luau/Analysis/include/Luau/ConstraintGenerator.h
Vighnesh-V c755875479
Sync to upstream/release/605 ()
- Implemented [Require by String with Relative
Paths](https://github.com/luau-lang/rfcs/blob/master/docs/new-require-by-string-semantics.md)
RFC
- Implemented [Require by String with
Aliases](https://github.com/luau-lang/rfcs/blob/master/docs/require-by-string-aliases.md)
RFC with support for `paths` and `alias` arrays in .luarc
- Added SUBRK and DIVRK bytecode instructions to speed up
constant-number and constant/number operations
- Added `--vector-lib`, `--vector-ctor` and `--vector-type` options to
luau-compile to support code with vectors
 
New Solver
- Correctness fixes to subtyping
- Improvements to dataflow analysis

Native Code Generation
- Added bytecode analysis pass to predict type tags used in operations
- Fixed rare cases of numerical loops being generated without an
interrupt instruction
- Restored optimization data propagation into the linear block
- Duplicate buffer length checks are optimized away

Miscellaneous
- Small performance improvements to new non-strict mode
- Introduced more scripts for fuzzing Luau and processing the results,
including fuzzer build support for CMake

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: David Cope <dcope@roblox.com>
Co-authored-by: Lily Brown <lbrown@roblox.com>
Co-authored-by: Vighnesh Vijay <vvijay@roblox.com>
Co-authored-by: Vyacheslav Egorov <vegorov@roblox.com>

---------

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: David Cope <dcope@roblox.com>
Co-authored-by: Lily Brown <lbrown@roblox.com>
Co-authored-by: Vyacheslav Egorov <vegorov@roblox.com>
2023-12-01 23:46:57 -08:00

