1 /*
   2  * Copyright (c) 1997, 2018, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "jvm.h"
  27 #include "classfile/classLoaderData.hpp"
  28 #include "classfile/javaClasses.inline.hpp"
  29 #include "classfile/metadataOnStackMark.hpp"
  30 #include "classfile/stringTable.hpp"
  31 #include "classfile/systemDictionary.hpp"
  32 #include "classfile/vmSymbols.hpp"
  33 #include "interpreter/linkResolver.hpp"
  34 #include "memory/allocation.inline.hpp"
  35 #include "memory/heapInspection.hpp"
  36 #include "memory/metadataFactory.hpp"
  37 #include "memory/metaspaceClosure.hpp"
  38 #include "memory/metaspaceShared.hpp"
  39 #include "memory/oopFactory.hpp"
  40 #include "memory/resourceArea.hpp"
  41 #include "oops/array.inline.hpp"
  42 #include "oops/constantPool.inline.hpp"
  43 #include "oops/cpCache.inline.hpp"
  44 #include "oops/instanceKlass.hpp"
  45 #include "oops/objArrayKlass.hpp"
  46 #include "oops/objArrayOop.inline.hpp"
  47 #include "oops/oop.inline.hpp"
  48 #include "oops/typeArrayOop.inline.hpp"
  49 #include "runtime/fieldType.hpp"
  50 #include "runtime/handles.inline.hpp"
  51 #include "runtime/init.hpp"
  52 #include "runtime/javaCalls.hpp"
  53 #include "runtime/signature.hpp"
  54 #include "runtime/vframe.inline.hpp"
  55 #include "utilities/copy.hpp"
  56 
  57 constantTag ConstantPool::tag_at(int which) const { return (constantTag)tags()->at_acquire(which); }
  58 
  59 void ConstantPool::release_tag_at_put(int which, jbyte t) { tags()->release_at_put(which, t); }
  60 
  61 ConstantPool* ConstantPool::allocate(ClassLoaderData* loader_data, int length, TRAPS) {
  62   Array<u1>* tags = MetadataFactory::new_array<u1>(loader_data, length, 0, CHECK_NULL);
  63   int size = ConstantPool::size(length);
  64   return new (loader_data, size, MetaspaceObj::ConstantPoolType, THREAD) ConstantPool(tags);
  65 }
  66 
  67 #ifdef ASSERT
  68 
  69 // MetaspaceObj allocation invariant is calloc equivalent memory
  70 // simple verification of this here (JVM_CONSTANT_Invalid == 0 )
  71 static bool tag_array_is_zero_initialized(Array<u1>* tags) {
  72   assert(tags != NULL, "invariant");
  73   const int length = tags->length();
  74   for (int index = 0; index < length; ++index) {
  75     if (JVM_CONSTANT_Invalid != tags->at(index)) {
  76       return false;
  77     }
  78   }
  79   return true;
  80 }
  81 
  82 #endif
  83 
  84 ConstantPool::ConstantPool(Array<u1>* tags) :
  85   _tags(tags),
  86   _length(tags->length()) {
  87 
  88     assert(_tags != NULL, "invariant");
  89     assert(tags->length() == _length, "invariant");
  90     assert(tag_array_is_zero_initialized(tags), "invariant");
  91     assert(0 == flags(), "invariant");
  92     assert(0 == version(), "invariant");
  93     assert(NULL == _pool_holder, "invariant");
  94 }
  95 
  96 void ConstantPool::deallocate_contents(ClassLoaderData* loader_data) {
  97   if (cache() != NULL) {
  98     MetadataFactory::free_metadata(loader_data, cache());
  99     set_cache(NULL);
 100   }
 101 
 102   MetadataFactory::free_array<Klass*>(loader_data, resolved_klasses());
 103   set_resolved_klasses(NULL);
 104 
 105   MetadataFactory::free_array<jushort>(loader_data, operands());
 106   set_operands(NULL);
 107 
 108   release_C_heap_structures();
 109 
 110   // free tag array
 111   MetadataFactory::free_array<u1>(loader_data, tags());
 112   set_tags(NULL);
 113 }
 114 
 115 void ConstantPool::release_C_heap_structures() {
 116   // walk constant pool and decrement symbol reference counts
 117   unreference_symbols();
 118 }
 119 
 120 void ConstantPool::metaspace_pointers_do(MetaspaceClosure* it) {
 121   log_trace(cds)("Iter(ConstantPool): %p", this);
 122 
 123   it->push(&_tags, MetaspaceClosure::_writable);
 124   it->push(&_cache);
 125   it->push(&_pool_holder);
 126   it->push(&_operands);
 127   it->push(&_resolved_klasses, MetaspaceClosure::_writable);
 128 
 129   for (int i = 0; i < length(); i++) {
 130     // The only MSO's embedded in the CP entries are Symbols:
 131     //   JVM_CONSTANT_String (normal and pseudo)
 132     //   JVM_CONSTANT_Utf8
 133     constantTag ctag = tag_at(i);
 134     if (ctag.is_string() || ctag.is_utf8()) {
 135       it->push(symbol_at_addr(i));
 136     }
 137   }
 138 }
 139 
 140 objArrayOop ConstantPool::resolved_references() const {
 141   return (objArrayOop)_cache->resolved_references();
 142 }
 143 
 144 // Called from outside constant pool resolution where a resolved_reference array
 145 // may not be present.
 146 objArrayOop ConstantPool::resolved_references_or_null() const {
 147   if (_cache == NULL) {
 148     return NULL;
 149   } else {
 150     return (objArrayOop)_cache->resolved_references();
 151   }
 152 }
 153 
 154 // Create resolved_references array and mapping array for original cp indexes
 155 // The ldc bytecode was rewritten to have the resolved reference array index so need a way
 156 // to map it back for resolving and some unlikely miscellaneous uses.
 157 // The objects created by invokedynamic are appended to this list.
 158 void ConstantPool::initialize_resolved_references(ClassLoaderData* loader_data,
 159                                                   const intStack& reference_map,
 160                                                   int constant_pool_map_length,
 161                                                   TRAPS) {
 162   // Initialized the resolved object cache.
 163   int map_length = reference_map.length();
 164   if (map_length > 0) {
 165     // Only need mapping back to constant pool entries.  The map isn't used for
 166     // invokedynamic resolved_reference entries.  For invokedynamic entries,
 167     // the constant pool cache index has the mapping back to both the constant
 168     // pool and to the resolved reference index.
 169     if (constant_pool_map_length > 0) {
 170       Array<u2>* om = MetadataFactory::new_array<u2>(loader_data, constant_pool_map_length, CHECK);
 171 
 172       for (int i = 0; i < constant_pool_map_length; i++) {
 173         int x = reference_map.at(i);
 174         assert(x == (int)(jushort) x, "klass index is too big");
 175         om->at_put(i, (jushort)x);
 176       }
 177       set_reference_map(om);
 178     }
 179 
 180     // Create Java array for holding resolved strings, methodHandles,
 181     // methodTypes, invokedynamic and invokehandle appendix objects, etc.
 182     objArrayOop stom = oopFactory::new_objArray(SystemDictionary::Object_klass(), map_length, CHECK);
 183     Handle refs_handle (THREAD, (oop)stom);  // must handleize.
 184     set_resolved_references(loader_data->add_handle(refs_handle));
 185   }
 186 }
 187 
 188 void ConstantPool::allocate_resolved_klasses(ClassLoaderData* loader_data, int num_klasses, TRAPS) {
 189   // A ConstantPool can't possibly have 0xffff valid class entries,
 190   // because entry #0 must be CONSTANT_Invalid, and each class entry must refer to a UTF8
 191   // entry for the class's name. So at most we will have 0xfffe class entries.
 192   // This allows us to use 0xffff (ConstantPool::_temp_resolved_klass_index) to indicate
 193   // UnresolvedKlass entries that are temporarily created during class redefinition.
 194   assert(num_klasses < CPKlassSlot::_temp_resolved_klass_index, "sanity");
 195   assert(resolved_klasses() == NULL, "sanity");
 196   Array<Klass*>* rk = MetadataFactory::new_array<Klass*>(loader_data, num_klasses, CHECK);
 197   set_resolved_klasses(rk);
 198 }
 199 
 200 void ConstantPool::initialize_unresolved_klasses(ClassLoaderData* loader_data, TRAPS) {
 201   int len = length();
 202   int num_klasses = 0;
 203   for (int i = 1; i <len; i++) {
 204     switch (tag_at(i).value()) {
 205     case JVM_CONSTANT_ClassIndex:
 206       {
 207         const int class_index = klass_index_at(i);
 208         unresolved_klass_at_put(i, class_index, num_klasses++);
 209       }
 210       break;
 211 #ifndef PRODUCT
 212     case JVM_CONSTANT_Class:
 213     case JVM_CONSTANT_UnresolvedClass:
 214     case JVM_CONSTANT_UnresolvedClassInError:
 215       // All of these should have been reverted back to ClassIndex before calling
 216       // this function.
 217       ShouldNotReachHere();
 218 #endif
 219     }
 220   }
 221   allocate_resolved_klasses(loader_data, num_klasses, THREAD);
 222 }
 223 
 224 // Anonymous class support:
 225 void ConstantPool::klass_at_put(int class_index, int name_index, int resolved_klass_index, Klass* k, Symbol* name) {
 226   assert(is_within_bounds(class_index), "index out of bounds");
 227   assert(is_within_bounds(name_index), "index out of bounds");
 228   assert((resolved_klass_index & 0xffff0000) == 0, "must be");
 229   *int_at_addr(class_index) =
 230     build_int_from_shorts((jushort)resolved_klass_index, (jushort)name_index);
 231 
 232   symbol_at_put(name_index, name);
 233   name->increment_refcount();
 234   Klass** adr = resolved_klasses()->adr_at(resolved_klass_index);
 235   OrderAccess::release_store(adr, k);
 236 
 237   // The interpreter assumes when the tag is stored, the klass is resolved
 238   // and the Klass* non-NULL, so we need hardware store ordering here.
 239   if (k != NULL) {
 240     release_tag_at_put(class_index, JVM_CONSTANT_Class);
 241   } else {
 242     release_tag_at_put(class_index, JVM_CONSTANT_UnresolvedClass);
 243   }
 244 }
 245 
 246 // Anonymous class support:
 247 void ConstantPool::klass_at_put(int class_index, Klass* k) {
 248   assert(k != NULL, "must be valid klass");
 249   CPKlassSlot kslot = klass_slot_at(class_index);
 250   int resolved_klass_index = kslot.resolved_klass_index();
 251   Klass** adr = resolved_klasses()->adr_at(resolved_klass_index);
 252   OrderAccess::release_store(adr, k);
 253 
 254   // The interpreter assumes when the tag is stored, the klass is resolved
 255   // and the Klass* non-NULL, so we need hardware store ordering here.
 256   release_tag_at_put(class_index, JVM_CONSTANT_Class);
 257 }
 258 
 259 #if INCLUDE_CDS_JAVA_HEAP
 260 // Archive the resolved references
 261 void ConstantPool::archive_resolved_references(Thread* THREAD) {
 262   if (_cache == NULL) {
 263     return; // nothing to do
 264   }
 265 
 266   InstanceKlass *ik = pool_holder();
 267   if (!(ik->is_shared_boot_class() || ik->is_shared_platform_class() ||
 268         ik->is_shared_app_class())) {
 269     // Archiving resolved references for classes from non-builtin loaders
 270     // is not yet supported.
 271     set_resolved_references(NULL);
 272     return;
 273   }
 274 
 275   objArrayOop rr = resolved_references();
 276   Array<u2>* ref_map = reference_map();
 277   if (rr != NULL) {
 278     int ref_map_len = ref_map == NULL ? 0 : ref_map->length();
 279     int rr_len = rr->length();
 280     for (int i = 0; i < rr_len; i++) {
 281       oop p = rr->obj_at(i);
 282       rr->obj_at_put(i, NULL);
 283       if (p != NULL && i < ref_map_len) {
 284         int index = object_to_cp_index(i);
 285         // Skip the entry if the string hash code is 0 since the string
 286         // is not included in the shared string_table, see StringTable::copy_shared_string.
 287         if (tag_at(index).is_string() && java_lang_String::hash_code(p) != 0) {
 288           oop op = StringTable::create_archived_string(p, THREAD);
 289           // If the String object is not archived (possibly too large),
 290           // NULL is returned. Also set it in the array, so we won't
 291           // have a 'bad' reference in the archived resolved_reference
 292           // array.
 293           rr->obj_at_put(i, op);
 294         }
 295       }
 296     }
 297 
 298     oop archived = MetaspaceShared::archive_heap_object(rr, THREAD);
 299     // If the resolved references array is not archived (too large),
 300     // the 'archived' object is NULL. No need to explicitly check
 301     // the return value of archive_heap_object here. At runtime, the
 302     // resolved references will be created using the normal process
 303     // when there is no archived value.
 304     _cache->set_archived_references(archived);
 305     set_resolved_references(NULL);
 306   }
 307 }
 308 
 309 void ConstantPool::resolve_class_constants(TRAPS) {
 310   assert(DumpSharedSpaces, "used during dump time only");
 311   // The _cache may be NULL if the _pool_holder klass fails verification
 312   // at dump time due to missing dependencies.
 313   if (cache() == NULL || reference_map() == NULL) {
 314     return; // nothing to do
 315   }
 316 
 317   constantPoolHandle cp(THREAD, this);
 318   for (int index = 1; index < length(); index++) { // Index 0 is unused
 319     if (tag_at(index).is_string() && !cp->is_pseudo_string_at(index)) {
 320       int cache_index = cp->cp_to_object_index(index);
 321       string_at_impl(cp, index, cache_index, CHECK);
 322     }
 323   }
 324 }
 325 #endif
 326 
 327 // CDS support. Create a new resolved_references array.
 328 void ConstantPool::restore_unshareable_info(TRAPS) {
 329   assert(is_constantPool(), "ensure C++ vtable is restored");
 330   assert(on_stack(), "should always be set for shared constant pools");
 331   assert(is_shared(), "should always be set for shared constant pools");
 332   assert(_cache != NULL, "constant pool _cache should not be NULL");
 333 
 334   // Only create the new resolved references array if it hasn't been attempted before
 335   if (resolved_references() != NULL) return;
 336 
 337   // restore the C++ vtable from the shared archive
 338   restore_vtable();
 339 
 340   if (SystemDictionary::Object_klass_loaded()) {
 341     ClassLoaderData* loader_data = pool_holder()->class_loader_data();
 342 #if INCLUDE_CDS_JAVA_HEAP
 343     if (MetaspaceShared::open_archive_heap_region_mapped() &&
 344         _cache->archived_references() != NULL) {
 345       oop archived = _cache->archived_references();
 346       // Create handle for the archived resolved reference array object
 347       Handle refs_handle(THREAD, archived);
 348       set_resolved_references(loader_data->add_handle(refs_handle));
 349     } else
 350 #endif
 351     {
 352       // No mapped archived resolved reference array
 353       // Recreate the object array and add to ClassLoaderData.
