1 /*
   2  * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "classfile/classLoaderData.hpp"
  27 #include "classfile/javaClasses.hpp"
  28 #include "classfile/metadataOnStackMark.hpp"
  29 #include "classfile/stringTable.hpp"
  30 #include "classfile/systemDictionary.hpp"
  31 #include "classfile/vmSymbols.hpp"
  32 #include "interpreter/linkResolver.hpp"
  33 #include "memory/heapInspection.hpp"
  34 #include "memory/metadataFactory.hpp"
  35 #include "memory/oopFactory.hpp"
  36 #include "oops/constantPool.hpp"
  37 #include "oops/instanceKlass.hpp"
  38 #include "oops/objArrayKlass.hpp"
  39 #include "runtime/fieldType.hpp"
  40 #include "runtime/init.hpp"
  41 #include "runtime/javaCalls.hpp"
  42 #include "runtime/signature.hpp"
  43 #include "runtime/vframe.hpp"
  44 
  45 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
  46 
  47 ConstantPool* ConstantPool::allocate(ClassLoaderData* loader_data, int length, TRAPS) {
  48   // Tags are RW but comment below applies to tags also.
  49   Array<u1>* tags = MetadataFactory::new_writeable_array<u1>(loader_data, length, 0, CHECK_NULL);
  50 
  51   int size = ConstantPool::size(length);
  52 
  53   // CDS considerations:
  54   // Allocate read-write but may be able to move to read-only at dumping time
  55   // if all the klasses are resolved.  The only other field that is writable is
  56   // the resolved_references array, which is recreated at startup time.
  57   // But that could be moved to InstanceKlass (although a pain to access from
  58   // assembly code).  Maybe it could be moved to the cpCache which is RW.
  59   return new (loader_data, size, false, MetaspaceObj::ConstantPoolType, THREAD) ConstantPool(tags);
  60 }
  61 
  62 ConstantPool::ConstantPool(Array<u1>* tags) {
  63   set_length(tags->length());
  64   set_tags(NULL);
  65   set_cache(NULL);
  66   set_reference_map(NULL);
  67   set_resolved_references(NULL);
  68   set_operands(NULL);
  69   set_pool_holder(NULL);
  70   set_flags(0);
  71 
  72   // only set to non-zero if constant pool is merged by RedefineClasses
  73   set_version(0);
  74 
  75   // initialize tag array
  76   int length = tags->length();
  77   for (int index = 0; index < length; index++) {
  78     tags->at_put(index, JVM_CONSTANT_Invalid);
  79   }
  80   set_tags(tags);
  81 }
  82 
  83 void ConstantPool::deallocate_contents(ClassLoaderData* loader_data) {
  84   MetadataFactory::free_metadata(loader_data, cache());
  85   set_cache(NULL);
  86   MetadataFactory::free_array<u2>(loader_data, reference_map());
  87   set_reference_map(NULL);
  88 
  89   MetadataFactory::free_array<jushort>(loader_data, operands());
  90   set_operands(NULL);
  91 
  92   release_C_heap_structures();
  93 
  94   // free tag array
  95   MetadataFactory::free_array<u1>(loader_data, tags());
  96   set_tags(NULL);
  97 }
  98 
  99 void ConstantPool::release_C_heap_structures() {
 100   // walk constant pool and decrement symbol reference counts
 101   unreference_symbols();
 102 }
 103 
 104 objArrayOop ConstantPool::resolved_references() const {
 105   return (objArrayOop)JNIHandles::resolve(_resolved_references);
 106 }
 107 
 108 // Create resolved_references array and mapping array for original cp indexes
 109 // The ldc bytecode was rewritten to have the resolved reference array index so need a way
 110 // to map it back for resolving and some unlikely miscellaneous uses.
 111 // The objects created by invokedynamic are appended to this list.
 112 void ConstantPool::initialize_resolved_references(ClassLoaderData* loader_data,
 113                                                   intStack reference_map,
 114                                                   int constant_pool_map_length,
 115                                                   TRAPS) {
 116   // Initialized the resolved object cache.
 117   int map_length = reference_map.length();
 118   if (map_length > 0) {
 119     // Only need mapping back to constant pool entries.  The map isn't used for
 120     // invokedynamic resolved_reference entries.  For invokedynamic entries,
 121     // the constant pool cache index has the mapping back to both the constant
 122     // pool and to the resolved reference index.
 123     if (constant_pool_map_length > 0) {
 124       Array<u2>* om = MetadataFactory::new_array<u2>(loader_data, constant_pool_map_length, CHECK);
 125 
 126       for (int i = 0; i < constant_pool_map_length; i++) {
 127         int x = reference_map.at(i);
 128         assert(x == (int)(jushort) x, "klass index is too big");
 129         om->at_put(i, (jushort)x);
 130       }
 131       set_reference_map(om);
 132     }
 133 
 134     // Create Java array for holding resolved strings, methodHandles,
 135     // methodTypes, invokedynamic and invokehandle appendix objects, etc.
 136     objArrayOop stom = oopFactory::new_objArray(SystemDictionary::Object_klass(), map_length, CHECK);
 137     Handle refs_handle (THREAD, (oop)stom);  // must handleize.
 138     set_resolved_references(loader_data->add_handle(refs_handle));
 139   }
 140 }
 141 
 142 // CDS support. Create a new resolved_references array.
 143 void ConstantPool::restore_unshareable_info(TRAPS) {
 144 
 145   // Only create the new resolved references array if it hasn't been attempted before
 146   if (resolved_references() != NULL) return;
 147 
 148   // restore the C++ vtable from the shared archive
 149   restore_vtable();
 150 
 151   if (SystemDictionary::Object_klass_loaded()) {
 152     // Recreate the object array and add to ClassLoaderData.
 153     int map_length = resolved_reference_length();
 154     if (map_length > 0) {
 155       objArrayOop stom = oopFactory::new_objArray(SystemDictionary::Object_klass(), map_length, CHECK);
 156       Handle refs_handle (THREAD, (oop)stom);  // must handleize.
 157 
 158       ClassLoaderData* loader_data = pool_holder()->class_loader_data();
 159       set_resolved_references(loader_data->add_handle(refs_handle));
 160     }
 161   }
 162 }
 163 
 164 void ConstantPool::remove_unshareable_info() {
 165   // Resolved references are not in the shared archive.
 166   // Save the length for restoration.  It is not necessarily the same length
 167   // as reference_map.length() if invokedynamic is saved.
 168   set_resolved_reference_length(
 169     resolved_references() != NULL ? resolved_references()->length() : 0);
 170   set_resolved_references(NULL);
 171 }
 172 
 173 int ConstantPool::cp_to_object_index(int cp_index) {
 174   // this is harder don't do this so much.
 175   int i = reference_map()->find(cp_index);
 176   // We might not find the index for jsr292 call.
 177   return (i < 0) ? _no_index_sentinel : i;
 178 }
 179 
 180 void ConstantPool::trace_class_resolution(constantPoolHandle this_cp, KlassHandle k) {
 181   ResourceMark rm;
 182   int line_number = -1;
 183   const char * source_file = NULL;
 184   if (JavaThread::current()->has_last_Java_frame()) {
 185     // try to identify the method which called this function.
 186     vframeStream vfst(JavaThread::current());
 187     if (!vfst.at_end()) {
 188       line_number = vfst.method()->line_number_from_bci(vfst.bci());
 189       Symbol* s = vfst.method()->method_holder()->source_file_name();
 190       if (s != NULL) {
 191         source_file = s->as_C_string();
 192       }
 193     }
 194   }
 195   if (k() != this_cp->pool_holder()) {
 196     // only print something if the classes are different
 197     if (source_file != NULL) {
 198       tty->print("RESOLVE %s %s %s:%d\n",
 199                  this_cp->pool_holder()->external_name(),
 200                  InstanceKlass::cast(k())->external_name(), source_file, line_number);
 201     } else {
 202       tty->print("RESOLVE %s %s\n",
 203                  this_cp->pool_holder()->external_name(),
 204                  InstanceKlass::cast(k())->external_name());
 205     }
 206   }
 207 }
 208 
 209 Klass* ConstantPool::klass_at_impl(constantPoolHandle this_cp, int which,
 210                                    bool save_resolution_error, TRAPS) {
 211   assert(THREAD->is_Java_thread(), "must be a Java thread");
 212 
 213   // A resolved constantPool entry will contain a Klass*, otherwise a Symbol*.
 214   // It is not safe to rely on the tag bit's here, since we don't have a lock, and
 215   // the entry and tag is not updated atomicly.
 216   CPSlot entry = this_cp->slot_at(which);
 217   if (entry.is_resolved()) {
 218     assert(entry.get_klass()->is_klass(), "must be");
 219     // Already resolved - return entry.
 220     return entry.get_klass();
 221   }
 222 
 223   // This tag doesn't change back to unresolved class unless at a safepoint.
 224   if (this_cp->tag_at(which).is_unresolved_klass_in_error()) {
 225     // The original attempt to resolve this constant pool entry failed so find the
 226     // class of the original error and throw another error of the same class
 227     // (JVMS 5.4.3).
 228     // If there is a detail message, pass that detail message to the error.
 229     // The JVMS does not strictly require us to duplicate the same detail message,
 230     // or any internal exception fields such as cause or stacktrace.  But since the
 231     // detail message is often a class name or other literal string, we will repeat it
 232     // if we can find it in the symbol table.
 233     throw_resolution_error(this_cp, which, CHECK_0);
 234     ShouldNotReachHere();
 235   }
 236 
 237   Handle mirror_handle;
 238   Symbol* name = entry.get_symbol();
 239   Handle loader (THREAD, this_cp->pool_holder()->class_loader());
 240   Handle protection_domain (THREAD, this_cp->pool_holder()->protection_domain());
 241   Klass* kk = SystemDictionary::resolve_or_fail(name, loader, protection_domain, true, THREAD);
 242   KlassHandle k (THREAD, kk);
 243   if (!HAS_PENDING_EXCEPTION) {
 244     // preserve the resolved klass from unloading
 245     mirror_handle = Handle(THREAD, kk->java_mirror());
 246     // Do access check for klasses
 247     verify_constant_pool_resolve(this_cp, k, THREAD);
 248   }
 249 
 250   // Failed to resolve class. We must record the errors so that subsequent attempts
 251   // to resolve this constant pool entry fail with the same error (JVMS 5.4.3).
 252   if (HAS_PENDING_EXCEPTION) {
 253     if (save_resolution_error) {
 254       save_and_throw_exception(this_cp, which, constantTag(JVM_CONSTANT_UnresolvedClass), CHECK_NULL);
 255       // If CHECK_NULL above doesn't return the exception, that means that
 256       // some other thread has beaten us and has resolved the class.
 257       // To preserve old behavior, we return the resolved class.
 258       entry = this_cp->resolved_klass_at(which);
 259       assert(entry.is_resolved(), "must be resolved if exception was cleared");
 260       assert(entry.get_klass()->is_klass(), "must be resolved to a klass");
 261       return entry.get_klass();
 262     } else {
 263       return NULL;  // return the pending exception
 264     }
 265   }
 266 
 267   // Make this class loader depend upon the class loader owning the class reference
 268   ClassLoaderData* this_key = this_cp->pool_holder()->class_loader_data();
 269   this_key->record_dependency(k(), CHECK_NULL); // Can throw OOM
 270 
 271   if (TraceClassResolution && !k->oop_is_array()) {
 272     // skip resolving the constant pool so that this code gets
 273     // called the next time some bytecodes refer to this class.
