luau/Analysis/include/Luau/Unifier2.h
Andy Friesen 0fa6a51c91
Sync to upstream/release/629 (#1290)
### What's new

* Implemented parsing logic for attributes
* Added `lua_setuserdatametatable` and `lua_getuserdatametatable` C API
methods for a faster userdata metatable fetch compared to
`luaL_getmetatable`. Note that metatable reference has to still be
pinned in memory!

### New Solver

* Further improvement to the assignment inference logic
* Fix many bugs surrounding constraint dispatch order

### Native Codegen

* Add IR lowering hooks for custom host userdata types
* Add IR to create new tagged userdata objects
* Remove outdated NativeState

---
### Internal Contributors

Co-authored-by: Aaron Weiss <aaronweiss@roblox.com>
Co-authored-by: Alexander McCord <amccord@roblox.com>
Co-authored-by: Andy Friesen <afriesen@roblox.com>
Co-authored-by: Aviral Goel <agoel@roblox.com>
Co-authored-by: Vighnesh Vijay <vvijay@roblox.com>
Co-authored-by: Vyacheslav Egorov <vegorov@roblox.com>
2024-06-07 10:51:12 -07:00

110 lines
4 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/Constraint.h"
#include "Luau/DenseHash.h"
#include "Luau/NotNull.h"
#include "Luau/TypeCheckLimits.h"
#include "Luau/TypeFwd.h"
#include "Luau/TypePairHash.h"
#include <optional>
#include <vector>
#include <utility>
namespace Luau
{
struct InternalErrorReporter;
struct Scope;
struct TypeArena;
enum class OccursCheckResult
{
Pass,
Fail
};
struct Unifier2
{
NotNull<TypeArena> arena;
NotNull<BuiltinTypes> builtinTypes;
NotNull<Scope> scope;
NotNull<InternalErrorReporter> ice;
TypeCheckLimits limits;
DenseHashSet<std::pair<TypeId, TypeId>, TypePairHash> seenTypePairings{{nullptr, nullptr}};
DenseHashSet<std::pair<TypePackId, TypePackId>, TypePairHash> seenTypePackPairings{{nullptr, nullptr}};
DenseHashMap<TypeId, std::vector<TypeId>> expandedFreeTypes{nullptr};
// Mapping from generic types to free types to be used in instantiation.
DenseHashMap<TypeId, TypeId> genericSubstitutions{nullptr};
// Mapping from generic type packs to `TypePack`s of free types to be used in instantiation.
DenseHashMap<TypePackId, TypePackId> genericPackSubstitutions{nullptr};
int recursionCount = 0;
int recursionLimit = 0;
std::vector<ConstraintV> incompleteSubtypes;
// null if not in a constraint solving context
DenseHashSet<const void*>* uninhabitedTypeFamilies;
Unifier2(NotNull<TypeArena> arena, NotNull<BuiltinTypes> builtinTypes, NotNull<Scope> scope, NotNull<InternalErrorReporter> ice);
Unifier2(NotNull<TypeArena> arena, NotNull<BuiltinTypes> builtinTypes, NotNull<Scope> scope, NotNull<InternalErrorReporter> ice,
DenseHashSet<const void*>* uninhabitedTypeFamilies);
/** Attempt to commit the subtype relation subTy <: superTy to the type
* graph.
*
* @returns true if successful.
*
* Note that incoherent types can and will successfully be unified. We stop
* when we *cannot know* how to relate the provided types, not when doing so
* would narrow something down to never or broaden it to unknown.
*
* Presently, the only way unification can fail is if we attempt to bind one
* free TypePack to another and encounter an occurs check violation.
*/
bool unify(TypeId subTy, TypeId superTy);
bool unifyFreeWithType(TypeId subTy, TypeId superTy);
bool unify(TypeId subTy, const FunctionType* superFn);
bool unify(const UnionType* subUnion, TypeId superTy);
bool unify(TypeId subTy, const UnionType* superUnion);
bool unify(const IntersectionType* subIntersection, TypeId superTy);
bool unify(TypeId subTy, const IntersectionType* superIntersection);
bool unify(TableType* subTable, const TableType* superTable);
bool unify(const MetatableType* subMetatable, const MetatableType* superMetatable);
bool unify(const AnyType* subAny, const FunctionType* superFn);
bool unify(const FunctionType* subFn, const AnyType* superAny);
bool unify(const AnyType* subAny, const TableType* superTable);
bool unify(const TableType* subTable, const AnyType* superAny);
// TODO think about this one carefully. We don't do unions or intersections of type packs
bool unify(TypePackId subTp, TypePackId superTp);
std::optional<TypeId> generalize(TypeId ty);
private:
/**
* @returns simplify(left | right)
*/
TypeId mkUnion(TypeId left, TypeId right);
/**
* @returns simplify(left & right)
*/
TypeId mkIntersection(TypeId left, TypeId right);
// Returns true if needle occurs within haystack already. ie if we bound
// needle to haystack, would a cyclic type result?
OccursCheckResult occursCheck(DenseHashSet<TypeId>& seen, TypeId needle, TypeId haystack);
// Returns true if needle occurs within haystack already. ie if we bound
// needle to haystack, would a cyclic TypePack result?
OccursCheckResult occursCheck(DenseHashSet<TypePackId>& seen, TypePackId needle, TypePackId haystack);
};
} // namespace Luau