1 /*
   2  * Copyright (c) 1997, 2025, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef SHARE_OOPS_INSTANCEKLASS_HPP
  26 #define SHARE_OOPS_INSTANCEKLASS_HPP
  27 
  28 #include "code/vmreg.hpp"
  29 #include "memory/allocation.hpp"
  30 #include "memory/referenceType.hpp"
  31 #include "oops/annotations.hpp"
  32 #include "oops/constMethod.hpp"
  33 #include "oops/fieldInfo.hpp"
  34 #include "oops/instanceKlassFlags.hpp"
  35 #include "oops/instanceOop.hpp"
  36 #include "oops/refArrayKlass.hpp"
  37 #include "runtime/handles.hpp"
  38 #include "runtime/javaThread.hpp"
  39 #include "utilities/accessFlags.hpp"
  40 #include "utilities/align.hpp"
  41 #include "utilities/growableArray.hpp"
  42 #include "utilities/macros.hpp"
  43 #if INCLUDE_JFR
  44 #include "jfr/support/jfrKlassExtension.hpp"
  45 #endif
  46 
  47 class ConstantPool;
  48 class DeoptimizationScope;
  49 class klassItable;
  50 class RecordComponent;
  51 
  52 // An InstanceKlass is the VM level representation of a Java class.
  53 // It contains all information needed for at class at execution runtime.
  54 
  55 //  InstanceKlass embedded field layout (after declared fields):
  56 //    [EMBEDDED Java vtable             ] size in words = vtable_len
  57 //    [EMBEDDED nonstatic oop-map blocks] size in words = nonstatic_oop_map_size
  58 //      The embedded nonstatic oop-map blocks are short pairs (offset, length)
  59 //      indicating where oops are located in instances of this klass.
  60 //    [EMBEDDED implementor of the interface] only exist for interface
  61 //    [EMBEDDED InlineKlassFixedBlock] only if is an InlineKlass instance
  62 
  63 
  64 // forward declaration for class -- see below for definition
  65 #if INCLUDE_JVMTI
  66 class BreakpointInfo;
  67 #endif
  68 class ClassFileParser;
  69 class ClassFileStream;
  70 class KlassDepChange;
  71 class DependencyContext;
  72 class fieldDescriptor;
  73 class JNIid;
  74 class JvmtiCachedClassFieldMap;
  75 class nmethodBucket;
  76 class OopMapCache;
  77 class BufferedInlineTypeBlob;
  78 class InterpreterOopMap;
  79 class PackageEntry;
  80 class ModuleEntry;
  81 
  82 // This is used in iterators below.
  83 class FieldClosure: public StackObj {
  84 public:
  85   virtual void do_field(fieldDescriptor* fd) = 0;
  86 };
  87 
  88 // Print fields.
  89 // If "obj" argument to constructor is null, prints static fields, otherwise prints non-static fields.
  90 class FieldPrinter: public FieldClosure {
  91    oop _obj;
  92    outputStream* _st;
  93    int _indent;
  94    int _base_offset;
  95  public:
  96    FieldPrinter(outputStream* st, oop obj = nullptr, int indent = 0, int base_offset = 0) :
  97                  _obj(obj), _st(st), _indent(indent), _base_offset(base_offset) {}
  98    void do_field(fieldDescriptor* fd);
  99 };
 100 
 101 // Describes where oops are located in instances of this klass.
 102 class OopMapBlock {
 103  public:
 104   // Byte offset of the first oop mapped by this block.
 105   int offset() const          { return _offset; }
 106   void set_offset(int offset) { _offset = offset; }
 107 
 108   // Number of oops in this block.
 109   uint count() const         { return _count; }
 110   void set_count(uint count) { _count = count; }
 111 
 112   void increment_count(int diff) { _count += diff; }
 113 
 114   int offset_span() const { return _count * heapOopSize; }
 115 
 116   int end_offset() const {
 117     return offset() + offset_span();
 118   }
 119 
 120   bool is_contiguous(int another_offset) const {
 121     return another_offset == end_offset();
 122   }
 123 
 124   // sizeof(OopMapBlock) in words.
 125   static int size_in_words() {
 126     return align_up((int)sizeof(OopMapBlock), wordSize) >>
 127       LogBytesPerWord;
 128   }
 129 
 130   static int compare_offset(const OopMapBlock* a, const OopMapBlock* b) {
 131     return a->offset() - b->offset();
 132   }
 133 
 134  private:
 135   int  _offset;
 136   uint _count;
 137 };
 138 
 139 struct JvmtiCachedClassFileData;
 140 
 141 class SigEntry;
 142 
 143 class InlineKlassFixedBlock {
 144   Array<SigEntry>** _extended_sig;
 145   Array<VMRegPair>** _return_regs;
 146   address* _pack_handler;
 147   address* _pack_handler_jobject;
 148   address* _unpack_handler;
 149   int* _null_reset_value_offset;
 150   int _payload_offset;          // offset of the begining of the payload in a heap buffered instance
 151   int _payload_size_in_bytes;   // size of payload layout
 152   int _payload_alignment;       // alignment required for payload
 153   int _non_atomic_size_in_bytes; // size of null-free non-atomic flat layout
 154   int _non_atomic_alignment;    // alignment requirement for null-free non-atomic layout
 155   int _atomic_size_in_bytes;    // size and alignment requirement for a null-free atomic layout, -1 if no atomic flat layout is possible
 156   int _nullable_size_in_bytes;  // size and alignment requirement for a nullable layout (always atomic), -1 if no nullable flat layout is possible
 157   int _null_marker_offset;      // expressed as an offset from the beginning of the object for a heap buffered value
 158                                 // payload_offset must be subtracted to get the offset from the beginning of the payload
 159 
 160   friend class InlineKlass;
 161 };
 162 
 163 class InlineLayoutInfo : public MetaspaceObj {
 164   InlineKlass* _klass;
 165   LayoutKind _kind;
 166   int _null_marker_offset; // null marker offset for this field, relative to the beginning of the current container
 167 
 168  public:
 169   InlineLayoutInfo(): _klass(nullptr), _kind(LayoutKind::UNKNOWN), _null_marker_offset(-1)  {}
 170   InlineLayoutInfo(InlineKlass* ik, LayoutKind kind, int size, int nm_offset):
 171     _klass(ik), _kind(kind), _null_marker_offset(nm_offset) {}
 172 
 173   InlineKlass* klass() const { return _klass; }
 174   void set_klass(InlineKlass* k) { _klass = k; }
 175 
 176   LayoutKind kind() const {
 177     assert(_kind != LayoutKind::UNKNOWN, "Not set");
 178     return _kind;
 179   }
 180   void set_kind(LayoutKind lk) { _kind = lk; }
 181 
 182   int null_marker_offset() const {
 183     assert(_null_marker_offset != -1, "Not set");
 184     return _null_marker_offset;
 185   }
 186   void set_null_marker_offset(int o) { _null_marker_offset = o; }
 187 
 188   void metaspace_pointers_do(MetaspaceClosure* it);
 189   MetaspaceObj::Type type() const { return InlineLayoutInfoType; }
 190 
 191   static ByteSize klass_offset() { return in_ByteSize(offset_of(InlineLayoutInfo, _klass)); }
 192   static ByteSize null_marker_offset_offset() { return in_ByteSize(offset_of(InlineLayoutInfo, _null_marker_offset)); }
 193 };
 194 
 195 class InstanceKlass: public Klass {
 196   friend class VMStructs;
 197   friend class JVMCIVMStructs;
 198   friend class ClassFileParser;
 199   friend class CompileReplay;
 200   friend class TemplateTable;
 201 
 202  public:
 203   static const KlassKind Kind = InstanceKlassKind;
 204 
 205  protected:
 206   InstanceKlass(const ClassFileParser& parser, KlassKind kind = Kind, markWord prototype = markWord::prototype(), ReferenceType reference_type = REF_NONE);
 207 
 208  public:
 209   InstanceKlass();
 210 
 211   // See "The Java Virtual Machine Specification" section 2.16.2-5 for a detailed description
 212   // of the class loading & initialization procedure, and the use of the states.
