libjava/gcj/field.h

   1 // field.h - Header file for fieldID instances.  -*- c++ -*-
   2
   3 /* Copyright (C) 1998, 1999  Cygnus Solutions
   4
   5    This file is part of libgcj.
   6
   7 This software is copyrighted work licensed under the terms of the
   8 Libgcj License.  Please consult the file "LIBGCJ_LICENSE" for
   9 details.  */
  10
  11 #ifndef __GCJ_FIELD_H__
  12 #define __GCJ_FIELD_H__
  13
  14 #include <java/lang/Class.h>
  15 #include <java/lang/reflect/Field.h>
  16
  17 #define _Jv_FIELD_UNRESOLVED_FLAG       0x8000
  18 #define _Jv_FIELD_CONSTANT_VALUE        0x4000
  19
  20 struct _Jv_Field
  21 {
  22 #ifndef COMPACT_FIELDS
  23   struct _Jv_Utf8Const* name;
  24 #endif
  25
  26   /* The type of the field, if isResolved().
  27      If !isResolved():  The fields's signature as a (Utf8Const*). */
  28   jclass                type;
  29
  30   _Jv_ushort            flags;
  31
  32 #ifdef COMPACT_FIELDS
  33   short                 nameIndex;  /* ofsfet in class's name table */
  34 #else
  35   _Jv_ushort            bsize;  /* not really needed ... */
  36 #endif
  37
  38   union {
  39     int                 boffset;  /* offset in bytes for instance field */
  40     void*               addr;  /* address of static field */
  41   } u;
  42
  43 #ifdef __cplusplus
  44   jboolean isResolved ()
  45   { return ! (flags & _Jv_FIELD_UNRESOLVED_FLAG); }
  46
  47   public:
  48
  49   int getOffset () { return u.boffset; }
  50
  51   jobject getObjectField (jobject obj)
  52   { return *(jobject *)((char *)obj + getOffset ()); }
  53
  54   jfieldID getNextInstanceField () { return this + 1; }
  55
  56   jboolean isRef ()
  57     {
  58       if (!isResolved ())
  59         {
  60           char first = ((_Jv_Utf8Const*)type)->data[0];
  61           return first == '[' || first == 'L';
  62         }
  63       else
  64         {
  65           return ! type->isPrimitive ();
  66         }
  67     }
  68
  69   // FIXME - may need to mask off internal flags.
  70   int getModifiers() { return flags; }
  71
  72 #ifdef COMPACT_FIELDS
  73   _Jv_Utf8Const * getNameUtf8Const (jclass cls)
  74   { return clas->fieldNames + nameIndex; }
  75 #else
  76   _Jv_Utf8Const * getNameUtf8Const (jclass) { return name; }
  77 #endif
  78 #endif
  79 };
  80
  81 #ifdef __cplusplus
  82 inline jbyte
  83 _Jv_GetStaticByteField (jclass, _Jv_Field* field)
  84 {
  85   return * (jbyte *) field->u.addr;
  86 }
  87
  88 inline jshort
  89 _Jv_GetStaticShortField (jclass, _Jv_Field* field)
  90 {
  91   return * (jshort *) field->u.addr;
  92 }
  93
  94 inline jint
  95 _Jv_GetStaticIntField (jclass, _Jv_Field* field)
  96 {
  97   return * (jint *) field->u.addr;
  98 }
  99
 100 inline jlong
 101 _Jv_GetStaticLongField (jclass, _Jv_Field* field)
 102 {
 103   return * (jlong *) field->u.addr;
 104 }
 105
 106 inline jobject
 107 _Jv_GetObjectField (jobject obj, _Jv_Field* field)
 108 {
 109   return field->getObjectField (obj);
 110 }
 111
 112 inline jbyte
 113 _Jv_GetByteField (jobject obj, _Jv_Field* field)
 114 {
 115   return * (jbyte *) ((char*) obj + field->getOffset ());
 116 }
 117
 118 inline jshort
 119 _Jv_GetShortField (jobject obj, _Jv_Field* field)
 120 {
 121   return * (jshort *) ((char*) obj + field->getOffset ());
 122 }
 123 inline jint
 124 _Jv_GetIntField (jobject obj, _Jv_Field* field)
 125 {
 126   return * (jint *) ((char*) obj + field->getOffset ());
 127 }
 128 inline jlong
 129 _Jv_GetLongField (jobject obj, _Jv_Field* field)
 130 {
 131   return * (jlong *) ((char*) obj + field->getOffset ());
 132 }
 133
 134 extern inline jfieldID
 135 _Jv_FromReflectedField (java::lang::reflect::Field *field)
 136 {
 137   return (jfieldID) ((char *) field->declaringClass->fields + field->offset);
 138 }
 139
 140
 141 #ifdef __GCJ_CNI_H__
 142 extern inline jfieldID
 143 JvGetFirstInstanceField (jclass klass)
 144 {
 145   return &(klass->fields[klass->static_field_count]);
 146 }
 147
 148 extern inline jint
 149 JvNumInstanceFields (jclass klass)
 150 {
 151   return klass->field_count - klass->static_field_count;
 152 }
 153
 154 extern inline jboolean
 155 JvFieldIsRef (jfieldID field)
 156 {
 157   return field->isRef ();
 158 }
 159
 160 extern inline jobject
 161 JvGetObjectField (jobject obj, _Jv_Field* field)
 162 {
 163   return _Jv_GetObjectField (obj, field);
 164 }
 165 #endif /* defined (__GCJ_CNI_H__) */
 166
 167 #endif
 168
 169 #endif /* __GCJ_FIELD_H */