1 /*
   2  * Copyright (c) 1997, 2020, 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/bootstrapInfo.hpp"
  34 #include "interpreter/linkResolver.hpp"
  35 #include "logging/log.hpp"
  36 #include "logging/logStream.hpp"
  37 #include "memory/allocation.inline.hpp"
  38 #include "memory/heapShared.hpp"
  39 #include "memory/metadataFactory.hpp"
  40 #include "memory/metaspaceClosure.hpp"
  41 #include "memory/metaspaceShared.hpp"
  42 #include "memory/oopFactory.hpp"
  43 #include "memory/resourceArea.hpp"
  44 #include "memory/universe.hpp"
  45 #include "oops/array.hpp"
  46 #include "oops/constantPool.inline.hpp"
  47 #include "oops/cpCache.inline.hpp"
  48 #include "oops/instanceKlass.hpp"
  49 #include "oops/objArrayKlass.hpp"
  50 #include "oops/objArrayOop.inline.hpp"
  51 #include "oops/oop.inline.hpp"
  52 #include "oops/typeArrayOop.inline.hpp"
  53 #include "runtime/atomic.hpp"
  54 #include "runtime/handles.inline.hpp"
  55 #include "runtime/init.hpp"
  56 #include "runtime/javaCalls.hpp"
  57 #include "runtime/signature.hpp"
  58 #include "runtime/thread.inline.hpp"
  59 #include "runtime/vframe.inline.hpp"
  60 #include "utilities/copy.hpp"
  61 
  62 ConstantPool* ConstantPool::allocate(ClassLoaderData* loader_data, int length, TRAPS) {
  63   Array<u1>* tags = MetadataFactory::new_array<u1>(loader_data, length, 0, CHECK_NULL);
  64   int size = ConstantPool::size(length);
  65   return new (loader_data, size, MetaspaceObj::ConstantPoolType, THREAD) ConstantPool(tags);
  66 }
  67 
  68 void ConstantPool::copy_fields(const ConstantPool* orig) {
  69   // Preserve dynamic constant information from the original pool
  70   if (orig->has_dynamic_constant()) {
  71     set_has_dynamic_constant();
  72   }
  73 
  74   // Copy class version
  75   set_major_version(orig->major_version());
  76   set_minor_version(orig->minor_version());
  77 
  78   set_source_file_name_index(orig->source_file_name_index());
  79   set_generic_signature_index(orig->generic_signature_index());
  80 }
  81 
  82 #ifdef ASSERT
  83 
  84 // MetaspaceObj allocation invariant is calloc equivalent memory
  85 // simple verification of this here (JVM_CONSTANT_Invalid == 0 )
  86 static bool tag_array_is_zero_initialized(Array<u1>* tags) {
  87   assert(tags != NULL, "invariant");
  88   const int length = tags->length();
  89   for (int index = 0; index < length; ++index) {
  90     if (JVM_CONSTANT_Invalid != tags->at(index)) {
  91       return false;
  92     }
  93   }
  94   return true;
  95 }
  96 
  97 #endif
  98 
  99 ConstantPool::ConstantPool(Array<u1>* tags) :
 100   _tags(tags),
 101   _length(tags->length()) {
 102 
 103     assert(_tags != NULL, "invariant");
 104     assert(tags->length() == _length, "invariant");
 105     assert(tag_array_is_zero_initialized(tags), "invariant");
 106     assert(0 == flags(), "invariant");
 107     assert(0 == version(), "invariant");
 108     assert(NULL == _pool_holder, "invariant");
 109 }
 110 
 111 void ConstantPool::deallocate_contents(ClassLoaderData* loader_data) {
 112   if (cache() != NULL) {
 113     MetadataFactory::free_metadata(loader_data, cache());
 114     set_cache(NULL);
 115   }
 116 
 117   MetadataFactory::free_array<Klass*>(loader_data, resolved_klasses());
 118   set_resolved_klasses(NULL);
 119 
 120   MetadataFactory::free_array<jushort>(loader_data, operands());
 121   set_operands(NULL);
 122 
 123   release_C_heap_structures();
 124 
 125   // free tag array
 126   MetadataFactory::free_array<u1>(loader_data, tags());
 127   set_tags(NULL);
 128 }
 129 
 130 void ConstantPool::release_C_heap_structures() {
 131   // walk constant pool and decrement symbol reference counts
 132   unreference_symbols();
 133 }
 134 
 135 void ConstantPool::metaspace_pointers_do(MetaspaceClosure* it) {
 136   log_trace(cds)("Iter(ConstantPool): %p", this);
 137 
 138   it->push(&_tags, MetaspaceClosure::_writable);
 139   it->push(&_cache);
 140   it->push(&_pool_holder);
 141   it->push(&_operands);
 142   it->push(&_resolved_klasses, MetaspaceClosure::_writable);
 143 
 144   for (int i = 0; i < length(); i++) {
 145     // The only MSO's embedded in the CP entries are Symbols:
 146     //   JVM_CONSTANT_String (normal and pseudo)
 147     //   JVM_CONSTANT_Utf8
 148     constantTag ctag = tag_at(i);
 149     if (ctag.is_string() || ctag.is_utf8()) {
 150       it->push(symbol_at_addr(i));
 151     }
 152   }
 153 }
 154 
 155 objArrayOop ConstantPool::resolved_references() const {
 156   return (objArrayOop)_cache->resolved_references();
 157 }
 158 
 159 // Called from outside constant pool resolution where a resolved_reference array
 160 // may not be present.
 161 objArrayOop ConstantPool::resolved_references_or_null() const {
 162   if (_cache == NULL) {
 163     return NULL;
 164   } else {
 165     return (objArrayOop)_cache->resolved_references();
 166   }
 167 }
 168 
 169 // Create resolved_references array and mapping array for original cp indexes
 170 // The ldc bytecode was rewritten to have the resolved reference array index so need a way
 171 // to map it back for resolving and some unlikely miscellaneous uses.
 172 // The objects created by invokedynamic are appended to this list.
 173 void ConstantPool::initialize_resolved_references(ClassLoaderData* loader_data,
 174                                                   const intStack& reference_map,
 175                                                   int constant_pool_map_length,
 176                                                   TRAPS) {
 177   // Initialized the resolved object cache.
 178   int map_length = reference_map.length();
 179   if (map_length > 0) {
 180     // Only need mapping back to constant pool entries.  The map isn't used for
 181     // invokedynamic resolved_reference entries.  For invokedynamic entries,
 182     // the constant pool cache index has the mapping back to both the constant
 183     // pool and to the resolved reference index.
 184     if (constant_pool_map_length > 0) {
 185       Array<u2>* om = MetadataFactory::new_array<u2>(loader_data, constant_pool_map_length, CHECK);
 186 
 187       for (int i = 0; i < constant_pool_map_length; i++) {
 188         int x = reference_map.at(i);
 189         assert(x == (int)(jushort) x, "klass index is too big");
 190         om->at_put(i, (jushort)x);
 191       }
 192       set_reference_map(om);
 193     }
 194 
 195     // Create Java array for holding resolved strings, methodHandles,
 196     // methodTypes, invokedynamic and invokehandle appendix objects, etc.
 197     objArrayOop stom = oopFactory::new_objArray(SystemDictionary::Object_klass(), map_length, CHECK);
 198     Handle refs_handle (THREAD, (oop)stom);  // must handleize.
 199     set_resolved_references(loader_data->add_handle(refs_handle));
 200   }
 201 }
 202 
 203 void ConstantPool::allocate_resolved_klasses(ClassLoaderData* loader_data, int num_klasses, TRAPS) {
 204   // A ConstantPool can't possibly have 0xffff valid class entries,
 205   // because entry #0 must be CONSTANT_Invalid, and each class entry must refer to a UTF8
 206   // entry for the class's name. So at most we will have 0xfffe class entries.
 207   // This allows us to use 0xffff (ConstantPool::_temp_resolved_klass_index) to indicate
 208   // UnresolvedKlass entries that are temporarily created during class redefinition.
 209   assert(num_klasses < CPKlassSlot::_temp_resolved_klass_index, "sanity");
 210   assert(resolved_klasses() == NULL, "sanity");
 211   Array<Klass*>* rk = MetadataFactory::new_array<Klass*>(loader_data, num_klasses, CHECK);
 212   set_resolved_klasses(rk);
 213 }
 214 
 215 void ConstantPool::initialize_unresolved_klasses(ClassLoaderData* loader_data, TRAPS) {
 216   int len = length();
 217   int num_klasses = 0;
 218   for (int i = 1; i <len; i++) {
 219     switch (tag_at(i).value()) {
 220     case JVM_CONSTANT_ClassIndex:
 221       {
 222         const int class_index = klass_index_at(i);
 223         unresolved_klass_at_put(i, class_index, num_klasses++);
 224       }
 225       break;
 226 #ifndef PRODUCT
 227     case JVM_CONSTANT_Class:
 228     case JVM_CONSTANT_UnresolvedClass:
 229     case JVM_CONSTANT_UnresolvedClassInError:
 230       // All of these should have been reverted back to ClassIndex before calling
 231       // this function.
 232       ShouldNotReachHere();
 233 #endif
 234     }
 235   }
 236   allocate_resolved_klasses(loader_data, num_klasses, THREAD);
 237 }
 238 
 239 // Unsafe anonymous class support:
 240 void ConstantPool::klass_at_put(int class_index, int name_index, int resolved_klass_index, Klass* k, Symbol* name) {
 241   assert(is_within_bounds(class_index), "index out of bounds");
 242   assert(is_within_bounds(name_index), "index out of bounds");
 243   assert((resolved_klass_index & 0xffff0000) == 0, "must be");
 244   *int_at_addr(class_index) =
 245     build_int_from_shorts((jushort)resolved_klass_index, (jushort)name_index);
 246 
 247   symbol_at_put(name_index, name);
 248   name->increment_refcount();
 249   Klass** adr = resolved_klasses()->adr_at(resolved_klass_index);
 250   Atomic::release_store(adr, k);
 251 
 252   // The interpreter assumes when the tag is stored, the klass is resolved
 253   // and the Klass* non-NULL, so we need hardware store ordering here.
 254   if (k != NULL) {
 255     release_tag_at_put(class_index, JVM_CONSTANT_Class);
 256   } else {
 257     release_tag_at_put(class_index, JVM_CONSTANT_UnresolvedClass);
 258   }
 259 }
 260 
 261 // Unsafe anonymous class support:
 262 void ConstantPool::klass_at_put(int class_index, Klass* k) {
 263   assert(k != NULL, "must be valid klass");
 264   CPKlassSlot kslot = klass_slot_at(class_index);
 265   int resolved_klass_index = kslot.resolved_klass_index();
 266   Klass** adr = resolved_klasses()->adr_at(resolved_klass_index);
 267   Atomic::release_store(adr, k);
 268 
 269   // The interpreter assumes when the tag is stored, the klass is resolved
 270   // and the Klass* non-NULL, so we need hardware store ordering here.
 271   release_tag_at_put(class_index, JVM_CONSTANT_Class);
 272 }
 273 
 274 #if INCLUDE_CDS_JAVA_HEAP
 275 // Archive the resolved references
 276 void ConstantPool::archive_resolved_references(Thread* THREAD) {
 277   if (_cache == NULL) {
 278     return; // nothing to do
 279   }
 280 
 281   InstanceKlass *ik = pool_holder();
 282   if (!(ik->is_shared_boot_class() || ik->is_shared_platform_class() ||
 283         ik->is_shared_app_class())) {
 284     // Archiving resolved references for classes from non-builtin loaders
 285     // is not yet supported.
 286     return;
 287   }
 288 
 289   objArrayOop rr = resolved_references();
 290   Array<u2>* ref_map = reference_map();
 291   if (rr != NULL) {
 292     int ref_map_len = ref_map == NULL ? 0 : ref_map->length();
 293     int rr_len = rr->length();
 294     for (int i = 0; i < rr_len; i++) {
 295       oop obj = rr->obj_at(i);
 296       rr->obj_at_put(i, NULL);
 297       if (obj != NULL && i < ref_map_len) {
 298         int index = object_to_cp_index(i);
 299         if (tag_at(index).is_string()) {
 300           oop archived_string = HeapShared::find_archived_heap_object(obj);
 301           // Update the reference to point to the archived copy
 302           // of this string.
 303           // If the string is too large to archive, NULL is
 304           // stored into rr. At run time, string_at_impl() will create and intern
 305           // the string.
 306           rr->obj_at_put(i, archived_string);
 307         }
 308       }
 309     }
 310 
 311     oop archived = HeapShared::archive_heap_object(rr, THREAD);
 312     // If the resolved references array is not archived (too large),
 313     // the 'archived' object is NULL. No need to explicitly check
 314     // the return value of archive_heap_object here. At runtime, the
 315     // resolved references will be created using the normal process
 316     // when there is no archived value.
 317     _cache->set_archived_references(archived);
 318   }
 319 }
 320 
 321 void ConstantPool::resolve_class_constants(TRAPS) {
 322   assert(DumpSharedSpaces, "used during dump time only");
 323   // The _cache may be NULL if the _pool_holder klass fails verification
 324   // at dump time due to missing dependencies.