 213   enum ClassState : u1 {
 214     allocated,                          // allocated (but not yet linked)
 215     loaded,                             // loaded and inserted in class hierarchy (but not linked yet)
 216     linked,                             // successfully linked/verified (but not initialized yet)
 217     being_initialized,                  // currently running class initializer
 218     fully_initialized,                  // initialized (successful final state)
 219     initialization_error                // error happened during initialization
 220   };
 221 
 222  private:
 223   static InstanceKlass* allocate_instance_klass(const ClassFileParser& parser, TRAPS);
 224 
 225  protected:
 226   // If you add a new field that points to any metaspace object, you
 227   // must add this field to InstanceKlass::metaspace_pointers_do().
 228 
 229   // Annotations for this class
 230   Annotations*    _annotations;
 231   // Package this class is defined in
 232   PackageEntry*   _package_entry;
 233   // Array classes holding elements of this class.
 234   ObjArrayKlass* volatile _array_klasses;
 235   // Constant pool for this class.
 236   ConstantPool* _constants;
 237   // The InnerClasses attribute and EnclosingMethod attribute. The
 238   // _inner_classes is an array of shorts. If the class has InnerClasses
 239   // attribute, then the _inner_classes array begins with 4-tuples of shorts
 240   // [inner_class_info_index, outer_class_info_index,
 241   // inner_name_index, inner_class_access_flags] for the InnerClasses
 242   // attribute. If the EnclosingMethod attribute exists, it occupies the
 243   // last two shorts [class_index, method_index] of the array. If only
 244   // the InnerClasses attribute exists, the _inner_classes array length is
 245   // number_of_inner_classes * 4. If the class has both InnerClasses
 246   // and EnclosingMethod attributes the _inner_classes array length is
 247   // number_of_inner_classes * 4 + enclosing_method_attribute_size.
 248   Array<jushort>* _inner_classes;
 249 
 250   // The NestMembers attribute. An array of shorts, where each is a
 251   // class info index for the class that is a nest member. This data
 252   // has not been validated.
 253   Array<jushort>* _nest_members;
 254 
 255   // Resolved nest-host klass: either true nest-host or self if we are not
 256   // nested, or an error occurred resolving or validating the nominated
 257   // nest-host. Can also be set directly by JDK API's that establish nest
 258   // relationships.
 259   // By always being set it makes nest-member access checks simpler.
 260   InstanceKlass* _nest_host;
 261 
 262   // The PermittedSubclasses attribute. An array of shorts, where each is a
 263   // class info index for the class that is a permitted subclass.
 264   Array<jushort>* _permitted_subclasses;
 265 
 266   // The contents of the Record attribute.
 267   Array<RecordComponent*>* _record_components;
 268 
 269   // the source debug extension for this klass, null if not specified.
 270   // Specified as UTF-8 string without terminating zero byte in the classfile,
 271   // it is stored in the instanceklass as a null-terminated UTF-8 string
 272   const char*     _source_debug_extension;
 273 
 274   // Number of heapOopSize words used by non-static fields in this klass
 275   // (including inherited fields but after header_size()).
 276   int             _nonstatic_field_size;
 277   int             _static_field_size;       // number words used by static fields (oop and non-oop) in this klass
 278   int             _nonstatic_oop_map_size;  // size in words of nonstatic oop map blocks
 279   int             _itable_len;              // length of Java itable (in words)
 280 
 281   // The NestHost attribute. The class info index for the class
 282   // that is the nest-host of this class. This data has not been validated.
 283   u2              _nest_host_index;
 284   u2              _this_class_index;        // constant pool entry
 285   u2              _static_oop_field_count;  // number of static oop fields in this klass
 286 
 287   volatile u2     _idnum_allocated_count;   // JNI/JVMTI: increments with the addition of methods, old ids don't change
 288 
 289   // Class states are defined as ClassState (see above).
 290   // Place the _init_state here to utilize the unused 2-byte after
 291   // _idnum_allocated_count.
 292   volatile ClassState _init_state;          // state of class
 293 
 294   u1              _reference_type;                // reference type
 295 
 296   // State is set either at parse time or while executing, atomically to not disturb other state
 297   InstanceKlassFlags _misc_flags;
 298 
 299   JavaThread* volatile _init_thread;        // Pointer to current thread doing initialization (to handle recursive initialization)
 300 
 301   OopMapCache*    volatile _oop_map_cache;   // OopMapCache for all methods in the klass (allocated lazily)
 302   JNIid*          _jni_ids;                  // First JNI identifier for static fields in this class
 303   jmethodID* volatile _methods_jmethod_ids;  // jmethodIDs corresponding to method_idnum, or null if none
 304   nmethodBucket*  volatile _dep_context;     // packed DependencyContext structure
 305   uint64_t        volatile _dep_context_last_cleaned;
 306   nmethod*        _osr_nmethods_head;    // Head of list of on-stack replacement nmethods for this class
 307 #if INCLUDE_JVMTI
 308   BreakpointInfo* _breakpoints;          // bpt lists, managed by Method*
 309   // Linked instanceKlasses of previous versions
 310   InstanceKlass* _previous_versions;
 311   // JVMTI fields can be moved to their own structure - see 6315920
 312   // JVMTI: cached class file, before retransformable agent modified it in CFLH
 313   JvmtiCachedClassFileData* _cached_class_file;
 314 #endif
 315 
 316 #if INCLUDE_JVMTI
 317   JvmtiCachedClassFieldMap* _jvmti_cached_class_field_map;  // JVMTI: used during heap iteration
 318 #endif
 319 
 320   NOT_PRODUCT(int _verify_count;)  // to avoid redundant verifies
 321   NOT_PRODUCT(volatile int _shared_class_load_count;) // ensure a shared class is loaded only once
 322 
 323   // Method array.
 324   Array<Method*>* _methods;
 325   // Default Method Array, concrete methods inherited from interfaces
 326   Array<Method*>* _default_methods;
 327   // Interfaces (InstanceKlass*s) this class declares locally to implement.
 328   Array<InstanceKlass*>* _local_interfaces;
 329   // Interfaces (InstanceKlass*s) this class implements transitively.
 330   Array<InstanceKlass*>* _transitive_interfaces;
 331   // Int array containing the original order of method in the class file (for JVMTI).
 332   Array<int>*     _method_ordering;
 333   // Int array containing the vtable_indices for default_methods
 334   // offset matches _default_methods offset
 335   Array<int>*     _default_vtable_indices;
 336 
 337   // Fields information is stored in an UNSIGNED5 encoded stream (see fieldInfo.hpp)
 338   Array<u1>*          _fieldinfo_stream;
 339   Array<u1>*          _fieldinfo_search_table;
 340   Array<FieldStatus>* _fields_status;
 341 
 342   Array<InlineLayoutInfo>* _inline_layout_info_array;
 343   Array<u2>* _loadable_descriptors;
 344   const InlineKlassFixedBlock* _adr_inlineklass_fixed_block;
 345 
 346   // embedded Java vtable follows here
 347   // embedded Java itables follows here
 348   // embedded static fields follows here
 349   // embedded nonstatic oop-map blocks follows here
 350   // embedded implementor of this interface follows here
 351   //   The embedded implementor only exists if the current klass is an
 352   //   interface. The possible values of the implementor fall into following
 353   //   three cases:
 354   //     null: no implementor.
 355   //     A Klass* that's not itself: one implementor.
 356   //     Itself: more than one implementors.
 357   //
 358 
 359   friend class SystemDictionary;
 360 
 361   static bool _disable_method_binary_search;
 362 
 363   // Controls finalizer registration
 364   static bool _finalization_enabled;
 365 
 366  public:
 367 
 368   // Queries finalization state
 369   static bool is_finalization_enabled() { return _finalization_enabled; }
 370 
 371   // Sets finalization state
 372   static void set_finalization_enabled(bool val) { _finalization_enabled = val; }
 373 
 374   // Quick checks for the loader that defined this class (without switching on this->class_loader())
 375   bool defined_by_boot_loader() const      { return _misc_flags.defined_by_boot_loader(); }
 376   bool defined_by_platform_loader() const  { return _misc_flags.defined_by_platform_loader(); }
 377   bool defined_by_app_loader() const       { return _misc_flags.defined_by_app_loader(); }
 378   bool defined_by_other_loaders() const    { return _misc_flags.defined_by_other_loaders(); }
 379   void set_class_loader_type()             { _misc_flags.set_class_loader_type(_class_loader_data); }
 380 
 381   // Check if the class can be shared in CDS
 382   bool is_shareable() const;
 383 
 384   bool shared_loading_failed() const { return _misc_flags.shared_loading_failed(); }
 385 
 386   void set_shared_loading_failed() { _misc_flags.set_shared_loading_failed(true); }
 387 
 388   bool has_nonstatic_fields() const        { return _misc_flags.has_nonstatic_fields(); }
 389   void set_has_nonstatic_fields(bool b)    { _misc_flags.set_has_nonstatic_fields(b); }
 390 
 391   bool has_localvariable_table() const     { return _misc_flags.has_localvariable_table(); }
 392   void set_has_localvariable_table(bool b) { _misc_flags.set_has_localvariable_table(b); }
 393 
 394   bool has_inline_type_fields() const { return _misc_flags.has_inline_type_fields(); }
 395   void set_has_inline_type_fields()   { _misc_flags.set_has_inline_type_fields(true); }
 396 
 397   bool is_naturally_atomic() const  { return _misc_flags.is_naturally_atomic(); }
 398   void set_is_naturally_atomic()    { _misc_flags.set_is_naturally_atomic(true); }
 399 
 400   // Query if this class has atomicity requirements (default is yes)
 401   // This bit can occur anywhere, but is only significant
 402   // for inline classes *and* their super types.
