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// Copyright 2012 the V8 project authors. All rights reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following
// disclaimer in the documentation and/or other materials provided
// with the distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#ifndef V8_PROPERTY_DETAILS_H_
#define V8_PROPERTY_DETAILS_H_
#include "../include/v8.h"
#include "allocation.h"
#include "utils.h"
// Ecma-262 3rd 8.6.1
enum PropertyAttributes {
NONE = v8::None,
READ_ONLY = v8::ReadOnly,
DONT_ENUM = v8::DontEnum,
DONT_DELETE = v8::DontDelete,
ABSENT = 16 // Used in runtime to indicate a property is absent.
// ABSENT can never be stored in or returned from a descriptor's attributes
// bitfield. It is only used as a return value meaning the attributes of
// a non-existent property.
};
namespace v8 {
namespace internal {
class Smi;
// Type of properties.
// Order of properties is significant.
// Must fit in the BitField PropertyDetails::TypeField.
// A copy of this is in mirror-debugger.js.
enum PropertyType {
NORMAL = 0, // only in slow mode
FIELD = 1, // only in fast mode
CONSTANT_FUNCTION = 2, // only in fast mode
CALLBACKS = 3,
HANDLER = 4, // only in lookup results, not in descriptors
INTERCEPTOR = 5, // only in lookup results, not in descriptors
// All properties before MAP_TRANSITION are real.
MAP_TRANSITION = 6, // only in fast mode
ELEMENTS_TRANSITION = 7,
CONSTANT_TRANSITION = 8, // only in fast mode
NULL_DESCRIPTOR = 9, // only in fast mode
// There are no IC stubs for NULL_DESCRIPTORS. Therefore,
// NULL_DESCRIPTOR can be used as the type flag for IC stubs for
// nonexistent properties.
NONEXISTENT = NULL_DESCRIPTOR
};
// PropertyDetails captures type and attributes for a property.
// They are used both in property dictionaries and instance descriptors.
class PropertyDetails BASE_EMBEDDED {
public:
PropertyDetails(PropertyAttributes attributes,
PropertyType type,
int index = 0) {
ASSERT(TypeField::is_valid(type));
ASSERT(AttributesField::is_valid(attributes));
ASSERT(StorageField::is_valid(index));
value_ = TypeField::encode(type)
| AttributesField::encode(attributes)
| StorageField::encode(index);
ASSERT(type == this->type());
ASSERT(attributes == this->attributes());
ASSERT(index == this->index());
}
// Conversion for storing details as Object*.
explicit inline PropertyDetails(Smi* smi);
inline Smi* AsSmi();
PropertyType type() { return TypeField::decode(value_); }
PropertyAttributes attributes() { return AttributesField::decode(value_); }
int index() { return StorageField::decode(value_); }
inline PropertyDetails AsDeleted();
static bool IsValidIndex(int index) {
return StorageField::is_valid(index);
}
bool IsReadOnly() { return (attributes() & READ_ONLY) != 0; }
bool IsDontDelete() { return (attributes() & DONT_DELETE) != 0; }
bool IsDontEnum() { return (attributes() & DONT_ENUM) != 0; }
bool IsDeleted() { return DeletedField::decode(value_) != 0;}
// Bit fields in value_ (type, shift, size). Must be public so the
// constants can be embedded in generated code.
class TypeField: public BitField<PropertyType, 0, 4> {};
class AttributesField: public BitField<PropertyAttributes, 4, 3> {};
class DeletedField: public BitField<uint32_t, 7, 1> {};
class StorageField: public BitField<uint32_t, 8, 32-8> {};
static const int kInitialIndex = 1;
private:
uint32_t value_;
};
} } // namespace v8::internal
#endif // V8_PROPERTY_DETAILS_H_
|