 325   if (cache() == NULL || reference_map() == NULL) {
 326     return; // nothing to do
 327   }
 328 
 329   constantPoolHandle cp(THREAD, this);
 330   for (int index = 1; index < length(); index++) { // Index 0 is unused
 331     if (tag_at(index).is_string() && !cp->is_pseudo_string_at(index)) {
 332       int cache_index = cp->cp_to_object_index(index);
 333       string_at_impl(cp, index, cache_index, CHECK);
 334     }
 335   }
 336 }
 337 
 338 void ConstantPool::add_dumped_interned_strings() {
 339   objArrayOop rr = resolved_references();
 340   if (rr != NULL) {
 341     int rr_len = rr->length();
 342     for (int i = 0; i < rr_len; i++) {
 343       oop p = rr->obj_at(i);
 344       if (java_lang_String::is_instance(p)) {
 345         HeapShared::add_to_dumped_interned_strings(p);
 346       }
 347     }
 348   }
 349 }
 350 #endif
 351 
 352 // CDS support. Create a new resolved_references array.
 353 void ConstantPool::restore_unshareable_info(TRAPS) {
 354   assert(is_constantPool(), "ensure C++ vtable is restored");
 355   assert(on_stack(), "should always be set for shared constant pools");
 356   assert(is_shared(), "should always be set for shared constant pools");
 357   assert(_cache != NULL, "constant pool _cache should not be NULL");
 358 
 359   // Only create the new resolved references array if it hasn't been attempted before
 360   if (resolved_references() != NULL) return;
 361 
 362   // restore the C++ vtable from the shared archive
 363   restore_vtable();
 364 
 365   if (SystemDictionary::Object_klass_loaded()) {
 366     ClassLoaderData* loader_data = pool_holder()->class_loader_data();
 367 #if INCLUDE_CDS_JAVA_HEAP
 368     if (HeapShared::open_archive_heap_region_mapped() &&
 369         _cache->archived_references() != NULL) {
 370       oop archived = _cache->archived_references();
 371       // Create handle for the archived resolved reference array object
 372       Handle refs_handle(THREAD, archived);
 373       set_resolved_references(loader_data->add_handle(refs_handle));
 374       _cache->clear_archived_references();
 375     } else
 376 #endif
 377     {
 378       // No mapped archived resolved reference array
 379       // Recreate the object array and add to ClassLoaderData.
 380       int map_length = resolved_reference_length();
 381       if (map_length > 0) {
 382         objArrayOop stom = oopFactory::new_objArray(SystemDictionary::Object_klass(), map_length, CHECK);
 383         Handle refs_handle(THREAD, (oop)stom);  // must handleize.
 384         set_resolved_references(loader_data->add_handle(refs_handle));
 385       }
 386     }
 387   }
 388 }
 389 
 390 void ConstantPool::remove_unshareable_info() {
 391   // Resolved references are not in the shared archive.
 392   // Save the length for restoration.  It is not necessarily the same length
 393   // as reference_map.length() if invokedynamic is saved. It is needed when
 394   // re-creating the resolved reference array if archived heap data cannot be map
 395   // at runtime.
 396   set_resolved_reference_length(
 397     resolved_references() != NULL ? resolved_references()->length() : 0);
 398   set_resolved_references(OopHandle());
 399 
 400   // Shared ConstantPools are in the RO region, so the _flags cannot be modified.
 401   // The _on_stack flag is used to prevent ConstantPools from deallocation during
 402   // class redefinition. Since shared ConstantPools cannot be deallocated anyway,
 403   // we always set _on_stack to true to avoid having to change _flags during runtime.
 404   _flags |= (_on_stack | _is_shared);
 405   int num_klasses = 0;
 406   for (int index = 1; index < length(); index++) { // Index 0 is unused
 407     if (!DynamicDumpSharedSpaces) {
 408       assert(!tag_at(index).is_unresolved_klass_in_error(), "This must not happen during static dump time");
 409     } else {
 410       if (tag_at(index).is_unresolved_klass_in_error() ||
 411           tag_at(index).is_method_handle_in_error()    ||
 412           tag_at(index).is_method_type_in_error()      ||
 413           tag_at(index).is_dynamic_constant_in_error()) {
 414         tag_at_put(index, JVM_CONSTANT_UnresolvedClass);
 415       }
 416     }
 417     if (tag_at(index).is_klass()) {
 418       // This class was resolved as a side effect of executing Java code
 419       // during dump time. We need to restore it back to an UnresolvedClass,
 420       // so that the proper class loading and initialization can happen
 421       // at runtime.
 422       bool clear_it = true;
 423       if (pool_holder()->is_hidden() && index == pool_holder()->this_class_index()) {
 424         // All references to a hidden class's own field/methods are through this
 425         // index. We cannot clear it. See comments in ClassFileParser::fill_instance_klass.
 426         clear_it = false;
 427       }
 428       if (clear_it) {
 429         CPKlassSlot kslot = klass_slot_at(index);
 430         int resolved_klass_index = kslot.resolved_klass_index();
 431         int name_index = kslot.name_index();
 432         assert(tag_at(name_index).is_symbol(), "sanity");
 433         resolved_klasses()->at_put(resolved_klass_index, NULL);
 434         tag_at_put(index, JVM_CONSTANT_UnresolvedClass);
 435         assert(klass_name_at(index) == symbol_at(name_index), "sanity");
 436       }
 437     }
 438   }
 439   if (cache() != NULL) {
 440     cache()->remove_unshareable_info();
 441   }
 442 }
 443 
 444 int ConstantPool::cp_to_object_index(int cp_index) {
 445   // this is harder don't do this so much.
 446   int i = reference_map()->find(cp_index);
 447   // We might not find the index for jsr292 call.
 448   return (i < 0) ? _no_index_sentinel : i;
 449 }
 450 
 451 void ConstantPool::string_at_put(int which, int obj_index, oop str) {
 452   resolved_references()->obj_at_put(obj_index, str);
 453 }
 454 
 455 void ConstantPool::trace_class_resolution(const constantPoolHandle& this_cp, Klass* k) {
 456   ResourceMark rm;
 457   int line_number = -1;
 458   const char * source_file = NULL;
 459   if (JavaThread::current()->has_last_Java_frame()) {
 460     // try to identify the method which called this function.
 461     vframeStream vfst(JavaThread::current());
 462     if (!vfst.at_end()) {
 463       line_number = vfst.method()->line_number_from_bci(vfst.bci());
 464       Symbol* s = vfst.method()->method_holder()->source_file_name();
 465       if (s != NULL) {
 466         source_file = s->as_C_string();
 467       }
 468     }
 469   }
 470   if (k != this_cp->pool_holder()) {
 471     // only print something if the classes are different
 472     if (source_file != NULL) {
 473       log_debug(class, resolve)("%s %s %s:%d",
 474                  this_cp->pool_holder()->external_name(),
 475                  k->external_name(), source_file, line_number);
 476     } else {
 477       log_debug(class, resolve)("%s %s",
 478                  this_cp->pool_holder()->external_name(),
 479                  k->external_name());
 480     }
 481   }
 482 }
 483 
 484 Klass* ConstantPool::klass_at_impl(const constantPoolHandle& this_cp, int which,
 485                                    bool save_resolution_error, TRAPS) {
 486   JavaThread* javaThread = THREAD->as_Java_thread();
 487 
 488   // A resolved constantPool entry will contain a Klass*, otherwise a Symbol*.
 489   // It is not safe to rely on the tag bit's here, since we don't have a lock, and
 490   // the entry and tag is not updated atomicly.
 491   CPKlassSlot kslot = this_cp->klass_slot_at(which);
 492   int resolved_klass_index = kslot.resolved_klass_index();
 493   int name_index = kslot.name_index();
 494   assert(this_cp->tag_at(name_index).is_symbol(), "sanity");
 495 
 496   Klass* klass = this_cp->resolved_klasses()->at(resolved_klass_index);
 497   if (klass != NULL) {
 498     return klass;
 499   }
 500 
 501   // This tag doesn't change back to unresolved class unless at a safepoint.
 502   if (this_cp->tag_at(which).is_unresolved_klass_in_error()) {
 503     // The original attempt to resolve this constant pool entry failed so find the
 504     // class of the original error and throw another error of the same class
 505     // (JVMS 5.4.3).
 506     // If there is a detail message, pass that detail message to the error.
 507     // The JVMS does not strictly require us to duplicate the same detail message,
 508     // or any internal exception fields such as cause or stacktrace.  But since the
 509     // detail message is often a class name or other literal string, we will repeat it
 510     // if we can find it in the symbol table.
 511     throw_resolution_error(this_cp, which, CHECK_NULL);
 512     ShouldNotReachHere();
 513   }
 514 
 515   Handle mirror_handle;
 516   Symbol* name = this_cp->symbol_at(name_index);
 517   Handle loader (THREAD, this_cp->pool_holder()->class_loader());
 518   Handle protection_domain (THREAD, this_cp->pool_holder()->protection_domain());
 519 
 520   Klass* k;
 521   {
 522     // Turn off the single stepping while doing class resolution
 523     JvmtiHideSingleStepping jhss(javaThread);
 524     k = SystemDictionary::resolve_or_fail(name, loader, protection_domain, true, THREAD);
 525   } //  JvmtiHideSingleStepping jhss(javaThread);
 526 
 527   if (!HAS_PENDING_EXCEPTION) {
 528     // preserve the resolved klass from unloading
 529     mirror_handle = Handle(THREAD, k->java_mirror());
 530     // Do access check for klasses
 531     verify_constant_pool_resolve(this_cp, k, THREAD);
 532   }
 533 
 534   // Failed to resolve class. We must record the errors so that subsequent attempts
 535   // to resolve this constant pool entry fail with the same error (JVMS 5.4.3).
 536   if (HAS_PENDING_EXCEPTION) {
 537     if (save_resolution_error) {
 538       save_and_throw_exception(this_cp, which, constantTag(JVM_CONSTANT_UnresolvedClass), CHECK_NULL);
 539       // If CHECK_NULL above doesn't return the exception, that means that
 540       // some other thread has beaten us and has resolved the class.
 541       // To preserve old behavior, we return the resolved class.
 542       klass = this_cp->resolved_klasses()->at(resolved_klass_index);
 543       assert(klass != NULL, "must be resolved if exception was cleared");
 544       return klass;
 545     } else {
 546       return NULL;  // return the pending exception
 547     }
 548   }
 549 
 550   // logging for class+resolve.
 551   if (log_is_enabled(Debug, class, resolve)){
 552     trace_class_resolution(this_cp, k);
 553   }
 554   Klass** adr = this_cp->resolved_klasses()->adr_at(resolved_klass_index);
 555   Atomic::release_store(adr, k);
 556   // The interpreter assumes when the tag is stored, the klass is resolved
 557   // and the Klass* stored in _resolved_klasses is non-NULL, so we need
 558   // hardware store ordering here.
 559   this_cp->release_tag_at_put(which, JVM_CONSTANT_Class);
 560   return k;
 561 }
 562 
 563 
 564 // Does not update ConstantPool* - to avoid any exception throwing. Used
 565 // by compiler and exception handling.  Also used to avoid classloads for
 566 // instanceof operations. Returns NULL if the class has not been loaded or
 567 // if the verification of constant pool failed
 568 Klass* ConstantPool::klass_at_if_loaded(const constantPoolHandle& this_cp, int which) {
 569   CPKlassSlot kslot = this_cp->klass_slot_at(which);
 570   int resolved_klass_index = kslot.resolved_klass_index();
 571   int name_index = kslot.name_index();
 572   assert(this_cp->tag_at(name_index).is_symbol(), "sanity");
 573 
 574   Klass* k = this_cp->resolved_klasses()->at(resolved_klass_index);
 575   if (k != NULL) {
 576     return k;
 577   } else {
 578     Thread *thread = Thread::current();
 579     Symbol* name = this_cp->symbol_at(name_index);
 580     oop loader = this_cp->pool_holder()->class_loader();
 581     oop protection_domain = this_cp->pool_holder()->protection_domain();
 582     Handle h_prot (thread, protection_domain);
 583     Handle h_loader (thread, loader);
 584     Klass* k = SystemDictionary::find(name, h_loader, h_prot, thread);
 585 
 586     // Avoid constant pool verification at a safepoint, which takes the Module_lock.
