
 755 
 756   // Return specific message for the tag
 757   switch (tag.value()) {
 758   case JVM_CONSTANT_UnresolvedClass:
 759   case JVM_CONSTANT_UnresolvedValue:
 760     // return the class name in the error message
 761     message = this_cp->klass_name_at(which);
 762     break;
 763   case JVM_CONSTANT_MethodHandle:
 764     // return the method handle name in the error message
 765     message = this_cp->method_handle_name_ref_at(which);
 766     break;
 767   case JVM_CONSTANT_MethodType:
 768     // return the method type signature in the error message
 769     message = this_cp->method_type_signature_at(which);
 770     break;
 771   default:
 772     ShouldNotReachHere();
 773   }
 774 
 775   return message;
 776 }
 777 
 778 void ConstantPool::throw_resolution_error(const constantPoolHandle& this_cp, int which, TRAPS) {
 779   Symbol* message = NULL;
 780   Symbol* error = SystemDictionary::find_resolution_error(this_cp, which, &message);
 781   assert(error != NULL && message != NULL, "checking");
 782   CLEAR_PENDING_EXCEPTION;
 783   ResourceMark rm;
 784   THROW_MSG(error, message->as_C_string());
 785 }
 786 
 787 // If resolution for Class, Dynamic constant, MethodHandle or MethodType fails, save the
 788 // exception in the resolution error table, so that the same exception is thrown again.
 789 void ConstantPool::save_and_throw_exception(const constantPoolHandle& this_cp, int which,
 790                                             constantTag tag, TRAPS) {
 791   Symbol* error = PENDING_EXCEPTION->klass()->name();
 792 
 793   int error_tag = tag.error_value();
 794 
 795   if (!PENDING_EXCEPTION->
 796     is_a(SystemDictionary::LinkageError_klass())) {
 797     // Just throw the exception and don't prevent these classes from
 798     // being loaded due to virtual machine errors like StackOverflow
 799     // and OutOfMemoryError, etc, or if the thread was hit by stop()
 800     // Needs clarification to section 5.4.3 of the VM spec (see 6308271)
 801   } else if (this_cp->tag_at(which).value() != error_tag) {
 802     Symbol* message = exception_message(this_cp, which, tag, PENDING_EXCEPTION);
 803     SystemDictionary::add_resolution_error(this_cp, which, error, message);
 804     // CAS in the tag.  If a thread beat us to registering this error that's fine.
 805     // If another thread resolved the reference, this is a race condition. This
 806     // thread may have had a security manager or something temporary.
 807     // This doesn't deterministically get an error.   So why do we save this?
 808     // We save this because jvmti can add classes to the bootclass path after
 809     // this error, so it needs to get the same error if the error is first.
 810     jbyte old_tag = Atomic::cmpxchg((jbyte)error_tag,
 811                             (jbyte*)this_cp->tag_addr_at(which), (jbyte)tag.value());
 812     if (old_tag != error_tag && old_tag != tag.value()) {
 813       // MethodHandles and MethodType doesn't change to resolved version.
 814       assert(this_cp->tag_at(which).is_klass() || this_cp->tag_at(which).is_value_type(), "Wrong tag value");
 815       // Forget the exception and use the resolved class.
 816       CLEAR_PENDING_EXCEPTION;
 817     }
 818   } else {
 819     // some other thread put this in error state
 820     throw_resolution_error(this_cp, which, CHECK);
 821   }
 822 }
 823 
 824 BasicType ConstantPool::basic_type_for_constant_at(int which) {
 825   constantTag tag = tag_at(which);
 826   if (tag.is_dynamic_constant() ||
 827       tag.is_dynamic_constant_in_error()) {
 828     // have to look at the signature for this one
 829     Symbol* constant_type = uncached_signature_ref_at(which);
 830     return FieldType::basic_type(constant_type);
 831   }
 832   return tag.basic_type();
 833 }
 834 
 835 // Called to resolve constants in the constant pool and return an oop.
 836 // Some constant pool entries cache their resolved oop. This is also
 837 // called to create oops from constants to use in arguments for invokedynamic
 838 oop ConstantPool::resolve_constant_at_impl(const constantPoolHandle& this_cp,
 839                                            int index, int cache_index,
 840                                            bool* status_return, TRAPS) {
 841   oop result_oop = NULL;
 842   Handle throw_exception;
 843 
 844   if (cache_index == _possible_index_sentinel) {
 845     // It is possible that this constant is one which is cached in the objects.
 846     // We'll do a linear search.  This should be OK because this usage is rare.
 847     // FIXME: If bootstrap specifiers stress this code, consider putting in
 848     // a reverse index.  Binary search over a short array should do it.
 849     assert(index > 0, "valid index");
 850     cache_index = this_cp->cp_to_object_index(index);
 851   }
 852   assert(cache_index == _no_index_sentinel || cache_index >= 0, "");
 853   assert(index == _no_index_sentinel || index >= 0, "");
 854 
 855   if (cache_index >= 0) {
 856     result_oop = this_cp->resolved_references()->obj_at(cache_index);
 857     if (result_oop != NULL) {
 858       if (result_oop == Universe::the_null_sentinel()) {
 859         DEBUG_ONLY(int temp_index = (index >= 0 ? index : this_cp->object_to_cp_index(cache_index)));
 860         assert(this_cp->tag_at(temp_index).is_dynamic_constant(), "only condy uses the null sentinel");
 861         result_oop = NULL;
 862       }
 863       if (status_return != NULL)  (*status_return) = true;
 864       return result_oop;
 865       // That was easy...
 866     }
 867     index = this_cp->object_to_cp_index(cache_index);
 868   }
 869 
 870   jvalue prim_value;  // temp used only in a few cases below
 871 
 872   constantTag tag = this_cp->tag_at(index);
 873 
 874   if (status_return != NULL) {
 875     // don't trigger resolution if the constant might need it
 876     switch (tag.value()) {
 877     case JVM_CONSTANT_Class:
 878     {
 879       CPKlassSlot kslot = this_cp->klass_slot_at(index);
 880       int resolved_klass_index = kslot.resolved_klass_index();
 881       if (this_cp->resolved_klasses()->at(resolved_klass_index) == NULL) {
 882         (*status_return) = false;
 883         return NULL;
 884       }
 885       // the klass is waiting in the CP; go get it
 886       break;
 887     }
 888     case JVM_CONSTANT_String:
 889     case JVM_CONSTANT_Integer:
 890     case JVM_CONSTANT_Float:
 891     case JVM_CONSTANT_Long:
 892     case JVM_CONSTANT_Double:
 893       // these guys trigger OOM at worst
 894       break;
 895     default:
 896       (*status_return) = false;
 897       return NULL;
 898     }
 899     // from now on there is either success or an OOME
 900     (*status_return) = true;
 901   }
 902 
 903   switch (tag.value()) {
 904 
 905   case JVM_CONSTANT_UnresolvedClass:
 906   case JVM_CONSTANT_UnresolvedClassInError:
 907   case JVM_CONSTANT_Class:
 908   case JVM_CONSTANT_UnresolvedValue:
 909   case JVM_CONSTANT_UnresolvedValueInError:
 910   case JVM_CONSTANT_Value:
 911     {
 912       assert(cache_index == _no_index_sentinel, "should not have been set");
 913       Klass* resolved = klass_at_impl(this_cp, index, true, CHECK_NULL);
 914       // ldc wants the java mirror.
 915       result_oop = resolved->java_mirror();
 916       break;
 917     }
 918 
 919   case JVM_CONSTANT_Dynamic:
 920     {
 921       Klass* current_klass  = this_cp->pool_holder();
 922       Symbol* constant_name = this_cp->uncached_name_ref_at(index);
 923       Symbol* constant_type = this_cp->uncached_signature_ref_at(index);
 924 
 925       // The initial step in resolving an unresolved symbolic reference to a
 926       // dynamically-computed constant is to resolve the symbolic reference to a
 927       // method handle which will be the bootstrap method for the dynamically-computed
 928       // constant. If resolution of the java.lang.invoke.MethodHandle for the bootstrap
 929       // method fails, then a MethodHandleInError is stored at the corresponding
 930       // bootstrap method's CP index for the CONSTANT_MethodHandle_info. No need to
 931       // set a DynamicConstantInError here since any subsequent use of this
 932       // bootstrap method will encounter the resolution of MethodHandleInError.
 933       oop bsm_info = this_cp->resolve_bootstrap_specifier_at(index, THREAD);
 934       Exceptions::wrap_dynamic_exception(CHECK_NULL);
 935       assert(bsm_info != NULL, "");
 936       // FIXME: Cache this once per BootstrapMethods entry, not once per CONSTANT_Dynamic.
 937       Handle bootstrap_specifier = Handle(THREAD, bsm_info);
 938 
 939       // Resolve the Dynamically-Computed constant to invoke the BSM in order to obtain the resulting oop.
 940       Handle value = SystemDictionary::link_dynamic_constant(current_klass,
 941                                                              index,
 942                                                              bootstrap_specifier,
 943                                                              constant_name,
 944                                                              constant_type,
 945                                                              THREAD);
 946       result_oop = value();
 947       Exceptions::wrap_dynamic_exception(THREAD);
 948       if (HAS_PENDING_EXCEPTION) {
 949         // Resolution failure of the dynamically-computed constant, save_and_throw_exception
 950         // will check for a LinkageError and store a DynamicConstantInError.
 951         save_and_throw_exception(this_cp, index, tag, CHECK_NULL);
 952       }
 953       BasicType type = FieldType::basic_type(constant_type);
 954       if (!is_reference_type(type)) {
 955         // Make sure the primitive value is properly boxed.
 956         // This is a JDK responsibility.
 957         const char* fail = NULL;
 958         if (result_oop == NULL) {
 959           fail = "null result instead of box";
 960         } else if (!is_java_primitive(type)) {
 961           // FIXME: support value types via unboxing
 962           fail = "can only handle references and primitives";
 963         } else if (!java_lang_boxing_object::is_instance(result_oop, type)) {
 964           fail = "primitive is not properly boxed";
 965         }
 966         if (fail != NULL) {
 967           // Since this exception is not a LinkageError, throw exception
 968           // but do not save a DynamicInError resolution result.
 969           // See section 5.4.3 of the VM spec.
