1 /*
   2  * Copyright (c) 1997, 2026, 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 "code/vmreg.hpp"
  29 #include "memory/allocation.hpp"
  30 #include "memory/referenceType.hpp"
  31 #include "oops/annotations.hpp"
  32 #include "oops/arrayKlass.hpp"
  33 #include "oops/constMethod.hpp"
  34 #include "oops/fieldInfo.hpp"
  35 #include "oops/instanceKlassFlags.hpp"
  36 #include "oops/instanceOop.hpp"
  37 #include "oops/refArrayKlass.hpp"
  38 #include "runtime/handles.hpp"
  39 #include "runtime/javaThread.hpp"
  40 #include "utilities/accessFlags.hpp"
  41 #include "utilities/align.hpp"
  42 #include "utilities/growableArray.hpp"
  43 #include "utilities/macros.hpp"
  44 #if INCLUDE_JFR
  45 #include "jfr/support/jfrKlassExtension.hpp"
  46 #endif
  47 
  48 class ConstantPool;
  49 class DeoptimizationScope;
  50 class klassItable;
  51 class RecordComponent;
  52 
  53 // An InstanceKlass is the VM level representation of a Java class.
  54 // It contains all information needed for at class at execution runtime.
  55 
  56 //  InstanceKlass embedded field layout (after declared fields):
  57 //    [EMBEDDED Java vtable             ] size in words = vtable_len
  58 //    [EMBEDDED nonstatic oop-map blocks] size in words = nonstatic_oop_map_size
  59 //      The embedded nonstatic oop-map blocks are short pairs (offset, length)
  60 //      indicating where oops are located in instances of this klass.
  61 //    [EMBEDDED implementor of the interface] only exist for interface
  62 //    [EMBEDDED InlineKlass::Members] only if is an InlineKlass instance
  63 
  64 
  65 // forward declaration for class -- see below for definition
  66 #if INCLUDE_JVMTI
  67 class BreakpointInfo;
  68 #endif
  69 class ClassFileParser;
  70 class ClassFileStream;
  71 class KlassDepChange;
  72 class DependencyContext;
  73 class fieldDescriptor;
  74 class JNIid;
  75 class JvmtiCachedClassFieldMap;
  76 class nmethodBucket;
  77 class OopMapCache;
  78 class BufferedInlineTypeBlob;
  79 class InterpreterOopMap;
  80 class PackageEntry;
  81 class ModuleEntry;
  82 
  83 // This is used in iterators below.
  84 class FieldClosure: public StackObj {
  85 public:
  86   virtual void do_field(fieldDescriptor* fd) = 0;
  87 };
  88 
  89 // Print fields.
  90 // If "obj" argument to constructor is null, prints fields as if they are static fields,
  91 // otherwise prints non-static fields. It is possible to print non-static fields the same
  92 // way as static fields when no oops are available, such as when debug printing classes.
  93 class FieldPrinter: public FieldClosure {
  94    oop _obj;
  95    outputStream* _st;
  96    int _indent;
  97    int _base_offset;
  98  public:
  99    FieldPrinter(outputStream* st, oop obj = nullptr, int indent = 0, int base_offset = 0) :
 100                  _obj(obj), _st(st), _indent(indent), _base_offset(base_offset) {}
 101    void do_field(fieldDescriptor* fd);
 102 };
 103 
 104 // Describes where oops are located in instances of this klass.
 105 class OopMapBlock {
 106  public:
 107   // Byte offset of the first oop mapped by this block.
 108   int offset() const          { return _offset; }
 109   void set_offset(int offset) { _offset = offset; }
 110 
 111   // Number of oops in this block.
 112   uint count() const         { return _count; }
 113   void set_count(uint count) { _count = count; }
 114 
 115   void increment_count(int diff) { _count += diff; }
 116 
 117   int offset_span() const { return _count * heapOopSize; }
 118 
 119   int end_offset() const {
 120     return offset() + offset_span();
 121   }
 122 
 123   bool is_contiguous(int another_offset) const {
 124     return another_offset == end_offset();
 125   }
 126 
 127   // sizeof(OopMapBlock) in words.
 128   static int size_in_words() {
 129     return align_up((int)sizeof(OopMapBlock), wordSize) >>
 130       LogBytesPerWord;
 131   }
 132 
 133   static int compare_offset(const OopMapBlock* a, const OopMapBlock* b) {
 134     return a->offset() - b->offset();
 135   }
 136 
 137  private:
 138   int  _offset;
 139   uint _count;
 140 };
 141 
 142 struct JvmtiCachedClassFileData;
 143 
 144 class InlineLayoutInfo : public MetaspaceObj {
 145   InlineKlass* _klass;
 146   LayoutKind _kind;
 147   int _null_marker_offset; // null marker offset for this field, relative to the beginning of the current container
 148 
 149  public:
 150   InlineLayoutInfo(): _klass(nullptr), _kind(LayoutKind::UNKNOWN), _null_marker_offset(-1)  {}
 151 
 152   InlineKlass* klass() const { return _klass; }
 153   void set_klass(InlineKlass* k) { _klass = k; }
 154 
 155   LayoutKind kind() const {
 156     assert(_kind != LayoutKind::UNKNOWN, "Not set");
 157     return _kind;
 158   }
 159   void set_kind(LayoutKind lk) { _kind = lk; }
 160 
 161   int null_marker_offset() const {
 162     assert(_null_marker_offset != -1, "Not set");
 163     return _null_marker_offset;
 164   }
 165   void set_null_marker_offset(int o) { _null_marker_offset = o; }
 166 
 167   void metaspace_pointers_do(MetaspaceClosure* it);
 168   MetaspaceObj::Type type() const { return InlineLayoutInfoType; }
 169 
 170   static ByteSize klass_offset() { return byte_offset_of(InlineLayoutInfo, _klass); }
 171   static ByteSize null_marker_offset_offset() { return byte_offset_of(InlineLayoutInfo, _null_marker_offset); }
 172 
 173   // Print
 174   void print() const;
 175   void print_on(outputStream* st) const;
 176 };
 177 
 178 class InstanceKlass: public Klass {
 179   friend class VMStructs;
 180   friend class JVMCIVMStructs;
 181   friend class ClassFileParser;
 182   friend class CompileReplay;
 183   friend class TemplateTable;
 184 
 185  public:
 186   static const KlassKind Kind = InstanceKlassKind;
 187 
 188  protected:
 189   InstanceKlass(const ClassFileParser& parser, KlassKind kind = Kind, markWord prototype = markWord::prototype(), ReferenceType reference_type = REF_NONE);
 190 
 191  public:
 192   InstanceKlass();
 193 
 194   // See "The Java Virtual Machine Specification" section 2.16.2-5 for a detailed description
 195   // of the class loading & initialization procedure, and the use of the states.
 196   enum ClassState : u1 {
 197     allocated,                          // allocated (but not yet linked)
 198     loaded,                             // loaded and inserted in class hierarchy (but not linked yet)
 199     linked,                             // successfully linked/verified (but not initialized yet)
 200     being_initialized,                  // currently running class initializer
 201     fully_initialized,                  // initialized (successful final state)
 202     initialization_error                // error happened during initialization
 203   };
 204 
 205  private:
 206   static InstanceKlass* allocate_instance_klass(const ClassFileParser& parser, TRAPS);
 207 
 208  protected:
 209   // If you add a new field that points to any metaspace object, you
 210   // must add this field to InstanceKlass::metaspace_pointers_do().
 211 
 212   // Annotations for this class
 213   Annotations*    _annotations;
 214   // Package this class is defined in
 215   PackageEntry*   _package_entry;
 216   // Array classes holding elements of this class.
 217   ObjArrayKlass* volatile _array_klasses;
 218   // Constant pool for this class.
 219   ConstantPool* _constants;
 220   // The InnerClasses attribute and EnclosingMethod attribute. The
 221   // _inner_classes is an array of shorts. If the class has InnerClasses
 222   // attribute, then the _inner_classes array begins with 4-tuples of shorts
 223   // [inner_class_info_index, outer_class_info_index,
 224   // inner_name_index, inner_class_access_flags] for the InnerClasses
 225   // attribute. If the EnclosingMethod attribute exists, it occupies the
 226   // last two shorts [class_index, method_index] of the array. If only
 227   // the InnerClasses attribute exists, the _inner_classes array length is
 228   // number_of_inner_classes * 4. If the class has both InnerClasses
 229   // and EnclosingMethod attributes the _inner_classes array length is
 230   // number_of_inner_classes * 4 + enclosing_method_attribute_size.