 587     if (k != NULL && !SafepointSynchronize::is_at_safepoint()) {
 588       // Make sure that resolving is legal
 589       EXCEPTION_MARK;
 590       // return NULL if verification fails
 591       verify_constant_pool_resolve(this_cp, k, THREAD);
 592       if (HAS_PENDING_EXCEPTION) {
 593         CLEAR_PENDING_EXCEPTION;
 594         return NULL;
 595       }
 596       return k;
 597     } else {
 598       return k;
 599     }
 600   }
 601 }
 602 
 603 Method* ConstantPool::method_at_if_loaded(const constantPoolHandle& cpool,
 604                                                    int which) {
 605   if (cpool->cache() == NULL)  return NULL;  // nothing to load yet
 606   int cache_index = decode_cpcache_index(which, true);
 607   if (!(cache_index >= 0 && cache_index < cpool->cache()->length())) {
 608     // FIXME: should be an assert
 609     log_debug(class, resolve)("bad operand %d in:", which); cpool->print();
 610     return NULL;
 611   }
 612   ConstantPoolCacheEntry* e = cpool->cache()->entry_at(cache_index);
 613   return e->method_if_resolved(cpool);
 614 }
 615 
 616 
 617 bool ConstantPool::has_appendix_at_if_loaded(const constantPoolHandle& cpool, int which) {
 618   if (cpool->cache() == NULL)  return false;  // nothing to load yet
 619   int cache_index = decode_cpcache_index(which, true);
 620   ConstantPoolCacheEntry* e = cpool->cache()->entry_at(cache_index);
 621   return e->has_appendix();
 622 }
 623 
 624 oop ConstantPool::appendix_at_if_loaded(const constantPoolHandle& cpool, int which) {
 625   if (cpool->cache() == NULL)  return NULL;  // nothing to load yet
 626   int cache_index = decode_cpcache_index(which, true);
 627   ConstantPoolCacheEntry* e = cpool->cache()->entry_at(cache_index);
 628   return e->appendix_if_resolved(cpool);
 629 }
 630 
 631 
 632 bool ConstantPool::has_local_signature_at_if_loaded(const constantPoolHandle& cpool, int which) {
 633   if (cpool->cache() == NULL)  return false;  // nothing to load yet
 634   int cache_index = decode_cpcache_index(which, true);
 635   ConstantPoolCacheEntry* e = cpool->cache()->entry_at(cache_index);
 636   return e->has_local_signature();
 637 }
 638 
 639 Symbol* ConstantPool::impl_name_ref_at(int which, bool uncached) {
 640   int name_index = name_ref_index_at(impl_name_and_type_ref_index_at(which, uncached));
 641   return symbol_at(name_index);
 642 }
 643 
 644 
 645 Symbol* ConstantPool::impl_signature_ref_at(int which, bool uncached) {
 646   int signature_index = signature_ref_index_at(impl_name_and_type_ref_index_at(which, uncached));
 647   return symbol_at(signature_index);
 648 }
 649 
 650 int ConstantPool::impl_name_and_type_ref_index_at(int which, bool uncached) {
 651   int i = which;
 652   if (!uncached && cache() != NULL) {
 653     if (ConstantPool::is_invokedynamic_index(which)) {
 654       // Invokedynamic index is index into the constant pool cache
 655       int pool_index = invokedynamic_bootstrap_ref_index_at(which);
 656       pool_index = bootstrap_name_and_type_ref_index_at(pool_index);
 657       assert(tag_at(pool_index).is_name_and_type(), "");
 658       return pool_index;
 659     }
 660     // change byte-ordering and go via cache
 661     i = remap_instruction_operand_from_cache(which);
 662   } else {
 663     if (tag_at(which).has_bootstrap()) {
 664       int pool_index = bootstrap_name_and_type_ref_index_at(which);
 665       assert(tag_at(pool_index).is_name_and_type(), "");
 666       return pool_index;
 667     }
 668   }
 669   assert(tag_at(i).is_field_or_method(), "Corrupted constant pool");
 670   assert(!tag_at(i).has_bootstrap(), "Must be handled above");
 671   jint ref_index = *int_at_addr(i);
 672   return extract_high_short_from_int(ref_index);
 673 }
 674 
 675 constantTag ConstantPool::impl_tag_ref_at(int which, bool uncached) {
 676   int pool_index = which;
 677   if (!uncached && cache() != NULL) {
 678     if (ConstantPool::is_invokedynamic_index(which)) {
 679       // Invokedynamic index is index into resolved_references
 680       pool_index = invokedynamic_bootstrap_ref_index_at(which);
 681     } else {
 682       // change byte-ordering and go via cache
 683       pool_index = remap_instruction_operand_from_cache(which);
 684     }
 685   }
 686   return tag_at(pool_index);
 687 }
 688 
 689 int ConstantPool::impl_klass_ref_index_at(int which, bool uncached) {
 690   guarantee(!ConstantPool::is_invokedynamic_index(which),
 691             "an invokedynamic instruction does not have a klass");
 692   int i = which;
 693   if (!uncached && cache() != NULL) {
 694     // change byte-ordering and go via cache
 695     i = remap_instruction_operand_from_cache(which);
 696   }
 697   assert(tag_at(i).is_field_or_method(), "Corrupted constant pool");
 698   jint ref_index = *int_at_addr(i);
 699   return extract_low_short_from_int(ref_index);
 700 }
 701 
 702 
 703 
 704 int ConstantPool::remap_instruction_operand_from_cache(int operand) {
 705   int cpc_index = operand;
 706   DEBUG_ONLY(cpc_index -= CPCACHE_INDEX_TAG);
 707   assert((int)(u2)cpc_index == cpc_index, "clean u2");
 708   int member_index = cache()->entry_at(cpc_index)->constant_pool_index();
 709   return member_index;
 710 }
 711 
 712 
 713 void ConstantPool::verify_constant_pool_resolve(const constantPoolHandle& this_cp, Klass* k, TRAPS) {
 714   if (!(k->is_instance_klass() || k->is_objArray_klass())) {
 715     return;  // short cut, typeArray klass is always accessible
 716   }
 717   Klass* holder = this_cp->pool_holder();
 718   LinkResolver::check_klass_accessibility(holder, k, CHECK);
 719 }
 720 
 721 
 722 int ConstantPool::name_ref_index_at(int which_nt) {
 723   jint ref_index = name_and_type_at(which_nt);
 724   return extract_low_short_from_int(ref_index);
 725 }
 726 
 727 
 728 int ConstantPool::signature_ref_index_at(int which_nt) {
 729   jint ref_index = name_and_type_at(which_nt);
 730   return extract_high_short_from_int(ref_index);
 731 }
 732 
 733 
 734 Klass* ConstantPool::klass_ref_at(int which, TRAPS) {
 735   return klass_at(klass_ref_index_at(which), THREAD);
 736 }
 737 
 738 Symbol* ConstantPool::klass_name_at(int which) const {
 739   return symbol_at(klass_slot_at(which).name_index());
 740 }
 741 
 742 Symbol* ConstantPool::klass_ref_at_noresolve(int which) {
 743   jint ref_index = klass_ref_index_at(which);
 744   return klass_at_noresolve(ref_index);
 745 }
 746 
 747 Symbol* ConstantPool::uncached_klass_ref_at_noresolve(int which) {
 748   jint ref_index = uncached_klass_ref_index_at(which);
 749   return klass_at_noresolve(ref_index);
 750 }
 751 
 752 char* ConstantPool::string_at_noresolve(int which) {
 753   return unresolved_string_at(which)->as_C_string();
 754 }
 755 
 756 BasicType ConstantPool::basic_type_for_signature_at(int which) const {
 757   return Signature::basic_type(symbol_at(which));
 758 }
 759 
 760 
 761 void ConstantPool::resolve_string_constants_impl(const constantPoolHandle& this_cp, TRAPS) {
 762   for (int index = 1; index < this_cp->length(); index++) { // Index 0 is unused
 763     if (this_cp->tag_at(index).is_string()) {
 764       this_cp->string_at(index, CHECK);
 765     }
 766   }
 767 }
 768 
 769 Symbol* ConstantPool::exception_message(const constantPoolHandle& this_cp, int which, constantTag tag, oop pending_exception) {
 770   // Dig out the detailed message to reuse if possible
 771   Symbol* message = java_lang_Throwable::detail_message(pending_exception);
 772   if (message != NULL) {
 773     return message;
 774   }
 775 
 776   // Return specific message for the tag
 777   switch (tag.value()) {
 778   case JVM_CONSTANT_UnresolvedClass:
 779     // return the class name in the error message
 780     message = this_cp->klass_name_at(which);
 781     break;
 782   case JVM_CONSTANT_MethodHandle:
 783     // return the method handle name in the error message
 784     message = this_cp->method_handle_name_ref_at(which);
 785     break;
 786   case JVM_CONSTANT_MethodType:
 787     // return the method type signature in the error message
 788     message = this_cp->method_type_signature_at(which);
 789     break;
 790   case JVM_CONSTANT_Dynamic:
 791     // return the name of the condy in the error message
 792     message = this_cp->uncached_name_ref_at(which);
 793     break;
 794   default:
 795     ShouldNotReachHere();
 796   }
 797 
 798   return message;
 799 }
 800 
 801 void ConstantPool::throw_resolution_error(const constantPoolHandle& this_cp, int which, TRAPS) {
 802   Symbol* message = NULL;
 803   Symbol* error = SystemDictionary::find_resolution_error(this_cp, which, &message);
 804   assert(error != NULL, "checking");
 805   CLEAR_PENDING_EXCEPTION;
 806   if (message != NULL) {
 807     ResourceMark rm;
 808     THROW_MSG(error, message->as_C_string());
 809   } else {
 810     THROW(error);
 811   }
 812 }
 813 
 814 // If resolution for Class, Dynamic constant, MethodHandle or MethodType fails, save the
 815 // exception in the resolution error table, so that the same exception is thrown again.
 816 void ConstantPool::save_and_throw_exception(const constantPoolHandle& this_cp, int which,
 817                                             constantTag tag, TRAPS) {
 818   Symbol* error = PENDING_EXCEPTION->klass()->name();
 819 
 820   int error_tag = tag.error_value();
 821 
 822   if (!PENDING_EXCEPTION->
 823     is_a(SystemDictionary::LinkageError_klass())) {
 824     // Just throw the exception and don't prevent these classes from
 825     // being loaded due to virtual machine errors like StackOverflow
 826     // and OutOfMemoryError, etc, or if the thread was hit by stop()
 827     // Needs clarification to section 5.4.3 of the VM spec (see 6308271)
 828   } else if (this_cp->tag_at(which).value() != error_tag) {
 829     Symbol* message = exception_message(this_cp, which, tag, PENDING_EXCEPTION);
 830     SystemDictionary::add_resolution_error(this_cp, which, error, message);
 831     // CAS in the tag.  If a thread beat us to registering this error that's fine.
 832     // If another thread resolved the reference, this is a race condition. This
 833     // thread may have had a security manager or something temporary.
 834     // This doesn't deterministically get an error.   So why do we save this?
 835     // We save this because jvmti can add classes to the bootclass path after
 836     // this error, so it needs to get the same error if the error is first.
 837     jbyte old_tag = Atomic::cmpxchg((jbyte*)this_cp->tag_addr_at(which),
 838                                     (jbyte)tag.value(),
 839                                     (jbyte)error_tag);
 840     if (old_tag != error_tag && old_tag != tag.value()) {
 841       // MethodHandles and MethodType doesn't change to resolved version.
 842       assert(this_cp->tag_at(which).is_klass(), "Wrong tag value");
 843       // Forget the exception and use the resolved class.
 844       CLEAR_PENDING_EXCEPTION;
 845     }
 846   } else {
 847     // some other thread put this in error state
 848     throw_resolution_error(this_cp, which, CHECK);
 849   }
 850 }
 851 
 852 constantTag ConstantPool::constant_tag_at(int which) {
 853   constantTag tag = tag_at(which);
 854   if (tag.is_dynamic_constant() ||
 855       tag.is_dynamic_constant_in_error()) {
 856     BasicType bt = basic_type_for_constant_at(which);
 857     // dynamic constant could return an array, treat as object
 858     return constantTag::ofBasicType(is_reference_type(bt) ? T_OBJECT : bt);
 859   }
 860   return tag;
 861 }
 862 
 863 BasicType ConstantPool::basic_type_for_constant_at(int which) {
 864   constantTag tag = tag_at(which);
 865   if (tag.is_dynamic_constant() ||
 866       tag.is_dynamic_constant_in_error()) {
 867     // have to look at the signature for this one
 868     Symbol* constant_type = uncached_signature_ref_at(which);
 869     return Signature::basic_type(constant_type);
 870   }
 871   return tag.basic_type();
 872 }
 873 
 874 // Called to resolve constants in the constant pool and return an oop.
 875 // Some constant pool entries cache their resolved oop. This is also
 876 // called to create oops from constants to use in arguments for invokedynamic
 877 oop ConstantPool::resolve_constant_at_impl(const constantPoolHandle& this_cp,
 878                                            int index, int cache_index,
 879                                            bool* status_return, TRAPS) {
 880   oop result_oop = NULL;
 881   Handle throw_exception;
 882 
 883   if (cache_index == _possible_index_sentinel) {
 884     // It is possible that this constant is one which is cached in the objects.
 885     // We'll do a linear search.  This should be OK because this usage is rare.
 886     // FIXME: If bootstrap specifiers stress this code, consider putting in
 887     // a reverse index.  Binary search over a short array should do it.
 888     assert(index > 0, "valid index");
 889     cache_index = this_cp->cp_to_object_index(index);
 890   }
 891   assert(cache_index == _no_index_sentinel || cache_index >= 0, "");
 892   assert(index == _no_index_sentinel || index >= 0, "");
 893 
 894   if (cache_index >= 0) {
 895     result_oop = this_cp->resolved_references()->obj_at(cache_index);
 896     if (result_oop != NULL) {
 897       if (result_oop == Universe::the_null_sentinel()) {
 898         DEBUG_ONLY(int temp_index = (index >= 0 ? index : this_cp->object_to_cp_index(cache_index)));
 899         assert(this_cp->tag_at(temp_index).is_dynamic_constant(), "only condy uses the null sentinel");
 900         result_oop = NULL;
 901       }
 902       if (status_return != NULL)  (*status_return) = true;
 903       return result_oop;
 904       // That was easy...
 905     }
 906     index = this_cp->object_to_cp_index(cache_index);
 907   }
 908 
 909   jvalue prim_value;  // temp used only in a few cases below
 910 
 911   constantTag tag = this_cp->tag_at(index);
 912 
 913   if (status_return != NULL) {
 914     // don't trigger resolution if the constant might need it
 915     switch (tag.value()) {
 916     case JVM_CONSTANT_Class:
 917     {
 918       CPKlassSlot kslot = this_cp->klass_slot_at(index);
 919       int resolved_klass_index = kslot.resolved_klass_index();
 920       if (this_cp->resolved_klasses()->at(resolved_klass_index) == NULL) {
 921         (*status_return) = false;
 922         return NULL;
 923       }
 924       // the klass is waiting in the CP; go get it
 925       break;
 926     }
 927     case JVM_CONSTANT_String:
 928     case JVM_CONSTANT_Integer:
 929     case JVM_CONSTANT_Float:
 930     case JVM_CONSTANT_Long:
 931     case JVM_CONSTANT_Double:
 932       // these guys trigger OOM at worst
 933       break;
 934     default:
 935       (*status_return) = false;
 936       return NULL;
 937     }
 938     // from now on there is either success or an OOME
 939     (*status_return) = true;
 940   }
 941 
 942   switch (tag.value()) {
 943 
 944   case JVM_CONSTANT_UnresolvedClass:
 945   case JVM_CONSTANT_UnresolvedClassInError:
 946   case JVM_CONSTANT_Class:
 947     {
 948       assert(cache_index == _no_index_sentinel, "should not have been set");
 949       Klass* resolved = klass_at_impl(this_cp, index, true, CHECK_NULL);
 950       // ldc wants the java mirror.
