luau/Analysis/include/Luau/Subtyping.h
vegorov-rbx d518d14b92
Sync to upstream/release/640 (#1374)
### What's new

* Fixed many of the false positive errors in indexing of table unions
and table intersections
* It is now possible to run custom checks over Luau AST during
typechecking by setting `customModuleCheck` in `FrontendOptions`
* Fixed codegen issue on arm, where number->vector cast could corrupt
that number value for the next time it's read

### New Solver

* `error` type now behaves as the bottom type during subtyping checks
* Fixed the scope that is used in subtyping with generic types
* Fixed `astOriginalCallTypes` table often used by LSP to match the old
solver

---

### Internal Contributors

Co-authored-by: Aaron Weiss <aaronweiss@roblox.com>
Co-authored-by: Andy Friesen <afriesen@roblox.com>
Co-authored-by: Vighnesh Vijay <vvijay@roblox.com>
Co-authored-by: Vyacheslav Egorov <vegorov@roblox.com>
2024-08-23 09:35:30 -07:00

297 lines
12 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/Set.h"
#include "Luau/TypeFwd.h"
#include "Luau/TypePairHash.h"
#include "Luau/TypePath.h"
#include "Luau/TypeFunction.h"
#include "Luau/TypeCheckLimits.h"
#include "Luau/DenseHash.h"
#include <vector>
#include <optional>
namespace Luau
{
template<typename A, typename B>
struct TryPair;
struct InternalErrorReporter;
class TypeIds;
class Normalizer;
struct NormalizedClassType;
struct NormalizedFunctionType;
struct NormalizedStringType;
struct NormalizedType;
struct Property;
struct Scope;
struct TableIndexer;
struct TypeArena;
struct TypeCheckLimits;
enum class SubtypingVariance
{
// Used for an empty key. Should never appear in actual code.
Invalid,
Covariant,
// This is used to identify cases where we have a covariant + a
// contravariant reason and we need to merge them.
Contravariant,
Invariant,
};
struct SubtypingReasoning
{
// The path, relative to the _root subtype_, where subtyping failed.
Path subPath;
// The path, relative to the _root supertype_, where subtyping failed.
Path superPath;
SubtypingVariance variance = SubtypingVariance::Covariant;
bool operator==(const SubtypingReasoning& other) const;
};
struct SubtypingReasoningHash
{
size_t operator()(const SubtypingReasoning& r) const;
};
using SubtypingReasonings = DenseHashSet<SubtypingReasoning, SubtypingReasoningHash>;
static const SubtypingReasoning kEmptyReasoning = SubtypingReasoning{TypePath::kEmpty, TypePath::kEmpty, SubtypingVariance::Invalid};
struct SubtypingResult
{
bool isSubtype = false;
bool normalizationTooComplex = false;
bool isCacheable = true;
ErrorVec errors;
/// The reason for isSubtype to be false. May not be present even if
/// isSubtype is false, depending on the input types.
SubtypingReasonings reasoning{kEmptyReasoning};
SubtypingResult& andAlso(const SubtypingResult& other);
SubtypingResult& orElse(const SubtypingResult& other);
SubtypingResult& withBothComponent(TypePath::Component component);
SubtypingResult& withSuperComponent(TypePath::Component component);
SubtypingResult& withSubComponent(TypePath::Component component);
SubtypingResult& withBothPath(TypePath::Path path);
SubtypingResult& withSubPath(TypePath::Path path);
SubtypingResult& withSuperPath(TypePath::Path path);
SubtypingResult& withErrors(ErrorVec& err);
SubtypingResult& withError(TypeError err);
// 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 SubtypingEnvironment
{
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};
/*
* See the test cyclic_tables_are_assumed_to_be_compatible_with_classes for
* details.
*
* An empty value is equivalent to a nonexistent key.
*/
DenseHashMap<TypeId, TypeId> substitutions{nullptr};
DenseHashMap<std::pair<TypeId, TypeId>, SubtypingResult, TypePairHash> ephemeralCache{{}};
/// Applies `mappedGenerics` to the given type.
