1 /*
   2  * Copyright (c) 1997, 2011, 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
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  23  */
  24 
  25 #ifndef SHARE_VM_RUNTIME_FIELDDESCRIPTOR_HPP
  26 #define SHARE_VM_RUNTIME_FIELDDESCRIPTOR_HPP
  27 
  28 #include "oops/constantPoolOop.hpp"
  29 #include "oops/klassOop.hpp"
  30 #include "oops/oop.inline.hpp"
  31 #include "oops/symbol.hpp"
  32 #include "runtime/fieldType.hpp"
  33 #include "utilities/accessFlags.hpp"
  34 #include "utilities/constantTag.hpp"
  35 
  36 // A fieldDescriptor describes the attributes of a single field (instance or class variable).
  37 // It needs the class constant pool to work (because it only holds indices into the pool
  38 // rather than the actual info).
  39 
  40 class fieldDescriptor VALUE_OBJ_CLASS_SPEC {
  41  private:
  42   AccessFlags         _access_flags;
  43   int                 _index; // the field index
  44   constantPoolHandle  _cp;
  45 
  46   // update the access_flags for the field in the klass
  47   void update_klass_field_access_flag() {
  48     instanceKlass* ik = instanceKlass::cast(field_holder());
  49     ik->field(index())->set_access_flags(_access_flags.as_short());
  50   }
  51 
  52   FieldInfo* field() const {
  53     instanceKlass* ik = instanceKlass::cast(field_holder());
  54     return ik->field(_index);
  55   }
  56 
  57  public:
  58   Symbol* name() const {
  59     return field()->name(_cp);
  60   }
  61   Symbol* signature() const {
  62     return field()->signature(_cp);
  63   }
  64   klassOop field_holder() const        { return _cp->pool_holder(); }
  65   constantPoolOop constants() const    { return _cp(); }
  66   AccessFlags access_flags() const     { return _access_flags; }
  67   oop loader() const;
  68   // Offset (in words) of field from start of instanceOop / klassOop
  69   int offset() const                   { return field()->offset(); }
  70   Symbol* generic_signature() const;
  71   int index() const                    { return _index; }
  72   typeArrayOop annotations() const;
  73 
  74   // Initial field value
  75   bool has_initial_value() const          { return field()->initval_index() != 0; }
  76   int initial_value_index() const         { return field()->initval_index(); }
  77   constantTag initial_value_tag() const;  // The tag will return true on one of is_int(), is_long(), is_single(), is_double()
  78   jint        int_initial_value() const;
  79   jlong       long_initial_value() const;
  80   jfloat      float_initial_value() const;
  81   jdouble     double_initial_value() const;
  82   oop         string_initial_value(TRAPS) const;
  83 
  84   // Field signature type
  85   BasicType field_type() const            { return FieldType::basic_type(signature()); }
  86 
  87   // Access flags
  88   bool is_public() const                  { return access_flags().is_public(); }
  89   bool is_private() const                 { return access_flags().is_private(); }
  90   bool is_protected() const               { return access_flags().is_protected(); }
  91   bool is_package_private() const         { return !is_public() && !is_private() && !is_protected(); }
  92 
  93   bool is_static() const                  { return access_flags().is_static(); }
  94   bool is_final() const                   { return access_flags().is_final(); }
  95   bool is_volatile() const                { return access_flags().is_volatile(); }
  96   bool is_transient() const               { return access_flags().is_transient(); }
  97 
  98   bool is_synthetic() const               { return access_flags().is_synthetic(); }
  99 
 100   bool is_field_access_watched() const    { return access_flags().is_field_access_watched(); }
 101   bool is_field_modification_watched() const
 102                                           { return access_flags().is_field_modification_watched(); }
 103   bool has_generic_signature() const      { return access_flags().field_has_generic_signature(); }
 104 
 105   void set_is_field_access_watched(const bool value) {
 106     _access_flags.set_is_field_access_watched(value);
 107     update_klass_field_access_flag();
 108   }
 109 
 110   void set_is_field_modification_watched(const bool value) {
 111     _access_flags.set_is_field_modification_watched(value);
 112     update_klass_field_access_flag();
 113   }
 114 
 115   // Initialization
 116   void initialize(klassOop k, int index);
 117 
 118   // Print
 119   void print_on(outputStream* st) const         PRODUCT_RETURN;
 120   void print_on_for(outputStream* st, oop obj)  PRODUCT_RETURN;
 121 };
 122 
 123 #endif // SHARE_VM_RUNTIME_FIELDDESCRIPTOR_HPP