/*

 * Copyright (c) 1997, 2019, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 *

 */

#ifndef SHARE_OOPS_INSTANCEKLASS_HPP

#define SHARE_OOPS_INSTANCEKLASS_HPP

#include "classfile/classLoaderData.hpp"

#include "memory/referenceType.hpp"

#include "oops/annotations.hpp"

#include "oops/constMethod.hpp"

#include "oops/fieldInfo.hpp"

#include "oops/instanceOop.hpp"

#include "oops/klassVtable.hpp"

#include "runtime/handles.hpp"

#include "runtime/os.hpp"

#include "utilities/accessFlags.hpp"

#include "utilities/align.hpp"

#include "utilities/macros.hpp"

#if INCLUDE_JFR

#include "jfr/support/jfrKlassExtension.hpp"

#endif

// An InstanceKlass is the VM level representation of a Java class.

// It contains all information needed for at class at execution runtime.

//  InstanceKlass embedded field layout (after declared fields):

//    [EMBEDDED Java vtable             ] size in words = vtable_len

//    [EMBEDDED nonstatic oop-map blocks] size in words = nonstatic_oop_map_size

//      The embedded nonstatic oop-map blocks are short pairs (offset, length)

//      indicating where oops are located in instances of this klass.

//    [EMBEDDED implementor of the interface] only exist for interface

//    [EMBEDDED unsafe_anonymous_host klass] only exist for an unsafe anonymous class (JSR 292 enabled)

//    [EMBEDDED fingerprint       ] only if should_store_fingerprint()==true

// forward declaration for class -- see below for definition

#if INCLUDE_JVMTI

class BreakpointInfo;

#endif

class ClassFileParser;

class ClassFileStream;

class KlassDepChange;

class DependencyContext;

class fieldDescriptor;

class jniIdMapBase;

class JNIid;

class JvmtiCachedClassFieldMap;

class nmethodBucket;

class OopMapCache;

class InterpreterOopMap;

class PackageEntry;

class ModuleEntry;

// This is used in iterators below.

class FieldClosure: public StackObj {

public:

  virtual void do_field(fieldDescriptor* fd) = 0;

};

#ifndef PRODUCT

// Print fields.

// If "obj" argument to constructor is NULL, prints static fields, otherwise prints non-static fields.

class FieldPrinter: public FieldClosure {

   oop _obj;

   outputStream* _st;

 public:

   FieldPrinter(outputStream* st, oop obj = NULL) : _obj(obj), _st(st) {}

   void do_field(fieldDescriptor* fd);

};

#endif  // !PRODUCT

// Describes where oops are located in instances of this klass.

class OopMapBlock {

 public:

  // Byte offset of the first oop mapped by this block.

  int offset() const          { return _offset; }

  void set_offset(int offset) { _offset = offset; }

  // Number of oops in this block.

  uint count() const         { return _count; }

  void set_count(uint count) { _count = count; }

  // sizeof(OopMapBlock) in words.

  static const int size_in_words() {

    return align_up((int)sizeof(OopMapBlock), wordSize) >>

      LogBytesPerWord;

  }

 private:

  int  _offset;

  uint _count;

};

struct JvmtiCachedClassFileData;

class InstanceKlass: public Klass {

  friend class VMStructs;

  friend class JVMCIVMStructs;

  friend class ClassFileParser;

  friend class CompileReplay;

 public:

  static const KlassID ID = InstanceKlassID;

 protected:

  InstanceKlass(const ClassFileParser& parser, unsigned kind, KlassID id = ID);

 public:

  InstanceKlass() { assert(DumpSharedSpaces || UseSharedSpaces, "only for CDS"); }

  // See "The Java Virtual Machine Specification" section 2.16.2-5 for a detailed description

  // of the class loading & initialization procedure, and the use of the states.

  enum ClassState {

    allocated,                          // allocated (but not yet linked)

    loaded,                             // loaded and inserted in class hierarchy (but not linked yet)

    linked,                             // successfully linked/verified (but not initialized yet)

    being_initialized,                  // currently running class initializer

    fully_initialized,                  // initialized (successfull final state)

    initialization_error                // error happened during initialization

  };

 private:

  static InstanceKlass* allocate_instance_klass(const ClassFileParser& parser, TRAPS);

 protected:

  // If you add a new field that points to any metaspace object, you

  // must add this field to InstanceKlass::metaspace_pointers_do().

