Sync to upstream/release/532 (#545)

Analysis/include/Luau/Constraint.h

@@ -0,0 +1,82 @@
+// This file is part of the Luau programming language and is licensed under MIT License; see LICENSE.txt for details
+#pragma once
+
+#include "Luau/Location.h"
+#include "Luau/NotNull.h"
+#include "Luau/Variant.h"
+
+#include <memory>
+#include <vector>
+
+namespace Luau
+{
+
+struct Scope2;
+struct TypeVar;
+using TypeId = const TypeVar*;
+
+struct TypePackVar;
+using TypePackId = const TypePackVar*;
+
+// subType <: superType
+struct SubtypeConstraint
+{
+    TypeId subType;
+    TypeId superType;
+};
+
+// subPack <: superPack
+struct PackSubtypeConstraint
+{
+    TypePackId subPack;
+    TypePackId superPack;
+};
+
+// subType ~ gen superType
+struct GeneralizationConstraint
+{
+    TypeId generalizedType;
+    TypeId sourceType;
+    Scope2* scope;
+};
+
+// subType ~ inst superType
+struct InstantiationConstraint
+{
+    TypeId subType;
+    TypeId superType;
+};
+
+using ConstraintV = Variant<SubtypeConstraint, PackSubtypeConstraint, GeneralizationConstraint, InstantiationConstraint>;
+using ConstraintPtr = std::unique_ptr<struct Constraint>;
+
+struct Constraint
+{
+    Constraint(ConstraintV&& c, Location location);
+
+    Constraint(const Constraint&) = delete;
+    Constraint& operator=(const Constraint&) = delete;
+
+    ConstraintV c;
+    Location location;
+    std::vector<NotNull<Constraint>> dependencies;
+};
+
+inline Constraint& asMutable(const Constraint& c)
+{
+    return const_cast<Constraint&>(c);
+}
+
+template<typename T>
+T* getMutable(Constraint& c)
+{
+    return ::Luau::get_if<T>(&c.c);
+}
+
+template<typename T>
+const T* get(const Constraint& c)
+{
+    return getMutable<T>(asMutable(c));
+}
+
+} // namespace Luau

Analysis/include/Luau/ConstraintGraphBuilder.h

@@ -4,79 +4,19 @@
 
 #include <memory>
 #include <vector>
+#include <unordered_map>
 
 #include "Luau/Ast.h"
+#include "Luau/Constraint.h"
 #include "Luau/Module.h"
+#include "Luau/NotNull.h"
 #include "Luau/Symbol.h"
 #include "Luau/TypeVar.h"
 #include "Luau/Variant.h"
 
 namespace Luau
 {
 
-struct Scope2;
-
-// subType <: superType
-struct SubtypeConstraint
-{
-    TypeId subType;
-    TypeId superType;
-};
-
-// subPack <: superPack
-struct PackSubtypeConstraint
-{
-    TypePackId subPack;
-    TypePackId superPack;
-};
-
-// subType ~ gen superType
-struct GeneralizationConstraint
-{
-    TypeId subType;
-    TypeId superType;
-    Scope2* scope;
-};
-
-// subType ~ inst superType
-struct InstantiationConstraint
-{
-    TypeId subType;
-    TypeId superType;
-};
-
-using ConstraintV = Variant<SubtypeConstraint, PackSubtypeConstraint, GeneralizationConstraint, InstantiationConstraint>;
-using ConstraintPtr = std::unique_ptr<struct Constraint>;
-
-struct Constraint
-{
-    Constraint(ConstraintV&& c);
-    Constraint(ConstraintV&& c, std::vector<Constraint*> dependencies);
-
-    Constraint(const Constraint&) = delete;
-    Constraint& operator=(const Constraint&) = delete;
-
-    ConstraintV c;
-    std::vector<Constraint*> dependencies;
-};
-
-inline Constraint& asMutable(const Constraint& c)
-{
-    return const_cast<Constraint&>(c);
-}
-
-template<typename T>
-T* getMutable(Constraint& c)
-{
-    return ::Luau::get_if<T>(&c.c);
-}
-
-template<typename T>
-const T* get(const Constraint& c)
-{
-    return getMutable<T>(asMutable(c));
-}
-
 struct Scope2
 {
     // The parent scope of this scope. Null if there is no parent (i.e. this
@@ -102,6 +42,11 @@ struct ConstraintGraphBuilder
     TypeArena* const arena;
     // The root scope of the module we're generating constraints for.
     Scope2* rootScope;
+    // A mapping of AST node to TypeId.
+    DenseHashMap<const AstExpr*, TypeId> astTypes{nullptr};
+    // A mapping of AST node to TypePackId.
+    DenseHashMap<const AstExpr*, TypePackId> astTypePacks{nullptr};
+    DenseHashMap<const AstExpr*, TypeId> astOriginalCallTypes{nullptr};
 
     explicit ConstraintGraphBuilder(TypeArena* arena);
 
