runtime/mirror/field.h

/*
 * Copyright (C) 2015 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef ART_RUNTIME_MIRROR_FIELD_H_
#define ART_RUNTIME_MIRROR_FIELD_H_

#include "accessible_object.h"
#include "base/enums.h"
#include "dex/modifiers.h"
#include "dex/primitive.h"
#include "obj_ptr.h"
#include "object.h"
#include "read_barrier_option.h"

namespace art {

class ArtField;
struct FieldOffsets;
class ReflectiveValueVisitor;

namespace mirror {

class Class;
class String;

// C++ mirror of java.lang.reflect.Field.
class MANAGED Field : public AccessibleObject {
 public:
  ALWAYS_INLINE uint32_t GetDexFieldIndex() REQUIRES_SHARED(Locks::mutator_lock_) {
    return GetField32(OFFSET_OF_OBJECT_MEMBER(Field, dex_field_index_));
  }

  ObjPtr<mirror::Class> GetDeclaringClass() REQUIRES_SHARED(Locks::mutator_lock_);

  uint32_t GetAccessFlags() REQUIRES_SHARED(Locks::mutator_lock_) {
    return GetField32(OFFSET_OF_OBJECT_MEMBER(Field, access_flags_));
  }

  bool IsStatic() REQUIRES_SHARED(Locks::mutator_lock_) {
    return (GetAccessFlags() & kAccStatic) != 0;
  }

  bool IsFinal() REQUIRES_SHARED(Locks::mutator_lock_) {
    return (GetAccessFlags() & kAccFinal) != 0;
  }

  bool IsVolatile() REQUIRES_SHARED(Locks::mutator_lock_) {
    return (GetAccessFlags() & kAccVolatile) != 0;
  }

  ALWAYS_INLINE Primitive::Type GetTypeAsPrimitiveType() REQUIRES_SHARED(Locks::mutator_lock_);

  ObjPtr<mirror::Class> GetType() REQUIRES_SHARED(Locks::mutator_lock_);

  int32_t GetOffset() REQUIRES_SHARED(Locks::mutator_lock_) {
    return GetField32(OFFSET_OF_OBJECT_MEMBER(Field, offset_));
  }

  // Slow, try to use only for PrettyField and such. Set use-dex-cache to false to not utilize the
  // dex-cache when finding the art-field. This is useful for cases where the dex-cache might be
  // temporarally invalid.
  ArtField* GetArtField(bool use_dex_cache = true) REQUIRES_SHARED(Locks::mutator_lock_);

  template <PointerSize kPointerSize, bool kTransactionActive = false>
  static ObjPtr<mirror::Field> CreateFromArtField(Thread* self,
                                                  ArtField* field,
                                                  bool force_resolve)
      REQUIRES_SHARED(Locks::mutator_lock_) REQUIRES(!Roles::uninterruptible_);


  // Used to modify the target of this Field object, if required for structural redefinition or some
  // other purpose.
  void VisitTarget(ReflectiveValueVisitor* v) REQUIRES(Locks::mutator_lock_);

 private:
  // Padding required for matching alignment with the Java peer.
  uint8_t padding_[2];

  HeapReference<mirror::Class> declaring_class_;
  HeapReference<mirror::Class> type_;
  int32_t access_flags_;
  int32_t dex_field_index_;
  int32_t offset_;

  template<bool kTransactionActive>
  void SetDeclaringClass(ObjPtr<mirror::Class> c) REQUIRES_SHARED(Locks::mutator_lock_);

  template<bool kTransactionActive>
  void SetType(ObjPtr<mirror::Class> type) REQUIRES_SHARED(Locks::mutator_lock_);

  template<bool kTransactionActive>
  void SetAccessFlags(uint32_t flags) REQUIRES_SHARED(Locks::mutator_lock_) {
    SetField32<kTransactionActive>(OFFSET_OF_OBJECT_MEMBER(Field, access_flags_), flags);
  }

  template<bool kTransactionActive>
  void SetDexFieldIndex(uint32_t idx) REQUIRES_SHARED(Locks::mutator_lock_) {
    SetField32<kTransactionActive>(OFFSET_OF_OBJECT_MEMBER(Field, dex_field_index_), idx);
  }

  template<bool kTransactionActive>
  void SetOffset(uint32_t offset) REQUIRES_SHARED(Locks::mutator_lock_) {
    SetField32<kTransactionActive>(OFFSET_OF_OBJECT_MEMBER(Field, offset_), offset);
  }

  friend struct art::FieldOffsets;  // for verifying offset information
  DISALLOW_IMPLICIT_CONSTRUCTORS(Field);
};

}  // namespace mirror
}  // namespace art

#endif  // ART_RUNTIME_MIRROR_FIELD_H_