  // Annotations for this class

  Annotations*    _annotations;

  // Package this class is defined in

  PackageEntry*   _package_entry;

  // Array classes holding elements of this class.

  Klass* volatile _array_klasses;

  // Constant pool for this class.

  ConstantPool* _constants;

  // The InnerClasses attribute and EnclosingMethod attribute. The

  // _inner_classes is an array of shorts. If the class has InnerClasses

  // attribute, then the _inner_classes array begins with 4-tuples of shorts

  // [inner_class_info_index, outer_class_info_index,

  // inner_name_index, inner_class_access_flags] for the InnerClasses

  // attribute. If the EnclosingMethod attribute exists, it occupies the

  // last two shorts [class_index, method_index] of the array. If only

  // the InnerClasses attribute exists, the _inner_classes array length is

  // number_of_inner_classes * 4. If the class has both InnerClasses

  // and EnclosingMethod attributes the _inner_classes array length is

  // number_of_inner_classes * 4 + enclosing_method_attribute_size.

  Array<jushort>* _inner_classes;

  // The NestMembers attribute. An array of shorts, where each is a

  // class info index for the class that is a nest member. This data

  // has not been validated.

  Array<jushort>* _nest_members;

  // The NestHost attribute. The class info index for the class

  // that is the nest-host of this class. This data has not been validated.

  jushort _nest_host_index;

  // Resolved nest-host klass: either true nest-host or self if we are not nested.

  // By always being set it makes nest-member access checks simpler.

  InstanceKlass* _nest_host;

  // the source debug extension for this klass, NULL if not specified.

  // Specified as UTF-8 string without terminating zero byte in the classfile,

  // it is stored in the instanceklass as a NULL-terminated UTF-8 string

  const char*     _source_debug_extension;

  // Array name derived from this class which needs unreferencing

  // if this class is unloaded.

  Symbol*         _array_name;

  // Number of heapOopSize words used by non-static fields in this klass

  // (including inherited fields but after header_size()).

  int             _nonstatic_field_size;

  int             _static_field_size;    // number words used by static fields (oop and non-oop) in this klass

  // Constant pool index to the utf8 entry of the Generic signature,

  // or 0 if none.

  u2              _generic_signature_index;

  // Constant pool index to the utf8 entry for the name of source file

  // containing this klass, 0 if not specified.

  u2              _source_file_name_index;

  u2              _static_oop_field_count;// number of static oop fields in this klass

  u2              _java_fields_count;    // The number of declared Java fields

  int             _nonstatic_oop_map_size;// size in words of nonstatic oop map blocks

  int             _itable_len;           // length of Java itable (in words)

  // _is_marked_dependent can be set concurrently, thus cannot be part of the

  // _misc_flags.

  bool            _is_marked_dependent;  // used for marking during flushing and deoptimization

  bool            _is_being_redefined;   // used for locking redefinition

  // The low two bits of _misc_flags contains the kind field.

  // This can be used to quickly discriminate among the four kinds of

  // InstanceKlass.

  static const unsigned _misc_kind_field_size = 2;

  static const unsigned _misc_kind_field_pos  = 0;

  static const unsigned _misc_kind_field_mask = (1u << _misc_kind_field_size) - 1u;

  static const unsigned _misc_kind_other        = 0; // concrete InstanceKlass

  static const unsigned _misc_kind_reference    = 1; // InstanceRefKlass

  static const unsigned _misc_kind_class_loader = 2; // InstanceClassLoaderKlass

  static const unsigned _misc_kind_mirror       = 3; // InstanceMirrorKlass

  // Start after _misc_kind field.

  enum {

    _misc_rewritten                           = 1 << 2,  // methods rewritten.