 403   // It inherits from supers.
 404   // Its value depends on the ForceNonTearable VM option, the LooselyConsistentValue annotation
 405   // and the presence of flat fields with atomicity requirements
 406   bool must_be_atomic() const { return _misc_flags.must_be_atomic(); }
 407   void set_must_be_atomic()   { _misc_flags.set_must_be_atomic(true); }
 408 
 409   // field sizes
 410   int nonstatic_field_size() const         { return _nonstatic_field_size; }
 411   void set_nonstatic_field_size(int size)  { _nonstatic_field_size = size; }
 412 
 413   int static_field_size() const            { return _static_field_size; }
 414   void set_static_field_size(int size)     { _static_field_size = size; }
 415 
 416   int static_oop_field_count() const       { return (int)_static_oop_field_count; }
 417   void set_static_oop_field_count(u2 size) { _static_oop_field_count = size; }
 418 
 419   // Java itable
 420   int  itable_length() const               { return _itable_len; }
 421   void set_itable_length(int len)          { _itable_len = len; }
 422 
 423   // array klasses
 424   ObjArrayKlass* array_klasses() const     { return _array_klasses; }
 425   inline ObjArrayKlass* array_klasses_acquire() const; // load with acquire semantics
 426   inline void release_set_array_klasses(ObjArrayKlass* k); // store with release semantics
 427   void set_array_klasses(ObjArrayKlass* k) { _array_klasses = k; }
 428 
 429   // methods
 430   Array<Method*>* methods() const          { return _methods; }
 431   void set_methods(Array<Method*>* a)      { _methods = a; }
 432   Method* method_with_idnum(int idnum) const;
 433   Method* method_with_orig_idnum(int idnum) const;
 434   Method* method_with_orig_idnum(int idnum, int version) const;
 435 
 436   // method ordering
 437   Array<int>* method_ordering() const     { return _method_ordering; }
 438   void set_method_ordering(Array<int>* m) { _method_ordering = m; }
 439   void copy_method_ordering(const intArray* m, TRAPS);
 440 
 441   // default_methods
 442   Array<Method*>* default_methods() const  { return _default_methods; }
 443   void set_default_methods(Array<Method*>* a) { _default_methods = a; }
 444 
 445   // default method vtable_indices
 446   Array<int>* default_vtable_indices() const { return _default_vtable_indices; }
 447   void set_default_vtable_indices(Array<int>* v) { _default_vtable_indices = v; }
 448   Array<int>* create_new_default_vtable_indices(int len, TRAPS);
 449 
 450   // interfaces
 451   Array<InstanceKlass*>* local_interfaces() const          { return _local_interfaces; }
 452   void set_local_interfaces(Array<InstanceKlass*>* a)      {
 453     guarantee(_local_interfaces == nullptr || a == nullptr, "Just checking");
 454     _local_interfaces = a; }
 455 
 456   Array<InstanceKlass*>* transitive_interfaces() const     { return _transitive_interfaces; }
 457   void set_transitive_interfaces(Array<InstanceKlass*>* a) {
 458     guarantee(_transitive_interfaces == nullptr || a == nullptr, "Just checking");
 459     _transitive_interfaces = a;
 460   }
 461 
 462  private:
 463   friend class fieldDescriptor;
 464   FieldInfo field(int index) const;
 465 
 466  public:
 467   int     field_offset      (int index) const { return field(index).offset(); }
 468   int     field_access_flags(int index) const { return field(index).access_flags().as_field_flags(); }
 469   FieldInfo::FieldFlags field_flags(int index) const { return field(index).field_flags(); }
 470   FieldStatus field_status(int index)   const { return fields_status()->at(index); }
 471   inline Symbol* field_name        (int index) const;
 472   inline Symbol* field_signature   (int index) const;
 473   bool field_is_flat(int index) const { return field_flags(index).is_flat(); }
 474   bool field_has_null_marker(int index) const { return field_flags(index).has_null_marker(); }
 475   bool field_is_null_free_inline_type(int index) const;
 476   bool is_class_in_loadable_descriptors_attribute(Symbol* name) const;
 477 
 478   int null_marker_offset(int index) const { return inline_layout_info(index).null_marker_offset(); }
 479 
 480   // Number of Java declared fields
 481   int java_fields_count() const;
 482   int total_fields_count() const;
 483 
 484   Array<u1>* fieldinfo_stream() const { return _fieldinfo_stream; }
 485   void set_fieldinfo_stream(Array<u1>* fis) { _fieldinfo_stream = fis; }
 486 
 487   Array<u1>* fieldinfo_search_table() const { return _fieldinfo_search_table; }
 488   void set_fieldinfo_search_table(Array<u1>* table) { _fieldinfo_search_table = table; }
 489 
 490   Array<FieldStatus>* fields_status() const {return _fields_status; }
 491   void set_fields_status(Array<FieldStatus>* array) { _fields_status = array; }
 492 
 493   Array<u2>* loadable_descriptors() const { return _loadable_descriptors; }
 494   void set_loadable_descriptors(Array<u2>* c) { _loadable_descriptors = c; }
 495 
 496   // inner classes
 497   Array<u2>* inner_classes() const       { return _inner_classes; }
 498   void set_inner_classes(Array<u2>* f)   { _inner_classes = f; }
 499 
 500   // nest members
 501   Array<u2>* nest_members() const     { return _nest_members; }
 502   void set_nest_members(Array<u2>* m) { _nest_members = m; }
 503 
 504   // nest-host index
 505   jushort nest_host_index() const { return _nest_host_index; }
 506   void set_nest_host_index(u2 i)  { _nest_host_index = i; }
 507   // dynamic nest member support
 508   void set_nest_host(InstanceKlass* host);
 509 
 510   // record components
 511   Array<RecordComponent*>* record_components() const { return _record_components; }
 512   void set_record_components(Array<RecordComponent*>* record_components) {
 513     _record_components = record_components;
 514   }
 515   bool is_record() const;
 516 
 517   // test for enum class (or possibly an anonymous subclass within a sealed enum)
 518   bool is_enum_subclass() const;
 519 
 520   // permitted subclasses
 521   Array<u2>* permitted_subclasses() const     { return _permitted_subclasses; }
 522   void set_permitted_subclasses(Array<u2>* s) { _permitted_subclasses = s; }
 523 
 524 private:
 525   // Called to verify that k is a member of this nest - does not look at k's nest-host,
 526   // nor does it resolve any CP entries or load any classes.
 527   bool has_nest_member(JavaThread* current, InstanceKlass* k) const;
 528 
 529 public:
 530   // Call this only if you know that the nest host has been initialized.
 531   InstanceKlass* nest_host_not_null() {
 532     assert(_nest_host != nullptr, "must be");
 533     return _nest_host;
 534   }
 535   InstanceKlass* nest_host_or_null() {
 536     return _nest_host;
 537   }
 538   // Used to construct informative IllegalAccessError messages at a higher level,
 539   // if there was an issue resolving or validating the nest host.
 540   // Returns null if there was no error.
 541   const char* nest_host_error();
 542   // Returns nest-host class, resolving and validating it if needed.
 543   // Returns null if resolution is not possible from the calling context.
 544   InstanceKlass* nest_host(TRAPS);
 545   // Check if this klass is a nestmate of k - resolves this nest-host and k's
 546   bool has_nestmate_access_to(InstanceKlass* k, TRAPS);
 547 
 548   // Called to verify that k is a permitted subclass of this class.