 970           THROW_MSG_NULL(vmSymbols::java_lang_InternalError(), fail);
 971         }
 972       }
 973       break;
 974     }
 975 
 976   case JVM_CONSTANT_String:
 977     assert(cache_index != _no_index_sentinel, "should have been set");
 978     if (this_cp->is_pseudo_string_at(index)) {
 979       result_oop = this_cp->pseudo_string_at(index, cache_index);
 980       break;
 981     }
 982     result_oop = string_at_impl(this_cp, index, cache_index, CHECK_NULL);
 983     break;
 984 
 985   case JVM_CONSTANT_DynamicInError:
 986   case JVM_CONSTANT_MethodHandleInError:
 987   case JVM_CONSTANT_MethodTypeInError:
 988     {
 989       throw_resolution_error(this_cp, index, CHECK_NULL);
 990       break;
 991     }
 992 
 993   case JVM_CONSTANT_MethodHandle:
 994     {
 995       int ref_kind                 = this_cp->method_handle_ref_kind_at(index);
 996       int callee_index             = this_cp->method_handle_klass_index_at(index);
 997       Symbol*  name =      this_cp->method_handle_name_ref_at(index);
 998       Symbol*  signature = this_cp->method_handle_signature_ref_at(index);
 999       constantTag m_tag  = this_cp->tag_at(this_cp->method_handle_index_at(index));
1000       { ResourceMark rm(THREAD);
1001         log_debug(class, resolve)("resolve JVM_CONSTANT_MethodHandle:%d [%d/%d/%d] %s.%s",
1002                               ref_kind, index, this_cp->method_handle_index_at(index),
1003                               callee_index, name->as_C_string(), signature->as_C_string());
1004       }
1005 
1006       Klass* callee = klass_at_impl(this_cp, callee_index, true, CHECK_NULL);
1007 
1008       // Check constant pool method consistency
1009       if ((callee->is_interface() && m_tag.is_method()) ||
1010           ((!callee->is_interface() && m_tag.is_interface_method()))) {
1011         ResourceMark rm(THREAD);
1012         char buf[400];
1013         jio_snprintf(buf, sizeof(buf),
1014           "Inconsistent constant pool data in classfile for class %s. "
1015           "Method %s%s at index %d is %s and should be %s",
1016           callee->name()->as_C_string(), name->as_C_string(), signature->as_C_string(), index,
1017           callee->is_interface() ? "CONSTANT_MethodRef" : "CONSTANT_InterfaceMethodRef",
1018           callee->is_interface() ? "CONSTANT_InterfaceMethodRef" : "CONSTANT_MethodRef");
1019         THROW_MSG_NULL(vmSymbols::java_lang_IncompatibleClassChangeError(), buf);
1020       }
1021 
1022       Klass* klass = this_cp->pool_holder();
1023       Handle value = SystemDictionary::link_method_handle_constant(klass, ref_kind,
1024                                                                    callee, name, signature,
1025                                                                    THREAD);
1026       result_oop = value();
1027       if (HAS_PENDING_EXCEPTION) {
1028         save_and_throw_exception(this_cp, index, tag, CHECK_NULL);
1029       }
1030       break;
1031     }
1032 
1033   case JVM_CONSTANT_MethodType:
1034     {
1035       Symbol*  signature = this_cp->method_type_signature_at(index);
1036       { ResourceMark rm(THREAD);
1037         log_debug(class, resolve)("resolve JVM_CONSTANT_MethodType [%d/%d] %s",
1038                               index, this_cp->method_type_index_at(index),
1039                               signature->as_C_string());
1040       }
1041       Klass* klass = this_cp->pool_holder();
1042       Handle value = SystemDictionary::find_method_handle_type(signature, klass, THREAD);
1043       result_oop = value();
1044       if (HAS_PENDING_EXCEPTION) {
1045         save_and_throw_exception(this_cp, index, tag, CHECK_NULL);
1046       }
1047       break;
1048     }
1049 
1050   case JVM_CONSTANT_Integer:
1051     assert(cache_index == _no_index_sentinel, "should not have been set");
1052     prim_value.i = this_cp->int_at(index);
1053     result_oop = java_lang_boxing_object::create(T_INT, &prim_value, CHECK_NULL);
1054     break;
1055 
1056   case JVM_CONSTANT_Float:
1057     assert(cache_index == _no_index_sentinel, "should not have been set");
1058     prim_value.f = this_cp->float_at(index);
1059     result_oop = java_lang_boxing_object::create(T_FLOAT, &prim_value, CHECK_NULL);
1060     break;
1061 
1062   case JVM_CONSTANT_Long:
1063     assert(cache_index == _no_index_sentinel, "should not have been set");
1064     prim_value.j = this_cp->long_at(index);
1065     result_oop = java_lang_boxing_object::create(T_LONG, &prim_value, CHECK_NULL);
1066     break;
1067 
1068   case JVM_CONSTANT_Double:
1069     assert(cache_index == _no_index_sentinel, "should not have been set");
1070     prim_value.d = this_cp->double_at(index);
1071     result_oop = java_lang_boxing_object::create(T_DOUBLE, &prim_value, CHECK_NULL);
1072     break;
1073 
1074   default:
1075     DEBUG_ONLY( tty->print_cr("*** %p: tag at CP[%d/%d] = %d",
1076                               this_cp(), index, cache_index, tag.value()));
1077     assert(false, "unexpected constant tag");
1078     break;
1079   }
1080 
1081   if (cache_index >= 0) {
1082     // Benign race condition:  resolved_references may already be filled in.
1083     // The important thing here is that all threads pick up the same result.
1084     // It doesn't matter which racing thread wins, as long as only one
1085     // result is used by all threads, and all future queries.
1086     oop new_result = (result_oop == NULL ? Universe::the_null_sentinel() : result_oop);
1087     oop old_result = this_cp->resolved_references()
1088       ->atomic_compare_exchange_oop(cache_index, new_result, NULL);
1089     if (old_result == NULL) {
1090       return result_oop;  // was installed
1091     } else {
1092       // Return the winning thread's result.  This can be different than
1093       // the result here for MethodHandles.
1094       if (old_result == Universe::the_null_sentinel())
1095         old_result = NULL;
1096       return old_result;
1097     }
1098   } else {
1099     assert(result_oop != Universe::the_null_sentinel(), "");
1100     return result_oop;
1101   }
1102 }
1103 
1104 oop ConstantPool::uncached_string_at(int which, TRAPS) {
1105   Symbol* sym = unresolved_string_at(which);
1106   oop str = StringTable::intern(sym, CHECK_(NULL));
1107   assert(java_lang_String::is_instance(str), "must be string");
1108   return str;
1109 }
1110 
1111 
1112 oop ConstantPool::resolve_bootstrap_specifier_at_impl(const constantPoolHandle& this_cp, int index, TRAPS) {
1113   assert((this_cp->tag_at(index).is_invoke_dynamic() ||
1114           this_cp->tag_at(index).is_dynamic_constant()), "Corrupted constant pool");
1115   Handle bsm;
1116   int argc;
1117   {
1118     // JVM_CONSTANT_InvokeDynamic is an ordered pair of [bootm, name&mtype], plus optional arguments
1119     // JVM_CONSTANT_Dynamic is an ordered pair of [bootm, name&ftype], plus optional arguments
1120     // In both cases, the bootm, being a JVM_CONSTANT_MethodHandle, has its own cache entry.
1121     // It is accompanied by the optional arguments.
1122     int bsm_index = this_cp->invoke_dynamic_bootstrap_method_ref_index_at(index);
1123     oop bsm_oop = this_cp->resolve_possibly_cached_constant_at(bsm_index, CHECK_NULL);
1124     if (!java_lang_invoke_MethodHandle::is_instance(bsm_oop)) {
1125       THROW_MSG_NULL(vmSymbols::java_lang_LinkageError(), "BSM not an MethodHandle");
1126     }
1127 
1128     // Extract the optional static arguments.
1129     argc = this_cp->invoke_dynamic_argument_count_at(index);
1130 
1131     // if there are no static arguments, return the bsm by itself:
1132     if (argc == 0 && UseBootstrapCallInfo < 2)  return bsm_oop;
1133 
1134     bsm = Handle(THREAD, bsm_oop);
1135   }
1136 
1137   // We are going to return an ordered pair of {bsm, info}, using a 2-array.
1138   objArrayHandle info;
1139   {
1140     objArrayOop info_oop = oopFactory::new_objArray(SystemDictionary::Object_klass(), 2, CHECK_NULL);
1141     info = objArrayHandle(THREAD, info_oop);
1142   }
1143 
1144   info->obj_at_put(0, bsm());
1145 
1146   bool use_BSCI;
1147   switch (UseBootstrapCallInfo) {
1148   default: use_BSCI = true;  break;  // stress mode
1149   case 0:  use_BSCI = false; break;  // stress mode
1150   case 1:                            // normal mode
1151     // If we were to support an alternative mode of BSM invocation,
1152     // we'd convert to pull mode here if the BSM could be a candidate
1153     // for that alternative mode.  We can't easily test for things
1154     // like varargs here, but we can get away with approximate testing,
1155     // since the JDK runtime will make up the difference either way.
1156     // For now, exercise the pull-mode path if the BSM is of arity 2,
1157     // or if there is a potential condy loop (see below).
1158     oop mt_oop = java_lang_invoke_MethodHandle::type(bsm());
1159     use_BSCI = (java_lang_invoke_MethodType::ptype_count(mt_oop) == 2);
1160     break;
1161   }
1162 
1163   // Here's a reason to use BSCI even if it wasn't requested:
1164   // If a condy uses a condy argument, we want to avoid infinite
1165   // recursion (condy loops) in the C code.  It's OK in Java,
1166   // because Java has stack overflow checking, so we punt
1167   // potentially cyclic cases from C to Java.
1168   if (!use_BSCI && this_cp->tag_at(index).is_dynamic_constant()) {
1169     bool found_unresolved_condy = false;
1170     for (int i = 0; i < argc; i++) {
1171       int arg_index = this_cp->invoke_dynamic_argument_index_at(index, i);
1172       if (this_cp->tag_at(arg_index).is_dynamic_constant()) {
1173         // potential recursion point condy -> condy
1174         bool found_it = false;
1175         this_cp->find_cached_constant_at(arg_index, found_it, CHECK_NULL);
1176         if (!found_it) { found_unresolved_condy = true; break; }
1177       }
1178     }
1179     if (found_unresolved_condy)
1180       use_BSCI = true;
1181   }
1182 
1183   const int SMALL_ARITY = 5;
1184   if (use_BSCI && argc <= SMALL_ARITY && UseBootstrapCallInfo <= 2) {
1185     // If there are only a few arguments, and none of them need linking,
1186     // push them, instead of asking the JDK runtime to turn around and
1187     // pull them, saving a JVM/JDK transition in some simple cases.
