tagged-impl.h | Explore in Territory

// Copyright 2019 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef V8_OBJECTS_TAGGED_IMPL_H_
#define V8_OBJECTS_TAGGED_IMPL_H_

#include "include/v8-internal.h"
#include "src/base/export-template.h"
#include "src/base/macros.h"
#include "src/common/checks.h"
#include "src/common/globals.h"
#include "src/common/ptr-compr.h"

namespace v8 {
namespace internal {

#if defined(V8_EXTERNAL_CODE_SPACE) || defined(V8_ENABLE_SANDBOX)
// When V8_EXTERNAL_CODE_SPACE or V8_ENABLE_SANDBOX is enabled, comparing
// objects in the code- or trusted space with "regular" objects by looking only
// at compressed values is not correct. Full pointers must be compared instead.
bool V8_EXPORT_PRIVATE CheckObjectComparisonAllowed(Address a, Address b);
#endif

// An TaggedImpl is a base class for Object (which is either a Smi or a strong
// reference to a HeapObject) and Tagged<MaybeObject> (which is either a Smi, a
// strong reference to a HeapObject, a weak reference to a HeapObject, or a
// cleared weak reference. This class provides storage and one canonical
// implementation of various predicates that check Smi and heap object tags'
// values and also take into account whether the tagged value is expected to be
// weak reference to a HeapObject or cleared weak reference.
template <HeapObjectReferenceType kRefType, typename StorageType>
class TaggedImpl { … };

// Prints this object without details.
template <HeapObjectReferenceType kRefType, typename StorageType>
EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE)
void ShortPrint(TaggedImpl<kRefType, StorageType> ptr, FILE* out = stdout);

// Prints this object without details to a message accumulator.
template <HeapObjectReferenceType kRefType, typename StorageType>
EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE)
void ShortPrint(TaggedImpl<kRefType, StorageType> ptr,
                StringStream* accumulator);

template <HeapObjectReferenceType kRefType, typename StorageType>
EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE)
void ShortPrint(TaggedImpl<kRefType, StorageType> ptr, std::ostream& os);

#ifdef OBJECT_PRINT
template <HeapObjectReferenceType kRefType, typename StorageType>
EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE)
void Print(TaggedImpl<kRefType, StorageType> ptr);
template <HeapObjectReferenceType kRefType, typename StorageType>
EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE)
void Print(TaggedImpl<kRefType, StorageType> ptr, std::ostream& os);
#else
template <HeapObjectReferenceType kRefType, typename StorageType>
void Print(TaggedImpl<kRefType, StorageType> ptr) {
  ShortPrint(ptr);
}
template <HeapObjectReferenceType kRefType, typename StorageType>
void Print(TaggedImpl<kRefType, StorageType> ptr, std::ostream& os) {
  ShortPrint(ptr, os);
}
#endif

}  // namespace internal
}  // namespace v8

#endif  // V8_OBJECTS_TAGGED_IMPL_H_
chromium/v8/src/objects/tagged-impl.h