    _misc_has_nonstatic_fields                = 1 << 3,  // for sizing with UseCompressedOops

    _misc_should_verify_class                 = 1 << 4,  // allow caching of preverification

    _misc_is_unsafe_anonymous                 = 1 << 5,  // has embedded _unsafe_anonymous_host field

    _misc_is_contended                        = 1 << 6,  // marked with contended annotation

    _misc_has_nonstatic_concrete_methods      = 1 << 7,  // class/superclass/implemented interfaces has non-static, concrete methods

    _misc_declares_nonstatic_concrete_methods = 1 << 8,  // directly declares non-static, concrete methods

    _misc_has_been_redefined                  = 1 << 9,  // class has been redefined

    _misc_has_passed_fingerprint_check        = 1 << 10, // when this class was loaded, the fingerprint computed from its

                                                         // code source was found to be matching the value recorded by AOT.

    _misc_is_scratch_class                    = 1 << 11, // class is the redefined scratch class

    _misc_is_shared_boot_class                = 1 << 12, // defining class loader is boot class loader

    _misc_is_shared_platform_class            = 1 << 13, // defining class loader is platform class loader

    _misc_is_shared_app_class                 = 1 << 14, // defining class loader is app class loader

    _misc_has_resolved_methods                = 1 << 15  // resolved methods table entries added for this class

  };

  u2 loader_type_bits() {

    return _misc_is_shared_boot_class|_misc_is_shared_platform_class|_misc_is_shared_app_class;

  }

  u2              _misc_flags;

  u2              _minor_version;        // minor version number of class file

  u2              _major_version;        // major version number of class file

  Thread*         _init_thread;          // Pointer to current thread doing initialization (to handle recursive initialization)

  OopMapCache*    volatile _oop_map_cache;   // OopMapCache for all methods in the klass (allocated lazily)

  JNIid*          _jni_ids;              // First JNI identifier for static fields in this class

  jmethodID*      volatile _methods_jmethod_ids;  // jmethodIDs corresponding to method_idnum, or NULL if none

  nmethodBucket*  volatile _dep_context;          // packed DependencyContext structure

  uint64_t        volatile _dep_context_last_cleaned;

  nmethod*        _osr_nmethods_head;    // Head of list of on-stack replacement nmethods for this class

#if INCLUDE_JVMTI

  BreakpointInfo* _breakpoints;          // bpt lists, managed by Method*

  // Linked instanceKlasses of previous versions

  InstanceKlass* _previous_versions;

  // JVMTI fields can be moved to their own structure - see 6315920

  // JVMTI: cached class file, before retransformable agent modified it in CFLH

  JvmtiCachedClassFileData* _cached_class_file;

#endif

  volatile u2     _idnum_allocated_count;         // JNI/JVMTI: increments with the addition of methods, old ids don't change

  // Class states are defined as ClassState (see above).

  // Place the _init_state here to utilize the unused 2-byte after

  // _idnum_allocated_count.

  u1              _init_state;                    // state of class

  u1              _reference_type;                // reference type

  u2              _this_class_index;              // constant pool entry

#if INCLUDE_JVMTI

  JvmtiCachedClassFieldMap* _jvmti_cached_class_field_map;  // JVMTI: used during heap iteration

#endif

  NOT_PRODUCT(int _verify_count;)  // to avoid redundant verifies

  // Method array.

  Array<Method*>* _methods;

  // Default Method Array, concrete methods inherited from interfaces

  Array<Method*>* _default_methods;

  // Interfaces (InstanceKlass*s) this class declares locally to implement.

  Array<InstanceKlass*>* _local_interfaces;

  // Interfaces (InstanceKlass*s) this class implements transitively.

  Array<InstanceKlass*>* _transitive_interfaces;

  // Int array containing the original order of method in the class file (for JVMTI).