 231   Array<jushort>* _inner_classes;
 232 
 233   // The NestMembers attribute. An array of shorts, where each is a
 234   // class info index for the class that is a nest member. This data
 235   // has not been validated.
 236   Array<jushort>* _nest_members;
 237 
 238   // Resolved nest-host klass: either true nest-host or self if we are not
 239   // nested, or an error occurred resolving or validating the nominated
 240   // nest-host. Can also be set directly by JDK API's that establish nest
 241   // relationships.
 242   // By always being set it makes nest-member access checks simpler.
 243   InstanceKlass* _nest_host;
 244 
 245   // The PermittedSubclasses attribute. An array of shorts, where each is a
 246   // class info index for the class that is a permitted subclass.
 247   Array<jushort>* _permitted_subclasses;
 248 
 249   // The contents of the Record attribute.
 250   Array<RecordComponent*>* _record_components;
 251 
 252   // the source debug extension for this klass, null if not specified.
 253   // Specified as UTF-8 string without terminating zero byte in the classfile,
 254   // it is stored in the instanceklass as a null-terminated UTF-8 string
 255   const char*     _source_debug_extension;
 256 
 257   // Number of heapOopSize words used by non-static fields in this klass
 258   // (including inherited fields but after header_size()).
 259   int             _nonstatic_field_size;
 260   int             _static_field_size;       // number words used by static fields (oop and non-oop) in this klass
 261   int             _nonstatic_oop_map_size;  // size in words of nonstatic oop map blocks
 262   int             _itable_len;              // length of Java itable (in words)
 263 
 264   // The NestHost attribute. The class info index for the class
 265   // that is the nest-host of this class. This data has not been validated.
 266   u2              _nest_host_index;
 267   u2              _this_class_index;        // constant pool entry
 268   u2              _static_oop_field_count;  // number of static oop fields in this klass
 269 
 270   volatile u2     _idnum_allocated_count;   // JNI/JVMTI: increments with the addition of methods, old ids don't change
 271 
 272   // Class states are defined as ClassState (see above).
 273   // Place the _init_state here to utilize the unused 2-byte after
 274   // _idnum_allocated_count.
 275   volatile ClassState _init_state;          // state of class
 276 
 277   u1              _reference_type;          // reference type
 278   int             _acmp_maps_offset;        // offset to injected static field storing .acmp_maps for values classes
 279                                             // unfortunately, abstract values need one too so it cannot be stored in
 280                                             // the InlineKlass::Members that only exist for InlineKlass.
 281 
 282   AccessFlags        _access_flags;    // Access flags. The class/interface distinction is stored here.
 283 
 284   // State is set either at parse time or while executing, atomically to not disturb other state
 285   InstanceKlassFlags _misc_flags;
 286 
 287   JavaThread* volatile _init_thread;        // Pointer to current thread doing initialization (to handle recursive initialization)
 288 
 289   OopMapCache*    volatile _oop_map_cache;   // OopMapCache for all methods in the klass (allocated lazily)
 290   JNIid*          _jni_ids;                  // First JNI identifier for static fields in this class
 291   jmethodID* volatile _methods_jmethod_ids;  // jmethodIDs corresponding to method_idnum, or null if none
 292   nmethodBucket*  volatile _dep_context;     // packed DependencyContext structure
 293   uint64_t        volatile _dep_context_last_cleaned;
 294   nmethod*        _osr_nmethods_head;    // Head of list of on-stack replacement nmethods for this class
 295 #if INCLUDE_JVMTI
 296   BreakpointInfo* _breakpoints;          // bpt lists, managed by Method*
 297   // Linked instanceKlasses of previous versions
 298   InstanceKlass* _previous_versions;
 299   // JVMTI fields can be moved to their own structure - see 6315920
 300   // JVMTI: cached class file, before retransformable agent modified it in CFLH
 301   JvmtiCachedClassFileData* _cached_class_file;
 302 #endif
 303 
 304 #if INCLUDE_JVMTI
 305   JvmtiCachedClassFieldMap* _jvmti_cached_class_field_map;  // JVMTI: used during heap iteration
 306 #endif
 307 
 308   NOT_PRODUCT(int _verify_count;)  // to avoid redundant verifies
 309   NOT_PRODUCT(volatile int _shared_class_load_count;) // ensure a shared class is loaded only once
 310 
 311   // Method array.
 312   Array<Method*>* _methods;
 313   // Default Method Array, concrete methods inherited from interfaces
 314   Array<Method*>* _default_methods;
 315   // Interfaces (InstanceKlass*s) this class declares locally to implement.
 316   Array<InstanceKlass*>* _local_interfaces;
 317   // Interfaces (InstanceKlass*s) this class implements transitively.
 318   Array<InstanceKlass*>* _transitive_interfaces;
 319   // Int array containing the original order of method in the class file (for JVMTI).
 320   Array<int>*     _method_ordering;
 321   // Int array containing the vtable_indices for default_methods
 322   // offset matches _default_methods offset
 323   Array<int>*     _default_vtable_indices;
 324 
 325   // Fields information is stored in an UNSIGNED5 encoded stream (see fieldInfo.hpp)
 326   Array<u1>*          _fieldinfo_stream;
 327   Array<u1>*          _fieldinfo_search_table;
 328   Array<FieldStatus>* _fields_status;
 329 
 330   Array<InlineLayoutInfo>* _inline_layout_info_array;
 331   Array<u2>* _loadable_descriptors;
 332   Array<int>* _acmp_maps_array; // Metadata copy of the acmp_maps oop used in value classes.
 333                                 // When loading an inline klass from the CDS/AOT archive
 334                                 // this copy can be used to regenerate the ".acmp_maps" oop
 335                                 // if it is not stored in the archive.
 336 
 337   // Located here because sub-klasses can't have their own C++ fields
 338   address _adr_inline_klass_members;
 339 
 340   // embedded Java vtable follows here
 341   // embedded Java itables follows here
 342   // embedded static fields follows here
 343   // embedded nonstatic oop-map blocks follows here
 344   // embedded implementor of this interface follows here
 345   //   The embedded implementor only exists if the current klass is an
 346   //   interface. The possible values of the implementor fall into following
 347   //   three cases:
 348   //     null: no implementor.
 349   //     A Klass* that's not itself: one implementor.
 350   //     Itself: more than one implementors.
 351   //
 352 
 353   friend class SystemDictionary;
 354 
 355   static bool _disable_method_binary_search;
 356 
 357   // Controls finalizer registration
 358   static bool _finalization_enabled;
 359 
 360  public:
 361 
 362   // Queries finalization state
 363   static bool is_finalization_enabled() { return _finalization_enabled; }
 364 
 365   // Sets finalization state
 366   static void set_finalization_enabled(bool val) { _finalization_enabled = val; }
 367 
 368   // Access flags
 369   AccessFlags access_flags() const         { return _access_flags;  }
 370   void set_access_flags(AccessFlags flags) { _access_flags = flags; }
 371 
 372   bool is_public() const                { return _access_flags.is_public(); }
 373   bool is_final() const                 { return _access_flags.is_final(); }
 374   bool is_interface() const override    { return _access_flags.is_interface(); }
 375   bool is_abstract() const override     { return _access_flags.is_abstract(); }
 376   bool is_synthetic() const             { return _access_flags.is_synthetic(); }
 377   void set_is_synthetic()               { _access_flags.set_is_synthetic(); }
 378   bool is_identity_class() const override { return _access_flags.is_identity_class(); }
 379 
 380   static ByteSize access_flags_offset() { return byte_offset_of(InstanceKlass, _access_flags); }
 381 
 382   void set_is_cloneable();
 383 
 384   // Quick checks for the loader that defined this class (without switching on this->class_loader())
 385   bool defined_by_boot_loader() const      { return _misc_flags.defined_by_boot_loader(); }
 386   bool defined_by_platform_loader() const  { return _misc_flags.defined_by_platform_loader(); }
 387   bool defined_by_app_loader() const       { return _misc_flags.defined_by_app_loader(); }
 388   bool defined_by_other_loaders() const    { return _misc_flags.defined_by_other_loaders(); }
 389   void set_class_loader_type()             { _misc_flags.set_class_loader_type(_class_loader_data); }
 390 
 391   bool shared_loading_failed() const { return _misc_flags.shared_loading_failed(); }
 392 
 393   void set_shared_loading_failed() { _misc_flags.set_shared_loading_failed(true); }
 394 
 395   bool has_nonstatic_fields() const        { return _misc_flags.has_nonstatic_fields(); }
 396   void set_has_nonstatic_fields(bool b)    { _misc_flags.set_has_nonstatic_fields(b); }
 397 
 398   bool has_localvariable_table() const     { return _misc_flags.has_localvariable_table(); }
 399   void set_has_localvariable_table(bool b) { _misc_flags.set_has_localvariable_table(b); }
 400 
 401   bool has_inlined_fields() const { return _misc_flags.has_inlined_fields(); }
 402   void set_has_inlined_fields()   { _misc_flags.set_has_inlined_fields(true); }
 403 
 404   bool is_naturally_atomic(bool null_free) const;
 405   void set_is_naturally_atomic()    { _misc_flags.set_is_naturally_atomic(true); }
 406 
 407   // Query if this class has atomicity requirements (default is yes)
 408   // This bit can occur anywhere, but is only significant
 409   // for inline classes *and* their super types.
