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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/codegen/machine-type.h"
#include "src/compiler/types.h"
#include "src/objects/feedback-vector.h"
#include "src/objects/field-index.h"
#include "src/objects/map.h"
#include "src/objects/objects.h"
#include "src/zone/zone-containers.h"
namespace v8 {
namespace internal {
// Forward declarations.
class Factory;
namespace compiler {
// Forward declarations.
class CompilationDependencies;
class CompilationDependency;
class ElementAccessFeedback;
class JSHeapBroker;
class TypeCache;
struct ConstFieldInfo;
std::ostream& operator<<(std::ostream&, AccessMode);
// This class encapsulates all information required to access a certain element.
class ElementAccessInfo final {
public:
ElementAccessInfo(ZoneVector<Handle<Map>>&& receiver_maps,
ElementsKind elements_kind, Zone* zone);
ElementsKind elements_kind() const { return elements_kind_; }
ZoneVector<Handle<Map>> const& receiver_maps() const {
return receiver_maps_;
}
ZoneVector<Handle<Map>> const& transition_sources() const {
return transition_sources_;
}
void AddTransitionSource(Handle<Map> map) {
CHECK_EQ(receiver_maps_.size(), 1);
transition_sources_.push_back(map);
}
private:
ElementsKind elements_kind_;
ZoneVector<Handle<Map>> receiver_maps_;
ZoneVector<Handle<Map>> transition_sources_;
};
// 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,
kDataField,
kDataConstant,
kAccessorConstant,
kModuleExport,
kStringLength
};
static PropertyAccessInfo NotFound(Zone* zone, Handle<Map> receiver_map,
MaybeHandle<JSObject> holder);
static PropertyAccessInfo DataField(
Zone* zone, Handle<Map> receiver_map,
ZoneVector<CompilationDependency const*>&& unrecorded_dependencies,
FieldIndex field_index, Representation field_representation,
Type field_type, Handle<Map> field_owner_map,
MaybeHandle<Map> field_map = MaybeHandle<Map>(),
MaybeHandle<JSObject> holder = MaybeHandle<JSObject>(),
MaybeHandle<Map> transition_map = MaybeHandle<Map>());
static PropertyAccessInfo DataConstant(
Zone* zone, Handle<Map> receiver_map,
ZoneVector<CompilationDependency const*>&& unrecorded_dependencies,
FieldIndex field_index, Representation field_representation,
Type field_type, Handle<Map> field_owner_map, MaybeHandle<Map> field_map,
MaybeHandle<JSObject> holder,
MaybeHandle<Map> transition_map = MaybeHandle<Map>());
static PropertyAccessInfo AccessorConstant(Zone* zone,
Handle<Map> receiver_map,
Handle<Object> constant,
MaybeHandle<JSObject> holder);
static PropertyAccessInfo ModuleExport(Zone* zone, Handle<Map> receiver_map,
Handle<Cell> cell);
static PropertyAccessInfo StringLength(Zone* zone, Handle<Map> receiver_map);
static PropertyAccessInfo Invalid(Zone* zone);
bool Merge(PropertyAccessInfo const* that, AccessMode access_mode,
Zone* zone) V8_WARN_UNUSED_RESULT;
void RecordDependencies(CompilationDependencies* dependencies);
bool IsInvalid() const { return kind() == kInvalid; }
bool IsNotFound() const { return kind() == kNotFound; }
bool IsDataField() const { return kind() == kDataField; }
bool IsDataConstant() const { return kind() == kDataConstant; }
bool IsAccessorConstant() const { return kind() == kAccessorConstant; }
bool IsModuleExport() const { return kind() == kModuleExport; }
bool IsStringLength() const { return kind() == kStringLength; }
bool HasTransitionMap() const { return !transition_map().is_null(); }
ConstFieldInfo GetConstFieldInfo() const;
Kind kind() const { return kind_; }
MaybeHandle<JSObject> holder() const {
// TODO(neis): There was a CHECK here that tries to protect against
// using the access info without recording its dependencies first.