@@ -128,8 +73,9 @@ struct ConstraintGraphBuilder
      * Adds a new constraint with no dependencies to a given scope.
      * @param scope the scope to add the constraint to. Must not be null.
      * @param cv the constraint variant to add.
+     * @param location the location to attribute to the constraint.
      */
-    void addConstraint(Scope2* scope, ConstraintV cv);
+    void addConstraint(Scope2* scope, ConstraintV cv, Location location);
 
     /**
      * Adds a constraint to a given scope.
@@ -148,15 +94,48 @@ struct ConstraintGraphBuilder
     void visit(Scope2* scope, AstStat* stat);
     void visit(Scope2* scope, AstStatBlock* block);
     void visit(Scope2* scope, AstStatLocal* local);
-    void visit(Scope2* scope, AstStatLocalFunction* local);
-    void visit(Scope2* scope, AstStatReturn* local);
+    void visit(Scope2* scope, AstStatLocalFunction* function);
+    void visit(Scope2* scope, AstStatFunction* function);
+    void visit(Scope2* scope, AstStatReturn* ret);
+    void visit(Scope2* scope, AstStatAssign* assign);
+    void visit(Scope2* scope, AstStatIf* ifStatement);
+
+    TypePackId checkExprList(Scope2* scope, const AstArray<AstExpr*>& exprs);
 
     TypePackId checkPack(Scope2* scope, AstArray<AstExpr*> exprs);
     TypePackId checkPack(Scope2* scope, AstExpr* expr);
 
+    /**
+     * 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.
+     * @return the type of the expression.
+     */
     TypeId check(Scope2* scope, AstExpr* expr);
+
+    TypeId checkExprTable(Scope2* scope, AstExprTable* expr);
+    TypeId check(Scope2* scope, AstExprIndexName* indexName);
+
+    std::pair<TypeId, Scope2*> checkFunctionSignature(Scope2* parent, AstExprFunction* fn);
+
+    /**
+     * 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(Scope2* scope, AstExprFunction* fn);
 };
 
-std::vector<const Constraint*> collectConstraints(Scope2* rootScope);
+/**
+ * Collects a vector of borrowed constraints from the scope and all its child
+ * scopes. It is important to only call this function when you're done adding
+ * constraints to the scope or its descendants, lest the borrowed pointers
+ * become invalid due to a container reallocation.
+ * @param rootScope the root scope of the scope graph to collect constraints
+ * from.
+ * @return a list of pointers to constraints contained within the scope graph.
+ * None of these pointers should be null.
+ */
+std::vector<NotNull<Constraint>> collectConstraints(Scope2* rootScope);
 
 } // namespace Luau

Analysis/include/Luau/ConstraintSolver.h

@@ -4,7 +4,8 @@
 
 #include "Luau/Error.h"
 #include "Luau/Variant.h"
-#include "Luau/ConstraintGraphBuilder.h"
+#include "Luau/Constraint.h"
+#include "Luau/ConstraintSolverLogger.h"
 #include "Luau/TypeVar.h"
 
 #include <vector>
@@ -20,85 +21,97 @@ struct ConstraintSolver
 {
     TypeArena* arena;
     InternalErrorReporter iceReporter;
-    // The entire set of constraints that the solver is trying to resolve.
-    std::vector<const Constraint*> constraints;
+    // The entire set of constraints that the solver is trying to resolve. It
+    // is important to not add elements to this vector, lest the underlying
+    // storage that we retain pointers to be mutated underneath us.
+    const std::vector<NotNull<Constraint>> constraints;
     Scope2* rootScope;
-    std::vector<TypeError> errors;
 
     // This includes every constraint that has not been fully solved.
     // A constraint can be both blocked and unsolved, for instance.
-    std::unordered_set<const Constraint*> unsolvedConstraints;
+    std::vector<NotNull<const Constraint>> unsolvedConstraints;
 
     // A mapping of constraint pointer to how many things the constraint is
     // blocked on. Can be empty or 0 for constraints that are not blocked on
     // anything.
-    std::unordered_map<const Constraint*, size_t> blockedConstraints;
+    std::unordered_map<NotNull<const Constraint>, size_t> blockedConstraints;
     // A mapping of type/pack pointers to the constraints they block.
-    std::unordered_map<BlockedConstraintId, std::vector<const Constraint*>> blocked;
+    std::unordered_map<BlockedConstraintId, std::vector<NotNull<const Constraint>>> blocked;
+
+    ConstraintSolverLogger logger;
 
     explicit ConstraintSolver(TypeArena* arena, Scope2* rootScope);
 