 549   // The incoming stringStream is used for logging, and for the caller to create
 550   // a detailed exception message on failure.
 551   bool has_as_permitted_subclass(const InstanceKlass* k, stringStream& ss) const;
 552 
 553   enum InnerClassAttributeOffset {
 554     // From http://mirror.eng/products/jdk/1.1/docs/guide/innerclasses/spec/innerclasses.doc10.html#18814
 555     inner_class_inner_class_info_offset = 0,
 556     inner_class_outer_class_info_offset = 1,
 557     inner_class_inner_name_offset = 2,
 558     inner_class_access_flags_offset = 3,
 559     inner_class_next_offset = 4
 560   };
 561 
 562   enum EnclosingMethodAttributeOffset {
 563     enclosing_method_class_index_offset = 0,
 564     enclosing_method_method_index_offset = 1,
 565     enclosing_method_attribute_size = 2
 566   };
 567 
 568   // package
 569   PackageEntry* package() const     { return _package_entry; }
 570   ModuleEntry* module() const;
 571   bool in_javabase_module() const;
 572   bool in_unnamed_package() const   { return (_package_entry == nullptr); }
 573   void set_package(ClassLoaderData* loader_data, PackageEntry* pkg_entry, TRAPS);
 574   // If the package for the InstanceKlass is in the boot loader's package entry
 575   // table then sets the classpath_index field so that
 576   // get_system_package() will know to return a non-null value for the
 577   // package's location.  And, so that the package will be added to the list of
 578   // packages returned by get_system_packages().
 579   // For packages whose classes are loaded from the boot loader class path, the
 580   // classpath_index indicates which entry on the boot loader class path.
 581   void set_classpath_index(s2 path_index);
 582   bool is_same_class_package(const Klass* class2) const;
 583   bool is_same_class_package(oop other_class_loader, const Symbol* other_class_name) const;
 584 
 585   // find an enclosing class
 586   InstanceKlass* compute_enclosing_class(bool* inner_is_member, TRAPS) const;
 587 
 588   // Find InnerClasses attribute and return outer_class_info_index & inner_name_index.
 589   bool find_inner_classes_attr(int* ooff, int* noff, TRAPS) const;
 590 
 591   // Check if this klass can be null-free
 592   static void check_can_be_annotated_with_NullRestricted(InstanceKlass* type, Symbol* container_klass_name, TRAPS);
 593 
 594  private:
 595   // Check prohibited package ("java/" only loadable by boot or platform loaders)
 596   static void check_prohibited_package(Symbol* class_name,
 597                                        ClassLoaderData* loader_data,
 598                                        TRAPS);
 599 
 600   JavaThread* init_thread()  { return AtomicAccess::load(&_init_thread); }
 601   const char* init_thread_name() {
 602     return init_thread()->name_raw();
 603   }
 604 
 605  public:
 606   // initialization state
 607   bool is_loaded() const                   { return init_state() >= loaded; }
 608   bool is_linked() const                   { return init_state() >= linked; }
 609   bool is_initialized() const              { return init_state() == fully_initialized; }
 610   bool is_not_initialized() const          { return init_state() <  being_initialized; }
 611   bool is_being_initialized() const        { return init_state() == being_initialized; }
 612   bool is_in_error_state() const           { return init_state() == initialization_error; }
 613   bool is_reentrant_initialization(Thread *thread)  { return thread == _init_thread; }
 614   ClassState  init_state() const           { return AtomicAccess::load_acquire(&_init_state); }
 615   const char* init_state_name() const;
 616   bool is_rewritten() const                { return _misc_flags.rewritten(); }
 617 
 618   // is this a sealed class
 619   bool is_sealed() const;
 620 
 621   // defineClass specified verification
 622   bool should_verify_class() const         { return _misc_flags.should_verify_class(); }
 623   void set_should_verify_class(bool value) { _misc_flags.set_should_verify_class(value); }
 624 
 625   // marking
 626   bool is_marked_dependent() const         { return _misc_flags.is_marked_dependent(); }
 627   void set_is_marked_dependent(bool value) { _misc_flags.set_is_marked_dependent(value); }
 628 
 629   static ByteSize kind_offset() { return in_ByteSize(offset_of(InstanceKlass, _kind)); }
 630   static ByteSize misc_flags_offset() { return in_ByteSize(offset_of(InstanceKlass, _misc_flags)); }
 631 
 632   // initialization (virtuals from Klass)
 633   bool should_be_initialized() const;  // means that initialize should be called
 634   void initialize_with_aot_initialized_mirror(TRAPS);
 635   void assert_no_clinit_will_run_for_aot_initialized_class() const NOT_DEBUG_RETURN;
 636   void initialize(TRAPS);
 637   void link_class(TRAPS);
 638   bool link_class_or_fail(TRAPS); // returns false on failure
 639   void rewrite_class(TRAPS);
 640   void link_methods(TRAPS);
 641   Method* class_initializer() const;
 642   bool interface_needs_clinit_execution_as_super(bool also_check_supers=true) const;
 643 
 644   // reference type
 645   ReferenceType reference_type() const     { return (ReferenceType)_reference_type; }
 646 
 647   // this class cp index
 648   u2 this_class_index() const             { return _this_class_index; }
 649   void set_this_class_index(u2 index)     { _this_class_index = index; }
 650 
 651   static ByteSize reference_type_offset() { return byte_offset_of(InstanceKlass, _reference_type); }
 652 
 653   // find local field, returns true if found
 654   bool find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
 655   // find field in direct superinterfaces, returns the interface in which the field is defined
 656   Klass* find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
 657   // find field according to JVM spec 5.4.3.2, returns the klass in which the field is defined
 658   Klass* find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const;
 659   // find instance or static fields according to JVM spec 5.4.3.2, returns the klass in which the field is defined
 660   Klass* find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const;
 661 
 662   // find a non-static or static field given its offset within the class.
 663   bool contains_field_offset(int offset);
 664 
 665   bool find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const;
 666   bool find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const;
 667 
 668  private:
 669   inline static int quick_search(const Array<Method*>* methods, const Symbol* name);
 670 
 671  public:
 672   static void disable_method_binary_search() {
 673     _disable_method_binary_search = true;
 674   }
 675 
 676   // find a local method (returns null if not found)
 677   Method* find_method(const Symbol* name, const Symbol* signature) const;
 678   static Method* find_method(const Array<Method*>* methods,
 679                              const Symbol* name,
 680                              const Symbol* signature);
 681 
 682   // find a local method, but skip static methods
 683   Method* find_instance_method(const Symbol* name, const Symbol* signature,
 684                                PrivateLookupMode private_mode) const;
 685   static Method* find_instance_method(const Array<Method*>* methods,
 686                                       const Symbol* name,
 687                                       const Symbol* signature,
 688                                       PrivateLookupMode private_mode);
 689 
 690   // find a local method (returns null if not found)
 691   Method* find_local_method(const Symbol* name,
 692                             const Symbol* signature,
 693                             OverpassLookupMode overpass_mode,
 694                             StaticLookupMode static_mode,
 695                             PrivateLookupMode private_mode) const;
 696 
 697   // find a local method from given methods array (returns null if not found)
 698   static Method* find_local_method(const Array<Method*>* methods,
 699                                    const Symbol* name,
 700                                    const Symbol* signature,
 701                                    OverpassLookupMode overpass_mode,
 702                                    StaticLookupMode static_mode,
 703                                    PrivateLookupMode private_mode);
 704 
 705   // find a local method index in methods or default_methods (returns -1 if not found)
 706   static int find_method_index(const Array<Method*>* methods,
 707                                const Symbol* name,
 708                                const Symbol* signature,
 709                                OverpassLookupMode overpass_mode,
 710                                StaticLookupMode static_mode,
 711                                PrivateLookupMode private_mode);
 712 
 713   // lookup operation (returns null if not found)
 714   Method* uncached_lookup_method(const Symbol* name,
 715                                  const Symbol* signature,
 716                                  OverpassLookupMode overpass_mode,
 717                                  PrivateLookupMode private_mode = PrivateLookupMode::find) const;
 718 
 719   // lookup a method in all the interfaces that this class implements
 720   // (returns null if not found)
 721   Method* lookup_method_in_all_interfaces(Symbol* name, Symbol* signature, DefaultsLookupMode defaults_mode) const;
 722 
 723   // lookup a method in local defaults then in all interfaces
 724   // (returns null if not found)
 725   Method* lookup_method_in_ordered_interfaces(Symbol* name, Symbol* signature) const;
 726 
 727   // Find method indices by name.  If a method with the specified name is
 728   // found the index to the first method is returned, and 'end' is filled in
 729   // with the index of first non-name-matching method.  If no method is found
 730   // -1 is returned.
