Sync to upstream/release/539 (#625)

.gitignore

@@ -8,4 +8,6 @@
 /default.prof*
 /fuzz-*
 /luau
+/luau-tests
+/luau-analyze
 __pycache__

Analysis/include/Luau/ApplyTypeFunction.h

@@ -0,0 +1,32 @@
+// This file is part of the Luau programming language and is licensed under MIT License; see LICENSE.txt for details
+#pragma once
+
+#include "Luau/Substitution.h"
+#include "Luau/TxnLog.h"
+#include "Luau/TypeVar.h"
+
+namespace Luau
+{
+
+// A substitution which replaces the type parameters of a type function by arguments
+struct ApplyTypeFunction : Substitution
+{
+    ApplyTypeFunction(TypeArena* arena)
+        : Substitution(TxnLog::empty(), arena)
+        , encounteredForwardedType(false)
+    {
+    }
+
+    // Never set under deferred constraint resolution.
+    bool encounteredForwardedType;
+    std::unordered_map<TypeId, TypeId> typeArguments;
+    std::unordered_map<TypePackId, TypePackId> typePackArguments;
+    bool ignoreChildren(TypeId ty) override;
+    bool ignoreChildren(TypePackId tp) override;
+    bool isDirty(TypeId ty) override;
+    bool isDirty(TypePackId tp) override;
+    TypeId clean(TypeId ty) override;
+    TypePackId clean(TypePackId tp) override;
+};
+
+} // namespace Luau

Analysis/include/Luau/Constraint.h

@@ -4,6 +4,7 @@
 #include "Luau/Ast.h" // Used for some of the enumerations
 #include "Luau/NotNull.h"
 #include "Luau/Variant.h"
+#include "Luau/TypeVar.h"
 
 #include <string>
 #include <memory>
@@ -71,8 +72,15 @@ struct NameConstraint
     std::string name;
 };
 
+// target ~ inst target
+struct TypeAliasExpansionConstraint
+{
+    // Must be a PendingExpansionTypeVar.
+    TypeId target;
+};
+
 using ConstraintV = Variant<SubtypeConstraint, PackSubtypeConstraint, GeneralizationConstraint, InstantiationConstraint, UnaryConstraint,
-    BinaryConstraint, NameConstraint>;
+    BinaryConstraint, NameConstraint, TypeAliasExpansionConstraint>;
 using ConstraintPtr = std::unique_ptr<struct Constraint>;
 
 struct Constraint

Analysis/include/Luau/ConstraintGraphBuilder.h

@@ -42,6 +42,8 @@ struct ConstraintGraphBuilder
     DenseHashMap<const AstType*, TypeId> astResolvedTypes{nullptr};
     // Type packs resolved from type annotations. Analogous to astTypePacks.
     DenseHashMap<const AstTypePack*, TypePackId> astResolvedTypePacks{nullptr};
+    // Defining scopes for AST nodes.
+    DenseHashMap<const AstStatTypeAlias*, ScopePtr> astTypeAliasDefiningScopes{nullptr};
 
     int recursionCount = 0;
 
@@ -107,6 +109,9 @@ struct ConstraintGraphBuilder
     void visit(const ScopePtr& scope, AstStatAssign* assign);
     void visit(const ScopePtr& scope, AstStatIf* ifStatement);
     void visit(const ScopePtr& scope, AstStatTypeAlias* alias);
+    void visit(const ScopePtr& scope, AstStatDeclareGlobal* declareGlobal);
+    void visit(const ScopePtr& scope, AstStatDeclareClass* declareClass);
+    void visit(const ScopePtr& scope, AstStatDeclareFunction* declareFunction);
 
     TypePackId checkExprList(const ScopePtr& scope, const AstArray<AstExpr*>& exprs);
 
@@ -153,9 +158,10 @@ struct ConstraintGraphBuilder
      * 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 topLevel whether the annotation is a "top-level" annotation.
      * @return the type of the AST annotation.
      **/
-    TypeId resolveType(const ScopePtr& scope, AstType* ty);
+    TypeId resolveType(const ScopePtr& scope, AstType* ty, bool topLevel = false);
 
     /**
      * Resolves a type pack from its AST annotation.

Analysis/include/Luau/ConstraintSolver.h

@@ -17,16 +17,36 @@ namespace Luau
 // never dereference this pointer.
 using BlockedConstraintId = const void*;
 
+struct InstantiationSignature
+{
+    TypeFun fn;
+    std::vector<TypeId> arguments;
+    std::vector<TypePackId> packArguments;
+
+    bool operator==(const InstantiationSignature& rhs) const;
+    bool operator!=(const InstantiationSignature& rhs) const
+    {
+        return !((*this) == rhs);
+    }
+};
+
+struct HashInstantiationSignature
+{
+    size_t operator()(const InstantiationSignature& signature) const;
+};
+
 struct ConstraintSolver
 {
     TypeArena* arena;
     InternalErrorReporter iceReporter;
-    // 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;
+    // The entire set of constraints that the solver is trying to resolve.
+    std::vector<NotNull<Constraint>> constraints;
     NotNull<Scope> rootScope;
 
+    // Constraints that the solver has generated, rather than sourcing from the
+    // scope tree.
+    std::vector<std::unique_ptr<Constraint>> solverConstraints;
+
     // This includes every constraint that has not been fully solved.
     // A constraint can be both blocked and unsolved, for instance.
     std::vector<NotNull<const Constraint>> unsolvedConstraints;
@@ -37,6 +57,8 @@ struct ConstraintSolver
     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<NotNull<const Constraint>>> blocked;
+    // Memoized instantiations of type aliases.
+    DenseHashMap<InstantiationSignature, TypeId, HashInstantiationSignature> instantiatedAliases{{}};
 
     ConstraintSolverLogger logger;
 
@@ -62,6 +84,7 @@ struct ConstraintSolver
     bool tryDispatch(const UnaryConstraint& c, NotNull<const Constraint> constraint, bool force);
     bool tryDispatch(const BinaryConstraint& c, NotNull<const Constraint> constraint, bool force);
     bool tryDispatch(const NameConstraint& c, NotNull<const Constraint> constraint);
+    bool tryDispatch(const TypeAliasExpansionConstraint& c, NotNull<const Constraint> constraint);
 
     void block(NotNull<const Constraint> target, NotNull<const Constraint> constraint);
     /**
@@ -102,6 +125,11 @@ struct ConstraintSolver
      */
     void unify(TypePackId subPack, TypePackId superPack);
 
+    /** Pushes a new solver constraint to the solver.
+     * @param cv the body of the constraint.
+     **/
+    void pushConstraint(ConstraintV cv);
+
 private:
     /**
      * Marks a constraint as being blocked on a type or type pack. The constraint

Analysis/include/Luau/Frontend.h

@@ -152,6 +152,8 @@ struct Frontend
     void registerBuiltinDefinition(const std::string& name, std::function<void(TypeChecker&, ScopePtr)>);
     void applyBuiltinDefinitionToEnvironment(const std::string& environmentName, const std::string& definitionName);
 
+    LoadDefinitionFileResult loadDefinitionFile(std::string_view source, const std::string& packageName);
+
     NotNull<Scope> getGlobalScope();
 
 private:
@@ -169,7 +171,7 @@ private:
     std::unordered_map<std::string, ScopePtr> environments;
     std::unordered_map<std::string, std::function<void(TypeChecker&, ScopePtr)>> builtinDefinitions;
 
-    std::unique_ptr<Scope> globalScope;
+    ScopePtr globalScope;
 
 public:
     FileResolver* fileResolver;
@@ -180,6 +182,7 @@ public:
     ConfigResolver* configResolver;
     FrontendOptions options;
     InternalErrorReporter iceHandler;
+    TypeArena globalTypes;
     TypeArena arenaForAutocomplete;
 
     std::unordered_map<ModuleName, SourceNode> sourceNodes;

