1 /*
   2  * Copyright (c) 1997, 2025, 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 #ifndef SHARE_OOPS_INSTANCEKLASS_HPP
  26 #define SHARE_OOPS_INSTANCEKLASS_HPP
  27 
  28 #include "memory/allocation.hpp"
  29 #include "memory/referenceType.hpp"
  30 #include "oops/annotations.hpp"
  31 #include "oops/constMethod.hpp"
  32 #include "oops/fieldInfo.hpp"
  33 #include "oops/instanceKlassFlags.hpp"
  34 #include "oops/instanceOop.hpp"
  35 #include "runtime/handles.hpp"
  36 #include "runtime/javaThread.hpp"
  37 #include "utilities/accessFlags.hpp"
  38 #include "utilities/align.hpp"
  39 #include "utilities/growableArray.hpp"
  40 #include "utilities/macros.hpp"
  41 #if INCLUDE_JFR
  42 #include "jfr/support/jfrKlassExtension.hpp"
  43 #endif
  44 
  45 class ConstantPool;
  46 class DeoptimizationScope;
  47 class klassItable;
  48 class RecordComponent;
  49 
  50 // An InstanceKlass is the VM level representation of a Java class.
  51 // It contains all information needed for at class at execution runtime.
  52 
  53 //  InstanceKlass embedded field layout (after declared fields):
  54 //    [EMBEDDED Java vtable             ] size in words = vtable_len
  55 //    [EMBEDDED nonstatic oop-map blocks] size in words = nonstatic_oop_map_size
  56 //      The embedded nonstatic oop-map blocks are short pairs (offset, length)
  57 //      indicating where oops are located in instances of this klass.
  58 //    [EMBEDDED implementor of the interface] only exist for interface
  59 
  60 
  61 // forward declaration for class -- see below for definition
  62 #if INCLUDE_JVMTI
  63 class BreakpointInfo;
  64 #endif
  65 class ClassFileParser;
  66 class ClassFileStream;
  67 class KlassDepChange;
  68 class DependencyContext;
  69 class fieldDescriptor;
  70 class JNIid;
  71 class JvmtiCachedClassFieldMap;
  72 class nmethodBucket;
  73 class OopMapCache;
  74 class InterpreterOopMap;
  75 class PackageEntry;
  76 class ModuleEntry;
  77 
  78 // This is used in iterators below.
  79 class FieldClosure: public StackObj {
  80 public:
  81   virtual void do_field(fieldDescriptor* fd) = 0;
  82 };
  83 
  84 // Print fields.
  85 // If "obj" argument to constructor is null, prints static fields, otherwise prints non-static fields.
  86 class FieldPrinter: public FieldClosure {
  87    oop _obj;
  88    outputStream* _st;
  89  public:
  90    FieldPrinter(outputStream* st, oop obj = nullptr) : _obj(obj), _st(st) {}
  91    void do_field(fieldDescriptor* fd);
  92 };
  93 
  94 // Describes where oops are located in instances of this klass.
  95 class OopMapBlock {
  96  public:
  97   // Byte offset of the first oop mapped by this block.
  98   int offset() const          { return _offset; }
  99   void set_offset(int offset) { _offset = offset; }
 100 
 101   // Number of oops in this block.
 102   uint count() const         { return _count; }
 103   void set_count(uint count) { _count = count; }
 104 
 105   void increment_count(int diff) { _count += diff; }
 106 
 107   int offset_span() const { return _count * heapOopSize; }
 108 
 109   int end_offset() const {
 110     return offset() + offset_span();
 111   }
 112 
 113   bool is_contiguous(int another_offset) const {
 114     return another_offset == end_offset();
 115   }
 116 
 117   // sizeof(OopMapBlock) in words.
 118   static int size_in_words() {
 119     return align_up((int)sizeof(OopMapBlock), wordSize) >>
 120       LogBytesPerWord;
 121   }
 122 
 123   static int compare_offset(const OopMapBlock* a, const OopMapBlock* b) {
 124     return a->offset() - b->offset();
 125   }
 126 
 127  private:
 128   int  _offset;
 129   uint _count;
 130 };
 131 
 132 struct JvmtiCachedClassFileData;
 133 
 134 class InstanceKlass: public Klass {
 135   friend class VMStructs;
 136   friend class JVMCIVMStructs;
 137   friend class ClassFileParser;
 138   friend class CompileReplay;
 139 
 140  public:
 141   static const KlassKind Kind = InstanceKlassKind;
 142 
 143  protected:
 144   InstanceKlass(const ClassFileParser& parser, KlassKind kind = Kind, ReferenceType reference_type = REF_NONE);
 145 
 146   void* operator new(size_t size, ClassLoaderData* loader_data, size_t word_size, bool use_class_space, TRAPS) throw();
 147 
 148  public:
 149   InstanceKlass();
 150 
 151   // See "The Java Virtual Machine Specification" section 2.16.2-5 for a detailed description
 152   // of the class loading & initialization procedure, and the use of the states.
 153   enum ClassState : u1 {
 154     allocated,                          // allocated (but not yet linked)
 155     loaded,                             // loaded and inserted in class hierarchy (but not linked yet)
 156     linked,                             // successfully linked/verified (but not initialized yet)
 157     being_initialized,                  // currently running class initializer
 158     fully_initialized,                  // initialized (successful final state)
 159     initialization_error                // error happened during initialization
 160   };
 161 
 162  private:
 163   static InstanceKlass* allocate_instance_klass(const ClassFileParser& parser, TRAPS);
 164 
 165  protected:
 166   // If you add a new field that points to any metaspace object, you
 167   // must add this field to InstanceKlass::metaspace_pointers_do().
 168 
 169   // Annotations for this class
 170   Annotations*    _annotations;
 171   // Package this class is defined in
 172   PackageEntry*   _package_entry;
 173   // Array classes holding elements of this class.
 174   ObjArrayKlass* volatile _array_klasses;
 175   // Constant pool for this class.
 176   ConstantPool* _constants;
 177   // The InnerClasses attribute and EnclosingMethod attribute. The
 178   // _inner_classes is an array of shorts. If the class has InnerClasses
 179   // attribute, then the _inner_classes array begins with 4-tuples of shorts
 180   // [inner_class_info_index, outer_class_info_index,
 181   // inner_name_index, inner_class_access_flags] for the InnerClasses
 182   // attribute. If the EnclosingMethod attribute exists, it occupies the
 183   // last two shorts [class_index, method_index] of the array. If only
 184   // the InnerClasses attribute exists, the _inner_classes array length is
 185   // number_of_inner_classes * 4. If the class has both InnerClasses
 186   // and EnclosingMethod attributes the _inner_classes array length is
 187   // number_of_inner_classes * 4 + enclosing_method_attribute_size.
 188   Array<jushort>* _inner_classes;
 189 
 190   // The NestMembers attribute. An array of shorts, where each is a
 191   // class info index for the class that is a nest member. This data
 192   // has not been validated.
 193   Array<jushort>* _nest_members;
 194 
 195   // Resolved nest-host klass: either true nest-host or self if we are not
 196   // nested, or an error occurred resolving or validating the nominated
 197   // nest-host. Can also be set directly by JDK API's that establish nest
 198   // relationships.
 199   // By always being set it makes nest-member access checks simpler.
 200   InstanceKlass* _nest_host;
 201 
 202   // The PermittedSubclasses attribute. An array of shorts, where each is a
 203   // class info index for the class that is a permitted subclass.