 274     trace_class_resolution(this_cp, k);
 275     return k();
 276   } else {
 277     this_cp->klass_at_put(which, k());
 278   }
 279 
 280   entry = this_cp->resolved_klass_at(which);
 281   assert(entry.is_resolved() && entry.get_klass()->is_klass(), "must be resolved at this point");
 282   return entry.get_klass();
 283 }
 284 
 285 
 286 // Does not update ConstantPool* - to avoid any exception throwing. Used
 287 // by compiler and exception handling.  Also used to avoid classloads for
 288 // instanceof operations. Returns NULL if the class has not been loaded or
 289 // if the verification of constant pool failed
 290 Klass* ConstantPool::klass_at_if_loaded(constantPoolHandle this_cp, int which) {
 291   CPSlot entry = this_cp->slot_at(which);
 292   if (entry.is_resolved()) {
 293     assert(entry.get_klass()->is_klass(), "must be");
 294     return entry.get_klass();
 295   } else {
 296     assert(entry.is_unresolved(), "must be either symbol or klass");
 297     Thread *thread = Thread::current();
 298     Symbol* name = entry.get_symbol();
 299     oop loader = this_cp->pool_holder()->class_loader();
 300     oop protection_domain = this_cp->pool_holder()->protection_domain();
 301     Handle h_prot (thread, protection_domain);
 302     Handle h_loader (thread, loader);
 303     Klass* k = SystemDictionary::find(name, h_loader, h_prot, thread);
 304 
 305     if (k != NULL) {
 306       // Make sure that resolving is legal
 307       EXCEPTION_MARK;
 308       KlassHandle klass(THREAD, k);
 309       // return NULL if verification fails
 310       verify_constant_pool_resolve(this_cp, klass, THREAD);
 311       if (HAS_PENDING_EXCEPTION) {
 312         CLEAR_PENDING_EXCEPTION;
 313         return NULL;
 314       }
 315       return klass();
 316     } else {
 317       return k;
 318     }
 319   }
 320 }
 321 
 322 
 323 Klass* ConstantPool::klass_ref_at_if_loaded(constantPoolHandle this_cp, int which) {
 324   return klass_at_if_loaded(this_cp, this_cp->klass_ref_index_at(which));
 325 }
 326 
 327 
 328 Method* ConstantPool::method_at_if_loaded(constantPoolHandle cpool,
 329                                                    int which) {
 330   if (cpool->cache() == NULL)  return NULL;  // nothing to load yet
 331   int cache_index = decode_cpcache_index(which, true);
 332   if (!(cache_index >= 0 && cache_index < cpool->cache()->length())) {
 333     // FIXME: should be an assert
 334     if (PrintMiscellaneous && (Verbose||WizardMode)) {
 335       tty->print_cr("bad operand %d in:", which); cpool->print();
 336     }
 337     return NULL;
 338   }
 339   ConstantPoolCacheEntry* e = cpool->cache()->entry_at(cache_index);
 340   return e->method_if_resolved(cpool);
 341 }
 342 
 343 
 344 bool ConstantPool::has_appendix_at_if_loaded(constantPoolHandle cpool, int which) {
 345   if (cpool->cache() == NULL)  return false;  // nothing to load yet
 346   int cache_index = decode_cpcache_index(which, true);
 347   ConstantPoolCacheEntry* e = cpool->cache()->entry_at(cache_index);
 348   return e->has_appendix();
 349 }
 350 
 351 oop ConstantPool::appendix_at_if_loaded(constantPoolHandle cpool, int which) {
 352   if (cpool->cache() == NULL)  return NULL;  // nothing to load yet
 353   int cache_index = decode_cpcache_index(which, true);
 354   ConstantPoolCacheEntry* e = cpool->cache()->entry_at(cache_index);
 355   return e->appendix_if_resolved(cpool);
 356 }
 357 
 358 
 359 bool ConstantPool::has_method_type_at_if_loaded(constantPoolHandle cpool, int which) {
 360   if (cpool->cache() == NULL)  return false;  // nothing to load yet
 361   int cache_index = decode_cpcache_index(which, true);
 362   ConstantPoolCacheEntry* e = cpool->cache()->entry_at(cache_index);
 363   return e->has_method_type();
 364 }
 365 
 366 oop ConstantPool::method_type_at_if_loaded(constantPoolHandle cpool, int which) {
 367   if (cpool->cache() == NULL)  return NULL;  // nothing to load yet
 368   int cache_index = decode_cpcache_index(which, true);
 369   ConstantPoolCacheEntry* e = cpool->cache()->entry_at(cache_index);
 370   return e->method_type_if_resolved(cpool);
 371 }
 372 
 373 
 374 Symbol* ConstantPool::impl_name_ref_at(int which, bool uncached) {
 375   int name_index = name_ref_index_at(impl_name_and_type_ref_index_at(which, uncached));
 376   return symbol_at(name_index);
 377 }
 378 
 379 
 380 Symbol* ConstantPool::impl_signature_ref_at(int which, bool uncached) {
 381   int signature_index = signature_ref_index_at(impl_name_and_type_ref_index_at(which, uncached));
 382   return symbol_at(signature_index);
 383 }
 384 
 385 
 386 int ConstantPool::impl_name_and_type_ref_index_at(int which, bool uncached) {
 387   int i = which;
 388   if (!uncached && cache() != NULL) {
 389     if (ConstantPool::is_invokedynamic_index(which)) {
 390       // Invokedynamic index is index into resolved_references
 391       int pool_index = invokedynamic_cp_cache_entry_at(which)->constant_pool_index();
 392       pool_index = invoke_dynamic_name_and_type_ref_index_at(pool_index);
 393       assert(tag_at(pool_index).is_name_and_type(), "");
 394       return pool_index;
 395     }
 396     // change byte-ordering and go via cache
 397     i = remap_instruction_operand_from_cache(which);
 398   } else {
 399     if (tag_at(which).is_invoke_dynamic()) {
 400       int pool_index = invoke_dynamic_name_and_type_ref_index_at(which);
 401       assert(tag_at(pool_index).is_name_and_type(), "");
 402       return pool_index;
 403     }
 404   }
 405   assert(tag_at(i).is_field_or_method(), "Corrupted constant pool");
 406   assert(!tag_at(i).is_invoke_dynamic(), "Must be handled above");
 407   jint ref_index = *int_at_addr(i);
 408   return extract_high_short_from_int(ref_index);
 409 }
 410 
 411 
 412 int ConstantPool::impl_klass_ref_index_at(int which, bool uncached) {
 413   guarantee(!ConstantPool::is_invokedynamic_index(which),
 414             "an invokedynamic instruction does not have a klass");
 415   int i = which;
 416   if (!uncached && cache() != NULL) {
 417     // change byte-ordering and go via cache
 418     i = remap_instruction_operand_from_cache(which);
 419   }
 420   assert(tag_at(i).is_field_or_method(), "Corrupted constant pool");
 421   jint ref_index = *int_at_addr(i);
 422   return extract_low_short_from_int(ref_index);
 423 }
 424 
 425 
 426 
 427 int ConstantPool::remap_instruction_operand_from_cache(int operand) {
 428   int cpc_index = operand;
 429   DEBUG_ONLY(cpc_index -= CPCACHE_INDEX_TAG);
 430   assert((int)(u2)cpc_index == cpc_index, "clean u2");
 431   int member_index = cache()->entry_at(cpc_index)->constant_pool_index();
 432   return member_index;
 433 }
 434 
 435 
 436 void ConstantPool::verify_constant_pool_resolve(constantPoolHandle this_cp, KlassHandle k, TRAPS) {
 437  if (k->oop_is_instance() || k->oop_is_objArray()) {
 438     instanceKlassHandle holder (THREAD, this_cp->pool_holder());
 439     Klass* elem = k->oop_is_instance() ? k() : ObjArrayKlass::cast(k())->bottom_klass();
 440     KlassHandle element (THREAD, elem);
 441 
 442     // The element type could be a typeArray - we only need the access check if it is
 443     // an reference to another class
 444     if (element->oop_is_instance()) {
 445       LinkResolver::check_klass_accessability(holder, element, CHECK);
 446     }
 447   }
 448 }
 449 
 450 
 451 int ConstantPool::name_ref_index_at(int which_nt) {
 452   jint ref_index = name_and_type_at(which_nt);
 453   return extract_low_short_from_int(ref_index);
 454 }
 455 
 456 
 457 int ConstantPool::signature_ref_index_at(int which_nt) {
 458   jint ref_index = name_and_type_at(which_nt);
 459   return extract_high_short_from_int(ref_index);
 460 }
 461 
 462 
 463 Klass* ConstantPool::klass_ref_at(int which, TRAPS) {
 464   return klass_at(klass_ref_index_at(which), CHECK_NULL);
 465 }
 466 
 467 
 468 Symbol* ConstantPool::klass_name_at(int which) {
 469   assert(tag_at(which).is_unresolved_klass() || tag_at(which).is_klass(),
 470          "Corrupted constant pool");
 471   // A resolved constantPool entry will contain a Klass*, otherwise a Symbol*.
 472   // It is not safe to rely on the tag bit's here, since we don't have a lock, and the entry and
 473   // tag is not updated atomicly.
 474   CPSlot entry = slot_at(which);
 475   if (entry.is_resolved()) {
 476     // Already resolved - return entry's name.
 477     assert(entry.get_klass()->is_klass(), "must be");
 478     return entry.get_klass()->name();
 479   } else {
 480     assert(entry.is_unresolved(), "must be either symbol or klass");
 481     return entry.get_symbol();
 482   }
 483 }
 484 
 485 Symbol* ConstantPool::klass_ref_at_noresolve(int which) {
 486   jint ref_index = klass_ref_index_at(which);
 487   return klass_at_noresolve(ref_index);
 488 }
 489 
 490 Symbol* ConstantPool::uncached_klass_ref_at_noresolve(int which) {
 491   jint ref_index = uncached_klass_ref_index_at(which);
 492   return klass_at_noresolve(ref_index);
 493 }
 494 
 495 char* ConstantPool::string_at_noresolve(int which) {
 496   Symbol* s = unresolved_string_at(which);
 497   if (s == NULL) {
 498     return (char*)"<pseudo-string>";
 499   } else {
 500     return unresolved_string_at(which)->as_C_string();
 501   }
 502 }
 503 
 504 BasicType ConstantPool::basic_type_for_signature_at(int which) {
 505   return FieldType::basic_type(symbol_at(which));
 506 }
 507 
 508 
 509 void ConstantPool::resolve_string_constants_impl(constantPoolHandle this_cp, TRAPS) {
 510   for (int index = 1; index < this_cp->length(); index++) { // Index 0 is unused
 511     if (this_cp->tag_at(index).is_string()) {
 512       this_cp->string_at(index, CHECK);
 513     }
 514   }
 515 }
 516 
 517 // Resolve all the classes in the constant pool.  If they are all resolved,
 518 // the constant pool is read-only.  Enhancement: allocate cp entries to
 519 // another metaspace, and copy to read-only or read-write space if this
 520 // bit is set.
