luau/Analysis/include/Luau/Subtyping.h
vegorov-rbx c7c986b996
Sync to upstream/release/594 (#1036)
* Fixed `Frontend::markDirty` not working on modules that were not
typechecked yet
* Fixed generic variadic function unification succeeding when it should
have reported an error

New Type Solver:
* Implemented semantic subtyping check for function types

Native Code Generation:
* Improved performance of numerical loops with a constant step
* Simplified IR for `bit32.extract` calls extracting first/last bits
* Improved performance of NaN checks
2023-09-07 17:13:49 -07:00

123 lines
4.5 KiB
C++

// This file is part of the Luau programming language and is licensed under MIT License; see LICENSE.txt for details
#pragma once
#include "Luau/Type.h"
#include "Luau/TypePack.h"
#include "Luau/UnifierSharedState.h"
#include <vector>
#include <optional>
namespace Luau
{
template<typename A, typename B>
struct TryPair;
struct InternalErrorReporter;
class TypeIds;
class Normalizer;
struct NormalizedType;
struct NormalizedClassType;
struct NormalizedFunctionType;
struct SubtypingResult
{
// Did the test succeed?
bool isSubtype = false;
bool isErrorSuppressing = false;
bool normalizationTooComplex = false;
// If so, what constraints are implied by this relation?
// If not, what happened?
void andAlso(const SubtypingResult& other);
void orElse(const SubtypingResult& other);
// Only negates the `isSubtype`.
static SubtypingResult negate(const SubtypingResult& result);
static SubtypingResult all(const std::vector<SubtypingResult>& results);
static SubtypingResult any(const std::vector<SubtypingResult>& results);
};
struct Subtyping
{
NotNull<BuiltinTypes> builtinTypes;
NotNull<TypeArena> arena;
NotNull<Normalizer> normalizer;
NotNull<InternalErrorReporter> iceReporter;
enum class Variance
{
Covariant,
Contravariant
};
Variance variance = Variance::Covariant;
struct GenericBounds
{
DenseHashSet<TypeId> lowerBound{nullptr};
DenseHashSet<TypeId> upperBound{nullptr};
};
/*
* When we encounter a generic over the course of a subtyping test, we need
* to tentatively map that generic onto a type on the other side.
*/
DenseHashMap<TypeId, GenericBounds> mappedGenerics{nullptr};
DenseHashMap<TypePackId, TypePackId> mappedGenericPacks{nullptr};
using SeenSet = std::unordered_set<std::pair<TypeId, TypeId>, TypeIdPairHash>;
SeenSet seenTypes;
// TODO cache
// TODO cyclic types
// TODO recursion limits
SubtypingResult isSubtype(TypeId subTy, TypeId superTy);
SubtypingResult isSubtype(TypePackId subTy, TypePackId superTy);
private:
SubtypingResult isSubtype_(TypeId subTy, TypeId superTy);
SubtypingResult isSubtype_(TypePackId subTy, TypePackId superTy);
template<typename SubTy, typename SuperTy>
SubtypingResult isSubtype_(const TryPair<const SubTy*, const SuperTy*>& pair);
SubtypingResult isSubtype_(TypeId subTy, const UnionType* superUnion);
SubtypingResult isSubtype_(const UnionType* subUnion, TypeId superTy);
SubtypingResult isSubtype_(TypeId subTy, const IntersectionType* superIntersection);
SubtypingResult isSubtype_(const IntersectionType* subIntersection, TypeId superTy);
SubtypingResult isSubtype_(const PrimitiveType* subPrim, const PrimitiveType* superPrim);
SubtypingResult isSubtype_(const SingletonType* subSingleton, const PrimitiveType* superPrim);
SubtypingResult isSubtype_(const SingletonType* subSingleton, const SingletonType* superSingleton);
SubtypingResult isSubtype_(const TableType* subTable, const TableType* superTable);
SubtypingResult isSubtype_(const MetatableType* subMt, const MetatableType* superMt);
SubtypingResult isSubtype_(const MetatableType* subMt, const TableType* superTable);
SubtypingResult isSubtype_(const ClassType* subClass, const ClassType* superClass);
SubtypingResult isSubtype_(const ClassType* subClass, const TableType* superTable); // Actually a class <: shape.
SubtypingResult isSubtype_(const FunctionType* subFunction, const FunctionType* superFunction);
SubtypingResult isSubtype_(const PrimitiveType* subPrim, const TableType* superTable);
SubtypingResult isSubtype_(const SingletonType* subSingleton, const TableType* superTable);
SubtypingResult isSubtype_(const NormalizedType* subNorm, const NormalizedType* superNorm);
SubtypingResult isSubtype_(const NormalizedClassType& subClass, const NormalizedClassType& superClass, const TypeIds& superTables);
SubtypingResult isSubtype_(const NormalizedFunctionType& subFunction, const NormalizedFunctionType& superFunction);
SubtypingResult isSubtype_(const TypeIds& subTypes, const TypeIds& superTypes);
SubtypingResult isSubtype_(const VariadicTypePack* subVariadic, const VariadicTypePack* superVariadic);
bool bindGeneric(TypeId subTp, TypeId superTp);
bool bindGeneric(TypePackId subTp, TypePackId superTp);
template <typename T, typename Container>
TypeId makeAggregateType(const Container& container, TypeId orElse);
[[noreturn]]
void unexpected(TypePackId tp);
};
} // namespace Luau