 204   Array<jushort>* _permitted_subclasses;
 205 
 206   // The contents of the Record attribute.
 207   Array<RecordComponent*>* _record_components;
 208 
 209   // the source debug extension for this klass, null if not specified.
 210   // Specified as UTF-8 string without terminating zero byte in the classfile,
 211   // it is stored in the instanceklass as a null-terminated UTF-8 string
 212   const char*     _source_debug_extension;
 213 
 214   // Number of heapOopSize words used by non-static fields in this klass
 215   // (including inherited fields but after header_size()).
 216   int             _nonstatic_field_size;
 217   int             _static_field_size;       // number words used by static fields (oop and non-oop) in this klass
 218   int             _nonstatic_oop_map_size;  // size in words of nonstatic oop map blocks
 219   int             _itable_len;              // length of Java itable (in words)
 220 
 221   // The NestHost attribute. The class info index for the class
 222   // that is the nest-host of this class. This data has not been validated.
 223   u2              _nest_host_index;
 224   u2              _this_class_index;        // constant pool entry
 225   u2              _static_oop_field_count;  // number of static oop fields in this klass
 226 
 227   volatile u2     _idnum_allocated_count;   // JNI/JVMTI: increments with the addition of methods, old ids don't change
 228 
 229   // Class states are defined as ClassState (see above).
 230   // Place the _init_state here to utilize the unused 2-byte after
 231   // _idnum_allocated_count.
 232   volatile ClassState _init_state;          // state of class
 233 
 234   u1              _reference_type;                // reference type
 235 
 236   // State is set either at parse time or while executing, atomically to not disturb other state
 237   InstanceKlassFlags _misc_flags;
 238 
 239   JavaThread* volatile _init_thread;        // Pointer to current thread doing initialization (to handle recursive initialization)
 240 
 241   OopMapCache*    volatile _oop_map_cache;   // OopMapCache for all methods in the klass (allocated lazily)
 242   JNIid*          _jni_ids;                  // First JNI identifier for static fields in this class
 243   jmethodID* volatile _methods_jmethod_ids;  // jmethodIDs corresponding to method_idnum, or null if none
 244   nmethodBucket*  volatile _dep_context;     // packed DependencyContext structure
 245   uint64_t        volatile _dep_context_last_cleaned;
 246   nmethod*        _osr_nmethods_head;    // Head of list of on-stack replacement nmethods for this class
 247 #if INCLUDE_JVMTI
 248   BreakpointInfo* _breakpoints;          // bpt lists, managed by Method*
 249   // Linked instanceKlasses of previous versions
 250   InstanceKlass* _previous_versions;
 251   // JVMTI fields can be moved to their own structure - see 6315920
 252   // JVMTI: cached class file, before retransformable agent modified it in CFLH
 253   JvmtiCachedClassFileData* _cached_class_file;
 254 #endif
 255 
 256 #if INCLUDE_JVMTI
 257   JvmtiCachedClassFieldMap* _jvmti_cached_class_field_map;  // JVMTI: used during heap iteration
 258 #endif
 259 
 260   NOT_PRODUCT(int _verify_count;)  // to avoid redundant verifies
 261   NOT_PRODUCT(volatile int _shared_class_load_count;) // ensure a shared class is loaded only once
 262 
 263   // Method array.
 264   Array<Method*>* _methods;
 265   // Default Method Array, concrete methods inherited from interfaces
 266   Array<Method*>* _default_methods;
 267   // Interfaces (InstanceKlass*s) this class declares locally to implement.
 268   Array<InstanceKlass*>* _local_interfaces;
 269   // Interfaces (InstanceKlass*s) this class implements transitively.
 270   Array<InstanceKlass*>* _transitive_interfaces;
 271   // Int array containing the original order of method in the class file (for JVMTI).
 272   Array<int>*     _method_ordering;
 273   // Int array containing the vtable_indices for default_methods
 274   // offset matches _default_methods offset
 275   Array<int>*     _default_vtable_indices;
 276 
 277   // Fields information is stored in an UNSIGNED5 encoded stream (see fieldInfo.hpp)
 278   Array<u1>*          _fieldinfo_stream;
 279   Array<FieldStatus>* _fields_status;
 280 
 281   // embedded Java vtable follows here
 282   // embedded Java itables follows here
 283   // embedded static fields follows here
 284   // embedded nonstatic oop-map blocks follows here
 285   // embedded implementor of this interface follows here
 286   //   The embedded implementor only exists if the current klass is an
 287   //   interface. The possible values of the implementor fall into following
 288   //   three cases:
 289   //     null: no implementor.
 290   //     A Klass* that's not itself: one implementor.
 291   //     Itself: more than one implementors.
 292   //
 293 
 294   friend class SystemDictionary;
 295 
 296   static bool _disable_method_binary_search;
 297 
 298   // Controls finalizer registration
 299   static bool _finalization_enabled;
 300 
 301  public:
 302 
 303   // Queries finalization state
 304   static bool is_finalization_enabled() { return _finalization_enabled; }
 305 
 306   // Sets finalization state
 307   static void set_finalization_enabled(bool val) { _finalization_enabled = val; }
 308 
 309   // The three BUILTIN class loader types
 310   bool is_shared_boot_class() const { return _misc_flags.is_shared_boot_class(); }
 311   bool is_shared_platform_class() const { return _misc_flags.is_shared_platform_class(); }
 312   bool is_shared_app_class() const {  return _misc_flags.is_shared_app_class(); }
 313   // The UNREGISTERED class loader type
 314   bool is_shared_unregistered_class() const { return _misc_flags.is_shared_unregistered_class(); }
 315 
 316   // Check if the class can be shared in CDS
 317   bool is_shareable() const;
 318 
 319   bool shared_loading_failed() const { return _misc_flags.shared_loading_failed(); }
 320 
 321   void set_shared_loading_failed() { _misc_flags.set_shared_loading_failed(true); }
 322 
 323 #if INCLUDE_CDS
 324   int  shared_class_loader_type() const;
 325   void set_shared_class_loader_type(s2 loader_type) { _misc_flags.set_shared_class_loader_type(loader_type); }
 326   void assign_class_loader_type() { _misc_flags.assign_class_loader_type(_class_loader_data); }
 327 #endif
 328 
 329   bool has_nonstatic_fields() const        { return _misc_flags.has_nonstatic_fields(); }
 330   void set_has_nonstatic_fields(bool b)    { _misc_flags.set_has_nonstatic_fields(b); }
 331 
 332   bool has_localvariable_table() const     { return _misc_flags.has_localvariable_table(); }
 333   void set_has_localvariable_table(bool b) { _misc_flags.set_has_localvariable_table(b); }
 334 
 335   // field sizes
 336   int nonstatic_field_size() const         { return _nonstatic_field_size; }
 337   void set_nonstatic_field_size(int size)  { _nonstatic_field_size = size; }
 338 
 339   int static_field_size() const            { return _static_field_size; }
 340   void set_static_field_size(int size)     { _static_field_size = size; }
 341 
 342   int static_oop_field_count() const       { return (int)_static_oop_field_count; }
 343   void set_static_oop_field_count(u2 size) { _static_oop_field_count = size; }
 344 
 345   // Java itable
 346   int  itable_length() const               { return _itable_len; }
 347   void set_itable_length(int len)          { _itable_len = len; }
 348 