 354       int map_length = resolved_reference_length();
 355       if (map_length > 0) {
 356         objArrayOop stom = oopFactory::new_objArray(SystemDictionary::Object_klass(), map_length, CHECK);
 357         Handle refs_handle(THREAD, (oop)stom);  // must handleize.
 358         set_resolved_references(loader_data->add_handle(refs_handle));
 359       }
 360     }
 361   }
 362 }
 363 
 364 void ConstantPool::remove_unshareable_info() {
 365   // Resolved references are not in the shared archive.
 366   // Save the length for restoration.  It is not necessarily the same length
 367   // as reference_map.length() if invokedynamic is saved. It is needed when
 368   // re-creating the resolved reference array if archived heap data cannot be map
 369   // at runtime.
 370   set_resolved_reference_length(
 371     resolved_references() != NULL ? resolved_references()->length() : 0);
 372 
 373   // If archiving heap objects is not allowed, clear the resolved references.
 374   // Otherwise, it is cleared after the resolved references array is cached
 375   // (see archive_resolved_references()).
 376   if (!MetaspaceShared::is_heap_object_archiving_allowed()) {
 377     set_resolved_references(NULL);
 378   }
 379 
 380   // Shared ConstantPools are in the RO region, so the _flags cannot be modified.
 381   // The _on_stack flag is used to prevent ConstantPools from deallocation during
 382   // class redefinition. Since shared ConstantPools cannot be deallocated anyway,
 383   // we always set _on_stack to true to avoid having to change _flags during runtime.
 384   _flags |= (_on_stack | _is_shared);
 385   int num_klasses = 0;
 386   for (int index = 1; index < length(); index++) { // Index 0 is unused
 387     assert(!tag_at(index).is_unresolved_klass_in_error(), "This must not happen during dump time");
 388     if (tag_at(index).is_klass()) {
 389       // This class was resolved as a side effect of executing Java code
 390       // during dump time. We need to restore it back to an UnresolvedClass,
 391       // so that the proper class loading and initialization can happen
 392       // at runtime.
 393       CPKlassSlot kslot = klass_slot_at(index);
 394       int resolved_klass_index = kslot.resolved_klass_index();
 395       int name_index = kslot.name_index();
 396       assert(tag_at(name_index).is_symbol(), "sanity");
 397       resolved_klasses()->at_put(resolved_klass_index, NULL);
 398       tag_at_put(index, JVM_CONSTANT_UnresolvedClass);
 399       assert(klass_name_at(index) == symbol_at(name_index), "sanity");
 400     }
 401   }
 402   if (cache() != NULL) {
 403     cache()->remove_unshareable_info();
 404   }
 405 }
 406 
 407 int ConstantPool::cp_to_object_index(int cp_index) {
 408   // this is harder don't do this so much.
 409   int i = reference_map()->find(cp_index);
 410   // We might not find the index for jsr292 call.
 411   return (i < 0) ? _no_index_sentinel : i;
 412 }
 413 
 414 void ConstantPool::string_at_put(int which, int obj_index, oop str) {
 415   resolved_references()->obj_at_put(obj_index, str);
 416 }
 417 
 418 void ConstantPool::trace_class_resolution(const constantPoolHandle& this_cp, Klass* k) {
 419   ResourceMark rm;
 420   int line_number = -1;
 421   const char * source_file = NULL;
 422   if (JavaThread::current()->has_last_Java_frame()) {
 423     // try to identify the method which called this function.
 424     vframeStream vfst(JavaThread::current());
 425     if (!vfst.at_end()) {
 426       line_number = vfst.method()->line_number_from_bci(vfst.bci());
 427       Symbol* s = vfst.method()->method_holder()->source_file_name();
 428       if (s != NULL) {
 429         source_file = s->as_C_string();
 430       }
 431     }
 432   }
 433   if (k != this_cp->pool_holder()) {
 434     // only print something if the classes are different
 435     if (source_file != NULL) {
 436       log_debug(class, resolve)("%s %s %s:%d",
 437                  this_cp->pool_holder()->external_name(),
 438                  k->external_name(), source_file, line_number);
 439     } else {
 440       log_debug(class, resolve)("%s %s",
 441                  this_cp->pool_holder()->external_name(),
 442                  k->external_name());
 443     }
 444   }
 445 }
 446 
 447 Klass* ConstantPool::klass_at_impl(const constantPoolHandle& this_cp, int which,
 448                                    bool save_resolution_error, TRAPS) {
 449   assert(THREAD->is_Java_thread(), "must be a Java thread");
 450 
 451   // A resolved constantPool entry will contain a Klass*, otherwise a Symbol*.
 452   // It is not safe to rely on the tag bit's here, since we don't have a lock, and
 453   // the entry and tag is not updated atomicly.
 454   CPKlassSlot kslot = this_cp->klass_slot_at(which);
 455   int resolved_klass_index = kslot.resolved_klass_index();
 456   int name_index = kslot.name_index();
 457   assert(this_cp->tag_at(name_index).is_symbol(), "sanity");
 458 
 459   Klass* klass = this_cp->resolved_klasses()->at(resolved_klass_index);
 460   if (klass != NULL) {
 461     return klass;
 462   }
 463 
 464   // This tag doesn't change back to unresolved class unless at a safepoint.
 465   if (this_cp->tag_at(which).is_unresolved_klass_in_error()) {
 466     // The original attempt to resolve this constant pool entry failed so find the
 467     // class of the original error and throw another error of the same class
 468     // (JVMS 5.4.3).
 469     // If there is a detail message, pass that detail message to the error.
 470     // The JVMS does not strictly require us to duplicate the same detail message,
 471     // or any internal exception fields such as cause or stacktrace.  But since the
 472     // detail message is often a class name or other literal string, we will repeat it
 473     // if we can find it in the symbol table.
 474     throw_resolution_error(this_cp, which, CHECK_0);
 475     ShouldNotReachHere();
 476   }
 477 
 478   Handle mirror_handle;
 479   Symbol* name = this_cp->symbol_at(name_index);
 480   Handle loader (THREAD, this_cp->pool_holder()->class_loader());
 481   Handle protection_domain (THREAD, this_cp->pool_holder()->protection_domain());
 482   Klass* k = SystemDictionary::resolve_or_fail(name, loader, protection_domain, true, THREAD);
 483   if (!HAS_PENDING_EXCEPTION) {
 484     // preserve the resolved klass from unloading
 485     mirror_handle = Handle(THREAD, k->java_mirror());
 486     // Do access check for klasses
 487     verify_constant_pool_resolve(this_cp, k, THREAD);
 488   }
 489 
 490   // Failed to resolve class. We must record the errors so that subsequent attempts
 491   // to resolve this constant pool entry fail with the same error (JVMS 5.4.3).
 492   if (HAS_PENDING_EXCEPTION) {
 493     if (save_resolution_error) {
 494       save_and_throw_exception(this_cp, which, constantTag(JVM_CONSTANT_UnresolvedClass), CHECK_NULL);
 495       // If CHECK_NULL above doesn't return the exception, that means that
 496       // some other thread has beaten us and has resolved the class.
 497       // To preserve old behavior, we return the resolved class.
 498       klass = this_cp->resolved_klasses()->at(resolved_klass_index);
 499       assert(klass != NULL, "must be resolved if exception was cleared");
 500       return klass;
 501     } else {
 502       return NULL;  // return the pending exception
 503     }
 504   }
 505 
 506   // Make this class loader depend upon the class loader owning the class reference
 507   ClassLoaderData* this_key = this_cp->pool_holder()->class_loader_data();
 508   this_key->record_dependency(k);
 509 
 510   // logging for class+resolve.
 511   if (log_is_enabled(Debug, class, resolve)){
 512     trace_class_resolution(this_cp, k);
 513   }
 514   Klass** adr = this_cp->resolved_klasses()->adr_at(resolved_klass_index);
 515   OrderAccess::release_store(adr, k);
 516   // The interpreter assumes when the tag is stored, the klass is resolved
 517   // and the Klass* stored in _resolved_klasses is non-NULL, so we need
 518   // hardware store ordering here.
 519   this_cp->release_tag_at_put(which, JVM_CONSTANT_Class);
 520   return k;
 521 }
 522 
 523 
 524 // Does not update ConstantPool* - to avoid any exception throwing. Used
 525 // by compiler and exception handling.  Also used to avoid classloads for
 526 // instanceof operations. Returns NULL if the class has not been loaded or
 527 // if the verification of constant pool failed
 528 Klass* ConstantPool::klass_at_if_loaded(const constantPoolHandle& this_cp, int which) {
 529   CPKlassSlot kslot = this_cp->klass_slot_at(which);
 530   int resolved_klass_index = kslot.resolved_klass_index();
 531   int name_index = kslot.name_index();
 532   assert(this_cp->tag_at(name_index).is_symbol(), "sanity");
 533 
 534   Klass* k = this_cp->resolved_klasses()->at(resolved_klass_index);
 535   if (k != NULL) {
 536     return k;
 537   } else {
 538     Thread *thread = Thread::current();
 539     Symbol* name = this_cp->symbol_at(name_index);
 540     oop loader = this_cp->pool_holder()->class_loader();
 541     oop protection_domain = this_cp->pool_holder()->protection_domain();
 542     Handle h_prot (thread, protection_domain);
 543     Handle h_loader (thread, loader);
 544     Klass* k = SystemDictionary::find(name, h_loader, h_prot, thread);
 545 
 546     if (k != NULL) {
 547       // Make sure that resolving is legal
 548       EXCEPTION_MARK;
 549       // return NULL if verification fails
 550       verify_constant_pool_resolve(this_cp, k, THREAD);
 551       if (HAS_PENDING_EXCEPTION) {
 552         CLEAR_PENDING_EXCEPTION;
 553         return NULL;
 554       }
 555       return k;
 556     } else {
 557       return k;
 558     }
 559   }
 560 }
 561 
 562 Method* ConstantPool::method_at_if_loaded(const constantPoolHandle& cpool,
 563                                                    int which) {
 564   if (cpool->cache() == NULL)  return NULL;  // nothing to load yet
 565   int cache_index = decode_cpcache_index(which, true);
 566   if (!(cache_index >= 0 && cache_index < cpool->cache()->length())) {
 567     // FIXME: should be an assert
 568     log_debug(class, resolve)("bad operand %d in:", which); cpool->print();
 569     return NULL;
 570   }
 571   ConstantPoolCacheEntry* e = cpool->cache()->entry_at(cache_index);
 572   return e->method_if_resolved(cpool);
 573 }
 574 
 575 
 576 bool ConstantPool::has_appendix_at_if_loaded(const constantPoolHandle& cpool, int which) {
 577   if (cpool->cache() == NULL)  return false;  // nothing to load yet
 578   int cache_index = decode_cpcache_index(which, true);
 579   ConstantPoolCacheEntry* e = cpool->cache()->entry_at(cache_index);
 580   return e->has_appendix();
 581 }
 582 
 583 oop ConstantPool::appendix_at_if_loaded(const constantPoolHandle& cpool, int which) {
 584   if (cpool->cache() == NULL)  return NULL;  // nothing to load yet
 585   int cache_index = decode_cpcache_index(which, true);
 586   ConstantPoolCacheEntry* e = cpool->cache()->entry_at(cache_index);
 587   return e->appendix_if_resolved(cpool);
 588 }
 589 
 590 
 591 bool ConstantPool::has_method_type_at_if_loaded(const constantPoolHandle& cpool, int which) {
 592   if (cpool->cache() == NULL)  return false;  // nothing to load yet
 593   int cache_index = decode_cpcache_index(which, true);
 594   ConstantPoolCacheEntry* e = cpool->cache()->entry_at(cache_index);
 595   return e->has_method_type();
 596 }
 597 
 598 oop ConstantPool::method_type_at_if_loaded(const constantPoolHandle& cpool, int which) {
 599   if (cpool->cache() == NULL)  return NULL;  // nothing to load yet
 600   int cache_index = decode_cpcache_index(which, true);
 601   ConstantPoolCacheEntry* e = cpool->cache()->entry_at(cache_index);
 602   return e->method_type_if_resolved(cpool);
 603 }
 604 
 605 
 606 Symbol* ConstantPool::impl_name_ref_at(int which, bool uncached) {
 607   int name_index = name_ref_index_at(impl_name_and_type_ref_index_at(which, uncached));
 608   return symbol_at(name_index);
 609 }
 610 
 611 
 612 Symbol* ConstantPool::impl_signature_ref_at(int which, bool uncached) {
 613   int signature_index = signature_ref_index_at(impl_name_and_type_ref_index_at(which, uncached));
 614   return symbol_at(signature_index);
 615 }
 616 
 617 int ConstantPool::impl_name_and_type_ref_index_at(int which, bool uncached) {
 618   int i = which;
 619   if (!uncached && cache() != NULL) {
 620     if (ConstantPool::is_invokedynamic_index(which)) {
 621       // Invokedynamic index is index into the constant pool cache
 622       int pool_index = invokedynamic_cp_cache_entry_at(which)->constant_pool_index();
 623       pool_index = invoke_dynamic_name_and_type_ref_index_at(pool_index);
 624       assert(tag_at(pool_index).is_name_and_type(), "");
 625       return pool_index;
 626     }
 627     // change byte-ordering and go via cache
 628     i = remap_instruction_operand_from_cache(which);
 629   } else {
 630     if (tag_at(which).is_invoke_dynamic() ||
 631         tag_at(which).is_dynamic_constant() ||
 632         tag_at(which).is_dynamic_constant_in_error()) {
 633       int pool_index = invoke_dynamic_name_and_type_ref_index_at(which);
 634       assert(tag_at(pool_index).is_name_and_type(), "");
 635       return pool_index;
 636     }
 637   }
 638   assert(tag_at(i).is_field_or_method(), "Corrupted constant pool");
 639   assert(!tag_at(i).is_invoke_dynamic() &&
 640          !tag_at(i).is_dynamic_constant() &&
 641          !tag_at(i).is_dynamic_constant_in_error(), "Must be handled above");
 642   jint ref_index = *int_at_addr(i);
 643   return extract_high_short_from_int(ref_index);
 644 }
 645 
 646 constantTag ConstantPool::impl_tag_ref_at(int which, bool uncached) {
 647   int pool_index = which;
 648   if (!uncached && cache() != NULL) {
 649     if (ConstantPool::is_invokedynamic_index(which)) {
 650       // Invokedynamic index is index into resolved_references
 651       pool_index = invokedynamic_cp_cache_entry_at(which)->constant_pool_index();
 652     } else {
 653       // change byte-ordering and go via cache