     /**
      * Attempts to dispatch all pending constraints and reach a type solution
-     * that satisfies all of the constraints, recording any errors that are
-     * encountered.
+     * that satisfies all of the constraints.
      **/
     void run();
 
     bool done();
 
-    bool tryDispatch(const Constraint* c);
-    bool tryDispatch(const SubtypeConstraint& c);
-    bool tryDispatch(const PackSubtypeConstraint& c);
-    bool tryDispatch(const GeneralizationConstraint& c);
-    bool tryDispatch(const InstantiationConstraint& c, const Constraint* constraint);
+    bool tryDispatch(NotNull<const Constraint> c, bool force);
+    bool tryDispatch(const SubtypeConstraint& c, NotNull<const Constraint> constraint, bool force);
+    bool tryDispatch(const PackSubtypeConstraint& c, NotNull<const Constraint> constraint, bool force);
+    bool tryDispatch(const GeneralizationConstraint& c, NotNull<const Constraint> constraint, bool force);
+    bool tryDispatch(const InstantiationConstraint& c, NotNull<const Constraint> constraint, bool force);
 
+    void block(NotNull<const Constraint> target, NotNull<const Constraint> constraint);
     /**
-     * Marks a constraint as being blocked on a type or type pack. The constraint
-     * solver will not attempt to dispatch blocked constraints until their
-     * dependencies have made progress.
-     * @param target the type or type pack pointer that the constraint is blocked on.
-     * @param constraint the constraint to block.
-     **/
-    void block_(BlockedConstraintId target, const Constraint* constraint);
-    void block(const Constraint* target, const Constraint* constraint);
-    void block(TypeId target, const Constraint* constraint);
-    void block(TypePackId target, const Constraint* constraint);
+     * Block a constraint on the resolution of a TypeVar.
+     * @returns false always.  This is just to allow tryDispatch to return the result of block()
+     */
+    bool block(TypeId target, NotNull<const Constraint> constraint);
+    bool block(TypePackId target, NotNull<const Constraint> constraint);
 
-    /**
-     * Informs the solver that progress has been made on a type or type pack. The
-     * solver will wake up all constraints that are blocked on the type or type pack,
-     * and will resume attempting to dispatch them.
-     * @param progressed the type or type pack pointer that has progressed.
-     **/
-    void unblock_(BlockedConstraintId progressed);
-    void unblock(const Constraint* progressed);
+    void unblock(NotNull<const Constraint> progressed);
     void unblock(TypeId progressed);
     void unblock(TypePackId progressed);
 
+    /**
+     * @returns true if the TypeId is in a blocked state.
+     */
+    bool isBlocked(TypeId ty);
+
     /**
      * Returns whether the constraint is blocked on anything.
      * @param constraint the constraint to check.
      */
-    bool isBlocked(const Constraint* constraint);
-
-    void reportErrors(const std::vector<TypeError>& errors);
+    bool isBlocked(NotNull<const Constraint> constraint);
 
     /**
      * Creates a new Unifier and performs a single unification operation. Commits
-     * the result and reports errors if necessary.
+     * the result.
      * @param subType the sub-type to unify.
      * @param superType the super-type to unify.
      */
-    void unify(TypeId subType, TypeId superType);
+    void unify(TypeId subType, TypeId superType, Location location);
 
     /**
      * Creates a new Unifier and performs a single unification operation. Commits
-     * the result and reports errors if necessary.
+     * the result.
      * @param subPack the sub-type pack to unify.
      * @param superPack the super-type pack to unify.
      */
-    void unify(TypePackId subPack, TypePackId superPack);
+    void unify(TypePackId subPack, TypePackId superPack, Location location);
+
+private:
+    /**
+     * Marks a constraint as being blocked on a type or type pack. The constraint
+     * solver will not attempt to dispatch blocked constraints until their
+     * dependencies have made progress.
+     * @param target the type or type pack pointer that the constraint is blocked on.
+     * @param constraint the constraint to block.
+     **/
+    void block_(BlockedConstraintId target, NotNull<const Constraint> constraint);
+
+    /**
+     * Informs the solver that progress has been made on a type or type pack. The
+     * solver will wake up all constraints that are blocked on the type or type pack,
+     * and will resume attempting to dispatch them.
+     * @param progressed the type or type pack pointer that has progressed.
+     **/
+    void unblock_(BlockedConstraintId progressed);
 };
 
 void dump(Scope2* rootScope, struct ToStringOptions& opts);