Analysis/include/Luau/JsonEmitter.h

@@ -0,0 +1,235 @@
+// This file is part of the Luau programming language and is licensed under MIT License; see LICENSE.txt for details
+#pragma once
+
+#include <type_traits>
+#include <string>
+#include <optional>
+#include <vector>
+
+#include "Luau/NotNull.h"
+
+namespace Luau::Json
+{
+
+struct JsonEmitter;
+
+/// Writes a value to the JsonEmitter. Note that this can produce invalid JSON
+/// if you do not insert commas or appropriate object / array syntax.
+template<typename T>
+void write(JsonEmitter&, T) = delete;
+
+/// Writes a boolean to a JsonEmitter.
+/// @param emitter the emitter to write to.
+/// @param b the boolean to write.
+void write(JsonEmitter& emitter, bool b);
+
+/// Writes an integer to a JsonEmitter.
+/// @param emitter the emitter to write to.
+/// @param i the integer to write.
+void write(JsonEmitter& emitter, int i);
+
+/// Writes an integer to a JsonEmitter.
+/// @param emitter the emitter to write to.
+/// @param i the integer to write.
+void write(JsonEmitter& emitter, long i);
+
+/// Writes an integer to a JsonEmitter.
+/// @param emitter the emitter to write to.
+/// @param i the integer to write.
+void write(JsonEmitter& emitter, long long i);
+
+/// Writes an integer to a JsonEmitter.
+/// @param emitter the emitter to write to.
+/// @param i the integer to write.
+void write(JsonEmitter& emitter, unsigned int i);
+
+/// Writes an integer to a JsonEmitter.
+/// @param emitter the emitter to write to.
+/// @param i the integer to write.
+void write(JsonEmitter& emitter, unsigned long i);
+
+/// Writes an integer to a JsonEmitter.
+/// @param emitter the emitter to write to.
+/// @param i the integer to write.
+void write(JsonEmitter& emitter, unsigned long long i);
+
+/// Writes a double to a JsonEmitter.
+/// @param emitter the emitter to write to.
+/// @param d the double to write.
+void write(JsonEmitter& emitter, double d);
+
+/// Writes a string to a JsonEmitter. The string will be escaped.
+/// @param emitter the emitter to write to.
+/// @param sv the string to write.
+void write(JsonEmitter& emitter, std::string_view sv);
+
+/// Writes a character to a JsonEmitter as a single-character string. The
+/// character will be escaped.
+/// @param emitter the emitter to write to.
+/// @param c the string to write.
+void write(JsonEmitter& emitter, char c);
+
+/// Writes a string to a JsonEmitter. The string will be escaped.
+/// @param emitter the emitter to write to.
+/// @param str the string to write.
+void write(JsonEmitter& emitter, const char* str);
+
+/// Writes a string to a JsonEmitter. The string will be escaped.
+/// @param emitter the emitter to write to.
+/// @param str the string to write.
+void write(JsonEmitter& emitter, const std::string& str);
+
+/// Writes null to a JsonEmitter.
+/// @param emitter the emitter to write to.
+void write(JsonEmitter& emitter, std::nullptr_t);
+
+/// Writes null to a JsonEmitter.
+/// @param emitter the emitter to write to.
+void write(JsonEmitter& emitter, std::nullopt_t);
+
+struct ObjectEmitter;
+struct ArrayEmitter;
+
+struct JsonEmitter
+{
+    JsonEmitter();
+
+    /// Converts the current contents of the JsonEmitter to a string value. This
+    /// does not invalidate the emitter, but it does not clear it either.
+    std::string str();
+
+    /// Returns the current comma state and resets it to false. Use popComma to
+    /// restore the old state.
+    /// @returns the previous comma state.
+    bool pushComma();
+
+    /// Restores a previous comma state.
+    /// @param c the comma state to restore.
+    void popComma(bool c);
+
+    /// Writes a raw sequence of characters to the buffer, without escaping or
+    /// other processing.
+    /// @param sv the character sequence to write.
+    void writeRaw(std::string_view sv);
+
+    /// Writes a character to the buffer, without escaping or other processing.
+    /// @param c the character to write.
+    void writeRaw(char c);
+
+    /// Writes a comma if this wasn't the first time writeComma has been
+    /// invoked. Otherwise, sets the comma state to true.
+    /// @see pushComma
+    /// @see popComma
+    void writeComma();
+
+    /// Begins writing an object to the emitter.
+    /// @returns an ObjectEmitter that can be used to write key-value pairs.
+    ObjectEmitter writeObject();
+
+    /// Begins writing an array to the emitter.
+    /// @returns an ArrayEmitter that can be used to write values.
+    ArrayEmitter writeArray();
+
+private:
+    bool comma = false;
+    std::vector<std::string> chunks;
+
+    void newChunk();
+};
+
+/// An interface for writing an object into a JsonEmitter instance.
+/// @see JsonEmitter::writeObject
+struct ObjectEmitter
+{
+    ObjectEmitter(NotNull<JsonEmitter> emitter);
+    ~ObjectEmitter();
+
+    NotNull<JsonEmitter> emitter;
+    bool comma;
+    bool finished;
+
+    /// Writes a key-value pair to the associated JsonEmitter. Keys will be escaped.
+    /// @param name the name of the key-value pair.
+    /// @param value the value to write.
+    template<typename T>
+    void writePair(std::string_view name, T value)
+    {
+        if (finished)
+        {
+            return;
+        }
+
+        emitter->writeComma();
+        write(*emitter, name);
+        emitter->writeRaw(':');
+        write(*emitter, value);
+    }
+
+    /// Finishes writing the object, appending a closing `}` character and
+    /// resetting the comma state of the associated emitter. This can only be
+    /// called once, and once called will render the emitter unusable. This
+    /// method is also called when the ObjectEmitter is destructed.
+    void finish();
+};
+
+/// An interface for writing an array into a JsonEmitter instance. Array values
+/// do not need to be the same type.
+/// @see JsonEmitter::writeArray
+struct ArrayEmitter
+{
+    ArrayEmitter(NotNull<JsonEmitter> emitter);
+    ~ArrayEmitter();
+
+    NotNull<JsonEmitter> emitter;
+    bool comma;
+    bool finished;
+
+    /// Writes a value to the array.
+    /// @param value the value to write.
+    template<typename T>
+    void writeValue(T value)
+    {
+        if (finished)
+        {
+            return;
+        }
+
+        emitter->writeComma();
+        write(*emitter, value);
+    }
+
+    /// Finishes writing the object, appending a closing `]` character and
+    /// resetting the comma state of the associated emitter. This can only be
+    /// called once, and once called will render the emitter unusable. This
+    /// method is also called when the ArrayEmitter is destructed.
+    void finish();
+};
+
+/// Writes a vector as an array to a JsonEmitter.
+/// @param emitter the emitter to write to.
+/// @param vec the vector to write.
+template<typename T>
+void write(JsonEmitter& emitter, const std::vector<T>& vec)
+{
+    ArrayEmitter a = emitter.writeArray();
+
+    for (const T& value : vec)
+        a.writeValue(value);
+
+    a.finish();
+}
+
+/// Writes an optional to a JsonEmitter. Will write the contained value, if
+/// present, or null, if no value is present.
+/// @param emitter the emitter to write to.
+/// @param v the value to write.
+template<typename T>
+void write(JsonEmitter& emitter, const std::optional<T>& v)
+{
+    if (v.has_value())
+        write(emitter, *v);
+    else
+        emitter.writeRaw("null");
+}
+
+} // namespace Luau::Json

Analysis/include/Luau/Linter.h

@@ -52,6 +52,7 @@ struct LintWarning
         Code_DuplicateCondition = 24,
         Code_MisleadingAndOr = 25,
         Code_CommentDirective = 26,
+        Code_IntegerParsing = 27,
 
         Code__Count
     };

Analysis/include/Luau/Module.h

@@ -68,7 +68,7 @@ struct Module
     std::shared_ptr<Allocator> allocator;
     std::shared_ptr<AstNameTable> names;
 
-    std::vector<std::pair<Location, ScopePtr>> scopes;                 // never empty
+    std::vector<std::pair<Location, ScopePtr>> scopes; // never empty
 
     DenseHashMap<const AstExpr*, TypeId> astTypes{nullptr};
     DenseHashMap<const AstExpr*, TypePackId> astTypePacks{nullptr};

Analysis/include/Luau/Scope.h

@@ -36,7 +36,7 @@ struct Scope
     // All the children of this scope.
     std::vector<NotNull<Scope>> children;
     std::unordered_map<Symbol, Binding> bindings;
-    std::unordered_map<Name, TypeId> typeBindings;
+    std::unordered_map<Name, TypeFun> typeBindings;
     std::unordered_map<Name, TypePackId> typePackBindings;
     TypePackId returnType;
     std::optional<TypePackId> varargPack;
@@ -52,7 +52,7 @@ struct Scope
     std::unordered_map<Name, std::unordered_map<Name, TypeFun>> importedTypeBindings;
 
     std::optional<TypeId> lookup(Symbol sym);
-    std::optional<TypeId> lookupTypeBinding(const Name& name);
+    std::optional<TypeFun> lookupTypeBinding(const Name& name);
     std::optional<TypePackId> lookupTypePackBinding(const Name& name);
 
     std::optional<TypeFun> lookupType(const Name& name);

Analysis/include/Luau/Substitution.h

@@ -139,6 +139,8 @@ struct FindDirty : Tarjan
 {
     std::vector<bool> dirty;
 
+    void clearTarjan();
+
     // Get/set the dirty bit for an index (grows the vector if needed)
     bool getDirty(int index);
     void setDirty(int index, bool d);
@@ -176,6 +178,8 @@ public:
     TypeArena* arena;
     DenseHashMap<TypeId, TypeId> newTypes{nullptr};
     DenseHashMap<TypePackId, TypePackId> newPacks{nullptr};
+    DenseHashSet<TypeId> replacedTypes{nullptr};
+    DenseHashSet<TypePackId> replacedTypePacks{nullptr};
 
     std::optional<TypeId> substitute(TypeId ty);
     std::optional<TypePackId> substitute(TypePackId tp);

Analysis/include/Luau/TypeInfer.h

@@ -65,28 +65,6 @@ struct Anyification : Substitution
     }
 };
 
-// A substitution which replaces the type parameters of a type function by arguments
-struct ApplyTypeFunction : Substitution
-{
-    ApplyTypeFunction(TypeArena* arena, TypeLevel level)
-        : Substitution(TxnLog::empty(), arena)
-        , level(level)
-        , encounteredForwardedType(false)
-    {
-    }
-
-    TypeLevel level;
-    bool encounteredForwardedType;
-    std::unordered_map<TypeId, TypeId> typeArguments;
-    std::unordered_map<TypePackId, TypePackId> typePackArguments;
-    bool ignoreChildren(TypeId ty) override;
-    bool ignoreChildren(TypePackId tp) override;
-    bool isDirty(TypeId ty) override;
-    bool isDirty(TypePackId tp) override;
-    TypeId clean(TypeId ty) override;
-    TypePackId clean(TypePackId tp) override;
-};
-
 struct GenericTypeDefinitions
 {
     std::vector<GenericTypeDefinition> genericTypes;

Analysis/include/Luau/TypeVar.h

@@ -223,12 +223,16 @@ struct GenericTypeDefinition
 {
     TypeId ty;
     std::optional<TypeId> defaultValue;
+
+    bool operator==(const GenericTypeDefinition& rhs) const;
 };
 
 struct GenericTypePackDefinition
 {
     TypePackId tp;
     std::optional<TypePackId> defaultValue;
+
+    bool operator==(const GenericTypePackDefinition& rhs) const;
 };
 
 struct FunctionArgument
@@ -426,6 +430,12 @@ struct TypeFun
     TypeId type;
 
     TypeFun() = default;
+
+    explicit TypeFun(TypeId ty)
+        : type(ty)
+    {
+    }
+
     TypeFun(std::vector<GenericTypeDefinition> typeParams, TypeId type)
         : typeParams(std::move(typeParams))
         , type(type)
@@ -438,6 +448,27 @@ struct TypeFun
         , type(type)
     {
     }
+
+    bool operator==(const TypeFun& rhs) const;
+};
+
+/** Represents a pending type alias instantiation.
+ *
+ * In order to afford (co)recursive type aliases, we need to reason about a
+ * partially-complete instantiation. This requires encoding more information in
+ * a type variable than a BlockedTypeVar affords, hence this. Each
+ * PendingExpansionTypeVar has a corresponding TypeAliasExpansionConstraint
+ * enqueued in the solver to convert it to an actual instantiated type
+ */
+struct PendingExpansionTypeVar
+{
+    PendingExpansionTypeVar(TypeFun fn, std::vector<TypeId> typeArguments, std::vector<TypePackId> packArguments);
+    TypeFun fn;
+    std::vector<TypeId> typeArguments;
+    std::vector<TypePackId> packArguments;
+    size_t index;
+
+    static size_t nextIndex;
 };
 
