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