 349   // array klasses
 350   ObjArrayKlass* array_klasses() const     { return _array_klasses; }
 351   inline ObjArrayKlass* array_klasses_acquire() const; // load with acquire semantics
 352   inline void release_set_array_klasses(ObjArrayKlass* k); // store with release semantics
 353   void set_array_klasses(ObjArrayKlass* k) { _array_klasses = k; }
 354 
 355   // methods
 356   Array<Method*>* methods() const          { return _methods; }
 357   void set_methods(Array<Method*>* a)      { _methods = a; }
 358   Method* method_with_idnum(int idnum);
 359   Method* method_with_orig_idnum(int idnum);
 360   Method* method_with_orig_idnum(int idnum, int version);
 361 
 362   // method ordering
 363   Array<int>* method_ordering() const     { return _method_ordering; }
 364   void set_method_ordering(Array<int>* m) { _method_ordering = m; }
 365   void copy_method_ordering(const intArray* m, TRAPS);
 366 
 367   // default_methods
 368   Array<Method*>* default_methods() const  { return _default_methods; }
 369   void set_default_methods(Array<Method*>* a) { _default_methods = a; }
 370 
 371   // default method vtable_indices
 372   Array<int>* default_vtable_indices() const { return _default_vtable_indices; }
 373   void set_default_vtable_indices(Array<int>* v) { _default_vtable_indices = v; }
 374   Array<int>* create_new_default_vtable_indices(int len, TRAPS);
 375 
 376   // interfaces
 377   Array<InstanceKlass*>* local_interfaces() const          { return _local_interfaces; }
 378   void set_local_interfaces(Array<InstanceKlass*>* a)      {
 379     guarantee(_local_interfaces == nullptr || a == nullptr, "Just checking");
 380     _local_interfaces = a; }
 381 
 382   Array<InstanceKlass*>* transitive_interfaces() const     { return _transitive_interfaces; }
 383   void set_transitive_interfaces(Array<InstanceKlass*>* a) {
 384     guarantee(_transitive_interfaces == nullptr || a == nullptr, "Just checking");
 385     _transitive_interfaces = a;
 386   }
 387 
 388  private:
 389   friend class fieldDescriptor;
 390   FieldInfo field(int index) const;
 391 
 392  public:
 393   int     field_offset      (int index) const { return field(index).offset(); }
 394   int     field_access_flags(int index) const { return field(index).access_flags().as_field_flags(); }
 395   FieldInfo::FieldFlags field_flags(int index) const { return field(index).field_flags(); }
 396   FieldStatus field_status(int index)   const { return fields_status()->at(index); }
 397   inline Symbol* field_name        (int index) const;
 398   inline Symbol* field_signature   (int index) const;
 399 
 400   // Number of Java declared fields
 401   int java_fields_count() const;
 402   int total_fields_count() const;
 403 
 404   Array<u1>* fieldinfo_stream() const { return _fieldinfo_stream; }
 405   void set_fieldinfo_stream(Array<u1>* fis) { _fieldinfo_stream = fis; }
 406 
 407   Array<FieldStatus>* fields_status() const {return _fields_status; }
 408   void set_fields_status(Array<FieldStatus>* array) { _fields_status = array; }
 409 
 410   // inner classes
 411   Array<u2>* inner_classes() const       { return _inner_classes; }
 412   void set_inner_classes(Array<u2>* f)   { _inner_classes = f; }
 413 
 414   // nest members
 415   Array<u2>* nest_members() const     { return _nest_members; }
 416   void set_nest_members(Array<u2>* m) { _nest_members = m; }
 417 
 418   // nest-host index
 419   jushort nest_host_index() const { return _nest_host_index; }
 420   void set_nest_host_index(u2 i)  { _nest_host_index = i; }
 421   // dynamic nest member support
 422   void set_nest_host(InstanceKlass* host);
 423 
 424   // record components
 425   Array<RecordComponent*>* record_components() const { return _record_components; }
 426   void set_record_components(Array<RecordComponent*>* record_components) {
 427     _record_components = record_components;
 428   }
 429   bool is_record() const;
 430 
 431   // test for enum class (or possibly an anonymous subclass within a sealed enum)
 432   bool is_enum_subclass() const;
 433 
 434   // permitted subclasses
 435   Array<u2>* permitted_subclasses() const     { return _permitted_subclasses; }
 436   void set_permitted_subclasses(Array<u2>* s) { _permitted_subclasses = s; }
 437 
 438 private:
 439   // Called to verify that k is a member of this nest - does not look at k's nest-host,
 440   // nor does it resolve any CP entries or load any classes.
 441   bool has_nest_member(JavaThread* current, InstanceKlass* k) const;
 442 
 443 public:
 444   // Call this only if you know that the nest host has been initialized.
 445   InstanceKlass* nest_host_not_null() {
 446     assert(_nest_host != nullptr, "must be");
 447     return _nest_host;
 448   }
 449   // Used to construct informative IllegalAccessError messages at a higher level,
 450   // if there was an issue resolving or validating the nest host.
 451   // Returns null if there was no error.
 452   const char* nest_host_error();
 453   // Returns nest-host class, resolving and validating it if needed.
 454   // Returns null if resolution is not possible from the calling context.
 455   InstanceKlass* nest_host(TRAPS);
 456   // Check if this klass is a nestmate of k - resolves this nest-host and k's
 457   bool has_nestmate_access_to(InstanceKlass* k, TRAPS);
 458 
 459   // Called to verify that k is a permitted subclass of this class.
 460   // The incoming stringStream is used for logging, and for the caller to create
 461   // a detailed exception message on failure.
 462   bool has_as_permitted_subclass(const InstanceKlass* k, stringStream& ss) const;
 463 
 464   enum InnerClassAttributeOffset {
 465     // From http://mirror.eng/products/jdk/1.1/docs/guide/innerclasses/spec/innerclasses.doc10.html#18814
 466     inner_class_inner_class_info_offset = 0,
 467     inner_class_outer_class_info_offset = 1,
 468     inner_class_inner_name_offset = 2,
 469     inner_class_access_flags_offset = 3,
 470     inner_class_next_offset = 4
 471   };
 472 
 473   enum EnclosingMethodAttributeOffset {
 474     enclosing_method_class_index_offset = 0,
 475     enclosing_method_method_index_offset = 1,
 476     enclosing_method_attribute_size = 2
 477   };
 478 
 479   // package
 480   PackageEntry* package() const     { return _package_entry; }
 481   ModuleEntry* module() const;
 482   bool in_javabase_module() const;
 483   bool in_unnamed_package() const   { return (_package_entry == nullptr); }
 484   void set_package(ClassLoaderData* loader_data, PackageEntry* pkg_entry, TRAPS);
 485   // If the package for the InstanceKlass is in the boot loader's package entry
 486   // table then sets the classpath_index field so that
 487   // get_system_package() will know to return a non-null value for the
 488   // package's location.  And, so that the package will be added to the list of
 489   // packages returned by get_system_packages().
 490   // For packages whose classes are loaded from the boot loader class path, the
 491   // classpath_index indicates which entry on the boot loader class path.
 492   void set_classpath_index(s2 path_index);
 493   bool is_same_class_package(const Klass* class2) const;
 494   bool is_same_class_package(oop other_class_loader, const Symbol* other_class_name) const;
 495 
 496   // find an enclosing class
 497   InstanceKlass* compute_enclosing_class(bool* inner_is_member, TRAPS) const;
 498 
 499   // Find InnerClasses attribute and return outer_class_info_index & inner_name_index.