 951       result_oop = resolved->java_mirror();
 952       break;
 953     }
 954 
 955   case JVM_CONSTANT_Dynamic:
 956     {
 957       // Resolve the Dynamically-Computed constant to invoke the BSM in order to obtain the resulting oop.
 958       BootstrapInfo bootstrap_specifier(this_cp, index);
 959 
 960       // The initial step in resolving an unresolved symbolic reference to a
 961       // dynamically-computed constant is to resolve the symbolic reference to a
 962       // method handle which will be the bootstrap method for the dynamically-computed
 963       // constant. If resolution of the java.lang.invoke.MethodHandle for the bootstrap
 964       // method fails, then a MethodHandleInError is stored at the corresponding
 965       // bootstrap method's CP index for the CONSTANT_MethodHandle_info. No need to
 966       // set a DynamicConstantInError here since any subsequent use of this
 967       // bootstrap method will encounter the resolution of MethodHandleInError.
 968       // Both the first, (resolution of the BSM and its static arguments), and the second tasks,
 969       // (invocation of the BSM), of JVMS Section 5.4.3.6 occur within invoke_bootstrap_method()
 970       // for the bootstrap_specifier created above.
 971       SystemDictionary::invoke_bootstrap_method(bootstrap_specifier, THREAD);
 972       Exceptions::wrap_dynamic_exception(/* is_indy */ false, THREAD);
 973       if (HAS_PENDING_EXCEPTION) {
 974         // Resolution failure of the dynamically-computed constant, save_and_throw_exception
 975         // will check for a LinkageError and store a DynamicConstantInError.
 976         save_and_throw_exception(this_cp, index, tag, CHECK_NULL);
 977       }
 978       result_oop = bootstrap_specifier.resolved_value()();
 979       BasicType type = Signature::basic_type(bootstrap_specifier.signature());
 980       if (!is_reference_type(type)) {
 981         // Make sure the primitive value is properly boxed.
 982         // This is a JDK responsibility.
 983         const char* fail = NULL;
 984         if (result_oop == NULL) {
 985           fail = "null result instead of box";
 986         } else if (!is_java_primitive(type)) {
 987           // FIXME: support value types via unboxing
 988           fail = "can only handle references and primitives";
 989         } else if (!java_lang_boxing_object::is_instance(result_oop, type)) {
 990           fail = "primitive is not properly boxed";
 991         }
 992         if (fail != NULL) {
 993           // Since this exception is not a LinkageError, throw exception
 994           // but do not save a DynamicInError resolution result.
 995           // See section 5.4.3 of the VM spec.
 996           THROW_MSG_NULL(vmSymbols::java_lang_InternalError(), fail);
 997         }
 998       }
 999 
1000       LogTarget(Debug, methodhandles, condy) lt_condy;
1001       if (lt_condy.is_enabled()) {
1002         LogStream ls(lt_condy);
1003         bootstrap_specifier.print_msg_on(&ls, "resolve_constant_at_impl");
1004       }
1005       break;
1006     }
1007 
1008   case JVM_CONSTANT_String:
1009     assert(cache_index != _no_index_sentinel, "should have been set");
1010     if (this_cp->is_pseudo_string_at(index)) {
1011       result_oop = this_cp->pseudo_string_at(index, cache_index);
1012       break;
1013     }
1014     result_oop = string_at_impl(this_cp, index, cache_index, CHECK_NULL);
1015     break;
1016 
1017   case JVM_CONSTANT_DynamicInError:
1018   case JVM_CONSTANT_MethodHandleInError:
1019   case JVM_CONSTANT_MethodTypeInError:
1020     {
1021       throw_resolution_error(this_cp, index, CHECK_NULL);
1022       break;
1023     }
1024 
1025   case JVM_CONSTANT_MethodHandle:
1026     {
1027       int ref_kind                 = this_cp->method_handle_ref_kind_at(index);
1028       int callee_index             = this_cp->method_handle_klass_index_at(index);
1029       Symbol*  name =      this_cp->method_handle_name_ref_at(index);
1030       Symbol*  signature = this_cp->method_handle_signature_ref_at(index);
1031       constantTag m_tag  = this_cp->tag_at(this_cp->method_handle_index_at(index));
1032       { ResourceMark rm(THREAD);
1033         log_debug(class, resolve)("resolve JVM_CONSTANT_MethodHandle:%d [%d/%d/%d] %s.%s",
1034                               ref_kind, index, this_cp->method_handle_index_at(index),
1035                               callee_index, name->as_C_string(), signature->as_C_string());
1036       }
1037 
1038       Klass* callee = klass_at_impl(this_cp, callee_index, true, CHECK_NULL);
1039 
1040       // Check constant pool method consistency
1041       if ((callee->is_interface() && m_tag.is_method()) ||
1042           ((!callee->is_interface() && m_tag.is_interface_method()))) {
1043         ResourceMark rm(THREAD);
1044         stringStream ss;
1045         ss.print("Inconsistent constant pool data in classfile for class %s. "
1046                  "Method '", callee->name()->as_C_string());
1047         signature->print_as_signature_external_return_type(&ss);
1048         ss.print(" %s(", name->as_C_string());
1049         signature->print_as_signature_external_parameters(&ss);
1050         ss.print(")' at index %d is %s and should be %s",
1051                  index,
1052                  callee->is_interface() ? "CONSTANT_MethodRef" : "CONSTANT_InterfaceMethodRef",
1053                  callee->is_interface() ? "CONSTANT_InterfaceMethodRef" : "CONSTANT_MethodRef");
1054         THROW_MSG_NULL(vmSymbols::java_lang_IncompatibleClassChangeError(), ss.as_string());
1055       }
1056 
1057       Klass* klass = this_cp->pool_holder();
1058       Handle value = SystemDictionary::link_method_handle_constant(klass, ref_kind,
1059                                                                    callee, name, signature,
1060                                                                    THREAD);
1061       result_oop = value();
1062       if (HAS_PENDING_EXCEPTION) {
1063         save_and_throw_exception(this_cp, index, tag, CHECK_NULL);
1064       }
1065       break;
1066     }
1067 
1068   case JVM_CONSTANT_MethodType:
1069     {
1070       Symbol*  signature = this_cp->method_type_signature_at(index);
1071       { ResourceMark rm(THREAD);
1072         log_debug(class, resolve)("resolve JVM_CONSTANT_MethodType [%d/%d] %s",
1073                               index, this_cp->method_type_index_at(index),
1074                               signature->as_C_string());
1075       }
1076       Klass* klass = this_cp->pool_holder();
1077       Handle value = SystemDictionary::find_method_handle_type(signature, klass, THREAD);
1078       result_oop = value();
1079       if (HAS_PENDING_EXCEPTION) {
1080         save_and_throw_exception(this_cp, index, tag, CHECK_NULL);
1081       }
1082       break;
1083     }
1084 
1085   case JVM_CONSTANT_Integer:
1086     assert(cache_index == _no_index_sentinel, "should not have been set");
1087     prim_value.i = this_cp->int_at(index);
1088     result_oop = java_lang_boxing_object::create(T_INT, &prim_value, CHECK_NULL);
1089     break;
1090 
1091   case JVM_CONSTANT_Float:
1092     assert(cache_index == _no_index_sentinel, "should not have been set");
1093     prim_value.f = this_cp->float_at(index);
1094     result_oop = java_lang_boxing_object::create(T_FLOAT, &prim_value, CHECK_NULL);
1095     break;
1096 
1097   case JVM_CONSTANT_Long:
1098     assert(cache_index == _no_index_sentinel, "should not have been set");
1099     prim_value.j = this_cp->long_at(index);
1100     result_oop = java_lang_boxing_object::create(T_LONG, &prim_value, CHECK_NULL);
1101     break;
1102 
1103   case JVM_CONSTANT_Double:
1104     assert(cache_index == _no_index_sentinel, "should not have been set");
1105     prim_value.d = this_cp->double_at(index);
1106     result_oop = java_lang_boxing_object::create(T_DOUBLE, &prim_value, CHECK_NULL);
1107     break;
1108 
1109   default:
1110     DEBUG_ONLY( tty->print_cr("*** %p: tag at CP[%d/%d] = %d",
1111                               this_cp(), index, cache_index, tag.value()));
1112     assert(false, "unexpected constant tag");
1113     break;
1114   }
1115 
1116   if (cache_index >= 0) {
1117     // Benign race condition:  resolved_references may already be filled in.
1118     // The important thing here is that all threads pick up the same result.
1119     // It doesn't matter which racing thread wins, as long as only one
1120     // result is used by all threads, and all future queries.
1121     oop new_result = (result_oop == NULL ? Universe::the_null_sentinel() : result_oop);
1122     oop old_result = this_cp->resolved_references()
1123       ->atomic_compare_exchange_oop(cache_index, new_result, NULL);
1124     if (old_result == NULL) {
1125       return result_oop;  // was installed
1126     } else {
1127       // Return the winning thread's result.  This can be different than
1128       // the result here for MethodHandles.
1129       if (old_result == Universe::the_null_sentinel())
1130         old_result = NULL;
1131       return old_result;
1132     }
1133   } else {
1134     assert(result_oop != Universe::the_null_sentinel(), "");
1135     return result_oop;
1136   }
1137 }
1138 
1139 oop ConstantPool::uncached_string_at(int which, TRAPS) {
1140   Symbol* sym = unresolved_string_at(which);
1141   oop str = StringTable::intern(sym, CHECK_(NULL));
1142   assert(java_lang_String::is_instance(str), "must be string");
1143   return str;
1144 }
1145 
1146 void ConstantPool::copy_bootstrap_arguments_at_impl(const constantPoolHandle& this_cp, int index,
1147                                                     int start_arg, int end_arg,
1148                                                     objArrayHandle info, int pos,
1149                                                     bool must_resolve, Handle if_not_available,
1150                                                     TRAPS) {
1151   int argc;
1152   int limit = pos + end_arg - start_arg;
1153   // checks: index in range [0..this_cp->length),
1154   // tag at index, start..end in range [0..argc],
1155   // info array non-null, pos..limit in [0..info.length]
1156   if ((0 >= index    || index >= this_cp->length())  ||
1157       !(this_cp->tag_at(index).is_invoke_dynamic()    ||
1158         this_cp->tag_at(index).is_dynamic_constant()) ||
1159       (0 > start_arg || start_arg > end_arg) ||
1160       (end_arg > (argc = this_cp->bootstrap_argument_count_at(index))) ||
1161       (0 > pos       || pos > limit)         ||
1162       (info.is_null() || limit > info->length())) {
1163     // An index or something else went wrong; throw an error.
1164     // Since this is an internal API, we don't expect this,
1165     // so we don't bother to craft a nice message.
1166     THROW_MSG(vmSymbols::java_lang_LinkageError(), "bad BSM argument access");
1167   }
1168   // now we can loop safely
1169   int info_i = pos;
1170   for (int i = start_arg; i < end_arg; i++) {
1171     int arg_index = this_cp->bootstrap_argument_index_at(index, i);
1172     oop arg_oop;
1173     if (must_resolve) {
1174       arg_oop = this_cp->resolve_possibly_cached_constant_at(arg_index, CHECK);
1175     } else {
1176       bool found_it = false;
1177       arg_oop = this_cp->find_cached_constant_at(arg_index, found_it, CHECK);
1178       if (!found_it)  arg_oop = if_not_available();
1179     }
1180     info->obj_at_put(info_i++, arg_oop);
1181   }
1182 }
1183 
1184 oop ConstantPool::string_at_impl(const constantPoolHandle& this_cp, int which, int obj_index, TRAPS) {
1185   // If the string has already been interned, this entry will be non-null
1186   oop str = this_cp->resolved_references()->obj_at(obj_index);
1187   assert(str != Universe::the_null_sentinel(), "");
1188   if (str != NULL) return str;
1189   Symbol* sym = this_cp->unresolved_string_at(which);
1190   str = StringTable::intern(sym, CHECK_(NULL));
1191   this_cp->string_at_put(which, obj_index, str);
1192   assert(java_lang_String::is_instance(str), "must be string");
1193   return str;
1194 }
1195 
1196 
1197 bool ConstantPool::klass_name_at_matches(const InstanceKlass* k, int which) {
1198   // Names are interned, so we can compare Symbol*s directly
1199   Symbol* cp_name = klass_name_at(which);
1200   return (cp_name == k->name());
1201 }
1202 
1203 
1204 // Iterate over symbols and decrement ones which are Symbol*s
1205 // This is done during GC.
1206 // Only decrement the UTF8 symbols. Strings point to
1207 // these symbols but didn't increment the reference count.
1208 void ConstantPool::unreference_symbols() {
1209   for (int index = 1; index < length(); index++) { // Index 0 is unused
1210     constantTag tag = tag_at(index);
1211     if (tag.is_symbol()) {
1212       symbol_at(index)->decrement_refcount();
1213     }
1214   }
1215 }
1216 
1217 
1218 // Compare this constant pool's entry at index1 to the constant pool
1219 // cp2's entry at index2.
