luau/Analysis/include/Luau/Subtyping.h
vegorov-rbx ce9414cb98
Sync to upstream/release/592 (#1018)
* AST queries at position where function name is will now return
AstExprLocal
* Lexer performance has been slightly improved
* Fixed incorrect string singleton autocomplete suggestions (fixes #858)
* Improved parsing error messages
* Fixed crash on null pointer access in unification (fixes #1017)
* Native code support is enabled by default and `native=1`
(make)/`LUAU_NATIVE` (CMake)/`-DLUA_CUSTOM_EXECUTION` configuration is
no longer required

New typechecker:
* New subtyping check can now handle generic functions and tables
(including those that contain cycles)

Native code generation:
* Loops with non-numeric parameters are now handled by VM to streamline
native code
* Array size check can be optimized away in SETLIST
* On failure, CodeGen::compile returns a reason
* Fixed clobbering of non-volatile xmm registers on Windows
2023-08-25 10:23:55 -07:00

104 lines
3.3 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/UnifierSharedState.h"
#include <vector>
#include <optional>
namespace Luau
{
template<typename A, typename B>
struct TryPair;
struct InternalErrorReporter;
class Normalizer;
struct NormalizedType;
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);
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 FunctionType* subFunction, const FunctionType* superFunction);
SubtypingResult isSubtype_(const NormalizedType* subNorm, const NormalizedType* superNorm);
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