 521 bool ConstantPool::resolve_class_constants(TRAPS) {
 522   constantPoolHandle cp(THREAD, this);
 523   for (int index = 1; index < length(); index++) { // Index 0 is unused
 524     if (tag_at(index).is_unresolved_klass() &&
 525         klass_at_if_loaded(cp, index) == NULL) {
 526       return false;
 527   }
 528   }
 529   // set_preresolution(); or some bit for future use
 530   return true;
 531 }
 532 
 533 Symbol* ConstantPool::exception_message(constantPoolHandle this_cp, int which, constantTag tag, oop pending_exception) {
 534   // Dig out the detailed message to reuse if possible
 535   Symbol* message = java_lang_Throwable::detail_message(pending_exception);
 536   if (message != NULL) {
 537     return message;
 538   }
 539 
 540   // Return specific message for the tag
 541   switch (tag.value()) {
 542   case JVM_CONSTANT_UnresolvedClass:
 543     // return the class name in the error message
 544     message = this_cp->klass_name_at(which);
 545     break;
 546   case JVM_CONSTANT_MethodHandle:
 547     // return the method handle name in the error message
 548     message = this_cp->method_handle_name_ref_at(which);
 549     break;
 550   case JVM_CONSTANT_MethodType:
 551     // return the method type signature in the error message
 552     message = this_cp->method_type_signature_at(which);
 553     break;
 554   default:
 555     ShouldNotReachHere();
 556   }
 557 
 558   return message;
 559 }
 560 
 561 void ConstantPool::throw_resolution_error(constantPoolHandle this_cp, int which, TRAPS) {
 562   Symbol* message = NULL;
 563   Symbol* error = SystemDictionary::find_resolution_error(this_cp, which, &message);
 564   assert(error != NULL && message != NULL, "checking");
 565   CLEAR_PENDING_EXCEPTION;
 566   ResourceMark rm;
 567   THROW_MSG(error, message->as_C_string());
 568 }
 569 
 570 // If resolution for Class, MethodHandle or MethodType fails, save the exception
 571 // in the resolution error table, so that the same exception is thrown again.
 572 void ConstantPool::save_and_throw_exception(constantPoolHandle this_cp, int which,
 573                                             constantTag tag, TRAPS) {
 574   Symbol* error = PENDING_EXCEPTION->klass()->name();
 575 
 576   int error_tag = tag.error_value();
 577 
 578   if (!PENDING_EXCEPTION->
 579     is_a(SystemDictionary::LinkageError_klass())) {
 580     // Just throw the exception and don't prevent these classes from
 581     // being loaded due to virtual machine errors like StackOverflow
 582     // and OutOfMemoryError, etc, or if the thread was hit by stop()
 583     // Needs clarification to section 5.4.3 of the VM spec (see 6308271)
 584   } else if (this_cp->tag_at(which).value() != error_tag) {
 585     Symbol* message = exception_message(this_cp, which, tag, PENDING_EXCEPTION);
 586     SystemDictionary::add_resolution_error(this_cp, which, error, message);
 587     // CAS in the tag.  If a thread beat us to registering this error that's fine.
 588     // If another thread resolved the reference, this is a race condition. This
 589     // thread may have had a security manager or something temporary.
 590     // This doesn't deterministically get an error.   So why do we save this?
 591     // We save this because jvmti can add classes to the bootclass path after
 592     // this error, so it needs to get the same error if the error is first.
 593     jbyte old_tag = Atomic::cmpxchg((jbyte)error_tag,
 594                             (jbyte*)this_cp->tag_addr_at(which), (jbyte)tag.value());
 595     if (old_tag != error_tag && old_tag != tag.value()) {
 596       // MethodHandles and MethodType doesn't change to resolved version.
 597       assert(this_cp->tag_at(which).is_klass(), "Wrong tag value");
 598       // Forget the exception and use the resolved class.
 599       CLEAR_PENDING_EXCEPTION;
 600     }
 601   } else {
 602     // some other thread put this in error state
 603     throw_resolution_error(this_cp, which, CHECK);
 604   }
 605 }
 606 
 607 // Called to resolve constants in the constant pool and return an oop.
 608 // Some constant pool entries cache their resolved oop. This is also
 609 // called to create oops from constants to use in arguments for invokedynamic
 610 oop ConstantPool::resolve_constant_at_impl(constantPoolHandle this_cp, int index, int cache_index, TRAPS) {
 611   oop result_oop = NULL;
 612   Handle throw_exception;
 613 
 614   if (cache_index == _possible_index_sentinel) {
 615     // It is possible that this constant is one which is cached in the objects.
 616     // We'll do a linear search.  This should be OK because this usage is rare.
 617     assert(index > 0, "valid index");
 618     cache_index = this_cp->cp_to_object_index(index);
 619   }
 620   assert(cache_index == _no_index_sentinel || cache_index >= 0, "");
 621   assert(index == _no_index_sentinel || index >= 0, "");
 622 
 623   if (cache_index >= 0) {
 624     result_oop = this_cp->resolved_references()->obj_at(cache_index);
 625     if (result_oop != NULL) {
 626       return result_oop;
 627       // That was easy...
 628     }
 629     index = this_cp->object_to_cp_index(cache_index);
 630   }
 631 
 632   jvalue prim_value;  // temp used only in a few cases below
 633 
 634   constantTag tag = this_cp->tag_at(index);
 635 
 636   switch (tag.value()) {
 637 
 638   case JVM_CONSTANT_UnresolvedClass:
 639   case JVM_CONSTANT_UnresolvedClassInError:
 640   case JVM_CONSTANT_Class:
 641     {
 642       assert(cache_index == _no_index_sentinel, "should not have been set");
 643       Klass* resolved = klass_at_impl(this_cp, index, true, CHECK_NULL);
 644       // ldc wants the java mirror.
 645       result_oop = resolved->java_mirror();
 646       break;
 647     }
 648 
 649   case JVM_CONSTANT_String:
 650     assert(cache_index != _no_index_sentinel, "should have been set");
 651     if (this_cp->is_pseudo_string_at(index)) {
 652       result_oop = this_cp->pseudo_string_at(index, cache_index);
 653       break;
 654     }
 655     result_oop = string_at_impl(this_cp, index, cache_index, CHECK_NULL);
 656     break;
 657 
 658   case JVM_CONSTANT_MethodHandleInError:
 659   case JVM_CONSTANT_MethodTypeInError:
 660     {
 661       throw_resolution_error(this_cp, index, CHECK_NULL);
 662       break;
 663     }
 664 
 665   case JVM_CONSTANT_MethodHandle:
 666     {
 667       int ref_kind                 = this_cp->method_handle_ref_kind_at(index);
 668       int callee_index             = this_cp->method_handle_klass_index_at(index);
 669       Symbol*  name =      this_cp->method_handle_name_ref_at(index);
 670       Symbol*  signature = this_cp->method_handle_signature_ref_at(index);
 671       if (PrintMiscellaneous)
 672         tty->print_cr("resolve JVM_CONSTANT_MethodHandle:%d [%d/%d/%d] %s.%s",
 673                       ref_kind, index, this_cp->method_handle_index_at(index),
 674                       callee_index, name->as_C_string(), signature->as_C_string());
 675       KlassHandle callee;
 676       { Klass* k = klass_at_impl(this_cp, callee_index, true, CHECK_NULL);
 677         callee = KlassHandle(THREAD, k);
 678       }
 679       KlassHandle klass(THREAD, this_cp->pool_holder());
 680       Handle value = SystemDictionary::link_method_handle_constant(klass, ref_kind,
 681                                                                    callee, name, signature,
 682                                                                    THREAD);
 683       result_oop = value();
 684       if (HAS_PENDING_EXCEPTION) {
 685         save_and_throw_exception(this_cp, index, tag, CHECK_NULL);
 686       }
 687       break;
 688     }
 689 
 690   case JVM_CONSTANT_MethodType:
 691     {
 692       Symbol*  signature = this_cp->method_type_signature_at(index);
 693       if (PrintMiscellaneous)
 694         tty->print_cr("resolve JVM_CONSTANT_MethodType [%d/%d] %s",
 695                       index, this_cp->method_type_index_at(index),
 696                       signature->as_C_string());
 697       KlassHandle klass(THREAD, this_cp->pool_holder());
 698       Handle value = SystemDictionary::find_method_handle_type(signature, klass, THREAD);
 699       result_oop = value();
 700       if (HAS_PENDING_EXCEPTION) {
 701         save_and_throw_exception(this_cp, index, tag, CHECK_NULL);
 702       }
 703       break;
 704     }
 705 
 706   case JVM_CONSTANT_Integer:
 707     assert(cache_index == _no_index_sentinel, "should not have been set");
 708     prim_value.i = this_cp->int_at(index);
 709     result_oop = java_lang_boxing_object::create(T_INT, &prim_value, CHECK_NULL);
 710     break;
 711 
 712   case JVM_CONSTANT_Float:
 713     assert(cache_index == _no_index_sentinel, "should not have been set");
 714     prim_value.f = this_cp->float_at(index);
 715     result_oop = java_lang_boxing_object::create(T_FLOAT, &prim_value, CHECK_NULL);
 716     break;
 717 
 718   case JVM_CONSTANT_Long:
 719     assert(cache_index == _no_index_sentinel, "should not have been set");
 720     prim_value.j = this_cp->long_at(index);
 721     result_oop = java_lang_boxing_object::create(T_LONG, &prim_value, CHECK_NULL);
 722     break;
 723 
 724   case JVM_CONSTANT_Double:
 725     assert(cache_index == _no_index_sentinel, "should not have been set");
 726     prim_value.d = this_cp->double_at(index);
 727     result_oop = java_lang_boxing_object::create(T_DOUBLE, &prim_value, CHECK_NULL);
 728     break;
 729 
 730   default:
 731     DEBUG_ONLY( tty->print_cr("*** %p: tag at CP[%d/%d] = %d",
 732                               this_cp(), index, cache_index, tag.value()));
 733     assert(false, "unexpected constant tag");
 734     break;
 735   }
 736 
 737   if (cache_index >= 0) {
 738     // Benign race condition:  resolved_references may already be filled in.
 739     // The important thing here is that all threads pick up the same result.
 740     // It doesn't matter which racing thread wins, as long as only one
 741     // result is used by all threads, and all future queries.
 742     oop old_result = this_cp->resolved_references()->atomic_compare_exchange_oop(cache_index, result_oop, NULL);
 743     if (old_result == NULL) {
 744       return result_oop;  // was installed
 745     } else {
 746       // Return the winning thread's result.  This can be different than
 747       // the result here for MethodHandles.
 748       return old_result;
 749     }
 750   } else {
 751     return result_oop;
 752   }
 753 }
 754 
 755 oop ConstantPool::uncached_string_at(int which, TRAPS) {
 756   Symbol* sym = unresolved_string_at(which);
 757   oop str = StringTable::intern(sym, CHECK_(NULL));
 758   assert(java_lang_String::is_instance(str), "must be string");
 759   return str;
 760 }
 761 
 762 
 763 oop ConstantPool::resolve_bootstrap_specifier_at_impl(constantPoolHandle this_cp, int index, TRAPS) {
 764   assert(this_cp->tag_at(index).is_invoke_dynamic(), "Corrupted constant pool");
 765 
 766   Handle bsm;
 767   int argc;
 768   {
 769     // JVM_CONSTANT_InvokeDynamic is an ordered pair of [bootm, name&type], plus optional arguments
 770     // The bootm, being a JVM_CONSTANT_MethodHandle, has its own cache entry.