 731   int find_method_by_name(const Symbol* name, int* end) const;
 732   static int find_method_by_name(const Array<Method*>* methods,
 733                                  const Symbol* name, int* end);
 734 
 735   // constant pool
 736   ConstantPool* constants() const        { return _constants; }
 737   void set_constants(ConstantPool* c)    { _constants = c; }
 738 
 739   // protection domain
 740   oop protection_domain() const;
 741 
 742   // signers
 743   objArrayOop signers() const;
 744 
 745   bool is_contended() const                { return _misc_flags.is_contended(); }
 746   void set_is_contended(bool value)        { _misc_flags.set_is_contended(value); }
 747 
 748   // source file name
 749   Symbol* source_file_name() const;
 750   u2 source_file_name_index() const;
 751   void set_source_file_name_index(u2 sourcefile_index);
 752 
 753   // minor and major version numbers of class file
 754   u2 minor_version() const;
 755   void set_minor_version(u2 minor_version);
 756   u2 major_version() const;
 757   void set_major_version(u2 major_version);
 758 
 759   bool supports_inline_types() const;
 760 
 761   // source debug extension
 762   const char* source_debug_extension() const { return _source_debug_extension; }
 763   void set_source_debug_extension(const char* array, int length);
 764 
 765   // nonstatic oop-map blocks
 766   static int nonstatic_oop_map_size(unsigned int oop_map_count) {
 767     return oop_map_count * OopMapBlock::size_in_words();
 768   }
 769   unsigned int nonstatic_oop_map_count() const {
 770     return _nonstatic_oop_map_size / OopMapBlock::size_in_words();
 771   }
 772   int nonstatic_oop_map_size() const { return _nonstatic_oop_map_size; }
 773   void set_nonstatic_oop_map_size(int words) {
 774     _nonstatic_oop_map_size = words;
 775   }
 776 
 777   bool has_contended_annotations() const { return _misc_flags.has_contended_annotations(); }
 778   void set_has_contended_annotations(bool value)  { _misc_flags.set_has_contended_annotations(value); }
 779 
 780 #if INCLUDE_JVMTI
 781   // Redefinition locking.  Class can only be redefined by one thread at a time.
 782   bool is_being_redefined() const          { return _misc_flags.is_being_redefined(); }
 783   void set_is_being_redefined(bool value)  { _misc_flags.set_is_being_redefined(value); }
 784 
 785   // RedefineClasses() support for previous versions:
 786   void add_previous_version(InstanceKlass* ik, int emcp_method_count);
 787   void purge_previous_version_list();
 788 
 789   InstanceKlass* previous_versions() const { return _previous_versions; }
 790 #else
 791   InstanceKlass* previous_versions() const { return nullptr; }
 792 #endif
 793 
 794   const InstanceKlass* get_klass_version(int version) const;
 795 
 796   bool has_been_redefined() const { return _misc_flags.has_been_redefined(); }
 797   void set_has_been_redefined() { _misc_flags.set_has_been_redefined(true); }
 798 
 799   bool is_scratch_class() const { return _misc_flags.is_scratch_class(); }
 800   void set_is_scratch_class() { _misc_flags.set_is_scratch_class(true); }
 801 
 802   bool has_resolved_methods() const { return _misc_flags.has_resolved_methods(); }
 803   void set_has_resolved_methods()   { _misc_flags.set_has_resolved_methods(true); }
 804   void set_has_resolved_methods(bool value)   { _misc_flags.set_has_resolved_methods(value); }
 805 
 806 public:
 807 #if INCLUDE_JVMTI
 808 
 809   void init_previous_versions() {
 810     _previous_versions = nullptr;
 811   }
 812 
 813  private:
 814   static bool  _should_clean_previous_versions;
 815  public:
 816   static void purge_previous_versions(InstanceKlass* ik) {
 817     if (ik->has_been_redefined()) {
 818       ik->purge_previous_version_list();
 819     }
 820   }
 821 
 822   static bool should_clean_previous_versions_and_reset();
 823   static bool should_clean_previous_versions() { return _should_clean_previous_versions; }
 824 
 825   // JVMTI: Support for caching a class file before it is modified by an agent that can do retransformation
 826   void set_cached_class_file(JvmtiCachedClassFileData *data) {
 827     _cached_class_file = data;
 828   }
 829   JvmtiCachedClassFileData * get_cached_class_file();
 830   jint get_cached_class_file_len();
 831   unsigned char * get_cached_class_file_bytes();
 832 
 833   // JVMTI: Support for caching of field indices, types, and offsets
 834   void set_jvmti_cached_class_field_map(JvmtiCachedClassFieldMap* descriptor) {
 835     _jvmti_cached_class_field_map = descriptor;
 836   }
 837   JvmtiCachedClassFieldMap* jvmti_cached_class_field_map() const {
 838     return _jvmti_cached_class_field_map;
 839   }
 840 #else // INCLUDE_JVMTI
 841 
 842   static void purge_previous_versions(InstanceKlass* ik) { return; };
 843   static bool should_clean_previous_versions_and_reset() { return false; }
 844 
 845   void set_cached_class_file(JvmtiCachedClassFileData *data) {
 846     assert(data == nullptr, "unexpected call with JVMTI disabled");
 847   }
 848   JvmtiCachedClassFileData * get_cached_class_file() { return (JvmtiCachedClassFileData *)nullptr; }
 849 
 850 #endif // INCLUDE_JVMTI
 851 
 852   bool has_nonstatic_concrete_methods() const { return _misc_flags.has_nonstatic_concrete_methods(); }
 853   void set_has_nonstatic_concrete_methods(bool b) { _misc_flags.set_has_nonstatic_concrete_methods(b); }
 854 
 855   bool declares_nonstatic_concrete_methods() const { return _misc_flags.declares_nonstatic_concrete_methods(); }
 856   void set_declares_nonstatic_concrete_methods(bool b) { _misc_flags.set_declares_nonstatic_concrete_methods(b); }
 857 
 858   bool has_miranda_methods () const     { return _misc_flags.has_miranda_methods(); }
 859   void set_has_miranda_methods()        { _misc_flags.set_has_miranda_methods(true); }
 860   bool has_final_method() const         { return _misc_flags.has_final_method(); }
 861   void set_has_final_method()           { _misc_flags.set_has_final_method(true); }
 862 
 863   // for adding methods, ConstMethod::UNSET_IDNUM means no more ids available
 864   inline u2 next_method_idnum();
 865   void set_initial_method_idnum(u2 value)             { _idnum_allocated_count = value; }
 866 
 867   // runtime support for strict statics
 868   bool has_strict_static_fields() const     { return _misc_flags.has_strict_static_fields(); }
 869   void set_has_strict_static_fields(bool b) { _misc_flags.set_has_strict_static_fields(b); }
 870   void notify_strict_static_access(int field_index, bool is_writing, TRAPS);
 871   const char* format_strict_static_message(Symbol* field_name, const char* doing_what = nullptr);
 872   void throw_strict_static_exception(Symbol* field_name, const char* when, TRAPS);
 873 
 874   // generics support
 875   Symbol* generic_signature() const;
 876   u2 generic_signature_index() const;
 877   void set_generic_signature_index(u2 sig_index);
 878 
 879   u2 enclosing_method_data(int offset) const;
 880   u2 enclosing_method_class_index() const {
 881     return enclosing_method_data(enclosing_method_class_index_offset);
 882   }
 883   u2 enclosing_method_method_index() {
 884     return enclosing_method_data(enclosing_method_method_index_offset);
 885   }
 886   void set_enclosing_method_indices(u2 class_index,
 887                                     u2 method_index);
 888 
 889   // jmethodID support
 890   jmethodID get_jmethod_id(Method* method);
 891   void make_methods_jmethod_ids();
 892   jmethodID jmethod_id_or_null(Method* method);
 893   void update_methods_jmethod_cache();
 894 
 895   // annotations support
 896   Annotations* annotations() const          { return _annotations; }
 897   void set_annotations(Annotations* anno)   { _annotations = anno; }
 898 
 899   AnnotationArray* class_annotations() const {
 900     return (_annotations != nullptr) ? _annotations->class_annotations() : nullptr;
 901   }
 902   Array<AnnotationArray*>* fields_annotations() const {
 903     return (_annotations != nullptr) ? _annotations->fields_annotations() : nullptr;
 904   }
 905   AnnotationArray* class_type_annotations() const {
 906     return (_annotations != nullptr) ? _annotations->class_type_annotations() : nullptr;
 907   }
 908   Array<AnnotationArray*>* fields_type_annotations() const {
 909     return (_annotations != nullptr) ? _annotations->fields_type_annotations() : nullptr;
 910   }
 911   // allocation
 912   instanceOop allocate_instance(TRAPS);
 913   static instanceOop allocate_instance(oop cls, TRAPS);
 914 
 915   // additional member function to return a handle
 916   instanceHandle allocate_instance_handle(TRAPS);
 917 
 918   // Helper function
 919   static instanceOop register_finalizer(instanceOop i, TRAPS);
 920 
 921   // Check whether reflection/jni/jvm code is allowed to instantiate this class;
 922   // if not, throw either an Error or an Exception.