 500   bool find_inner_classes_attr(int* ooff, int* noff, TRAPS) const;
 501 
 502  private:
 503   // Check prohibited package ("java/" only loadable by boot or platform loaders)
 504   static void check_prohibited_package(Symbol* class_name,
 505                                        ClassLoaderData* loader_data,
 506                                        TRAPS);
 507 
 508   JavaThread* init_thread()  { return Atomic::load(&_init_thread); }
 509   const char* init_thread_name() {
 510     return init_thread()->name_raw();
 511   }
 512 
 513  public:
 514   // initialization state
 515   bool is_loaded() const                   { return init_state() >= loaded; }
 516   bool is_linked() const                   { return init_state() >= linked; }
 517   bool is_initialized() const              { return init_state() == fully_initialized; }
 518   bool is_not_initialized() const          { return init_state() <  being_initialized; }
 519   bool is_being_initialized() const        { return init_state() == being_initialized; }
 520   bool is_in_error_state() const           { return init_state() == initialization_error; }
 521   bool is_reentrant_initialization(Thread *thread)  { return thread == _init_thread; }
 522   ClassState  init_state() const           { return Atomic::load_acquire(&_init_state); }
 523   const char* init_state_name() const;
 524   bool is_rewritten() const                { return _misc_flags.rewritten(); }
 525 
 526   static const char* state2name(ClassState state);
 527 
 528   // is this a sealed class
 529   bool is_sealed() const;
 530 
 531   // defineClass specified verification
 532   bool should_verify_class() const         { return _misc_flags.should_verify_class(); }
 533   void set_should_verify_class(bool value) { _misc_flags.set_should_verify_class(value); }
 534 
 535   // marking
 536   bool is_marked_dependent() const         { return _misc_flags.is_marked_dependent(); }
 537   void set_is_marked_dependent(bool value) { _misc_flags.set_is_marked_dependent(value); }
 538 
 539   // initialization (virtuals from Klass)
 540   bool should_be_initialized() const;  // means that initialize should be called
 541   void initialize_with_aot_initialized_mirror(TRAPS);
 542   void assert_no_clinit_will_run_for_aot_initialized_class() const NOT_DEBUG_RETURN;
 543   void initialize(TRAPS);
 544   void link_class(TRAPS);
 545   bool link_class_or_fail(TRAPS); // returns false on failure
 546   void rewrite_class(TRAPS);
 547   void link_methods(TRAPS);
 548   Method* class_initializer() const;
 549   bool interface_needs_clinit_execution_as_super(bool also_check_supers=true) const;
 550 
 551   // reference type
 552   ReferenceType reference_type() const     { return (ReferenceType)_reference_type; }
 553 
 554   // this class cp index
 555   u2 this_class_index() const             { return _this_class_index; }
 556   void set_this_class_index(u2 index)     { _this_class_index = index; }
 557 
 558   static ByteSize reference_type_offset() { return byte_offset_of(InstanceKlass, _reference_type); }
 559 
 560   // find local field, returns true if found
 561   bool find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
 562   // find field in direct superinterfaces, returns the interface in which the field is defined
 563   Klass* find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
 564   // find field according to JVM spec 5.4.3.2, returns the klass in which the field is defined
 565   Klass* find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
 566   // find instance or static fields according to JVM spec 5.4.3.2, returns the klass in which the field is defined
 567   Klass* find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const;
 568 
 569   // find a non-static or static field given its offset within the class.
 570   bool contains_field_offset(int offset);
 571 
 572   bool find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const;
 573   bool find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const;
 574 
 575  private:
 576   inline static int quick_search(const Array<Method*>* methods, const Symbol* name);
 577 
 578  public:
 579   static void disable_method_binary_search() {
 580     _disable_method_binary_search = true;
 581   }
 582 
 583   // find a local method (returns null if not found)
 584   Method* find_method(const Symbol* name, const Symbol* signature) const;
 585   static Method* find_method(const Array<Method*>* methods,
 586                              const Symbol* name,
 587                              const Symbol* signature);
 588 
 589   // find a local method, but skip static methods
 590   Method* find_instance_method(const Symbol* name, const Symbol* signature,
 591                                PrivateLookupMode private_mode) const;
 592   static Method* find_instance_method(const Array<Method*>* methods,
 593                                       const Symbol* name,
 594                                       const Symbol* signature,
 595                                       PrivateLookupMode private_mode);
 596 
 597   // find a local method (returns null if not found)
 598   Method* find_local_method(const Symbol* name,
 599                             const Symbol* signature,
 600                             OverpassLookupMode overpass_mode,
 601                             StaticLookupMode static_mode,
 602                             PrivateLookupMode private_mode) const;
 603 
 604   // find a local method from given methods array (returns null if not found)
 605   static Method* find_local_method(const Array<Method*>* methods,
 606                                    const Symbol* name,
 607                                    const Symbol* signature,
 608                                    OverpassLookupMode overpass_mode,
 609                                    StaticLookupMode static_mode,
 610                                    PrivateLookupMode private_mode);
 611 
 612   // find a local method index in methods or default_methods (returns -1 if not found)
 613   static int find_method_index(const Array<Method*>* methods,
 614                                const Symbol* name,
 615                                const Symbol* signature,
 616                                OverpassLookupMode overpass_mode,
 617                                StaticLookupMode static_mode,
 618                                PrivateLookupMode private_mode);
 619 
 620   // lookup operation (returns null if not found)
 621   Method* uncached_lookup_method(const Symbol* name,
 622                                  const Symbol* signature,
 623                                  OverpassLookupMode overpass_mode,
 624                                  PrivateLookupMode private_mode = PrivateLookupMode::find) const;
 625 
 626   // lookup a method in all the interfaces that this class implements
 627   // (returns null if not found)
 628   Method* lookup_method_in_all_interfaces(Symbol* name, Symbol* signature, DefaultsLookupMode defaults_mode) const;
 629 
 630   // lookup a method in local defaults then in all interfaces
 631   // (returns null if not found)
 632   Method* lookup_method_in_ordered_interfaces(Symbol* name, Symbol* signature) const;
 633 
 634   // Find method indices by name.  If a method with the specified name is
 635   // found the index to the first method is returned, and 'end' is filled in
 636   // with the index of first non-name-matching method.  If no method is found
 637   // -1 is returned.