 // Anything!  All static checking is off.
@@ -470,8 +501,10 @@ struct NeverTypeVar
 
 using ErrorTypeVar = Unifiable::Error;
 
-using TypeVariant = Unifiable::Variant<TypeId, PrimitiveTypeVar, ConstrainedTypeVar, BlockedTypeVar, SingletonTypeVar, FunctionTypeVar, TableTypeVar,
-    MetatableTypeVar, ClassTypeVar, AnyTypeVar, UnionTypeVar, IntersectionTypeVar, LazyTypeVar, UnknownTypeVar, NeverTypeVar>;
+using TypeVariant =
+    Unifiable::Variant<TypeId, PrimitiveTypeVar, ConstrainedTypeVar, BlockedTypeVar, PendingExpansionTypeVar, SingletonTypeVar, FunctionTypeVar,
+        TableTypeVar, MetatableTypeVar, ClassTypeVar, AnyTypeVar, UnionTypeVar, IntersectionTypeVar, LazyTypeVar, UnknownTypeVar, NeverTypeVar>;
+
 
 struct TypeVar final
 {

Analysis/include/Luau/VisitTypeVar.h

@@ -9,7 +9,6 @@
 #include "Luau/TypeVar.h"
 
 LUAU_FASTINT(LuauVisitRecursionLimit)
-LUAU_FASTFLAG(LuauNormalizeFlagIsConservative)
 LUAU_FASTFLAG(LuauCompleteVisitor);
 
 namespace Luau
@@ -150,6 +149,10 @@ struct GenericTypeVarVisitor
     {
         return visit(ty);
     }
+    virtual bool visit(TypeId ty, const PendingExpansionTypeVar& petv)
+    {
+        return visit(ty);
+    }
     virtual bool visit(TypeId ty, const SingletonTypeVar& stv)
     {
         return visit(ty);
@@ -285,8 +288,6 @@ struct GenericTypeVarVisitor
                     traverse(partTy);
             }
         }
-        else if (!FFlag::LuauCompleteVisitor)
-            return visit_detail::unsee(seen, ty);
         else if (get<LazyTypeVar>(ty))
         {
             // Visiting into LazyTypeVar may necessarily cause infinite expansion, so we don't do that on purpose.
@@ -301,6 +302,37 @@ struct GenericTypeVarVisitor
             visit(ty, *utv);
         else if (auto ntv = get<NeverTypeVar>(ty))
             visit(ty, *ntv);
+        else if (auto petv = get<PendingExpansionTypeVar>(ty))
+        {
+            if (visit(ty, *petv))
+            {
+                traverse(petv->fn.type);
+
+                for (const GenericTypeDefinition& p : petv->fn.typeParams)
+                {
+                    traverse(p.ty);
+
+                    if (p.defaultValue)
+                        traverse(*p.defaultValue);
+                }
+
+                for (const GenericTypePackDefinition& p : petv->fn.typePackParams)
+                {
+                    traverse(p.tp);
+
+                    if (p.defaultValue)
+                        traverse(*p.defaultValue);
+                }
+
+                for (TypeId a : petv->typeArguments)
+                    traverse(a);
+
+                for (TypePackId a : petv->packArguments)
+                    traverse(a);
+            }
+        }
+        else if (!FFlag::LuauCompleteVisitor)
+            return visit_detail::unsee(seen, ty);
         else
             LUAU_ASSERT(!"GenericTypeVarVisitor::traverse(TypeId) is not exhaustive!");
 
@@ -333,7 +365,7 @@ struct GenericTypeVarVisitor
         else if (auto pack = get<TypePack>(tp))
         {
             bool res = visit(tp, *pack);
-            if (!FFlag::LuauNormalizeFlagIsConservative || res)
+            if (res)
             {
                 for (TypeId ty : pack->head)
                     traverse(ty);
@@ -345,7 +377,7 @@ struct GenericTypeVarVisitor
         else if (auto pack = get<VariadicTypePack>(tp))
         {
             bool res = visit(tp, *pack);
-            if (!FFlag::LuauNormalizeFlagIsConservative || res)
+            if (res)
                 traverse(pack->ty);
         }
         else

Analysis/src/ApplyTypeFunction.cpp

@@ -0,0 +1,60 @@
+// This file is part of the Luau programming language and is licensed under MIT License; see LICENSE.txt for details
+
+#include "Luau/ApplyTypeFunction.h"
+
+namespace Luau
+{
+
+bool ApplyTypeFunction::isDirty(TypeId ty)
+{
+    if (typeArguments.count(ty))
+        return true;
+    else if (const FreeTypeVar* ftv = get<FreeTypeVar>(ty))
+    {
+        if (ftv->forwardedTypeAlias)
+            encounteredForwardedType = true;
+        return false;
+    }
+    else
+        return false;
+}
+
+bool ApplyTypeFunction::isDirty(TypePackId tp)
+{
+    if (typePackArguments.count(tp))
+        return true;
+    else
+        return false;
+}
+
+bool ApplyTypeFunction::ignoreChildren(TypeId ty)
+{
+    if (get<GenericTypeVar>(ty))
+        return true;
+    else
+        return false;
+}
+
+bool ApplyTypeFunction::ignoreChildren(TypePackId tp)
+{
+    if (get<GenericTypePack>(tp))
+        return true;
+    else
+        return false;
+}
+
+TypeId ApplyTypeFunction::clean(TypeId ty)
+{
+    TypeId& arg = typeArguments[ty];
+    LUAU_ASSERT(arg);
+    return arg;
+}
+
+TypePackId ApplyTypeFunction::clean(TypePackId tp)
+{
+    TypePackId& arg = typePackArguments[tp];
+    LUAU_ASSERT(arg);
+    return arg;
+}
+
+} // namespace Luau

Analysis/src/AstJsonEncoder.cpp

@@ -1,5 +1,5 @@
 // This file is part of the Luau programming language and is licensed under MIT License; see LICENSE.txt for details
-#include "Luau/JsonEncoder.h"
+#include "Luau/AstJsonEncoder.h"
 
 #include "Luau/Ast.h"
 #include "Luau/ParseResult.h"
@@ -773,7 +773,7 @@ struct AstJsonEncoder : public AstVisitor
             PROP(indexer);
         });
     }
-    
+
     void write(struct AstTableIndexer* indexer)
     {
         if (indexer)
@@ -1178,7 +1178,6 @@ struct AstJsonEncoder : public AstVisitor
             write("location", comment.location);
             popComma(c);
             writeRaw("}");
-            
         }
     }
 };

Analysis/src/AstQuery.cpp

@@ -314,7 +314,7 @@ std::optional<Binding> findBindingAtPosition(const Module& module, const SourceM
         auto iter = currentScope->bindings.find(name);
         if (iter != currentScope->bindings.end() && iter->second.location.begin <= pos)
         {
-            /* Ignore this binding if we're inside its definition. e.g. local abc = abc -- Will take the definition of abc from outer scope */
+            // Ignore this binding if we're inside its definition. e.g. local abc = abc -- Will take the definition of abc from outer scope
             std::optional<AstStatLocal*> bindingStatement = findBindingLocalStatement(source, iter->second);
             if (!bindingStatement || !(*bindingStatement)->location.contains(pos))
                 return iter->second;

Analysis/src/BuiltinDefinitions.cpp

@@ -10,6 +10,7 @@
 
 LUAU_FASTFLAGVARIABLE(LuauSetMetaTableArgsCheck, false)
 LUAU_FASTFLAG(LuauUnknownAndNeverType)
+LUAU_FASTFLAGVARIABLE(LuauBuiltInMetatableNoBadSynthetic, false)
 
 /** FIXME: Many of these type definitions are not quite completely accurate.
  *
@@ -349,7 +350,7 @@ static std::optional<WithPredicate<TypePackId>> magicFunctionSetMetaTable(
 
                 if (tableName == metatableName)
                     mtv.syntheticName = tableName;
-                else
+                else if (!FFlag::LuauBuiltInMetatableNoBadSynthetic)
                     mtv.syntheticName = "{ @metatable: " + metatableName + ", " + tableName + " }";
             }
 

Analysis/src/Clone.cpp

@@ -48,6 +48,7 @@ struct TypeCloner
     void operator()(const Unifiable::Bound<TypeId>& t);
     void operator()(const Unifiable::Error& t);
     void operator()(const BlockedTypeVar& t);
+    void operator()(const PendingExpansionTypeVar& t);
     void operator()(const PrimitiveTypeVar& t);
     void operator()(const ConstrainedTypeVar& t);
     void operator()(const SingletonTypeVar& t);
@@ -166,6 +167,52 @@ void TypeCloner::operator()(const BlockedTypeVar& t)
     defaultClone(t);
 }
 