 923   virtual void check_valid_for_instantiation(bool throwError, TRAPS);
 924 
 925   // initialization
 926   void call_class_initializer(TRAPS);
 927   void set_initialization_state_and_notify(ClassState state, TRAPS);
 928 
 929   // OopMapCache support
 930   OopMapCache* oop_map_cache()               { return _oop_map_cache; }
 931   void set_oop_map_cache(OopMapCache *cache) { _oop_map_cache = cache; }
 932   void mask_for(const methodHandle& method, int bci, InterpreterOopMap* entry);
 933 
 934   // JNI identifier support (for static fields - for jni performance)
 935   JNIid* jni_ids()                               { return _jni_ids; }
 936   void set_jni_ids(JNIid* ids)                   { _jni_ids = ids; }
 937   JNIid* jni_id_for(int offset);
 938 
 939  public:
 940   // maintenance of deoptimization dependencies
 941   inline DependencyContext dependencies();
 942   void mark_dependent_nmethods(DeoptimizationScope* deopt_scope, KlassDepChange& changes);
 943   void add_dependent_nmethod(nmethod* nm);
 944   void clean_dependency_context();
 945   // Setup link to hierarchy and deoptimize
 946   void add_to_hierarchy(JavaThread* current);
 947 
 948   // On-stack replacement support
 949   nmethod* osr_nmethods_head() const         { return _osr_nmethods_head; };
 950   void set_osr_nmethods_head(nmethod* h)     { _osr_nmethods_head = h; };
 951   void add_osr_nmethod(nmethod* n);
 952   bool remove_osr_nmethod(nmethod* n);
 953   int mark_osr_nmethods(DeoptimizationScope* deopt_scope, const Method* m);
 954   nmethod* lookup_osr_nmethod(const Method* m, int bci, int level, bool match_level) const;
 955 
 956 #if INCLUDE_JVMTI
 957   // Breakpoint support (see methods on Method* for details)
 958   BreakpointInfo* breakpoints() const       { return _breakpoints; };
 959   void set_breakpoints(BreakpointInfo* bps) { _breakpoints = bps; };
 960 #endif
 961 
 962   // support for stub routines
 963   static ByteSize init_state_offset()  { return byte_offset_of(InstanceKlass, _init_state); }
 964   JFR_ONLY(DEFINE_KLASS_TRACE_ID_OFFSET;)
 965   static ByteSize init_thread_offset() { return byte_offset_of(InstanceKlass, _init_thread); }
 966 
 967   static ByteSize inline_layout_info_array_offset() { return in_ByteSize(offset_of(InstanceKlass, _inline_layout_info_array)); }
 968   static ByteSize adr_inlineklass_fixed_block_offset() { return in_ByteSize(offset_of(InstanceKlass, _adr_inlineklass_fixed_block)); }
 969 
 970   // subclass/subinterface checks
 971   bool implements_interface(Klass* k) const;
 972   bool is_same_or_direct_interface(Klass* k) const;
 973 
 974 #ifdef ASSERT
 975   // check whether this class or one of its superclasses was redefined
 976   bool has_redefined_this_or_super() const;
 977 #endif
 978 
 979   // Access to the implementor of an interface.
 980   InstanceKlass* implementor() const;
 981   void set_implementor(InstanceKlass* ik);
 982   int  nof_implementors() const;
 983   void add_implementor(InstanceKlass* ik);  // ik is a new class that implements this interface
 984   void init_implementor();           // initialize
 985 
 986  private:
 987   // link this class into the implementors list of every interface it implements
 988   void process_interfaces();
 989 
 990  public:
 991   // virtual operations from Klass
 992   GrowableArray<Klass*>* compute_secondary_supers(int num_extra_slots,
 993                                                   Array<InstanceKlass*>* transitive_interfaces);
 994   bool can_be_primary_super_slow() const;
 995   size_t oop_size(oop obj)  const             { return size_helper(); }
 996   // slow because it's a virtual call and used for verifying the layout_helper.
 997   // Using the layout_helper bits, we can call is_instance_klass without a virtual call.
 998   DEBUG_ONLY(bool is_instance_klass_slow() const      { return true; })
 999 
1000   // Iterators
1001   void do_local_static_fields(FieldClosure* cl);
1002   void do_nonstatic_fields(FieldClosure* cl); // including inherited fields
1003   void do_local_static_fields(void f(fieldDescriptor*, Handle, TRAPS), Handle, TRAPS);
1004   void print_nonstatic_fields(FieldClosure* cl); // including inherited and injected fields
1005 
1006   void methods_do(void f(Method* method));
1007 
1008   static InstanceKlass* cast(Klass* k) {
1009     return const_cast<InstanceKlass*>(cast(const_cast<const Klass*>(k)));
1010   }
1011 
1012   static const InstanceKlass* cast(const Klass* k) {
1013     assert(k != nullptr, "k should not be null");
1014     assert(k->is_instance_klass(), "cast to InstanceKlass");
1015     return static_cast<const InstanceKlass*>(k);
1016   }
1017 
1018   // This hides Klass::super(). The _super of an InstanceKlass is
1019   // always an InstanceKlass (or nullptr)
1020   InstanceKlass* super() const {
1021     return (Klass::super() == nullptr) ? nullptr : InstanceKlass::cast(Klass::super());
1022   }
1023 
1024   virtual InstanceKlass* java_super() const {
1025     return InstanceKlass::super();
1026   }
1027 
1028   // Sizing (in words)
1029   static int header_size()            { return sizeof(InstanceKlass)/wordSize; }
1030 
1031   static int size(int vtable_length, int itable_length,
1032                   int nonstatic_oop_map_size,
1033                   bool is_interface,
1034                   bool is_inline_type) {
1035     return align_metadata_size(header_size() +
1036            vtable_length +
1037            itable_length +
1038            nonstatic_oop_map_size +
1039            (is_interface ? (int)sizeof(Klass*)/wordSize : 0) +
1040            (is_inline_type ? (int)sizeof(InlineKlassFixedBlock) : 0));
1041   }
1042 
1043   int size() const                    { return size(vtable_length(),
1044                                                itable_length(),
1045                                                nonstatic_oop_map_size(),
1046                                                is_interface(),
1047                                                is_inline_klass());
1048   }
1049 
1050 
1051   inline intptr_t* start_of_itable() const;
1052   inline intptr_t* end_of_itable() const;
1053   inline oop static_field_base_raw();
1054   bool bounds_check(address addr, bool edge_ok = false, intptr_t size_in_bytes = -1) const PRODUCT_RETURN0;
1055 
1056   inline OopMapBlock* start_of_nonstatic_oop_maps() const;
1057   inline Klass** end_of_nonstatic_oop_maps() const;
1058 
1059   inline InstanceKlass* volatile* adr_implementor() const;
1060 
1061   void set_inline_layout_info_array(Array<InlineLayoutInfo>* array) { _inline_layout_info_array = array; }
1062   Array<InlineLayoutInfo>* inline_layout_info_array() const { return _inline_layout_info_array; }
1063   void set_inline_layout_info(int index, InlineLayoutInfo *info) {
1064     assert(_inline_layout_info_array != nullptr ,"Array not created");
1065     _inline_layout_info_array->at_put(index, *info);
1066   }
1067   InlineLayoutInfo inline_layout_info(int index) const {
1068     assert(_inline_layout_info_array != nullptr ,"Array not created");
1069     return _inline_layout_info_array->at(index);
1070   }
1071   InlineLayoutInfo* inline_layout_info_adr(int index) {
1072     assert(_inline_layout_info_array != nullptr ,"Array not created");
1073     return _inline_layout_info_array->adr_at(index);
1074   }
1075 
1076   inline InlineKlass* get_inline_type_field_klass(int idx) const ;
1077   inline InlineKlass* get_inline_type_field_klass_or_null(int idx) const;
1078 
1079   // Use this to return the size of an instance in heap words:
1080   virtual int size_helper() const {
1081     return layout_helper_to_size_helper(layout_helper());
1082   }
1083 
1084   // This bit is initialized in classFileParser.cpp.