 638   int find_method_by_name(const Symbol* name, int* end) const;
 639   static int find_method_by_name(const Array<Method*>* methods,
 640                                  const Symbol* name, int* end);
 641 
 642   // constant pool
 643   ConstantPool* constants() const        { return _constants; }
 644   void set_constants(ConstantPool* c)    { _constants = c; }
 645 
 646   // protection domain
 647   oop protection_domain() const;
 648 
 649   // signers
 650   objArrayOop signers() const;
 651 
 652   bool is_contended() const                { return _misc_flags.is_contended(); }
 653   void set_is_contended(bool value)        { _misc_flags.set_is_contended(value); }
 654 
 655   // source file name
 656   Symbol* source_file_name() const;
 657   u2 source_file_name_index() const;
 658   void set_source_file_name_index(u2 sourcefile_index);
 659 
 660   // minor and major version numbers of class file
 661   u2 minor_version() const;
 662   void set_minor_version(u2 minor_version);
 663   u2 major_version() const;
 664   void set_major_version(u2 major_version);
 665 
 666   // source debug extension
 667   const char* source_debug_extension() const { return _source_debug_extension; }
 668   void set_source_debug_extension(const char* array, int length);
 669 
 670   // nonstatic oop-map blocks
 671   static int nonstatic_oop_map_size(unsigned int oop_map_count) {
 672     return oop_map_count * OopMapBlock::size_in_words();
 673   }
 674   unsigned int nonstatic_oop_map_count() const {
 675     return _nonstatic_oop_map_size / OopMapBlock::size_in_words();
 676   }
 677   int nonstatic_oop_map_size() const { return _nonstatic_oop_map_size; }
 678   void set_nonstatic_oop_map_size(int words) {
 679     _nonstatic_oop_map_size = words;
 680   }
 681 
 682   bool has_contended_annotations() const { return _misc_flags.has_contended_annotations(); }
 683   void set_has_contended_annotations(bool value)  { _misc_flags.set_has_contended_annotations(value); }
 684 
 685 #if INCLUDE_JVMTI
 686   // Redefinition locking.  Class can only be redefined by one thread at a time.
 687   bool is_being_redefined() const          { return _misc_flags.is_being_redefined(); }
 688   void set_is_being_redefined(bool value)  { _misc_flags.set_is_being_redefined(value); }
 689 
 690   // RedefineClasses() support for previous versions:
 691   void add_previous_version(InstanceKlass* ik, int emcp_method_count);
 692   void purge_previous_version_list();
 693 
 694   InstanceKlass* previous_versions() const { return _previous_versions; }
 695 #else
 696   InstanceKlass* previous_versions() const { return nullptr; }
 697 #endif
 698 
 699   InstanceKlass* get_klass_version(int version);
 700 
 701   bool has_been_redefined() const { return _misc_flags.has_been_redefined(); }
 702   void set_has_been_redefined() { _misc_flags.set_has_been_redefined(true); }
 703 
 704   bool is_scratch_class() const { return _misc_flags.is_scratch_class(); }
 705   void set_is_scratch_class() { _misc_flags.set_is_scratch_class(true); }
 706 
 707   bool has_resolved_methods() const { return _misc_flags.has_resolved_methods(); }
 708   void set_has_resolved_methods()   { _misc_flags.set_has_resolved_methods(true); }
 709   void set_has_resolved_methods(bool value)   { _misc_flags.set_has_resolved_methods(value); }
 710 
 711 public:
 712 #if INCLUDE_JVMTI
 713 
 714   void init_previous_versions() {
 715     _previous_versions = nullptr;
 716   }
 717 
 718  private:
 719   static bool  _should_clean_previous_versions;
 720  public:
 721   static void purge_previous_versions(InstanceKlass* ik) {
 722     if (ik->has_been_redefined()) {
 723       ik->purge_previous_version_list();
 724     }
 725   }
 726 
 727   static bool should_clean_previous_versions_and_reset();
 728   static bool should_clean_previous_versions() { return _should_clean_previous_versions; }
 729 
 730   // JVMTI: Support for caching a class file before it is modified by an agent that can do retransformation
 731   void set_cached_class_file(JvmtiCachedClassFileData *data) {
 732     _cached_class_file = data;
 733   }
 734   JvmtiCachedClassFileData * get_cached_class_file();
 735   jint get_cached_class_file_len();
 736   unsigned char * get_cached_class_file_bytes();
 737 
 738   // JVMTI: Support for caching of field indices, types, and offsets
 739   void set_jvmti_cached_class_field_map(JvmtiCachedClassFieldMap* descriptor) {
 740     _jvmti_cached_class_field_map = descriptor;
 741   }
 742   JvmtiCachedClassFieldMap* jvmti_cached_class_field_map() const {
 743     return _jvmti_cached_class_field_map;
 744   }
 745 #else // INCLUDE_JVMTI
 746 
 747   static void purge_previous_versions(InstanceKlass* ik) { return; };
 748   static bool should_clean_previous_versions_and_reset() { return false; }
 749 
 750   void set_cached_class_file(JvmtiCachedClassFileData *data) {
 751     assert(data == nullptr, "unexpected call with JVMTI disabled");
 752   }
 753   JvmtiCachedClassFileData * get_cached_class_file() { return (JvmtiCachedClassFileData *)nullptr; }
 754 
 755 #endif // INCLUDE_JVMTI
 756 
 757   bool has_nonstatic_concrete_methods() const { return _misc_flags.has_nonstatic_concrete_methods(); }
 758   void set_has_nonstatic_concrete_methods(bool b) { _misc_flags.set_has_nonstatic_concrete_methods(b); }
 759 
 760   bool declares_nonstatic_concrete_methods() const { return _misc_flags.declares_nonstatic_concrete_methods(); }
 761   void set_declares_nonstatic_concrete_methods(bool b) { _misc_flags.set_declares_nonstatic_concrete_methods(b); }
 762 
 763   bool has_miranda_methods () const     { return _misc_flags.has_miranda_methods(); }
 764   void set_has_miranda_methods()        { _misc_flags.set_has_miranda_methods(true); }
 765   bool has_final_method() const         { return _misc_flags.has_final_method(); }
 766   void set_has_final_method()           { _misc_flags.set_has_final_method(true); }
 767 
 768   // for adding methods, ConstMethod::UNSET_IDNUM means no more ids available
 769   inline u2 next_method_idnum();
 770   void set_initial_method_idnum(u2 value)             { _idnum_allocated_count = value; }
 771 
 772   // generics support
 773   Symbol* generic_signature() const;
 774   u2 generic_signature_index() const;
 775   void set_generic_signature_index(u2 sig_index);
 776 
 777   u2 enclosing_method_data(int offset) const;
 778   u2 enclosing_method_class_index() const {
 779     return enclosing_method_data(enclosing_method_class_index_offset);
 780   }
 781   u2 enclosing_method_method_index() {
 782     return enclosing_method_data(enclosing_method_method_index_offset);
 783   }
 784   void set_enclosing_method_indices(u2 class_index,
 785                                     u2 method_index);
 786 
 787   // jmethodID support
 788   jmethodID get_jmethod_id(const methodHandle& method_h);
 789   void ensure_space_for_methodids(int start_offset = 0);
 790   jmethodID jmethod_id_or_null(Method* method);
 791   void update_methods_jmethod_cache();
 792 
 793   // annotations support
 794   Annotations* annotations() const          { return _annotations; }
 795   void set_annotations(Annotations* anno)   { _annotations = anno; }
 796 
 797   AnnotationArray* class_annotations() const {
 798     return (_annotations != nullptr) ? _annotations->class_annotations() : nullptr;
 799   }
 800   Array<AnnotationArray*>* fields_annotations() const {
 801     return (_annotations != nullptr) ? _annotations->fields_annotations() : nullptr;
 802   }
 803   AnnotationArray* class_type_annotations() const {
 804     return (_annotations != nullptr) ? _annotations->class_type_annotations() : nullptr;
 805   }
 806   Array<AnnotationArray*>* fields_type_annotations() const {
 807     return (_annotations != nullptr) ? _annotations->fields_type_annotations() : nullptr;
 808   }
 809   // allocation
 810   instanceOop allocate_instance(TRAPS);
 811   static instanceOop allocate_instance(oop cls, const char* who, TRAPS);
 812 
 813   // additional member function to return a handle
 814   instanceHandle allocate_instance_handle(TRAPS);
 815 
 816   objArrayOop allocate_objArray(int n, int length, TRAPS);
 817   // Helper function
 818   static instanceOop register_finalizer(instanceOop i, TRAPS);
 819 
 820   // Check whether reflection/jni/jvm code is allowed to instantiate this class;
 821   // if not, throw either an Error or an Exception.