 410   // It inherits from supers.
 411   // Its value depends on the ForceNonTearable VM option, the LooselyConsistentValue annotation
 412   // and the presence of flat fields with atomicity requirements
 413   bool must_be_atomic() const { return _misc_flags.must_be_atomic(); }
 414   void set_must_be_atomic()   { _misc_flags.set_must_be_atomic(true); }
 415 
 416   // field sizes
 417   int nonstatic_field_size() const         { return _nonstatic_field_size; }
 418   void set_nonstatic_field_size(int size)  { _nonstatic_field_size = size; }
 419 
 420   int static_field_size() const            { return _static_field_size; }
 421   void set_static_field_size(int size)     { _static_field_size = size; }
 422 
 423   int static_oop_field_count() const       { return (int)_static_oop_field_count; }
 424   void set_static_oop_field_count(u2 size) { _static_oop_field_count = size; }
 425 
 426   bool trust_final_fields()                { return _misc_flags.trust_final_fields(); }
 427   void set_trust_final_fields(bool value)  { _misc_flags.set_trust_final_fields(value); }
 428 
 429   // Java itable
 430   int  itable_length() const               { return _itable_len; }
 431   void set_itable_length(int len)          { _itable_len = len; }
 432 
 433   // array klasses
 434   ObjArrayKlass* array_klasses() const     { return _array_klasses; }
 435   inline ObjArrayKlass* array_klasses_acquire() const; // load with acquire semantics
 436   inline void release_set_array_klasses(ObjArrayKlass* k); // store with release semantics
 437   void set_array_klasses(ObjArrayKlass* k) { _array_klasses = k; }
 438 
 439   // methods
 440   Array<Method*>* methods() const          { return _methods; }
 441   void set_methods(Array<Method*>* a)      { _methods = a; }
 442   Method* method_with_idnum(int idnum) const;
 443   Method* method_with_orig_idnum(int idnum) const;
 444   Method* method_with_orig_idnum(int idnum, int version) const;
 445 
 446   // method ordering
 447   Array<int>* method_ordering() const     { return _method_ordering; }
 448   void set_method_ordering(Array<int>* m) { _method_ordering = m; }
 449   void copy_method_ordering(const intArray* m, TRAPS);
 450 
 451   // default_methods
 452   Array<Method*>* default_methods() const  { return _default_methods; }
 453   void set_default_methods(Array<Method*>* a) { _default_methods = a; }
 454 
 455   // default method vtable_indices
 456   Array<int>* default_vtable_indices() const { return _default_vtable_indices; }
 457   void set_default_vtable_indices(Array<int>* v) { _default_vtable_indices = v; }
 458   Array<int>* create_new_default_vtable_indices(int len, TRAPS);
 459 
 460   // interfaces
 461   Array<InstanceKlass*>* local_interfaces() const          { return _local_interfaces; }
 462   void set_local_interfaces(Array<InstanceKlass*>* a)      {
 463     guarantee(_local_interfaces == nullptr || a == nullptr, "Just checking");
 464     _local_interfaces = a; }
 465 
 466   Array<InstanceKlass*>* transitive_interfaces() const     { return _transitive_interfaces; }
 467   void set_transitive_interfaces(Array<InstanceKlass*>* a) {
 468     guarantee(_transitive_interfaces == nullptr || a == nullptr, "Just checking");
 469     _transitive_interfaces = a;
 470   }
 471 
 472  private:
 473   friend class fieldDescriptor;
 474   FieldInfo field(int index) const;
 475 
 476  public:
 477   int     field_offset      (int index) const { return field(index).offset(); }
 478   int     field_access_flags(int index) const { return field(index).access_flags().as_field_flags(); }
 479   FieldInfo::FieldFlags field_flags(int index) const { return field(index).field_flags(); }
 480   FieldStatus field_status(int index)   const { return fields_status()->at(index); }
 481   inline Symbol* field_name        (int index) const;
 482   inline Symbol* field_signature   (int index) const;
 483   bool field_is_flat(int index) const { return field_flags(index).is_flat(); }
 484   bool field_has_null_marker(int index) const { return field_flags(index).has_null_marker(); }
 485   bool field_is_null_free_inline_type(int index) const;
 486   bool is_class_in_loadable_descriptors_attribute(Symbol* name) const;
 487 
 488   int field_null_marker_offset(int index) const { return inline_layout_info(index).null_marker_offset(); }
 489 
 490   // Number of Java declared fields
 491   int java_fields_count() const;
 492   int total_fields_count() const;
 493 
 494   Array<u1>* fieldinfo_stream() const { return _fieldinfo_stream; }
 495   void set_fieldinfo_stream(Array<u1>* fis) { _fieldinfo_stream = fis; }
 496 
 497   Array<u1>* fieldinfo_search_table() const { return _fieldinfo_search_table; }
 498   void set_fieldinfo_search_table(Array<u1>* table) { _fieldinfo_search_table = table; }
 499 
 500   Array<FieldStatus>* fields_status() const {return _fields_status; }
 501   void set_fields_status(Array<FieldStatus>* array) { _fields_status = array; }
 502 
 503   Array<u2>* loadable_descriptors() const { return _loadable_descriptors; }
 504   void set_loadable_descriptors(Array<u2>* c) { _loadable_descriptors = c; }
 505 
 506   Array<int>* acmp_maps_array() const { return _acmp_maps_array; }
 507   void set_acmp_maps_array(Array<int>* array) { _acmp_maps_array = array; }
 508 
 509   // inner classes
 510   Array<u2>* inner_classes() const       { return _inner_classes; }
 511   void set_inner_classes(Array<u2>* f)   { _inner_classes = f; }
 512 
 513   // nest members
 514   Array<u2>* nest_members() const     { return _nest_members; }
 515   void set_nest_members(Array<u2>* m) { _nest_members = m; }
 516 
 517   // nest-host index
 518   jushort nest_host_index() const { return _nest_host_index; }
 519   void set_nest_host_index(u2 i)  { _nest_host_index = i; }
 520   // dynamic nest member support
 521   void set_nest_host(InstanceKlass* host);
 522 
 523   // record components
 524   Array<RecordComponent*>* record_components() const { return _record_components; }
 525   void set_record_components(Array<RecordComponent*>* record_components) {
 526     _record_components = record_components;
 527   }
 528   bool is_record() const;
 529 
 530   // test for enum class (or possibly an anonymous subclass within a sealed enum)
 531   bool is_enum_subclass() const;
 532 
 533   // permitted subclasses
 534   Array<u2>* permitted_subclasses() const     { return _permitted_subclasses; }
 535   void set_permitted_subclasses(Array<u2>* s) { _permitted_subclasses = s; }
 536 
 537 private:
 538   // Called to verify that k is a member of this nest - does not look at k's nest-host,
 539   // nor does it resolve any CP entries or load any classes.
 540   bool has_nest_member(JavaThread* current, InstanceKlass* k) const;
 541 
 542 public:
 543   // Call this only if you know that the nest host has been initialized.
 544   InstanceKlass* nest_host_not_null() {
 545     assert(_nest_host != nullptr, "must be");
 546     return _nest_host;
 547   }
 548   InstanceKlass* nest_host_or_null() {
 549     return _nest_host;
 550   }
 551   // Used to construct informative IllegalAccessError messages at a higher level,
 552   // if there was an issue resolving or validating the nest host.
 553   // Returns null if there was no error.
 554   const char* nest_host_error();
 555   // Returns nest-host class, resolving and validating it if needed.
 556   // Returns null if resolution is not possible from the calling context.