 654       pool_index = remap_instruction_operand_from_cache(which);
 655     }
 656   }
 657   return tag_at(pool_index);
 658 }
 659 
 660 int ConstantPool::impl_klass_ref_index_at(int which, bool uncached) {
 661   guarantee(!ConstantPool::is_invokedynamic_index(which),
 662             "an invokedynamic instruction does not have a klass");
 663   int i = which;
 664   if (!uncached && cache() != NULL) {
 665     // change byte-ordering and go via cache
 666     i = remap_instruction_operand_from_cache(which);
 667   }
 668   assert(tag_at(i).is_field_or_method(), "Corrupted constant pool");
 669   jint ref_index = *int_at_addr(i);
 670   return extract_low_short_from_int(ref_index);
 671 }
 672 
 673 
 674 
 675 int ConstantPool::remap_instruction_operand_from_cache(int operand) {
 676   int cpc_index = operand;
 677   DEBUG_ONLY(cpc_index -= CPCACHE_INDEX_TAG);
 678   assert((int)(u2)cpc_index == cpc_index, "clean u2");
 679   int member_index = cache()->entry_at(cpc_index)->constant_pool_index();
 680   return member_index;
 681 }
 682 
 683 
 684 void ConstantPool::verify_constant_pool_resolve(const constantPoolHandle& this_cp, Klass* k, TRAPS) {
 685   if (!(k->is_instance_klass() || k->is_objArray_klass())) {
 686     return;  // short cut, typeArray klass is always accessible
 687   }
 688   Klass* holder = this_cp->pool_holder();
 689   bool fold_type_to_class = true;
 690   LinkResolver::check_klass_accessability(holder, k, fold_type_to_class, CHECK);
 691 }
 692 
 693 
 694 int ConstantPool::name_ref_index_at(int which_nt) {
 695   jint ref_index = name_and_type_at(which_nt);
 696   return extract_low_short_from_int(ref_index);
 697 }
 698 
 699 
 700 int ConstantPool::signature_ref_index_at(int which_nt) {
 701   jint ref_index = name_and_type_at(which_nt);
 702   return extract_high_short_from_int(ref_index);
 703 }
 704 
 705 
 706 Klass* ConstantPool::klass_ref_at(int which, TRAPS) {
 707   return klass_at(klass_ref_index_at(which), THREAD);
 708 }
 709 
 710 Symbol* ConstantPool::klass_name_at(int which) const {
 711   return symbol_at(klass_slot_at(which).name_index());
 712 }
 713 
 714 Symbol* ConstantPool::klass_ref_at_noresolve(int which) {
 715   jint ref_index = klass_ref_index_at(which);
 716   return klass_at_noresolve(ref_index);
 717 }
 718 
 719 Symbol* ConstantPool::uncached_klass_ref_at_noresolve(int which) {
 720   jint ref_index = uncached_klass_ref_index_at(which);
 721   return klass_at_noresolve(ref_index);
 722 }
 723 
 724 char* ConstantPool::string_at_noresolve(int which) {
 725   return unresolved_string_at(which)->as_C_string();
 726 }
 727 
 728 BasicType ConstantPool::basic_type_for_signature_at(int which) const {
 729   return FieldType::basic_type(symbol_at(which));
 730 }
 731 
 732 
 733 void ConstantPool::resolve_string_constants_impl(const constantPoolHandle& this_cp, TRAPS) {
 734   for (int index = 1; index < this_cp->length(); index++) { // Index 0 is unused
 735     if (this_cp->tag_at(index).is_string()) {
 736       this_cp->string_at(index, CHECK);
 737     }
 738   }
 739 }
 740 
 741 Symbol* ConstantPool::exception_message(const constantPoolHandle& this_cp, int which, constantTag tag, oop pending_exception) {
 742   // Dig out the detailed message to reuse if possible
 743   Symbol* message = java_lang_Throwable::detail_message(pending_exception);
 744   if (message != NULL) {
 745     return message;
 746   }
 747 
 748   // Return specific message for the tag
 749   switch (tag.value()) {
 750   case JVM_CONSTANT_UnresolvedClass:
 751     // return the class name in the error message
 752     message = this_cp->klass_name_at(which);
 753     break;
 754   case JVM_CONSTANT_MethodHandle:
 755     // return the method handle name in the error message
 756     message = this_cp->method_handle_name_ref_at(which);
 757     break;
 758   case JVM_CONSTANT_MethodType:
 759     // return the method type signature in the error message
 760     message = this_cp->method_type_signature_at(which);
 761     break;
 762   default:
 763     ShouldNotReachHere();
 764   }
 765 
 766   return message;
 767 }
 768 
 769 void ConstantPool::throw_resolution_error(const constantPoolHandle& this_cp, int which, TRAPS) {
 770   Symbol* message = NULL;
 771   Symbol* error = SystemDictionary::find_resolution_error(this_cp, which, &message);
 772   assert(error != NULL && message != NULL, "checking");
 773   CLEAR_PENDING_EXCEPTION;
 774   ResourceMark rm;
 775   THROW_MSG(error, message->as_C_string());
 776 }
 777 
 778 // If resolution for Class, Dynamic constant, MethodHandle or MethodType fails, save the
 779 // exception in the resolution error table, so that the same exception is thrown again.
 780 void ConstantPool::save_and_throw_exception(const constantPoolHandle& this_cp, int which,
 781                                             constantTag tag, TRAPS) {
 782   Symbol* error = PENDING_EXCEPTION->klass()->name();
 783 
 784   int error_tag = tag.error_value();
 785 
 786   if (!PENDING_EXCEPTION->
 787     is_a(SystemDictionary::LinkageError_klass())) {
 788     // Just throw the exception and don't prevent these classes from
 789     // being loaded due to virtual machine errors like StackOverflow
 790     // and OutOfMemoryError, etc, or if the thread was hit by stop()
 791     // Needs clarification to section 5.4.3 of the VM spec (see 6308271)
 792   } else if (this_cp->tag_at(which).value() != error_tag) {
 793     Symbol* message = exception_message(this_cp, which, tag, PENDING_EXCEPTION);
 794     SystemDictionary::add_resolution_error(this_cp, which, error, message);
 795     // CAS in the tag.  If a thread beat us to registering this error that's fine.
 796     // If another thread resolved the reference, this is a race condition. This
 797     // thread may have had a security manager or something temporary.
 798     // This doesn't deterministically get an error.   So why do we save this?
 799     // We save this because jvmti can add classes to the bootclass path after
 800     // this error, so it needs to get the same error if the error is first.
 801     jbyte old_tag = Atomic::cmpxchg((jbyte)error_tag,
 802                             (jbyte*)this_cp->tag_addr_at(which), (jbyte)tag.value());
 803     if (old_tag != error_tag && old_tag != tag.value()) {
 804       // MethodHandles and MethodType doesn't change to resolved version.
 805       assert(this_cp->tag_at(which).is_klass(), "Wrong tag value");
 806       // Forget the exception and use the resolved class.
 807       CLEAR_PENDING_EXCEPTION;
 808     }
 809   } else {
 810     // some other thread put this in error state
 811     throw_resolution_error(this_cp, which, CHECK);
 812   }
 813 }
 814 
 815 constantTag ConstantPool::constant_tag_at(int which) {
 816   constantTag tag = tag_at(which);
 817   if (tag.is_dynamic_constant() ||
 818       tag.is_dynamic_constant_in_error()) {
 819     // have to look at the signature for this one
 820     Symbol* constant_type = uncached_signature_ref_at(which);
 821     return constantTag::ofBasicType(FieldType::basic_type(constant_type));
 822   }
 823   return tag;
 824 }
 825 
 826 BasicType ConstantPool::basic_type_for_constant_at(int which) {
 827   constantTag tag = tag_at(which);
 828   if (tag.is_dynamic_constant() ||
 829       tag.is_dynamic_constant_in_error()) {
 830     // have to look at the signature for this one
 831     Symbol* constant_type = uncached_signature_ref_at(which);
 832     return FieldType::basic_type(constant_type);
 833   }
 834   return tag.basic_type();
 835 }
 836 
 837 // Called to resolve constants in the constant pool and return an oop.
 838 // Some constant pool entries cache their resolved oop. This is also
 839 // called to create oops from constants to use in arguments for invokedynamic
 840 oop ConstantPool::resolve_constant_at_impl(const constantPoolHandle& this_cp,
 841                                            int index, int cache_index,
 842                                            bool* status_return, TRAPS) {
 843   oop result_oop = NULL;
 844   Handle throw_exception;
 845 
 846   if (cache_index == _possible_index_sentinel) {
 847     // It is possible that this constant is one which is cached in the objects.
 848     // We'll do a linear search.  This should be OK because this usage is rare.
 849     // FIXME: If bootstrap specifiers stress this code, consider putting in
 850     // a reverse index.  Binary search over a short array should do it.
 851     assert(index > 0, "valid index");
 852     cache_index = this_cp->cp_to_object_index(index);
 853   }
 854   assert(cache_index == _no_index_sentinel || cache_index >= 0, "");
 855   assert(index == _no_index_sentinel || index >= 0, "");
 856 
 857   if (cache_index >= 0) {
 858     result_oop = this_cp->resolved_references()->obj_at(cache_index);
 859     if (result_oop != NULL) {
 860       if (oopDesc::equals(result_oop, Universe::the_null_sentinel())) {
 861         DEBUG_ONLY(int temp_index = (index >= 0 ? index : this_cp->object_to_cp_index(cache_index)));
 862         assert(this_cp->tag_at(temp_index).is_dynamic_constant(), "only condy uses the null sentinel");
 863         result_oop = NULL;
 864       }
 865       if (status_return != NULL)  (*status_return) = true;
 866       return result_oop;
 867       // That was easy...
 868     }
 869     index = this_cp->object_to_cp_index(cache_index);
 870   }
 871 
 872   jvalue prim_value;  // temp used only in a few cases below
 873 
 874   constantTag tag = this_cp->tag_at(index);
 875 
 876   if (status_return != NULL) {
 877     // don't trigger resolution if the constant might need it
 878     switch (tag.value()) {
 879     case JVM_CONSTANT_Class:
 880     {
 881       CPKlassSlot kslot = this_cp->klass_slot_at(index);
 882       int resolved_klass_index = kslot.resolved_klass_index();
 883       if (this_cp->resolved_klasses()->at(resolved_klass_index) == NULL) {
 884         (*status_return) = false;
 885         return NULL;
 886       }
 887       // the klass is waiting in the CP; go get it
 888       break;
 889     }
 890     case JVM_CONSTANT_String:
 891     case JVM_CONSTANT_Integer:
 892     case JVM_CONSTANT_Float:
 893     case JVM_CONSTANT_Long:
 894     case JVM_CONSTANT_Double:
 895       // these guys trigger OOM at worst
 896       break;
 897     default:
 898       (*status_return) = false;
 899       return NULL;
 900     }
 901     // from now on there is either success or an OOME
 902     (*status_return) = true;
 903   }
 904 
 905   switch (tag.value()) {
 906 
 907   case JVM_CONSTANT_UnresolvedClass:
 908   case JVM_CONSTANT_UnresolvedClassInError:
 909   case JVM_CONSTANT_Class:
 910     {
 911       assert(cache_index == _no_index_sentinel, "should not have been set");
 912       Klass* resolved = klass_at_impl(this_cp, index, true, CHECK_NULL);
 913       // ldc wants the java mirror.
 914       result_oop = resolved->java_mirror();
 915       break;
 916     }
 917 
 918   case JVM_CONSTANT_Dynamic:
 919     {
 920       Klass* current_klass  = this_cp->pool_holder();
 921       Symbol* constant_name = this_cp->uncached_name_ref_at(index);
 922       Symbol* constant_type = this_cp->uncached_signature_ref_at(index);
 923 
 924       // The initial step in resolving an unresolved symbolic reference to a
 925       // dynamically-computed constant is to resolve the symbolic reference to a
 926       // method handle which will be the bootstrap method for the dynamically-computed
 927       // constant. If resolution of the java.lang.invoke.MethodHandle for the bootstrap
 928       // method fails, then a MethodHandleInError is stored at the corresponding
 929       // bootstrap method's CP index for the CONSTANT_MethodHandle_info. No need to
 930       // set a DynamicConstantInError here since any subsequent use of this
 931       // bootstrap method will encounter the resolution of MethodHandleInError.
 932       oop bsm_info = this_cp->resolve_bootstrap_specifier_at(index, THREAD);
 933       Exceptions::wrap_dynamic_exception(CHECK_NULL);
 934       assert(bsm_info != NULL, "");
 935       // FIXME: Cache this once per BootstrapMethods entry, not once per CONSTANT_Dynamic.
 936       Handle bootstrap_specifier = Handle(THREAD, bsm_info);
 937 
 938       // Resolve the Dynamically-Computed constant to invoke the BSM in order to obtain the resulting oop.
 939       Handle value = SystemDictionary::link_dynamic_constant(current_klass,
 940                                                              index,
 941                                                              bootstrap_specifier,
 942                                                              constant_name,
 943                                                              constant_type,
 944                                                              THREAD);
 945       result_oop = value();
 946       Exceptions::wrap_dynamic_exception(THREAD);
 947       if (HAS_PENDING_EXCEPTION) {
 948         // Resolution failure of the dynamically-computed constant, save_and_throw_exception
 949         // will check for a LinkageError and store a DynamicConstantInError.
 950         save_and_throw_exception(this_cp, index, tag, CHECK_NULL);
 951       }
 952       BasicType type = FieldType::basic_type(constant_type);
 953       if (!is_reference_type(type)) {
 954         // Make sure the primitive value is properly boxed.
 955         // This is a JDK responsibility.
 956         const char* fail = NULL;
 957         if (result_oop == NULL) {
 958           fail = "null result instead of box";
 959         } else if (!is_java_primitive(type)) {
 960           // FIXME: support value types via unboxing
 961           fail = "can only handle references and primitives";
 962         } else if (!java_lang_boxing_object::is_instance(result_oop, type)) {
 963           fail = "primitive is not properly boxed";
 964         }
 965         if (fail != NULL) {
 966           // Since this exception is not a LinkageError, throw exception
 967           // but do not save a DynamicInError resolution result.