+void TypeCloner::operator()(const PendingExpansionTypeVar& t)
+{
+    TypeId res = dest.addType(PendingExpansionTypeVar{t.fn, t.typeArguments, t.packArguments});
+    PendingExpansionTypeVar* petv = getMutable<PendingExpansionTypeVar>(res);
+    LUAU_ASSERT(petv);
+
+    seenTypes[typeId] = res;
+
+    std::vector<TypeId> typeArguments;
+    for (TypeId arg : t.typeArguments)
+        typeArguments.push_back(clone(arg, dest, cloneState));
+
+    std::vector<TypePackId> packArguments;
+    for (TypePackId arg : t.packArguments)
+        packArguments.push_back(clone(arg, dest, cloneState));
+
+    TypeFun fn;
+    fn.type = clone(t.fn.type, dest, cloneState);
+
+    for (const GenericTypeDefinition& param : t.fn.typeParams)
+    {
+        TypeId ty = clone(param.ty, dest, cloneState);
+        std::optional<TypeId> defaultValue = param.defaultValue;
+
+        if (defaultValue)
+            defaultValue = clone(*defaultValue, dest, cloneState);
+
+        fn.typeParams.push_back(GenericTypeDefinition{ty, defaultValue});
+    }
+
+    for (const GenericTypePackDefinition& param : t.fn.typePackParams)
+    {
+        TypePackId tp = clone(param.tp, dest, cloneState);
+        std::optional<TypePackId> defaultValue = param.defaultValue;
+
+        if (defaultValue)
+            defaultValue = clone(*defaultValue, dest, cloneState);
+
+        fn.typePackParams.push_back(GenericTypePackDefinition{tp, defaultValue});
+    }
+
+    petv->fn = std::move(fn);
+    petv->typeArguments = std::move(typeArguments);
+    petv->packArguments = std::move(packArguments);
+}
+
 void TypeCloner::operator()(const PrimitiveTypeVar& t)
 {
     defaultClone(t);
@@ -452,6 +499,11 @@ TypeId shallowClone(TypeId ty, TypeArena& dest, const TxnLog* log)
         ConstrainedTypeVar clone{ctv->level, ctv->parts};
         result = dest.addType(std::move(clone));
     }
+    else if (const PendingExpansionTypeVar* petv = get<PendingExpansionTypeVar>(ty))
+    {
+        PendingExpansionTypeVar clone{petv->fn, petv->typeArguments, petv->packArguments};
+        result = dest.addType(std::move(clone));
+    }
     else
         return result;
 

Analysis/src/ConstraintGraphBuilder.cpp

@@ -70,11 +70,11 @@ void ConstraintGraphBuilder::visit(AstStatBlock* block)
     prepopulateGlobalScope(scope, block);
 
     // TODO: We should share the global scope.
-    rootScope->typeBindings["nil"] = singletonTypes.nilType;
-    rootScope->typeBindings["number"] = singletonTypes.numberType;
-    rootScope->typeBindings["string"] = singletonTypes.stringType;
-    rootScope->typeBindings["boolean"] = singletonTypes.booleanType;
-    rootScope->typeBindings["thread"] = singletonTypes.threadType;
+    rootScope->typeBindings["nil"] = TypeFun{singletonTypes.nilType};
+    rootScope->typeBindings["number"] = TypeFun{singletonTypes.numberType};
+    rootScope->typeBindings["string"] = TypeFun{singletonTypes.stringType};
+    rootScope->typeBindings["boolean"] = TypeFun{singletonTypes.booleanType};
+    rootScope->typeBindings["thread"] = TypeFun{singletonTypes.threadType};
 
     visitBlockWithoutChildScope(scope, block);
 }
@@ -89,6 +89,53 @@ void ConstraintGraphBuilder::visitBlockWithoutChildScope(const ScopePtr& scope,
         return;
     }
 
+    std::unordered_map<Name, Location> aliasDefinitionLocations;
+
+    // In order to enable mutually-recursive type aliases, we need to
+    // populate the type bindings before we actually check any of the
+    // alias statements. Since we're not ready to actually resolve
+    // any of the annotations, we just use a fresh type for now.
+    for (AstStat* stat : block->body)
+    {
+        if (auto alias = stat->as<AstStatTypeAlias>())
+        {
+            if (scope->typeBindings.count(alias->name.value) != 0)
+            {
+                auto it = aliasDefinitionLocations.find(alias->name.value);
+                LUAU_ASSERT(it != aliasDefinitionLocations.end());
+                reportError(alias->location, DuplicateTypeDefinition{alias->name.value, it->second});
+                continue;
+            }
+
+            bool hasGenerics = alias->generics.size > 0 || alias->genericPacks.size > 0;
+
+            ScopePtr defnScope = scope;
+            if (hasGenerics)
+            {
+                defnScope = childScope(alias->location, scope);
+            }
+
+            TypeId initialType = freshType(scope);
+            TypeFun initialFun = TypeFun{initialType};
+
+            for (const auto& [name, gen] : createGenerics(defnScope, alias->generics))
+            {
+                initialFun.typeParams.push_back(gen);
+                defnScope->typeBindings[name] = TypeFun{gen.ty};
+            }
+
+            for (const auto& [name, genPack] : createGenericPacks(defnScope, alias->genericPacks))
+            {
+                initialFun.typePackParams.push_back(genPack);
+                defnScope->typePackBindings[name] = genPack.tp;
+            }
+
+            scope->typeBindings[alias->name.value] = std::move(initialFun);
+            astTypeAliasDefiningScopes[alias] = defnScope;
+            aliasDefinitionLocations[alias->name.value] = alias->location;
+        }
+    }
+
     for (AstStat* stat : block->body)
         visit(scope, stat);
 }
@@ -117,6 +164,12 @@ void ConstraintGraphBuilder::visit(const ScopePtr& scope, AstStat* stat)
         visit(scope, i);
     else if (auto a = stat->as<AstStatTypeAlias>())
         visit(scope, a);
+    else if (auto s = stat->as<AstStatDeclareGlobal>())
+        visit(scope, s);
+    else if (auto s = stat->as<AstStatDeclareClass>())
+        visit(scope, s);
+    else if (auto s = stat->as<AstStatDeclareFunction>())
+        visit(scope, s);
     else
         LUAU_ASSERT(0);
 }
@@ -133,7 +186,7 @@ void ConstraintGraphBuilder::visit(const ScopePtr& scope, AstStatLocal* local)
         if (local->annotation)
         {
             location = local->annotation->location;
-            TypeId annotation = resolveType(scope, local->annotation);
+            TypeId annotation = resolveType(scope, local->annotation, /* topLevel */ true);
             addConstraint(scope, SubtypeConstraint{ty, annotation});
         }
 
@@ -171,11 +224,10 @@ void ConstraintGraphBuilder::visit(const ScopePtr& scope, AstStatLocal* local)
 
 void ConstraintGraphBuilder::visit(const ScopePtr& scope, AstStatFor* for_)
 {
-    auto checkNumber = [&](AstExpr* expr)
-    {
+    auto checkNumber = [&](AstExpr* expr) {
         if (!expr)
             return;
-        
+
         TypeId t = check(scope, expr);
         addConstraint(scope, SubtypeConstraint{t, singletonTypes.numberType});
     };
@@ -307,19 +359,6 @@ void ConstraintGraphBuilder::visit(const ScopePtr& scope, AstStatBlock* block)
 {
     ScopePtr innerScope = childScope(block->location, scope);
 
-    // In order to enable mutually-recursive type aliases, we need to
-    // populate the type bindings before we actually check any of the
-    // alias statements. Since we're not ready to actually resolve
-    // any of the annotations, we just use a fresh type for now.
-    for (AstStat* stat : block->body)
-    {
-        if (auto alias = stat->as<AstStatTypeAlias>())
-        {
-            TypeId initialType = freshType(scope);
-            scope->typeBindings[alias->name.value] = initialType;
-        }
-    }
-
     visitBlockWithoutChildScope(innerScope, block);
 }
 
@@ -348,29 +387,48 @@ void ConstraintGraphBuilder::visit(const ScopePtr& scope, AstStatIf* ifStatement
 void ConstraintGraphBuilder::visit(const ScopePtr& scope, AstStatTypeAlias* alias)
 {
     // TODO: Exported type aliases
-    // TODO: Generic type aliases
 
-    auto it = scope->typeBindings.find(alias->name.value);
-    // This should always be here since we do a separate pass over the
-    // AST to set up typeBindings. If it's not, we've somehow skipped
-    // this alias in that first pass.
-    LUAU_ASSERT(it != scope->typeBindings.end());
-    if (it == scope->typeBindings.end())
+    auto bindingIt = scope->typeBindings.find(alias->name.value);
+    ScopePtr* defnIt = astTypeAliasDefiningScopes.find(alias);
+    // These will be undefined if the alias was a duplicate definition, in which
+    // case we just skip over it.
+    if (bindingIt == scope->typeBindings.end() || defnIt == nullptr)
     {
-        ice->ice("Type alias does not have a pre-populated binding", alias->location);
+        return;
     }
 
-    TypeId ty = resolveType(scope, alias->type);
+    ScopePtr resolvingScope = *defnIt;
+    TypeId ty = resolveType(resolvingScope, alias->type, /* topLevel */ true);
+
+    LUAU_ASSERT(get<FreeTypeVar>(bindingIt->second.type));
 
     // Rather than using a subtype constraint, we instead directly bind
     // the free type we generated in the first pass to the resolved type.
     // This prevents a case where you could cause another constraint to
     // bind the free alias type to an unrelated type, causing havoc.
-    asMutable(it->second)->ty.emplace<BoundTypeVar>(ty);
+    asMutable(bindingIt->second.type)->ty.emplace<BoundTypeVar>(ty);
 
     addConstraint(scope, NameConstraint{ty, alias->name.value});
 }
 
+void ConstraintGraphBuilder::visit(const ScopePtr& scope, AstStatDeclareGlobal* global)
+{
+    LUAU_ASSERT(global->type);
+
+    TypeId globalTy = resolveType(scope, global->type);
+    scope->bindings[global->name] = Binding{globalTy, global->location};
+}
+
+void ConstraintGraphBuilder::visit(const ScopePtr& scope, AstStatDeclareClass* global)
+{
+    LUAU_ASSERT(false); // TODO: implement
+}
+
+void ConstraintGraphBuilder::visit(const ScopePtr& scope, AstStatDeclareFunction* global)
+{
+    LUAU_ASSERT(false); // TODO: implement
+}
+
 TypePackId ConstraintGraphBuilder::checkPack(const ScopePtr& scope, AstArray<AstExpr*> exprs)
 {
     if (exprs.size == 0)
@@ -707,7 +765,7 @@ ConstraintGraphBuilder::FunctionSignature ConstraintGraphBuilder::checkFunctionS
         for (const auto& [name, g] : genericDefinitions)
         {
             genericTypes.push_back(g.ty);
-            signatureScope->typeBindings[name] = g.ty;
+            signatureScope->typeBindings[name] = TypeFun{g.ty};
         }
 
         for (const auto& [name, g] : genericPackDefinitions)
@@ -745,7 +803,7 @@ ConstraintGraphBuilder::FunctionSignature ConstraintGraphBuilder::checkFunctionS
 
         if (local->annotation)
         {
-            TypeId argAnnotation = resolveType(signatureScope, local->annotation);
+            TypeId argAnnotation = resolveType(signatureScope, local->annotation, /* topLevel */ true);
             addConstraint(signatureScope, SubtypeConstraint{t, argAnnotation});
         }
     }
@@ -784,20 +842,65 @@ void ConstraintGraphBuilder::checkFunctionBody(const ScopePtr& scope, AstExprFun
     }
 }
 