 822   virtual void check_valid_for_instantiation(bool throwError, TRAPS);
 823 
 824   // initialization
 825   void call_class_initializer(TRAPS);
 826   void set_initialization_state_and_notify(ClassState state, TRAPS);
 827 
 828   // OopMapCache support
 829   OopMapCache* oop_map_cache()               { return _oop_map_cache; }
 830   void set_oop_map_cache(OopMapCache *cache) { _oop_map_cache = cache; }
 831   void mask_for(const methodHandle& method, int bci, InterpreterOopMap* entry);
 832 
 833   // JNI identifier support (for static fields - for jni performance)
 834   JNIid* jni_ids()                               { return _jni_ids; }
 835   void set_jni_ids(JNIid* ids)                   { _jni_ids = ids; }
 836   JNIid* jni_id_for(int offset);
 837 
 838  public:
 839   // maintenance of deoptimization dependencies
 840   inline DependencyContext dependencies();
 841   void mark_dependent_nmethods(DeoptimizationScope* deopt_scope, KlassDepChange& changes);
 842   void add_dependent_nmethod(nmethod* nm);
 843   void clean_dependency_context();
 844   // Setup link to hierarchy and deoptimize
 845   void add_to_hierarchy(JavaThread* current);
 846 
 847   // On-stack replacement support
 848   nmethod* osr_nmethods_head() const         { return _osr_nmethods_head; };
 849   void set_osr_nmethods_head(nmethod* h)     { _osr_nmethods_head = h; };
 850   void add_osr_nmethod(nmethod* n);
 851   bool remove_osr_nmethod(nmethod* n);
 852   int mark_osr_nmethods(DeoptimizationScope* deopt_scope, const Method* m);
 853   nmethod* lookup_osr_nmethod(const Method* m, int bci, int level, bool match_level) const;
 854 
 855 #if INCLUDE_JVMTI
 856   // Breakpoint support (see methods on Method* for details)
 857   BreakpointInfo* breakpoints() const       { return _breakpoints; };
 858   void set_breakpoints(BreakpointInfo* bps) { _breakpoints = bps; };
 859 #endif
 860 
 861   // support for stub routines
 862   static ByteSize init_state_offset()  { return byte_offset_of(InstanceKlass, _init_state); }
 863   JFR_ONLY(DEFINE_KLASS_TRACE_ID_OFFSET;)
 864   static ByteSize init_thread_offset() { return byte_offset_of(InstanceKlass, _init_thread); }
 865 
 866   // subclass/subinterface checks
 867   bool implements_interface(Klass* k) const;
 868   bool is_same_or_direct_interface(Klass* k) const;
 869 
 870 #ifdef ASSERT
 871   // check whether this class or one of its superclasses was redefined
 872   bool has_redefined_this_or_super() const;
 873 #endif
 874 
 875   // Access to the implementor of an interface.
 876   InstanceKlass* implementor() const;
 877   void set_implementor(InstanceKlass* ik);
 878   int  nof_implementors() const;
 879   void add_implementor(InstanceKlass* ik);  // ik is a new class that implements this interface
 880   void init_implementor();           // initialize
 881 
 882  private:
 883   // link this class into the implementors list of every interface it implements
 884   void process_interfaces();
 885 
 886  public:
 887   // virtual operations from Klass
 888   GrowableArray<Klass*>* compute_secondary_supers(int num_extra_slots,
 889                                                   Array<InstanceKlass*>* transitive_interfaces);
 890   bool can_be_primary_super_slow() const;
 891   size_t oop_size(oop obj)  const             { return size_helper(); }
 892   // slow because it's a virtual call and used for verifying the layout_helper.
 893   // Using the layout_helper bits, we can call is_instance_klass without a virtual call.
 894   DEBUG_ONLY(bool is_instance_klass_slow() const      { return true; })
 895 
 896   // Iterators
 897   void do_local_static_fields(FieldClosure* cl);
 898   void do_nonstatic_fields(FieldClosure* cl); // including inherited fields
 899   void do_local_static_fields(void f(fieldDescriptor*, Handle, TRAPS), Handle, TRAPS);
 900   void print_nonstatic_fields(FieldClosure* cl); // including inherited and injected fields
 901 
 902   void methods_do(void f(Method* method));
 903 
 904   static InstanceKlass* cast(Klass* k) {
 905     return const_cast<InstanceKlass*>(cast(const_cast<const Klass*>(k)));
 906   }
 907 
 908   static const InstanceKlass* cast(const Klass* k) {
 909     assert(k != nullptr, "k should not be null");
 910     assert(k->is_instance_klass(), "cast to InstanceKlass");
 911     return static_cast<const InstanceKlass*>(k);
 912   }
 913 
 914   virtual InstanceKlass* java_super() const {
 915     return (super() == nullptr) ? nullptr : cast(super());
 916   }
 917 
 918   // Sizing (in words)
 919   static int header_size()            { return sizeof(InstanceKlass)/wordSize; }
 920 
 921   static int size(int vtable_length, int itable_length,
 922                   int nonstatic_oop_map_size,
 923                   bool is_interface) {
 924     return align_metadata_size(header_size() +
 925            vtable_length +
 926            itable_length +
 927            nonstatic_oop_map_size +
 928            (is_interface ? (int)sizeof(Klass*)/wordSize : 0));
 929   }
 930 
 931   int size() const                    { return size(vtable_length(),
 932                                                itable_length(),
 933                                                nonstatic_oop_map_size(),
 934                                                is_interface());
 935   }
 936 
 937 
 938   inline intptr_t* start_of_itable() const;
 939   inline intptr_t* end_of_itable() const;
 940   inline oop static_field_base_raw();
 941 
 942   inline OopMapBlock* start_of_nonstatic_oop_maps() const;
 943   inline Klass** end_of_nonstatic_oop_maps() const;
 944 
 945   inline InstanceKlass* volatile* adr_implementor() const;
 946 
 947   // Use this to return the size of an instance in heap words:
 948   int size_helper() const {
 949     return layout_helper_to_size_helper(layout_helper());
 950   }
 951 
 952   // This bit is initialized in classFileParser.cpp.
 953   // It is false under any of the following conditions:
 954   //  - the class is abstract (including any interface)
 955   //  - the class size is larger than FastAllocateSizeLimit
 956   //  - the class is java/lang/Class, which cannot be allocated directly
 957   bool can_be_fastpath_allocated() const {
 958     return !layout_helper_needs_slow_path(layout_helper());
 959   }
 960 
 961   // Java itable
 962   klassItable itable() const;        // return klassItable wrapper
 963   Method* method_at_itable(InstanceKlass* holder, int index, TRAPS);
 964   Method* method_at_itable_or_null(InstanceKlass* holder, int index, bool& itable_entry_found);
 965   int vtable_index_of_interface_method(Method* method);
 966 
 967 #if INCLUDE_JVMTI
 968   void adjust_default_methods(bool* trace_name_printed);
 969 #endif // INCLUDE_JVMTI
 970 
 971   void clean_weak_instanceklass_links();
 972  private:
 973   void clean_implementors_list();
 974   void clean_method_data();
 975 
 976  public:
 977   // Explicit metaspace deallocation of fields
 978   // For RedefineClasses and class file parsing errors, we need to deallocate
 979   // instanceKlasses and the metadata they point to.