 968           // See section 5.4.3 of the VM spec.
 969           THROW_MSG_NULL(vmSymbols::java_lang_InternalError(), fail);
 970         }
 971       }
 972       break;
 973     }
 974 
 975   case JVM_CONSTANT_String:
 976     assert(cache_index != _no_index_sentinel, "should have been set");
 977     if (this_cp->is_pseudo_string_at(index)) {
 978       result_oop = this_cp->pseudo_string_at(index, cache_index);
 979       break;
 980     }
 981     result_oop = string_at_impl(this_cp, index, cache_index, CHECK_NULL);
 982     break;
 983 
 984   case JVM_CONSTANT_DynamicInError:
 985   case JVM_CONSTANT_MethodHandleInError:
 986   case JVM_CONSTANT_MethodTypeInError:
 987     {
 988       throw_resolution_error(this_cp, index, CHECK_NULL);
 989       break;
 990     }
 991 
 992   case JVM_CONSTANT_MethodHandle:
 993     {
 994       int ref_kind                 = this_cp->method_handle_ref_kind_at(index);
 995       int callee_index             = this_cp->method_handle_klass_index_at(index);
 996       Symbol*  name =      this_cp->method_handle_name_ref_at(index);
 997       Symbol*  signature = this_cp->method_handle_signature_ref_at(index);
 998       constantTag m_tag  = this_cp->tag_at(this_cp->method_handle_index_at(index));
 999       { ResourceMark rm(THREAD);
1000         log_debug(class, resolve)("resolve JVM_CONSTANT_MethodHandle:%d [%d/%d/%d] %s.%s",
1001                               ref_kind, index, this_cp->method_handle_index_at(index),
1002                               callee_index, name->as_C_string(), signature->as_C_string());
1003       }
1004 
1005       Klass* callee = klass_at_impl(this_cp, callee_index, true, CHECK_NULL);
1006 
1007       // Check constant pool method consistency
1008       if ((callee->is_interface() && m_tag.is_method()) ||
1009           ((!callee->is_interface() && m_tag.is_interface_method()))) {
1010         ResourceMark rm(THREAD);
1011         char buf[400];
1012         jio_snprintf(buf, sizeof(buf),
1013           "Inconsistent constant pool data in classfile for class %s. "
1014           "Method %s%s at index %d is %s and should be %s",
1015           callee->name()->as_C_string(), name->as_C_string(), signature->as_C_string(), index,
1016           callee->is_interface() ? "CONSTANT_MethodRef" : "CONSTANT_InterfaceMethodRef",
1017           callee->is_interface() ? "CONSTANT_InterfaceMethodRef" : "CONSTANT_MethodRef");
1018         THROW_MSG_NULL(vmSymbols::java_lang_IncompatibleClassChangeError(), buf);
1019       }
1020 
1021       Klass* klass = this_cp->pool_holder();
1022       Handle value = SystemDictionary::link_method_handle_constant(klass, ref_kind,
1023                                                                    callee, name, signature,
1024                                                                    THREAD);
1025       result_oop = value();
1026       if (HAS_PENDING_EXCEPTION) {
1027         save_and_throw_exception(this_cp, index, tag, CHECK_NULL);
1028       }
1029       break;
1030     }
1031 
1032   case JVM_CONSTANT_MethodType:
1033     {
1034       Symbol*  signature = this_cp->method_type_signature_at(index);
1035       { ResourceMark rm(THREAD);
1036         log_debug(class, resolve)("resolve JVM_CONSTANT_MethodType [%d/%d] %s",
1037                               index, this_cp->method_type_index_at(index),
1038                               signature->as_C_string());
1039       }
1040       Klass* klass = this_cp->pool_holder();
1041       Handle value = SystemDictionary::find_method_handle_type(signature, klass, THREAD);
1042       result_oop = value();
1043       if (HAS_PENDING_EXCEPTION) {
1044         save_and_throw_exception(this_cp, index, tag, CHECK_NULL);
1045       }
1046       break;
1047     }
1048 
1049   case JVM_CONSTANT_Integer:
1050     assert(cache_index == _no_index_sentinel, "should not have been set");
1051     prim_value.i = this_cp->int_at(index);
1052     result_oop = java_lang_boxing_object::create(T_INT, &prim_value, CHECK_NULL);
1053     break;
1054 
1055   case JVM_CONSTANT_Float:
1056     assert(cache_index == _no_index_sentinel, "should not have been set");
1057     prim_value.f = this_cp->float_at(index);
1058     result_oop = java_lang_boxing_object::create(T_FLOAT, &prim_value, CHECK_NULL);
1059     break;
1060 
1061   case JVM_CONSTANT_Long:
1062     assert(cache_index == _no_index_sentinel, "should not have been set");
1063     prim_value.j = this_cp->long_at(index);
1064     result_oop = java_lang_boxing_object::create(T_LONG, &prim_value, CHECK_NULL);
1065     break;
1066 
1067   case JVM_CONSTANT_Double:
1068     assert(cache_index == _no_index_sentinel, "should not have been set");
1069     prim_value.d = this_cp->double_at(index);
1070     result_oop = java_lang_boxing_object::create(T_DOUBLE, &prim_value, CHECK_NULL);
1071     break;
1072 
1073   default:
1074     DEBUG_ONLY( tty->print_cr("*** %p: tag at CP[%d/%d] = %d",
1075                               this_cp(), index, cache_index, tag.value()));
1076     assert(false, "unexpected constant tag");
1077     break;
1078   }
1079 
1080   if (cache_index >= 0) {
1081     // Benign race condition:  resolved_references may already be filled in.
1082     // The important thing here is that all threads pick up the same result.
1083     // It doesn't matter which racing thread wins, as long as only one
1084     // result is used by all threads, and all future queries.
1085     oop new_result = (result_oop == NULL ? Universe::the_null_sentinel() : result_oop);
1086     oop old_result = this_cp->resolved_references()
1087       ->atomic_compare_exchange_oop(cache_index, new_result, NULL);
1088     if (old_result == NULL) {
1089       return result_oop;  // was installed
1090     } else {
1091       // Return the winning thread's result.  This can be different than
1092       // the result here for MethodHandles.
1093       if (oopDesc::equals(old_result, Universe::the_null_sentinel()))
1094         old_result = NULL;
1095       return old_result;
1096     }
1097   } else {
1098     assert(!oopDesc::equals(result_oop, Universe::the_null_sentinel()), "");
1099     return result_oop;
1100   }
1101 }
1102 
1103 oop ConstantPool::uncached_string_at(int which, TRAPS) {
1104   Symbol* sym = unresolved_string_at(which);
1105   oop str = StringTable::intern(sym, CHECK_(NULL));
1106   assert(java_lang_String::is_instance(str), "must be string");
1107   return str;
1108 }
1109 
1110 
1111 oop ConstantPool::resolve_bootstrap_specifier_at_impl(const constantPoolHandle& this_cp, int index, TRAPS) {
1112   assert((this_cp->tag_at(index).is_invoke_dynamic() ||
1113           this_cp->tag_at(index).is_dynamic_constant()), "Corrupted constant pool");
1114   Handle bsm;
1115   int argc;
1116   {
1117     // JVM_CONSTANT_InvokeDynamic is an ordered pair of [bootm, name&mtype], plus optional arguments
1118     // JVM_CONSTANT_Dynamic is an ordered pair of [bootm, name&ftype], plus optional arguments
1119     // In both cases, the bootm, being a JVM_CONSTANT_MethodHandle, has its own cache entry.
1120     // It is accompanied by the optional arguments.
1121     int bsm_index = this_cp->invoke_dynamic_bootstrap_method_ref_index_at(index);
1122     oop bsm_oop = this_cp->resolve_possibly_cached_constant_at(bsm_index, CHECK_NULL);
1123     if (!java_lang_invoke_MethodHandle::is_instance(bsm_oop)) {
1124       THROW_MSG_NULL(vmSymbols::java_lang_LinkageError(), "BSM not an MethodHandle");
1125     }
1126 
1127     // Extract the optional static arguments.
1128     argc = this_cp->invoke_dynamic_argument_count_at(index);
1129 
1130     // if there are no static arguments, return the bsm by itself:
1131     if (argc == 0 && UseBootstrapCallInfo < 2)  return bsm_oop;
1132 
1133     bsm = Handle(THREAD, bsm_oop);
1134   }
1135 
1136   // We are going to return an ordered pair of {bsm, info}, using a 2-array.
1137   objArrayHandle info;
1138   {
1139     objArrayOop info_oop = oopFactory::new_objArray(SystemDictionary::Object_klass(), 2, CHECK_NULL);
1140     info = objArrayHandle(THREAD, info_oop);
1141   }
1142 
1143   info->obj_at_put(0, bsm());
1144 
1145   bool use_BSCI;
1146   switch (UseBootstrapCallInfo) {
1147   default: use_BSCI = true;  break;  // stress mode
1148   case 0:  use_BSCI = false; break;  // stress mode
1149   case 1:                            // normal mode
1150     // If we were to support an alternative mode of BSM invocation,
1151     // we'd convert to pull mode here if the BSM could be a candidate
1152     // for that alternative mode.  We can't easily test for things
1153     // like varargs here, but we can get away with approximate testing,
1154     // since the JDK runtime will make up the difference either way.
1155     // For now, exercise the pull-mode path if the BSM is of arity 2,
1156     // or if there is a potential condy loop (see below).
1157     oop mt_oop = java_lang_invoke_MethodHandle::type(bsm());
1158     use_BSCI = (java_lang_invoke_MethodType::ptype_count(mt_oop) == 2);
1159     break;
1160   }
1161 
1162   // Here's a reason to use BSCI even if it wasn't requested:
1163   // If a condy uses a condy argument, we want to avoid infinite
1164   // recursion (condy loops) in the C code.  It's OK in Java,
1165   // because Java has stack overflow checking, so we punt
1166   // potentially cyclic cases from C to Java.
1167   if (!use_BSCI && this_cp->tag_at(index).is_dynamic_constant()) {
1168     bool found_unresolved_condy = false;
1169     for (int i = 0; i < argc; i++) {
1170       int arg_index = this_cp->invoke_dynamic_argument_index_at(index, i);
1171       if (this_cp->tag_at(arg_index).is_dynamic_constant()) {
1172         // potential recursion point condy -> condy
1173         bool found_it = false;
1174         this_cp->find_cached_constant_at(arg_index, found_it, CHECK_NULL);
1175         if (!found_it) { found_unresolved_condy = true; break; }
1176       }
1177     }
1178     if (found_unresolved_condy)
1179       use_BSCI = true;
1180   }
1181 
1182   const int SMALL_ARITY = 5;
1183   if (use_BSCI && argc <= SMALL_ARITY && UseBootstrapCallInfo <= 2) {
1184     // If there are only a few arguments, and none of them need linking,
1185     // push them, instead of asking the JDK runtime to turn around and
1186     // pull them, saving a JVM/JDK transition in some simple cases.
1187     bool all_resolved = true;
1188     for (int i = 0; i < argc; i++) {
1189       bool found_it = false;
1190       int arg_index = this_cp->invoke_dynamic_argument_index_at(index, i);
1191       this_cp->find_cached_constant_at(arg_index, found_it, CHECK_NULL);
1192       if (!found_it) { all_resolved = false; break; }
1193     }
1194     if (all_resolved)
1195       use_BSCI = false;
1196   }
1197 
1198   if (!use_BSCI) {
1199     // return {bsm, {arg...}}; resolution of arguments is done immediately, before JDK code is called
1200     objArrayOop args_oop = oopFactory::new_objArray(SystemDictionary::Object_klass(), argc, CHECK_NULL);
1201     info->obj_at_put(1, args_oop);   // may overwrite with args[0] below
1202     objArrayHandle args(THREAD, args_oop);
1203     copy_bootstrap_arguments_at_impl(this_cp, index, 0, argc, args, 0, true, Handle(), CHECK_NULL);
1204     if (argc == 1) {
1205       // try to discard the singleton array
1206       oop arg_oop = args->obj_at(0);
1207       if (arg_oop != NULL && !arg_oop->is_array()) {
1208         // JVM treats arrays and nulls specially in this position,
1209         // but other things are just single arguments
1210         info->obj_at_put(1, arg_oop);
1211       }
1212     }
1213   } else {
1214     // return {bsm, {arg_count, pool_index}}; JDK code must pull the arguments as needed
1215     typeArrayOop ints_oop = oopFactory::new_typeArray(T_INT, 2, CHECK_NULL);
1216     ints_oop->int_at_put(0, argc);
1217     ints_oop->int_at_put(1, index);
1218     info->obj_at_put(1, ints_oop);
1219   }
1220   return info();
1221 }
1222 
1223 void ConstantPool::copy_bootstrap_arguments_at_impl(const constantPoolHandle& this_cp, int index,
1224                                                     int start_arg, int end_arg,
1225                                                     objArrayHandle info, int pos,
1226                                                     bool must_resolve, Handle if_not_available,
1227                                                     TRAPS) {
1228   int argc;
1229   int limit = pos + end_arg - start_arg;
1230   // checks: index in range [0..this_cp->length),
1231   // tag at index, start..end in range [0..argc],
1232   // info array non-null, pos..limit in [0..info.length]
1233   if ((0 >= index    || index >= this_cp->length())  ||
1234       !(this_cp->tag_at(index).is_invoke_dynamic()    ||
1235         this_cp->tag_at(index).is_dynamic_constant()) ||
1236       (0 > start_arg || start_arg > end_arg) ||
1237       (end_arg > (argc = this_cp->invoke_dynamic_argument_count_at(index))) ||
1238       (0 > pos       || pos > limit)         ||
1239       (info.is_null() || limit > info->length())) {
1240     // An index or something else went wrong; throw an error.
1241     // Since this is an internal API, we don't expect this,
1242     // so we don't bother to craft a nice message.