-TypeId ConstraintGraphBuilder::resolveType(const ScopePtr& scope, AstType* ty)
+TypeId ConstraintGraphBuilder::resolveType(const ScopePtr& scope, AstType* ty, bool topLevel)
 {
     TypeId result = nullptr;
 
     if (auto ref = ty->as<AstTypeReference>())
     {
         // TODO: Support imported types w/ require tracing.
-        // TODO: Support generic type references.
         LUAU_ASSERT(!ref->prefix);
-        LUAU_ASSERT(!ref->hasParameterList);
 
-        // TODO: If it doesn't exist, should we introduce a free binding?
-        // This is probably important for handling type aliases.
-        result = scope->lookupTypeBinding(ref->name.value).value_or(singletonTypes.errorRecoveryType());
+        std::optional<TypeFun> alias = scope->lookupTypeBinding(ref->name.value);
+
+        if (alias.has_value())
+        {
+            // If the alias is not generic, we don't need to set up a blocked
+            // type and an instantiation constraint.
+            if (alias->typeParams.empty() && alias->typePackParams.empty())
+            {
+                result = alias->type;
+            }
+            else
+            {
+                std::vector<TypeId> parameters;
+                std::vector<TypePackId> packParameters;
+
+                for (const AstTypeOrPack& p : ref->parameters)
+                {
+                    // We do not enforce the ordering of types vs. type packs here;
+                    // that is done in the parser.
+                    if (p.type)
+                    {
+                        parameters.push_back(resolveType(scope, p.type));
+                    }
+                    else if (p.typePack)
+                    {
+                        packParameters.push_back(resolveTypePack(scope, p.typePack));
+                    }
+                    else
+                    {
+                        // This indicates a parser bug: one of these two pointers
+                        // should be set.
+                        LUAU_ASSERT(false);
+                    }
+                }
+
+                result = arena->addType(PendingExpansionTypeVar{*alias, parameters, packParameters});
+
+                if (topLevel)
+                {
+                    addConstraint(scope, TypeAliasExpansionConstraint{
+                                             /* target */ result,
+                                         });
+                }
+            }
+        }
+        else
+        {
+            reportError(ty->location, UnknownSymbol{ref->name.value, UnknownSymbol::Context::Type});
+            result = singletonTypes.errorRecoveryType();
+        }
     }
     else if (auto tab = ty->as<AstTypeTable>())
     {
@@ -846,7 +949,7 @@ TypeId ConstraintGraphBuilder::resolveType(const ScopePtr& scope, AstType* ty)
             for (const auto& [name, g] : genericDefinitions)
             {
                 genericTypes.push_back(g.ty);
-                signatureScope->typeBindings[name] = g.ty;
+                signatureScope->typeBindings[name] = TypeFun{g.ty};
             }
 
             for (const auto& [name, g] : genericPackDefinitions)
@@ -956,7 +1059,15 @@ TypePackId ConstraintGraphBuilder::resolveTypePack(const ScopePtr& scope, AstTyp
     }
     else if (auto gen = tp->as<AstTypePackGeneric>())
     {
-        result = arena->addTypePack(TypePackVar{GenericTypePack{scope.get(), gen->genericName.value}});
+        if (std::optional<TypePackId> lookup = scope->lookupTypePackBinding(gen->genericName.value))
+        {
+            result = *lookup;
+        }
+        else
+        {
+            reportError(tp->location, UnknownSymbol{gen->genericName.value, UnknownSymbol::Context::Type});
+            result = singletonTypes.errorRecoveryTypePack();
+        }
     }
     else
     {

Analysis/src/ConstraintSolver.cpp

@@ -1,11 +1,13 @@
 // This file is part of the Luau programming language and is licensed under MIT License; see LICENSE.txt for details
 
+#include "Luau/ApplyTypeFunction.h"
 #include "Luau/ConstraintSolver.h"
 #include "Luau/Instantiation.h"
 #include "Luau/Location.h"
 #include "Luau/Quantify.h"
 #include "Luau/ToString.h"
 #include "Luau/Unifier.h"
+#include "Luau/VisitTypeVar.h"
 
 LUAU_FASTFLAGVARIABLE(DebugLuauLogSolver, false);
 LUAU_FASTFLAGVARIABLE(DebugLuauLogSolverToJson, false);
@@ -37,6 +39,170 @@ static void dumpConstraints(NotNull<Scope> scope, ToStringOptions& opts)
         dumpConstraints(child, opts);
 }
 
+static std::pair<std::vector<TypeId>, std::vector<TypePackId>> saturateArguments(
+    const TypeFun& fn, const std::vector<TypeId>& rawTypeArguments, const std::vector<TypePackId>& rawPackArguments, TypeArena* arena)
+{
+    std::vector<TypeId> saturatedTypeArguments;
+    std::vector<TypeId> extraTypes;
+    std::vector<TypePackId> saturatedPackArguments;
+
+    for (size_t i = 0; i < rawTypeArguments.size(); ++i)
+    {
+        TypeId ty = rawTypeArguments[i];
+
+        if (i < fn.typeParams.size())
+            saturatedTypeArguments.push_back(ty);
+        else
+            extraTypes.push_back(ty);
+    }
+
+    // If we collected extra types, put them in a type pack now. This case is
+    // mutually exclusive with the type pack -> type conversion we do below:
+    // extraTypes will only have elements in it if we have more types than we
+    // have parameter slots for them to go into.
+    if (!extraTypes.empty())
+    {
+        saturatedPackArguments.push_back(arena->addTypePack(extraTypes));
+    }
+
+    for (size_t i = 0; i < rawPackArguments.size(); ++i)
+    {
+        TypePackId tp = rawPackArguments[i];
+
+        // If we are short on regular type saturatedTypeArguments and we have a single
+        // element type pack, we can decompose that to the type it contains and
+        // use that as a type parameter.
+        if (saturatedTypeArguments.size() < fn.typeParams.size() && size(tp) == 1 && finite(tp) && first(tp) && saturatedPackArguments.empty())
+        {
+            saturatedTypeArguments.push_back(*first(tp));
+        }
+        else
+        {
+            saturatedPackArguments.push_back(tp);
+        }
+    }
+
+    size_t typesProvided = saturatedTypeArguments.size();
+    size_t typesRequired = fn.typeParams.size();
+
+    size_t packsProvided = saturatedPackArguments.size();
+    size_t packsRequired = fn.typePackParams.size();
+
+    // Extra types should be accumulated in extraTypes, not saturatedTypeArguments. Extra
+    // packs will be accumulated in saturatedPackArguments, so we don't have an
+    // assertion for that.
+    LUAU_ASSERT(typesProvided <= typesRequired);
+
+    // If we didn't provide enough types, but we did provide a type pack, we
+    // don't want to use defaults. The rationale for this is that if the user
+    // provides a pack but doesn't provide enough types, we want to report an
+    // error, rather than simply using the default saturatedTypeArguments, if they exist. If
+    // they did provide enough types, but not enough packs, we of course want to
+    // use the default packs.
+    bool needsDefaults = (typesProvided < typesRequired && packsProvided == 0) || (typesProvided == typesRequired && packsProvided < packsRequired);
+
+    if (needsDefaults)
+    {
+        // Default types can reference earlier types. It's legal to write
+        // something like
+        // type T<A, B = A> = (A, B) -> number
+        // and we need to respect that. We use an ApplyTypeFunction for this.
+        ApplyTypeFunction atf{arena};
+
+        for (size_t i = 0; i < typesProvided; ++i)
+            atf.typeArguments[fn.typeParams[i].ty] = saturatedTypeArguments[i];
+
+        for (size_t i = typesProvided; i < typesRequired; ++i)
+        {
+            TypeId defaultTy = fn.typeParams[i].defaultValue.value_or(nullptr);
+
+            // We will fill this in with the error type later.
+            if (!defaultTy)
+                break;
+
+            TypeId instantiatedDefault = atf.substitute(defaultTy).value_or(getSingletonTypes().errorRecoveryType());
+            atf.typeArguments[fn.typeParams[i].ty] = instantiatedDefault;
+            saturatedTypeArguments.push_back(instantiatedDefault);
+        }
+
+        for (size_t i = 0; i < packsProvided; ++i)
+        {
+            atf.typePackArguments[fn.typePackParams[i].tp] = saturatedPackArguments[i];
+        }
+
+        for (size_t i = packsProvided; i < packsRequired; ++i)
+        {
+            TypePackId defaultTp = fn.typePackParams[i].defaultValue.value_or(nullptr);
+
+            // We will fill this in with the error type pack later.
+            if (!defaultTp)
+                break;
+
+            TypePackId instantiatedDefault = atf.substitute(defaultTp).value_or(getSingletonTypes().errorRecoveryTypePack());
+            atf.typePackArguments[fn.typePackParams[i].tp] = instantiatedDefault;
+            saturatedPackArguments.push_back(instantiatedDefault);
+        }
+    }
+
+    // If we didn't create an extra type pack from overflowing parameter packs,
+    // and we're still missing a type pack, plug in an empty type pack as the
+    // value of the empty packs.
+    if (extraTypes.empty() && saturatedPackArguments.size() + 1 == fn.typePackParams.size())
+    {
+        saturatedPackArguments.push_back(arena->addTypePack({}));
+    }
+
+    // We need to have _something_ when we substitute the generic saturatedTypeArguments,
+    // even if they're missing, so we use the error type as a filler.
+    for (size_t i = saturatedTypeArguments.size(); i < typesRequired; ++i)
+    {
+        saturatedTypeArguments.push_back(getSingletonTypes().errorRecoveryType());
+    }
+
+    for (size_t i = saturatedPackArguments.size(); i < packsRequired; ++i)
+    {
+        saturatedPackArguments.push_back(getSingletonTypes().errorRecoveryTypePack());
+    }
+
+    // At this point, these two conditions should be true. If they aren't we
+    // will run into access violations.
+    LUAU_ASSERT(saturatedTypeArguments.size() == fn.typeParams.size());
+    LUAU_ASSERT(saturatedPackArguments.size() == fn.typePackParams.size());
+
+    return {saturatedTypeArguments, saturatedPackArguments};
+}
+
+bool InstantiationSignature::operator==(const InstantiationSignature& rhs) const
+{
+    return fn == rhs.fn && arguments == rhs.arguments && packArguments == rhs.packArguments;
+}
+
+size_t HashInstantiationSignature::operator()(const InstantiationSignature& signature) const
+{
+    size_t hash = std::hash<TypeId>{}(signature.fn.type);
+    for (const GenericTypeDefinition& p : signature.fn.typeParams)
+    {
+        hash ^= (std::hash<TypeId>{}(p.ty) << 1);
+    }
+
+    for (const GenericTypePackDefinition& p : signature.fn.typePackParams)
+    {
+        hash ^= (std::hash<TypePackId>{}(p.tp) << 1);
+    }
+
+    for (const TypeId a : signature.arguments)
+    {
+        hash ^= (std::hash<TypeId>{}(a) << 1);
+    }
+
+    for (const TypePackId a : signature.packArguments)
+    {
+        hash ^= (std::hash<TypePackId>{}(a) << 1);
+    }
+
+    return hash;
+}
+
 void dump(NotNull<Scope> rootScope, ToStringOptions& opts)
 {
     printf("constraints:\n");
@@ -77,6 +243,7 @@ void ConstraintSolver::run()
         return;
 