1188     bool all_resolved = true;
1189     for (int i = 0; i < argc; i++) {
1190       bool found_it = false;
1191       int arg_index = this_cp->invoke_dynamic_argument_index_at(index, i);
1192       this_cp->find_cached_constant_at(arg_index, found_it, CHECK_NULL);
1193       if (!found_it) { all_resolved = false; break; }
1194     }
1195     if (all_resolved)
1196       use_BSCI = false;
1197   }
1198 
1199   if (!use_BSCI) {
1200     // return {bsm, {arg...}}; resolution of arguments is done immediately, before JDK code is called
1201     objArrayOop args_oop = oopFactory::new_objArray(SystemDictionary::Object_klass(), argc, CHECK_NULL);
1202     info->obj_at_put(1, args_oop);   // may overwrite with args[0] below
1203     objArrayHandle args(THREAD, args_oop);
1204     copy_bootstrap_arguments_at_impl(this_cp, index, 0, argc, args, 0, true, Handle(), CHECK_NULL);
1205     if (argc == 1) {
1206       // try to discard the singleton array
1207       oop arg_oop = args->obj_at(0);
1208       if (arg_oop != NULL && !arg_oop->is_array()) {
1209         // JVM treats arrays and nulls specially in this position,
1210         // but other things are just single arguments
1211         info->obj_at_put(1, arg_oop);
1212       }
1213     }
1214   } else {
1215     // return {bsm, {arg_count, pool_index}}; JDK code must pull the arguments as needed
1216     typeArrayOop ints_oop = oopFactory::new_typeArray(T_INT, 2, CHECK_NULL);
1217     ints_oop->int_at_put(0, argc);
1218     ints_oop->int_at_put(1, index);
1219     info->obj_at_put(1, ints_oop);
1220   }
1221   return info();
1222 }
1223 
1224 void ConstantPool::copy_bootstrap_arguments_at_impl(const constantPoolHandle& this_cp, int index,
1225                                                     int start_arg, int end_arg,
1226                                                     objArrayHandle info, int pos,
1227                                                     bool must_resolve, Handle if_not_available,
1228                                                     TRAPS) {
1229   int argc;
1230   int limit = pos + end_arg - start_arg;
1231   // checks: index in range [0..this_cp->length),
1232   // tag at index, start..end in range [0..argc],
1233   // info array non-null, pos..limit in [0..info.length]
1234   if ((0 >= index    || index >= this_cp->length())  ||
1235       !(this_cp->tag_at(index).is_invoke_dynamic()    ||
1236         this_cp->tag_at(index).is_dynamic_constant()) ||
1237       (0 > start_arg || start_arg > end_arg) ||
1238       (end_arg > (argc = this_cp->invoke_dynamic_argument_count_at(index))) ||
1239       (0 > pos       || pos > limit)         ||
1240       (info.is_null() || limit > info->length())) {
1241     // An index or something else went wrong; throw an error.
1242     // Since this is an internal API, we don't expect this,
1243     // so we don't bother to craft a nice message.
1244     THROW_MSG(vmSymbols::java_lang_LinkageError(), "bad BSM argument access");
1245   }
1246   // now we can loop safely
1247   int info_i = pos;
1248   for (int i = start_arg; i < end_arg; i++) {
1249     int arg_index = this_cp->invoke_dynamic_argument_index_at(index, i);
1250     oop arg_oop;
1251     if (must_resolve) {
1252       arg_oop = this_cp->resolve_possibly_cached_constant_at(arg_index, CHECK);
1253     } else {
1254       bool found_it = false;
1255       arg_oop = this_cp->find_cached_constant_at(arg_index, found_it, CHECK);
1256       if (!found_it)  arg_oop = if_not_available();
1257     }
1258     info->obj_at_put(info_i++, arg_oop);
1259   }
1260 }
1261 
1262 oop ConstantPool::string_at_impl(const constantPoolHandle& this_cp, int which, int obj_index, TRAPS) {
1263   // If the string has already been interned, this entry will be non-null
1264   oop str = this_cp->resolved_references()->obj_at(obj_index);
1265   assert(str != Universe::the_null_sentinel(), "");
1266   if (str != NULL) return str;
1267   Symbol* sym = this_cp->unresolved_string_at(which);
1268   str = StringTable::intern(sym, CHECK_(NULL));
1269   this_cp->string_at_put(which, obj_index, str);
1270   assert(java_lang_String::is_instance(str), "must be string");
1271   return str;
1272 }
1273 
1274 
1275 bool ConstantPool::klass_name_at_matches(const InstanceKlass* k, int which) {
1276   // Names are interned, so we can compare Symbol*s directly
1277   Symbol* cp_name = klass_name_at(which);
1278   return (cp_name == k->name());
1279 }
1280 
1281 
1282 // Iterate over symbols and decrement ones which are Symbol*s
1283 // This is done during GC.
1284 // Only decrement the UTF8 symbols. Strings point to
1285 // these symbols but didn't increment the reference count.
1286 void ConstantPool::unreference_symbols() {
1287   for (int index = 1; index < length(); index++) { // Index 0 is unused
1288     constantTag tag = tag_at(index);
1289     if (tag.is_symbol()) {
1290       symbol_at(index)->decrement_refcount();
1291     }
1292   }
1293 }
1294 
1295 
1296 // Compare this constant pool's entry at index1 to the constant pool
1297 // cp2's entry at index2.
1298 bool ConstantPool::compare_entry_to(int index1, const constantPoolHandle& cp2,
1299        int index2, TRAPS) {
1300 
1301   // The error tags are equivalent to non-error tags when comparing
1302   jbyte t1 = tag_at(index1).non_error_value();
1303   jbyte t2 = cp2->tag_at(index2).non_error_value();
1304 
1305   if (t1 != t2) {
1306     // Not the same entry type so there is nothing else to check. Note
1307     // that this style of checking will consider resolved/unresolved
1308     // class pairs as different.
1309     // From the ConstantPool* API point of view, this is correct
1310     // behavior. See VM_RedefineClasses::merge_constant_pools() to see how this
1311     // plays out in the context of ConstantPool* merging.
1312     return false;
1313   }
1314 
1315   switch (t1) {
1316   case JVM_CONSTANT_Class:
1317   case JVM_CONSTANT_Value:
1318   {
1319     Klass* k1 = klass_at(index1, CHECK_false);
1320     Klass* k2 = cp2->klass_at(index2, CHECK_false);
1321     if (k1 == k2) {
1322       return true;
1323     }
1324   } break;
1325 
1326   case JVM_CONSTANT_ClassIndex:
1327   {
1328     int recur1 = klass_index_at(index1);
1329     int recur2 = cp2->klass_index_at(index2);
1330     bool match = compare_entry_to(recur1, cp2, recur2, CHECK_false);
1331     if (match) {
1332       return true;
1333     }
1334   } break;
1335 
1336   case JVM_CONSTANT_ValueIndex:
1337   {
1338     int recur1 = value_type_index_at(index1);
1339     int recur2 = cp2->value_type_index_at(index2);
1340     bool match = compare_entry_to(recur1, cp2, recur2, CHECK_false);
1341     if (match) {
1342       return true;
1343     }
1344   } break;
1345 
1346   case JVM_CONSTANT_Double:
1347   {
1348     jdouble d1 = double_at(index1);
1349     jdouble d2 = cp2->double_at(index2);
1350     if (d1 == d2) {
1351       return true;
1352     }
1353   } break;
1354 
1355   case JVM_CONSTANT_Fieldref:
1356   case JVM_CONSTANT_InterfaceMethodref:
1357   case JVM_CONSTANT_Methodref:
1358   {
1359     int recur1 = uncached_klass_ref_index_at(index1);
1360     int recur2 = cp2->uncached_klass_ref_index_at(index2);
1361     bool match = compare_entry_to(recur1, cp2, recur2, CHECK_false);
1362     if (match) {
1363       recur1 = uncached_name_and_type_ref_index_at(index1);
1364       recur2 = cp2->uncached_name_and_type_ref_index_at(index2);
1365       match = compare_entry_to(recur1, cp2, recur2, CHECK_false);
1366       if (match) {
1367         return true;
1368       }
1369     }
1370   } break;
1371 
1372   case JVM_CONSTANT_Float:
1373   {
1374     jfloat f1 = float_at(index1);
1375     jfloat f2 = cp2->float_at(index2);
1376     if (f1 == f2) {
1377       return true;
1378     }
1379   } break;
1380 
1381   case JVM_CONSTANT_Integer:
1382   {
1383     jint i1 = int_at(index1);
1384     jint i2 = cp2->int_at(index2);
1385     if (i1 == i2) {
1386       return true;
1387     }
1388   } break;
1389 
1390   case JVM_CONSTANT_Long:
1391   {
1392     jlong l1 = long_at(index1);
1393     jlong l2 = cp2->long_at(index2);
1394     if (l1 == l2) {
1395       return true;
1396     }
1397   } break;
1398 
1399   case JVM_CONSTANT_NameAndType:
1400   {
1401     int recur1 = name_ref_index_at(index1);
1402     int recur2 = cp2->name_ref_index_at(index2);
1403     bool match = compare_entry_to(recur1, cp2, recur2, CHECK_false);
1404     if (match) {
1405       recur1 = signature_ref_index_at(index1);
1406       recur2 = cp2->signature_ref_index_at(index2);
1407       match = compare_entry_to(recur1, cp2, recur2, CHECK_false);
1408       if (match) {
1409         return true;
1410       }
1411     }
1412   } break;
1413 
1414   case JVM_CONSTANT_StringIndex:
1415   {
1416     int recur1 = string_index_at(index1);
1417     int recur2 = cp2->string_index_at(index2);
1418     bool match = compare_entry_to(recur1, cp2, recur2, CHECK_false);
1419     if (match) {
1420       return true;
1421     }
1422   } break;
1423 
1424   case JVM_CONSTANT_UnresolvedClass:
1425   case JVM_CONSTANT_UnresolvedValue:
1426   {
1427     Symbol* k1 = klass_name_at(index1);
1428     Symbol* k2 = cp2->klass_name_at(index2);
1429     if (k1 == k2) {
1430       return true;
1431     }
1432   } break;
1433 
1434   case JVM_CONSTANT_MethodType:
1435   {
1436     int k1 = method_type_index_at(index1);
1437     int k2 = cp2->method_type_index_at(index2);
1438     bool match = compare_entry_to(k1, cp2, k2, CHECK_false);
1439     if (match) {
1440       return true;
1441     }
1442   } break;
1443 
1444   case JVM_CONSTANT_MethodHandle:
1445   {
1446     int k1 = method_handle_ref_kind_at(index1);
1447     int k2 = cp2->method_handle_ref_kind_at(index2);
1448     if (k1 == k2) {
1449       int i1 = method_handle_index_at(index1);
1450       int i2 = cp2->method_handle_index_at(index2);
1451       bool match = compare_entry_to(i1, cp2, i2, CHECK_false);
1452       if (match) {
1453         return true;
1454       }
1455     }
1456   } break;
1457 
1458   case JVM_CONSTANT_Dynamic:
1459   {
1460     int k1 = invoke_dynamic_name_and_type_ref_index_at(index1);
1461     int k2 = cp2->invoke_dynamic_name_and_type_ref_index_at(index2);
1462     int i1 = invoke_dynamic_bootstrap_specifier_index(index1);
1463     int i2 = cp2->invoke_dynamic_bootstrap_specifier_index(index2);
1464     // separate statements and variables because CHECK_false is used
1465     bool match_entry = compare_entry_to(k1, cp2, k2, CHECK_false);
1466     bool match_operand = compare_operand_to(i1, cp2, i2, CHECK_false);
1467     return (match_entry && match_operand);
1468   } break;
1469 
1470   case JVM_CONSTANT_InvokeDynamic:
1471   {
1472     int k1 = invoke_dynamic_name_and_type_ref_index_at(index1);
1473     int k2 = cp2->invoke_dynamic_name_and_type_ref_index_at(index2);
1474     int i1 = invoke_dynamic_bootstrap_specifier_index(index1);
1475     int i2 = cp2->invoke_dynamic_bootstrap_specifier_index(index2);
1476     // separate statements and variables because CHECK_false is used
1477     bool match_entry = compare_entry_to(k1, cp2, k2, CHECK_false);
1478     bool match_operand = compare_operand_to(i1, cp2, i2, CHECK_false);
1479     return (match_entry && match_operand);
1480   } break;
1481 
1482   case JVM_CONSTANT_String:
1483   {
1484     Symbol* s1 = unresolved_string_at(index1);
1485     Symbol* s2 = cp2->unresolved_string_at(index2);
1486     if (s1 == s2) {
1487       return true;
1488     }
1489   } break;
1490 
1491   case JVM_CONSTANT_Utf8:
1492   {
1493     Symbol* s1 = symbol_at(index1);
1494     Symbol* s2 = cp2->symbol_at(index2);
1495     if (s1 == s2) {
1496       return true;
1497     }
1498   } break;
1499 
1500   // Invalid is used as the tag for the second constant pool entry
1501   // occupied by JVM_CONSTANT_Double or JVM_CONSTANT_Long. It should
1502   // not be seen by itself.