358 lines
16 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/Ast.h"
#include "Luau/Constraint.h"
#include "Luau/ControlFlow.h"
#include "Luau/DataFlowGraph.h"
#include "Luau/InsertionOrderedMap.h"
#include "Luau/Module.h"
#include "Luau/ModuleResolver.h"
#include "Luau/Normalize.h"
#include "Luau/NotNull.h"
#include "Luau/Refinement.h"
#include "Luau/Symbol.h"
#include "Luau/TypeFwd.h"
#include "Luau/TypeUtils.h"
#include "Luau/Variant.h"
#include "Luau/Normalize.h"
#include <memory>
#include <vector>
#include <unordered_map>
namespace Luau
{
struct Scope;
using ScopePtr = std::shared_ptr<Scope>;
struct DcrLogger;
struct Inference
{
TypeId ty = nullptr;
RefinementId refinement = nullptr;
Inference() = default;
explicit Inference(TypeId ty, RefinementId refinement = nullptr)
: ty(ty)
, refinement(refinement)
{
}
};
struct InferencePack
{
TypePackId tp = nullptr;
std::vector<RefinementId> refinements;
InferencePack() = default;
explicit InferencePack(TypePackId tp, const std::vector<RefinementId>& refinements = {})
: tp(tp)
, refinements(refinements)
{
}
};
struct ConstraintGenerator
{
// A list of all the scopes in the module. This vector holds ownership of the
// scope pointers; the scopes themselves borrow pointers to other scopes to
// define the scope hierarchy.
std::vector<std::pair<Location, ScopePtr>> scopes;
ModulePtr module;
NotNull<BuiltinTypes> builtinTypes;
const NotNull<TypeArena> arena;
// The root scope of the module we're generating constraints for.
// This is null when the CG is initially constructed.
Scope* rootScope;
struct InferredBinding
{
Scope* scope;
Location location;
TypeIds types;
};
// Some locals have multiple type states. We wish for Scope::bindings to
// map each local name onto the union of every type that the local can have
// over its lifetime, so we use this map to accumulate the set of types it
// might have.
//
// See the functions recordInferredBinding and fillInInferredBindings.
DenseHashMap<Symbol, InferredBinding> inferredBindings{{}};
// Constraints that go straight to the solver.
std::vector<ConstraintPtr> constraints;
// Constraints that do not go to the solver right away. Other constraints
// will enqueue them during solving.
std::vector<ConstraintPtr> unqueuedConstraints;
// The private scope of type aliases for which the type parameters belong to.
DenseHashMap<const AstStatTypeAlias*, ScopePtr> astTypeAliasDefiningScopes{nullptr};
NotNull<const DataFlowGraph> dfg;
RefinementArena refinementArena;
int recursionCount = 0;
// It is pretty uncommon for constraint generation to itself produce errors, but it can happen.
std::vector<TypeError> errors;
// Needed to be able to enable error-suppression preservation for immediate refinements.
NotNull<Normalizer> normalizer;
// Needed to resolve modules to make 'require' import types properly.
NotNull<ModuleResolver> moduleResolver;
// Occasionally constraint generation needs to produce an ICE.
const NotNull<InternalErrorReporter> ice;
ScopePtr globalScope;
std::function<void(const ModuleName&, const ScopePtr&)> prepareModuleScope;
std::vector<RequireCycle> requireCycles;
DcrLogger* logger;
ConstraintGenerator(ModulePtr module, NotNull<Normalizer> normalizer, NotNull<ModuleResolver> moduleResolver,
NotNull<BuiltinTypes> builtinTypes, NotNull<InternalErrorReporter> ice, const ScopePtr& globalScope,
std::function<void(const ModuleName&, const ScopePtr&)> prepareModuleScope, DcrLogger* logger, NotNull<DataFlowGraph> dfg,
std::vector<RequireCycle> requireCycles);
/**
* The entry point to the ConstraintGenerator. This will construct a set
* of scopes, constraints, and free types that can be solved later.
* @param block the root block to generate constraints for.
*/
void visitModuleRoot(AstStatBlock* block);
private:
/**
* Fabricates a new free type belonging to a given scope.
* @param scope the scope the free type belongs to.
*/
TypeId freshType(const ScopePtr& scope);
/**
* Fabricates a new free type pack belonging to a given scope.
* @param scope the scope the free type pack belongs to.
*/
TypePackId freshTypePack(const ScopePtr& scope);
/**
* Fabricates a scope that is a child of another scope.
* @param node the lexical node that the scope belongs to.
* @param parent the parent scope of the new scope. Must not be null.
*/
ScopePtr childScope(AstNode* node, const ScopePtr& parent);
std::optional<TypeId> lookup(Scope* scope, DefId def);
/**
* Adds a new constraint with no dependencies to a given scope.
* @param scope the scope to add the constraint to.
* @param cv the constraint variant to add.
* @return the pointer to the inserted constraint
*/
NotNull<Constraint> addConstraint(const ScopePtr& scope, const Location& location, ConstraintV cv);
/**
* Adds a constraint to a given scope.
* @param scope the scope to add the constraint to. Must not be null.
* @param c the constraint to add.
* @return the pointer to the inserted constraint