     ToStringOptions opts;
+    opts.exhaustive = true;
 
     if (FFlag::DebugLuauLogSolver)
     {
@@ -186,6 +353,8 @@ bool ConstraintSolver::tryDispatch(NotNull<const Constraint> constraint, bool fo
         success = tryDispatch(*bc, constraint, force);
     else if (auto nc = get<NameConstraint>(*constraint))
         success = tryDispatch(*nc, constraint);
+    else if (auto taec = get<TypeAliasExpansionConstraint>(*constraint))
+        success = tryDispatch(*taec, constraint);
     else
         LUAU_ASSERT(0);
 
@@ -325,6 +494,198 @@ bool ConstraintSolver::tryDispatch(const NameConstraint& c, NotNull<const Constr
     return true;
 }
 
+struct InfiniteTypeFinder : TypeVarOnceVisitor
+{
+    ConstraintSolver* solver;
+    const InstantiationSignature& signature;
+    bool foundInfiniteType = false;
+
+    explicit InfiniteTypeFinder(ConstraintSolver* solver, const InstantiationSignature& signature)
+        : solver(solver)
+        , signature(signature)
+    {
+    }
+
+    bool visit(TypeId ty, const PendingExpansionTypeVar& petv) override
+    {
+        auto [typeArguments, packArguments] = saturateArguments(petv.fn, petv.typeArguments, petv.packArguments, solver->arena);
+
+        if (follow(petv.fn.type) == follow(signature.fn.type) && (signature.arguments != typeArguments || signature.packArguments != packArguments))
+        {
+            foundInfiniteType = true;
+            return false;
+        }
+
+        return true;
+    }
+};
+
+struct InstantiationQueuer : TypeVarOnceVisitor
+{
+    ConstraintSolver* solver;
+    const InstantiationSignature& signature;
+
+    explicit InstantiationQueuer(ConstraintSolver* solver, const InstantiationSignature& signature)
+        : solver(solver)
+        , signature(signature)
+    {
+    }
+
+    bool visit(TypeId ty, const PendingExpansionTypeVar& petv) override
+    {
+        solver->pushConstraint(TypeAliasExpansionConstraint{ty});
+        return false;
+    }
+};
+
+bool ConstraintSolver::tryDispatch(const TypeAliasExpansionConstraint& c, NotNull<const Constraint> constraint)
+{
+    const PendingExpansionTypeVar* petv = get<PendingExpansionTypeVar>(follow(c.target));
+    if (!petv)
+    {
+        unblock(c.target);
+        return true;
+    }
+
+    auto bindResult = [this, &c](TypeId result) {
+        asMutable(c.target)->ty.emplace<BoundTypeVar>(result);
+        unblock(c.target);
+    };
+
+    // If there are no parameters to the type function we can just use the type
+    // directly.
+    if (petv->fn.typeParams.empty() && petv->fn.typePackParams.empty())
+    {
+        bindResult(petv->fn.type);
+        return true;
+    }
+
+    auto [typeArguments, packArguments] = saturateArguments(petv->fn, petv->typeArguments, petv->packArguments, arena);
+
+    bool sameTypes =
+        std::equal(typeArguments.begin(), typeArguments.end(), petv->fn.typeParams.begin(), petv->fn.typeParams.end(), [](auto&& itp, auto&& p) {
+            return itp == p.ty;
+        });
+
+    bool samePacks = std::equal(
+        packArguments.begin(), packArguments.end(), petv->fn.typePackParams.begin(), petv->fn.typePackParams.end(), [](auto&& itp, auto&& p) {
+            return itp == p.tp;
+        });
+
+    // If we're instantiating the type with its generic saturatedTypeArguments we are
+    // performing the identity substitution. We can just short-circuit and bind
+    // to the TypeFun's type.
+    if (sameTypes && samePacks)
+    {
+        bindResult(petv->fn.type);
+        return true;
+    }
+
+    InstantiationSignature signature{
+        petv->fn,
+        typeArguments,
+        packArguments,
+    };
+
+    // If we use the same signature, we don't need to bother trying to
+    // instantiate the alias again, since the instantiation should be
+    // deterministic.
+    if (TypeId* cached = instantiatedAliases.find(signature))
+    {
+        bindResult(*cached);
+        return true;
+    }
+
+    // In order to prevent infinite types from being expanded and causing us to
+    // cycle infinitely, we need to scan the type function for cases where we
+    // expand the same alias with different type saturatedTypeArguments. See
+    // https://github.com/Roblox/luau/pull/68 for the RFC responsible for this.
+    // This is a little nicer than using a recursion limit because we can catch
+    // the infinite expansion before actually trying to expand it.
+    InfiniteTypeFinder itf{this, signature};
+    itf.traverse(petv->fn.type);
+
+    if (itf.foundInfiniteType)
+    {
+        // TODO (CLI-56761): Report an error.
+        bindResult(getSingletonTypes().errorRecoveryType());
+        return true;
+    }
+
+    ApplyTypeFunction applyTypeFunction{arena};
+    for (size_t i = 0; i < typeArguments.size(); ++i)
+    {
+        applyTypeFunction.typeArguments[petv->fn.typeParams[i].ty] = typeArguments[i];
+    }
+
+    for (size_t i = 0; i < packArguments.size(); ++i)
+    {
+        applyTypeFunction.typePackArguments[petv->fn.typePackParams[i].tp] = packArguments[i];
+    }
+
+    std::optional<TypeId> maybeInstantiated = applyTypeFunction.substitute(petv->fn.type);
+    // Note that ApplyTypeFunction::encounteredForwardedType is never set in
+    // DCR, because we do not use free types for forward-declared generic
+    // aliases.
+
+    if (!maybeInstantiated.has_value())
+    {
+        // TODO (CLI-56761): Report an error.
+        bindResult(getSingletonTypes().errorRecoveryType());
+        return true;
+    }
+
+    TypeId instantiated = *maybeInstantiated;
+    TypeId target = follow(instantiated);
+    // Type function application will happily give us the exact same type if
+    // there are e.g. generic saturatedTypeArguments that go unused.
+    bool needsClone = follow(petv->fn.type) == target;
+    // Only tables have the properties we're trying to set.
+    TableTypeVar* ttv = getMutableTableType(target);
+
+    if (ttv)
+    {
+        if (needsClone)
+        {
+            // Substitution::clone is a shallow clone. If this is a
+            // metatable type, we want to mutate its table, so we need to
+            // explicitly clone that table as well. If we don't, we will
+            // mutate another module's type surface and cause a
+            // use-after-free.
+            if (get<MetatableTypeVar>(target))
+            {
+                instantiated = applyTypeFunction.clone(target);
+                MetatableTypeVar* mtv = getMutable<MetatableTypeVar>(instantiated);
+                mtv->table = applyTypeFunction.clone(mtv->table);
+                ttv = getMutable<TableTypeVar>(mtv->table);
+            }
+            else if (get<TableTypeVar>(target))
+            {
+                instantiated = applyTypeFunction.clone(target);
+                ttv = getMutable<TableTypeVar>(instantiated);
+            }
+
+            target = follow(instantiated);
+        }
+
+        ttv->instantiatedTypeParams = typeArguments;
+        ttv->instantiatedTypePackParams = packArguments;
+        // TODO: Fill in definitionModuleName.
+    }
+
+    bindResult(target);
+
+    // The application is not recursive, so we need to queue up application of
+    // any child type function instantiations within the result in order for it
+    // to be complete.
+    InstantiationQueuer queuer{this, signature};
+    queuer.traverse(target);
+
+    instantiatedAliases[signature] = target;
+
+    return true;
+}
+
 void ConstraintSolver::block_(BlockedConstraintId target, NotNull<const Constraint> constraint)
 {
     blocked[target].push_back(constraint);
@@ -388,7 +749,7 @@ void ConstraintSolver::unblock(TypePackId progressed)
 
 bool ConstraintSolver::isBlocked(TypeId ty)
 {
-    return nullptr != get<BlockedTypeVar>(follow(ty));
+    return nullptr != get<BlockedTypeVar>(follow(ty)) || nullptr != get<PendingExpansionTypeVar>(follow(ty));
 }
 
 bool ConstraintSolver::isBlocked(NotNull<const Constraint> constraint)
@@ -415,4 +776,12 @@ void ConstraintSolver::unify(TypePackId subPack, TypePackId superPack)
     u.log.commit();
 }
 