1503   case JVM_CONSTANT_Invalid: // fall through
1504 
1505   default:
1506     ShouldNotReachHere();
1507     break;
1508   }
1509 
1510   return false;
1511 } // end compare_entry_to()
1512 
1513 
1514 // Resize the operands array with delta_len and delta_size.
1515 // Used in RedefineClasses for CP merge.
1516 void ConstantPool::resize_operands(int delta_len, int delta_size, TRAPS) {
1517   int old_len  = operand_array_length(operands());
1518   int new_len  = old_len + delta_len;
1519   int min_len  = (delta_len > 0) ? old_len : new_len;
1520 
1521   int old_size = operands()->length();
1522   int new_size = old_size + delta_size;
1523   int min_size = (delta_size > 0) ? old_size : new_size;
1524 
1525   ClassLoaderData* loader_data = pool_holder()->class_loader_data();
1526   Array<u2>* new_ops = MetadataFactory::new_array<u2>(loader_data, new_size, CHECK);
1527 
1528   // Set index in the resized array for existing elements only
1529   for (int idx = 0; idx < min_len; idx++) {
1530     int offset = operand_offset_at(idx);                       // offset in original array
1531     operand_offset_at_put(new_ops, idx, offset + 2*delta_len); // offset in resized array
1532   }
1533   // Copy the bootstrap specifiers only
1534   Copy::conjoint_memory_atomic(operands()->adr_at(2*old_len),
1535                                new_ops->adr_at(2*new_len),
1536                                (min_size - 2*min_len) * sizeof(u2));
1537   // Explicitly deallocate old operands array.
1538   // Note, it is not needed for 7u backport.
1539   if ( operands() != NULL) { // the safety check
1540     MetadataFactory::free_array<u2>(loader_data, operands());
1541   }
1542   set_operands(new_ops);
1543 } // end resize_operands()
1544 
1545 
1546 // Extend the operands array with the length and size of the ext_cp operands.
1547 // Used in RedefineClasses for CP merge.
1548 void ConstantPool::extend_operands(const constantPoolHandle& ext_cp, TRAPS) {
1549   int delta_len = operand_array_length(ext_cp->operands());
1550   if (delta_len == 0) {
1551     return; // nothing to do
1552   }
1553   int delta_size = ext_cp->operands()->length();
1554 
1555   assert(delta_len  > 0 && delta_size > 0, "extended operands array must be bigger");
1556 
1557   if (operand_array_length(operands()) == 0) {
1558     ClassLoaderData* loader_data = pool_holder()->class_loader_data();
1559     Array<u2>* new_ops = MetadataFactory::new_array<u2>(loader_data, delta_size, CHECK);
1560     // The first element index defines the offset of second part
1561     operand_offset_at_put(new_ops, 0, 2*delta_len); // offset in new array
1562     set_operands(new_ops);
1563   } else {
1564     resize_operands(delta_len, delta_size, CHECK);
1565   }
1566 
1567 } // end extend_operands()
1568 
1569 
1570 // Shrink the operands array to a smaller array with new_len length.
1571 // Used in RedefineClasses for CP merge.
1572 void ConstantPool::shrink_operands(int new_len, TRAPS) {
1573   int old_len = operand_array_length(operands());
1574   if (new_len == old_len) {
1575     return; // nothing to do
1576   }
1577   assert(new_len < old_len, "shrunken operands array must be smaller");
1578 
1579   int free_base  = operand_next_offset_at(new_len - 1);
1580   int delta_len  = new_len - old_len;
1581   int delta_size = 2*delta_len + free_base - operands()->length();
1582 
1583   resize_operands(delta_len, delta_size, CHECK);
1584 
1585 } // end shrink_operands()
1586 
1587 
1588 void ConstantPool::copy_operands(const constantPoolHandle& from_cp,
1589                                  const constantPoolHandle& to_cp,
1590                                  TRAPS) {
1591 
1592   int from_oplen = operand_array_length(from_cp->operands());
1593   int old_oplen  = operand_array_length(to_cp->operands());
1594   if (from_oplen != 0) {
1595     ClassLoaderData* loader_data = to_cp->pool_holder()->class_loader_data();
1596     // append my operands to the target's operands array
1597     if (old_oplen == 0) {
1598       // Can't just reuse from_cp's operand list because of deallocation issues
1599       int len = from_cp->operands()->length();
1600       Array<u2>* new_ops = MetadataFactory::new_array<u2>(loader_data, len, CHECK);
1601       Copy::conjoint_memory_atomic(
1602           from_cp->operands()->adr_at(0), new_ops->adr_at(0), len * sizeof(u2));
1603       to_cp->set_operands(new_ops);
1604     } else {
1605       int old_len  = to_cp->operands()->length();
1606       int from_len = from_cp->operands()->length();
1607       int old_off  = old_oplen * sizeof(u2);
1608       int from_off = from_oplen * sizeof(u2);
1609       // Use the metaspace for the destination constant pool
1610       Array<u2>* new_operands = MetadataFactory::new_array<u2>(loader_data, old_len + from_len, CHECK);
1611       int fillp = 0, len = 0;
1612       // first part of dest
1613       Copy::conjoint_memory_atomic(to_cp->operands()->adr_at(0),
1614                                    new_operands->adr_at(fillp),
1615                                    (len = old_off) * sizeof(u2));
1616       fillp += len;
1617       // first part of src
1618       Copy::conjoint_memory_atomic(from_cp->operands()->adr_at(0),
1619                                    new_operands->adr_at(fillp),
1620                                    (len = from_off) * sizeof(u2));
1621       fillp += len;
1622       // second part of dest
1623       Copy::conjoint_memory_atomic(to_cp->operands()->adr_at(old_off),
1624                                    new_operands->adr_at(fillp),
1625                                    (len = old_len - old_off) * sizeof(u2));
1626       fillp += len;
1627       // second part of src
1628       Copy::conjoint_memory_atomic(from_cp->operands()->adr_at(from_off),
1629                                    new_operands->adr_at(fillp),
1630                                    (len = from_len - from_off) * sizeof(u2));
1631       fillp += len;
1632       assert(fillp == new_operands->length(), "");
1633 
1634       // Adjust indexes in the first part of the copied operands array.
1635       for (int j = 0; j < from_oplen; j++) {
1636         int offset = operand_offset_at(new_operands, old_oplen + j);
1637         assert(offset == operand_offset_at(from_cp->operands(), j), "correct copy");
1638         offset += old_len;  // every new tuple is preceded by old_len extra u2's
1639         operand_offset_at_put(new_operands, old_oplen + j, offset);
1640       }
1641 
1642       // replace target operands array with combined array
1643       to_cp->set_operands(new_operands);
1644     }
1645   }
1646 } // end copy_operands()
1647 
1648 
1649 // Copy this constant pool's entries at start_i to end_i (inclusive)
1650 // to the constant pool to_cp's entries starting at to_i. A total of
1651 // (end_i - start_i) + 1 entries are copied.
1652 void ConstantPool::copy_cp_to_impl(const constantPoolHandle& from_cp, int start_i, int end_i,
1653        const constantPoolHandle& to_cp, int to_i, TRAPS) {
1654 
1655 
1656   int dest_i = to_i;  // leave original alone for debug purposes
1657 
1658   for (int src_i = start_i; src_i <= end_i; /* see loop bottom */ ) {
1659     copy_entry_to(from_cp, src_i, to_cp, dest_i, CHECK);
1660 
1661     switch (from_cp->tag_at(src_i).value()) {
1662     case JVM_CONSTANT_Double:
1663     case JVM_CONSTANT_Long:
1664       // double and long take two constant pool entries
1665       src_i += 2;
1666       dest_i += 2;
1667       break;
1668 
1669     default:
1670       // all others take one constant pool entry
1671       src_i++;
1672       dest_i++;
1673       break;
1674     }
1675   }
1676   copy_operands(from_cp, to_cp, CHECK);
1677 
1678 } // end copy_cp_to_impl()
1679 
1680 
1681 // Copy this constant pool's entry at from_i to the constant pool
1682 // to_cp's entry at to_i.
