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