1220 bool ConstantPool::compare_entry_to(int index1, const constantPoolHandle& cp2,
1221        int index2, TRAPS) {
1222 
1223   // The error tags are equivalent to non-error tags when comparing
1224   jbyte t1 = tag_at(index1).non_error_value();
1225   jbyte t2 = cp2->tag_at(index2).non_error_value();
1226 
1227   if (t1 != t2) {
1228     // Not the same entry type so there is nothing else to check. Note
1229     // that this style of checking will consider resolved/unresolved
1230     // class pairs as different.
1231     // From the ConstantPool* API point of view, this is correct
1232     // behavior. See VM_RedefineClasses::merge_constant_pools() to see how this
1233     // plays out in the context of ConstantPool* merging.
1234     return false;
1235   }
1236 
1237   switch (t1) {
1238   case JVM_CONSTANT_Class:
1239   {
1240     Klass* k1 = klass_at(index1, CHECK_false);
1241     Klass* k2 = cp2->klass_at(index2, CHECK_false);
1242     if (k1 == k2) {
1243       return true;
1244     }
1245   } break;
1246 
1247   case JVM_CONSTANT_ClassIndex:
1248   {
1249     int recur1 = klass_index_at(index1);
1250     int recur2 = cp2->klass_index_at(index2);
1251     bool match = compare_entry_to(recur1, cp2, recur2, CHECK_false);
1252     if (match) {
1253       return true;
1254     }
1255   } break;
1256 
1257   case JVM_CONSTANT_Double:
1258   {
1259     jdouble d1 = double_at(index1);
1260     jdouble d2 = cp2->double_at(index2);
1261     if (d1 == d2) {
1262       return true;
1263     }
1264   } break;
1265 
1266   case JVM_CONSTANT_Fieldref:
1267   case JVM_CONSTANT_InterfaceMethodref:
1268   case JVM_CONSTANT_Methodref:
1269   {
1270     int recur1 = uncached_klass_ref_index_at(index1);
1271     int recur2 = cp2->uncached_klass_ref_index_at(index2);
1272     bool match = compare_entry_to(recur1, cp2, recur2, CHECK_false);
1273     if (match) {
1274       recur1 = uncached_name_and_type_ref_index_at(index1);
1275       recur2 = cp2->uncached_name_and_type_ref_index_at(index2);
1276       match = compare_entry_to(recur1, cp2, recur2, CHECK_false);
1277       if (match) {
1278         return true;
1279       }
1280     }
1281   } break;
1282 
1283   case JVM_CONSTANT_Float:
1284   {
1285     jfloat f1 = float_at(index1);
1286     jfloat f2 = cp2->float_at(index2);
1287     if (f1 == f2) {
1288       return true;
1289     }
1290   } break;
1291 
1292   case JVM_CONSTANT_Integer:
1293   {
1294     jint i1 = int_at(index1);
1295     jint i2 = cp2->int_at(index2);
1296     if (i1 == i2) {
1297       return true;
1298     }
1299   } break;
1300 
1301   case JVM_CONSTANT_Long:
1302   {
1303     jlong l1 = long_at(index1);
1304     jlong l2 = cp2->long_at(index2);
1305     if (l1 == l2) {
1306       return true;
1307     }
1308   } break;
1309 
1310   case JVM_CONSTANT_NameAndType:
1311   {
1312     int recur1 = name_ref_index_at(index1);
1313     int recur2 = cp2->name_ref_index_at(index2);
1314     bool match = compare_entry_to(recur1, cp2, recur2, CHECK_false);
1315     if (match) {
1316       recur1 = signature_ref_index_at(index1);
1317       recur2 = cp2->signature_ref_index_at(index2);
1318       match = compare_entry_to(recur1, cp2, recur2, CHECK_false);
1319       if (match) {
1320         return true;
1321       }
1322     }
1323   } break;
1324 
1325   case JVM_CONSTANT_StringIndex:
1326   {
1327     int recur1 = string_index_at(index1);
1328     int recur2 = cp2->string_index_at(index2);
1329     bool match = compare_entry_to(recur1, cp2, recur2, CHECK_false);
1330     if (match) {
1331       return true;
1332     }
1333   } break;
1334 
1335   case JVM_CONSTANT_UnresolvedClass:
1336   {
1337     Symbol* k1 = klass_name_at(index1);
1338     Symbol* k2 = cp2->klass_name_at(index2);
1339     if (k1 == k2) {
1340       return true;
1341     }
1342   } break;
1343 
1344   case JVM_CONSTANT_MethodType:
1345   {
1346     int k1 = method_type_index_at(index1);
1347     int k2 = cp2->method_type_index_at(index2);
1348     bool match = compare_entry_to(k1, cp2, k2, CHECK_false);
1349     if (match) {
1350       return true;
1351     }
1352   } break;
1353 
1354   case JVM_CONSTANT_MethodHandle:
1355   {
1356     int k1 = method_handle_ref_kind_at(index1);
1357     int k2 = cp2->method_handle_ref_kind_at(index2);
1358     if (k1 == k2) {
1359       int i1 = method_handle_index_at(index1);
1360       int i2 = cp2->method_handle_index_at(index2);
1361       bool match = compare_entry_to(i1, cp2, i2, CHECK_false);
1362       if (match) {
1363         return true;
1364       }
1365     }
1366   } break;
1367 
1368   case JVM_CONSTANT_Dynamic:
1369   {
1370     int k1 = bootstrap_name_and_type_ref_index_at(index1);
1371     int k2 = cp2->bootstrap_name_and_type_ref_index_at(index2);
1372     int i1 = bootstrap_methods_attribute_index(index1);
1373     int i2 = cp2->bootstrap_methods_attribute_index(index2);
1374     // separate statements and variables because CHECK_false is used
1375     bool match_entry = compare_entry_to(k1, cp2, k2, CHECK_false);
1376     bool match_operand = compare_operand_to(i1, cp2, i2, CHECK_false);
1377     return (match_entry && match_operand);
1378   } break;
1379 
1380   case JVM_CONSTANT_InvokeDynamic:
1381   {
1382     int k1 = bootstrap_name_and_type_ref_index_at(index1);
1383     int k2 = cp2->bootstrap_name_and_type_ref_index_at(index2);
1384     int i1 = bootstrap_methods_attribute_index(index1);
1385     int i2 = cp2->bootstrap_methods_attribute_index(index2);
1386     // separate statements and variables because CHECK_false is used
1387     bool match_entry = compare_entry_to(k1, cp2, k2, CHECK_false);
1388     bool match_operand = compare_operand_to(i1, cp2, i2, CHECK_false);
1389     return (match_entry && match_operand);
1390   } break;
1391 
1392   case JVM_CONSTANT_String:
1393   {
1394     Symbol* s1 = unresolved_string_at(index1);
1395     Symbol* s2 = cp2->unresolved_string_at(index2);
1396     if (s1 == s2) {
1397       return true;
1398     }
1399   } break;
1400 
1401   case JVM_CONSTANT_Utf8:
1402   {
1403     Symbol* s1 = symbol_at(index1);
1404     Symbol* s2 = cp2->symbol_at(index2);
1405     if (s1 == s2) {
1406       return true;
1407     }
1408   } break;
1409 
1410   // Invalid is used as the tag for the second constant pool entry
1411   // occupied by JVM_CONSTANT_Double or JVM_CONSTANT_Long. It should
1412   // not be seen by itself.
1413   case JVM_CONSTANT_Invalid: // fall through
1414 
1415   default:
1416     ShouldNotReachHere();
1417     break;
1418   }
1419 
1420   return false;
1421 } // end compare_entry_to()
1422 
1423 
1424 // Resize the operands array with delta_len and delta_size.
1425 // Used in RedefineClasses for CP merge.
1426 void ConstantPool::resize_operands(int delta_len, int delta_size, TRAPS) {
1427   int old_len  = operand_array_length(operands());
1428   int new_len  = old_len + delta_len;
1429   int min_len  = (delta_len > 0) ? old_len : new_len;
1430 
1431   int old_size = operands()->length();
1432   int new_size = old_size + delta_size;
1433   int min_size = (delta_size > 0) ? old_size : new_size;
1434 
1435   ClassLoaderData* loader_data = pool_holder()->class_loader_data();
1436   Array<u2>* new_ops = MetadataFactory::new_array<u2>(loader_data, new_size, CHECK);
1437 
1438   // Set index in the resized array for existing elements only
1439   for (int idx = 0; idx < min_len; idx++) {
1440     int offset = operand_offset_at(idx);                       // offset in original array
1441     operand_offset_at_put(new_ops, idx, offset + 2*delta_len); // offset in resized array
1442   }
1443   // Copy the bootstrap specifiers only
1444   Copy::conjoint_memory_atomic(operands()->adr_at(2*old_len),
1445                                new_ops->adr_at(2*new_len),
1446                                (min_size - 2*min_len) * sizeof(u2));
1447   // Explicitly deallocate old operands array.
1448   // Note, it is not needed for 7u backport.
1449   if ( operands() != NULL) { // the safety check
1450     MetadataFactory::free_array<u2>(loader_data, operands());
1451   }
1452   set_operands(new_ops);
1453 } // end resize_operands()
1454 
1455 
1456 // Extend the operands array with the length and size of the ext_cp operands.
1457 // Used in RedefineClasses for CP merge.
1458 void ConstantPool::extend_operands(const constantPoolHandle& ext_cp, TRAPS) {
1459   int delta_len = operand_array_length(ext_cp->operands());
1460   if (delta_len == 0) {
1461     return; // nothing to do
1462   }
1463   int delta_size = ext_cp->operands()->length();
1464 
1465   assert(delta_len  > 0 && delta_size > 0, "extended operands array must be bigger");
1466 
1467   if (operand_array_length(operands()) == 0) {
1468     ClassLoaderData* loader_data = pool_holder()->class_loader_data();
1469     Array<u2>* new_ops = MetadataFactory::new_array<u2>(loader_data, delta_size, CHECK);
1470     // The first element index defines the offset of second part
1471     operand_offset_at_put(new_ops, 0, 2*delta_len); // offset in new array
1472     set_operands(new_ops);
1473   } else {
1474     resize_operands(delta_len, delta_size, CHECK);
1475   }
1476 
1477 } // end extend_operands()
1478 
1479 
1480 // Shrink the operands array to a smaller array with new_len length.
1481 // Used in RedefineClasses for CP merge.
1482 void ConstantPool::shrink_operands(int new_len, TRAPS) {
1483   int old_len = operand_array_length(operands());
1484   if (new_len == old_len) {
1485     return; // nothing to do
1486   }
1487   assert(new_len < old_len, "shrunken operands array must be smaller");
1488 
1489   int free_base  = operand_next_offset_at(new_len - 1);
1490   int delta_len  = new_len - old_len;
1491   int delta_size = 2*delta_len + free_base - operands()->length();
1492 
1493   resize_operands(delta_len, delta_size, CHECK);
1494 
1495 } // end shrink_operands()
1496 
1497 
1498 void ConstantPool::copy_operands(const constantPoolHandle& from_cp,
1499                                  const constantPoolHandle& to_cp,
1500                                  TRAPS) {
1501 
1502   int from_oplen = operand_array_length(from_cp->operands());
1503   int old_oplen  = operand_array_length(to_cp->operands());
1504   if (from_oplen != 0) {
1505     ClassLoaderData* loader_data = to_cp->pool_holder()->class_loader_data();
1506     // append my operands to the target's operands array
1507     if (old_oplen == 0) {
1508       // Can't just reuse from_cp's operand list because of deallocation issues
1509       int len = from_cp->operands()->length();
1510       Array<u2>* new_ops = MetadataFactory::new_array<u2>(loader_data, len, CHECK);
1511       Copy::conjoint_memory_atomic(
1512           from_cp->operands()->adr_at(0), new_ops->adr_at(0), len * sizeof(u2));
1513       to_cp->set_operands(new_ops);
1514     } else {
1515       int old_len  = to_cp->operands()->length();
1516       int from_len = from_cp->operands()->length();
1517       int old_off  = old_oplen * sizeof(u2);
1518       int from_off = from_oplen * sizeof(u2);
1519       // Use the metaspace for the destination constant pool
1520       Array<u2>* new_operands = MetadataFactory::new_array<u2>(loader_data, old_len + from_len, CHECK);
1521       int fillp = 0, len = 0;
1522       // first part of dest
1523       Copy::conjoint_memory_atomic(to_cp->operands()->adr_at(0),
1524                                    new_operands->adr_at(fillp),
1525                                    (len = old_off) * sizeof(u2));
1526       fillp += len;
1527       // first part of src
1528       Copy::conjoint_memory_atomic(from_cp->operands()->adr_at(0),
1529                                    new_operands->adr_at(fillp),
1530                                    (len = from_off) * sizeof(u2));
1531       fillp += len;
1532       // second part of dest
1533       Copy::conjoint_memory_atomic(to_cp->operands()->adr_at(old_off),
1534                                    new_operands->adr_at(fillp),
1535                                    (len = old_len - old_off) * sizeof(u2));
1536       fillp += len;
1537       // second part of src
1538       Copy::conjoint_memory_atomic(from_cp->operands()->adr_at(from_off),
1539                                    new_operands->adr_at(fillp),
1540                                    (len = from_len - from_off) * sizeof(u2));
1541       fillp += len;
1542       assert(fillp == new_operands->length(), "");
1543 
1544       // Adjust indexes in the first part of the copied operands array.