 557   InstanceKlass* nest_host(TRAPS);
 558   // Check if this klass is a nestmate of k - resolves this nest-host and k's
 559   bool has_nestmate_access_to(InstanceKlass* k, TRAPS);
 560 
 561   // Called to verify that k is a permitted subclass of this class.
 562   // The incoming stringStream is used for logging, and for the caller to create
 563   // a detailed exception message on failure.
 564   bool has_as_permitted_subclass(const InstanceKlass* k, stringStream& ss) const;
 565 
 566   enum InnerClassAttributeOffset {
 567     // From http://mirror.eng/products/jdk/1.1/docs/guide/innerclasses/spec/innerclasses.doc10.html#18814
 568     inner_class_inner_class_info_offset = 0,
 569     inner_class_outer_class_info_offset = 1,
 570     inner_class_inner_name_offset = 2,
 571     inner_class_access_flags_offset = 3,
 572     inner_class_next_offset = 4
 573   };
 574 
 575   enum EnclosingMethodAttributeOffset {
 576     enclosing_method_class_index_offset = 0,
 577     enclosing_method_method_index_offset = 1,
 578     enclosing_method_attribute_size = 2
 579   };
 580 
 581   // package
 582   PackageEntry* package() const override { return _package_entry; }
 583   ModuleEntry* module() const override;
 584   bool in_javabase_module() const;
 585   bool in_unnamed_package() const   { return (_package_entry == nullptr); }
 586   void set_package(ClassLoaderData* loader_data, PackageEntry* pkg_entry, TRAPS);
 587   // If the package for the InstanceKlass is in the boot loader's package entry
 588   // table then sets the classpath_index field so that
 589   // get_system_package() will know to return a non-null value for the
 590   // package's location.  And, so that the package will be added to the list of
 591   // packages returned by get_system_packages().
 592   // For packages whose classes are loaded from the boot loader class path, the
 593   // classpath_index indicates which entry on the boot loader class path.
 594   void set_classpath_index(s2 path_index);
 595   bool is_same_class_package(const Klass* class2) const;
 596   bool is_same_class_package(oop other_class_loader, const Symbol* other_class_name) const;
 597 
 598   // find an enclosing class
 599   InstanceKlass* compute_enclosing_class(bool* inner_is_member, TRAPS) const;
 600 
 601   // Find InnerClasses attribute and return outer_class_info_index & inner_name_index.
 602   bool find_inner_classes_attr(int* ooff, int* noff, TRAPS) const;
 603 
 604   // Check if this klass can be null-free
 605   static void check_can_be_annotated_with_NullRestricted(InstanceKlass* type, Symbol* container_klass_name, TRAPS);
 606 
 607  private:
 608   // Check prohibited package ("java/" only loadable by boot or platform loaders)
 609   static void check_prohibited_package(Symbol* class_name,
 610                                        ClassLoaderData* loader_data,
 611                                        TRAPS);
 612 
 613   JavaThread* init_thread()  { return AtomicAccess::load(&_init_thread); }
 614   const char* init_thread_name() {
 615     return init_thread()->name_raw();
 616   }
 617 
 618  public:
 619   // initialization state
 620   bool is_loaded() const                   { return init_state() >= loaded; }
 621   bool is_linked() const                   { return init_state() >= linked; }
 622   bool is_initialized() const              { return init_state() == fully_initialized; }
 623   bool is_not_initialized() const          { return init_state() <  being_initialized; }
 624   bool is_being_initialized() const        { return init_state() == being_initialized; }
 625   bool is_in_error_state() const           { return init_state() == initialization_error; }
 626   bool is_reentrant_initialization(Thread *thread)  { return thread == _init_thread; }
 627   ClassState  init_state() const           { return AtomicAccess::load_acquire(&_init_state); }
 628   const char* init_state_name() const;
 629   bool is_rewritten() const                { return _misc_flags.rewritten(); }
 630 
 631   // is this a sealed class
 632   bool is_sealed() const;
 633 
 634   // defineClass specified verification
 635   bool should_verify_class() const         { return _misc_flags.should_verify_class(); }
 636   void set_should_verify_class(bool value) { _misc_flags.set_should_verify_class(value); }
 637 
 638   // marking
 639   bool is_marked_dependent() const         { return _misc_flags.is_marked_dependent(); }
 640   void set_is_marked_dependent(bool value) { _misc_flags.set_is_marked_dependent(value); }
 641 
 642   static ByteSize kind_offset() { return byte_offset_of(InstanceKlass, _kind); }
 643   static ByteSize misc_flags_offset() { return byte_offset_of(InstanceKlass, _misc_flags); }
 644 
 645   // initialization (virtuals from Klass)
 646   bool should_be_initialized() const override;  // means that initialize should be called
 647   void initialize_with_aot_initialized_mirror(bool early_init, TRAPS);
 648   void assert_no_clinit_will_run_for_aot_initialized_class() const NOT_DEBUG_RETURN;
 649   void initialize(TRAPS) override;
 650   void initialize_preemptable(TRAPS) override;
 651   void link_class(TRAPS);
 652   bool link_class_or_fail(TRAPS); // returns false on failure
 653   void rewrite_class(TRAPS);
 654   void link_methods(TRAPS);
 655   Method* class_initializer() const;
 656   bool interface_needs_clinit_execution_as_super(bool also_check_supers=true) const;
 657 
 658   // reference type
 659   ReferenceType reference_type() const     { return (ReferenceType)_reference_type; }
 660 
 661   bool has_acmp_maps_offset() const {
 662     return _acmp_maps_offset != 0;
 663   }
 664 
 665   int acmp_maps_offset() const {
 666     assert(_acmp_maps_offset != 0, "Not initialized");
 667     return _acmp_maps_offset;
 668   }
 669   void set_acmp_maps_offset(int offset) { _acmp_maps_offset = offset; }
 670   static ByteSize acmp_maps_offset_offset() { return byte_offset_of(InstanceKlass, _acmp_maps_offset); }
 671 
 672   // this class cp index
 673   u2 this_class_index() const             { return _this_class_index; }
 674   void set_this_class_index(u2 index)     { _this_class_index = index; }
 675 
 676   static ByteSize reference_type_offset() { return byte_offset_of(InstanceKlass, _reference_type); }
 677 
 678   // find local field, returns true if found
 679   bool find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
 680   // find field in direct superinterfaces, returns the interface in which the field is defined
 681   Klass* find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
 682   // find field according to JVM spec 5.4.3.2, returns the klass in which the field is defined
 683   Klass* find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const override;
 684   // find instance or static fields according to JVM spec 5.4.3.2, returns the klass in which the field is defined
 685   Klass* find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const;
 686 
 687   // find a non-static or static field given its offset within the class.
 688   bool contains_field_offset(int offset);
 689 
 690   bool find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const;
 691   bool find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const;
 692 
 693   bool find_local_flat_field_containing_offset(int offset, fieldDescriptor* fd) const;
 694   bool find_flat_field_containing_offset(int offset, fieldDescriptor* fd) const;
 695 
 696  private:
 697   inline static int quick_search(const Array<Method*>* methods, const Symbol* name);
 698 
 699  public:
 700   static void disable_method_binary_search() {
 701     _disable_method_binary_search = true;
 702   }
 703 
 704   // find a local method (returns null if not found)
 705   Method* find_method(const Symbol* name, const Symbol* signature) const;
 706   static Method* find_method(const Array<Method*>* methods,
 707                              const Symbol* name,
 708                              const Symbol* signature);
 709 
 710   // find a local method, but skip static methods
 711   Method* find_instance_method(const Symbol* name, const Symbol* signature,
 712                                PrivateLookupMode private_mode) const;
 713   static Method* find_instance_method(const Array<Method*>* methods,
 714                                       const Symbol* name,
 715                                       const Symbol* signature,
 716                                       PrivateLookupMode private_mode);
 717 
 718   // find a local method (returns null if not found)
 719   Method* find_local_method(const Symbol* name,
 720                             const Symbol* signature,
 721                             OverpassLookupMode overpass_mode,
 722                             StaticLookupMode static_mode,
 723                             PrivateLookupMode private_mode) const;
 724 
 725   // find a local method from given methods array (returns null if not found)
 726   static Method* find_local_method(const Array<Method*>* methods,
 727                                    const Symbol* name,
 728                                    const Symbol* signature,
 729                                    OverpassLookupMode overpass_mode,
 730                                    StaticLookupMode static_mode,
 731                                    PrivateLookupMode private_mode);
 732 
 733   // find a local method index in methods or default_methods (returns -1 if not found)
 734   static int find_method_index(const Array<Method*>* methods,
 735                                const Symbol* name,
 736                                const Symbol* signature,
 737                                OverpassLookupMode overpass_mode,
 738                                StaticLookupMode static_mode,
 739                                PrivateLookupMode private_mode);
 740 
 741   // lookup operation (returns null if not found)
 742   Method* uncached_lookup_method(const Symbol* name,
 743                                  const Symbol* signature,
 744                                  OverpassLookupMode overpass_mode,
 745                                  PrivateLookupMode private_mode = PrivateLookupMode::find) const override;
 746 
 747   // lookup a method in all the interfaces that this class implements
 748   // (returns null if not found)
 749   Method* lookup_method_in_all_interfaces(Symbol* name, Symbol* signature, DefaultsLookupMode defaults_mode) const;
 750 
 751   // lookup a method in local defaults then in all interfaces
 752   // (returns null if not found)
 753   Method* lookup_method_in_ordered_interfaces(Symbol* name, Symbol* signature) const;
 754 
 755   // Find method indices by name.  If a method with the specified name is
 756   // found the index to the first method is returned, and 'end' is filled in
 757   // with the index of first non-name-matching method.  If no method is found
 758   // -1 is returned.
