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