 771     // It is accompanied by the optional arguments.
 772     int bsm_index = this_cp->invoke_dynamic_bootstrap_method_ref_index_at(index);
 773     oop bsm_oop = this_cp->resolve_possibly_cached_constant_at(bsm_index, CHECK_NULL);
 774     if (!java_lang_invoke_MethodHandle::is_instance(bsm_oop)) {
 775       THROW_MSG_NULL(vmSymbols::java_lang_LinkageError(), "BSM not an MethodHandle");
 776     }
 777 
 778     // Extract the optional static arguments.
 779     argc = this_cp->invoke_dynamic_argument_count_at(index);
 780     if (argc == 0)  return bsm_oop;
 781 
 782     bsm = Handle(THREAD, bsm_oop);
 783   }
 784 
 785   objArrayHandle info;
 786   {
 787     objArrayOop info_oop = oopFactory::new_objArray(SystemDictionary::Object_klass(), 1+argc, CHECK_NULL);
 788     info = objArrayHandle(THREAD, info_oop);
 789   }
 790 
 791   info->obj_at_put(0, bsm());
 792   for (int i = 0; i < argc; i++) {
 793     int arg_index = this_cp->invoke_dynamic_argument_index_at(index, i);
 794     oop arg_oop = this_cp->resolve_possibly_cached_constant_at(arg_index, CHECK_NULL);
 795     info->obj_at_put(1+i, arg_oop);
 796   }
 797 
 798   return info();
 799 }
 800 
 801 oop ConstantPool::string_at_impl(constantPoolHandle this_cp, int which, int obj_index, TRAPS) {
 802   // If the string has already been interned, this entry will be non-null
 803   oop str = this_cp->resolved_references()->obj_at(obj_index);
 804   if (str != NULL) return str;
 805   Symbol* sym = this_cp->unresolved_string_at(which);
 806   str = StringTable::intern(sym, CHECK_(NULL));
 807   this_cp->string_at_put(which, obj_index, str);
 808   assert(java_lang_String::is_instance(str), "must be string");
 809   return str;
 810 }
 811 
 812 
 813 bool ConstantPool::klass_name_at_matches(instanceKlassHandle k,
 814                                                 int which) {
 815   // Names are interned, so we can compare Symbol*s directly
 816   Symbol* cp_name = klass_name_at(which);
 817   return (cp_name == k->name());
 818 }
 819 
 820 
 821 // Iterate over symbols and decrement ones which are Symbol*s
 822 // This is done during GC.
 823 // Only decrement the UTF8 symbols. Unresolved classes and strings point to
 824 // these symbols but didn't increment the reference count.
 825 void ConstantPool::unreference_symbols() {
 826   for (int index = 1; index < length(); index++) { // Index 0 is unused
 827     constantTag tag = tag_at(index);
 828     if (tag.is_symbol()) {
 829       symbol_at(index)->decrement_refcount();
 830     }
 831   }
 832 }
 833 
 834 
 835 // Compare this constant pool's entry at index1 to the constant pool
 836 // cp2's entry at index2.
 837 bool ConstantPool::compare_entry_to(int index1, constantPoolHandle cp2,
 838        int index2, TRAPS) {
 839 
 840   // The error tags are equivalent to non-error tags when comparing
 841   jbyte t1 = tag_at(index1).non_error_value();
 842   jbyte t2 = cp2->tag_at(index2).non_error_value();
 843 
 844   if (t1 != t2) {
 845     // Not the same entry type so there is nothing else to check. Note
 846     // that this style of checking will consider resolved/unresolved
 847     // class pairs as different.
 848     // From the ConstantPool* API point of view, this is correct
 849     // behavior. See VM_RedefineClasses::merge_constant_pools() to see how this
 850     // plays out in the context of ConstantPool* merging.
 851     return false;
 852   }
 853 
 854   switch (t1) {
 855   case JVM_CONSTANT_Class:
 856   {
 857     Klass* k1 = klass_at(index1, CHECK_false);
 858     Klass* k2 = cp2->klass_at(index2, CHECK_false);
 859     if (k1 == k2) {
 860       return true;
 861     }
 862   } break;
 863 
 864   case JVM_CONSTANT_ClassIndex:
 865   {
 866     int recur1 = klass_index_at(index1);
 867     int recur2 = cp2->klass_index_at(index2);
 868     bool match = compare_entry_to(recur1, cp2, recur2, CHECK_false);
 869     if (match) {
 870       return true;
 871     }
 872   } break;
 873 
 874   case JVM_CONSTANT_Double:
 875   {
 876     jdouble d1 = double_at(index1);
 877     jdouble d2 = cp2->double_at(index2);
 878     if (d1 == d2) {
 879       return true;
 880     }
 881   } break;
 882 
 883   case JVM_CONSTANT_Fieldref:
 884   case JVM_CONSTANT_InterfaceMethodref:
 885   case JVM_CONSTANT_Methodref:
 886   {
 887     int recur1 = uncached_klass_ref_index_at(index1);
 888     int recur2 = cp2->uncached_klass_ref_index_at(index2);
 889     bool match = compare_entry_to(recur1, cp2, recur2, CHECK_false);
 890     if (match) {
 891       recur1 = uncached_name_and_type_ref_index_at(index1);
 892       recur2 = cp2->uncached_name_and_type_ref_index_at(index2);
 893       match = compare_entry_to(recur1, cp2, recur2, CHECK_false);
 894       if (match) {
 895         return true;
 896       }
 897     }
 898   } break;
 899 
 900   case JVM_CONSTANT_Float:
 901   {
 902     jfloat f1 = float_at(index1);
 903     jfloat f2 = cp2->float_at(index2);
 904     if (f1 == f2) {
 905       return true;
 906     }
 907   } break;
 908 
 909   case JVM_CONSTANT_Integer:
 910   {
 911     jint i1 = int_at(index1);
 912     jint i2 = cp2->int_at(index2);
 913     if (i1 == i2) {
 914       return true;
 915     }
 916   } break;
 917 
 918   case JVM_CONSTANT_Long:
 919   {
 920     jlong l1 = long_at(index1);
 921     jlong l2 = cp2->long_at(index2);
 922     if (l1 == l2) {
 923       return true;
 924     }
 925   } break;
 926 
 927   case JVM_CONSTANT_NameAndType:
 928   {
 929     int recur1 = name_ref_index_at(index1);
 930     int recur2 = cp2->name_ref_index_at(index2);
 931     bool match = compare_entry_to(recur1, cp2, recur2, CHECK_false);
 932     if (match) {
 933       recur1 = signature_ref_index_at(index1);
 934       recur2 = cp2->signature_ref_index_at(index2);
 935       match = compare_entry_to(recur1, cp2, recur2, CHECK_false);
 936       if (match) {
 937         return true;
 938       }
 939     }
 940   } break;
 941 
 942   case JVM_CONSTANT_StringIndex:
 943   {
 944     int recur1 = string_index_at(index1);
 945     int recur2 = cp2->string_index_at(index2);
 946     bool match = compare_entry_to(recur1, cp2, recur2, CHECK_false);
 947     if (match) {
 948       return true;
 949     }
 950   } break;
 951 
 952   case JVM_CONSTANT_UnresolvedClass:
 953   {
 954     Symbol* k1 = klass_name_at(index1);
 955     Symbol* k2 = cp2->klass_name_at(index2);
 956     if (k1 == k2) {
 957       return true;
 958     }
 959   } break;
 960 
 961   case JVM_CONSTANT_MethodType:
 962   {
 963     int k1 = method_type_index_at_error_ok(index1);
 964     int k2 = cp2->method_type_index_at_error_ok(index2);
 965     bool match = compare_entry_to(k1, cp2, k2, CHECK_false);
 966     if (match) {
 967       return true;
 968     }
 969   } break;
 970 
 971   case JVM_CONSTANT_MethodHandle:
 972   {
 973     int k1 = method_handle_ref_kind_at_error_ok(index1);
 974     int k2 = cp2->method_handle_ref_kind_at_error_ok(index2);
 975     if (k1 == k2) {
 976       int i1 = method_handle_index_at_error_ok(index1);
 977       int i2 = cp2->method_handle_index_at_error_ok(index2);
 978       bool match = compare_entry_to(i1, cp2, i2, CHECK_false);
 979       if (match) {
 980         return true;
 981       }
 982     }
 983   } break;
 984 
 985   case JVM_CONSTANT_InvokeDynamic:
 986   {
 987     int k1 = invoke_dynamic_name_and_type_ref_index_at(index1);
 988     int k2 = cp2->invoke_dynamic_name_and_type_ref_index_at(index2);
 989     int i1 = invoke_dynamic_bootstrap_specifier_index(index1);
 990     int i2 = cp2->invoke_dynamic_bootstrap_specifier_index(index2);
 991     // separate statements and variables because CHECK_false is used
 992     bool match_entry = compare_entry_to(k1, cp2, k2, CHECK_false);
 993     bool match_operand = compare_operand_to(i1, cp2, i2, CHECK_false);
 994     return (match_entry && match_operand);
 995   } break;
 996 
 997   case JVM_CONSTANT_String:
 998   {
 999     Symbol* s1 = unresolved_string_at(index1);
1000     Symbol* s2 = cp2->unresolved_string_at(index2);
1001     if (s1 == s2) {
1002       return true;
1003     }
1004   } break;
1005 
1006   case JVM_CONSTANT_Utf8:
1007   {
1008     Symbol* s1 = symbol_at(index1);
1009     Symbol* s2 = cp2->symbol_at(index2);
1010     if (s1 == s2) {
1011       return true;
1012     }
1013   } break;
1014 
1015   // Invalid is used as the tag for the second constant pool entry
1016   // occupied by JVM_CONSTANT_Double or JVM_CONSTANT_Long. It should
1017   // not be seen by itself.
1018   case JVM_CONSTANT_Invalid: // fall through
1019 
1020   default:
1021     ShouldNotReachHere();
1022     break;
1023   }
1024 
1025   return false;
1026 } // end compare_entry_to()
1027 
1028 
1029 // Resize the operands array with delta_len and delta_size.
1030 // Used in RedefineClasses for CP merge.
1031 void ConstantPool::resize_operands(int delta_len, int delta_size, TRAPS) {
1032   int old_len  = operand_array_length(operands());
1033   int new_len  = old_len + delta_len;
1034   int min_len  = (delta_len > 0) ? old_len : new_len;
1035 
1036   int old_size = operands()->length();
1037   int new_size = old_size + delta_size;
1038   int min_size = (delta_size > 0) ? old_size : new_size;
1039 
1040   ClassLoaderData* loader_data = pool_holder()->class_loader_data();
1041   Array<u2>* new_ops = MetadataFactory::new_array<u2>(loader_data, new_size, CHECK);
1042 
1043   // Set index in the resized array for existing elements only
1044   for (int idx = 0; idx < min_len; idx++) {
1045     int offset = operand_offset_at(idx);                       // offset in original array
1046     operand_offset_at_put(new_ops, idx, offset + 2*delta_len); // offset in resized array
1047   }
1048   // Copy the bootstrap specifiers only
1049   Copy::conjoint_memory_atomic(operands()->adr_at(2*old_len),
1050                                new_ops->adr_at(2*new_len),
1051                                (min_size - 2*min_len) * sizeof(u2));
1052   // Explicitly deallocate old operands array.