 759   int find_method_by_name(const Symbol* name, int* end) const;
 760   static int find_method_by_name(const Array<Method*>* methods,
 761                                  const Symbol* name, int* end);
 762 
 763   // constant pool
 764   ConstantPool* constants() const        { return _constants; }
 765   void set_constants(ConstantPool* c)    { _constants = c; }
 766 
 767   // protection domain
 768   oop protection_domain() const override;
 769 
 770   // signers
 771   objArrayOop signers() const;
 772 
 773   bool is_contended() const                { return _misc_flags.is_contended(); }
 774   void set_is_contended(bool value)        { _misc_flags.set_is_contended(value); }
 775 
 776   // source file name
 777   Symbol* source_file_name() const;
 778   u2 source_file_name_index() const;
 779   void set_source_file_name_index(u2 sourcefile_index);
 780 
 781   // minor and major version numbers of class file
 782   u2 minor_version() const;
 783   void set_minor_version(u2 minor_version);
 784   u2 major_version() const;
 785   void set_major_version(u2 major_version);
 786 
 787   bool supports_inline_types() const;
 788 
 789   // source debug extension
 790   const char* source_debug_extension() const { return _source_debug_extension; }
 791   void set_source_debug_extension(const char* array, int length);
 792 
 793   // nonstatic oop-map blocks
 794   static int nonstatic_oop_map_size(unsigned int oop_map_count) {
 795     return oop_map_count * OopMapBlock::size_in_words();
 796   }
 797   unsigned int nonstatic_oop_map_count() const {
 798     return _nonstatic_oop_map_size / OopMapBlock::size_in_words();
 799   }
 800   int nonstatic_oop_map_size() const { return _nonstatic_oop_map_size; }
 801   void set_nonstatic_oop_map_size(int words) {
 802     _nonstatic_oop_map_size = words;
 803   }
 804 
 805   bool has_contended_annotations() const { return _misc_flags.has_contended_annotations(); }
 806   void set_has_contended_annotations(bool value)  { _misc_flags.set_has_contended_annotations(value); }
 807 
 808 #if INCLUDE_JVMTI
 809   // Redefinition locking.  Class can only be redefined by one thread at a time.
 810   bool is_being_redefined() const          { return _misc_flags.is_being_redefined(); }
 811   void set_is_being_redefined(bool value)  { _misc_flags.set_is_being_redefined(value); }
 812 
 813   // RedefineClasses() support for previous versions:
 814   void add_previous_version(InstanceKlass* ik, int emcp_method_count);
 815   void purge_previous_version_list();
 816 
 817   InstanceKlass* previous_versions() const { return _previous_versions; }
 818 #else
 819   InstanceKlass* previous_versions() const { return nullptr; }
 820 #endif
 821 
 822   const InstanceKlass* get_klass_version(int version) const;
 823 
 824   bool has_been_redefined() const { return _misc_flags.has_been_redefined(); }
 825   void set_has_been_redefined() { _misc_flags.set_has_been_redefined(true); }
 826 
 827   bool is_scratch_class() const { return _misc_flags.is_scratch_class(); }
 828   void set_is_scratch_class() { _misc_flags.set_is_scratch_class(true); }
 829 
 830   bool has_resolved_methods() const { return _misc_flags.has_resolved_methods(); }
 831   void set_has_resolved_methods()   { _misc_flags.set_has_resolved_methods(true); }
 832   void set_has_resolved_methods(bool value)   { _misc_flags.set_has_resolved_methods(value); }
 833 
 834 public:
 835 #if INCLUDE_JVMTI
 836 
 837   void init_previous_versions() {
 838     _previous_versions = nullptr;
 839   }
 840 
 841  private:
 842   static bool  _should_clean_previous_versions;
 843  public:
 844   static void purge_previous_versions(InstanceKlass* ik) {
 845     if (ik->has_been_redefined()) {
 846       ik->purge_previous_version_list();
 847     }
 848   }
 849 
 850   static bool should_clean_previous_versions_and_reset();
 851   static bool should_clean_previous_versions() { return _should_clean_previous_versions; }
 852 
 853   // JVMTI: Support for caching a class file before it is modified by an agent that can do retransformation
 854   void set_cached_class_file(JvmtiCachedClassFileData *data) {
 855     _cached_class_file = data;
 856   }
 857   JvmtiCachedClassFileData * get_cached_class_file();
 858   jint get_cached_class_file_len();
 859   unsigned char * get_cached_class_file_bytes();
 860 
 861   // JVMTI: Support for caching of field indices, types, and offsets
 862   void set_jvmti_cached_class_field_map(JvmtiCachedClassFieldMap* descriptor) {
 863     _jvmti_cached_class_field_map = descriptor;
 864   }
 865   JvmtiCachedClassFieldMap* jvmti_cached_class_field_map() const {
 866     return _jvmti_cached_class_field_map;
 867   }
 868 #else // INCLUDE_JVMTI
 869 
 870   static void purge_previous_versions(InstanceKlass* ik) { return; };
 871   static bool should_clean_previous_versions_and_reset() { return false; }
 872 
 873   void set_cached_class_file(JvmtiCachedClassFileData *data) {
 874     assert(data == nullptr, "unexpected call with JVMTI disabled");
 875   }
 876   JvmtiCachedClassFileData * get_cached_class_file() { return (JvmtiCachedClassFileData *)nullptr; }
 877 
 878 #endif // INCLUDE_JVMTI
 879 
 880   bool has_nonstatic_concrete_methods() const { return _misc_flags.has_nonstatic_concrete_methods(); }
 881   void set_has_nonstatic_concrete_methods(bool b) { _misc_flags.set_has_nonstatic_concrete_methods(b); }
 882 
 883   bool declares_nonstatic_concrete_methods() const { return _misc_flags.declares_nonstatic_concrete_methods(); }
 884   void set_declares_nonstatic_concrete_methods(bool b) { _misc_flags.set_declares_nonstatic_concrete_methods(b); }
 885 
 886   bool has_miranda_methods () const     { return _misc_flags.has_miranda_methods(); }
 887   void set_has_miranda_methods()        { _misc_flags.set_has_miranda_methods(true); }
 888   bool has_final_method() const         { return _misc_flags.has_final_method(); }
 889   void set_has_final_method()           { _misc_flags.set_has_final_method(true); }
 890 
 891   // for adding methods, ConstMethod::UNSET_IDNUM means no more ids available
 892   inline u2 next_method_idnum();
 893   void set_initial_method_idnum(u2 value)             { _idnum_allocated_count = value; }
 894 
 895   // runtime support for strict statics
 896   bool has_strict_static_fields() const     { return _misc_flags.has_strict_static_fields(); }
 897   void set_has_strict_static_fields(bool b) { _misc_flags.set_has_strict_static_fields(b); }
 898   void notify_strict_static_access(int field_index, bool is_writing, TRAPS);
 899   const char* format_strict_static_message(Symbol* field_name, const char* doing_what = nullptr);
 900   void throw_strict_static_exception(Symbol* field_name, const char* when, TRAPS);
 901 
 902   // generics support
 903   Symbol* generic_signature() const;
 904   u2 generic_signature_index() const;
 905   void set_generic_signature_index(u2 sig_index);
 906 
 907   u2 enclosing_method_data(int offset) const;
 908   u2 enclosing_method_class_index() const {
 909     return enclosing_method_data(enclosing_method_class_index_offset);
 910   }
 911   u2 enclosing_method_method_index() {
 912     return enclosing_method_data(enclosing_method_method_index_offset);
 913   }
 914   void set_enclosing_method_indices(u2 class_index,
 915                                     u2 method_index);
 916 
 917   // jmethodID support
 918   jmethodID get_jmethod_id(Method* method);
 919   void make_methods_jmethod_ids();
 920   jmethodID jmethod_id_or_null(Method* method);
 921   void update_methods_jmethod_cache();
 922 
 923   // annotations support
 924   Annotations* annotations() const          { return _annotations; }
 925   void set_annotations(Annotations* anno)   { _annotations = anno; }
 926 
 927   AnnotationArray* class_annotations() const {
 928     return (_annotations != nullptr) ? _annotations->class_annotations() : nullptr;
 929   }
 930   Array<AnnotationArray*>* fields_annotations() const {
 931     return (_annotations != nullptr) ? _annotations->fields_annotations() : nullptr;
 932   }
 933   AnnotationArray* class_type_annotations() const {
 934     return (_annotations != nullptr) ? _annotations->class_type_annotations() : nullptr;
 935   }
 936   Array<AnnotationArray*>* fields_type_annotations() const {
 937     return (_annotations != nullptr) ? _annotations->fields_type_annotations() : nullptr;
 938   }
 939   // allocation
 940   instanceOop allocate_instance(TRAPS);
 941   static instanceOop allocate_instance(oop cls, TRAPS);
 942 
 943   // additional member function to return a handle
 944   instanceHandle allocate_instance_handle(TRAPS);
 945 
 946   // Helper function
 947   static instanceOop register_finalizer(instanceOop i, TRAPS);
 948 
 949   // Check whether reflection/jni/jvm code is allowed to instantiate this class;
 950   // if not, throw either an Error or an Exception.