1545       for (int j = 0; j < from_oplen; j++) {
1546         int offset = operand_offset_at(new_operands, old_oplen + j);
1547         assert(offset == operand_offset_at(from_cp->operands(), j), "correct copy");
1548         offset += old_len;  // every new tuple is preceded by old_len extra u2's
1549         operand_offset_at_put(new_operands, old_oplen + j, offset);
1550       }
1551 
1552       // replace target operands array with combined array
1553       to_cp->set_operands(new_operands);
1554     }
1555   }
1556 } // end copy_operands()
1557 
1558 
1559 // Copy this constant pool's entries at start_i to end_i (inclusive)
1560 // to the constant pool to_cp's entries starting at to_i. A total of
1561 // (end_i - start_i) + 1 entries are copied.
1562 void ConstantPool::copy_cp_to_impl(const constantPoolHandle& from_cp, int start_i, int end_i,
1563        const constantPoolHandle& to_cp, int to_i, TRAPS) {
1564 
1565 
1566   int dest_i = to_i;  // leave original alone for debug purposes
1567 
1568   for (int src_i = start_i; src_i <= end_i; /* see loop bottom */ ) {
1569     copy_entry_to(from_cp, src_i, to_cp, dest_i, CHECK);
1570 
1571     switch (from_cp->tag_at(src_i).value()) {
1572     case JVM_CONSTANT_Double:
1573     case JVM_CONSTANT_Long:
1574       // double and long take two constant pool entries
1575       src_i += 2;
1576       dest_i += 2;
1577       break;
1578 
1579     default:
1580       // all others take one constant pool entry
1581       src_i++;
1582       dest_i++;
1583       break;
1584     }
1585   }
1586   copy_operands(from_cp, to_cp, CHECK);
1587 
1588 } // end copy_cp_to_impl()
1589 
1590 
1591 // Copy this constant pool's entry at from_i to the constant pool
1592 // to_cp's entry at to_i.
1593 void ConstantPool::copy_entry_to(const constantPoolHandle& from_cp, int from_i,
1594                                         const constantPoolHandle& to_cp, int to_i,
1595                                         TRAPS) {
1596 
1597   int tag = from_cp->tag_at(from_i).value();
1598   switch (tag) {
1599   case JVM_CONSTANT_ClassIndex:
1600   {
1601     jint ki = from_cp->klass_index_at(from_i);
1602     to_cp->klass_index_at_put(to_i, ki);
1603   } break;
1604 
1605   case JVM_CONSTANT_Double:
1606   {
1607     jdouble d = from_cp->double_at(from_i);
1608     to_cp->double_at_put(to_i, d);
1609     // double takes two constant pool entries so init second entry's tag
1610     to_cp->tag_at_put(to_i + 1, JVM_CONSTANT_Invalid);
1611   } break;
1612 
1613   case JVM_CONSTANT_Fieldref:
1614   {
1615     int class_index = from_cp->uncached_klass_ref_index_at(from_i);
1616     int name_and_type_index = from_cp->uncached_name_and_type_ref_index_at(from_i);
1617     to_cp->field_at_put(to_i, class_index, name_and_type_index);
1618   } break;
1619 
1620   case JVM_CONSTANT_Float:
1621   {
1622     jfloat f = from_cp->float_at(from_i);
1623     to_cp->float_at_put(to_i, f);
1624   } break;
1625 
1626   case JVM_CONSTANT_Integer:
1627   {
1628     jint i = from_cp->int_at(from_i);
1629     to_cp->int_at_put(to_i, i);
1630   } break;
1631 
1632   case JVM_CONSTANT_InterfaceMethodref:
1633   {
1634     int class_index = from_cp->uncached_klass_ref_index_at(from_i);
1635     int name_and_type_index = from_cp->uncached_name_and_type_ref_index_at(from_i);
1636     to_cp->interface_method_at_put(to_i, class_index, name_and_type_index);
1637   } break;
1638 
1639   case JVM_CONSTANT_Long:
1640   {
1641     jlong l = from_cp->long_at(from_i);
1642     to_cp->long_at_put(to_i, l);
1643     // long takes two constant pool entries so init second entry's tag
1644     to_cp->tag_at_put(to_i + 1, JVM_CONSTANT_Invalid);
1645   } break;
1646 
1647   case JVM_CONSTANT_Methodref:
1648   {
1649     int class_index = from_cp->uncached_klass_ref_index_at(from_i);
1650     int name_and_type_index = from_cp->uncached_name_and_type_ref_index_at(from_i);
1651     to_cp->method_at_put(to_i, class_index, name_and_type_index);
1652   } break;
1653 
1654   case JVM_CONSTANT_NameAndType:
1655   {
1656     int name_ref_index = from_cp->name_ref_index_at(from_i);
1657     int signature_ref_index = from_cp->signature_ref_index_at(from_i);
1658     to_cp->name_and_type_at_put(to_i, name_ref_index, signature_ref_index);
1659   } break;
1660 
1661   case JVM_CONSTANT_StringIndex:
1662   {
1663     jint si = from_cp->string_index_at(from_i);
1664     to_cp->string_index_at_put(to_i, si);
1665   } break;
1666 
1667   case JVM_CONSTANT_Class:
1668   case JVM_CONSTANT_UnresolvedClass:
1669   case JVM_CONSTANT_UnresolvedClassInError:
1670   {
1671     // Revert to JVM_CONSTANT_ClassIndex
1672     int name_index = from_cp->klass_slot_at(from_i).name_index();
1673     assert(from_cp->tag_at(name_index).is_symbol(), "sanity");
1674     to_cp->klass_index_at_put(to_i, name_index);
1675   } break;
1676 
1677   case JVM_CONSTANT_String:
1678   {
1679     Symbol* s = from_cp->unresolved_string_at(from_i);
1680     to_cp->unresolved_string_at_put(to_i, s);
1681   } break;
1682 
1683   case JVM_CONSTANT_Utf8:
1684   {
1685     Symbol* s = from_cp->symbol_at(from_i);
1686     // Need to increase refcount, the old one will be thrown away and deferenced
1687     s->increment_refcount();
1688     to_cp->symbol_at_put(to_i, s);
1689   } break;
1690 
1691   case JVM_CONSTANT_MethodType:
1692   case JVM_CONSTANT_MethodTypeInError:
1693   {
1694     jint k = from_cp->method_type_index_at(from_i);
1695     to_cp->method_type_index_at_put(to_i, k);
1696   } break;
1697 
1698   case JVM_CONSTANT_MethodHandle:
1699   case JVM_CONSTANT_MethodHandleInError:
1700   {
1701     int k1 = from_cp->method_handle_ref_kind_at(from_i);
1702     int k2 = from_cp->method_handle_index_at(from_i);
1703     to_cp->method_handle_index_at_put(to_i, k1, k2);
1704   } break;
1705 
1706   case JVM_CONSTANT_Dynamic:
1707   case JVM_CONSTANT_DynamicInError:
1708   {
1709     int k1 = from_cp->bootstrap_methods_attribute_index(from_i);
1710     int k2 = from_cp->bootstrap_name_and_type_ref_index_at(from_i);
1711     k1 += operand_array_length(to_cp->operands());  // to_cp might already have operands
1712     to_cp->dynamic_constant_at_put(to_i, k1, k2);
1713   } break;
1714 
1715   case JVM_CONSTANT_InvokeDynamic:
1716   {
1717     int k1 = from_cp->bootstrap_methods_attribute_index(from_i);
1718     int k2 = from_cp->bootstrap_name_and_type_ref_index_at(from_i);
1719     k1 += operand_array_length(to_cp->operands());  // to_cp might already have operands
1720     to_cp->invoke_dynamic_at_put(to_i, k1, k2);
1721   } break;
1722 
1723   // Invalid is used as the tag for the second constant pool entry
1724   // occupied by JVM_CONSTANT_Double or JVM_CONSTANT_Long. It should
1725   // not be seen by itself.
1726   case JVM_CONSTANT_Invalid: // fall through
1727 
1728   default:
1729   {
1730     ShouldNotReachHere();
1731   } break;
1732   }
1733 } // end copy_entry_to()
1734 
1735 // Search constant pool search_cp for an entry that matches this
1736 // constant pool's entry at pattern_i. Returns the index of a
1737 // matching entry or zero (0) if there is no matching entry.
1738 int ConstantPool::find_matching_entry(int pattern_i,
1739       const constantPoolHandle& search_cp, TRAPS) {
1740 
1741   // index zero (0) is not used
1742   for (int i = 1; i < search_cp->length(); i++) {
1743     bool found = compare_entry_to(pattern_i, search_cp, i, CHECK_0);
1744     if (found) {
1745       return i;
1746     }
1747   }
1748 
1749   return 0;  // entry not found; return unused index zero (0)
1750 } // end find_matching_entry()
1751 
1752 
1753 // Compare this constant pool's bootstrap specifier at idx1 to the constant pool
1754 // cp2's bootstrap specifier at idx2.
1755 bool ConstantPool::compare_operand_to(int idx1, const constantPoolHandle& cp2, int idx2, TRAPS) {
1756   int k1 = operand_bootstrap_method_ref_index_at(idx1);
1757   int k2 = cp2->operand_bootstrap_method_ref_index_at(idx2);
1758   bool match = compare_entry_to(k1, cp2, k2, CHECK_false);
1759 
1760   if (!match) {
1761     return false;
1762   }
1763   int argc = operand_argument_count_at(idx1);
1764   if (argc == cp2->operand_argument_count_at(idx2)) {
1765     for (int j = 0; j < argc; j++) {
1766       k1 = operand_argument_index_at(idx1, j);
1767       k2 = cp2->operand_argument_index_at(idx2, j);
1768       match = compare_entry_to(k1, cp2, k2, CHECK_false);
1769       if (!match) {
1770         return false;
1771       }
1772     }
1773     return true;           // got through loop; all elements equal
1774   }
1775   return false;
1776 } // end compare_operand_to()
1777 
1778 // Search constant pool search_cp for a bootstrap specifier that matches
1779 // this constant pool's bootstrap specifier data at pattern_i index.
1780 // Return the index of a matching bootstrap attribute record or (-1) if there is no match.
1781 int ConstantPool::find_matching_operand(int pattern_i,
1782                     const constantPoolHandle& search_cp, int search_len, TRAPS) {
1783   for (int i = 0; i < search_len; i++) {
1784     bool found = compare_operand_to(pattern_i, search_cp, i, CHECK_(-1));
1785     if (found) {
1786       return i;
1787     }
1788   }
1789   return -1;  // bootstrap specifier data not found; return unused index (-1)
1790 } // end find_matching_operand()
1791 
1792 
1793 #ifndef PRODUCT
1794 
1795 const char* ConstantPool::printable_name_at(int which) {
1796 
1797   constantTag tag = tag_at(which);
1798 
1799   if (tag.is_string()) {
1800     return string_at_noresolve(which);
1801   } else if (tag.is_klass() || tag.is_unresolved_klass()) {
1802     return klass_name_at(which)->as_C_string();
1803   } else if (tag.is_symbol()) {
1804     return symbol_at(which)->as_C_string();
1805   }
1806   return "";
1807 }
1808 
1809 #endif // PRODUCT
1810 
1811 
1812 // JVMTI GetConstantPool support
1813 
1814 // For debugging of constant pool
1815 const bool debug_cpool = false;
1816 
1817 #define DBG(code) do { if (debug_cpool) { (code); } } while(0)
1818 
1819 static void print_cpool_bytes(jint cnt, u1 *bytes) {
1820   const char* WARN_MSG = "Must not be such entry!";
1821   jint size = 0;
1822   u2   idx1, idx2;
1823 
1824   for (jint idx = 1; idx < cnt; idx++) {
1825     jint ent_size = 0;
1826     u1   tag  = *bytes++;
1827     size++;                       // count tag
1828 
1829     printf("const #%03d, tag: %02d ", idx, tag);
1830     switch(tag) {
1831       case JVM_CONSTANT_Invalid: {
1832         printf("Invalid");
1833         break;
1834       }
1835       case JVM_CONSTANT_Unicode: {
1836         printf("Unicode      %s", WARN_MSG);
1837         break;
1838       }
1839       case JVM_CONSTANT_Utf8: {
1840         u2 len = Bytes::get_Java_u2(bytes);
1841         char str[128];
1842         if (len > 127) {
1843            len = 127;
1844         }
1845         strncpy(str, (char *) (bytes+2), len);
1846         str[len] = '\0';
1847         printf("Utf8          \"%s\"", str);
1848         ent_size = 2 + len;
1849         break;
1850       }
1851       case JVM_CONSTANT_Integer: {
1852         u4 val = Bytes::get_Java_u4(bytes);
1853         printf("int          %d", *(int *) &val);
1854         ent_size = 4;
1855         break;
1856       }
1857       case JVM_CONSTANT_Float: {
1858         u4 val = Bytes::get_Java_u4(bytes);
1859         printf("float        %5.3ff", *(float *) &val);
1860         ent_size = 4;
1861         break;
1862       }
1863       case JVM_CONSTANT_Long: {
1864         u8 val = Bytes::get_Java_u8(bytes);
1865         printf("long         " INT64_FORMAT, (int64_t) *(jlong *) &val);
1866         ent_size = 8;
1867         idx++; // Long takes two cpool slots
1868         break;
1869       }
1870       case JVM_CONSTANT_Double: {
1871         u8 val = Bytes::get_Java_u8(bytes);
1872         printf("double       %5.3fd", *(jdouble *)&val);
1873         ent_size = 8;
1874         idx++; // Double takes two cpool slots
1875         break;
1876       }
1877       case JVM_CONSTANT_Class: {
1878         idx1 = Bytes::get_Java_u2(bytes);
1879         printf("class        #%03d", idx1);
1880         ent_size = 2;
1881         break;
1882       }
1883       case JVM_CONSTANT_String: {
1884         idx1 = Bytes::get_Java_u2(bytes);
1885         printf("String       #%03d", idx1);
1886         ent_size = 2;
1887         break;
1888       }
1889       case JVM_CONSTANT_Fieldref: {
1890         idx1 = Bytes::get_Java_u2(bytes);
1891         idx2 = Bytes::get_Java_u2(bytes+2);
1892         printf("Field        #%03d, #%03d", (int) idx1, (int) idx2);
1893         ent_size = 4;
1894         break;
1895       }
1896       case JVM_CONSTANT_Methodref: {
1897         idx1 = Bytes::get_Java_u2(bytes);
1898         idx2 = Bytes::get_Java_u2(bytes+2);
1899         printf("Method       #%03d, #%03d", idx1, idx2);
1900         ent_size = 4;
1901         break;
1902       }
1903       case JVM_CONSTANT_InterfaceMethodref: {
1904         idx1 = Bytes::get_Java_u2(bytes);
1905         idx2 = Bytes::get_Java_u2(bytes+2);
1906         printf("InterfMethod #%03d, #%03d", idx1, idx2);
1907         ent_size = 4;
1908         break;
1909       }
1910       case JVM_CONSTANT_NameAndType: {
1911         idx1 = Bytes::get_Java_u2(bytes);
1912         idx2 = Bytes::get_Java_u2(bytes+2);
1913         printf("NameAndType  #%03d, #%03d", idx1, idx2);
1914         ent_size = 4;
1915         break;
1916       }
1917       case JVM_CONSTANT_ClassIndex: {
1918         printf("ClassIndex  %s", WARN_MSG);
1919         break;
1920       }
1921       case JVM_CONSTANT_UnresolvedClass: {
1922         printf("UnresolvedClass: %s", WARN_MSG);
1923         break;
1924       }
1925       case JVM_CONSTANT_UnresolvedClassInError: {
1926         printf("UnresolvedClassInErr: %s", WARN_MSG);
1927         break;
1928       }
1929       case JVM_CONSTANT_StringIndex: {
1930         printf("StringIndex: %s", WARN_MSG);
1931         break;
1932       }
1933     }
1934     printf(";\n");
1935     bytes += ent_size;
1936     size  += ent_size;
1937   }
1938   printf("Cpool size: %d\n", size);
1939   fflush(0);
1940   return;
1941 } /* end print_cpool_bytes */
1942 
1943 
1944 // Returns size of constant pool entry.