*/
NotNull<Constraint> addConstraint(const ScopePtr& scope, std::unique_ptr<Constraint> c);
struct RefinementPartition
{
// Types that we want to intersect against the type of the expression.
std::vector<TypeId> discriminantTypes;
// Sometimes the type we're discriminating against is implicitly nil.
bool shouldAppendNilType = false;
};
using RefinementContext = InsertionOrderedMap<DefId, RefinementPartition>;
void unionRefinements(const RefinementContext& lhs, const RefinementContext& rhs, RefinementContext& dest, std::vector<ConstraintV>* constraints);
void computeRefinement(const ScopePtr& scope, RefinementId refinement, RefinementContext* refis, bool sense, bool eq, std::vector<ConstraintV>* constraints);
void applyRefinements(const ScopePtr& scope, Location location, RefinementId refinement);
ControlFlow visitBlockWithoutChildScope(const ScopePtr& scope, AstStatBlock* block);
ControlFlow visit(const ScopePtr& scope, AstStat* stat);
ControlFlow visit(const ScopePtr& scope, AstStatBlock* block);
ControlFlow visit(const ScopePtr& scope, AstStatLocal* local);
ControlFlow visit(const ScopePtr& scope, AstStatFor* for_);
ControlFlow visit(const ScopePtr& scope, AstStatForIn* forIn);
ControlFlow visit(const ScopePtr& scope, AstStatWhile* while_);
ControlFlow visit(const ScopePtr& scope, AstStatRepeat* repeat);
ControlFlow visit(const ScopePtr& scope, AstStatLocalFunction* function);
ControlFlow visit(const ScopePtr& scope, AstStatFunction* function);
ControlFlow visit(const ScopePtr& scope, AstStatReturn* ret);
ControlFlow visit(const ScopePtr& scope, AstStatAssign* assign);
ControlFlow visit(const ScopePtr& scope, AstStatCompoundAssign* assign);
ControlFlow visit(const ScopePtr& scope, AstStatIf* ifStatement);
ControlFlow visit(const ScopePtr& scope, AstStatTypeAlias* alias);
ControlFlow visit(const ScopePtr& scope, AstStatDeclareGlobal* declareGlobal);
ControlFlow visit(const ScopePtr& scope, AstStatDeclareClass* declareClass);
ControlFlow visit(const ScopePtr& scope, AstStatDeclareFunction* declareFunction);
ControlFlow visit(const ScopePtr& scope, AstStatError* error);
InferencePack checkPack(const ScopePtr& scope, AstArray<AstExpr*> exprs, const std::vector<std::optional<TypeId>>& expectedTypes = {});
InferencePack checkPack(
const ScopePtr& scope, AstExpr* expr, const std::vector<std::optional<TypeId>>& expectedTypes = {}, bool generalize = true);
InferencePack checkPack(const ScopePtr& scope, AstExprCall* call);
/**
* Checks an expression that is expected to evaluate to one type.
* @param scope the scope the expression is contained within.
* @param expr the expression to check.
* @param expectedType the type of the expression that is expected from its
* surrounding context. Used to implement bidirectional type checking.
* @param generalize If true, generalize any lambdas that are encountered.
* @return the type of the expression.
*/
Inference check(
const ScopePtr& scope, AstExpr* expr, std::optional<TypeId> expectedType = {}, bool forceSingleton = false, bool generalize = true);
Inference check(const ScopePtr& scope, AstExprConstantString* string, std::optional<TypeId> expectedType, bool forceSingleton);
Inference check(const ScopePtr& scope, AstExprConstantBool* bool_, std::optional<TypeId> expectedType, bool forceSingleton);
Inference check(const ScopePtr& scope, AstExprLocal* local);
Inference check(const ScopePtr& scope, AstExprGlobal* global);
Inference checkIndexName(const ScopePtr& scope, const RefinementKey* key, AstExpr* indexee, std::string index);
Inference check(const ScopePtr& scope, AstExprIndexName* indexName);
Inference check(const ScopePtr& scope, AstExprIndexExpr* indexExpr);
Inference check(const ScopePtr& scope, AstExprFunction* func, std::optional<TypeId> expectedType, bool generalize);
Inference check(const ScopePtr& scope, AstExprUnary* unary);
Inference check(const ScopePtr& scope, AstExprBinary* binary, std::optional<TypeId> expectedType);
Inference check(const ScopePtr& scope, AstExprIfElse* ifElse, std::optional<TypeId> expectedType);
Inference check(const ScopePtr& scope, AstExprTypeAssertion* typeAssert);
Inference check(const ScopePtr& scope, AstExprInterpString* interpString);
Inference check(const ScopePtr& scope, AstExprTable* expr, std::optional<TypeId> expectedType);
std::tuple<TypeId, TypeId, RefinementId> checkBinary(const ScopePtr& scope, AstExprBinary* binary, std::optional<TypeId> expectedType);
/**
* Generate constraints to assign assignedTy to the expression expr
* @returns the type of the expression. This may or may not be assignedTy itself.
*/
std::optional<TypeId> checkLValue(const ScopePtr& scope, AstExpr* expr, TypeId assignedTy);
std::optional<TypeId> checkLValue(const ScopePtr& scope, AstExprLocal* local, TypeId assignedTy);
std::optional<TypeId> checkLValue(const ScopePtr& scope, AstExprGlobal* global, TypeId assignedTy);