 951   void check_valid_for_instantiation(bool throwError, TRAPS) override;
 952 
 953   // initialization
 954   void call_class_initializer(TRAPS);
 955   void set_initialization_state_and_notify(ClassState state, TRAPS);
 956 
 957   // OopMapCache support
 958   OopMapCache* oop_map_cache()               { return _oop_map_cache; }
 959   void set_oop_map_cache(OopMapCache *cache) { _oop_map_cache = cache; }
 960   void mask_for(const methodHandle& method, int bci, InterpreterOopMap* entry);
 961 
 962   // JNI identifier support (for static fields - for jni performance)
 963   JNIid* jni_ids()                               { return _jni_ids; }
 964   void set_jni_ids(JNIid* ids)                   { _jni_ids = ids; }
 965   JNIid* jni_id_for(int offset);
 966 
 967  public:
 968   // maintenance of deoptimization dependencies
 969   inline DependencyContext dependencies();
 970   void mark_dependent_nmethods(DeoptimizationScope* deopt_scope, KlassDepChange& changes);
 971   void add_dependent_nmethod(nmethod* nm);
 972   void clean_dependency_context();
 973   // Setup link to hierarchy and deoptimize
 974   void add_to_hierarchy(JavaThread* current);
 975 
 976   // On-stack replacement support
 977   nmethod* osr_nmethods_head() const         { return _osr_nmethods_head; };
 978   void set_osr_nmethods_head(nmethod* h)     { _osr_nmethods_head = h; };
 979   void add_osr_nmethod(nmethod* n);
 980   bool remove_osr_nmethod(nmethod* n);
 981   int mark_osr_nmethods(DeoptimizationScope* deopt_scope, const Method* m);
 982   nmethod* lookup_osr_nmethod(const Method* m, int bci, int level, bool match_level) const;
 983 
 984 #if INCLUDE_JVMTI
 985   // Breakpoint support (see methods on Method* for details)
 986   BreakpointInfo* breakpoints() const       { return _breakpoints; };
 987   void set_breakpoints(BreakpointInfo* bps) { _breakpoints = bps; };
 988 #endif
 989 
 990   // support for stub routines
 991   static ByteSize init_state_offset()  { return byte_offset_of(InstanceKlass, _init_state); }
 992   JFR_ONLY(DEFINE_KLASS_TRACE_ID_OFFSET;)
 993   static ByteSize init_thread_offset() { return byte_offset_of(InstanceKlass, _init_thread); }
 994 
 995   static ByteSize inline_layout_info_array_offset() { return byte_offset_of(InstanceKlass, _inline_layout_info_array); }
 996   static ByteSize adr_inline_klass_members_offset() { return byte_offset_of(InstanceKlass, _adr_inline_klass_members); }
 997 
 998   // subclass/subinterface checks
 999   bool implements_interface(Klass* k) const;
1000   bool is_same_or_direct_interface(Klass* k) const;
1001 
1002 #ifdef ASSERT
1003   // check whether this class or one of its superclasses was redefined
1004   bool has_redefined_this_or_super() const;
1005 #endif
1006 
1007   // Access to the implementor of an interface.
1008   InstanceKlass* implementor() const;
1009   void set_implementor(InstanceKlass* ik);
1010   int  nof_implementors() const;
1011   void add_implementor(InstanceKlass* ik);  // ik is a new class that implements this interface
1012   void init_implementor();           // initialize
1013 
1014  private:
1015   // link this class into the implementors list of every interface it implements
1016   void process_interfaces();
1017 
1018  public:
1019   // virtual operations from Klass
1020   GrowableArray<Klass*>* compute_secondary_supers(int num_extra_slots,
1021                                                   Array<InstanceKlass*>* transitive_interfaces) override;
1022   bool can_be_primary_super_slow() const override;
1023   size_t oop_size(oop obj)  const override    { return size_helper(); }
1024   // slow because it's a virtual call and used for verifying the layout_helper.
1025   // Using the layout_helper bits, we can call is_instance_klass without a virtual call.
1026   DEBUG_ONLY(bool is_instance_klass_slow() const override { return true; })
1027 
1028   // Iterators
1029   void do_local_static_fields(FieldClosure* cl);
1030   void do_nonstatic_fields(FieldClosure* cl); // including inherited fields
1031   void do_local_static_fields(void f(fieldDescriptor*, Handle, TRAPS), Handle, TRAPS);
1032   void print_nonstatic_fields(FieldClosure* cl); // including inherited and injected fields
1033 
1034   void methods_do(void f(Method* method));
1035 
1036   static InstanceKlass* cast(Klass* k) {
1037     return const_cast<InstanceKlass*>(cast(const_cast<const Klass*>(k)));
1038   }
1039 
1040   static const InstanceKlass* cast(const Klass* k) {
1041     assert(k != nullptr, "k should not be null");
1042     assert(k->is_instance_klass(), "cast to InstanceKlass");
1043     return static_cast<const InstanceKlass*>(k);
1044   }
1045 
1046   // This hides Klass::super(). The _super of an InstanceKlass is
1047   // always an InstanceKlass (or nullptr)
1048   InstanceKlass* super() const {
1049     return (Klass::super() == nullptr) ? nullptr : InstanceKlass::cast(Klass::super());
1050   }
1051 
1052   InstanceKlass* java_super() const override {
1053     return InstanceKlass::super();
1054   }
1055 
1056   // Sizing (in words)
1057   static int header_size() { return sizeof(InstanceKlass) / wordSize; }
1058 
1059   static int size(int vtable_length,
1060                   int itable_length,
1061                   int nonstatic_oop_map_size,
1062                   bool is_interface,
1063                   bool is_inline_type);
1064 
1065   int size() const override;
1066 
1067 
1068   inline intptr_t* start_of_itable() const;
1069   inline intptr_t* end_of_itable() const;
1070   inline oop static_field_base_raw();
1071   bool bounds_check(address addr, bool edge_ok = false, intptr_t size_in_bytes = -1) const PRODUCT_RETURN0;
1072 
1073   inline OopMapBlock* start_of_nonstatic_oop_maps() const;
1074   inline Klass** end_of_nonstatic_oop_maps() const;
1075 
1076   inline InstanceKlass* volatile* adr_implementor() const;
1077 
1078   // The end of the memory block that belongs to this InstanceKlass.
1079   // Sub-klasses can place their fields after this address.