+void ConstraintSolver::pushConstraint(ConstraintV cv)
+{
+    std::unique_ptr<Constraint> c = std::make_unique<Constraint>(std::move(cv));
+    NotNull<Constraint> borrow = NotNull(c.get());
+    solverConstraints.push_back(std::move(c));
+    unsolvedConstraints.push_back(borrow);
+}
+
 } // namespace Luau

Analysis/src/ConstraintSolverLogger.cpp

@@ -2,45 +2,39 @@
 
 #include "Luau/ConstraintSolverLogger.h"
 
+#include "Luau/JsonEmitter.h"
+
 namespace Luau
 {
 
-static std::string dumpScopeAndChildren(const Scope* scope, ToStringOptions& opts)
+static void dumpScopeAndChildren(const Scope* scope, Json::JsonEmitter& emitter, ToStringOptions& opts)
 {
-    std::string output = "{\"bindings\":{";
+    emitter.writeRaw("{");
+    Json::write(emitter, "bindings");
+    emitter.writeRaw(":");
+
+    Json::ObjectEmitter o = emitter.writeObject();
 
-    bool comma = false;
     for (const auto& [name, binding] : scope->bindings)
     {
-        if (comma)
-            output += ",";
-
-        output += "\"";
-        output += name.c_str();
-        output += "\": \"";
-
         ToStringResult result = toStringDetailed(binding.typeId, opts);
         opts.nameMap = std::move(result.nameMap);
-        output += result.name;
-        output += "\"";
-
-        comma = true;
+        o.writePair(name.c_str(), result.name);
     }
 
-    output += "},\"children\":[";
-    comma = false;
+    o.finish();
+    emitter.writeRaw(",");
+    Json::write(emitter, "children");
+    emitter.writeRaw(":");
 
+    Json::ArrayEmitter a = emitter.writeArray();
     for (const Scope* child : scope->children)
     {
-        if (comma)
-            output += ",";
-
-        output += dumpScopeAndChildren(child, opts);
-        comma = true;
+        dumpScopeAndChildren(child, emitter, opts);
     }
 
-    output += "]}";
-    return output;
+    a.finish();
+    emitter.writeRaw("}");
 }
 
 static std::string dumpConstraintsToDot(std::vector<NotNull<const Constraint>>& constraints, ToStringOptions& opts)
@@ -80,51 +74,49 @@ static std::string dumpConstraintsToDot(std::vector<NotNull<const Constraint>>&
 
 std::string ConstraintSolverLogger::compileOutput()
 {
-    std::string output = "[";
-    bool comma = false;
-
+    Json::JsonEmitter emitter;
+    emitter.writeRaw("[");
     for (const std::string& snapshot : snapshots)
     {
-        if (comma)
-            output += ",";
-        output += snapshot;
-
-        comma = true;
+        emitter.writeComma();
+        emitter.writeRaw(snapshot);
     }
 
-    output += "]";
-    return output;
+    emitter.writeRaw("]");
+    return emitter.str();
 }
 
 void ConstraintSolverLogger::captureBoundarySnapshot(const Scope* rootScope, std::vector<NotNull<const Constraint>>& unsolvedConstraints)
 {
-    std::string snapshot = "{\"type\":\"boundary\",\"rootScope\":";
+    Json::JsonEmitter emitter;
+    Json::ObjectEmitter o = emitter.writeObject();
+    o.writePair("type", "boundary");
+    o.writePair("constraintGraph", dumpConstraintsToDot(unsolvedConstraints, opts));
+    emitter.writeComma();
+    Json::write(emitter, "rootScope");
+    emitter.writeRaw(":");
+    dumpScopeAndChildren(rootScope, emitter, opts);
+    o.finish();
 
-    snapshot += dumpScopeAndChildren(rootScope, opts);
-    snapshot += ",\"constraintGraph\":\"";
-    snapshot += dumpConstraintsToDot(unsolvedConstraints, opts);
-    snapshot += "\"}";
-
-    snapshots.push_back(std::move(snapshot));
+    snapshots.push_back(emitter.str());
 }
 
 void ConstraintSolverLogger::prepareStepSnapshot(
     const Scope* rootScope, NotNull<const Constraint> current, std::vector<NotNull<const Constraint>>& unsolvedConstraints)
 {
-    // LUAU_ASSERT(!preparedSnapshot);
+    Json::JsonEmitter emitter;
+    Json::ObjectEmitter o = emitter.writeObject();
+    o.writePair("type", "step");
+    o.writePair("constraintGraph", dumpConstraintsToDot(unsolvedConstraints, opts));
+    o.writePair("currentId", std::to_string(reinterpret_cast<size_t>(current.get())));
+    o.writePair("current", toString(*current, opts));
+    emitter.writeComma();
+    Json::write(emitter, "rootScope");
+    emitter.writeRaw(":");
+    dumpScopeAndChildren(rootScope, emitter, opts);
+    o.finish();
 
-    std::string snapshot = "{\"type\":\"step\",\"rootScope\":";
-
-    snapshot += dumpScopeAndChildren(rootScope, opts);
-    snapshot += ",\"constraintGraph\":\"";
-    snapshot += dumpConstraintsToDot(unsolvedConstraints, opts);
-    snapshot += "\",\"currentId\":\"";
-    snapshot += std::to_string(reinterpret_cast<size_t>(current.get()));
-    snapshot += "\",\"current\":\"";
-    snapshot += toString(*current, opts);
-    snapshot += "\"}";
-
-    preparedSnapshot = std::move(snapshot);
+    preparedSnapshot = emitter.str();
 }
 
 void ConstraintSolverLogger::commitPreparedStepSnapshot()

Analysis/src/Frontend.cpp

@@ -77,6 +77,58 @@ static void generateDocumentationSymbols(TypeId ty, const std::string& rootName)
     }
 }
 
+LoadDefinitionFileResult Frontend::loadDefinitionFile(std::string_view source, const std::string& packageName)
+{
+    if (!FFlag::DebugLuauDeferredConstraintResolution)
+        return Luau::loadDefinitionFile(typeChecker, typeChecker.globalScope, source, packageName);
+
+    LUAU_TIMETRACE_SCOPE("loadDefinitionFile", "Frontend");
+
+    Luau::Allocator allocator;
+    Luau::AstNameTable names(allocator);
+
+    ParseOptions options;
+    options.allowDeclarationSyntax = true;
+
+    Luau::ParseResult parseResult = Luau::Parser::parse(source.data(), source.size(), names, allocator, options);
+
+    if (parseResult.errors.size() > 0)
+        return LoadDefinitionFileResult{false, parseResult, nullptr};
+
+    Luau::SourceModule module;
+    module.root = parseResult.root;
+    module.mode = Mode::Definition;
+
+    ModulePtr checkedModule = check(module, Mode::Definition, globalScope);
+
+    if (checkedModule->errors.size() > 0)
+        return LoadDefinitionFileResult{false, parseResult, checkedModule};
+
+    CloneState cloneState;
+
+    for (const auto& [name, ty] : checkedModule->declaredGlobals)
+    {
+        TypeId globalTy = clone(ty, globalTypes, cloneState);
+        std::string documentationSymbol = packageName + "/global/" + name;
+        generateDocumentationSymbols(globalTy, documentationSymbol);
+        globalScope->bindings[typeChecker.globalNames.names->getOrAdd(name.c_str())] = {globalTy, Location(), false, {}, documentationSymbol};
+
+        persist(globalTy);
+    }
+
+    for (const auto& [name, ty] : checkedModule->getModuleScope()->exportedTypeBindings)
+    {
+        TypeFun globalTy = clone(ty, globalTypes, cloneState);
+        std::string documentationSymbol = packageName + "/globaltype/" + name;
+        generateDocumentationSymbols(globalTy.type, documentationSymbol);
+        globalScope->exportedTypeBindings[name] = globalTy;
+
+        persist(globalTy.type);
+    }
+
+    return LoadDefinitionFileResult{true, parseResult, checkedModule};
+}
+
 LoadDefinitionFileResult loadDefinitionFile(TypeChecker& typeChecker, ScopePtr targetScope, std::string_view source, const std::string& packageName)
 {
     LUAU_TIMETRACE_SCOPE("loadDefinitionFile", "Frontend");
@@ -770,14 +822,7 @@ NotNull<Scope> Frontend::getGlobalScope()
 {
     if (!globalScope)
     {
-        const SingletonTypes& singletonTypes = getSingletonTypes();
-
-        globalScope = std::make_unique<Scope>(singletonTypes.anyTypePack);
-        globalScope->typeBindings["nil"] = singletonTypes.nilType;
-        globalScope->typeBindings["number"] = singletonTypes.numberType;
-        globalScope->typeBindings["string"] = singletonTypes.stringType;
-        globalScope->typeBindings["boolean"] = singletonTypes.booleanType;
-        globalScope->typeBindings["thread"] = singletonTypes.threadType;
+        globalScope = typeChecker.globalScope;
     }
 
     return NotNull(globalScope.get());

Analysis/src/Instantiation.cpp

@@ -4,6 +4,8 @@
 #include "Luau/TxnLog.h"
 #include "Luau/TypeArena.h"
 
+LUAU_FASTFLAG(LuauClassTypeVarsInSubstitution)
+
 namespace Luau
 {
 
@@ -31,6 +33,8 @@ bool Instantiation::ignoreChildren(TypeId ty)
 {
     if (log->getMutable<FunctionTypeVar>(ty))
         return true;
+    else if (FFlag::LuauClassTypeVarsInSubstitution && get<ClassTypeVar>(ty))
+        return true;
     else
         return false;
 }