std::optional<TypeId> checkLValue(const ScopePtr& scope, AstExprIndexName* indexName, TypeId assignedTy);
std::optional<TypeId> checkLValue(const ScopePtr& scope, AstExprIndexExpr* indexExpr, TypeId assignedTy);
TypeId updateProperty(const ScopePtr& scope, AstExpr* expr, TypeId assignedTy);
struct FunctionSignature
{
// The type of the function.
TypeId signature;
// The scope that encompasses the function's signature. May be nullptr
// if there was no need for a signature scope (the function has no
// generics).
ScopePtr signatureScope;
// The scope that encompasses the function's body. Is a child scope of
// signatureScope, if present.
ScopePtr bodyScope;
};
FunctionSignature checkFunctionSignature(
const ScopePtr& parent, AstExprFunction* fn, std::optional<TypeId> expectedType = {}, std::optional<Location> originalName = {});
/**
* Checks the body of a function expression.
* @param scope the interior scope of the body of the function.
* @param fn the function expression to check.
*/
void checkFunctionBody(const ScopePtr& scope, AstExprFunction* fn);
/**
* Resolves a type from its AST annotation.
* @param scope the scope that the type annotation appears within.
* @param ty the AST annotation to resolve.
* @param inTypeArguments whether we are resolving a type that's contained within type arguments, `<...>`.
* @return the type of the AST annotation.
**/
TypeId resolveType(const ScopePtr& scope, AstType* ty, bool inTypeArguments, bool replaceErrorWithFresh = false);
/**
* Resolves a type pack from its AST annotation.
* @param scope the scope that the type annotation appears within.
* @param tp the AST annotation to resolve.
* @param inTypeArguments whether we are resolving a type that's contained within type arguments, `<...>`.
* @return the type pack of the AST annotation.
**/
TypePackId resolveTypePack(const ScopePtr& scope, AstTypePack* tp, bool inTypeArguments, bool replaceErrorWithFresh = false);
/**
* Resolves a type pack from its AST annotation.
* @param scope the scope that the type annotation appears within.
* @param list the AST annotation to resolve.
* @param inTypeArguments whether we are resolving a type that's contained within type arguments, `<...>`.
* @return the type pack of the AST annotation.
**/
TypePackId resolveTypePack(const ScopePtr& scope, const AstTypeList& list, bool inTypeArguments, bool replaceErrorWithFresh = false);
/**
* Creates generic types given a list of AST definitions, resolving default
* types as required.
* @param scope the scope that the generics should belong to.
* @param generics the AST generics to create types for.
* @param useCache whether to use the generic type cache for the given
* scope.
* @param addTypes whether to add the types to the scope's
* privateTypeBindings map.
**/
std::vector<std::pair<Name, GenericTypeDefinition>> createGenerics(
const ScopePtr& scope, AstArray<AstGenericType> generics, bool useCache = false, bool addTypes = true);
/**
* Creates generic type packs given a list of AST definitions, resolving
* default type packs as required.
* @param scope the scope that the generic packs should belong to.
* @param generics the AST generics to create type packs for.
* @param useCache whether to use the generic type pack cache for the given
* scope.
* @param addTypes whether to add the types to the scope's
* privateTypePackBindings map.
**/
std::vector<std::pair<Name, GenericTypePackDefinition>> createGenericPacks(
const ScopePtr& scope, AstArray<AstGenericTypePack> packs, bool useCache = false, bool addTypes = true);
Inference flattenPack(const ScopePtr& scope, Location location, InferencePack pack);
void reportError(Location location, TypeErrorData err);
void reportCodeTooComplex(Location location);
/** Scan the program for global definitions.
*
* ConstraintGenerator needs to differentiate between globals and accesses to undefined symbols. Doing this "for
* real" in a general way is going to be pretty hard, so we are choosing not to tackle that yet. For now, we do an
* initial scan of the AST and note what globals are defined.
*/
void prepopulateGlobalScope(const ScopePtr& globalScope, AstStatBlock* program);
// Record the fact that a particular local has a particular type in at least
// one of its states.
void recordInferredBinding(AstLocal* local, TypeId ty);
void fillInInferredBindings(const ScopePtr& globalScope, AstStatBlock* block);
/** Given a function type annotation, return a vector describing the expected types of the calls to the function
* For example, calling a function with annotation ((number) -> string & ((string) -> number))
* yields a vector of size 1, with value: [number | string]
*/
std::vector<std::optional<TypeId>> getExpectedCallTypesForFunctionOverloads(const TypeId fnType);
};
/** Borrow a vector of pointers from a vector of owning pointers to constraints.
*/
std::vector<NotNull<Constraint>> borrowConstraints(const std::vector<ConstraintPtr>& constraints);
} // namespace Luau