1053   // Note, it is not needed for 7u backport.
1054   if ( operands() != NULL) { // the safety check
1055     MetadataFactory::free_array<u2>(loader_data, operands());
1056   }
1057   set_operands(new_ops);
1058 } // end resize_operands()
1059 
1060 
1061 // Extend the operands array with the length and size of the ext_cp operands.
1062 // Used in RedefineClasses for CP merge.
1063 void ConstantPool::extend_operands(constantPoolHandle ext_cp, TRAPS) {
1064   int delta_len = operand_array_length(ext_cp->operands());
1065   if (delta_len == 0) {
1066     return; // nothing to do
1067   }
1068   int delta_size = ext_cp->operands()->length();
1069 
1070   assert(delta_len  > 0 && delta_size > 0, "extended operands array must be bigger");
1071 
1072   if (operand_array_length(operands()) == 0) {
1073     ClassLoaderData* loader_data = pool_holder()->class_loader_data();
1074     Array<u2>* new_ops = MetadataFactory::new_array<u2>(loader_data, delta_size, CHECK);
1075     // The first element index defines the offset of second part
1076     operand_offset_at_put(new_ops, 0, 2*delta_len); // offset in new array
1077     set_operands(new_ops);
1078   } else {
1079     resize_operands(delta_len, delta_size, CHECK);
1080   }
1081 
1082 } // end extend_operands()
1083 
1084 
1085 // Shrink the operands array to a smaller array with new_len length.
1086 // Used in RedefineClasses for CP merge.
1087 void ConstantPool::shrink_operands(int new_len, TRAPS) {
1088   int old_len = operand_array_length(operands());
1089   if (new_len == old_len) {
1090     return; // nothing to do
1091   }
1092   assert(new_len < old_len, "shrunken operands array must be smaller");
1093 
1094   int free_base  = operand_next_offset_at(new_len - 1);
1095   int delta_len  = new_len - old_len;
1096   int delta_size = 2*delta_len + free_base - operands()->length();
1097 
1098   resize_operands(delta_len, delta_size, CHECK);
1099 
1100 } // end shrink_operands()
1101 
1102 
1103 void ConstantPool::copy_operands(constantPoolHandle from_cp,
1104                                  constantPoolHandle to_cp,
1105                                  TRAPS) {
1106 
1107   int from_oplen = operand_array_length(from_cp->operands());
1108   int old_oplen  = operand_array_length(to_cp->operands());
1109   if (from_oplen != 0) {
1110     ClassLoaderData* loader_data = to_cp->pool_holder()->class_loader_data();
1111     // append my operands to the target's operands array
1112     if (old_oplen == 0) {
1113       // Can't just reuse from_cp's operand list because of deallocation issues
1114       int len = from_cp->operands()->length();
1115       Array<u2>* new_ops = MetadataFactory::new_array<u2>(loader_data, len, CHECK);
1116       Copy::conjoint_memory_atomic(
1117           from_cp->operands()->adr_at(0), new_ops->adr_at(0), len * sizeof(u2));
1118       to_cp->set_operands(new_ops);
1119     } else {
1120       int old_len  = to_cp->operands()->length();
1121       int from_len = from_cp->operands()->length();
1122       int old_off  = old_oplen * sizeof(u2);
1123       int from_off = from_oplen * sizeof(u2);
1124       // Use the metaspace for the destination constant pool
1125       Array<u2>* new_operands = MetadataFactory::new_array<u2>(loader_data, old_len + from_len, CHECK);
1126       int fillp = 0, len = 0;
1127       // first part of dest
1128       Copy::conjoint_memory_atomic(to_cp->operands()->adr_at(0),
1129                                    new_operands->adr_at(fillp),
1130                                    (len = old_off) * sizeof(u2));
1131       fillp += len;
1132       // first part of src
1133       Copy::conjoint_memory_atomic(from_cp->operands()->adr_at(0),
1134                                    new_operands->adr_at(fillp),
1135                                    (len = from_off) * sizeof(u2));
1136       fillp += len;
1137       // second part of dest
1138       Copy::conjoint_memory_atomic(to_cp->operands()->adr_at(old_off),
1139                                    new_operands->adr_at(fillp),
1140                                    (len = old_len - old_off) * sizeof(u2));
1141       fillp += len;
1142       // second part of src
1143       Copy::conjoint_memory_atomic(from_cp->operands()->adr_at(from_off),
1144                                    new_operands->adr_at(fillp),
1145                                    (len = from_len - from_off) * sizeof(u2));
1146       fillp += len;
1147       assert(fillp == new_operands->length(), "");
1148 
1149       // Adjust indexes in the first part of the copied operands array.
1150       for (int j = 0; j < from_oplen; j++) {
1151         int offset = operand_offset_at(new_operands, old_oplen + j);
1152         assert(offset == operand_offset_at(from_cp->operands(), j), "correct copy");
1153         offset += old_len;  // every new tuple is preceded by old_len extra u2's
1154         operand_offset_at_put(new_operands, old_oplen + j, offset);
1155       }
1156 
1157       // replace target operands array with combined array
1158       to_cp->set_operands(new_operands);
1159     }
1160   }
1161 } // end copy_operands()
1162 
1163 
1164 // Copy this constant pool's entries at start_i to end_i (inclusive)
1165 // to the constant pool to_cp's entries starting at to_i. A total of
1166 // (end_i - start_i) + 1 entries are copied.
1167 void ConstantPool::copy_cp_to_impl(constantPoolHandle from_cp, int start_i, int end_i,
1168        constantPoolHandle to_cp, int to_i, TRAPS) {
1169 
1170 
1171   int dest_i = to_i;  // leave original alone for debug purposes
1172 
1173   for (int src_i = start_i; src_i <= end_i; /* see loop bottom */ ) {
1174     copy_entry_to(from_cp, src_i, to_cp, dest_i, CHECK);
1175 
1176     switch (from_cp->tag_at(src_i).value()) {
1177     case JVM_CONSTANT_Double:
1178     case JVM_CONSTANT_Long:
1179       // double and long take two constant pool entries
1180       src_i += 2;
1181       dest_i += 2;
1182       break;
1183 
1184     default:
1185       // all others take one constant pool entry
1186       src_i++;
1187       dest_i++;
1188       break;
1189     }
1190   }
1191   copy_operands(from_cp, to_cp, CHECK);
1192 
1193 } // end copy_cp_to_impl()
1194 
1195 
1196 // Copy this constant pool's entry at from_i to the constant pool
1197 // to_cp's entry at to_i.
1198 void ConstantPool::copy_entry_to(constantPoolHandle from_cp, int from_i,
1199                                         constantPoolHandle to_cp, int to_i,
1200                                         TRAPS) {
1201 
1202   int tag = from_cp->tag_at(from_i).value();
1203   switch (tag) {
1204   case JVM_CONSTANT_Class:
1205   {
1206     Klass* k = from_cp->klass_at(from_i, CHECK);
1207     to_cp->klass_at_put(to_i, k);
1208   } break;
1209 
1210   case JVM_CONSTANT_ClassIndex:
1211   {
1212     jint ki = from_cp->klass_index_at(from_i);
1213     to_cp->klass_index_at_put(to_i, ki);
1214   } break;
1215 
1216   case JVM_CONSTANT_Double:
1217   {
1218     jdouble d = from_cp->double_at(from_i);
1219     to_cp->double_at_put(to_i, d);
1220     // double takes two constant pool entries so init second entry's tag
1221     to_cp->tag_at_put(to_i + 1, JVM_CONSTANT_Invalid);
1222   } break;
1223 
1224   case JVM_CONSTANT_Fieldref:
1225   {
1226     int class_index = from_cp->uncached_klass_ref_index_at(from_i);
1227     int name_and_type_index = from_cp->uncached_name_and_type_ref_index_at(from_i);
1228     to_cp->field_at_put(to_i, class_index, name_and_type_index);
1229   } break;
1230 
1231   case JVM_CONSTANT_Float:
1232   {
1233     jfloat f = from_cp->float_at(from_i);
1234     to_cp->float_at_put(to_i, f);
1235   } break;
1236 
1237   case JVM_CONSTANT_Integer:
1238   {
1239     jint i = from_cp->int_at(from_i);
1240     to_cp->int_at_put(to_i, i);
1241   } break;
1242 
1243   case JVM_CONSTANT_InterfaceMethodref:
1244   {
1245     int class_index = from_cp->uncached_klass_ref_index_at(from_i);
1246     int name_and_type_index = from_cp->uncached_name_and_type_ref_index_at(from_i);
1247     to_cp->interface_method_at_put(to_i, class_index, name_and_type_index);
1248   } break;
1249 
1250   case JVM_CONSTANT_Long:
1251   {
1252     jlong l = from_cp->long_at(from_i);
1253     to_cp->long_at_put(to_i, l);
1254     // long takes two constant pool entries so init second entry's tag
1255     to_cp->tag_at_put(to_i + 1, JVM_CONSTANT_Invalid);
1256   } break;
1257 
1258   case JVM_CONSTANT_Methodref:
1259   {
1260     int class_index = from_cp->uncached_klass_ref_index_at(from_i);
1261     int name_and_type_index = from_cp->uncached_name_and_type_ref_index_at(from_i);
1262     to_cp->method_at_put(to_i, class_index, name_and_type_index);
1263   } break;
1264 
1265   case JVM_CONSTANT_NameAndType:
1266   {
1267     int name_ref_index = from_cp->name_ref_index_at(from_i);
1268     int signature_ref_index = from_cp->signature_ref_index_at(from_i);
1269     to_cp->name_and_type_at_put(to_i, name_ref_index, signature_ref_index);
1270   } break;
1271 
1272   case JVM_CONSTANT_StringIndex:
1273   {
1274     jint si = from_cp->string_index_at(from_i);
1275     to_cp->string_index_at_put(to_i, si);
1276   } break;
1277 
1278   case JVM_CONSTANT_UnresolvedClass:
1279   case JVM_CONSTANT_UnresolvedClassInError:
1280   {
1281     // Can be resolved after checking tag, so check the slot first.
1282     CPSlot entry = from_cp->slot_at(from_i);
1283     if (entry.is_resolved()) {
1284       assert(entry.get_klass()->is_klass(), "must be");
1285       // Already resolved
1286       to_cp->klass_at_put(to_i, entry.get_klass());
1287     } else {
1288       to_cp->unresolved_klass_at_put(to_i, entry.get_symbol());
1289     }
1290   } break;
1291 
1292   case JVM_CONSTANT_String:
1293   {
1294     Symbol* s = from_cp->unresolved_string_at(from_i);
1295     to_cp->unresolved_string_at_put(to_i, s);
1296   } break;
1297 
1298   case JVM_CONSTANT_Utf8:
1299   {
1300     Symbol* s = from_cp->symbol_at(from_i);
1301     // Need to increase refcount, the old one will be thrown away and deferenced
1302     s->increment_refcount();
1303     to_cp->symbol_at_put(to_i, s);
1304   } break;
1305 
1306   case JVM_CONSTANT_MethodType:
1307   case JVM_CONSTANT_MethodTypeInError:
1308   {
1309     jint k = from_cp->method_type_index_at_error_ok(from_i);
1310     to_cp->method_type_index_at_put(to_i, k);
1311   } break;
1312 
1313   case JVM_CONSTANT_MethodHandle:
1314   case JVM_CONSTANT_MethodHandleInError:
1315   {
1316     int k1 = from_cp->method_handle_ref_kind_at_error_ok(from_i);
1317     int k2 = from_cp->method_handle_index_at_error_ok(from_i);
1318     to_cp->method_handle_index_at_put(to_i, k1, k2);
1319   } break;
1320 
1321   case JVM_CONSTANT_InvokeDynamic:
1322   {
1323     int k1 = from_cp->invoke_dynamic_bootstrap_specifier_index(from_i);
1324     int k2 = from_cp->invoke_dynamic_name_and_type_ref_index_at(from_i);
1325     k1 += operand_array_length(to_cp->operands());  // to_cp might already have operands
1326     to_cp->invoke_dynamic_at_put(to_i, k1, k2);
1327   } break;
1328 
1329   // Invalid is used as the tag for the second constant pool entry
1330   // occupied by JVM_CONSTANT_Double or JVM_CONSTANT_Long. It should
1331   // not be seen by itself.
