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