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Java example source code file (fieldDescriptor.hpp)

This example Java source code file (fieldDescriptor.hpp) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

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Java - Java tags/keywords

accessflags, annotationarray, basictype, constantpool, debug_only, fieldinfo, fieldtype\:\:basic_type, instanceklass, product_return, share_vm_runtime_fielddescriptor_hpp, symbol, the, value_obj_class_spec

The fieldDescriptor.hpp Java example source code

/*
 * Copyright (c) 1997, 2013, 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_VM_RUNTIME_FIELDDESCRIPTOR_HPP
#define SHARE_VM_RUNTIME_FIELDDESCRIPTOR_HPP

#include "oops/constantPool.hpp"
#include "oops/symbol.hpp"
#include "runtime/fieldType.hpp"
#include "utilities/accessFlags.hpp"
#include "utilities/constantTag.hpp"

// A fieldDescriptor describes the attributes of a single field (instance or class variable).
// It needs the class constant pool to work (because it only holds indices into the pool
// rather than the actual info).

class fieldDescriptor VALUE_OBJ_CLASS_SPEC {
 private:
  AccessFlags         _access_flags;
  int                 _index; // the field index
  constantPoolHandle  _cp;

  // update the access_flags for the field in the klass
  void update_klass_field_access_flag() {
    InstanceKlass* ik = field_holder();
    ik->field(index())->set_access_flags(_access_flags.as_short());
  }

  FieldInfo* field() const {
    InstanceKlass* ik = field_holder();
    return ik->field(_index);
  }

 public:
  fieldDescriptor() {
    DEBUG_ONLY(_index = badInt);
  }
  fieldDescriptor(InstanceKlass* ik, int index) {
    DEBUG_ONLY(_index = badInt);
    reinitialize(ik, index);
  }
  Symbol* name() const {
    return field()->name(_cp);
  }
  Symbol* signature() const {
    return field()->signature(_cp);
  }
  InstanceKlass* field_holder()   const    { return _cp->pool_holder(); }
  ConstantPool* constants()       const    { return _cp(); }
  AccessFlags access_flags()      const    { return _access_flags; }
  oop loader()                    const;
  // Offset (in words) of field from start of instanceOop / Klass*
  int offset()                    const    { return field()->offset(); }
  Symbol* generic_signature()     const;
  int index()                     const    { return _index; }
  AnnotationArray* annotations()  const;
  AnnotationArray* type_annotations()  const;

  // Initial field value
  bool has_initial_value()        const    { return field()->initval_index() != 0; }
  int initial_value_index()       const    { return field()->initval_index(); }
  constantTag initial_value_tag() const;  // The tag will return true on one of is_int(), is_long(), is_single(), is_double()
  jint int_initial_value()        const;
  jlong long_initial_value()      const;
  jfloat float_initial_value()    const;
  jdouble double_initial_value()  const;
  oop string_initial_value(TRAPS) const;

  // Field signature type
  BasicType field_type()          const    { return FieldType::basic_type(signature()); }

  // Access flags
  bool is_public()                const    { return access_flags().is_public(); }
  bool is_private()               const    { return access_flags().is_private(); }
  bool is_protected()             const    { return access_flags().is_protected(); }
  bool is_package_private()       const    { return !is_public() && !is_private() && !is_protected(); }

  bool is_static()                const    { return access_flags().is_static(); }
  bool is_final()                 const    { return access_flags().is_final(); }
  bool is_volatile()              const    { return access_flags().is_volatile(); }
  bool is_transient()             const    { return access_flags().is_transient(); }

  bool is_synthetic()             const    { return access_flags().is_synthetic(); }

  bool is_field_access_watched()  const    { return access_flags().is_field_access_watched(); }
  bool is_field_modification_watched() const
                                           { return access_flags().is_field_modification_watched(); }
  bool has_generic_signature()    const    { return access_flags().field_has_generic_signature(); }

  void set_is_field_access_watched(const bool value) {
    _access_flags.set_is_field_access_watched(value);
    update_klass_field_access_flag();
  }

  void set_is_field_modification_watched(const bool value) {
    _access_flags.set_is_field_modification_watched(value);
    update_klass_field_access_flag();
  }

  // Initialization
  void reinitialize(InstanceKlass* ik, int index);

  // Print
  void print() { print_on(tty); }
  void print_on(outputStream* st) const         PRODUCT_RETURN;
  void print_on_for(outputStream* st, oop obj)  PRODUCT_RETURN;
  void verify() const                           PRODUCT_RETURN;
};

#endif // SHARE_VM_RUNTIME_FIELDDESCRIPTOR_HPP

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