1945 jint ConstantPool::cpool_entry_size(jint idx) {
1946   switch(tag_at(idx).value()) {
1947     case JVM_CONSTANT_Invalid:
1948     case JVM_CONSTANT_Unicode:
1949       return 1;
1950 
1951     case JVM_CONSTANT_Utf8:
1952       return 3 + symbol_at(idx)->utf8_length();
1953 
1954     case JVM_CONSTANT_Class:
1955     case JVM_CONSTANT_String:
1956     case JVM_CONSTANT_ClassIndex:
1957     case JVM_CONSTANT_UnresolvedClass:
1958     case JVM_CONSTANT_UnresolvedClassInError:
1959     case JVM_CONSTANT_StringIndex:
1960     case JVM_CONSTANT_MethodType:
1961     case JVM_CONSTANT_MethodTypeInError:
1962       return 3;
1963 
1964     case JVM_CONSTANT_MethodHandle:
1965     case JVM_CONSTANT_MethodHandleInError:
1966       return 4; //tag, ref_kind, ref_index
1967 
1968     case JVM_CONSTANT_Integer:
1969     case JVM_CONSTANT_Float:
1970     case JVM_CONSTANT_Fieldref:
1971     case JVM_CONSTANT_Methodref:
1972     case JVM_CONSTANT_InterfaceMethodref:
1973     case JVM_CONSTANT_NameAndType:
1974       return 5;
1975 
1976     case JVM_CONSTANT_Dynamic:
1977     case JVM_CONSTANT_DynamicInError:
1978     case JVM_CONSTANT_InvokeDynamic:
1979       // u1 tag, u2 bsm, u2 nt
1980       return 5;
1981 
1982     case JVM_CONSTANT_Long:
1983     case JVM_CONSTANT_Double:
1984       return 9;
1985   }
1986   assert(false, "cpool_entry_size: Invalid constant pool entry tag");
1987   return 1;
1988 } /* end cpool_entry_size */
1989 
1990 
1991 // SymbolHashMap is used to find a constant pool index from a string.
1992 // This function fills in SymbolHashMaps, one for utf8s and one for
1993 // class names, returns size of the cpool raw bytes.
1994 jint ConstantPool::hash_entries_to(SymbolHashMap *symmap,
1995                                           SymbolHashMap *classmap) {
1996   jint size = 0;
1997 
1998   for (u2 idx = 1; idx < length(); idx++) {
1999     u2 tag = tag_at(idx).value();
2000     size += cpool_entry_size(idx);
2001 
2002     switch(tag) {
2003       case JVM_CONSTANT_Utf8: {
2004         Symbol* sym = symbol_at(idx);
2005         symmap->add_entry(sym, idx);
2006         DBG(printf("adding symbol entry %s = %d\n", sym->as_utf8(), idx));
2007         break;
2008       }
2009       case JVM_CONSTANT_Class:
2010       case JVM_CONSTANT_UnresolvedClass:
2011       case JVM_CONSTANT_UnresolvedClassInError: {
2012         Symbol* sym = klass_name_at(idx);
2013         classmap->add_entry(sym, idx);
2014         DBG(printf("adding class entry %s = %d\n", sym->as_utf8(), idx));
2015         break;
2016       }
2017       case JVM_CONSTANT_Long:
2018       case JVM_CONSTANT_Double: {
2019         idx++; // Both Long and Double take two cpool slots
2020         break;
2021       }
2022     }
2023   }
2024   return size;
2025 } /* end hash_utf8_entries_to */
2026 
2027 
2028 // Copy cpool bytes.
2029 // Returns:
2030 //    0, in case of OutOfMemoryError
2031 //   -1, in case of internal error
2032 //  > 0, count of the raw cpool bytes that have been copied
2033 int ConstantPool::copy_cpool_bytes(int cpool_size,
2034                                           SymbolHashMap* tbl,
2035                                           unsigned char *bytes) {
2036   u2   idx1, idx2;
2037   jint size  = 0;
2038   jint cnt   = length();
2039   unsigned char *start_bytes = bytes;
2040 
2041   for (jint idx = 1; idx < cnt; idx++) {
2042     u1   tag      = tag_at(idx).value();
2043     jint ent_size = cpool_entry_size(idx);
2044 
2045     assert(size + ent_size <= cpool_size, "Size mismatch");
2046 
2047     *bytes = tag;
2048     DBG(printf("#%03hd tag=%03hd, ", (short)idx, (short)tag));
2049     switch(tag) {
2050       case JVM_CONSTANT_Invalid: {
2051         DBG(printf("JVM_CONSTANT_Invalid"));
2052         break;
2053       }
2054       case JVM_CONSTANT_Unicode: {
2055         assert(false, "Wrong constant pool tag: JVM_CONSTANT_Unicode");
2056         DBG(printf("JVM_CONSTANT_Unicode"));
2057         break;
2058       }
2059       case JVM_CONSTANT_Utf8: {
2060         Symbol* sym = symbol_at(idx);
2061         char*     str = sym->as_utf8();
2062         // Warning! It's crashing on x86 with len = sym->utf8_length()
2063         int       len = (int) strlen(str);
2064         Bytes::put_Java_u2((address) (bytes+1), (u2) len);
2065         for (int i = 0; i < len; i++) {
2066             bytes[3+i] = (u1) str[i];
2067         }
2068         DBG(printf("JVM_CONSTANT_Utf8: %s ", str));
2069         break;
2070       }
2071       case JVM_CONSTANT_Integer: {
2072         jint val = int_at(idx);
2073         Bytes::put_Java_u4((address) (bytes+1), *(u4*)&val);
2074         break;
2075       }
2076       case JVM_CONSTANT_Float: {
2077         jfloat val = float_at(idx);
2078         Bytes::put_Java_u4((address) (bytes+1), *(u4*)&val);
2079         break;
2080       }
2081       case JVM_CONSTANT_Long: {
2082         jlong val = long_at(idx);
2083         Bytes::put_Java_u8((address) (bytes+1), *(u8*)&val);
2084         idx++;             // Long takes two cpool slots
2085         break;
2086       }
2087       case JVM_CONSTANT_Double: {
2088         jdouble val = double_at(idx);
2089         Bytes::put_Java_u8((address) (bytes+1), *(u8*)&val);
2090         idx++;             // Double takes two cpool slots
2091         break;
2092       }
2093       case JVM_CONSTANT_Class:
2094       case JVM_CONSTANT_UnresolvedClass:
2095       case JVM_CONSTANT_UnresolvedClassInError: {
2096         *bytes = JVM_CONSTANT_Class;
2097         Symbol* sym = klass_name_at(idx);
2098         idx1 = tbl->symbol_to_value(sym);
2099         assert(idx1 != 0, "Have not found a hashtable entry");
2100         Bytes::put_Java_u2((address) (bytes+1), idx1);
2101         DBG(printf("JVM_CONSTANT_Class: idx=#%03hd, %s", idx1, sym->as_utf8()));
2102         break;
2103       }
2104       case JVM_CONSTANT_String: {
2105         *bytes = JVM_CONSTANT_String;
2106         Symbol* sym = unresolved_string_at(idx);
2107         idx1 = tbl->symbol_to_value(sym);
2108         assert(idx1 != 0, "Have not found a hashtable entry");
2109         Bytes::put_Java_u2((address) (bytes+1), idx1);
2110         DBG(printf("JVM_CONSTANT_String: idx=#%03hd, %s", idx1, sym->as_utf8()));
2111         break;
2112       }
2113       case JVM_CONSTANT_Fieldref:
2114       case JVM_CONSTANT_Methodref:
2115       case JVM_CONSTANT_InterfaceMethodref: {
2116         idx1 = uncached_klass_ref_index_at(idx);
2117         idx2 = uncached_name_and_type_ref_index_at(idx);
2118         Bytes::put_Java_u2((address) (bytes+1), idx1);
2119         Bytes::put_Java_u2((address) (bytes+3), idx2);
2120         DBG(printf("JVM_CONSTANT_Methodref: %hd %hd", idx1, idx2));
2121         break;
2122       }
2123       case JVM_CONSTANT_NameAndType: {
2124         idx1 = name_ref_index_at(idx);
2125         idx2 = signature_ref_index_at(idx);
2126         Bytes::put_Java_u2((address) (bytes+1), idx1);
2127         Bytes::put_Java_u2((address) (bytes+3), idx2);
2128         DBG(printf("JVM_CONSTANT_NameAndType: %hd %hd", idx1, idx2));
2129         break;
2130       }
2131       case JVM_CONSTANT_ClassIndex: {
2132         *bytes = JVM_CONSTANT_Class;
2133         idx1 = klass_index_at(idx);
2134         Bytes::put_Java_u2((address) (bytes+1), idx1);
2135         DBG(printf("JVM_CONSTANT_ClassIndex: %hd", idx1));
2136         break;
2137       }
2138       case JVM_CONSTANT_StringIndex: {
2139         *bytes = JVM_CONSTANT_String;
2140         idx1 = string_index_at(idx);
2141         Bytes::put_Java_u2((address) (bytes+1), idx1);
2142         DBG(printf("JVM_CONSTANT_StringIndex: %hd", idx1));
2143         break;
2144       }
2145       case JVM_CONSTANT_MethodHandle:
2146       case JVM_CONSTANT_MethodHandleInError: {
2147         *bytes = JVM_CONSTANT_MethodHandle;
2148         int kind = method_handle_ref_kind_at(idx);
2149         idx1 = method_handle_index_at(idx);
2150         *(bytes+1) = (unsigned char) kind;
2151         Bytes::put_Java_u2((address) (bytes+2), idx1);
2152         DBG(printf("JVM_CONSTANT_MethodHandle: %d %hd", kind, idx1));
2153         break;
2154       }
2155       case JVM_CONSTANT_MethodType:
2156       case JVM_CONSTANT_MethodTypeInError: {
2157         *bytes = JVM_CONSTANT_MethodType;
2158         idx1 = method_type_index_at(idx);
2159         Bytes::put_Java_u2((address) (bytes+1), idx1);
2160         DBG(printf("JVM_CONSTANT_MethodType: %hd", idx1));
2161         break;
2162       }
2163       case JVM_CONSTANT_Dynamic:
2164       case JVM_CONSTANT_DynamicInError: {
2165         *bytes = tag;
2166         idx1 = extract_low_short_from_int(*int_at_addr(idx));
2167         idx2 = extract_high_short_from_int(*int_at_addr(idx));
2168         assert(idx2 == bootstrap_name_and_type_ref_index_at(idx), "correct half of u4");
2169         Bytes::put_Java_u2((address) (bytes+1), idx1);
2170         Bytes::put_Java_u2((address) (bytes+3), idx2);
2171         DBG(printf("JVM_CONSTANT_Dynamic: %hd %hd", idx1, idx2));
2172         break;
2173       }
2174       case JVM_CONSTANT_InvokeDynamic: {
2175         *bytes = tag;
2176         idx1 = extract_low_short_from_int(*int_at_addr(idx));
2177         idx2 = extract_high_short_from_int(*int_at_addr(idx));
2178         assert(idx2 == bootstrap_name_and_type_ref_index_at(idx), "correct half of u4");
2179         Bytes::put_Java_u2((address) (bytes+1), idx1);
2180         Bytes::put_Java_u2((address) (bytes+3), idx2);
2181         DBG(printf("JVM_CONSTANT_InvokeDynamic: %hd %hd", idx1, idx2));
2182         break;
2183       }
2184     }
2185     DBG(printf("\n"));
2186     bytes += ent_size;
2187     size  += ent_size;
2188   }
2189   assert(size == cpool_size, "Size mismatch");
2190 
2191   // Keep temorarily for debugging until it's stable.
