1 /*

     2  * Copyright (c) 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

    21  * questions.

    22  *

    23  */

    24 

    25 #ifndef SHARE_VM_OOPS_FIELDSTREAMS_HPP

    26 #define SHARE_VM_OOPS_FIELDSTREAMS_HPP

    27 

    28 #include "oops/instanceKlass.hpp"

    29 #include "oops/fieldInfo.hpp"

    30 

    31 // The is the base class for iteration over the fields array

    32 // describing the declared fields in the class.  Several subclasses

    33 // are provided depending on the kind of iteration required.  The

    34 // JavaFieldStream is for iterating over regular Java fields and it

    35 // generally the preferred iterator.  InternalFieldStream only

    36 // iterates over fields that have been injected by the JVM.

    37 // AllFieldStream exposes all fields and should only be used in rare

    38 // cases.

    39 class FieldStreamBase : public StackObj {

    40  protected:

    41   typeArrayHandle     _fields;

    42   constantPoolHandle  _constants;

    43   int                 _index;

    44   int                 _limit;

    45 

    46   FieldInfo* field() const { return FieldInfo::from_field_array(_fields(), _index); }

    47 

    48   FieldStreamBase(typeArrayHandle fields, constantPoolHandle constants, int start, int limit) {

    49     _fields = fields;

    50     _constants = constants;

    51     _index = start;

    52     _limit = limit;

    53   }

    54 

    55   FieldStreamBase(typeArrayHandle fields, constantPoolHandle constants) {

    56     _fields = fields;

    57     _constants = constants;

    58     _index = 0;

    59     _limit = fields->length() / FieldInfo::field_slots;

    60   }

    61 

    62  public:

    63   FieldStreamBase(instanceKlass* klass) {

    64     _fields = klass->fields();

    65     _constants = klass->constants();

    66     _index = 0;

    67     _limit = klass->java_fields_count();

    68   }

    69   FieldStreamBase(instanceKlassHandle klass) {

    70     _fields = klass->fields();

    71     _constants = klass->constants();

    72     _index = 0;

    73     _limit = klass->java_fields_count();

    74   }

    75 

    76   // accessors

    77   int index() const                 { return _index; }

    78 

    79   void next() { _index += 1; }

    80   bool done() const { return _index >= _limit; }

    81 

    82   // Accessors for current field

    83   AccessFlags access_flags() const {

    84     AccessFlags flags;

    85     flags.set_flags(field()->access_flags());

    86     return flags;

    87   }

    88 

    89   void set_access_flags(u2 flags) const {

    90     field()->set_access_flags(flags);

    91   }

    92 

    93   void set_access_flags(AccessFlags flags) const {

    94     set_access_flags(flags.as_short());

    95   }

    96 

    97   Symbol* name() const {

    98     return field()->name(_constants);

    99   }

   100 

   101   Symbol* signature() const {

   102     return field()->signature(_constants);

   103   }

   104 

   105   Symbol* generic_signature() const {

   106     return field()->generic_signature(_constants);

   107   }

   108 

   109   int offset() const {

   110     return field()->offset();

   111   }

   112 

   113   void set_offset(int offset) {

   114     field()->set_offset(offset);

   115   }

   116 };

   117 

   118 // Iterate over only the internal fields

   119 class JavaFieldStream : public FieldStreamBase {

   120  public:

   121   JavaFieldStream(instanceKlass* k):      FieldStreamBase(k->fields(), k->constants(), 0, k->java_fields_count()) {}

   122   JavaFieldStream(instanceKlassHandle k): FieldStreamBase(k->fields(), k->constants(), 0, k->java_fields_count()) {}

   123 

   124   int name_index() const {

   125     assert(!field()->is_internal(), "regular only");

   126     return field()->name_index();

   127   }

   128   void set_name_index(int index) {

   129     assert(!field()->is_internal(), "regular only");

   130     field()->set_name_index(index);

   131   }

   132   int signature_index() const {

   133     assert(!field()->is_internal(), "regular only");

   134     return field()->signature_index();

   135   }

   136   void set_signature_index(int index) {

   137     assert(!field()->is_internal(), "regular only");

   138     field()->set_signature_index(index);

   139   }

   140   int generic_signature_index() const {

   141     assert(!field()->is_internal(), "regular only");

   142     return field()->generic_signature_index();

   143   }

   144   void set_generic_signature_index(int index) {

   145     assert(!field()->is_internal(), "regular only");

   146     field()->set_generic_signature_index(index);

   147   }

   148   int initval_index() const {

   149     assert(!field()->is_internal(), "regular only");

   150     return field()->initval_index();

   151   }

   152   void set_initval_index(int index) {

   153     assert(!field()->is_internal(), "regular only");

   154     return field()->set_initval_index(index);

   155   }

   156 };

   157 

   158 

   159 // Iterate over only the internal fields

   160 class InternalFieldStream : public FieldStreamBase {

   161  public:

   162   InternalFieldStream(instanceKlass* k):      FieldStreamBase(k->fields(), k->constants(), k->java_fields_count(), k->all_fields_count()) {}

   163   InternalFieldStream(instanceKlassHandle k): FieldStreamBase(k->fields(), k->constants(), k->java_fields_count(), k->all_fields_count()) {}

   164 };

   165 

   166 

   167 class AllFieldStream : public FieldStreamBase {

   168  public:

   169   AllFieldStream(typeArrayHandle fields, constantPoolHandle constants): FieldStreamBase(fields, constants) {}

   170   AllFieldStream(instanceKlass* k):      FieldStreamBase(k->fields(), k->constants()) {}

   171   AllFieldStream(instanceKlassHandle k): FieldStreamBase(k->fields(), k->constants()) {}

   172 };

   173 

   174 #endif // SHARE_VM_OOPS_FIELDSTREAMS_HPP