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// Copyright 2015 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_COMPILER_ACCESS_INFO_H_
#define V8_COMPILER_ACCESS_INFO_H_
#include <iosfwd>
#include "src/field-index.h"
#include "src/objects.h"
#include "src/zone-containers.h"
namespace v8 {
namespace internal {
// Forward declarations.
class CompilationDependencies;
class Factory;
class TypeCache;
namespace compiler {
// Whether we are loading a property or storing to a property.
enum class AccessMode { kLoad, kStore };
std::ostream& operator<<(std::ostream&, AccessMode);
// Mapping of transition source to transition target.
typedef std::vector<std::pair<Handle<Map>, Handle<Map>>> MapTransitionList;
// This class encapsulates all information required to access a certain element.
class ElementAccessInfo final {
public:
ElementAccessInfo();
ElementAccessInfo(Type* receiver_type, ElementsKind elements_kind,
MaybeHandle<JSObject> holder);
MaybeHandle<JSObject> holder() const { return holder_; }
ElementsKind elements_kind() const { return elements_kind_; }
Type* receiver_type() const { return receiver_type_; }
MapTransitionList& transitions() { return transitions_; }
MapTransitionList const& transitions() const { return transitions_; }
private:
ElementsKind elements_kind_;
MaybeHandle<JSObject> holder_;
Type* receiver_type_;
MapTransitionList transitions_;
};
// Additional checks that need to be perform for data field accesses.
enum class FieldCheck : uint8_t {
// No additional checking needed.
kNone,
// Check that the [[ViewedArrayBuffer]] of {JSArrayBufferView}s
// was not neutered.
kJSArrayBufferViewBufferNotNeutered,
};
// This class encapsulates all information required to access a certain
// object property, either on the object itself or on the prototype chain.
class PropertyAccessInfo final {
public:
enum Kind { kInvalid, kNotFound, kDataConstant, kDataField };
static PropertyAccessInfo NotFound(Type* receiver_type,
MaybeHandle<JSObject> holder);
static PropertyAccessInfo DataConstant(Type* receiver_type,
Handle<Object> constant,
MaybeHandle<JSObject> holder);
static PropertyAccessInfo DataField(
Type* receiver_type, FieldIndex field_index, Type* field_type,
FieldCheck field_check = FieldCheck::kNone,
MaybeHandle<JSObject> holder = MaybeHandle<JSObject>(),
MaybeHandle<Map> transition_map = MaybeHandle<Map>());
PropertyAccessInfo();
bool IsNotFound() const { return kind() == kNotFound; }
bool IsDataConstant() const { return kind() == kDataConstant; }
bool IsDataField() const { return kind() == kDataField; }
bool HasTransitionMap() const { return !transition_map().is_null(); }
Kind kind() const { return kind_; }
MaybeHandle<JSObject> holder() const { return holder_; }
MaybeHandle<Map> transition_map() const { return transition_map_; }
Handle<Object> constant() const { return constant_; }
FieldCheck field_check() const { return field_check_; }
FieldIndex field_index() const { return field_index_; }
Type* field_type() const { return field_type_; }
Type* receiver_type() const { return receiver_type_; }
private:
PropertyAccessInfo(MaybeHandle<JSObject> holder, Type* receiver_type);
PropertyAccessInfo(MaybeHandle<JSObject> holder, Handle<Object> constant,
Type* receiver_type);
PropertyAccessInfo(MaybeHandle<JSObject> holder,
MaybeHandle<Map> transition_map, FieldIndex field_index,
FieldCheck field_check, Type* field_type,
Type* receiver_type);
Kind kind_;
Type* receiver_type_;
Handle<Object> constant_;
MaybeHandle<Map> transition_map_;
MaybeHandle<JSObject> holder_;
FieldIndex field_index_;
FieldCheck field_check_;
Type* field_type_;
};
// Factory class for {ElementAccessInfo}s and {PropertyAccessInfo}s.
class AccessInfoFactory final {
public:
AccessInfoFactory(CompilationDependencies* dependencies,
Handle<Context> native_context, Zone* zone);
bool ComputeElementAccessInfo(Handle<Map> map, AccessMode access_mode,
ElementAccessInfo* access_info);
bool ComputeElementAccessInfos(MapHandleList const& maps,
AccessMode access_mode,
ZoneVector<ElementAccessInfo>* access_infos);
bool ComputePropertyAccessInfo(Handle<Map> map, Handle<Name> name,
AccessMode access_mode,
PropertyAccessInfo* access_info);
bool ComputePropertyAccessInfos(MapHandleList const& maps, Handle<Name> name,
AccessMode access_mode,
ZoneVector<PropertyAccessInfo>* access_infos);
private:
bool LookupSpecialFieldAccessor(Handle<Map> map, Handle<Name> name,
PropertyAccessInfo* access_info);
bool LookupTransition(Handle<Map> map, Handle<Name> name,
MaybeHandle<JSObject> holder,
PropertyAccessInfo* access_info);
CompilationDependencies* dependencies() const { return dependencies_; }
Factory* factory() const;
Isolate* isolate() const { return isolate_; }
Handle<Context> native_context() const { return native_context_; }
Zone* zone() const { return zone_; }
CompilationDependencies* const dependencies_;
Handle<Context> const native_context_;
Isolate* const isolate_;
TypeCache const& type_cache_;
Zone* const zone_;
DISALLOW_COPY_AND_ASSIGN(AccessInfoFactory);
};
} // namespace compiler
} // namespace internal
} // namespace v8
#endif // V8_COMPILER_ACCESS_INFO_H_
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