1332   case JVM_CONSTANT_Invalid: // fall through
1333 
1334   default:
1335   {
1336     ShouldNotReachHere();
1337   } break;
1338   }
1339 } // end copy_entry_to()
1340 
1341 
1342 // Search constant pool search_cp for an entry that matches this
1343 // constant pool's entry at pattern_i. Returns the index of a
1344 // matching entry or zero (0) if there is no matching entry.
1345 int ConstantPool::find_matching_entry(int pattern_i,
1346       constantPoolHandle search_cp, TRAPS) {
1347 
1348   // index zero (0) is not used
1349   for (int i = 1; i < search_cp->length(); i++) {
1350     bool found = compare_entry_to(pattern_i, search_cp, i, CHECK_0);
1351     if (found) {
1352       return i;
1353     }
1354   }
1355 
1356   return 0;  // entry not found; return unused index zero (0)
1357 } // end find_matching_entry()
1358 
1359 
1360 // Compare this constant pool's bootstrap specifier at idx1 to the constant pool
1361 // cp2's bootstrap specifier at idx2.
1362 bool ConstantPool::compare_operand_to(int idx1, constantPoolHandle cp2, int idx2, TRAPS) {
1363   int k1 = operand_bootstrap_method_ref_index_at(idx1);
1364   int k2 = cp2->operand_bootstrap_method_ref_index_at(idx2);
1365   bool match = compare_entry_to(k1, cp2, k2, CHECK_false);
1366 
1367   if (!match) {
1368     return false;
1369   }
1370   int argc = operand_argument_count_at(idx1);
1371   if (argc == cp2->operand_argument_count_at(idx2)) {
1372     for (int j = 0; j < argc; j++) {
1373       k1 = operand_argument_index_at(idx1, j);
1374       k2 = cp2->operand_argument_index_at(idx2, j);
1375       match = compare_entry_to(k1, cp2, k2, CHECK_false);
1376       if (!match) {
1377         return false;
1378       }
1379     }
1380     return true;           // got through loop; all elements equal
1381   }
1382   return false;
1383 } // end compare_operand_to()
1384 
1385 // Search constant pool search_cp for a bootstrap specifier that matches
1386 // this constant pool's bootstrap specifier at pattern_i index.
1387 // Return the index of a matching bootstrap specifier or (-1) if there is no match.
1388 int ConstantPool::find_matching_operand(int pattern_i,
1389                     constantPoolHandle search_cp, int search_len, TRAPS) {
1390   for (int i = 0; i < search_len; i++) {
1391     bool found = compare_operand_to(pattern_i, search_cp, i, CHECK_(-1));
1392     if (found) {
1393       return i;
1394     }
1395   }
1396   return -1;  // bootstrap specifier not found; return unused index (-1)
1397 } // end find_matching_operand()
1398 
1399 
1400 #ifndef PRODUCT
1401 
1402 const char* ConstantPool::printable_name_at(int which) {
1403 
1404   constantTag tag = tag_at(which);
1405 
1406   if (tag.is_string()) {
1407     return string_at_noresolve(which);
1408   } else if (tag.is_klass() || tag.is_unresolved_klass()) {
1409     return klass_name_at(which)->as_C_string();
1410   } else if (tag.is_symbol()) {
1411     return symbol_at(which)->as_C_string();
1412   }
1413   return "";
1414 }
1415 
1416 #endif // PRODUCT
1417 
1418 
1419 // JVMTI GetConstantPool support
1420 
1421 // For debugging of constant pool
1422 const bool debug_cpool = false;
1423 
1424 #define DBG(code) do { if (debug_cpool) { (code); } } while(0)
1425 
1426 static void print_cpool_bytes(jint cnt, u1 *bytes) {
1427   const char* WARN_MSG = "Must not be such entry!";
1428   jint size = 0;
1429   u2   idx1, idx2;
1430 
1431   for (jint idx = 1; idx < cnt; idx++) {
1432     jint ent_size = 0;
1433     u1   tag  = *bytes++;
1434     size++;                       // count tag
1435 
1436     printf("const #%03d, tag: %02d ", idx, tag);
1437     switch(tag) {
1438       case JVM_CONSTANT_Invalid: {
1439         printf("Invalid");
1440         break;
1441       }
1442       case JVM_CONSTANT_Unicode: {
1443         printf("Unicode      %s", WARN_MSG);
1444         break;
1445       }
1446       case JVM_CONSTANT_Utf8: {
1447         u2 len = Bytes::get_Java_u2(bytes);
1448         char str[128];
1449         if (len > 127) {
1450            len = 127;
1451         }
1452         strncpy(str, (char *) (bytes+2), len);
1453         str[len] = '\0';
1454         printf("Utf8          \"%s\"", str);
1455         ent_size = 2 + len;
1456         break;
1457       }
1458       case JVM_CONSTANT_Integer: {
1459         u4 val = Bytes::get_Java_u4(bytes);
1460         printf("int          %d", *(int *) &val);
1461         ent_size = 4;
1462         break;
1463       }
1464       case JVM_CONSTANT_Float: {
1465         u4 val = Bytes::get_Java_u4(bytes);
1466         printf("float        %5.3ff", *(float *) &val);
1467         ent_size = 4;
1468         break;
1469       }
1470       case JVM_CONSTANT_Long: {
1471         u8 val = Bytes::get_Java_u8(bytes);
1472         printf("long         "INT64_FORMAT, (int64_t) *(jlong *) &val);
1473         ent_size = 8;
1474         idx++; // Long takes two cpool slots
1475         break;
1476       }
1477       case JVM_CONSTANT_Double: {
1478         u8 val = Bytes::get_Java_u8(bytes);
1479         printf("double       %5.3fd", *(jdouble *)&val);
1480         ent_size = 8;
1481         idx++; // Double takes two cpool slots
1482         break;
1483       }
1484       case JVM_CONSTANT_Class: {
1485         idx1 = Bytes::get_Java_u2(bytes);
1486         printf("class        #%03d", idx1);
1487         ent_size = 2;
1488         break;
1489       }
1490       case JVM_CONSTANT_String: {
1491         idx1 = Bytes::get_Java_u2(bytes);
1492         printf("String       #%03d", idx1);
1493         ent_size = 2;
1494         break;
1495       }
1496       case JVM_CONSTANT_Fieldref: {
1497         idx1 = Bytes::get_Java_u2(bytes);
1498         idx2 = Bytes::get_Java_u2(bytes+2);
1499         printf("Field        #%03d, #%03d", (int) idx1, (int) idx2);
1500         ent_size = 4;
1501         break;
1502       }
1503       case JVM_CONSTANT_Methodref: {
1504         idx1 = Bytes::get_Java_u2(bytes);
1505         idx2 = Bytes::get_Java_u2(bytes+2);
1506         printf("Method       #%03d, #%03d", idx1, idx2);
1507         ent_size = 4;
1508         break;
1509       }
1510       case JVM_CONSTANT_InterfaceMethodref: {
1511         idx1 = Bytes::get_Java_u2(bytes);
1512         idx2 = Bytes::get_Java_u2(bytes+2);
1513         printf("InterfMethod #%03d, #%03d", idx1, idx2);
1514         ent_size = 4;
1515         break;
1516       }
1517       case JVM_CONSTANT_NameAndType: {
1518         idx1 = Bytes::get_Java_u2(bytes);
1519         idx2 = Bytes::get_Java_u2(bytes+2);
1520         printf("NameAndType  #%03d, #%03d", idx1, idx2);
1521         ent_size = 4;
1522         break;
1523       }
1524       case JVM_CONSTANT_ClassIndex: {
1525         printf("ClassIndex  %s", WARN_MSG);
1526         break;
1527       }
1528       case JVM_CONSTANT_UnresolvedClass: {
1529         printf("UnresolvedClass: %s", WARN_MSG);
1530         break;
1531       }
1532       case JVM_CONSTANT_UnresolvedClassInError: {
1533         printf("UnresolvedClassInErr: %s", WARN_MSG);
1534         break;
1535       }
1536       case JVM_CONSTANT_StringIndex: {
1537         printf("StringIndex: %s", WARN_MSG);
1538         break;
1539       }
1540     }
1541     printf(";\n");
1542     bytes += ent_size;
1543     size  += ent_size;
1544   }
1545   printf("Cpool size: %d\n", size);
1546   fflush(0);
1547   return;
1548 } /* end print_cpool_bytes */
1549 
1550 
1551 // Returns size of constant pool entry.
1552 jint ConstantPool::cpool_entry_size(jint idx) {
1553   switch(tag_at(idx).value()) {
1554     case JVM_CONSTANT_Invalid:
1555     case JVM_CONSTANT_Unicode:
1556       return 1;
1557 
1558     case JVM_CONSTANT_Utf8:
1559       return 3 + symbol_at(idx)->utf8_length();
1560 
1561     case JVM_CONSTANT_Class:
1562     case JVM_CONSTANT_String:
1563     case JVM_CONSTANT_ClassIndex:
1564     case JVM_CONSTANT_UnresolvedClass:
1565     case JVM_CONSTANT_UnresolvedClassInError:
1566     case JVM_CONSTANT_StringIndex:
1567     case JVM_CONSTANT_MethodType:
1568     case JVM_CONSTANT_MethodTypeInError:
1569       return 3;
1570 
1571     case JVM_CONSTANT_MethodHandle:
1572     case JVM_CONSTANT_MethodHandleInError:
1573       return 4; //tag, ref_kind, ref_index
1574 
1575     case JVM_CONSTANT_Integer:
1576     case JVM_CONSTANT_Float:
1577     case JVM_CONSTANT_Fieldref:
1578     case JVM_CONSTANT_Methodref:
1579     case JVM_CONSTANT_InterfaceMethodref:
1580     case JVM_CONSTANT_NameAndType:
1581       return 5;
1582 
1583     case JVM_CONSTANT_InvokeDynamic:
1584       // u1 tag, u2 bsm, u2 nt
1585       return 5;
1586 
1587     case JVM_CONSTANT_Long:
1588     case JVM_CONSTANT_Double:
1589       return 9;
1590   }
1591   assert(false, "cpool_entry_size: Invalid constant pool entry tag");
1592   return 1;
1593 } /* end cpool_entry_size */
1594 
1595 
1596 // SymbolHashMap is used to find a constant pool index from a string.