 980   void deallocate_contents(ClassLoaderData* loader_data);
 981   static void deallocate_methods(ClassLoaderData* loader_data,
 982                                  Array<Method*>* methods);
 983   void static deallocate_interfaces(ClassLoaderData* loader_data,
 984                                     const Klass* super_klass,
 985                                     Array<InstanceKlass*>* local_interfaces,
 986                                     Array<InstanceKlass*>* transitive_interfaces);
 987   void static deallocate_record_components(ClassLoaderData* loader_data,
 988                                            Array<RecordComponent*>* record_component);
 989 
 990   virtual bool on_stack() const;
 991 
 992   // callbacks for actions during class unloading
 993   static void unload_class(InstanceKlass* ik);
 994 
 995   virtual void release_C_heap_structures(bool release_sub_metadata = true);
 996 
 997   // Naming
 998   const char* signature_name() const;
 999 
1000   // Oop fields (and metadata) iterators
1001   //
1002   // The InstanceKlass iterators also visits the Object's klass.
1003 
1004   // Forward iteration
1005  public:
1006   // Iterate over all oop fields in the oop maps.
1007   template <typename T, class OopClosureType>
1008   inline void oop_oop_iterate_oop_maps(oop obj, OopClosureType* closure);
1009 
1010   // Iterate over all oop fields and metadata.
1011   template <typename T, class OopClosureType>
1012   inline void oop_oop_iterate(oop obj, OopClosureType* closure);
1013 
1014   // Iterate over all oop fields in one oop map.
1015   template <typename T, class OopClosureType>
1016   inline void oop_oop_iterate_oop_map(OopMapBlock* map, oop obj, OopClosureType* closure);
1017 
1018 
1019   // Reverse iteration
1020   // Iterate over all oop fields and metadata.
1021   template <typename T, class OopClosureType>
1022   inline void oop_oop_iterate_reverse(oop obj, OopClosureType* closure);
1023 
1024  private:
1025   // Iterate over all oop fields in the oop maps.
1026   template <typename T, class OopClosureType>
1027   inline void oop_oop_iterate_oop_maps_reverse(oop obj, OopClosureType* closure);
1028 
1029   // Iterate over all oop fields in one oop map.
1030   template <typename T, class OopClosureType>
1031   inline void oop_oop_iterate_oop_map_reverse(OopMapBlock* map, oop obj, OopClosureType* closure);
1032 
1033 
1034   // Bounded range iteration
1035  public:
1036   // Iterate over all oop fields in the oop maps.
1037   template <typename T, class OopClosureType>
1038   inline void oop_oop_iterate_oop_maps_bounded(oop obj, OopClosureType* closure, MemRegion mr);
1039 
1040   // Iterate over all oop fields and metadata.
1041   template <typename T, class OopClosureType>
1042   inline void oop_oop_iterate_bounded(oop obj, OopClosureType* closure, MemRegion mr);
1043 
1044  private:
1045   // Iterate over all oop fields in one oop map.
1046   template <typename T, class OopClosureType>
1047   inline void oop_oop_iterate_oop_map_bounded(OopMapBlock* map, oop obj, OopClosureType* closure, MemRegion mr);
1048 
1049 
1050  public:
1051   u2 idnum_allocated_count() const      { return _idnum_allocated_count; }
1052 
1053 private:
1054   // initialization state
1055   void set_init_state(ClassState state);
1056   void set_rewritten()                  { _misc_flags.set_rewritten(true); }
1057   void set_init_thread(JavaThread *thread)  {
1058     assert((thread == JavaThread::current() && _init_thread == nullptr) ||
1059            (thread == nullptr && _init_thread == JavaThread::current()), "Only one thread is allowed to own initialization");
1060     Atomic::store(&_init_thread, thread);
1061   }
1062 
1063   inline jmethodID* methods_jmethod_ids_acquire() const;
1064   inline void release_set_methods_jmethod_ids(jmethodID* jmeths);
1065   // This nulls out jmethodIDs for all methods in 'klass'
1066   static void clear_jmethod_ids(InstanceKlass* klass);
1067   jmethodID update_jmethod_id(jmethodID* jmeths, Method* method, int idnum);
1068 
1069 public:
1070   // Lock for (1) initialization; (2) access to the ConstantPool of this class.
1071   // Must be one per class and it has to be a VM internal object so java code
1072   // cannot lock it (like the mirror).
1073   // It has to be an object not a Mutex because it's held through java calls.
1074   oop init_lock() const;
1075 
1076   // Returns the array class for the n'th dimension
1077   virtual ArrayKlass* array_klass(int n, TRAPS);
1078   virtual ArrayKlass* array_klass_or_null(int n);
1079 
1080   // Returns the array class with this class as element type
1081   virtual ArrayKlass* array_klass(TRAPS);
1082   virtual ArrayKlass* array_klass_or_null();
1083 
1084   static void clean_initialization_error_table();
1085 private:
1086   void fence_and_clear_init_lock();
1087 
1088   bool link_class_impl                           (TRAPS);
1089   bool verify_code                               (TRAPS);
1090   void initialize_impl                           (TRAPS);
1091   void initialize_super_interfaces(TRAPS);
1092 
1093   void add_initialization_error(JavaThread* current, Handle exception);
1094   oop get_initialization_error(JavaThread* current);
1095 
1096   // find a local method (returns null if not found)
1097   Method* find_method_impl(const Symbol* name,
1098                            const Symbol* signature,
1099                            OverpassLookupMode overpass_mode,
1100                            StaticLookupMode static_mode,
1101                            PrivateLookupMode private_mode) const;
1102 
1103   static Method* find_method_impl(const Array<Method*>* methods,
1104                                   const Symbol* name,
1105                                   const Symbol* signature,
1106                                   OverpassLookupMode overpass_mode,
1107                                   StaticLookupMode static_mode,
1108                                   PrivateLookupMode private_mode);
1109 
1110 #if INCLUDE_JVMTI
1111   // RedefineClasses support
1112   void link_previous_versions(InstanceKlass* pv) { _previous_versions = pv; }
1113   void mark_newly_obsolete_methods(Array<Method*>* old_methods, int emcp_method_count);
1114 #endif
1115   // log class name to classlist
1116   void log_to_classlist() const;
1117 public:
1118 
1119 #if INCLUDE_CDS
1120   // CDS support - remove and restore oops from metadata. Oops are not shared.