1683 void ConstantPool::copy_entry_to(const constantPoolHandle& from_cp, int from_i,
1684                                         const constantPoolHandle& to_cp, int to_i,
1685                                         TRAPS) {
1686 
1687   int tag = from_cp->tag_at(from_i).value();
1688   switch (tag) {
1689   case JVM_CONSTANT_ClassIndex:
1690   {
1691     jint ki = from_cp->klass_index_at(from_i);
1692     to_cp->klass_index_at_put(to_i, ki);
1693   } break;
1694 
1695   case JVM_CONSTANT_ValueIndex:
1696   {
1697     jint ki = from_cp->klass_index_at(from_i);
1698     to_cp->klass_index_at_put(to_i, ki);
1699   } break;
1700 
1701   case JVM_CONSTANT_Double:
1702   {
1703     jdouble d = from_cp->double_at(from_i);
1704     to_cp->double_at_put(to_i, d);
1705     // double takes two constant pool entries so init second entry's tag
1706     to_cp->tag_at_put(to_i + 1, JVM_CONSTANT_Invalid);
1707   } break;
1708 
1709   case JVM_CONSTANT_Fieldref:
1710   {
1711     int class_index = from_cp->uncached_klass_ref_index_at(from_i);
1712     int name_and_type_index = from_cp->uncached_name_and_type_ref_index_at(from_i);
1713     to_cp->field_at_put(to_i, class_index, name_and_type_index);
1714   } break;
1715 
1716   case JVM_CONSTANT_Float:
1717   {
1718     jfloat f = from_cp->float_at(from_i);
1719     to_cp->float_at_put(to_i, f);
1720   } break;
1721 
1722   case JVM_CONSTANT_Integer:
1723   {
1724     jint i = from_cp->int_at(from_i);
1725     to_cp->int_at_put(to_i, i);
1726   } break;
1727 
1728   case JVM_CONSTANT_InterfaceMethodref:
1729   {
1730     int class_index = from_cp->uncached_klass_ref_index_at(from_i);
1731     int name_and_type_index = from_cp->uncached_name_and_type_ref_index_at(from_i);
1732     to_cp->interface_method_at_put(to_i, class_index, name_and_type_index);
1733   } break;
1734 
1735   case JVM_CONSTANT_Long:
1736   {
1737     jlong l = from_cp->long_at(from_i);
1738     to_cp->long_at_put(to_i, l);
1739     // long takes two constant pool entries so init second entry's tag
1740     to_cp->tag_at_put(to_i + 1, JVM_CONSTANT_Invalid);
1741   } break;
1742 
1743   case JVM_CONSTANT_Methodref:
1744   {
1745     int class_index = from_cp->uncached_klass_ref_index_at(from_i);
1746     int name_and_type_index = from_cp->uncached_name_and_type_ref_index_at(from_i);
1747     to_cp->method_at_put(to_i, class_index, name_and_type_index);
1748   } break;
1749 
1750   case JVM_CONSTANT_NameAndType:
1751   {
1752     int name_ref_index = from_cp->name_ref_index_at(from_i);
1753     int signature_ref_index = from_cp->signature_ref_index_at(from_i);
1754     to_cp->name_and_type_at_put(to_i, name_ref_index, signature_ref_index);
1755   } break;
1756 
1757   case JVM_CONSTANT_StringIndex:
1758   {
1759     jint si = from_cp->string_index_at(from_i);
1760     to_cp->string_index_at_put(to_i, si);
1761   } break;
1762 
1763   case JVM_CONSTANT_Class:
1764   case JVM_CONSTANT_UnresolvedClass:
1765   case JVM_CONSTANT_UnresolvedClassInError:
1766   {
1767     // Revert to JVM_CONSTANT_ClassIndex
1768     int name_index = from_cp->klass_slot_at(from_i).name_index();
1769     assert(from_cp->tag_at(name_index).is_symbol(), "sanity");
1770     to_cp->klass_index_at_put(to_i, name_index);
1771   } break;
1772 
1773   case JVM_CONSTANT_Value:
1774   case JVM_CONSTANT_UnresolvedValue:
1775   case JVM_CONSTANT_UnresolvedValueInError:
1776   {
1777     // Revert to JVM_CONSTANT_ValueIndex
1778     int name_index = from_cp->klass_slot_at(from_i).name_index();
1779     assert(from_cp->tag_at(name_index).is_symbol(), "sanity");
1780     to_cp->value_type_index_at_put(to_i, name_index);
1781   } break;
1782 
1783   case JVM_CONSTANT_String:
1784   {
1785     Symbol* s = from_cp->unresolved_string_at(from_i);
1786     to_cp->unresolved_string_at_put(to_i, s);
1787   } break;
1788 
1789   case JVM_CONSTANT_Utf8:
1790   {
1791     Symbol* s = from_cp->symbol_at(from_i);
1792     // Need to increase refcount, the old one will be thrown away and deferenced
1793     s->increment_refcount();
1794     to_cp->symbol_at_put(to_i, s);
1795   } break;
1796 
1797   case JVM_CONSTANT_MethodType:
1798   case JVM_CONSTANT_MethodTypeInError:
1799   {
1800     jint k = from_cp->method_type_index_at(from_i);
1801     to_cp->method_type_index_at_put(to_i, k);
1802   } break;
1803 
1804   case JVM_CONSTANT_MethodHandle:
1805   case JVM_CONSTANT_MethodHandleInError:
1806   {
1807     int k1 = from_cp->method_handle_ref_kind_at(from_i);
1808     int k2 = from_cp->method_handle_index_at(from_i);
1809     to_cp->method_handle_index_at_put(to_i, k1, k2);
1810   } break;
1811 
1812   case JVM_CONSTANT_Dynamic:
1813   case JVM_CONSTANT_DynamicInError:
1814   {
1815     int k1 = from_cp->invoke_dynamic_bootstrap_specifier_index(from_i);
1816     int k2 = from_cp->invoke_dynamic_name_and_type_ref_index_at(from_i);
1817     k1 += operand_array_length(to_cp->operands());  // to_cp might already have operands
1818     to_cp->dynamic_constant_at_put(to_i, k1, k2);
1819   } break;
1820 
1821   case JVM_CONSTANT_InvokeDynamic:
1822   {
1823     int k1 = from_cp->invoke_dynamic_bootstrap_specifier_index(from_i);
1824     int k2 = from_cp->invoke_dynamic_name_and_type_ref_index_at(from_i);
1825     k1 += operand_array_length(to_cp->operands());  // to_cp might already have operands
1826     to_cp->invoke_dynamic_at_put(to_i, k1, k2);
1827   } break;
1828 
1829   // Invalid is used as the tag for the second constant pool entry
1830   // occupied by JVM_CONSTANT_Double or JVM_CONSTANT_Long. It should
1831   // not be seen by itself.
1832   case JVM_CONSTANT_Invalid: // fall through
1833 
1834   default:
1835   {
1836     ShouldNotReachHere();
1837   } break;
1838   }
1839 } // end copy_entry_to()
1840 
1841 // Search constant pool search_cp for an entry that matches this
1842 // constant pool's entry at pattern_i. Returns the index of a
1843 // matching entry or zero (0) if there is no matching entry.
1844 int ConstantPool::find_matching_entry(int pattern_i,
1845       const constantPoolHandle& search_cp, TRAPS) {
1846 
1847   // index zero (0) is not used
1848   for (int i = 1; i < search_cp->length(); i++) {
1849     bool found = compare_entry_to(pattern_i, search_cp, i, CHECK_0);
1850     if (found) {
1851       return i;
1852     }
1853   }
1854 
1855   return 0;  // entry not found; return unused index zero (0)
1856 } // end find_matching_entry()
1857 
1858 
1859 // Compare this constant pool's bootstrap specifier at idx1 to the constant pool
1860 // cp2's bootstrap specifier at idx2.
1861 bool ConstantPool::compare_operand_to(int idx1, const constantPoolHandle& cp2, int idx2, TRAPS) {
1862   int k1 = operand_bootstrap_method_ref_index_at(idx1);
1863   int k2 = cp2->operand_bootstrap_method_ref_index_at(idx2);
1864   bool match = compare_entry_to(k1, cp2, k2, CHECK_false);
1865 
1866   if (!match) {
1867     return false;
1868   }
1869   int argc = operand_argument_count_at(idx1);
1870   if (argc == cp2->operand_argument_count_at(idx2)) {
1871     for (int j = 0; j < argc; j++) {
1872       k1 = operand_argument_index_at(idx1, j);
1873       k2 = cp2->operand_argument_index_at(idx2, j);
1874       match = compare_entry_to(k1, cp2, k2, CHECK_false);
1875       if (!match) {
1876         return false;
1877       }
1878     }
1879     return true;           // got through loop; all elements equal
1880   }
1881   return false;
1882 } // end compare_operand_to()
1883 
1884 // Search constant pool search_cp for a bootstrap specifier that matches
1885 // this constant pool's bootstrap specifier at pattern_i index.
1886 // Return the index of a matching bootstrap specifier or (-1) if there is no match.