1080   inline address end_of_instance_klass() const;
1081 
1082   void set_inline_layout_info_array(Array<InlineLayoutInfo>* array) { _inline_layout_info_array = array; }
1083   Array<InlineLayoutInfo>* inline_layout_info_array() const { return _inline_layout_info_array; }
1084 
1085   InlineLayoutInfo inline_layout_info(int index) const {
1086     assert(_inline_layout_info_array != nullptr, "Array not created");
1087     return _inline_layout_info_array->at(index);
1088   }
1089 
1090   InlineLayoutInfo* inline_layout_info_adr(int index) {
1091     assert(_inline_layout_info_array != nullptr, "Array not created");
1092     return _inline_layout_info_array->adr_at(index);
1093   }
1094 
1095   inline InlineKlass* get_inline_type_field_klass(int idx) const ;
1096   inline InlineKlass* get_inline_type_field_klass_or_null(int idx) const;
1097 
1098   // Use this to return the size of an instance in heap words:
1099   int size_helper() const {
1100     return layout_helper_to_size_helper(layout_helper());
1101   }
1102 
1103   // This bit is initialized in classFileParser.cpp.
1104   // It is false under any of the following conditions:
1105   //  - the class is abstract (including any interface)
1106   //  - the class size is larger than FastAllocateSizeLimit
1107   //  - the class is java/lang/Class, which cannot be allocated directly
1108   bool can_be_fastpath_allocated() const {
1109     return !layout_helper_needs_slow_path(layout_helper());
1110   }
1111 
1112   // Java itable
1113   klassItable itable() const;        // return klassItable wrapper
1114   Method* method_at_itable(InstanceKlass* holder, int index, TRAPS);
1115   Method* method_at_itable_or_null(InstanceKlass* holder, int index, bool& itable_entry_found);
1116   int vtable_index_of_interface_method(Method* method);
1117 
1118 #if INCLUDE_JVMTI
1119   void adjust_default_methods(bool* trace_name_printed);
1120 #endif // INCLUDE_JVMTI
1121 
1122   void clean_weak_instanceklass_links();
1123  private:
1124   void clean_implementors_list();
1125   void clean_method_data();
1126 
1127  public:
1128   // Explicit metaspace deallocation of fields
1129   // For RedefineClasses and class file parsing errors, we need to deallocate
1130   // instanceKlasses and the metadata they point to.
1131   void deallocate_contents(ClassLoaderData* loader_data);
1132   static void deallocate_methods(ClassLoaderData* loader_data,
1133                                  Array<Method*>* methods);
1134   void static deallocate_interfaces(ClassLoaderData* loader_data,
1135                                     const InstanceKlass* super_klass,
1136                                     Array<InstanceKlass*>* local_interfaces,
1137                                     Array<InstanceKlass*>* transitive_interfaces);
1138   void static deallocate_record_components(ClassLoaderData* loader_data,
1139                                            Array<RecordComponent*>* record_component);
1140 
1141   bool on_stack() const override;
1142 
1143   // callbacks for actions during class unloading
1144   static void unload_class(InstanceKlass* ik);
1145 
1146   void release_C_heap_structures(bool release_sub_metadata = true) override;
1147 
1148   // Naming
1149   const char* signature_name() const override;
1150   const char* signature_name_of_carrier(char c) const;
1151 
1152   // Oop fields (and metadata) iterators
1153   //
1154   // The InstanceKlass iterators also visits the Object's klass.
1155 
1156   // Forward iteration
1157  public:
1158   // Iterate over all oop fields in the oop maps.
1159   template <typename T, class OopClosureType>
1160   inline void oop_oop_iterate_oop_maps(oop obj, OopClosureType* closure);
1161 
1162   // Iterate over all oop fields and metadata.
1163   template <typename T, class OopClosureType>
1164   inline void oop_oop_iterate(oop obj, OopClosureType* closure);
1165 
1166   // Iterate over all oop fields in one oop map.
1167   template <typename T, class OopClosureType>
1168   inline void oop_oop_iterate_oop_map(OopMapBlock* map, oop obj, OopClosureType* closure);
1169 
1170 
1171   // Reverse iteration
1172   // Iterate over all oop fields and metadata.
1173   template <typename T, class OopClosureType>
1174   inline void oop_oop_iterate_reverse(oop obj, OopClosureType* closure);
1175 
1176  private:
1177   // Iterate over all oop fields in the oop maps.
1178   template <typename T, class OopClosureType>
1179   inline void oop_oop_iterate_oop_maps_reverse(oop obj, OopClosureType* closure);
1180 
1181   // Iterate over all oop fields in one oop map.
1182   template <typename T, class OopClosureType>
1183   inline void oop_oop_iterate_oop_map_reverse(OopMapBlock* map, oop obj, OopClosureType* closure);
1184 
1185 
1186   // Bounded range iteration
1187  public:
1188   // Iterate over all oop fields in the oop maps.
1189   template <typename T, class OopClosureType>
1190   inline void oop_oop_iterate_oop_maps_bounded(oop obj, OopClosureType* closure, MemRegion mr);
1191 
1192   // Iterate over all oop fields and metadata.
1193   template <typename T, class OopClosureType>
1194   inline void oop_oop_iterate_bounded(oop obj, OopClosureType* closure, MemRegion mr);
1195 
1196  private:
1197   // Iterate over all oop fields in one oop map.
1198   template <typename T, class OopClosureType>
1199   inline void oop_oop_iterate_oop_map_bounded(OopMapBlock* map, oop obj, OopClosureType* closure, MemRegion mr);
1200 
1201 
1202  public:
1203   u2 idnum_allocated_count() const      { return _idnum_allocated_count; }
1204 
1205 private:
1206   // initialization state
1207   void set_init_state(ClassState state);
1208   void set_rewritten()                  { _misc_flags.set_rewritten(true); }
1209   void set_init_thread(JavaThread *thread)  {
1210     assert((thread == JavaThread::current() && _init_thread == nullptr) ||
1211            (thread == nullptr && _init_thread == JavaThread::current()), "Only one thread is allowed to own initialization");
1212     AtomicAccess::store(&_init_thread, thread);
1213   }
1214 
1215   jmethodID* methods_jmethod_ids_acquire() const;
1216   void release_set_methods_jmethod_ids(jmethodID* jmeths);
1217   // This nulls out obsolete jmethodIDs for all methods in 'klass'.
1218   static void clear_obsolete_jmethod_ids(InstanceKlass* klass);
1219   jmethodID update_jmethod_id(jmethodID* jmeths, Method* method, int idnum);
1220 
1221 public:
1222   // Lock for (1) initialization; (2) access to the ConstantPool of this class.
1223   // Must be one per class and it has to be a VM internal object so java code
1224   // cannot lock it (like the mirror).
1225   // It has to be an object not a Mutex because it's held through java calls.
1226   oop init_lock() const;
1227 
1228   // Returns the array class for the n'th dimension
1229   ArrayKlass* array_klass(int n, TRAPS) override;
1230   ArrayKlass* array_klass_or_null(int n) override;
1231 
1232   // Returns the array class with this class as element type
1233   ArrayKlass* array_klass(TRAPS) override;
1234   ArrayKlass* array_klass_or_null() override;
1235 
1236   static void clean_initialization_error_table();
1237 private:
1238   void fence_and_clear_init_lock();
1239 
1240   bool link_class_impl                           (TRAPS);
1241   bool verify_code                               (TRAPS);
1242   void initialize_impl                           (TRAPS);
1243   void initialize_super_interfaces               (TRAPS);
1244 
1245   void add_initialization_error(JavaThread* current, Handle exception);
1246   oop get_initialization_error(JavaThread* current);
1247 
1248   // find a local method (returns null if not found)
1249   Method* find_method_impl(const Symbol* name,
1250                            const Symbol* signature,
1251                            OverpassLookupMode overpass_mode,
1252                            StaticLookupMode static_mode,
1253                            PrivateLookupMode private_mode) const;
1254 
1255   static Method* find_method_impl(const Array<Method*>* methods,
1256                                   const Symbol* name,
1257                                   const Symbol* signature,
1258                                   OverpassLookupMode overpass_mode,
1259                                   StaticLookupMode static_mode,
1260                                   PrivateLookupMode private_mode);
1261 
1262 #if INCLUDE_JVMTI
1263   // RedefineClasses support
1264   void link_previous_versions(InstanceKlass* pv) { _previous_versions = pv; }
1265   void mark_newly_obsolete_methods(Array<Method*>* old_methods, int emcp_method_count);
1266 #endif
1267 public:
1268 
1269 #if INCLUDE_CDS
1270   // CDS support - remove and restore oops from metadata. Oops are not shared.