1243     THROW_MSG(vmSymbols::java_lang_LinkageError(), "bad BSM argument access");
1244   }
1245   // now we can loop safely
1246   int info_i = pos;
1247   for (int i = start_arg; i < end_arg; i++) {
1248     int arg_index = this_cp->invoke_dynamic_argument_index_at(index, i);
1249     oop arg_oop;
1250     if (must_resolve) {
1251       arg_oop = this_cp->resolve_possibly_cached_constant_at(arg_index, CHECK);
1252     } else {
1253       bool found_it = false;
1254       arg_oop = this_cp->find_cached_constant_at(arg_index, found_it, CHECK);
1255       if (!found_it)  arg_oop = if_not_available();
1256     }
1257     info->obj_at_put(info_i++, arg_oop);
1258   }
1259 }
1260 
1261 oop ConstantPool::string_at_impl(const constantPoolHandle& this_cp, int which, int obj_index, TRAPS) {
1262   // If the string has already been interned, this entry will be non-null
1263   oop str = this_cp->resolved_references()->obj_at(obj_index);
1264   assert(!oopDesc::equals(str, Universe::the_null_sentinel()), "");
1265   if (str != NULL) return str;
1266   Symbol* sym = this_cp->unresolved_string_at(which);
1267   str = StringTable::intern(sym, CHECK_(NULL));
1268   this_cp->string_at_put(which, obj_index, str);
1269   assert(java_lang_String::is_instance(str), "must be string");
1270   return str;
1271 }
1272 
1273 
1274 bool ConstantPool::klass_name_at_matches(const InstanceKlass* k, int which) {
1275   // Names are interned, so we can compare Symbol*s directly
1276   Symbol* cp_name = klass_name_at(which);
1277   return (cp_name == k->name());
1278 }
1279 
1280 
1281 // Iterate over symbols and decrement ones which are Symbol*s
1282 // This is done during GC.
1283 // Only decrement the UTF8 symbols. Strings point to
1284 // these symbols but didn't increment the reference count.
1285 void ConstantPool::unreference_symbols() {
1286   for (int index = 1; index < length(); index++) { // Index 0 is unused
1287     constantTag tag = tag_at(index);
1288     if (tag.is_symbol()) {
1289       symbol_at(index)->decrement_refcount();
1290     }
1291   }
1292 }
1293 
1294 
1295 // Compare this constant pool's entry at index1 to the constant pool
1296 // cp2's entry at index2.
1297 bool ConstantPool::compare_entry_to(int index1, const constantPoolHandle& cp2,
1298        int index2, TRAPS) {
1299 
1300   // The error tags are equivalent to non-error tags when comparing
1301   jbyte t1 = tag_at(index1).non_error_value();
1302   jbyte t2 = cp2->tag_at(index2).non_error_value();
1303 
1304   if (t1 != t2) {
1305     // Not the same entry type so there is nothing else to check. Note
1306     // that this style of checking will consider resolved/unresolved
1307     // class pairs as different.
1308     // From the ConstantPool* API point of view, this is correct
1309     // behavior. See VM_RedefineClasses::merge_constant_pools() to see how this
1310     // plays out in the context of ConstantPool* merging.
1311     return false;
1312   }
1313 
1314   switch (t1) {
1315   case JVM_CONSTANT_Class:
1316   {
1317     Klass* k1 = klass_at(index1, CHECK_false);
1318     Klass* k2 = cp2->klass_at(index2, CHECK_false);
1319     if (k1 == k2) {
1320       return true;
1321     }
1322   } break;
1323 
1324   case JVM_CONSTANT_ClassIndex:
1325   {
1326     int recur1 = klass_index_at(index1);
1327     int recur2 = cp2->klass_index_at(index2);
1328     bool match = compare_entry_to(recur1, cp2, recur2, CHECK_false);
1329     if (match) {
1330       return true;
1331     }
1332   } break;
1333 
1334   case JVM_CONSTANT_Double:
1335   {
1336     jdouble d1 = double_at(index1);
1337     jdouble d2 = cp2->double_at(index2);
1338     if (d1 == d2) {
1339       return true;
1340     }
1341   } break;
1342 
1343   case JVM_CONSTANT_Fieldref:
1344   case JVM_CONSTANT_InterfaceMethodref:
1345   case JVM_CONSTANT_Methodref:
1346   {
1347     int recur1 = uncached_klass_ref_index_at(index1);
1348     int recur2 = cp2->uncached_klass_ref_index_at(index2);
1349     bool match = compare_entry_to(recur1, cp2, recur2, CHECK_false);
1350     if (match) {
1351       recur1 = uncached_name_and_type_ref_index_at(index1);
1352       recur2 = cp2->uncached_name_and_type_ref_index_at(index2);
1353       match = compare_entry_to(recur1, cp2, recur2, CHECK_false);
1354       if (match) {
1355         return true;
1356       }
1357     }
1358   } break;
1359 
1360   case JVM_CONSTANT_Float:
1361   {
1362     jfloat f1 = float_at(index1);
1363     jfloat f2 = cp2->float_at(index2);
1364     if (f1 == f2) {
1365       return true;
1366     }
1367   } break;
1368 
1369   case JVM_CONSTANT_Integer:
1370   {
1371     jint i1 = int_at(index1);
1372     jint i2 = cp2->int_at(index2);
1373     if (i1 == i2) {
1374       return true;
1375     }
1376   } break;
1377 
1378   case JVM_CONSTANT_Long:
1379   {
1380     jlong l1 = long_at(index1);
1381     jlong l2 = cp2->long_at(index2);
1382     if (l1 == l2) {
1383       return true;
1384     }
1385   } break;
1386 
1387   case JVM_CONSTANT_NameAndType:
1388   {
1389     int recur1 = name_ref_index_at(index1);
1390     int recur2 = cp2->name_ref_index_at(index2);
1391     bool match = compare_entry_to(recur1, cp2, recur2, CHECK_false);
1392     if (match) {
1393       recur1 = signature_ref_index_at(index1);
1394       recur2 = cp2->signature_ref_index_at(index2);
1395       match = compare_entry_to(recur1, cp2, recur2, CHECK_false);
1396       if (match) {
1397         return true;
1398       }
1399     }
1400   } break;
1401 
1402   case JVM_CONSTANT_StringIndex:
1403   {
1404     int recur1 = string_index_at(index1);
1405     int recur2 = cp2->string_index_at(index2);
1406     bool match = compare_entry_to(recur1, cp2, recur2, CHECK_false);
1407     if (match) {
1408       return true;
1409     }
1410   } break;
1411 
1412   case JVM_CONSTANT_UnresolvedClass:
1413   {
1414     Symbol* k1 = klass_name_at(index1);
1415     Symbol* k2 = cp2->klass_name_at(index2);
1416     if (k1 == k2) {
1417       return true;
1418     }
1419   } break;
1420 
1421   case JVM_CONSTANT_MethodType:
1422   {
1423     int k1 = method_type_index_at(index1);
1424     int k2 = cp2->method_type_index_at(index2);
1425     bool match = compare_entry_to(k1, cp2, k2, CHECK_false);
1426     if (match) {
1427       return true;
1428     }
1429   } break;
1430 
1431   case JVM_CONSTANT_MethodHandle:
1432   {
1433     int k1 = method_handle_ref_kind_at(index1);
1434     int k2 = cp2->method_handle_ref_kind_at(index2);
1435     if (k1 == k2) {
1436       int i1 = method_handle_index_at(index1);
1437       int i2 = cp2->method_handle_index_at(index2);
1438       bool match = compare_entry_to(i1, cp2, i2, CHECK_false);
1439       if (match) {
1440         return true;
1441       }
1442     }
1443   } break;
1444 
1445   case JVM_CONSTANT_Dynamic:
1446   {
1447     int k1 = invoke_dynamic_name_and_type_ref_index_at(index1);
1448     int k2 = cp2->invoke_dynamic_name_and_type_ref_index_at(index2);
1449     int i1 = invoke_dynamic_bootstrap_specifier_index(index1);
1450     int i2 = cp2->invoke_dynamic_bootstrap_specifier_index(index2);
1451     // separate statements and variables because CHECK_false is used
1452     bool match_entry = compare_entry_to(k1, cp2, k2, CHECK_false);
1453     bool match_operand = compare_operand_to(i1, cp2, i2, CHECK_false);
1454     return (match_entry && match_operand);
1455   } break;
1456 
1457   case JVM_CONSTANT_InvokeDynamic:
1458   {
1459     int k1 = invoke_dynamic_name_and_type_ref_index_at(index1);
1460     int k2 = cp2->invoke_dynamic_name_and_type_ref_index_at(index2);
1461     int i1 = invoke_dynamic_bootstrap_specifier_index(index1);
1462     int i2 = cp2->invoke_dynamic_bootstrap_specifier_index(index2);
1463     // separate statements and variables because CHECK_false is used
1464     bool match_entry = compare_entry_to(k1, cp2, k2, CHECK_false);
1465     bool match_operand = compare_operand_to(i1, cp2, i2, CHECK_false);
1466     return (match_entry && match_operand);
1467   } break;
1468 
1469   case JVM_CONSTANT_String:
1470   {
1471     Symbol* s1 = unresolved_string_at(index1);
1472     Symbol* s2 = cp2->unresolved_string_at(index2);
1473     if (s1 == s2) {
1474       return true;
1475     }
1476   } break;
1477 
1478   case JVM_CONSTANT_Utf8:
1479   {
1480     Symbol* s1 = symbol_at(index1);
1481     Symbol* s2 = cp2->symbol_at(index2);
1482     if (s1 == s2) {
1483       return true;
1484     }
1485   } break;
1486 
1487   // Invalid is used as the tag for the second constant pool entry
1488   // occupied by JVM_CONSTANT_Double or JVM_CONSTANT_Long. It should
1489   // not be seen by itself.
1490   case JVM_CONSTANT_Invalid: // fall through
1491 
1492   default:
1493     ShouldNotReachHere();
1494     break;
1495   }
1496 
1497   return false;
1498 } // end compare_entry_to()
1499 
1500 
1501 // Resize the operands array with delta_len and delta_size.
1502 // Used in RedefineClasses for CP merge.
1503 void ConstantPool::resize_operands(int delta_len, int delta_size, TRAPS) {
1504   int old_len  = operand_array_length(operands());
1505   int new_len  = old_len + delta_len;
1506   int min_len  = (delta_len > 0) ? old_len : new_len;
1507 
1508   int old_size = operands()->length();
1509   int new_size = old_size + delta_size;
1510   int min_size = (delta_size > 0) ? old_size : new_size;
1511 
1512   ClassLoaderData* loader_data = pool_holder()->class_loader_data();
1513   Array<u2>* new_ops = MetadataFactory::new_array<u2>(loader_data, new_size, CHECK);
1514 
1515   // Set index in the resized array for existing elements only
1516   for (int idx = 0; idx < min_len; idx++) {
1517     int offset = operand_offset_at(idx);                       // offset in original array
1518     operand_offset_at_put(new_ops, idx, offset + 2*delta_len); // offset in resized array
1519   }
1520   // Copy the bootstrap specifiers only
1521   Copy::conjoint_memory_atomic(operands()->adr_at(2*old_len),
1522                                new_ops->adr_at(2*new_len),
1523                                (min_size - 2*min_len) * sizeof(u2));
1524   // Explicitly deallocate old operands array.
1525   // Note, it is not needed for 7u backport.
1526   if ( operands() != NULL) { // the safety check
1527     MetadataFactory::free_array<u2>(loader_data, operands());
1528   }
1529   set_operands(new_ops);
1530 } // end resize_operands()
1531 
1532 
1533 // Extend the operands array with the length and size of the ext_cp operands.
1534 // Used in RedefineClasses for CP merge.
1535 void ConstantPool::extend_operands(const constantPoolHandle& ext_cp, TRAPS) {
1536   int delta_len = operand_array_length(ext_cp->operands());
1537   if (delta_len == 0) {
1538     return; // nothing to do
1539   }
1540   int delta_size = ext_cp->operands()->length();
1541 
1542   assert(delta_len  > 0 && delta_size > 0, "extended operands array must be bigger");
1543 
1544   if (operand_array_length(operands()) == 0) {
1545     ClassLoaderData* loader_data = pool_holder()->class_loader_data();
1546     Array<u2>* new_ops = MetadataFactory::new_array<u2>(loader_data, delta_size, CHECK);
1547     // The first element index defines the offset of second part
1548     operand_offset_at_put(new_ops, 0, 2*delta_len); // offset in new array
1549     set_operands(new_ops);
1550   } else {
1551     resize_operands(delta_len, delta_size, CHECK);
1552   }
1553 
1554 } // end extend_operands()
1555 
1556 
1557 // Shrink the operands array to a smaller array with new_len length.
1558 // Used in RedefineClasses for CP merge.
1559 void ConstantPool::shrink_operands(int new_len, TRAPS) {
1560   int old_len = operand_array_length(operands());
1561   if (new_len == old_len) {
1562     return; // nothing to do
1563   }
1564   assert(new_len < old_len, "shrunken operands array must be smaller");
1565 
1566   int free_base  = operand_next_offset_at(new_len - 1);
1567   int delta_len  = new_len - old_len;
1568   int delta_size = 2*delta_len + free_base - operands()->length();
1569 
1570   resize_operands(delta_len, delta_size, CHECK);
1571 
1572 } // end shrink_operands()
1573 
1574 
1575 void ConstantPool::copy_operands(const constantPoolHandle& from_cp,
1576                                  const constantPoolHandle& to_cp,
1577                                  TRAPS) {
1578 
1579   int from_oplen = operand_array_length(from_cp->operands());
1580   int old_oplen  = operand_array_length(to_cp->operands());
1581   if (from_oplen != 0) {
1582     ClassLoaderData* loader_data = to_cp->pool_holder()->class_loader_data();
1583     // append my operands to the target's operands array
1584     if (old_oplen == 0) {
1585       // Can't just reuse from_cp's operand list because of deallocation issues
1586       int len = from_cp->operands()->length();
1587       Array<u2>* new_ops = MetadataFactory::new_array<u2>(loader_data, len, CHECK);
1588       Copy::conjoint_memory_atomic(
1589           from_cp->operands()->adr_at(0), new_ops->adr_at(0), len * sizeof(u2));
1590       to_cp->set_operands(new_ops);
1591     } else {
1592       int old_len  = to_cp->operands()->length();
1593       int from_len = from_cp->operands()->length();
1594       int old_off  = old_oplen * sizeof(u2);
1595       int from_off = from_oplen * sizeof(u2);
1596       // Use the metaspace for the destination constant pool
1597       Array<u2>* new_operands = MetadataFactory::new_array<u2>(loader_data, old_len + from_len, CHECK);
1598       int fillp = 0, len = 0;
1599       // first part of dest
1600       Copy::conjoint_memory_atomic(to_cp->operands()->adr_at(0),
1601                                    new_operands->adr_at(fillp),
1602                                    (len = old_off) * sizeof(u2));
1603       fillp += len;
1604       // first part of src
1605       Copy::conjoint_memory_atomic(from_cp->operands()->adr_at(0),
1606                                    new_operands->adr_at(fillp),
1607                                    (len = from_off) * sizeof(u2));
1608       fillp += len;
1609       // second part of dest
1610       Copy::conjoint_memory_atomic(to_cp->operands()->adr_at(old_off),
1611                                    new_operands->adr_at(fillp),
1612                                    (len = old_len - old_off) * sizeof(u2));
1613       fillp += len;
1614       // second part of src
1615       Copy::conjoint_memory_atomic(from_cp->operands()->adr_at(from_off),
1616                                    new_operands->adr_at(fillp),
1617                                    (len = from_len - from_off) * sizeof(u2));
1618       fillp += len;
1619       assert(fillp == new_operands->length(), "");
1620 
1621       // Adjust indexes in the first part of the copied operands array.