  Array<int>*     _method_ordering;

  // Int array containing the vtable_indices for default_methods

  // offset matches _default_methods offset

  Array<int>*     _default_vtable_indices;

  // Instance and static variable information, starts with 6-tuples of shorts

  // [access, name index, sig index, initval index, low_offset, high_offset]

  // for all fields, followed by the generic signature data at the end of

  // the array. Only fields with generic signature attributes have the generic

  // signature data set in the array. The fields array looks like following:

  //

  // f1: [access, name index, sig index, initial value index, low_offset, high_offset]

  // f2: [access, name index, sig index, initial value index, low_offset, high_offset]

  //      ...

  // fn: [access, name index, sig index, initial value index, low_offset, high_offset]

  //     [generic signature index]

  //     [generic signature index]

  //     ...

  Array<u2>*      _fields;

  // embedded Java vtable follows here

  // embedded Java itables follows here

  // embedded static fields follows here

  // embedded nonstatic oop-map blocks follows here

  // embedded implementor of this interface follows here

  //   The embedded implementor only exists if the current klass is an

  //   iterface. The possible values of the implementor fall into following

  //   three cases:

  //     NULL: no implementor.

  //     A Klass* that's not itself: one implementor.

  //     Itself: more than one implementors.

  // embedded unsafe_anonymous_host klass follows here

  //   The embedded host klass only exists in an unsafe anonymous class for

  //   dynamic language support (JSR 292 enabled). The host class grants

  //   its access privileges to this class also. The host class is either

  //   named, or a previously loaded unsafe anonymous class. A non-anonymous class

  //   or an anonymous class loaded through normal classloading does not

  //   have this embedded field.

  //

  friend class SystemDictionary;

 public:

  u2 loader_type() {

    return _misc_flags & loader_type_bits();

  }

  bool is_shared_boot_class() const {

    return (_misc_flags & _misc_is_shared_boot_class) != 0;

  }

  bool is_shared_platform_class() const {

    return (_misc_flags & _misc_is_shared_platform_class) != 0;

  }

  bool is_shared_app_class() const {

    return (_misc_flags & _misc_is_shared_app_class) != 0;

  }

  void clear_class_loader_type() {

    _misc_flags &= ~loader_type_bits();

  }

  void set_class_loader_type(s2 loader_type);

  bool has_nonstatic_fields() const        {

    return (_misc_flags & _misc_has_nonstatic_fields) != 0;

  }

  void set_has_nonstatic_fields(bool b)    {

    if (b) {

      _misc_flags |= _misc_has_nonstatic_fields;

    } else {

      _misc_flags &= ~_misc_has_nonstatic_fields;

    }

  }

  // field sizes

  int nonstatic_field_size() const         { return _nonstatic_field_size; }

  void set_nonstatic_field_size(int size)  { _nonstatic_field_size = size; }

  int static_field_size() const            { return _static_field_size; }

  void set_static_field_size(int size)     { _static_field_size = size; }

  int static_oop_field_count() const       { return (int)_static_oop_field_count; }

  void set_static_oop_field_count(u2 size) { _static_oop_field_count = size; }

  // Java itable

  int  itable_length() const               { return _itable_len; }

  void set_itable_length(int len)          { _itable_len = len; }

  // array klasses

  Klass* array_klasses() const             { return _array_klasses; }

  inline Klass* array_klasses_acquire() const; // load with acquire semantics

  void set_array_klasses(Klass* k)         { _array_klasses = k; }

  inline void release_set_array_klasses(Klass* k); // store with release semantics

  // methods

  Array<Method*>* methods() const          { return _methods; }

  void set_methods(Array<Method*>* a)      { _methods = a; }

  Method* method_with_idnum(int idnum);

  Method* method_with_orig_idnum(int idnum);

  Method* method_with_orig_idnum(int idnum, int version);

  // method ordering

  Array<int>* method_ordering() const     { return _method_ordering; }

  void set_method_ordering(Array<int>* m) { _method_ordering = m; }

  void copy_method_ordering(const intArray* m, TRAPS);

