luau/Analysis/include/Luau/ConstraintGraphBuilder.h
2023-07-28 14:37:00 +03:00

306 lines
13 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/Module.h"
#include "Luau/ModuleResolver.h"
#include "Luau/NotNull.h"
#include "Luau/Refinement.h"
#include "Luau/Symbol.h"
#include "Luau/Type.h"
#include "Luau/TypeUtils.h"
#include "Luau/Variant.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 ConstraintGraphBuilder
{
// 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 CGB is initially constructed.
Scope* rootScope;
// 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 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;
ConstraintGraphBuilder(ModulePtr module, TypeArena* arena, 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);
/**
* 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);
/**
* 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);
void applyRefinements(const ScopePtr& scope, Location location, RefinementId refinement);
/**
* The entry point to the ConstraintGraphBuilder. 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 visit(AstStatBlock* block);
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 = {});
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.
* @return the type of the expression.
*/
Inference check(const ScopePtr& scope, AstExpr* expr, ValueContext context = ValueContext::RValue, std::optional<TypeId> expectedType = {},
bool forceSingleton = false);
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, ValueContext context);
Inference check(const ScopePtr& scope, AstExprGlobal* global);
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);
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);
std::vector<TypeId> checkLValues(const ScopePtr& scope, AstArray<AstExpr*> exprs);
TypeId checkLValue(const ScopePtr& scope, AstExpr* expr);
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.
*
* ConstraintGraphBuilder 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);
/** 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