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