1887 int ConstantPool::find_matching_operand(int pattern_i,
1888                     const constantPoolHandle& search_cp, int search_len, TRAPS) {
1889   for (int i = 0; i < search_len; i++) {
1890     bool found = compare_operand_to(pattern_i, search_cp, i, CHECK_(-1));
1891     if (found) {
1892       return i;
1893     }
1894   }
1895   return -1;  // bootstrap specifier not found; return unused index (-1)
1896 } // end find_matching_operand()
1897 
1898 
1899 #ifndef PRODUCT
1900 
1901 const char* ConstantPool::printable_name_at(int which) {
1902 
1903   constantTag tag = tag_at(which);
1904 
1905   if (tag.is_string()) {
1906     return string_at_noresolve(which);
1907   } else if (tag.is_klass() || tag.is_unresolved_klass() ||
1908              tag.is_value_type() || tag.is_unresolved_value_type()) {
1909     return klass_name_at(which)->as_C_string();
1910   } else if (tag.is_symbol()) {
1911     return symbol_at(which)->as_C_string();
1912   }
1913   return "";
1914 }
1915 
1916 #endif // PRODUCT
1917 
1918 
1919 // JVMTI GetConstantPool support
1920 
1921 // For debugging of constant pool
1922 const bool debug_cpool = false;
1923 
1924 #define DBG(code) do { if (debug_cpool) { (code); } } while(0)
1925 
1926 static void print_cpool_bytes(jint cnt, u1 *bytes) {
1927   const char* WARN_MSG = "Must not be such entry!";
1928   jint size = 0;
1929   u2   idx1, idx2;
1930 
1931   for (jint idx = 1; idx < cnt; idx++) {
1932     jint ent_size = 0;
1933     u1   tag  = *bytes++;
1934     size++;                       // count tag
1935 
1936     printf("const #%03d, tag: %02d ", idx, tag);
1937     switch(tag) {
1938       case JVM_CONSTANT_Invalid: {
1939         printf("Invalid");
1940         break;
1941       }
1942       case JVM_CONSTANT_Unicode: {
1943         printf("Unicode      %s", WARN_MSG);
1944         break;
1945       }
1946       case JVM_CONSTANT_Utf8: {
1947         u2 len = Bytes::get_Java_u2(bytes);
1948         char str[128];
1949         if (len > 127) {
1950            len = 127;
1951         }
1952         strncpy(str, (char *) (bytes+2), len);
1953         str[len] = '\0';
1954         printf("Utf8          \"%s\"", str);
1955         ent_size = 2 + len;
1956         break;
1957       }
1958       case JVM_CONSTANT_Integer: {
1959         u4 val = Bytes::get_Java_u4(bytes);
1960         printf("int          %d", *(int *) &val);
1961         ent_size = 4;
1962         break;
1963       }
1964       case JVM_CONSTANT_Float: {
1965         u4 val = Bytes::get_Java_u4(bytes);
1966         printf("float        %5.3ff", *(float *) &val);
1967         ent_size = 4;
1968         break;
1969       }
1970       case JVM_CONSTANT_Long: {
1971         u8 val = Bytes::get_Java_u8(bytes);
1972         printf("long         " INT64_FORMAT, (int64_t) *(jlong *) &val);
1973         ent_size = 8;
1974         idx++; // Long takes two cpool slots
1975         break;
1976       }
1977       case JVM_CONSTANT_Double: {
1978         u8 val = Bytes::get_Java_u8(bytes);
1979         printf("double       %5.3fd", *(jdouble *)&val);
1980         ent_size = 8;
1981         idx++; // Double takes two cpool slots
1982         break;
1983       }
1984       case JVM_CONSTANT_Class: {
1985         idx1 = Bytes::get_Java_u2(bytes);
1986         printf("class        #%03d", idx1);
1987         ent_size = 2;
1988         break;
1989       }
1990       case JVM_CONSTANT_Value: {
1991         idx1 = Bytes::get_Java_u2(bytes);
1992         printf("class        #%03d", idx1);
1993         ent_size = 2;
1994         break;
1995       }
1996       case JVM_CONSTANT_String: {
1997         idx1 = Bytes::get_Java_u2(bytes);
1998         printf("String       #%03d", idx1);
1999         ent_size = 2;
2000         break;
2001       }
2002       case JVM_CONSTANT_Fieldref: {
2003         idx1 = Bytes::get_Java_u2(bytes);
2004         idx2 = Bytes::get_Java_u2(bytes+2);
2005         printf("Field        #%03d, #%03d", (int) idx1, (int) idx2);
2006         ent_size = 4;
2007         break;
2008       }
2009       case JVM_CONSTANT_Methodref: {
2010         idx1 = Bytes::get_Java_u2(bytes);
2011         idx2 = Bytes::get_Java_u2(bytes+2);
2012         printf("Method       #%03d, #%03d", idx1, idx2);
2013         ent_size = 4;
2014         break;
2015       }
2016       case JVM_CONSTANT_InterfaceMethodref: {
2017         idx1 = Bytes::get_Java_u2(bytes);
2018         idx2 = Bytes::get_Java_u2(bytes+2);
2019         printf("InterfMethod #%03d, #%03d", idx1, idx2);
2020         ent_size = 4;
2021         break;
2022       }
2023       case JVM_CONSTANT_NameAndType: {
2024         idx1 = Bytes::get_Java_u2(bytes);
2025         idx2 = Bytes::get_Java_u2(bytes+2);
2026         printf("NameAndType  #%03d, #%03d", idx1, idx2);
2027         ent_size = 4;
2028         break;
2029       }
2030       case JVM_CONSTANT_ClassIndex: {
2031         printf("ClassIndex  %s", WARN_MSG);
2032         break;
2033       }
2034       case JVM_CONSTANT_UnresolvedClass: {
2035         printf("UnresolvedClass: %s", WARN_MSG);
2036         break;
2037       }
2038       case JVM_CONSTANT_UnresolvedClassInError: {
2039         printf("UnresolvedClassInErr: %s", WARN_MSG);
2040         break;
2041       }
2042       case JVM_CONSTANT_ValueIndex: {
2043         printf("ValueIndex  %s", WARN_MSG);
2044         break;
2045       }
2046       case JVM_CONSTANT_UnresolvedValue: {
2047         printf("UnresolvedValue: %s", WARN_MSG);
2048         break;
2049       }
2050       case JVM_CONSTANT_UnresolvedValueInError: {
2051         printf("UnresolvedValueInErr: %s", WARN_MSG);
2052         break;
2053       }
2054       case JVM_CONSTANT_StringIndex: {
2055         printf("StringIndex: %s", WARN_MSG);
2056         break;
2057       }
2058     }
2059     printf(";\n");
2060     bytes += ent_size;
2061     size  += ent_size;
2062   }
2063   printf("Cpool size: %d\n", size);
2064   fflush(0);
2065   return;
2066 } /* end print_cpool_bytes */
2067 
2068 
2069 // Returns size of constant pool entry.
2070 jint ConstantPool::cpool_entry_size(jint idx) {
2071   switch(tag_at(idx).value()) {
2072     case JVM_CONSTANT_Invalid:
2073     case JVM_CONSTANT_Unicode:
2074       return 1;
2075 
2076     case JVM_CONSTANT_Utf8:
2077       return 3 + symbol_at(idx)->utf8_length();
2078 
2079     case JVM_CONSTANT_Class:
2080     case JVM_CONSTANT_String:
2081     case JVM_CONSTANT_ClassIndex:
2082     case JVM_CONSTANT_UnresolvedClass:
2083     case JVM_CONSTANT_UnresolvedClassInError:
2084     case JVM_CONSTANT_Value:
2085     case JVM_CONSTANT_ValueIndex:
2086     case JVM_CONSTANT_UnresolvedValue:
2087     case JVM_CONSTANT_UnresolvedValueInError:
2088     case JVM_CONSTANT_StringIndex:
2089     case JVM_CONSTANT_MethodType:
2090     case JVM_CONSTANT_MethodTypeInError:
2091       return 3;
2092 
2093     case JVM_CONSTANT_MethodHandle:
2094     case JVM_CONSTANT_MethodHandleInError:
2095       return 4; //tag, ref_kind, ref_index
2096 
2097     case JVM_CONSTANT_Integer:
2098     case JVM_CONSTANT_Float:
2099     case JVM_CONSTANT_Fieldref:
2100     case JVM_CONSTANT_Methodref:
2101     case JVM_CONSTANT_InterfaceMethodref:
2102     case JVM_CONSTANT_NameAndType:
2103       return 5;
2104 
2105     case JVM_CONSTANT_Dynamic:
2106     case JVM_CONSTANT_DynamicInError:
2107     case JVM_CONSTANT_InvokeDynamic:
2108       // u1 tag, u2 bsm, u2 nt
2109       return 5;
2110 
2111     case JVM_CONSTANT_Long:
2112     case JVM_CONSTANT_Double:
2113       return 9;
2114   }
2115   assert(false, "cpool_entry_size: Invalid constant pool entry tag");
2116   return 1;
2117 } /* end cpool_entry_size */
2118 
2119 
2120 // SymbolHashMap is used to find a constant pool index from a string.
2121 // This function fills in SymbolHashMaps, one for utf8s and one for
2122 // class names, returns size of the cpool raw bytes.
2123 jint ConstantPool::hash_entries_to(SymbolHashMap *symmap,
2124                                           SymbolHashMap *classmap) {
2125   jint size = 0;
2126 
2127   for (u2 idx = 1; idx < length(); idx++) {
2128     u2 tag = tag_at(idx).value();
2129     size += cpool_entry_size(idx);
2130 
2131     switch(tag) {
2132       case JVM_CONSTANT_Utf8: {
2133         Symbol* sym = symbol_at(idx);
2134         symmap->add_entry(sym, idx);
2135         DBG(printf("adding symbol entry %s = %d\n", sym->as_utf8(), idx));
2136         break;
2137       }
2138       case JVM_CONSTANT_Class:
2139       case JVM_CONSTANT_UnresolvedClass:
2140       case JVM_CONSTANT_UnresolvedClassInError: {
2141         Symbol* sym = klass_name_at(idx);
2142         classmap->add_entry(sym, idx);
2143         DBG(printf("adding class entry %s = %d\n", sym->as_utf8(), idx));
2144         break;
2145       }
2146       case JVM_CONSTANT_Value:
2147       case JVM_CONSTANT_UnresolvedValue:
2148       case JVM_CONSTANT_UnresolvedValueInError: {
2149         Symbol* sym = klass_name_at(idx);
2150         classmap->add_entry(sym, idx);
2151         DBG(printf("adding value type entry %s = %d\n", sym->as_utf8(), idx));
2152         break;
2153       }
2154       case JVM_CONSTANT_Long:
2155       case JVM_CONSTANT_Double: {
2156         idx++; // Both Long and Double take two cpool slots
2157         break;
2158       }
2159     }
2160   }
2161   return size;
2162 } /* end hash_utf8_entries_to */
2163 
2164 
2165 // Copy cpool bytes.