1271   void remove_unshareable_info() override;
1272   void remove_unshareable_flags();
1273   void remove_java_mirror() override;
1274   virtual void restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, PackageEntry* pkg_entry, TRAPS);
1275   void init_shared_package_entry();
1276   bool can_be_verified_at_dumptime() const;
1277   void compute_has_loops_flag_for_methods();
1278 #endif
1279   bool     has_init_deps_processed() const { return _misc_flags.has_init_deps_processed(); }
1280   void set_has_init_deps_processed() {
1281     assert(is_initialized(), "");
1282     assert(!has_init_deps_processed(), "already set"); // one-off action
1283     _misc_flags.set_has_init_deps_processed(true);
1284   }
1285 
1286   u2 compute_modifier_flags() const override;
1287 
1288 public:
1289   // JVMTI support
1290   jint jvmti_class_status() const override;
1291 
1292   void metaspace_pointers_do(MetaspaceClosure* iter) override;
1293 
1294  public:
1295   // Printing
1296   void print_on(outputStream* st) const override;
1297   void print_value_on(outputStream* st) const override;
1298   void print_class_flags(outputStream* st) const;
1299 
1300   void oop_print_value_on(oop obj, outputStream* st) override;
1301 
1302   void oop_print_on      (oop obj, outputStream* st) override { oop_print_on(obj, st, 0, 0); }
1303   void oop_print_on      (oop obj, outputStream* st, int indent = 0, int base_offset = 0);
1304 
1305 #ifndef PRODUCT
1306   void print_dependent_nmethods(bool verbose = false);
1307   bool is_dependent_nmethod(nmethod* nm);
1308   bool verify_itable_index(int index);
1309 #endif
1310 
1311   const char* internal_name() const override;
1312 
1313   template<typename T, typename TClosureType>
1314   static void print_array_on(outputStream* st, Array<T>* array, TClosureType elem_printer);
1315 
1316   // Verification
1317   void verify_on(outputStream* st) override;
1318 
1319   void oop_verify_on(oop obj, outputStream* st) override;
1320 
1321   // Logging
1322   void print_class_load_logging(ClassLoaderData* loader_data,
1323                                 const ModuleEntry* module_entry,
1324                                 const ClassFileStream* cfs) const;
1325  private:
1326   void print_class_load_cause_logging() const;
1327   void print_class_load_helper(ClassLoaderData* loader_data,
1328                                const ModuleEntry* module_entry,
1329                                const ClassFileStream* cfs) const;
1330 };
1331 
1332 // for adding methods
1333 // UNSET_IDNUM return means no more ids available
1334 inline u2 InstanceKlass::next_method_idnum() {
1335   if (_idnum_allocated_count == ConstMethod::MAX_IDNUM) {
1336     return ConstMethod::UNSET_IDNUM; // no more ids available
1337   } else {
1338     return _idnum_allocated_count++;
1339   }
1340 }
1341 
1342 class PrintClassClosure : public KlassClosure {
1343 private:
1344   outputStream* _st;
1345   bool _verbose;
1346 public:
1347   PrintClassClosure(outputStream* st, bool verbose);
1348 
1349   void do_klass(Klass* k);
1350 };
1351 
1352 /* JNIid class for jfieldIDs only */
1353 class JNIid: public CHeapObj<mtClass> {
1354   friend class VMStructs;
1355  private:
1356   InstanceKlass*     _holder;
1357   JNIid*             _next;
1358   int                _offset;
1359 #ifdef ASSERT
1360   bool               _is_static_field_id;
1361 #endif
1362 
1363  public:
1364   // Accessors
1365   InstanceKlass* holder() const   { return _holder; }
1366   int offset() const              { return _offset; }
1367   JNIid* next()                   { return _next; }
1368   // Constructor
1369   JNIid(InstanceKlass* holder, int offset, JNIid* next);
1370   // Identifier lookup
1371   JNIid* find(int offset);
1372 
1373   bool find_local_field(fieldDescriptor* fd) {
1374     return InstanceKlass::cast(holder())->find_local_field_from_offset(offset(), true, fd);
1375   }
1376 
1377   static void deallocate(JNIid* id);
1378   // Debugging
1379 #ifdef ASSERT
1380   bool is_static_field_id() const { return _is_static_field_id; }
1381   void set_is_static_field_id()   { _is_static_field_id = true; }
1382 #endif
1383   void verify(InstanceKlass* holder);
1384 };
1385 
1386 // An iterator that's used to access the inner classes indices in the
1387 // InstanceKlass::_inner_classes array.
1388 class InnerClassesIterator : public StackObj {
1389  private:
1390   Array<jushort>* _inner_classes;
1391   int _length;
1392   int _idx;
1393  public:
1394 
1395   InnerClassesIterator(const InstanceKlass* k) {
1396     _inner_classes = k->inner_classes();
1397     if (k->inner_classes() != nullptr) {
1398       _length = _inner_classes->length();
1399       // The inner class array's length should be the multiple of
1400       // inner_class_next_offset if it only contains the InnerClasses
1401       // attribute data, or it should be
1402       // n*inner_class_next_offset+enclosing_method_attribute_size
1403       // if it also contains the EnclosingMethod data.
1404       assert((_length % InstanceKlass::inner_class_next_offset == 0 ||
1405               _length % InstanceKlass::inner_class_next_offset == InstanceKlass::enclosing_method_attribute_size),
1406              "just checking");
1407       // Remove the enclosing_method portion if exists.
1408       if (_length % InstanceKlass::inner_class_next_offset == InstanceKlass::enclosing_method_attribute_size) {
1409         _length -= InstanceKlass::enclosing_method_attribute_size;
1410       }
1411     } else {
1412       _length = 0;
1413     }
1414     _idx = 0;
1415   }
1416 
1417   int length() const {
1418     return _length;
1419   }
1420 
1421   void next() {
1422     _idx += InstanceKlass::inner_class_next_offset;
1423   }
1424 
1425   bool done() const {
1426     return (_idx >= _length);
1427   }
1428 
1429   u2 inner_class_info_index() const {
1430     return _inner_classes->at(
1431                _idx + InstanceKlass::inner_class_inner_class_info_offset);
1432   }
1433 
1434   void set_inner_class_info_index(u2 index) {
1435     _inner_classes->at_put(
1436                _idx + InstanceKlass::inner_class_inner_class_info_offset, index);
1437   }
1438 
1439   u2 outer_class_info_index() const {
1440     return _inner_classes->at(
1441                _idx + InstanceKlass::inner_class_outer_class_info_offset);
1442   }
1443 
1444   void set_outer_class_info_index(u2 index) {
1445     _inner_classes->at_put(
1446                _idx + InstanceKlass::inner_class_outer_class_info_offset, index);
1447   }
1448 
1449   u2 inner_name_index() const {
1450     return _inner_classes->at(
1451                _idx + InstanceKlass::inner_class_inner_name_offset);
1452   }
1453 
1454   void set_inner_name_index(u2 index) {
1455     _inner_classes->at_put(
1456                _idx + InstanceKlass::inner_class_inner_name_offset, index);
1457   }
1458 
1459   u2 inner_access_flags() const {
1460     return _inner_classes->at(
1461                _idx + InstanceKlass::inner_class_access_flags_offset);
1462   }
1463 };
1464 
1465 // Iterator over class hierarchy under a particular class. Implements depth-first pre-order traversal.
1466 // Usage:
1467 //  for (ClassHierarchyIterator iter(root_klass); !iter.done(); iter.next()) {
1468 //    Klass* k = iter.klass();
1469 //    ...
1470 //  }
1471 class ClassHierarchyIterator : public StackObj {
1472  private:
1473   InstanceKlass* _root;
1474   Klass*         _current;
1475   bool           _visit_subclasses;
1476 
1477  public:
1478   ClassHierarchyIterator(InstanceKlass* root) : _root(root), _current(root), _visit_subclasses(true) {
1479     assert(_root == _current, "required"); // initial state
1480   }
1481 
1482   bool done() {
1483     return (_current == nullptr);
1484   }
1485 
1486   // Make a step iterating over the class hierarchy under the root class.
1487   // Skips subclasses if requested.
1488   void next();
1489 
1490   Klass* klass() {
1491     assert(!done(), "sanity");
1492     return _current;
1493   }
1494 
1495   // Skip subclasses of the current class.
1496   void skip_subclasses() {
1497     _visit_subclasses = false;
1498   }
1499 };
1500 
1501 #endif // SHARE_OOPS_INSTANCEKLASS_HPP