/// This is used specifically to substitute for generics in type function instances.
std::optional<TypeId> applyMappedGenerics(NotNull<BuiltinTypes> builtinTypes, NotNull<TypeArena> arena, TypeId ty);
};
struct Subtyping
{
NotNull<BuiltinTypes> builtinTypes;
NotNull<TypeArena> arena;
NotNull<Normalizer> normalizer;
NotNull<InternalErrorReporter> iceReporter;
TypeCheckLimits limits;
enum class Variance
{
Covariant,
Contravariant
};
Variance variance = Variance::Covariant;
using SeenSet = Set<std::pair<TypeId, TypeId>, TypePairHash>;
SeenSet seenTypes{{}};
Subtyping(
NotNull<BuiltinTypes> builtinTypes,
NotNull<TypeArena> typeArena,
NotNull<Normalizer> normalizer,
NotNull<InternalErrorReporter> iceReporter
);
Subtyping(const Subtyping&) = delete;
Subtyping& operator=(const Subtyping&) = delete;
Subtyping(Subtyping&&) = default;
Subtyping& operator=(Subtyping&&) = default;
// Only used by unit tests to test that the cache works.
const DenseHashMap<std::pair<TypeId, TypeId>, SubtypingResult, TypePairHash>& peekCache() const
{
return resultCache;
}
// TODO cache
// TODO cyclic types
// TODO recursion limits
SubtypingResult isSubtype(TypeId subTy, TypeId superTy, NotNull<Scope> scope);
SubtypingResult isSubtype(TypePackId subTy, TypePackId superTy, NotNull<Scope> scope);
private:
DenseHashMap<std::pair<TypeId, TypeId>, SubtypingResult, TypePairHash> resultCache{{}};
SubtypingResult cache(SubtypingEnvironment& env, SubtypingResult res, TypeId subTy, TypeId superTy);
SubtypingResult isCovariantWith(SubtypingEnvironment& env, TypeId subTy, TypeId superTy, NotNull<Scope> scope);
SubtypingResult isCovariantWith(SubtypingEnvironment& env, TypePackId subTp, TypePackId superTp, NotNull<Scope> scope);
template<typename SubTy, typename SuperTy>
SubtypingResult isContravariantWith(SubtypingEnvironment& env, SubTy&& subTy, SuperTy&& superTy, NotNull<Scope> scope);
template<typename SubTy, typename SuperTy>
SubtypingResult isInvariantWith(SubtypingEnvironment& env, SubTy&& subTy, SuperTy&& superTy, NotNull<Scope> scope);
template<typename SubTy, typename SuperTy>
SubtypingResult isCovariantWith(SubtypingEnvironment& env, const TryPair<const SubTy*, const SuperTy*>& pair, NotNull<Scope> scope);
template<typename SubTy, typename SuperTy>
SubtypingResult isContravariantWith(SubtypingEnvironment& env, const TryPair<const SubTy*, const SuperTy*>& pair, NotNull<Scope>);
template<typename SubTy, typename SuperTy>
SubtypingResult isInvariantWith(SubtypingEnvironment& env, const TryPair<const SubTy*, const SuperTy*>& pair, NotNull<Scope>);
SubtypingResult isCovariantWith(SubtypingEnvironment& env, TypeId subTy, const UnionType* superUnion, NotNull<Scope> scope);
SubtypingResult isCovariantWith(SubtypingEnvironment& env, const UnionType* subUnion, TypeId superTy, NotNull<Scope> scope);
SubtypingResult isCovariantWith(SubtypingEnvironment& env, TypeId subTy, const IntersectionType* superIntersection, NotNull<Scope> scope);
SubtypingResult isCovariantWith(SubtypingEnvironment& env, const IntersectionType* subIntersection, TypeId superTy, NotNull<Scope> scope);
SubtypingResult isCovariantWith(SubtypingEnvironment& env, const NegationType* subNegation, TypeId superTy, NotNull<Scope> scope);
SubtypingResult isCovariantWith(SubtypingEnvironment& env, const TypeId subTy, const NegationType* superNegation, NotNull<Scope> scope);
SubtypingResult isCovariantWith(SubtypingEnvironment& env, const PrimitiveType* subPrim, const PrimitiveType* superPrim, NotNull<Scope> scope);
SubtypingResult isCovariantWith(
SubtypingEnvironment& env,
const SingletonType* subSingleton,
const PrimitiveType* superPrim,
NotNull<Scope> scope
);
SubtypingResult isCovariantWith(
SubtypingEnvironment& env,
const SingletonType* subSingleton,