2192   DBG(print_cpool_bytes(cnt, start_bytes));
2193   return (int)(bytes - start_bytes);
2194 } /* end copy_cpool_bytes */
2195 
2196 #undef DBG
2197 
2198 
2199 void ConstantPool::set_on_stack(const bool value) {
2200   if (value) {
2201     // Only record if it's not already set.
2202     if (!on_stack()) {
2203       assert(!is_shared(), "should always be set for shared constant pools");
2204       _flags |= _on_stack;
2205       MetadataOnStackMark::record(this);
2206     }
2207   } else {
2208     // Clearing is done single-threadedly.
2209     if (!is_shared()) {
2210       _flags &= ~_on_stack;
2211     }
2212   }
2213 }
2214 
2215 // JSR 292 support for patching constant pool oops after the class is linked and
2216 // the oop array for resolved references are created.
2217 // We can't do this during classfile parsing, which is how the other indexes are
2218 // patched.  The other patches are applied early for some error checking
2219 // so only defer the pseudo_strings.
2220 void ConstantPool::patch_resolved_references(GrowableArray<Handle>* cp_patches) {
2221   for (int index = 1; index < cp_patches->length(); index++) { // Index 0 is unused
2222     Handle patch = cp_patches->at(index);
2223     if (patch.not_null()) {
2224       assert (tag_at(index).is_string(), "should only be string left");
2225       // Patching a string means pre-resolving it.
2226       // The spelling in the constant pool is ignored.
2227       // The constant reference may be any object whatever.
2228       // If it is not a real interned string, the constant is referred
2229       // to as a "pseudo-string", and must be presented to the CP
2230       // explicitly, because it may require scavenging.
2231       int obj_index = cp_to_object_index(index);
2232       pseudo_string_at_put(index, obj_index, patch());
2233      DEBUG_ONLY(cp_patches->at_put(index, Handle());)
2234     }
2235   }
2236 #ifdef ASSERT
2237   // Ensure that all the patches have been used.
2238   for (int index = 0; index < cp_patches->length(); index++) {
2239     assert(cp_patches->at(index).is_null(),
2240            "Unused constant pool patch at %d in class file %s",
2241            index,
2242            pool_holder()->external_name());
2243   }
2244 #endif // ASSERT
2245 }
2246 
2247 // Printing
2248 
2249 void ConstantPool::print_on(outputStream* st) const {
2250   assert(is_constantPool(), "must be constantPool");
2251   st->print_cr("%s", internal_name());
2252   if (flags() != 0) {
2253     st->print(" - flags: 0x%x", flags());
2254     if (has_preresolution()) st->print(" has_preresolution");
2255     if (on_stack()) st->print(" on_stack");
2256     st->cr();
2257   }
2258   if (pool_holder() != NULL) {
2259     st->print_cr(" - holder: " INTPTR_FORMAT, p2i(pool_holder()));
2260   }
2261   st->print_cr(" - cache: " INTPTR_FORMAT, p2i(cache()));
2262   st->print_cr(" - resolved_references: " INTPTR_FORMAT, p2i(resolved_references()));
2263   st->print_cr(" - reference_map: " INTPTR_FORMAT, p2i(reference_map()));
2264   st->print_cr(" - resolved_klasses: " INTPTR_FORMAT, p2i(resolved_klasses()));
2265 
2266   for (int index = 1; index < length(); index++) {      // Index 0 is unused
2267     ((ConstantPool*)this)->print_entry_on(index, st);
2268     switch (tag_at(index).value()) {
2269       case JVM_CONSTANT_Long :
2270       case JVM_CONSTANT_Double :
2271         index++;   // Skip entry following eigth-byte constant
2272     }
2273 
2274   }
2275   st->cr();
2276 }
2277 
2278 // Print one constant pool entry
2279 void ConstantPool::print_entry_on(const int index, outputStream* st) {
2280   EXCEPTION_MARK;
2281   st->print(" - %3d : ", index);
2282   tag_at(index).print_on(st);
2283   st->print(" : ");
2284   switch (tag_at(index).value()) {
2285     case JVM_CONSTANT_Class :
2286       { Klass* k = klass_at(index, CATCH);
2287         guarantee(k != NULL, "need klass");
2288         k->print_value_on(st);
2289         st->print(" {" PTR_FORMAT "}", p2i(k));
2290       }
2291       break;
2292     case JVM_CONSTANT_Fieldref :
2293     case JVM_CONSTANT_Methodref :
2294     case JVM_CONSTANT_InterfaceMethodref :
2295       st->print("klass_index=%d", uncached_klass_ref_index_at(index));
2296       st->print(" name_and_type_index=%d", uncached_name_and_type_ref_index_at(index));
2297       break;
2298     case JVM_CONSTANT_String :
2299       if (is_pseudo_string_at(index)) {
2300         oop anObj = pseudo_string_at(index);
2301         anObj->print_value_on(st);
2302         st->print(" {" PTR_FORMAT "}", p2i(anObj));
2303       } else {
2304         unresolved_string_at(index)->print_value_on(st);
2305       }
2306       break;
2307     case JVM_CONSTANT_Integer :
2308       st->print("%d", int_at(index));
2309       break;
2310     case JVM_CONSTANT_Float :
2311       st->print("%f", float_at(index));
2312       break;
2313     case JVM_CONSTANT_Long :
2314       st->print_jlong(long_at(index));
2315       break;
2316     case JVM_CONSTANT_Double :
2317       st->print("%lf", double_at(index));
2318       break;
2319     case JVM_CONSTANT_NameAndType :
2320       st->print("name_index=%d", name_ref_index_at(index));
2321       st->print(" signature_index=%d", signature_ref_index_at(index));
2322       break;
2323     case JVM_CONSTANT_Utf8 :
2324       symbol_at(index)->print_value_on(st);
2325       break;
2326     case JVM_CONSTANT_ClassIndex: {
2327         int name_index = *int_at_addr(index);
2328         st->print("klass_index=%d ", name_index);
2329         symbol_at(name_index)->print_value_on(st);
2330       }
2331       break;
2332     case JVM_CONSTANT_UnresolvedClass :               // fall-through
2333     case JVM_CONSTANT_UnresolvedClassInError: {
2334         CPKlassSlot kslot = klass_slot_at(index);
2335         int resolved_klass_index = kslot.resolved_klass_index();
2336         int name_index = kslot.name_index();
2337         assert(tag_at(name_index).is_symbol(), "sanity");
2338 
2339         Klass* klass = resolved_klasses()->at(resolved_klass_index);
2340         if (klass != NULL) {
2341           klass->print_value_on(st);
2342         } else {
2343           symbol_at(name_index)->print_value_on(st);
2344         }
2345       }
2346       break;
2347     case JVM_CONSTANT_MethodHandle :
2348     case JVM_CONSTANT_MethodHandleInError :
2349       st->print("ref_kind=%d", method_handle_ref_kind_at(index));
2350       st->print(" ref_index=%d", method_handle_index_at(index));
2351       break;
2352     case JVM_CONSTANT_MethodType :
2353     case JVM_CONSTANT_MethodTypeInError :
2354       st->print("signature_index=%d", method_type_index_at(index));
2355       break;
2356     case JVM_CONSTANT_Dynamic :
2357     case JVM_CONSTANT_DynamicInError :
2358       {
2359         st->print("bootstrap_method_index=%d", bootstrap_method_ref_index_at(index));
2360         st->print(" type_index=%d", bootstrap_name_and_type_ref_index_at(index));
2361         int argc = bootstrap_argument_count_at(index);
2362         if (argc > 0) {
2363           for (int arg_i = 0; arg_i < argc; arg_i++) {
2364             int arg = bootstrap_argument_index_at(index, arg_i);
2365             st->print((arg_i == 0 ? " arguments={%d" : ", %d"), arg);
2366           }
2367           st->print("}");
2368         }
2369       }
2370       break;
2371     case JVM_CONSTANT_InvokeDynamic :
2372       {
2373         st->print("bootstrap_method_index=%d", bootstrap_method_ref_index_at(index));
2374         st->print(" name_and_type_index=%d", bootstrap_name_and_type_ref_index_at(index));
2375         int argc = bootstrap_argument_count_at(index);
2376         if (argc > 0) {
2377           for (int arg_i = 0; arg_i < argc; arg_i++) {
2378             int arg = bootstrap_argument_index_at(index, arg_i);
2379             st->print((arg_i == 0 ? " arguments={%d" : ", %d"), arg);
2380           }
2381           st->print("}");
2382         }
2383       }
2384       break;
2385     default:
2386       ShouldNotReachHere();
2387       break;
2388   }
2389   st->cr();
2390 }
2391 
2392 void ConstantPool::print_value_on(outputStream* st) const {
2393   assert(is_constantPool(), "must be constantPool");
2394   st->print("constant pool [%d]", length());
2395   if (has_preresolution()) st->print("/preresolution");
2396   if (operands() != NULL)  st->print("/operands[%d]", operands()->length());
2397   print_address_on(st);
2398   if (pool_holder() != NULL) {
2399     st->print(" for ");
2400     pool_holder()->print_value_on(st);
2401     bool extra = (pool_holder()->constants() != this);
2402     if (extra)  st->print(" (extra)");
2403   }
2404   if (cache() != NULL) {
2405     st->print(" cache=" PTR_FORMAT, p2i(cache()));
2406   }
2407 }
2408 
2409 // Verification
2410 
2411 void ConstantPool::verify_on(outputStream* st) {
2412   guarantee(is_constantPool(), "object must be constant pool");
2413   for (int i = 0; i< length();  i++) {
2414     constantTag tag = tag_at(i);
2415     if (tag.is_klass() || tag.is_unresolved_klass()) {
2416       guarantee(klass_name_at(i)->refcount() != 0, "should have nonzero reference count");
2417     } else if (tag.is_symbol()) {
2418       CPSlot entry = slot_at(i);
2419       guarantee(entry.get_symbol()->refcount() != 0, "should have nonzero reference count");
2420     } else if (tag.is_string()) {
2421       CPSlot entry = slot_at(i);
2422       guarantee(entry.get_symbol()->refcount() != 0, "should have nonzero reference count");
2423     }
2424   }
2425   if (pool_holder() != NULL) {
2426     // Note: pool_holder() can be NULL in temporary constant pools
2427     // used during constant pool merging
2428     guarantee(pool_holder()->is_klass(),    "should be klass");
2429   }
2430 }
2431 
2432 
2433 SymbolHashMap::~SymbolHashMap() {
2434   SymbolHashMapEntry* next;
2435   for (int i = 0; i < _table_size; i++) {
2436     for (SymbolHashMapEntry* cur = bucket(i); cur != NULL; cur = next) {
2437       next = cur->next();
2438       delete(cur);
2439     }
2440   }
2441   FREE_C_HEAP_ARRAY(SymbolHashMapBucket, _buckets);
2442 }
2443 
2444 void SymbolHashMap::add_entry(Symbol* sym, u2 value) {
2445   char *str = sym->as_utf8();
2446   unsigned int hash = compute_hash(str, sym->utf8_length());
2447   unsigned int index = hash % table_size();
2448 
2449   // check if already in map
2450   // we prefer the first entry since it is more likely to be what was used in
2451   // the class file
2452   for (SymbolHashMapEntry *en = bucket(index); en != NULL; en = en->next()) {
2453     assert(en->symbol() != NULL, "SymbolHashMapEntry symbol is NULL");
2454     if (en->hash() == hash && en->symbol() == sym) {
2455         return;  // already there
2456     }
2457   }
2458 
2459   SymbolHashMapEntry* entry = new SymbolHashMapEntry(hash, sym, value);
2460   entry->set_next(bucket(index));
2461   _buckets[index].set_entry(entry);
2462   assert(entry->symbol() != NULL, "SymbolHashMapEntry symbol is NULL");
2463 }
2464 
2465 SymbolHashMapEntry* SymbolHashMap::find_entry(Symbol* sym) {
2466   assert(sym != NULL, "SymbolHashMap::find_entry - symbol is NULL");
2467   char *str = sym->as_utf8();
2468   int   len = sym->utf8_length();
2469   unsigned int hash = SymbolHashMap::compute_hash(str, len);
2470   unsigned int index = hash % table_size();
2471   for (SymbolHashMapEntry *en = bucket(index); en != NULL; en = en->next()) {
2472     assert(en->symbol() != NULL, "SymbolHashMapEntry symbol is NULL");
2473     if (en->hash() == hash && en->symbol() == sym) {
2474       return en;
2475     }
2476   }
2477   return NULL;
2478 }
2479 
2480 void SymbolHashMap::initialize_table(int table_size) {
2481   _table_size = table_size;
2482   _buckets = NEW_C_HEAP_ARRAY(SymbolHashMapBucket, table_size, mtSymbol);
2483   for (int index = 0; index < table_size; index++) {
2484     _buckets[index].clear();
2485   }
2486 }