1622       for (int j = 0; j < from_oplen; j++) {
1623         int offset = operand_offset_at(new_operands, old_oplen + j);
1624         assert(offset == operand_offset_at(from_cp->operands(), j), "correct copy");
1625         offset += old_len;  // every new tuple is preceded by old_len extra u2's
1626         operand_offset_at_put(new_operands, old_oplen + j, offset);
1627       }
1628 
1629       // replace target operands array with combined array
1630       to_cp->set_operands(new_operands);
1631     }
1632   }
1633 } // end copy_operands()
1634 
1635 
1636 // Copy this constant pool's entries at start_i to end_i (inclusive)
1637 // to the constant pool to_cp's entries starting at to_i. A total of
1638 // (end_i - start_i) + 1 entries are copied.
1639 void ConstantPool::copy_cp_to_impl(const constantPoolHandle& from_cp, int start_i, int end_i,
1640        const constantPoolHandle& to_cp, int to_i, TRAPS) {
1641 
1642 
1643   int dest_i = to_i;  // leave original alone for debug purposes
1644 
1645   for (int src_i = start_i; src_i <= end_i; /* see loop bottom */ ) {
1646     copy_entry_to(from_cp, src_i, to_cp, dest_i, CHECK);
1647 
1648     switch (from_cp->tag_at(src_i).value()) {
1649     case JVM_CONSTANT_Double:
1650     case JVM_CONSTANT_Long:
1651       // double and long take two constant pool entries
1652       src_i += 2;
1653       dest_i += 2;
1654       break;
1655 
1656     default:
1657       // all others take one constant pool entry
1658       src_i++;
1659       dest_i++;
1660       break;
1661     }
1662   }
1663   copy_operands(from_cp, to_cp, CHECK);
1664 
1665 } // end copy_cp_to_impl()
1666 
1667 
1668 // Copy this constant pool's entry at from_i to the constant pool
1669 // to_cp's entry at to_i.
1670 void ConstantPool::copy_entry_to(const constantPoolHandle& from_cp, int from_i,
1671                                         const constantPoolHandle& to_cp, int to_i,
1672                                         TRAPS) {
1673 
1674   int tag = from_cp->tag_at(from_i).value();
1675   switch (tag) {
1676   case JVM_CONSTANT_ClassIndex:
1677   {
1678     jint ki = from_cp->klass_index_at(from_i);
1679     to_cp->klass_index_at_put(to_i, ki);
1680   } break;
1681 
1682   case JVM_CONSTANT_Double:
1683   {
1684     jdouble d = from_cp->double_at(from_i);
1685     to_cp->double_at_put(to_i, d);
1686     // double takes two constant pool entries so init second entry's tag
1687     to_cp->tag_at_put(to_i + 1, JVM_CONSTANT_Invalid);
1688   } break;
1689 
1690   case JVM_CONSTANT_Fieldref:
1691   {
1692     int class_index = from_cp->uncached_klass_ref_index_at(from_i);
1693     int name_and_type_index = from_cp->uncached_name_and_type_ref_index_at(from_i);
1694     to_cp->field_at_put(to_i, class_index, name_and_type_index);
1695   } break;
1696 
1697   case JVM_CONSTANT_Float:
1698   {
1699     jfloat f = from_cp->float_at(from_i);
1700     to_cp->float_at_put(to_i, f);
1701   } break;
1702 
1703   case JVM_CONSTANT_Integer:
1704   {
1705     jint i = from_cp->int_at(from_i);
1706     to_cp->int_at_put(to_i, i);
1707   } break;
1708 
1709   case JVM_CONSTANT_InterfaceMethodref:
1710   {
1711     int class_index = from_cp->uncached_klass_ref_index_at(from_i);
1712     int name_and_type_index = from_cp->uncached_name_and_type_ref_index_at(from_i);
1713     to_cp->interface_method_at_put(to_i, class_index, name_and_type_index);
1714   } break;
1715 
1716   case JVM_CONSTANT_Long:
1717   {
1718     jlong l = from_cp->long_at(from_i);
1719     to_cp->long_at_put(to_i, l);
1720     // long takes two constant pool entries so init second entry's tag
1721     to_cp->tag_at_put(to_i + 1, JVM_CONSTANT_Invalid);
1722   } break;
1723 
1724   case JVM_CONSTANT_Methodref:
1725   {
1726     int class_index = from_cp->uncached_klass_ref_index_at(from_i);
1727     int name_and_type_index = from_cp->uncached_name_and_type_ref_index_at(from_i);
1728     to_cp->method_at_put(to_i, class_index, name_and_type_index);
1729   } break;
1730 
1731   case JVM_CONSTANT_NameAndType:
1732   {
1733     int name_ref_index = from_cp->name_ref_index_at(from_i);
1734     int signature_ref_index = from_cp->signature_ref_index_at(from_i);
1735     to_cp->name_and_type_at_put(to_i, name_ref_index, signature_ref_index);
1736   } break;
1737 
1738   case JVM_CONSTANT_StringIndex:
1739   {
1740     jint si = from_cp->string_index_at(from_i);
1741     to_cp->string_index_at_put(to_i, si);
1742   } break;
1743 
1744   case JVM_CONSTANT_Class:
1745   case JVM_CONSTANT_UnresolvedClass:
1746   case JVM_CONSTANT_UnresolvedClassInError:
1747   {
1748     // Revert to JVM_CONSTANT_ClassIndex
1749     int name_index = from_cp->klass_slot_at(from_i).name_index();
1750     assert(from_cp->tag_at(name_index).is_symbol(), "sanity");
1751     to_cp->klass_index_at_put(to_i, name_index);
1752   } break;
1753 
1754   case JVM_CONSTANT_String:
1755   {
1756     Symbol* s = from_cp->unresolved_string_at(from_i);
1757     to_cp->unresolved_string_at_put(to_i, s);
1758   } break;
1759 
1760   case JVM_CONSTANT_Utf8:
1761   {
1762     Symbol* s = from_cp->symbol_at(from_i);
1763     // Need to increase refcount, the old one will be thrown away and deferenced
1764     s->increment_refcount();
1765     to_cp->symbol_at_put(to_i, s);
1766   } break;
1767 
1768   case JVM_CONSTANT_MethodType:
1769   case JVM_CONSTANT_MethodTypeInError:
1770   {
1771     jint k = from_cp->method_type_index_at(from_i);
1772     to_cp->method_type_index_at_put(to_i, k);
1773   } break;
1774 
1775   case JVM_CONSTANT_MethodHandle:
1776   case JVM_CONSTANT_MethodHandleInError:
1777   {
1778     int k1 = from_cp->method_handle_ref_kind_at(from_i);
1779     int k2 = from_cp->method_handle_index_at(from_i);
1780     to_cp->method_handle_index_at_put(to_i, k1, k2);
1781   } break;
1782 
1783   case JVM_CONSTANT_Dynamic:
1784   case JVM_CONSTANT_DynamicInError:
1785   {
1786     int k1 = from_cp->invoke_dynamic_bootstrap_specifier_index(from_i);
1787     int k2 = from_cp->invoke_dynamic_name_and_type_ref_index_at(from_i);
1788     k1 += operand_array_length(to_cp->operands());  // to_cp might already have operands
1789     to_cp->dynamic_constant_at_put(to_i, k1, k2);
1790   } break;
1791 
1792   case JVM_CONSTANT_InvokeDynamic:
1793   {
1794     int k1 = from_cp->invoke_dynamic_bootstrap_specifier_index(from_i);
1795     int k2 = from_cp->invoke_dynamic_name_and_type_ref_index_at(from_i);
1796     k1 += operand_array_length(to_cp->operands());  // to_cp might already have operands
1797     to_cp->invoke_dynamic_at_put(to_i, k1, k2);
1798   } break;
1799 
1800   // Invalid is used as the tag for the second constant pool entry
1801   // occupied by JVM_CONSTANT_Double or JVM_CONSTANT_Long. It should
1802   // not be seen by itself.
1803   case JVM_CONSTANT_Invalid: // fall through
1804 
1805   default:
1806   {
1807     ShouldNotReachHere();
1808   } break;
1809   }
1810 } // end copy_entry_to()
1811 
1812 // Search constant pool search_cp for an entry that matches this
1813 // constant pool's entry at pattern_i. Returns the index of a
1814 // matching entry or zero (0) if there is no matching entry.
1815 int ConstantPool::find_matching_entry(int pattern_i,
1816       const constantPoolHandle& search_cp, TRAPS) {
1817 
1818   // index zero (0) is not used
1819   for (int i = 1; i < search_cp->length(); i++) {
1820     bool found = compare_entry_to(pattern_i, search_cp, i, CHECK_0);
1821     if (found) {
1822       return i;
1823     }
1824   }
1825 
1826   return 0;  // entry not found; return unused index zero (0)
1827 } // end find_matching_entry()
1828 
1829 
1830 // Compare this constant pool's bootstrap specifier at idx1 to the constant pool
1831 // cp2's bootstrap specifier at idx2.
1832 bool ConstantPool::compare_operand_to(int idx1, const constantPoolHandle& cp2, int idx2, TRAPS) {
1833   int k1 = operand_bootstrap_method_ref_index_at(idx1);
1834   int k2 = cp2->operand_bootstrap_method_ref_index_at(idx2);
1835   bool match = compare_entry_to(k1, cp2, k2, CHECK_false);
1836 
1837   if (!match) {
1838     return false;
1839   }
1840   int argc = operand_argument_count_at(idx1);
1841   if (argc == cp2->operand_argument_count_at(idx2)) {
1842     for (int j = 0; j < argc; j++) {
1843       k1 = operand_argument_index_at(idx1, j);
1844       k2 = cp2->operand_argument_index_at(idx2, j);
1845       match = compare_entry_to(k1, cp2, k2, CHECK_false);
1846       if (!match) {
1847         return false;
1848       }
1849     }
1850     return true;           // got through loop; all elements equal
1851   }
1852   return false;
1853 } // end compare_operand_to()
1854 
1855 // Search constant pool search_cp for a bootstrap specifier that matches
1856 // this constant pool's bootstrap specifier at pattern_i index.
1857 // Return the index of a matching bootstrap specifier or (-1) if there is no match.
1858 int ConstantPool::find_matching_operand(int pattern_i,
1859                     const constantPoolHandle& search_cp, int search_len, TRAPS) {
1860   for (int i = 0; i < search_len; i++) {
1861     bool found = compare_operand_to(pattern_i, search_cp, i, CHECK_(-1));
1862     if (found) {
1863       return i;
1864     }
1865   }
1866   return -1;  // bootstrap specifier not found; return unused index (-1)
1867 } // end find_matching_operand()
1868 
1869 
1870 #ifndef PRODUCT
1871 
1872 const char* ConstantPool::printable_name_at(int which) {
1873 
1874   constantTag tag = tag_at(which);
1875 
1876   if (tag.is_string()) {
1877     return string_at_noresolve(which);
1878   } else if (tag.is_klass() || tag.is_unresolved_klass()) {
1879     return klass_name_at(which)->as_C_string();
1880   } else if (tag.is_symbol()) {
1881     return symbol_at(which)->as_C_string();
1882   }
1883   return "";
1884 }
1885 
1886 #endif // PRODUCT
1887 
1888 
1889 // JVMTI GetConstantPool support
1890 
1891 // For debugging of constant pool
1892 const bool debug_cpool = false;
1893 
1894 #define DBG(code) do { if (debug_cpool) { (code); } } while(0)
1895 
1896 static void print_cpool_bytes(jint cnt, u1 *bytes) {
1897   const char* WARN_MSG = "Must not be such entry!";
1898   jint size = 0;
1899   u2   idx1, idx2;
1900 
1901   for (jint idx = 1; idx < cnt; idx++) {
1902     jint ent_size = 0;
1903     u1   tag  = *bytes++;
1904     size++;                       // count tag
1905 
1906     printf("const #%03d, tag: %02d ", idx, tag);
1907     switch(tag) {
1908       case JVM_CONSTANT_Invalid: {
1909         printf("Invalid");
1910         break;
1911       }
1912       case JVM_CONSTANT_Unicode: {
1913         printf("Unicode      %s", WARN_MSG);
1914         break;
1915       }
1916       case JVM_CONSTANT_Utf8: {
1917         u2 len = Bytes::get_Java_u2(bytes);
1918         char str[128];
1919         if (len > 127) {
1920            len = 127;
1921         }
1922         strncpy(str, (char *) (bytes+2), len);
1923         str[len] = '\0';
1924         printf("Utf8          \"%s\"", str);
1925         ent_size = 2 + len;
1926         break;
1927       }
1928       case JVM_CONSTANT_Integer: {
1929         u4 val = Bytes::get_Java_u4(bytes);
1930         printf("int          %d", *(int *) &val);
1931         ent_size = 4;
1932         break;
1933       }
1934       case JVM_CONSTANT_Float: {
1935         u4 val = Bytes::get_Java_u4(bytes);
1936         printf("float        %5.3ff", *(float *) &val);
1937         ent_size = 4;
1938         break;
1939       }
1940       case JVM_CONSTANT_Long: {
1941         u8 val = Bytes::get_Java_u8(bytes);
1942         printf("long         " INT64_FORMAT, (int64_t) *(jlong *) &val);
1943         ent_size = 8;
1944         idx++; // Long takes two cpool slots
1945         break;
1946       }
1947       case JVM_CONSTANT_Double: {
1948         u8 val = Bytes::get_Java_u8(bytes);
1949         printf("double       %5.3fd", *(jdouble *)&val);
1950         ent_size = 8;
1951         idx++; // Double takes two cpool slots
1952         break;
1953       }
1954       case JVM_CONSTANT_Class: {
1955         idx1 = Bytes::get_Java_u2(bytes);
1956         printf("class        #%03d", idx1);
1957         ent_size = 2;
1958         break;
1959       }
1960       case JVM_CONSTANT_String: {
1961         idx1 = Bytes::get_Java_u2(bytes);
1962         printf("String       #%03d", idx1);
1963         ent_size = 2;
1964         break;
1965       }
1966       case JVM_CONSTANT_Fieldref: {
1967         idx1 = Bytes::get_Java_u2(bytes);
1968         idx2 = Bytes::get_Java_u2(bytes+2);
1969         printf("Field        #%03d, #%03d", (int) idx1, (int) idx2);
1970         ent_size = 4;
1971         break;
1972       }
1973       case JVM_CONSTANT_Methodref: {
1974         idx1 = Bytes::get_Java_u2(bytes);
1975         idx2 = Bytes::get_Java_u2(bytes+2);
1976         printf("Method       #%03d, #%03d", idx1, idx2);
1977         ent_size = 4;
1978         break;
1979       }
1980       case JVM_CONSTANT_InterfaceMethodref: {
1981         idx1 = Bytes::get_Java_u2(bytes);
1982         idx2 = Bytes::get_Java_u2(bytes+2);
1983         printf("InterfMethod #%03d, #%03d", idx1, idx2);
1984         ent_size = 4;
1985         break;
1986       }
1987       case JVM_CONSTANT_NameAndType: {
1988         idx1 = Bytes::get_Java_u2(bytes);
1989         idx2 = Bytes::get_Java_u2(bytes+2);
1990         printf("NameAndType  #%03d, #%03d", idx1, idx2);
1991         ent_size = 4;
1992         break;
1993       }
1994       case JVM_CONSTANT_ClassIndex: {
1995         printf("ClassIndex  %s", WARN_MSG);
1996         break;
1997       }
1998       case JVM_CONSTANT_UnresolvedClass: {
1999         printf("UnresolvedClass: %s", WARN_MSG);
2000         break;
2001       }
2002       case JVM_CONSTANT_UnresolvedClassInError: {
2003         printf("UnresolvedClassInErr: %s", WARN_MSG);
2004         break;
2005       }
2006       case JVM_CONSTANT_StringIndex: {
2007         printf("StringIndex: %s", WARN_MSG);
2008         break;
2009       }
2010     }
2011     printf(";\n");
2012     bytes += ent_size;
2013     size  += ent_size;
2014   }
2015   printf("Cpool size: %d\n", size);
2016   fflush(0);
2017   return;
2018 } /* end print_cpool_bytes */
2019 
2020 
2021 // Returns size of constant pool entry.