1121   virtual void remove_unshareable_info();
1122   void remove_unshareable_flags();
1123   virtual void remove_java_mirror();
1124   void restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, PackageEntry* pkg_entry, TRAPS);
1125   void init_shared_package_entry();
1126   bool can_be_verified_at_dumptime() const;
1127   void compute_has_loops_flag_for_methods();
1128 #endif
1129 
1130   bool     has_init_deps_processed() const { return _misc_flags.has_init_deps_processed(); }
1131   void set_has_init_deps_processed() {
1132     assert(is_initialized(), "");
1133     assert(!has_init_deps_processed(), "already set"); // one-off action
1134     _misc_flags.set_has_init_deps_processed(true);
1135   }
1136 
1137   u2 compute_modifier_flags() const;
1138 
1139 public:
1140   // JVMTI support
1141   jint jvmti_class_status() const;
1142 
1143   virtual void metaspace_pointers_do(MetaspaceClosure* iter);
1144 
1145  public:
1146   // Printing
1147   void print_on(outputStream* st) const;
1148   void print_value_on(outputStream* st) const;
1149 
1150   void oop_print_value_on(oop obj, outputStream* st);
1151 
1152   void oop_print_on      (oop obj, outputStream* st);
1153 
1154 #ifndef PRODUCT
1155   void print_dependent_nmethods(bool verbose = false);
1156   bool is_dependent_nmethod(nmethod* nm);
1157   bool verify_itable_index(int index);
1158 #endif
1159 
1160   const char* internal_name() const;
1161 
1162   // Verification
1163   void verify_on(outputStream* st);
1164 
1165   void oop_verify_on(oop obj, outputStream* st);
1166 
1167   // Logging
1168   void print_class_load_logging(ClassLoaderData* loader_data,
1169                                 const ModuleEntry* module_entry,
1170                                 const ClassFileStream* cfs) const;
1171  private:
1172   void print_class_load_cause_logging() const;
1173   void print_class_load_helper(ClassLoaderData* loader_data,
1174                                const ModuleEntry* module_entry,
1175                                const ClassFileStream* cfs) const;
1176 };
1177 
1178 // for adding methods
1179 // UNSET_IDNUM return means no more ids available
1180 inline u2 InstanceKlass::next_method_idnum() {
1181   if (_idnum_allocated_count == ConstMethod::MAX_IDNUM) {
1182     return ConstMethod::UNSET_IDNUM; // no more ids available
1183   } else {
1184     return _idnum_allocated_count++;
1185   }
1186 }
1187 
1188 class PrintClassClosure : public KlassClosure {
1189 private:
1190   outputStream* _st;
1191   bool _verbose;
1192 public:
1193   PrintClassClosure(outputStream* st, bool verbose);
1194 
1195   void do_klass(Klass* k);
1196 };
1197 
1198 /* JNIid class for jfieldIDs only */
1199 class JNIid: public CHeapObj<mtClass> {
1200   friend class VMStructs;
1201  private:
1202   Klass*             _holder;
1203   JNIid*             _next;
1204   int                _offset;
1205 #ifdef ASSERT
1206   bool               _is_static_field_id;
1207 #endif
1208 
1209  public:
1210   // Accessors
1211   Klass* holder() const           { return _holder; }
1212   int offset() const              { return _offset; }
1213   JNIid* next()                   { return _next; }
1214   // Constructor
1215   JNIid(Klass* holder, int offset, JNIid* next);
1216   // Identifier lookup
1217   JNIid* find(int offset);
1218 
1219   bool find_local_field(fieldDescriptor* fd) {
1220     return InstanceKlass::cast(holder())->find_local_field_from_offset(offset(), true, fd);
1221   }
1222 
1223   static void deallocate(JNIid* id);
1224   // Debugging
1225 #ifdef ASSERT
1226   bool is_static_field_id() const { return _is_static_field_id; }
1227   void set_is_static_field_id()   { _is_static_field_id = true; }
1228 #endif
1229   void verify(Klass* holder);
1230 };
1231 
1232 // An iterator that's used to access the inner classes indices in the
1233 // InstanceKlass::_inner_classes array.
1234 class InnerClassesIterator : public StackObj {
1235  private:
1236   Array<jushort>* _inner_classes;
1237   int _length;
1238   int _idx;
1239  public:
1240 
1241   InnerClassesIterator(const InstanceKlass* k) {
1242     _inner_classes = k->inner_classes();
1243     if (k->inner_classes() != nullptr) {
1244       _length = _inner_classes->length();
1245       // The inner class array's length should be the multiple of
1246       // inner_class_next_offset if it only contains the InnerClasses
1247       // attribute data, or it should be
1248       // n*inner_class_next_offset+enclosing_method_attribute_size
1249       // if it also contains the EnclosingMethod data.
1250       assert((_length % InstanceKlass::inner_class_next_offset == 0 ||
1251               _length % InstanceKlass::inner_class_next_offset == InstanceKlass::enclosing_method_attribute_size),
1252              "just checking");
1253       // Remove the enclosing_method portion if exists.
1254       if (_length % InstanceKlass::inner_class_next_offset == InstanceKlass::enclosing_method_attribute_size) {
1255         _length -= InstanceKlass::enclosing_method_attribute_size;
1256       }
1257     } else {
1258       _length = 0;
1259     }
1260     _idx = 0;
1261   }
1262 
1263   int length() const {
1264     return _length;
1265   }
1266 
1267   void next() {
1268     _idx += InstanceKlass::inner_class_next_offset;
1269   }
1270 
1271   bool done() const {
1272     return (_idx >= _length);
1273   }
1274 
1275   u2 inner_class_info_index() const {
1276     return _inner_classes->at(
1277                _idx + InstanceKlass::inner_class_inner_class_info_offset);
1278   }
1279 
1280   void set_inner_class_info_index(u2 index) {
1281     _inner_classes->at_put(
1282                _idx + InstanceKlass::inner_class_inner_class_info_offset, index);
1283   }
1284 
1285   u2 outer_class_info_index() const {
1286     return _inner_classes->at(
1287                _idx + InstanceKlass::inner_class_outer_class_info_offset);
1288   }
1289 
1290   void set_outer_class_info_index(u2 index) {
1291     _inner_classes->at_put(
1292                _idx + InstanceKlass::inner_class_outer_class_info_offset, index);
1293   }
1294 
1295   u2 inner_name_index() const {
1296     return _inner_classes->at(
1297                _idx + InstanceKlass::inner_class_inner_name_offset);
1298   }
1299 
1300   void set_inner_name_index(u2 index) {
1301     _inner_classes->at_put(
1302                _idx + InstanceKlass::inner_class_inner_name_offset, index);
1303   }
1304 
1305   u2 inner_access_flags() const {
1306     return _inner_classes->at(
1307                _idx + InstanceKlass::inner_class_access_flags_offset);
1308   }
1309 };
1310 
1311 // Iterator over class hierarchy under a particular class. Implements depth-first pre-order traversal.
1312 // Usage:
1313 //  for (ClassHierarchyIterator iter(root_klass); !iter.done(); iter.next()) {
1314 //    Klass* k = iter.klass();
1315 //    ...
1316 //  }
1317 class ClassHierarchyIterator : public StackObj {
1318  private:
1319   InstanceKlass* _root;
1320   Klass*         _current;
1321   bool           _visit_subclasses;
1322 
1323  public:
1324   ClassHierarchyIterator(InstanceKlass* root) : _root(root), _current(root), _visit_subclasses(true) {
1325     assert(_root == _current, "required"); // initial state
1326   }
1327 
1328   bool done() {
1329     return (_current == nullptr);
1330   }
1331 
1332   // Make a step iterating over the class hierarchy under the root class.
1333   // Skips subclasses if requested.
1334   void next();
1335 
1336   Klass* klass() {
1337     assert(!done(), "sanity");
1338     return _current;
1339   }
1340 
1341   // Skip subclasses of the current class.
1342   void skip_subclasses() {
1343     _visit_subclasses = false;
1344   }
1345 };
1346 
1347 #endif // SHARE_OOPS_INSTANCEKLASS_HPP