// Find a more suitable place for it.
return holder_;
}
MaybeHandle<Map> transition_map() const { return transition_map_; }
Handle<Object> constant() const { return constant_; }
FieldIndex field_index() const { return field_index_; }
Type field_type() const { return field_type_; }
Representation field_representation() const { return field_representation_; }
MaybeHandle<Map> field_map() const { return field_map_; }
ZoneVector<Handle<Map>> const& receiver_maps() const {
return receiver_maps_;
}
private:
explicit PropertyAccessInfo(Zone* zone);
PropertyAccessInfo(Zone* zone, Kind kind, MaybeHandle<JSObject> holder,
ZoneVector<Handle<Map>>&& receiver_maps);
PropertyAccessInfo(Zone* zone, Kind kind, MaybeHandle<JSObject> holder,
Handle<Object> constant,
ZoneVector<Handle<Map>>&& receiver_maps);
PropertyAccessInfo(Kind kind, MaybeHandle<JSObject> holder,
MaybeHandle<Map> transition_map, FieldIndex field_index,
Representation field_representation, Type field_type,
Handle<Map> field_owner_map, MaybeHandle<Map> field_map,
ZoneVector<Handle<Map>>&& receiver_maps,
ZoneVector<CompilationDependency const*>&& dependencies);
Kind kind_;
ZoneVector<Handle<Map>> receiver_maps_;
ZoneVector<CompilationDependency const*> unrecorded_dependencies_;
Handle<Object> constant_;
MaybeHandle<Map> transition_map_;
MaybeHandle<JSObject> holder_;
FieldIndex field_index_;
Representation field_representation_;
Type field_type_;
MaybeHandle<Map> field_owner_map_;
MaybeHandle<Map> field_map_;
};
// Factory class for {ElementAccessInfo}s and {PropertyAccessInfo}s.
class AccessInfoFactory final {
public:
AccessInfoFactory(JSHeapBroker* broker, CompilationDependencies* dependencies,
Zone* zone);
base::Optional<ElementAccessInfo> ComputeElementAccessInfo(
Handle<Map> map, AccessMode access_mode) const;
bool ComputeElementAccessInfos(
ElementAccessFeedback const& feedback,
ZoneVector<ElementAccessInfo>* access_infos) const;
PropertyAccessInfo ComputePropertyAccessInfo(Handle<Map> map,
Handle<Name> name,
AccessMode access_mode) const;
// Convenience wrapper around {ComputePropertyAccessInfo} for multiple maps.
void ComputePropertyAccessInfos(
MapHandles const& maps, Handle<Name> name, AccessMode access_mode,
ZoneVector<PropertyAccessInfo>* access_infos) const;
// Merge as many of the given {infos} as possible and record any dependencies.
// Return false iff any of them was invalid, in which case no dependencies are
// recorded.
// TODO(neis): Make access_mode part of access info?
bool FinalizePropertyAccessInfos(
ZoneVector<PropertyAccessInfo> infos, AccessMode access_mode,
ZoneVector<PropertyAccessInfo>* result) const;
// Merge the given {infos} to a single one and record any dependencies. If the
// merge is not possible, the result has kind {kInvalid} and no dependencies
// are recorded.
PropertyAccessInfo FinalizePropertyAccessInfosAsOne(
ZoneVector<PropertyAccessInfo> infos, AccessMode access_mode) const;
private:
base::Optional<ElementAccessInfo> ConsolidateElementLoad(
ElementAccessFeedback const& feedback) const;
PropertyAccessInfo LookupSpecialFieldAccessor(Handle<Map> map,
Handle<Name> name) const;
PropertyAccessInfo LookupTransition(Handle<Map> map, Handle<Name> name,
MaybeHandle<JSObject> holder) const;
PropertyAccessInfo ComputeDataFieldAccessInfo(Handle<Map> receiver_map,
Handle<Map> map,
MaybeHandle<JSObject> holder,
int descriptor,
AccessMode access_mode) const;
PropertyAccessInfo ComputeAccessorDescriptorAccessInfo(
Handle<Map> receiver_map, Handle<Name> name, Handle<Map> map,
MaybeHandle<JSObject> holder, int descriptor,
AccessMode access_mode) const;
void MergePropertyAccessInfos(ZoneVector<PropertyAccessInfo> infos,
AccessMode access_mode,
ZoneVector<PropertyAccessInfo>* result) const;
CompilationDependencies* dependencies() const { return dependencies_; }
JSHeapBroker* broker() const { return broker_; }
Isolate* isolate() const;
Zone* zone() const { return zone_; }
JSHeapBroker* const broker_;
CompilationDependencies* const dependencies_;
TypeCache const* 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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