2022 jint ConstantPool::cpool_entry_size(jint idx) {
2023   switch(tag_at(idx).value()) {
2024     case JVM_CONSTANT_Invalid:
2025     case JVM_CONSTANT_Unicode:
2026       return 1;
2027 
2028     case JVM_CONSTANT_Utf8:
2029       return 3 + symbol_at(idx)->utf8_length();
2030 
2031     case JVM_CONSTANT_Class:
2032     case JVM_CONSTANT_String:
2033     case JVM_CONSTANT_ClassIndex:
2034     case JVM_CONSTANT_UnresolvedClass:
2035     case JVM_CONSTANT_UnresolvedClassInError:
2036     case JVM_CONSTANT_StringIndex:
2037     case JVM_CONSTANT_MethodType:
2038     case JVM_CONSTANT_MethodTypeInError:
2039       return 3;
2040 
2041     case JVM_CONSTANT_MethodHandle:
2042     case JVM_CONSTANT_MethodHandleInError:
2043       return 4; //tag, ref_kind, ref_index
2044 
2045     case JVM_CONSTANT_Integer:
2046     case JVM_CONSTANT_Float:
2047     case JVM_CONSTANT_Fieldref:
2048     case JVM_CONSTANT_Methodref:
2049     case JVM_CONSTANT_InterfaceMethodref:
2050     case JVM_CONSTANT_NameAndType:
2051       return 5;
2052 
2053     case JVM_CONSTANT_Dynamic:
2054     case JVM_CONSTANT_DynamicInError:
2055     case JVM_CONSTANT_InvokeDynamic:
2056       // u1 tag, u2 bsm, u2 nt
2057       return 5;
2058 
2059     case JVM_CONSTANT_Long:
2060     case JVM_CONSTANT_Double:
2061       return 9;
2062   }
2063   assert(false, "cpool_entry_size: Invalid constant pool entry tag");
2064   return 1;
2065 } /* end cpool_entry_size */
2066 
2067 
2068 // SymbolHashMap is used to find a constant pool index from a string.
2069 // This function fills in SymbolHashMaps, one for utf8s and one for
2070 // class names, returns size of the cpool raw bytes.
2071 jint ConstantPool::hash_entries_to(SymbolHashMap *symmap,
2072                                           SymbolHashMap *classmap) {
2073   jint size = 0;
2074 
2075   for (u2 idx = 1; idx < length(); idx++) {
2076     u2 tag = tag_at(idx).value();
2077     size += cpool_entry_size(idx);
2078 
2079     switch(tag) {
2080       case JVM_CONSTANT_Utf8: {
2081         Symbol* sym = symbol_at(idx);
2082         symmap->add_entry(sym, idx);
2083         DBG(printf("adding symbol entry %s = %d\n", sym->as_utf8(), idx));
2084         break;
2085       }
2086       case JVM_CONSTANT_Class:
2087       case JVM_CONSTANT_UnresolvedClass:
2088       case JVM_CONSTANT_UnresolvedClassInError: {
2089         Symbol* sym = klass_name_at(idx);
2090         classmap->add_entry(sym, idx);
2091         DBG(printf("adding class entry %s = %d\n", sym->as_utf8(), idx));
2092         break;
2093       }
2094       case JVM_CONSTANT_Long:
2095       case JVM_CONSTANT_Double: {
2096         idx++; // Both Long and Double take two cpool slots
2097         break;
2098       }
2099     }
2100   }
2101   return size;
2102 } /* end hash_utf8_entries_to */
2103 
2104 
2105 // Copy cpool bytes.
2106 // Returns:
2107 //    0, in case of OutOfMemoryError
2108 //   -1, in case of internal error
2109 //  > 0, count of the raw cpool bytes that have been copied
2110 int ConstantPool::copy_cpool_bytes(int cpool_size,
2111                                           SymbolHashMap* tbl,
2112                                           unsigned char *bytes) {
2113   u2   idx1, idx2;
2114   jint size  = 0;
2115   jint cnt   = length();
2116   unsigned char *start_bytes = bytes;
2117 
2118   for (jint idx = 1; idx < cnt; idx++) {
2119     u1   tag      = tag_at(idx).value();
2120     jint ent_size = cpool_entry_size(idx);
2121 
2122     assert(size + ent_size <= cpool_size, "Size mismatch");
2123 
2124     *bytes = tag;
2125     DBG(printf("#%03hd tag=%03hd, ", (short)idx, (short)tag));
2126     switch(tag) {
2127       case JVM_CONSTANT_Invalid: {
2128         DBG(printf("JVM_CONSTANT_Invalid"));
2129         break;
2130       }
2131       case JVM_CONSTANT_Unicode: {
2132         assert(false, "Wrong constant pool tag: JVM_CONSTANT_Unicode");
2133         DBG(printf("JVM_CONSTANT_Unicode"));
2134         break;
2135       }
2136       case JVM_CONSTANT_Utf8: {
2137         Symbol* sym = symbol_at(idx);
2138         char*     str = sym->as_utf8();
2139         // Warning! It's crashing on x86 with len = sym->utf8_length()
2140         int       len = (int) strlen(str);
2141         Bytes::put_Java_u2((address) (bytes+1), (u2) len);
2142         for (int i = 0; i < len; i++) {
2143             bytes[3+i] = (u1) str[i];
2144         }
2145         DBG(printf("JVM_CONSTANT_Utf8: %s ", str));
2146         break;
2147       }
2148       case JVM_CONSTANT_Integer: {
2149         jint val = int_at(idx);
2150         Bytes::put_Java_u4((address) (bytes+1), *(u4*)&val);
2151         break;
2152       }
2153       case JVM_CONSTANT_Float: {
2154         jfloat val = float_at(idx);
2155         Bytes::put_Java_u4((address) (bytes+1), *(u4*)&val);
2156         break;
2157       }
2158       case JVM_CONSTANT_Long: {
2159         jlong val = long_at(idx);
2160         Bytes::put_Java_u8((address) (bytes+1), *(u8*)&val);
2161         idx++;             // Long takes two cpool slots
2162         break;
2163       }
2164       case JVM_CONSTANT_Double: {
2165         jdouble val = double_at(idx);
2166         Bytes::put_Java_u8((address) (bytes+1), *(u8*)&val);
2167         idx++;             // Double takes two cpool slots
2168         break;
2169       }
2170       case JVM_CONSTANT_Class:
2171       case JVM_CONSTANT_UnresolvedClass:
2172       case JVM_CONSTANT_UnresolvedClassInError: {
2173         *bytes = JVM_CONSTANT_Class;
2174         Symbol* sym = klass_name_at(idx);
2175         idx1 = tbl->symbol_to_value(sym);
2176         assert(idx1 != 0, "Have not found a hashtable entry");
2177         Bytes::put_Java_u2((address) (bytes+1), idx1);
2178         DBG(printf("JVM_CONSTANT_Class: idx=#%03hd, %s", idx1, sym->as_utf8()));
2179         break;
2180       }
2181       case JVM_CONSTANT_String: {
2182         *bytes = JVM_CONSTANT_String;
2183         Symbol* sym = unresolved_string_at(idx);
2184         idx1 = tbl->symbol_to_value(sym);
2185         assert(idx1 != 0, "Have not found a hashtable entry");
2186         Bytes::put_Java_u2((address) (bytes+1), idx1);
2187         DBG(printf("JVM_CONSTANT_String: idx=#%03hd, %s", idx1, sym->as_utf8()));
2188         break;
2189       }
2190       case JVM_CONSTANT_Fieldref:
2191       case JVM_CONSTANT_Methodref:
2192       case JVM_CONSTANT_InterfaceMethodref: {
2193         idx1 = uncached_klass_ref_index_at(idx);
2194         idx2 = uncached_name_and_type_ref_index_at(idx);
2195         Bytes::put_Java_u2((address) (bytes+1), idx1);
2196         Bytes::put_Java_u2((address) (bytes+3), idx2);
2197         DBG(printf("JVM_CONSTANT_Methodref: %hd %hd", idx1, idx2));
2198         break;
2199       }
2200       case JVM_CONSTANT_NameAndType: {
2201         idx1 = name_ref_index_at(idx);
2202         idx2 = signature_ref_index_at(idx);
2203         Bytes::put_Java_u2((address) (bytes+1), idx1);
2204         Bytes::put_Java_u2((address) (bytes+3), idx2);
2205         DBG(printf("JVM_CONSTANT_NameAndType: %hd %hd", idx1, idx2));
2206         break;
2207       }
2208       case JVM_CONSTANT_ClassIndex: {
2209         *bytes = JVM_CONSTANT_Class;
2210         idx1 = klass_index_at(idx);
2211         Bytes::put_Java_u2((address) (bytes+1), idx1);
2212         DBG(printf("JVM_CONSTANT_ClassIndex: %hd", idx1));
2213         break;
2214       }
2215       case JVM_CONSTANT_StringIndex: {
2216         *bytes = JVM_CONSTANT_String;
2217         idx1 = string_index_at(idx);
2218         Bytes::put_Java_u2((address) (bytes+1), idx1);
2219         DBG(printf("JVM_CONSTANT_StringIndex: %hd", idx1));
2220         break;
2221       }
2222       case JVM_CONSTANT_MethodHandle:
2223       case JVM_CONSTANT_MethodHandleInError: {
2224         *bytes = JVM_CONSTANT_MethodHandle;
2225         int kind = method_handle_ref_kind_at(idx);
2226         idx1 = method_handle_index_at(idx);
2227         *(bytes+1) = (unsigned char) kind;
2228         Bytes::put_Java_u2((address) (bytes+2), idx1);
2229         DBG(printf("JVM_CONSTANT_MethodHandle: %d %hd", kind, idx1));
2230         break;
2231       }
2232       case JVM_CONSTANT_MethodType:
2233       case JVM_CONSTANT_MethodTypeInError: {
2234         *bytes = JVM_CONSTANT_MethodType;
2235         idx1 = method_type_index_at(idx);
2236         Bytes::put_Java_u2((address) (bytes+1), idx1);
2237         DBG(printf("JVM_CONSTANT_MethodType: %hd", idx1));
2238         break;
2239       }
2240       case JVM_CONSTANT_Dynamic:
2241       case JVM_CONSTANT_DynamicInError: {
2242         *bytes = tag;
2243         idx1 = extract_low_short_from_int(*int_at_addr(idx));
2244         idx2 = extract_high_short_from_int(*int_at_addr(idx));
2245         assert(idx2 == invoke_dynamic_name_and_type_ref_index_at(idx), "correct half of u4");
2246         Bytes::put_Java_u2((address) (bytes+1), idx1);
2247         Bytes::put_Java_u2((address) (bytes+3), idx2);
2248         DBG(printf("JVM_CONSTANT_Dynamic: %hd %hd", idx1, idx2));
2249         break;
2250       }
2251       case JVM_CONSTANT_InvokeDynamic: {
2252         *bytes = tag;
2253         idx1 = extract_low_short_from_int(*int_at_addr(idx));
2254         idx2 = extract_high_short_from_int(*int_at_addr(idx));
2255         assert(idx2 == invoke_dynamic_name_and_type_ref_index_at(idx), "correct half of u4");
2256         Bytes::put_Java_u2((address) (bytes+1), idx1);
2257         Bytes::put_Java_u2((address) (bytes+3), idx2);
2258         DBG(printf("JVM_CONSTANT_InvokeDynamic: %hd %hd", idx1, idx2));
2259         break;
2260       }
2261     }
2262     DBG(printf("\n"));
2263     bytes += ent_size;
2264     size  += ent_size;
2265   }
2266   assert(size == cpool_size, "Size mismatch");
2267 
2268   // Keep temorarily for debugging until it's stable.
2269   DBG(print_cpool_bytes(cnt, start_bytes));
2270   return (int)(bytes - start_bytes);
2271 } /* end copy_cpool_bytes */
2272 
2273 #undef DBG
2274 
2275 
2276 void ConstantPool::set_on_stack(const bool value) {
2277   if (value) {
2278     // Only record if it's not already set.
2279     if (!on_stack()) {
2280       assert(!is_shared(), "should always be set for shared constant pools");
2281       _flags |= _on_stack;
2282       MetadataOnStackMark::record(this);
2283     }
2284   } else {
2285     // Clearing is done single-threadedly.