  // default_methods

  Array<Method*>* default_methods() const  { return _default_methods; }

  void set_default_methods(Array<Method*>* a) { _default_methods = a; }

  // default method vtable_indices

  Array<int>* default_vtable_indices() const { return _default_vtable_indices; }

  void set_default_vtable_indices(Array<int>* v) { _default_vtable_indices = v; }

  Array<int>* create_new_default_vtable_indices(int len, TRAPS);

  // interfaces

  Array<InstanceKlass*>* local_interfaces() const          { return _local_interfaces; }

  void set_local_interfaces(Array<InstanceKlass*>* a)      {

    guarantee(_local_interfaces == NULL || a == NULL, "Just checking");

    _local_interfaces = a; }

  Array<InstanceKlass*>* transitive_interfaces() const     { return _transitive_interfaces; }

  void set_transitive_interfaces(Array<InstanceKlass*>* a) {

    guarantee(_transitive_interfaces == NULL || a == NULL, "Just checking");

    _transitive_interfaces = a;

  }

 private:

  friend class fieldDescriptor;

  FieldInfo* field(int index) const { return FieldInfo::from_field_array(_fields, index); }

 public:

  int     field_offset      (int index) const { return field(index)->offset(); }

  int     field_access_flags(int index) const { return field(index)->access_flags(); }

  Symbol* field_name        (int index) const { return field(index)->name(constants()); }

  Symbol* field_signature   (int index) const { return field(index)->signature(constants()); }

  // Number of Java declared fields

  int java_fields_count() const           { return (int)_java_fields_count; }

  Array<u2>* fields() const            { return _fields; }

  void set_fields(Array<u2>* f, u2 java_fields_count) {

    guarantee(_fields == NULL || f == NULL, "Just checking");

    _fields = f;

    _java_fields_count = java_fields_count;

  }

  // inner classes

  Array<u2>* inner_classes() const       { return _inner_classes; }

  void set_inner_classes(Array<u2>* f)   { _inner_classes = f; }

  // nest members

  Array<u2>* nest_members() const     { return _nest_members; }

  void set_nest_members(Array<u2>* m) { _nest_members = m; }

  // nest-host index

  jushort nest_host_index() const { return _nest_host_index; }

  void set_nest_host_index(u2 i)  { _nest_host_index = i; }

private:

  // Called to verify that k is a member of this nest - does not look at k's nest-host

  bool has_nest_member(InstanceKlass* k, TRAPS) const;

public:

  // Returns nest-host class, resolving and validating it if needed

  // Returns NULL if an exception occurs during loading, or validation fails

  InstanceKlass* nest_host(Symbol* validationException, TRAPS);

  // Check if this klass is a nestmate of k - resolves this nest-host and k's

  bool has_nestmate_access_to(InstanceKlass* k, TRAPS);

  enum InnerClassAttributeOffset {

    // From http://mirror.eng/products/jdk/1.1/docs/guide/innerclasses/spec/innerclasses.doc10.html#18814

    inner_class_inner_class_info_offset = 0,

    inner_class_outer_class_info_offset = 1,

    inner_class_inner_name_offset = 2,

    inner_class_access_flags_offset = 3,

    inner_class_next_offset = 4

  };

  enum EnclosingMethodAttributeOffset {

    enclosing_method_class_index_offset = 0,

    enclosing_method_method_index_offset = 1,

    enclosing_method_attribute_size = 2

  };

  // method override check

  bool is_override(const methodHandle& super_method, Handle targetclassloader, Symbol* targetclassname, TRAPS);

  // package

  PackageEntry* package() const     { return _package_entry; }

  ModuleEntry* module() const;

  bool in_unnamed_package() const   { return (_package_entry == NULL); }

  void set_package(PackageEntry* p) { _package_entry = p; }

  void set_package(ClassLoaderData* loader_data, TRAPS);

  bool is_same_class_package(const Klass* class2) const;

  bool is_same_class_package(oop other_class_loader, const Symbol* other_class_name) const;

  // find an enclosing class

  InstanceKlass* compute_enclosing_class(bool* inner_is_member, TRAPS) const;

  // Find InnerClasses attribute and return outer_class_info_index & inner_name_index.