1597 // This function fills in SymbolHashMaps, one for utf8s and one for
1598 // class names, returns size of the cpool raw bytes.
1599 jint ConstantPool::hash_entries_to(SymbolHashMap *symmap,
1600                                    SymbolHashMap *classmap) {
1601   jint size = 0;
1602 
1603   for (u2 idx = 1; idx < length(); idx++) {
1604     u2 tag = tag_at(idx).value();
1605     size += cpool_entry_size(idx);
1606 
1607     switch(tag) {
1608       case JVM_CONSTANT_Utf8: {
1609         Symbol* sym = symbol_at(idx);
1610         symmap->add_entry(sym, idx);
1611         DBG(printf("adding symbol entry %s = %d\n", sym->as_utf8(), idx));
1612         break;
1613       }
1614       case JVM_CONSTANT_Class:
1615       case JVM_CONSTANT_UnresolvedClass:
1616       case JVM_CONSTANT_UnresolvedClassInError: {
1617         Symbol* sym = klass_name_at(idx);
1618         classmap->add_entry(sym, idx);
1619         DBG(printf("adding class entry %s = %d\n", sym->as_utf8(), idx));
1620         break;
1621       }
1622       case JVM_CONSTANT_Long:
1623       case JVM_CONSTANT_Double: {
1624         idx++; // Both Long and Double take two cpool slots
1625         break;
1626       }
1627     }
1628   }
1629   return size;
1630 } /* end hash_utf8_entries_to */
1631 
1632 
1633 // Copy cpool bytes.
1634 // Returns:
1635 //    0, in case of OutOfMemoryError
1636 //   -1, in case of internal error
1637 //  > 0, count of the raw cpool bytes that have been copied
1638 int ConstantPool::copy_cpool_bytes(int cpool_size,
1639                                    SymbolHashMap* tbl,
1640                                    unsigned char *bytes) {
1641   u2   idx1, idx2;
1642   jint size  = 0;
1643   jint cnt   = length();
1644   unsigned char *start_bytes = bytes;
1645 
1646   for (jint idx = 1; idx < cnt; idx++) {
1647     u1   tag      = tag_at(idx).value();
1648     jint ent_size = cpool_entry_size(idx);
1649 
1650     assert(size + ent_size <= cpool_size, "Size mismatch");
1651 
1652     *bytes = tag;
1653     DBG(printf("#%03hd tag=%03hd, ", idx, tag));
1654     switch(tag) {
1655       case JVM_CONSTANT_Invalid: {
1656         DBG(printf("JVM_CONSTANT_Invalid"));
1657         break;
1658       }
1659       case JVM_CONSTANT_Unicode: {
1660         assert(false, "Wrong constant pool tag: JVM_CONSTANT_Unicode");
1661         DBG(printf("JVM_CONSTANT_Unicode"));
1662         break;
1663       }
1664       case JVM_CONSTANT_Utf8: {
1665         Symbol* sym = symbol_at(idx);
1666         char*     str = sym->as_utf8();
1667         // Warning! It's crashing on x86 with len = sym->utf8_length()
1668         int       len = (int) strlen(str);
1669         Bytes::put_Java_u2((address) (bytes+1), (u2) len);
1670         for (int i = 0; i < len; i++) {
1671             bytes[3+i] = (u1) str[i];
1672         }
1673         DBG(printf("JVM_CONSTANT_Utf8: %s ", str));
1674         break;
1675       }
1676       case JVM_CONSTANT_Integer: {
1677         jint val = int_at(idx);
1678         Bytes::put_Java_u4((address) (bytes+1), *(u4*)&val);
1679         break;
1680       }
1681       case JVM_CONSTANT_Float: {
1682         jfloat val = float_at(idx);
1683         Bytes::put_Java_u4((address) (bytes+1), *(u4*)&val);
1684         break;
1685       }
1686       case JVM_CONSTANT_Long: {
1687         jlong val = long_at(idx);
1688         Bytes::put_Java_u8((address) (bytes+1), *(u8*)&val);
1689         idx++;             // Long takes two cpool slots
1690         break;
1691       }
1692       case JVM_CONSTANT_Double: {
1693         jdouble val = double_at(idx);
1694         Bytes::put_Java_u8((address) (bytes+1), *(u8*)&val);
1695         idx++;             // Double takes two cpool slots
1696         break;
1697       }
1698       case JVM_CONSTANT_Class:
1699       case JVM_CONSTANT_UnresolvedClass:
1700       case JVM_CONSTANT_UnresolvedClassInError: {
1701         *bytes = JVM_CONSTANT_Class;
1702         Symbol* sym = klass_name_at(idx);
1703         idx1 = tbl->symbol_to_value(sym);
1704         assert(idx1 != 0, "Have not found a hashtable entry");
1705         Bytes::put_Java_u2((address) (bytes+1), idx1);
1706         DBG(printf("JVM_CONSTANT_Class: idx=#%03hd, %s", idx1, sym->as_utf8()));
1707         break;
1708       }
1709       case JVM_CONSTANT_String: {
1710         *bytes = JVM_CONSTANT_String;
1711         Symbol* sym = unresolved_string_at(idx);
1712         if (is_pseudo_string_at(idx)) {
1713           idx1 = get_pseudo_string_utf8_index(idx);
1714           assert(idx1 != 0, "Have not found a pseudo-string placeholder entry");
1715         } else {
1716           idx1 = tbl->symbol_to_value(sym);
1717           assert(idx1 != 0, "Have not found a hashtable entry");
1718         }
1719         Bytes::put_Java_u2((address) (bytes+1), idx1);
1720         DBG(printf("JVM_CONSTANT_String: idx=#%03hd, %s", idx1, sym == NULL ? "NULL" : sym->as_utf8()));
1721         break;
1722       }
1723       case JVM_CONSTANT_Fieldref:
1724       case JVM_CONSTANT_Methodref:
1725       case JVM_CONSTANT_InterfaceMethodref: {
1726         idx1 = uncached_klass_ref_index_at(idx);
1727         idx2 = uncached_name_and_type_ref_index_at(idx);
1728         Bytes::put_Java_u2((address) (bytes+1), idx1);
1729         Bytes::put_Java_u2((address) (bytes+3), idx2);
1730         DBG(printf("JVM_CONSTANT_Methodref: %hd %hd", idx1, idx2));
1731         break;
1732       }
1733       case JVM_CONSTANT_NameAndType: {
1734         idx1 = name_ref_index_at(idx);
1735         idx2 = signature_ref_index_at(idx);
1736         Bytes::put_Java_u2((address) (bytes+1), idx1);
1737         Bytes::put_Java_u2((address) (bytes+3), idx2);
1738         DBG(printf("JVM_CONSTANT_NameAndType: %hd %hd", idx1, idx2));
1739         break;
1740       }
1741       case JVM_CONSTANT_ClassIndex: {
1742         *bytes = JVM_CONSTANT_Class;
1743         idx1 = klass_index_at(idx);
1744         Bytes::put_Java_u2((address) (bytes+1), idx1);
1745         DBG(printf("JVM_CONSTANT_ClassIndex: %hd", idx1));
1746         break;
1747       }
1748       case JVM_CONSTANT_StringIndex: {
1749         *bytes = JVM_CONSTANT_String;
1750         idx1 = string_index_at(idx);
1751         Bytes::put_Java_u2((address) (bytes+1), idx1);
1752         DBG(printf("JVM_CONSTANT_StringIndex: %hd", idx1));
1753         break;
1754       }
1755       case JVM_CONSTANT_MethodHandle:
1756       case JVM_CONSTANT_MethodHandleInError: {
1757         *bytes = JVM_CONSTANT_MethodHandle;
1758         int kind = method_handle_ref_kind_at_error_ok(idx);
1759         idx1 = method_handle_index_at_error_ok(idx);
1760         *(bytes+1) = (unsigned char) kind;
1761         Bytes::put_Java_u2((address) (bytes+2), idx1);
1762         DBG(printf("JVM_CONSTANT_MethodHandle: %d %hd", kind, idx1));
1763         break;
1764       }
1765       case JVM_CONSTANT_MethodType:
1766       case JVM_CONSTANT_MethodTypeInError: {
1767         *bytes = JVM_CONSTANT_MethodType;
1768         idx1 = method_type_index_at_error_ok(idx);
1769         Bytes::put_Java_u2((address) (bytes+1), idx1);
1770         DBG(printf("JVM_CONSTANT_MethodType: %hd", idx1));
1771         break;
1772       }
1773       case JVM_CONSTANT_InvokeDynamic: {
1774         *bytes = tag;
1775         idx1 = extract_low_short_from_int(*int_at_addr(idx));
1776         idx2 = extract_high_short_from_int(*int_at_addr(idx));
1777         assert(idx2 == invoke_dynamic_name_and_type_ref_index_at(idx), "correct half of u4");
1778         Bytes::put_Java_u2((address) (bytes+1), idx1);
1779         Bytes::put_Java_u2((address) (bytes+3), idx2);
1780         DBG(printf("JVM_CONSTANT_InvokeDynamic: %hd %hd", idx1, idx2));
1781         break;
1782       }
1783     }
1784     DBG(printf("\n"));
1785     bytes += ent_size;
1786     size  += ent_size;
1787   }
1788   assert(size == cpool_size, "Size mismatch");
1789 
1790   // Keep temorarily for debugging until it's stable.
1791   DBG(print_cpool_bytes(cnt, start_bytes));
1792   return (int)(bytes - start_bytes);
1793 } /* end copy_cpool_bytes */
1794 
1795 #undef DBG
1796 
1797 
1798 void ConstantPool::set_on_stack(const bool value) {
1799   if (value) {
1800     int old_flags = *const_cast<volatile int *>(&_flags);
1801     while ((old_flags & _on_stack) == 0) {
1802       int new_flags = old_flags | _on_stack;
1803       int result = Atomic::cmpxchg(new_flags, &_flags, old_flags);
1804 
1805       if (result == old_flags) {
1806         // Succeeded.
1807         MetadataOnStackMark::record(this, Thread::current());
1808         return;
1809       }
1810       old_flags = result;
1811     }
1812   } else {
1813     // Clearing is done single-threadedly.
1814     _flags &= ~_on_stack;
1815   }
1816 }
1817 
1818 // JSR 292 support for patching constant pool oops after the class is linked and
1819 // the oop array for resolved references are created.
1820 // We can't do this during classfile parsing, which is how the other indexes are
1821 // patched.  The other patches are applied early for some error checking
1822 // so only defer the pseudo_strings.
1823 void ConstantPool::patch_resolved_references(GrowableArray<Handle>* cp_patches) {
1824   for (int index = 1; index < cp_patches->length(); index++) { // Index 0 is unused
1825     Handle patch = cp_patches->at(index);
1826     if (patch.not_null()) {
1827       assert (tag_at(index).is_string(), "should only be string left");
1828       // Patching a string means pre-resolving it.
1829       // The spelling in the constant pool is ignored.
1830       // The constant reference may be any object whatever.
1831       // If it is not a real interned string, the constant is referred
1832       // to as a "pseudo-string", and must be presented to the CP
1833       // explicitly, because it may require scavenging.
1834       int obj_index = cp_to_object_index(index);
1835       pseudo_string_at_put(index, obj_index, patch());
1836       DEBUG_ONLY(cp_patches->at_put(index, Handle());)
1837     }
1838   }
1839 #ifdef ASSERT
1840   // Ensure that all the patches have been used.