2286     if (!is_shared()) {
2287       _flags &= ~_on_stack;
2288     }
2289   }
2290 }
2291 
2292 // JSR 292 support for patching constant pool oops after the class is linked and
2293 // the oop array for resolved references are created.
2294 // We can't do this during classfile parsing, which is how the other indexes are
2295 // patched.  The other patches are applied early for some error checking
2296 // so only defer the pseudo_strings.
2297 void ConstantPool::patch_resolved_references(GrowableArray<Handle>* cp_patches) {
2298   for (int index = 1; index < cp_patches->length(); index++) { // Index 0 is unused
2299     Handle patch = cp_patches->at(index);
2300     if (patch.not_null()) {
2301       assert (tag_at(index).is_string(), "should only be string left");
2302       // Patching a string means pre-resolving it.
2303       // The spelling in the constant pool is ignored.
2304       // The constant reference may be any object whatever.
2305       // If it is not a real interned string, the constant is referred
2306       // to as a "pseudo-string", and must be presented to the CP
2307       // explicitly, because it may require scavenging.
2308       int obj_index = cp_to_object_index(index);
2309       pseudo_string_at_put(index, obj_index, patch());
2310      DEBUG_ONLY(cp_patches->at_put(index, Handle());)
2311     }
2312   }
2313 #ifdef ASSERT
2314   // Ensure that all the patches have been used.
2315   for (int index = 0; index < cp_patches->length(); index++) {
2316     assert(cp_patches->at(index).is_null(),
2317            "Unused constant pool patch at %d in class file %s",
2318            index,
2319            pool_holder()->external_name());
2320   }
2321 #endif // ASSERT
2322 }
2323 
2324 #ifndef PRODUCT
2325 
2326 // CompileTheWorld support. Preload all classes loaded references in the passed in constantpool
2327 void ConstantPool::preload_and_initialize_all_classes(ConstantPool* obj, TRAPS) {
2328   guarantee(obj->is_constantPool(), "object must be constant pool");
2329   constantPoolHandle cp(THREAD, (ConstantPool*)obj);
2330   guarantee(cp->pool_holder() != NULL, "must be fully loaded");
2331 
2332   for (int i = 0; i< cp->length();  i++) {
2333     if (cp->tag_at(i).is_unresolved_klass()) {
2334       // This will force loading of the class
2335       Klass* klass = cp->klass_at(i, CHECK);
2336       if (klass->is_instance_klass()) {
2337         // Force initialization of class
2338         InstanceKlass::cast(klass)->initialize(CHECK);
2339       }
2340     }
2341   }
2342 }
2343 
2344 #endif
2345 
2346 
2347 // Printing
2348 
2349 void ConstantPool::print_on(outputStream* st) const {
2350   assert(is_constantPool(), "must be constantPool");
2351   st->print_cr("%s", internal_name());
2352   if (flags() != 0) {
2353     st->print(" - flags: 0x%x", flags());
2354     if (has_preresolution()) st->print(" has_preresolution");
2355     if (on_stack()) st->print(" on_stack");
2356     st->cr();
2357   }
2358   if (pool_holder() != NULL) {
2359     st->print_cr(" - holder: " INTPTR_FORMAT, p2i(pool_holder()));
2360   }
2361   st->print_cr(" - cache: " INTPTR_FORMAT, p2i(cache()));
2362   st->print_cr(" - resolved_references: " INTPTR_FORMAT, p2i(resolved_references()));
2363   st->print_cr(" - reference_map: " INTPTR_FORMAT, p2i(reference_map()));
2364   st->print_cr(" - resolved_klasses: " INTPTR_FORMAT, p2i(resolved_klasses()));
2365 
2366   for (int index = 1; index < length(); index++) {      // Index 0 is unused
2367     ((ConstantPool*)this)->print_entry_on(index, st);
2368     switch (tag_at(index).value()) {
2369       case JVM_CONSTANT_Long :
2370       case JVM_CONSTANT_Double :
2371         index++;   // Skip entry following eigth-byte constant
2372     }
2373 
2374   }
2375   st->cr();
2376 }
2377 
2378 // Print one constant pool entry
2379 void ConstantPool::print_entry_on(const int index, outputStream* st) {
2380   EXCEPTION_MARK;
2381   st->print(" - %3d : ", index);
2382   tag_at(index).print_on(st);
2383   st->print(" : ");
2384   switch (tag_at(index).value()) {
2385     case JVM_CONSTANT_Class :
2386       { Klass* k = klass_at(index, CATCH);
2387         guarantee(k != NULL, "need klass");
2388         k->print_value_on(st);
2389         st->print(" {" PTR_FORMAT "}", p2i(k));
2390       }
2391       break;
2392     case JVM_CONSTANT_Fieldref :
2393     case JVM_CONSTANT_Methodref :
2394     case JVM_CONSTANT_InterfaceMethodref :
2395       st->print("klass_index=%d", uncached_klass_ref_index_at(index));
2396       st->print(" name_and_type_index=%d", uncached_name_and_type_ref_index_at(index));
2397       break;
2398     case JVM_CONSTANT_String :
2399       if (is_pseudo_string_at(index)) {
2400         oop anObj = pseudo_string_at(index);
2401         anObj->print_value_on(st);
2402         st->print(" {" PTR_FORMAT "}", p2i(anObj));
2403       } else {
2404         unresolved_string_at(index)->print_value_on(st);
2405       }
2406       break;
2407     case JVM_CONSTANT_Integer :
2408       st->print("%d", int_at(index));
2409       break;
2410     case JVM_CONSTANT_Float :
2411       st->print("%f", float_at(index));
2412       break;
2413     case JVM_CONSTANT_Long :
2414       st->print_jlong(long_at(index));
2415       break;
2416     case JVM_CONSTANT_Double :
2417       st->print("%lf", double_at(index));
2418       break;
2419     case JVM_CONSTANT_NameAndType :
2420       st->print("name_index=%d", name_ref_index_at(index));
2421       st->print(" signature_index=%d", signature_ref_index_at(index));
2422       break;
2423     case JVM_CONSTANT_Utf8 :
2424       symbol_at(index)->print_value_on(st);
2425       break;
2426     case JVM_CONSTANT_ClassIndex: {
2427         int name_index = *int_at_addr(index);
2428         st->print("klass_index=%d ", name_index);
2429         symbol_at(name_index)->print_value_on(st);
2430       }
2431       break;
2432     case JVM_CONSTANT_UnresolvedClass :               // fall-through
2433     case JVM_CONSTANT_UnresolvedClassInError: {
2434         CPKlassSlot kslot = klass_slot_at(index);
2435         int resolved_klass_index = kslot.resolved_klass_index();
2436         int name_index = kslot.name_index();
2437         assert(tag_at(name_index).is_symbol(), "sanity");
2438 
2439         Klass* klass = resolved_klasses()->at(resolved_klass_index);
2440         if (klass != NULL) {
2441           klass->print_value_on(st);
2442         } else {
2443           symbol_at(name_index)->print_value_on(st);
2444         }
2445       }
2446       break;
2447     case JVM_CONSTANT_MethodHandle :
2448     case JVM_CONSTANT_MethodHandleInError :
2449       st->print("ref_kind=%d", method_handle_ref_kind_at(index));
2450       st->print(" ref_index=%d", method_handle_index_at(index));
2451       break;
2452     case JVM_CONSTANT_MethodType :
2453     case JVM_CONSTANT_MethodTypeInError :
2454       st->print("signature_index=%d", method_type_index_at(index));
2455       break;
2456     case JVM_CONSTANT_Dynamic :
2457     case JVM_CONSTANT_DynamicInError :
2458       {
2459         st->print("bootstrap_method_index=%d", invoke_dynamic_bootstrap_method_ref_index_at(index));
2460         st->print(" type_index=%d", invoke_dynamic_name_and_type_ref_index_at(index));
2461         int argc = invoke_dynamic_argument_count_at(index);
2462         if (argc > 0) {
2463           for (int arg_i = 0; arg_i < argc; arg_i++) {
2464             int arg = invoke_dynamic_argument_index_at(index, arg_i);
2465             st->print((arg_i == 0 ? " arguments={%d" : ", %d"), arg);
2466           }
2467           st->print("}");
2468         }
2469       }
2470       break;
2471     case JVM_CONSTANT_InvokeDynamic :
2472       {
2473         st->print("bootstrap_method_index=%d", invoke_dynamic_bootstrap_method_ref_index_at(index));
2474         st->print(" name_and_type_index=%d", invoke_dynamic_name_and_type_ref_index_at(index));
2475         int argc = invoke_dynamic_argument_count_at(index);
2476         if (argc > 0) {
2477           for (int arg_i = 0; arg_i < argc; arg_i++) {
2478             int arg = invoke_dynamic_argument_index_at(index, arg_i);
2479             st->print((arg_i == 0 ? " arguments={%d" : ", %d"), arg);
2480           }
2481           st->print("}");
2482         }
2483       }
2484       break;
2485     default:
2486       ShouldNotReachHere();
2487       break;
2488   }
2489   st->cr();
2490 }
2491 
2492 void ConstantPool::print_value_on(outputStream* st) const {
2493   assert(is_constantPool(), "must be constantPool");
2494   st->print("constant pool [%d]", length());
2495   if (has_preresolution()) st->print("/preresolution");
2496   if (operands() != NULL)  st->print("/operands[%d]", operands()->length());
2497   print_address_on(st);
2498   if (pool_holder() != NULL) {
2499     st->print(" for ");
2500     pool_holder()->print_value_on(st);
2501     bool extra = (pool_holder()->constants() != this);
2502     if (extra)  st->print(" (extra)");
2503   }
2504   if (cache() != NULL) {
2505     st->print(" cache=" PTR_FORMAT, p2i(cache()));
2506   }
2507 }
2508 
2509 #if INCLUDE_SERVICES
2510 // Size Statistics
2511 void ConstantPool::collect_statistics(KlassSizeStats *sz) const {
2512   sz->_cp_all_bytes += (sz->_cp_bytes          = sz->count(this));
2513   sz->_cp_all_bytes += (sz->_cp_tags_bytes     = sz->count_array(tags()));
2514   sz->_cp_all_bytes += (sz->_cp_cache_bytes    = sz->count(cache()));
2515   sz->_cp_all_bytes += (sz->_cp_operands_bytes = sz->count_array(operands()));
2516   sz->_cp_all_bytes += (sz->_cp_refmap_bytes   = sz->count_array(reference_map()));
2517 
2518   sz->_ro_bytes += sz->_cp_operands_bytes + sz->_cp_tags_bytes +
2519                    sz->_cp_refmap_bytes;
2520   sz->_rw_bytes += sz->_cp_bytes + sz->_cp_cache_bytes;
2521 }
2522 #endif // INCLUDE_SERVICES
2523 
2524 // Verification
2525 
2526 void ConstantPool::verify_on(outputStream* st) {
2527   guarantee(is_constantPool(), "object must be constant pool");
2528   for (int i = 0; i< length();  i++) {
2529     constantTag tag = tag_at(i);
2530     if (tag.is_klass() || tag.is_unresolved_klass()) {
2531       guarantee(klass_name_at(i)->refcount() != 0, "should have nonzero reference count");
2532     } else if (tag.is_symbol()) {
2533       CPSlot entry = slot_at(i);
2534       guarantee(entry.get_symbol()->refcount() != 0, "should have nonzero reference count");
2535     } else if (tag.is_string()) {
2536       CPSlot entry = slot_at(i);
2537       guarantee(entry.get_symbol()->refcount() != 0, "should have nonzero reference count");
2538     }
2539   }
2540   if (cache() != NULL) {
2541     // Note: cache() can be NULL before a class is completely setup or
2542     // in temporary constant pools used during constant pool merging
2543     guarantee(cache()->is_constantPoolCache(), "should be constant pool cache");
2544   }
2545   if (pool_holder() != NULL) {
2546     // Note: pool_holder() can be NULL in temporary constant pools
2547     // used during constant pool merging
2548     guarantee(pool_holder()->is_klass(),    "should be klass");
2549   }
2550 }
2551 
2552 
2553 SymbolHashMap::~SymbolHashMap() {
2554   SymbolHashMapEntry* next;
2555   for (int i = 0; i < _table_size; i++) {
2556     for (SymbolHashMapEntry* cur = bucket(i); cur != NULL; cur = next) {
2557       next = cur->next();
2558       delete(cur);
2559     }
2560   }
2561   FREE_C_HEAP_ARRAY(SymbolHashMapBucket, _buckets);
2562 }
2563 
2564 void SymbolHashMap::add_entry(Symbol* sym, u2 value) {
2565   char *str = sym->as_utf8();
2566   unsigned int hash = compute_hash(str, sym->utf8_length());
2567   unsigned int index = hash % table_size();
2568 
2569   // check if already in map
2570   // we prefer the first entry since it is more likely to be what was used in
2571   // the class file
2572   for (SymbolHashMapEntry *en = bucket(index); en != NULL; en = en->next()) {
2573     assert(en->symbol() != NULL, "SymbolHashMapEntry symbol is NULL");
2574     if (en->hash() == hash && en->symbol() == sym) {
2575         return;  // already there
2576     }
2577   }
2578 
2579   SymbolHashMapEntry* entry = new SymbolHashMapEntry(hash, sym, value);
2580   entry->set_next(bucket(index));
2581   _buckets[index].set_entry(entry);
2582   assert(entry->symbol() != NULL, "SymbolHashMapEntry symbol is NULL");
2583 }
2584 
2585 SymbolHashMapEntry* SymbolHashMap::find_entry(Symbol* sym) {
2586   assert(sym != NULL, "SymbolHashMap::find_entry - symbol is NULL");
2587   char *str = sym->as_utf8();
2588   int   len = sym->utf8_length();
2589   unsigned int hash = SymbolHashMap::compute_hash(str, len);
2590   unsigned int index = hash % table_size();
2591   for (SymbolHashMapEntry *en = bucket(index); en != NULL; en = en->next()) {
2592     assert(en->symbol() != NULL, "SymbolHashMapEntry symbol is NULL");
2593     if (en->hash() == hash && en->symbol() == sym) {
2594       return en;
2595     }
2596   }
2597   return NULL;
2598 }
2599 
2600 void SymbolHashMap::initialize_table(int table_size) {
2601   _table_size = table_size;
2602   _buckets = NEW_C_HEAP_ARRAY(SymbolHashMapBucket, table_size, mtSymbol);
2603   for (int index = 0; index < table_size; index++) {
2604     _buckets[index].clear();
2605   }
2606 }