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