1841   for (int index = 0; index < cp_patches->length(); index++) {
1842     assert(cp_patches->at(index).is_null(),
1843            err_msg("Unused constant pool patch at %d in class file %s",
1844                    index,
1845                    pool_holder()->external_name()));
1846   }
1847 #endif // ASSERT
1848 }
1849 
1850 #ifndef PRODUCT
1851 
1852 // CompileTheWorld support. Preload all classes loaded references in the passed in constantpool
1853 void ConstantPool::preload_and_initialize_all_classes(ConstantPool* obj, TRAPS) {
1854   guarantee(obj->is_constantPool(), "object must be constant pool");
1855   constantPoolHandle cp(THREAD, (ConstantPool*)obj);
1856   guarantee(cp->pool_holder() != NULL, "must be fully loaded");
1857 
1858   for (int i = 0; i< cp->length();  i++) {
1859     if (cp->tag_at(i).is_unresolved_klass()) {
1860       // This will force loading of the class
1861       Klass* klass = cp->klass_at(i, CHECK);
1862       if (klass->oop_is_instance()) {
1863         // Force initialization of class
1864         InstanceKlass::cast(klass)->initialize(CHECK);
1865       }
1866     }
1867   }
1868 }
1869 
1870 #endif
1871 
1872 
1873 // Printing
1874 
1875 void ConstantPool::print_on(outputStream* st) const {
1876   assert(is_constantPool(), "must be constantPool");
1877   st->print_cr("%s", internal_name());
1878   if (flags() != 0) {
1879     st->print(" - flags: 0x%x", flags());
1880     if (has_preresolution()) st->print(" has_preresolution");
1881     if (on_stack()) st->print(" on_stack");
1882     st->cr();
1883   }
1884   if (pool_holder() != NULL) {
1885     st->print_cr(" - holder: " INTPTR_FORMAT, pool_holder());
1886   }
1887   st->print_cr(" - cache: " INTPTR_FORMAT, cache());
1888   st->print_cr(" - resolved_references: " INTPTR_FORMAT, (void *)resolved_references());
1889   st->print_cr(" - reference_map: " INTPTR_FORMAT, reference_map());
1890 
1891   for (int index = 1; index < length(); index++) {      // Index 0 is unused
1892     ((ConstantPool*)this)->print_entry_on(index, st);
1893     switch (tag_at(index).value()) {
1894       case JVM_CONSTANT_Long :
1895       case JVM_CONSTANT_Double :
1896         index++;   // Skip entry following eigth-byte constant
1897     }
1898 
1899   }
1900   st->cr();
1901 }
1902 
1903 // Print one constant pool entry
1904 void ConstantPool::print_entry_on(const int index, outputStream* st) {
1905   EXCEPTION_MARK;
1906   st->print(" - %3d : ", index);
1907   tag_at(index).print_on(st);
1908   st->print(" : ");
1909   switch (tag_at(index).value()) {
1910     case JVM_CONSTANT_Class :
1911       { Klass* k = klass_at(index, CATCH);
1912         guarantee(k != NULL, "need klass");
1913         k->print_value_on(st);
1914         st->print(" {0x%lx}", (address)k);
1915       }
1916       break;
1917     case JVM_CONSTANT_Fieldref :
1918     case JVM_CONSTANT_Methodref :
1919     case JVM_CONSTANT_InterfaceMethodref :
1920       st->print("klass_index=%d", uncached_klass_ref_index_at(index));
1921       st->print(" name_and_type_index=%d", uncached_name_and_type_ref_index_at(index));
1922       break;
1923     case JVM_CONSTANT_String :
1924       if (is_pseudo_string_at(index)) {
1925         oop anObj = pseudo_string_at(index);
1926         anObj->print_value_on(st);
1927         st->print(" {0x%lx}", (address)anObj);
1928       } else {
1929         unresolved_string_at(index)->print_value_on(st);
1930       }
1931       break;
1932     case JVM_CONSTANT_Integer :
1933       st->print("%d", int_at(index));
1934       break;
1935     case JVM_CONSTANT_Float :
1936       st->print("%f", float_at(index));
1937       break;
1938     case JVM_CONSTANT_Long :
1939       st->print_jlong(long_at(index));
1940       break;
1941     case JVM_CONSTANT_Double :
1942       st->print("%lf", double_at(index));
1943       break;
1944     case JVM_CONSTANT_NameAndType :
1945       st->print("name_index=%d", name_ref_index_at(index));
1946       st->print(" signature_index=%d", signature_ref_index_at(index));
1947       break;
1948     case JVM_CONSTANT_Utf8 :
1949       symbol_at(index)->print_value_on(st);
1950       break;
1951     case JVM_CONSTANT_UnresolvedClass :               // fall-through
1952     case JVM_CONSTANT_UnresolvedClassInError: {
1953       CPSlot entry = slot_at(index);
1954       if (entry.is_resolved()) {
1955         entry.get_klass()->print_value_on(st);
1956       } else {
1957         entry.get_symbol()->print_value_on(st);
1958       }
1959       }
1960       break;
1961     case JVM_CONSTANT_MethodHandle :
1962     case JVM_CONSTANT_MethodHandleInError :
1963       st->print("ref_kind=%d", method_handle_ref_kind_at_error_ok(index));
1964       st->print(" ref_index=%d", method_handle_index_at_error_ok(index));
1965       break;
1966     case JVM_CONSTANT_MethodType :
1967     case JVM_CONSTANT_MethodTypeInError :
1968       st->print("signature_index=%d", method_type_index_at_error_ok(index));
1969       break;
1970     case JVM_CONSTANT_InvokeDynamic :
1971       {
1972         st->print("bootstrap_method_index=%d", invoke_dynamic_bootstrap_method_ref_index_at(index));
1973         st->print(" name_and_type_index=%d", invoke_dynamic_name_and_type_ref_index_at(index));
1974         int argc = invoke_dynamic_argument_count_at(index);
1975         if (argc > 0) {
1976           for (int arg_i = 0; arg_i < argc; arg_i++) {
1977             int arg = invoke_dynamic_argument_index_at(index, arg_i);
1978             st->print((arg_i == 0 ? " arguments={%d" : ", %d"), arg);
1979           }
1980           st->print("}");
1981         }
1982       }
1983       break;
1984     default:
1985       ShouldNotReachHere();
1986       break;
1987   }
1988   st->cr();
1989 }
1990 
1991 void ConstantPool::print_value_on(outputStream* st) const {
1992   assert(is_constantPool(), "must be constantPool");
1993   st->print("constant pool [%d]", length());
1994   if (has_preresolution()) st->print("/preresolution");
1995   if (operands() != NULL)  st->print("/operands[%d]", operands()->length());
1996   print_address_on(st);
1997   st->print(" for ");
1998   pool_holder()->print_value_on(st);
1999   if (pool_holder() != NULL) {
2000     bool extra = (pool_holder()->constants() != this);
2001     if (extra)  st->print(" (extra)");
2002   }
2003   if (cache() != NULL) {
2004     st->print(" cache=" PTR_FORMAT, cache());
2005   }
2006 }
2007 
2008 #if INCLUDE_SERVICES
2009 // Size Statistics
2010 void ConstantPool::collect_statistics(KlassSizeStats *sz) const {
2011   sz->_cp_all_bytes += (sz->_cp_bytes          = sz->count(this));
2012   sz->_cp_all_bytes += (sz->_cp_tags_bytes     = sz->count_array(tags()));
2013   sz->_cp_all_bytes += (sz->_cp_cache_bytes    = sz->count(cache()));
2014   sz->_cp_all_bytes += (sz->_cp_operands_bytes = sz->count_array(operands()));
2015   sz->_cp_all_bytes += (sz->_cp_refmap_bytes   = sz->count_array(reference_map()));
2016 
2017   sz->_ro_bytes += sz->_cp_operands_bytes + sz->_cp_tags_bytes +
2018                    sz->_cp_refmap_bytes;
2019   sz->_rw_bytes += sz->_cp_bytes + sz->_cp_cache_bytes;
2020 }
2021 #endif // INCLUDE_SERVICES
2022 
2023 // Verification
2024 
2025 void ConstantPool::verify_on(outputStream* st) {
2026   guarantee(is_constantPool(), "object must be constant pool");
2027   for (int i = 0; i< length();  i++) {
2028     constantTag tag = tag_at(i);
2029     CPSlot entry = slot_at(i);
2030     if (tag.is_klass()) {
2031       if (entry.is_resolved()) {
2032         guarantee(entry.get_klass()->is_klass(),    "should be klass");
2033       }
2034     } else if (tag.is_unresolved_klass()) {
2035       if (entry.is_resolved()) {
2036         guarantee(entry.get_klass()->is_klass(),    "should be klass");
2037       }
2038     } else if (tag.is_symbol()) {
2039       guarantee(entry.get_symbol()->refcount() != 0, "should have nonzero reference count");
2040     } else if (tag.is_string()) {
2041       guarantee(entry.get_symbol()->refcount() != 0, "should have nonzero reference count");
2042     }
2043   }
2044   if (cache() != NULL) {
2045     // Note: cache() can be NULL before a class is completely setup or
2046     // in temporary constant pools used during constant pool merging
2047     guarantee(cache()->is_constantPoolCache(), "should be constant pool cache");
2048   }
2049   if (pool_holder() != NULL) {
2050     // Note: pool_holder() can be NULL in temporary constant pools
2051     // used during constant pool merging
2052     guarantee(pool_holder()->is_klass(),    "should be klass");
2053   }
2054 }
2055 
2056 
2057 void SymbolHashMap::add_entry(Symbol* sym, u2 value) {
2058   char *str = sym->as_utf8();
2059   unsigned int hash = compute_hash(str, sym->utf8_length());
2060   unsigned int index = hash % table_size();
2061 
2062   // check if already in map
2063   // we prefer the first entry since it is more likely to be what was used in
2064   // the class file
2065   for (SymbolHashMapEntry *en = bucket(index); en != NULL; en = en->next()) {
2066     assert(en->symbol() != NULL, "SymbolHashMapEntry symbol is NULL");
2067     if (en->hash() == hash && en->symbol() == sym) {
2068         return;  // already there
2069     }
2070   }
2071 
2072   SymbolHashMapEntry* entry = new SymbolHashMapEntry(hash, sym, value);
2073   entry->set_next(bucket(index));
2074   _buckets[index].set_entry(entry);
2075   assert(entry->symbol() != NULL, "SymbolHashMapEntry symbol is NULL");
2076 }
2077 
2078 SymbolHashMapEntry* SymbolHashMap::find_entry(Symbol* sym) {
2079   assert(sym != NULL, "SymbolHashMap::find_entry - symbol is NULL");
2080   char *str = sym->as_utf8();
2081   int   len = sym->utf8_length();
2082   unsigned int hash = SymbolHashMap::compute_hash(str, len);
2083   unsigned int index = hash % table_size();
2084   for (SymbolHashMapEntry *en = bucket(index); en != NULL; en = en->next()) {
2085     assert(en->symbol() != NULL, "SymbolHashMapEntry symbol is NULL");
2086     if (en->hash() == hash && en->symbol() == sym) {
2087       return en;
2088     }
2089   }
2090   return NULL;
2091 }