1085   // It is false under any of the following conditions:
1086   //  - the class is abstract (including any interface)
1087   //  - the class size is larger than FastAllocateSizeLimit
1088   //  - the class is java/lang/Class, which cannot be allocated directly
1089   bool can_be_fastpath_allocated() const {
1090     return !layout_helper_needs_slow_path(layout_helper());
1091   }
1092 
1093   // Java itable
1094   klassItable itable() const;        // return klassItable wrapper
1095   Method* method_at_itable(InstanceKlass* holder, int index, TRAPS);
1096   Method* method_at_itable_or_null(InstanceKlass* holder, int index, bool& itable_entry_found);
1097   int vtable_index_of_interface_method(Method* method);
1098 
1099 #if INCLUDE_JVMTI
1100   void adjust_default_methods(bool* trace_name_printed);
1101 #endif // INCLUDE_JVMTI
1102 
1103   void clean_weak_instanceklass_links();
1104  private:
1105   void clean_implementors_list();
1106   void clean_method_data();
1107 
1108  public:
1109   // Explicit metaspace deallocation of fields
1110   // For RedefineClasses and class file parsing errors, we need to deallocate
1111   // instanceKlasses and the metadata they point to.
1112   void deallocate_contents(ClassLoaderData* loader_data);
1113   static void deallocate_methods(ClassLoaderData* loader_data,
1114                                  Array<Method*>* methods);
1115   void static deallocate_interfaces(ClassLoaderData* loader_data,
1116                                     const InstanceKlass* super_klass,
1117                                     Array<InstanceKlass*>* local_interfaces,
1118                                     Array<InstanceKlass*>* transitive_interfaces);
1119   void static deallocate_record_components(ClassLoaderData* loader_data,
1120                                            Array<RecordComponent*>* record_component);
1121 
1122   virtual bool on_stack() const;
1123 
1124   // callbacks for actions during class unloading
1125   static void unload_class(InstanceKlass* ik);
1126 
1127   virtual void release_C_heap_structures(bool release_sub_metadata = true);
1128 
1129   // Naming
1130   const char* signature_name() const;
1131   const char* signature_name_of_carrier(char c) const;
1132 
1133   // Oop fields (and metadata) iterators
1134   //
1135   // The InstanceKlass iterators also visits the Object's klass.
1136 
1137   // Forward iteration
1138  public:
1139   // Iterate over all oop fields in the oop maps.
1140   template <typename T, class OopClosureType>
1141   inline void oop_oop_iterate_oop_maps(oop obj, OopClosureType* closure);
1142 
1143   // Iterate over all oop fields and metadata.
1144   template <typename T, class OopClosureType>
1145   inline void oop_oop_iterate(oop obj, OopClosureType* closure);
1146 
1147   // Iterate over all oop fields in one oop map.
1148   template <typename T, class OopClosureType>
1149   inline void oop_oop_iterate_oop_map(OopMapBlock* map, oop obj, OopClosureType* closure);
1150 
1151 
1152   // Reverse iteration
1153   // Iterate over all oop fields and metadata.
1154   template <typename T, class OopClosureType>
1155   inline void oop_oop_iterate_reverse(oop obj, OopClosureType* closure);
1156 
1157  private:
1158   // Iterate over all oop fields in the oop maps.
1159   template <typename T, class OopClosureType>
1160   inline void oop_oop_iterate_oop_maps_reverse(oop obj, OopClosureType* closure);
1161 
1162   // Iterate over all oop fields in one oop map.
1163   template <typename T, class OopClosureType>
1164   inline void oop_oop_iterate_oop_map_reverse(OopMapBlock* map, oop obj, OopClosureType* closure);
1165 
1166 
1167   // Bounded range iteration
1168  public:
1169   // Iterate over all oop fields in the oop maps.
1170   template <typename T, class OopClosureType>
1171   inline void oop_oop_iterate_oop_maps_bounded(oop obj, OopClosureType* closure, MemRegion mr);
1172 
1173   // Iterate over all oop fields and metadata.
1174   template <typename T, class OopClosureType>
1175   inline void oop_oop_iterate_bounded(oop obj, OopClosureType* closure, MemRegion mr);
1176 
1177  private:
1178   // Iterate over all oop fields in one oop map.
1179   template <typename T, class OopClosureType>
1180   inline void oop_oop_iterate_oop_map_bounded(OopMapBlock* map, oop obj, OopClosureType* closure, MemRegion mr);
1181 
1182 
1183  public:
1184   u2 idnum_allocated_count() const      { return _idnum_allocated_count; }
1185 
1186 private:
1187   // initialization state
1188   void set_init_state(ClassState state);
1189   void set_rewritten()                  { _misc_flags.set_rewritten(true); }
1190   void set_init_thread(JavaThread *thread)  {
1191     assert((thread == JavaThread::current() && _init_thread == nullptr) ||
1192            (thread == nullptr && _init_thread == JavaThread::current()), "Only one thread is allowed to own initialization");
1193     AtomicAccess::store(&_init_thread, thread);
1194   }
1195 
1196   jmethodID* methods_jmethod_ids_acquire() const;
1197   void release_set_methods_jmethod_ids(jmethodID* jmeths);
1198   // This nulls out obsolete jmethodIDs for all methods in 'klass'.
1199   static void clear_obsolete_jmethod_ids(InstanceKlass* klass);
1200   jmethodID update_jmethod_id(jmethodID* jmeths, Method* method, int idnum);
1201 
1202 public:
1203   // Lock for (1) initialization; (2) access to the ConstantPool of this class.
1204   // Must be one per class and it has to be a VM internal object so java code
1205   // cannot lock it (like the mirror).
1206   // It has to be an object not a Mutex because it's held through java calls.
1207   oop init_lock() const;
1208 
1209   // Returns the array class for the n'th dimension
1210   virtual ArrayKlass* array_klass(int n, TRAPS);
1211   virtual ArrayKlass* array_klass_or_null(int n);
1212 
1213   // Returns the array class with this class as element type
1214   virtual ArrayKlass* array_klass(TRAPS);
1215   virtual ArrayKlass* array_klass_or_null();
1216 
1217   static void clean_initialization_error_table();
1218 private:
1219   void fence_and_clear_init_lock();
1220 
1221   bool link_class_impl                           (TRAPS);
1222   bool verify_code                               (TRAPS);
1223   void initialize_impl                           (TRAPS);
1224   void initialize_super_interfaces               (TRAPS);
1225 
1226   void add_initialization_error(JavaThread* current, Handle exception);
1227   oop get_initialization_error(JavaThread* current);
1228 
1229   // find a local method (returns null if not found)
1230   Method* find_method_impl(const Symbol* name,
1231                            const Symbol* signature,
1232                            OverpassLookupMode overpass_mode,
1233                            StaticLookupMode static_mode,
1234                            PrivateLookupMode private_mode) const;
1235 
1236   static Method* find_method_impl(const Array<Method*>* methods,
1237                                   const Symbol* name,
1238                                   const Symbol* signature,
1239                                   OverpassLookupMode overpass_mode,
1240                                   StaticLookupMode static_mode,
1241                                   PrivateLookupMode private_mode);
1242 
1243 #if INCLUDE_JVMTI
1244   // RedefineClasses support
1245   void link_previous_versions(InstanceKlass* pv) { _previous_versions = pv; }
1246   void mark_newly_obsolete_methods(Array<Method*>* old_methods, int emcp_method_count);
1247 #endif
1248   // log class name to classlist
1249   void log_to_classlist() const;
1250 public:
1251 
1252 #if INCLUDE_CDS
1253   // CDS support - remove and restore oops from metadata. Oops are not shared.