const SingletonType* superSingleton,
NotNull<Scope> scope
);
SubtypingResult isCovariantWith(SubtypingEnvironment& env, const TableType* subTable, const TableType* superTable, NotNull<Scope> scope);
SubtypingResult isCovariantWith(SubtypingEnvironment& env, const MetatableType* subMt, const MetatableType* superMt, NotNull<Scope> scope);
SubtypingResult isCovariantWith(SubtypingEnvironment& env, const MetatableType* subMt, const TableType* superTable, NotNull<Scope> scope);
SubtypingResult isCovariantWith(SubtypingEnvironment& env, const ClassType* subClass, const ClassType* superClass, NotNull<Scope> scope);
SubtypingResult
isCovariantWith(SubtypingEnvironment& env, TypeId subTy, const ClassType* subClass, TypeId superTy, const TableType* superTable, NotNull<Scope>);
SubtypingResult isCovariantWith(
SubtypingEnvironment& env,
const FunctionType* subFunction,
const FunctionType* superFunction,
NotNull<Scope> scope
);
SubtypingResult isCovariantWith(SubtypingEnvironment& env, const TableType* subTable, const PrimitiveType* superPrim, NotNull<Scope> scope);
SubtypingResult isCovariantWith(SubtypingEnvironment& env, const PrimitiveType* subPrim, const TableType* superTable, NotNull<Scope> scope);
SubtypingResult isCovariantWith(SubtypingEnvironment& env, const SingletonType* subSingleton, const TableType* superTable, NotNull<Scope> scope);
SubtypingResult isCovariantWith(
SubtypingEnvironment& env,
const TableIndexer& subIndexer,
const TableIndexer& superIndexer,
NotNull<Scope> scope
);
SubtypingResult
isCovariantWith(SubtypingEnvironment& env, const Property& subProperty, const Property& superProperty, const std::string& name, NotNull<Scope>);
SubtypingResult isCovariantWith(
SubtypingEnvironment& env,
const std::shared_ptr<const NormalizedType>& subNorm,
const std::shared_ptr<const NormalizedType>& superNorm,
NotNull<Scope> scope
);
SubtypingResult isCovariantWith(
SubtypingEnvironment& env,
const NormalizedClassType& subClass,
const NormalizedClassType& superClass,
NotNull<Scope> scope
);
SubtypingResult isCovariantWith(SubtypingEnvironment& env, const NormalizedClassType& subClass, const TypeIds& superTables, NotNull<Scope> scope);
SubtypingResult isCovariantWith(
SubtypingEnvironment& env,
const NormalizedStringType& subString,
const NormalizedStringType& superString,
NotNull<Scope> scope
);
SubtypingResult isCovariantWith(
SubtypingEnvironment& env,
const NormalizedStringType& subString,
const TypeIds& superTables,
NotNull<Scope> scope
);
SubtypingResult
isCovariantWith(SubtypingEnvironment& env, const NormalizedFunctionType& subFunction, const NormalizedFunctionType& superFunction, NotNull<Scope>);
SubtypingResult isCovariantWith(SubtypingEnvironment& env, const TypeIds& subTypes, const TypeIds& superTypes, NotNull<Scope> scope);
SubtypingResult isCovariantWith(
SubtypingEnvironment& env,
const VariadicTypePack* subVariadic,
const VariadicTypePack* superVariadic,
NotNull<Scope> scope
);
SubtypingResult isCovariantWith(
SubtypingEnvironment& env,
const TypeFunctionInstanceType* subFunctionInstance,
const TypeId superTy,
NotNull<Scope> scope
);
SubtypingResult isCovariantWith(
SubtypingEnvironment& env,
const TypeId subTy,
const TypeFunctionInstanceType* superFunctionInstance,
NotNull<Scope> scope
);
bool bindGeneric(SubtypingEnvironment& env, TypeId subTp, TypeId superTp);
bool bindGeneric(SubtypingEnvironment& env, TypePackId subTp, TypePackId superTp);
template<typename T, typename Container>
TypeId makeAggregateType(const Container& container, TypeId orElse);
std::pair<TypeId, ErrorVec> handleTypeFunctionReductionResult(const TypeFunctionInstanceType* functionInstance, NotNull<Scope> scope);
[[noreturn]] void unexpected(TypeId ty);
[[noreturn]] void unexpected(TypePackId tp);
};
} // namespace Luau