2166 // Returns:
2167 //    0, in case of OutOfMemoryError
2168 //   -1, in case of internal error
2169 //  > 0, count of the raw cpool bytes that have been copied
2170 int ConstantPool::copy_cpool_bytes(int cpool_size,
2171                                           SymbolHashMap* tbl,
2172                                           unsigned char *bytes) {
2173   u2   idx1, idx2;
2174   jint size  = 0;
2175   jint cnt   = length();
2176   unsigned char *start_bytes = bytes;
2177 
2178   for (jint idx = 1; idx < cnt; idx++) {
2179     u1   tag      = tag_at(idx).value();
2180     jint ent_size = cpool_entry_size(idx);
2181 
2182     assert(size + ent_size <= cpool_size, "Size mismatch");
2183 
2184     *bytes = tag;
2185     DBG(printf("#%03hd tag=%03hd, ", (short)idx, (short)tag));
2186     switch(tag) {
2187       case JVM_CONSTANT_Invalid: {
2188         DBG(printf("JVM_CONSTANT_Invalid"));
2189         break;
2190       }
2191       case JVM_CONSTANT_Unicode: {
2192         assert(false, "Wrong constant pool tag: JVM_CONSTANT_Unicode");
2193         DBG(printf("JVM_CONSTANT_Unicode"));
2194         break;
2195       }
2196       case JVM_CONSTANT_Utf8: {
2197         Symbol* sym = symbol_at(idx);
2198         char*     str = sym->as_utf8();
2199         // Warning! It's crashing on x86 with len = sym->utf8_length()
2200         int       len = (int) strlen(str);
2201         Bytes::put_Java_u2((address) (bytes+1), (u2) len);
2202         for (int i = 0; i < len; i++) {
2203             bytes[3+i] = (u1) str[i];
2204         }
2205         DBG(printf("JVM_CONSTANT_Utf8: %s ", str));
2206         break;
2207       }
2208       case JVM_CONSTANT_Integer: {
2209         jint val = int_at(idx);
2210         Bytes::put_Java_u4((address) (bytes+1), *(u4*)&val);
2211         break;
2212       }
2213       case JVM_CONSTANT_Float: {
2214         jfloat val = float_at(idx);
2215         Bytes::put_Java_u4((address) (bytes+1), *(u4*)&val);
2216         break;
2217       }
2218       case JVM_CONSTANT_Long: {
2219         jlong val = long_at(idx);
2220         Bytes::put_Java_u8((address) (bytes+1), *(u8*)&val);
2221         idx++;             // Long takes two cpool slots
2222         break;
2223       }
2224       case JVM_CONSTANT_Double: {
2225         jdouble val = double_at(idx);
2226         Bytes::put_Java_u8((address) (bytes+1), *(u8*)&val);
2227         idx++;             // Double takes two cpool slots
2228         break;
2229       }
2230       case JVM_CONSTANT_Class:
2231       case JVM_CONSTANT_UnresolvedClass:
2232       case JVM_CONSTANT_UnresolvedClassInError: {
2233         *bytes = JVM_CONSTANT_Class;
2234         Symbol* sym = klass_name_at(idx);
2235         idx1 = tbl->symbol_to_value(sym);
2236         assert(idx1 != 0, "Have not found a hashtable entry");
2237         Bytes::put_Java_u2((address) (bytes+1), idx1);
2238         DBG(printf("JVM_CONSTANT_Class: idx=#%03hd, %s", idx1, sym->as_utf8()));
2239         break;
2240       }
2241       case JVM_CONSTANT_Value:
2242       case JVM_CONSTANT_UnresolvedValue:
2243       case JVM_CONSTANT_UnresolvedValueInError: {
2244         *bytes = JVM_CONSTANT_Value;
2245         Symbol* sym = klass_name_at(idx);
2246         idx1 = tbl->symbol_to_value(sym);
2247         assert(idx1 != 0, "Have not found a hashtable entry");
2248         Bytes::put_Java_u2((address) (bytes+1), idx1);
2249         DBG(printf("JVM_CONSTANT_Value: idx=#%03hd, %s", idx1, sym->as_utf8()));
2250         break;
2251       }
2252       case JVM_CONSTANT_String: {
2253         *bytes = JVM_CONSTANT_String;
2254         Symbol* sym = unresolved_string_at(idx);
2255         idx1 = tbl->symbol_to_value(sym);
2256         assert(idx1 != 0, "Have not found a hashtable entry");
2257         Bytes::put_Java_u2((address) (bytes+1), idx1);
2258         DBG(printf("JVM_CONSTANT_String: idx=#%03hd, %s", idx1, sym->as_utf8()));
2259         break;
2260       }
2261       case JVM_CONSTANT_Fieldref:
2262       case JVM_CONSTANT_Methodref:
2263       case JVM_CONSTANT_InterfaceMethodref: {
2264         idx1 = uncached_klass_ref_index_at(idx);
2265         idx2 = uncached_name_and_type_ref_index_at(idx);
2266         Bytes::put_Java_u2((address) (bytes+1), idx1);
2267         Bytes::put_Java_u2((address) (bytes+3), idx2);
2268         DBG(printf("JVM_CONSTANT_Methodref: %hd %hd", idx1, idx2));
2269         break;
2270       }
2271       case JVM_CONSTANT_NameAndType: {
2272         idx1 = name_ref_index_at(idx);
2273         idx2 = signature_ref_index_at(idx);
2274         Bytes::put_Java_u2((address) (bytes+1), idx1);
2275         Bytes::put_Java_u2((address) (bytes+3), idx2);
2276         DBG(printf("JVM_CONSTANT_NameAndType: %hd %hd", idx1, idx2));
2277         break;
2278       }
2279       case JVM_CONSTANT_ClassIndex: {
2280         *bytes = JVM_CONSTANT_Class;
2281         idx1 = klass_index_at(idx);
2282         Bytes::put_Java_u2((address) (bytes+1), idx1);
2283         DBG(printf("JVM_CONSTANT_ClassIndex: %hd", idx1));
2284         break;
2285       }
2286       case JVM_CONSTANT_ValueIndex: {
2287         *bytes = JVM_CONSTANT_Value;
2288         idx1 = value_type_index_at(idx);
2289         Bytes::put_Java_u2((address) (bytes+1), idx1);
2290         DBG(printf("JVM_CONSTANT_ValueIndex: %hd", idx1));
2291         break;
2292       }
2293       case JVM_CONSTANT_StringIndex: {
2294         *bytes = JVM_CONSTANT_String;
2295         idx1 = string_index_at(idx);
2296         Bytes::put_Java_u2((address) (bytes+1), idx1);
2297         DBG(printf("JVM_CONSTANT_StringIndex: %hd", idx1));
2298         break;
2299       }
2300       case JVM_CONSTANT_MethodHandle:
2301       case JVM_CONSTANT_MethodHandleInError: {
2302         *bytes = JVM_CONSTANT_MethodHandle;
2303         int kind = method_handle_ref_kind_at(idx);
2304         idx1 = method_handle_index_at(idx);
2305         *(bytes+1) = (unsigned char) kind;
2306         Bytes::put_Java_u2((address) (bytes+2), idx1);
2307         DBG(printf("JVM_CONSTANT_MethodHandle: %d %hd", kind, idx1));
2308         break;
2309       }
2310       case JVM_CONSTANT_MethodType:
2311       case JVM_CONSTANT_MethodTypeInError: {
2312         *bytes = JVM_CONSTANT_MethodType;
2313         idx1 = method_type_index_at(idx);
2314         Bytes::put_Java_u2((address) (bytes+1), idx1);
2315         DBG(printf("JVM_CONSTANT_MethodType: %hd", idx1));
2316         break;
2317       }
2318       case JVM_CONSTANT_Dynamic:
2319       case JVM_CONSTANT_DynamicInError: {
2320         *bytes = tag;
2321         idx1 = extract_low_short_from_int(*int_at_addr(idx));
2322         idx2 = extract_high_short_from_int(*int_at_addr(idx));
2323         assert(idx2 == invoke_dynamic_name_and_type_ref_index_at(idx), "correct half of u4");
2324         Bytes::put_Java_u2((address) (bytes+1), idx1);
2325         Bytes::put_Java_u2((address) (bytes+3), idx2);
2326         DBG(printf("JVM_CONSTANT_Dynamic: %hd %hd", idx1, idx2));
2327         break;
2328       }
2329       case JVM_CONSTANT_InvokeDynamic: {
2330         *bytes = tag;
2331         idx1 = extract_low_short_from_int(*int_at_addr(idx));
2332         idx2 = extract_high_short_from_int(*int_at_addr(idx));
2333         assert(idx2 == invoke_dynamic_name_and_type_ref_index_at(idx), "correct half of u4");
2334         Bytes::put_Java_u2((address) (bytes+1), idx1);
2335         Bytes::put_Java_u2((address) (bytes+3), idx2);
2336         DBG(printf("JVM_CONSTANT_InvokeDynamic: %hd %hd", idx1, idx2));
2337         break;
2338       }
2339     }
2340     DBG(printf("\n"));
2341     bytes += ent_size;
2342     size  += ent_size;
2343   }
2344   assert(size == cpool_size, "Size mismatch");
2345 
2346   // Keep temorarily for debugging until it's stable.
2347   DBG(print_cpool_bytes(cnt, start_bytes));
2348   return (int)(bytes - start_bytes);
2349 } /* end copy_cpool_bytes */
2350 
2351 #undef DBG
2352 
2353 
2354 void ConstantPool::set_on_stack(const bool value) {
2355   if (value) {
2356     // Only record if it's not already set.
2357     if (!on_stack()) {
2358       assert(!is_shared(), "should always be set for shared constant pools");
2359       _flags |= _on_stack;
2360       MetadataOnStackMark::record(this);
2361     }
2362   } else {
2363     // Clearing is done single-threadedly.
2364     if (!is_shared()) {
2365       _flags &= ~_on_stack;
2366     }
2367   }
2368 }
2369 
2370 // JSR 292 support for patching constant pool oops after the class is linked and
2371 // the oop array for resolved references are created.
2372 // We can't do this during classfile parsing, which is how the other indexes are
2373 // patched.  The other patches are applied early for some error checking
2374 // so only defer the pseudo_strings.
2375 void ConstantPool::patch_resolved_references(GrowableArray<Handle>* cp_patches) {
2376   for (int index = 1; index < cp_patches->length(); index++) { // Index 0 is unused
2377     Handle patch = cp_patches->at(index);
2378     if (patch.not_null()) {
2379       assert (tag_at(index).is_string(), "should only be string left");
2380       // Patching a string means pre-resolving it.
2381       // The spelling in the constant pool is ignored.
2382       // The constant reference may be any object whatever.
2383       // If it is not a real interned string, the constant is referred
2384       // to as a "pseudo-string", and must be presented to the CP
2385       // explicitly, because it may require scavenging.
2386       int obj_index = cp_to_object_index(index);
2387       pseudo_string_at_put(index, obj_index, patch());
2388      DEBUG_ONLY(cp_patches->at_put(index, Handle());)
2389     }
2390   }
2391 #ifdef ASSERT
2392   // Ensure that all the patches have been used.