1254   virtual void remove_unshareable_info();
1255   void remove_unshareable_flags();
1256   virtual void remove_java_mirror();
1257   virtual void restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, PackageEntry* pkg_entry, TRAPS);
1258   void init_shared_package_entry();
1259   bool can_be_verified_at_dumptime() const;
1260   void compute_has_loops_flag_for_methods();
1261 #endif
1262   bool     has_init_deps_processed() const { return _misc_flags.has_init_deps_processed(); }
1263   void set_has_init_deps_processed() {
1264     assert(is_initialized(), "");
1265     assert(!has_init_deps_processed(), "already set"); // one-off action
1266     _misc_flags.set_has_init_deps_processed(true);
1267   }
1268 
1269   u2 compute_modifier_flags() const;
1270 
1271 public:
1272   // JVMTI support
1273   jint jvmti_class_status() const;
1274 
1275   virtual void metaspace_pointers_do(MetaspaceClosure* iter);
1276 
1277  public:
1278   // Printing
1279   void print_on(outputStream* st) const;
1280   void print_value_on(outputStream* st) const;
1281 
1282   void oop_print_value_on(oop obj, outputStream* st);
1283 
1284   void oop_print_on      (oop obj, outputStream* st) { oop_print_on(obj, st, 0, 0); }
1285   void oop_print_on      (oop obj, outputStream* st, int indent = 0, int base_offset = 0);
1286 
1287 #ifndef PRODUCT
1288   void print_dependent_nmethods(bool verbose = false);
1289   bool is_dependent_nmethod(nmethod* nm);
1290   bool verify_itable_index(int index);
1291 #endif
1292 
1293   const char* internal_name() const;
1294 
1295   // Verification
1296   void verify_on(outputStream* st);
1297 
1298   void oop_verify_on(oop obj, outputStream* st);
1299 
1300   // Logging
1301   void print_class_load_logging(ClassLoaderData* loader_data,
1302                                 const ModuleEntry* module_entry,
1303                                 const ClassFileStream* cfs) const;
1304  private:
1305   void print_class_load_cause_logging() const;
1306   void print_class_load_helper(ClassLoaderData* loader_data,
1307                                const ModuleEntry* module_entry,
1308                                const ClassFileStream* cfs) const;
1309 };
1310 
1311 // for adding methods
1312 // UNSET_IDNUM return means no more ids available
1313 inline u2 InstanceKlass::next_method_idnum() {
1314   if (_idnum_allocated_count == ConstMethod::MAX_IDNUM) {
1315     return ConstMethod::UNSET_IDNUM; // no more ids available
1316   } else {
1317     return _idnum_allocated_count++;
1318   }
1319 }
1320 
1321 class PrintClassClosure : public KlassClosure {
1322 private:
1323   outputStream* _st;
1324   bool _verbose;
1325 public:
1326   PrintClassClosure(outputStream* st, bool verbose);
1327 
1328   void do_klass(Klass* k);
1329 };
1330 
1331 /* JNIid class for jfieldIDs only */
1332 class JNIid: public CHeapObj<mtClass> {
1333   friend class VMStructs;
1334  private:
1335   InstanceKlass*     _holder;
1336   JNIid*             _next;
1337   int                _offset;
1338 #ifdef ASSERT
1339   bool               _is_static_field_id;
1340 #endif
1341 
1342  public:
1343   // Accessors
1344   InstanceKlass* holder() const   { return _holder; }
1345   int offset() const              { return _offset; }
1346   JNIid* next()                   { return _next; }
1347   // Constructor
1348   JNIid(InstanceKlass* holder, int offset, JNIid* next);
1349   // Identifier lookup
1350   JNIid* find(int offset);
1351 
1352   bool find_local_field(fieldDescriptor* fd) {
1353     return InstanceKlass::cast(holder())->find_local_field_from_offset(offset(), true, fd);
1354   }
1355 
1356   static void deallocate(JNIid* id);
1357   // Debugging
1358 #ifdef ASSERT
1359   bool is_static_field_id() const { return _is_static_field_id; }
1360   void set_is_static_field_id()   { _is_static_field_id = true; }
1361 #endif
1362   void verify(InstanceKlass* holder);
1363 };
1364 
1365 // An iterator that's used to access the inner classes indices in the
1366 // InstanceKlass::_inner_classes array.
1367 class InnerClassesIterator : public StackObj {
1368  private:
1369   Array<jushort>* _inner_classes;
1370   int _length;
1371   int _idx;
1372  public:
1373 
1374   InnerClassesIterator(const InstanceKlass* k) {
1375     _inner_classes = k->inner_classes();
1376     if (k->inner_classes() != nullptr) {
1377       _length = _inner_classes->length();
1378       // The inner class array's length should be the multiple of
1379       // inner_class_next_offset if it only contains the InnerClasses
1380       // attribute data, or it should be
1381       // n*inner_class_next_offset+enclosing_method_attribute_size
1382       // if it also contains the EnclosingMethod data.
1383       assert((_length % InstanceKlass::inner_class_next_offset == 0 ||
1384               _length % InstanceKlass::inner_class_next_offset == InstanceKlass::enclosing_method_attribute_size),
1385              "just checking");
1386       // Remove the enclosing_method portion if exists.
1387       if (_length % InstanceKlass::inner_class_next_offset == InstanceKlass::enclosing_method_attribute_size) {
1388         _length -= InstanceKlass::enclosing_method_attribute_size;
1389       }
1390     } else {
1391       _length = 0;
1392     }
1393     _idx = 0;
1394   }
1395 
1396   int length() const {
1397     return _length;
1398   }
1399 
1400   void next() {
1401     _idx += InstanceKlass::inner_class_next_offset;
1402   }
1403 
1404   bool done() const {
1405     return (_idx >= _length);
1406   }
1407 
1408   u2 inner_class_info_index() const {
1409     return _inner_classes->at(
1410                _idx + InstanceKlass::inner_class_inner_class_info_offset);
1411   }
1412 
1413   void set_inner_class_info_index(u2 index) {
1414     _inner_classes->at_put(
1415                _idx + InstanceKlass::inner_class_inner_class_info_offset, index);
1416   }
1417 
1418   u2 outer_class_info_index() const {
1419     return _inner_classes->at(
1420                _idx + InstanceKlass::inner_class_outer_class_info_offset);
1421   }
1422 
1423   void set_outer_class_info_index(u2 index) {
1424     _inner_classes->at_put(
1425                _idx + InstanceKlass::inner_class_outer_class_info_offset, index);
1426   }
1427 
1428   u2 inner_name_index() const {
1429     return _inner_classes->at(
1430                _idx + InstanceKlass::inner_class_inner_name_offset);
1431   }
1432 
1433   void set_inner_name_index(u2 index) {
1434     _inner_classes->at_put(
1435                _idx + InstanceKlass::inner_class_inner_name_offset, index);
1436   }
1437 
1438   u2 inner_access_flags() const {
1439     return _inner_classes->at(
1440                _idx + InstanceKlass::inner_class_access_flags_offset);
1441   }
1442 };
1443 
1444 // Iterator over class hierarchy under a particular class. Implements depth-first pre-order traversal.
1445 // Usage:
1446 //  for (ClassHierarchyIterator iter(root_klass); !iter.done(); iter.next()) {
1447 //    Klass* k = iter.klass();
1448 //    ...
1449 //  }
1450 class ClassHierarchyIterator : public StackObj {
1451  private:
1452   InstanceKlass* _root;
1453   Klass*         _current;
1454   bool           _visit_subclasses;
1455 
1456  public:
1457   ClassHierarchyIterator(InstanceKlass* root) : _root(root), _current(root), _visit_subclasses(true) {
1458     assert(_root == _current, "required"); // initial state
1459   }
1460 
1461   bool done() {
1462     return (_current == nullptr);
1463   }
1464 
1465   // Make a step iterating over the class hierarchy under the root class.
1466   // Skips subclasses if requested.
1467   void next();
1468 
1469   Klass* klass() {
1470     assert(!done(), "sanity");
1471     return _current;
1472   }
1473 
1474   // Skip subclasses of the current class.
1475   void skip_subclasses() {
1476     _visit_subclasses = false;
1477   }
1478 };
1479 
1480 #endif // SHARE_OOPS_INSTANCEKLASS_HPP