runtime/mirror/art_field.cc

/*
 * Copyright (C) 2011 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.
 */

#include "art_field.h"

#include "art_field-inl.h"
#include "gc/accounting/card_table-inl.h"
#include "object-inl.h"
#include "object_array-inl.h"
#include "object_utils.h"
#include "runtime.h"
#include "scoped_thread_state_change.h"
#include "utils.h"
#include "well_known_classes.h"

namespace art {
namespace mirror {

// TODO: Get global references for these
Class* ArtField::java_lang_reflect_ArtField_ = NULL;

ArtField* ArtField::FromReflectedField(const ScopedObjectAccessAlreadyRunnable& soa,
                                       jobject jlr_field) {
  mirror::ArtField* f = soa.DecodeField(WellKnownClasses::java_lang_reflect_Field_artField);
  mirror::ArtField* field = f->GetObject(soa.Decode<mirror::Object*>(jlr_field))->AsArtField();
  DCHECK(field != nullptr);
  return field;
}

void ArtField::SetClass(Class* java_lang_reflect_ArtField) {
  CHECK(java_lang_reflect_ArtField_ == NULL);
  CHECK(java_lang_reflect_ArtField != NULL);
  java_lang_reflect_ArtField_ = java_lang_reflect_ArtField;
}

void ArtField::ResetClass() {
  CHECK(java_lang_reflect_ArtField_ != NULL);
  java_lang_reflect_ArtField_ = NULL;
}

void ArtField::SetOffset(MemberOffset num_bytes) {
  DCHECK(GetDeclaringClass()->IsLoaded() || GetDeclaringClass()->IsErroneous());
  if (kIsDebugBuild && Runtime::Current()->IsCompiler() &&
      !Runtime::Current()->UseCompileTimeClassPath()) {
    Primitive::Type type = GetTypeAsPrimitiveType();
    if (type == Primitive::kPrimDouble || type == Primitive::kPrimLong) {
      DCHECK_ALIGNED(num_bytes.Uint32Value(), 8);
    }
  }
  // Not called within a transaction.
  SetField32<false>(OFFSET_OF_OBJECT_MEMBER(ArtField, offset_), num_bytes.Uint32Value());
}

void ArtField::VisitRoots(RootCallback* callback, void* arg) {
  if (java_lang_reflect_ArtField_ != nullptr) {
    callback(reinterpret_cast<mirror::Object**>(&java_lang_reflect_ArtField_), arg, 0,
             kRootStickyClass);
  }
}

// TODO: we could speed up the search if fields are ordered by offsets.
ArtField* ArtField::FindInstanceFieldWithOffset(mirror::Class* klass, uint32_t field_offset) {
  DCHECK(klass != nullptr);
  ObjectArray<ArtField>* instance_fields = klass->GetIFields();
  if (instance_fields != nullptr) {
    for (int32_t i = 0, e = instance_fields->GetLength(); i < e; ++i) {
      mirror::ArtField* field = instance_fields->GetWithoutChecks(i);
      if (field->GetOffset().Uint32Value() == field_offset) {
        return field;
      }
    }
  }
  // We did not find field in the class: look into superclass.
  if (klass->GetSuperClass() != NULL) {
    return FindInstanceFieldWithOffset(klass->GetSuperClass(), field_offset);
  } else {
    return nullptr;
  }
}

}  // namespace mirror
}  // namespace art