2393   for (int index = 0; index < cp_patches->length(); index++) {
2394     assert(cp_patches->at(index).is_null(),
2395            "Unused constant pool patch at %d in class file %s",
2396            index,
2397            pool_holder()->external_name());
2398   }
2399 #endif // ASSERT
2400 }
2401 
2402 #ifndef PRODUCT
2403 
2404 // CompileTheWorld support. Preload all classes loaded references in the passed in constantpool
2405 void ConstantPool::preload_and_initialize_all_classes(ConstantPool* obj, TRAPS) {
2406   guarantee(obj->is_constantPool(), "object must be constant pool");
2407   constantPoolHandle cp(THREAD, (ConstantPool*)obj);
2408   guarantee(cp->pool_holder() != NULL, "must be fully loaded");
2409 
2410   for (int i = 0; i< cp->length();  i++) {
2411     if (cp->tag_at(i).is_unresolved_klass() ||
2412         cp->tag_at(i).is_unresolved_value_type()) {
2413       // This will force loading of the class
2414       Klass* klass = cp->klass_at(i, CHECK);
2415       if (klass->is_instance_klass()) {
2416         // Force initialization of class
2417         InstanceKlass::cast(klass)->initialize(CHECK);
2418       }
2419     }
2420   }
2421 }
2422 
2423 #endif
2424 
2425 
2426 // Printing
2427 
2428 void ConstantPool::print_on(outputStream* st) const {
2429   assert(is_constantPool(), "must be constantPool");
2430   st->print_cr("%s", internal_name());
2431   if (flags() != 0) {
2432     st->print(" - flags: 0x%x", flags());
2433     if (has_preresolution()) st->print(" has_preresolution");
2434     if (on_stack()) st->print(" on_stack");
2435     st->cr();
2436   }
2437   if (pool_holder() != NULL) {
2438     st->print_cr(" - holder: " INTPTR_FORMAT, p2i(pool_holder()));
2439   }
2440   st->print_cr(" - cache: " INTPTR_FORMAT, p2i(cache()));
2441   st->print_cr(" - resolved_references: " INTPTR_FORMAT, p2i(resolved_references()));
2442   st->print_cr(" - reference_map: " INTPTR_FORMAT, p2i(reference_map()));
2443   st->print_cr(" - resolved_klasses: " INTPTR_FORMAT, p2i(resolved_klasses()));
2444 
2445   for (int index = 1; index < length(); index++) {      // Index 0 is unused
2446     ((ConstantPool*)this)->print_entry_on(index, st);
2447     switch (tag_at(index).value()) {
2448       case JVM_CONSTANT_Long :
2449       case JVM_CONSTANT_Double :
2450         index++;   // Skip entry following eigth-byte constant
2451     }
2452 
2453   }
2454   st->cr();
2455 }
2456 
2457 // Print one constant pool entry
2458 void ConstantPool::print_entry_on(const int index, outputStream* st) {
2459   EXCEPTION_MARK;
2460   st->print(" - %3d : ", index);
2461   tag_at(index).print_on(st);
2462   st->print(" : ");
2463   switch (tag_at(index).value()) {
2464     case JVM_CONSTANT_Class :
2465       { Klass* k = klass_at(index, CATCH);
2466         guarantee(k != NULL, "need klass");
2467         k->print_value_on(st);
2468         st->print(" {" PTR_FORMAT "}", p2i(k));
2469       }
2470       break;
2471     case JVM_CONSTANT_Value :
2472       { Klass* k = klass_at(index, CATCH);
2473         guarantee(k != NULL, "need klass");
2474         k->print_value_on(st);
2475         st->print(" {" PTR_FORMAT "}", p2i(k));
2476       }
2477       break;
2478     case JVM_CONSTANT_Fieldref :
2479     case JVM_CONSTANT_Methodref :
2480     case JVM_CONSTANT_InterfaceMethodref :
2481       st->print("klass_index=%d", uncached_klass_ref_index_at(index));
2482       st->print(" name_and_type_index=%d", uncached_name_and_type_ref_index_at(index));
2483       break;
2484     case JVM_CONSTANT_String :
2485       if (is_pseudo_string_at(index)) {
2486         oop anObj = pseudo_string_at(index);
2487         anObj->print_value_on(st);
2488         st->print(" {" PTR_FORMAT "}", p2i(anObj));
2489       } else {
2490         unresolved_string_at(index)->print_value_on(st);
2491       }
2492       break;
2493     case JVM_CONSTANT_Integer :
2494       st->print("%d", int_at(index));
2495       break;
2496     case JVM_CONSTANT_Float :
2497       st->print("%f", float_at(index));
2498       break;
2499     case JVM_CONSTANT_Long :
2500       st->print_jlong(long_at(index));
2501       break;
2502     case JVM_CONSTANT_Double :
2503       st->print("%lf", double_at(index));
2504       break;
2505     case JVM_CONSTANT_NameAndType :
2506       st->print("name_index=%d", name_ref_index_at(index));
2507       st->print(" signature_index=%d", signature_ref_index_at(index));
2508       break;
2509     case JVM_CONSTANT_Utf8 :
2510       symbol_at(index)->print_value_on(st);
2511       break;
2512     case JVM_CONSTANT_ClassIndex:
2513     case JVM_CONSTANT_ValueIndex: {
2514         int name_index = *int_at_addr(index);
2515         st->print("klass_index=%d ", name_index);
2516         symbol_at(name_index)->print_value_on(st);
2517       }
2518       break;
2519     case JVM_CONSTANT_UnresolvedClass :               // fall-through
2520     case JVM_CONSTANT_UnresolvedClassInError :
2521     case JVM_CONSTANT_UnresolvedValue :
2522     case JVM_CONSTANT_UnresolvedValueInError : {
2523         CPKlassSlot kslot = klass_slot_at(index);
2524         int resolved_klass_index = kslot.resolved_klass_index();
2525         int name_index = kslot.name_index();
2526         assert(tag_at(name_index).is_symbol(), "sanity");
2527 
2528         Klass* klass = resolved_klasses()->at(resolved_klass_index);
2529         if (klass != NULL) {
2530           klass->print_value_on(st);
2531         } else {
2532           symbol_at(name_index)->print_value_on(st);
2533         }
2534       }
2535       break;
2536     case JVM_CONSTANT_MethodHandle :
2537     case JVM_CONSTANT_MethodHandleInError :
2538       st->print("ref_kind=%d", method_handle_ref_kind_at(index));
2539       st->print(" ref_index=%d", method_handle_index_at(index));
2540       break;
2541     case JVM_CONSTANT_MethodType :
2542     case JVM_CONSTANT_MethodTypeInError :
2543       st->print("signature_index=%d", method_type_index_at(index));
2544       break;
2545     case JVM_CONSTANT_Dynamic :
2546     case JVM_CONSTANT_DynamicInError :
2547       {
2548         st->print("bootstrap_method_index=%d", invoke_dynamic_bootstrap_method_ref_index_at(index));
2549         st->print(" type_index=%d", invoke_dynamic_name_and_type_ref_index_at(index));
2550         int argc = invoke_dynamic_argument_count_at(index);
2551         if (argc > 0) {
2552           for (int arg_i = 0; arg_i < argc; arg_i++) {
2553             int arg = invoke_dynamic_argument_index_at(index, arg_i);
2554             st->print((arg_i == 0 ? " arguments={%d" : ", %d"), arg);
2555           }
2556           st->print("}");
2557         }
2558       }
2559       break;
2560     case JVM_CONSTANT_InvokeDynamic :
2561       {
2562         st->print("bootstrap_method_index=%d", invoke_dynamic_bootstrap_method_ref_index_at(index));
2563         st->print(" name_and_type_index=%d", invoke_dynamic_name_and_type_ref_index_at(index));
2564         int argc = invoke_dynamic_argument_count_at(index);
2565         if (argc > 0) {
2566           for (int arg_i = 0; arg_i < argc; arg_i++) {
2567             int arg = invoke_dynamic_argument_index_at(index, arg_i);
2568             st->print((arg_i == 0 ? " arguments={%d" : ", %d"), arg);
2569           }
2570           st->print("}");
2571         }
2572       }
2573       break;
2574     default:
2575       ShouldNotReachHere();
2576       break;
2577   }
2578   st->cr();
2579 }
2580 
2581 void ConstantPool::print_value_on(outputStream* st) const {
2582   assert(is_constantPool(), "must be constantPool");
2583   st->print("constant pool [%d]", length());
2584   if (has_preresolution()) st->print("/preresolution");
2585   if (operands() != NULL)  st->print("/operands[%d]", operands()->length());
2586   print_address_on(st);
2587   st->print(" for ");
2588   pool_holder()->print_value_on(st);
2589   if (pool_holder() != NULL) {
2590     bool extra = (pool_holder()->constants() != this);
2591     if (extra)  st->print(" (extra)");
2592   }
2593   if (cache() != NULL) {
2594     st->print(" cache=" PTR_FORMAT, p2i(cache()));
2595   }
2596 }
2597 
2598 #if INCLUDE_SERVICES
2599 // Size Statistics
2600 void ConstantPool::collect_statistics(KlassSizeStats *sz) const {
2601   sz->_cp_all_bytes += (sz->_cp_bytes          = sz->count(this));
2602   sz->_cp_all_bytes += (sz->_cp_tags_bytes     = sz->count_array(tags()));
2603   sz->_cp_all_bytes += (sz->_cp_cache_bytes    = sz->count(cache()));
2604   sz->_cp_all_bytes += (sz->_cp_operands_bytes = sz->count_array(operands()));
2605   sz->_cp_all_bytes += (sz->_cp_refmap_bytes   = sz->count_array(reference_map()));
2606 
2607   sz->_ro_bytes += sz->_cp_operands_bytes + sz->_cp_tags_bytes +
2608                    sz->_cp_refmap_bytes;
2609   sz->_rw_bytes += sz->_cp_bytes + sz->_cp_cache_bytes;
2610 }
2611 #endif // INCLUDE_SERVICES
2612 
2613 // Verification
2614 
2615 void ConstantPool::verify_on(outputStream* st) {
2616   guarantee(is_constantPool(), "object must be constant pool");
2617   for (int i = 0; i< length();  i++) {
2618     constantTag tag = tag_at(i);
2619     if (tag.is_klass() || tag.is_unresolved_klass() ||
2620         tag.is_value_type() || tag.is_unresolved_value_type()) {
2621       guarantee(klass_name_at(i)->refcount() != 0, "should have nonzero reference count");
2622     } else if (tag.is_symbol()) {
2623       CPSlot entry = slot_at(i);
2624       guarantee(entry.get_symbol()->refcount() != 0, "should have nonzero reference count");
2625     } else if (tag.is_string()) {
2626       CPSlot entry = slot_at(i);
2627       guarantee(entry.get_symbol()->refcount() != 0, "should have nonzero reference count");
2628     }
2629   }
2630   if (cache() != NULL) {
2631     // Note: cache() can be NULL before a class is completely setup or
2632     // in temporary constant pools used during constant pool merging
2633     guarantee(cache()->is_constantPoolCache(), "should be constant pool cache");
2634   }
2635   if (pool_holder() != NULL) {
2636     // Note: pool_holder() can be NULL in temporary constant pools
2637     // used during constant pool merging
2638     guarantee(pool_holder()->is_klass(),    "should be klass");
2639   }
2640 }
2641 
2642 
2643 void SymbolHashMap::add_entry(Symbol* sym, u2 value) {
2644   char *str = sym->as_utf8();
2645   unsigned int hash = compute_hash(str, sym->utf8_length());
2646   unsigned int index = hash % table_size();
2647 
2648   // check if already in map
2649   // we prefer the first entry since it is more likely to be what was used in
2650   // the class file
2651   for (SymbolHashMapEntry *en = bucket(index); en != NULL; en = en->next()) {
2652     assert(en->symbol() != NULL, "SymbolHashMapEntry symbol is NULL");
2653     if (en->hash() == hash && en->symbol() == sym) {
2654         return;  // already there
2655     }
2656   }
2657 
2658   SymbolHashMapEntry* entry = new SymbolHashMapEntry(hash, sym, value);
2659   entry->set_next(bucket(index));
2660   _buckets[index].set_entry(entry);
2661   assert(entry->symbol() != NULL, "SymbolHashMapEntry symbol is NULL");
2662 }
2663 
2664 SymbolHashMapEntry* SymbolHashMap::find_entry(Symbol* sym) {
2665   assert(sym != NULL, "SymbolHashMap::find_entry - symbol is NULL");
2666   char *str = sym->as_utf8();
2667   int   len = sym->utf8_length();
2668   unsigned int hash = SymbolHashMap::compute_hash(str, len);
2669   unsigned int index = hash % table_size();
2670   for (SymbolHashMapEntry *en = bucket(index); en != NULL; en = en->next()) {
2671     assert(en->symbol() != NULL, "SymbolHashMapEntry symbol is NULL");
2672     if (en->hash() == hash && en->symbol() == sym) {
2673       return en;
2674     }
2675   }
2676   return NULL;
2677 }
2678 
2679 void SymbolHashMap::initialize_table(int table_size) {
2680   _table_size = table_size;
2681   _buckets = NEW_C_HEAP_ARRAY(SymbolHashMapBucket, table_size, mtSymbol);
2682   for (int index = 0; index < table_size; index++) {
2683     _buckets[index].clear();
2684   }
2685 }