Analysis/src/JsonEmitter.cpp

@@ -0,0 +1,220 @@
+// This file is part of the Luau programming language and is licensed under MIT License; see LICENSE.txt for details
+#include "Luau/JsonEmitter.h"
+
+#include "Luau/StringUtils.h"
+
+#include <string.h>
+
+namespace Luau::Json
+{
+
+static constexpr int CHUNK_SIZE = 1024;
+
+ObjectEmitter::ObjectEmitter(NotNull<JsonEmitter> emitter)
+    : emitter(emitter), finished(false)
+{
+    comma = emitter->pushComma();
+    emitter->writeRaw('{');
+}
+
+ObjectEmitter::~ObjectEmitter()
+{
+    finish();
+}
+
+void ObjectEmitter::finish()
+{
+    if (finished)
+        return;
+
+    emitter->writeRaw('}');
+    emitter->popComma(comma);
+    finished = true;
+}
+
+ArrayEmitter::ArrayEmitter(NotNull<JsonEmitter> emitter)
+    : emitter(emitter), finished(false)
+{
+    comma = emitter->pushComma();
+    emitter->writeRaw('[');
+}
+
+ArrayEmitter::~ArrayEmitter()
+{
+    finish();
+}
+
+void ArrayEmitter::finish()
+{
+    if (finished)
+        return;
+
+    emitter->writeRaw(']');
+    emitter->popComma(comma);
+    finished = true;
+}
+
+JsonEmitter::JsonEmitter()
+{
+    newChunk();
+}
+
+std::string JsonEmitter::str()
+{
+    return join(chunks, "");
+}
+
+bool JsonEmitter::pushComma()
+{
+    bool current = comma;
+    comma = false;
+    return current;
+}
+
+void JsonEmitter::popComma(bool c)
+{
+    comma = c;
+}
+
+void JsonEmitter::writeRaw(std::string_view sv)
+{
+    if (sv.size() > CHUNK_SIZE)
+    {
+        chunks.emplace_back(sv);
+        newChunk();
+        return;
+    }
+
+    auto& chunk = chunks.back();
+    if (chunk.size() + sv.size() < CHUNK_SIZE)
+    {
+        chunk.append(sv.data(), sv.size());
+        return;
+    }
+
+    size_t prefix = CHUNK_SIZE - chunk.size();
+    chunk.append(sv.data(), prefix);
+    newChunk();
+
+    chunks.back().append(sv.data() + prefix, sv.size() - prefix);
+}
+
+void JsonEmitter::writeRaw(char c)
+{
+    writeRaw(std::string_view{&c, 1});
+}
+
+void write(JsonEmitter& emitter, bool b)
+{
+    if (b)
+        emitter.writeRaw("true");
+    else
+        emitter.writeRaw("false");
+}
+
+void write(JsonEmitter& emitter, double d)
+{
+    emitter.writeRaw(std::to_string(d));
+}
+
+void write(JsonEmitter& emitter, int i)
+{
+    emitter.writeRaw(std::to_string(i));
+}
+
+void write(JsonEmitter& emitter, long i)
+{
+    emitter.writeRaw(std::to_string(i));
+}
+
+void write(JsonEmitter& emitter, long long i)
+{
+    emitter.writeRaw(std::to_string(i));
+}
+
+void write(JsonEmitter& emitter, unsigned int i)
+{
+    emitter.writeRaw(std::to_string(i));
+}
+
+void write(JsonEmitter& emitter, unsigned long i)
+{
+    emitter.writeRaw(std::to_string(i));
+}
+
+void write(JsonEmitter& emitter, unsigned long long i)
+{
+    emitter.writeRaw(std::to_string(i));
+}
+
+void write(JsonEmitter& emitter, std::string_view sv)
+{
+    emitter.writeRaw('\"');
+
+    for (char c : sv)
+    {
+        if (c == '"')
+            emitter.writeRaw("\\\"");
+        else if (c == '\\')
+            emitter.writeRaw("\\\\");
+        else if (c == '\n')
+            emitter.writeRaw("\\n");
+        else if (c < ' ')
+            emitter.writeRaw(format("\\u%04x", c));
+        else
+            emitter.writeRaw(c);
+    }
+
+    emitter.writeRaw('\"');
+}
+
+void write(JsonEmitter& emitter, char c)
+{
+    write(emitter, std::string_view{&c, 1});
+}
+
+void write(JsonEmitter& emitter, const char* str)
+{
+    write(emitter, std::string_view{str, strlen(str)});
+}
+
+void write(JsonEmitter& emitter, const std::string& str)
+{
+    write(emitter, std::string_view{str});
+}
+
+void write(JsonEmitter& emitter, std::nullptr_t)
+{
+    emitter.writeRaw("null");
+}
+
+void write(JsonEmitter& emitter, std::nullopt_t)
+{
+    emitter.writeRaw("null");
+}
+
+void JsonEmitter::writeComma()
+{
+    if (comma)
+        writeRaw(',');
+    else
+        comma = true;
+}
+
+ObjectEmitter JsonEmitter::writeObject()
+{
+    return ObjectEmitter{NotNull(this)};
+}
+
+ArrayEmitter JsonEmitter::writeArray()
+{
+    return ArrayEmitter{NotNull(this)};
+}
+
+void JsonEmitter::newChunk()
+{
+    chunks.emplace_back();
+    chunks.back().reserve(CHUNK_SIZE);
+}
+
+} // namespace Luau::Json

Analysis/src/Linter.cpp

@@ -48,6 +48,7 @@ static const char* kWarningNames[] = {
     "DuplicateCondition",
     "MisleadingAndOr",
     "CommentDirective",
+    "IntegerParsing",
 };
 // clang-format on
 
@@ -2589,6 +2590,45 @@ private:
     }
 };
 
+class LintIntegerParsing : AstVisitor
+{
+public:
+    LUAU_NOINLINE static void process(LintContext& context)
+    {
+        LintIntegerParsing pass;
+        pass.context = &context;
+
+        context.root->visit(&pass);
+    }
+
+private:
+    LintContext* context;
+
+    bool visit(AstExprConstantNumber* node) override
+    {
+        switch (node->parseResult)
+        {
+        case ConstantNumberParseResult::Ok:
+        case ConstantNumberParseResult::Malformed:
+            break;
+        case ConstantNumberParseResult::BinOverflow:
+            emitWarning(*context, LintWarning::Code_IntegerParsing, node->location,
+                "Binary number literal exceeded available precision and has been truncated to 2^64");
+            break;
+        case ConstantNumberParseResult::HexOverflow:
+            emitWarning(*context, LintWarning::Code_IntegerParsing, node->location,
+                "Hexadecimal number literal exceeded available precision and has been truncated to 2^64");
+            break;
+        case ConstantNumberParseResult::DoublePrefix:
+            emitWarning(*context, LintWarning::Code_IntegerParsing, node->location,
+                "Hexadecimal number literal has a double prefix, which will fail to parse in the future; remove the extra 0x to fix");
+            break;
+        }
+
+        return true;
+    }
+};
+
 static void fillBuiltinGlobals(LintContext& context, const AstNameTable& names, const ScopePtr& env)
 {
     ScopePtr current = env;
@@ -2810,6 +2850,9 @@ std::vector<LintWarning> lint(AstStat* root, const AstNameTable& names, const Sc
     if (context.warningEnabled(LintWarning::Code_CommentDirective))
         lintComments(context, hotcomments);
 
+    if (context.warningEnabled(LintWarning::Code_IntegerParsing))
+        LintIntegerParsing::process(context);
+
     std::sort(context.result.begin(), context.result.end(), WarningComparator());
 
     return context.result;

Analysis/src/Module.cpp

@@ -15,7 +15,6 @@
 #include <algorithm>
 
 LUAU_FASTFLAG(LuauLowerBoundsCalculation);
-LUAU_FASTFLAG(LuauNormalizeFlagIsConservative);
 LUAU_FASTFLAG(DebugLuauDeferredConstraintResolution);
 LUAU_FASTFLAGVARIABLE(LuauForceExportSurfacesToBeNormal, false);
 
@@ -140,20 +139,17 @@ void Module::clonePublicInterface(InternalErrorReporter& ice)
             {
                 normalize(tf.type, interfaceTypes, ice);
 
-                if (FFlag::LuauNormalizeFlagIsConservative)
+                // We're about to freeze the memory.  We know that the flag is conservative by design.  Cyclic tables
+                // won't be marked normal.  If the types aren't normal by now, they never will be.
+                forceNormal.traverse(tf.type);
+                for (GenericTypeDefinition param : tf.typeParams)
                 {
-                    // We're about to freeze the memory.  We know that the flag is conservative by design.  Cyclic tables
-                    // won't be marked normal.  If the types aren't normal by now, they never will be.
-                    forceNormal.traverse(tf.type);
-                    for (GenericTypeDefinition param : tf.typeParams)
-                    {
-                        forceNormal.traverse(param.ty);
+                    forceNormal.traverse(param.ty);
 
-                        if (param.defaultValue)
-                        {
-                            normalize(*param.defaultValue, interfaceTypes, ice);
-                            forceNormal.traverse(*param.defaultValue);
-                        }
+                    if (param.defaultValue)
+                    {
+                        normalize(*param.defaultValue, interfaceTypes, ice);
+                        forceNormal.traverse(*param.defaultValue);
                     }
                 }
             }

Analysis/src/Normalize.cpp

@@ -13,7 +13,6 @@ LUAU_FASTFLAGVARIABLE(DebugLuauCopyBeforeNormalizing, false)
 // This could theoretically be 2000 on amd64, but x86 requires this.
 LUAU_FASTINTVARIABLE(LuauNormalizeIterationLimit, 1200);
 LUAU_FASTFLAGVARIABLE(LuauNormalizeCombineTableFix, false);
-LUAU_FASTFLAGVARIABLE(LuauNormalizeFlagIsConservative, false);
 LUAU_FASTFLAGVARIABLE(LuauFixNormalizationOfCyclicUnions, false);
 LUAU_FASTFLAG(LuauUnknownAndNeverType)
 LUAU_FASTFLAG(LuauQuantifyConstrained)
@@ -89,13 +88,7 @@ static bool areNormal_(const T& t, const std::unordered_set<void*>& seen, Intern
         if (count >= FInt::LuauNormalizeIterationLimit)
             ice.ice("Luau::areNormal hit iteration limit");
 
-        if (FFlag::LuauNormalizeFlagIsConservative)
-            return ty->normal;
-        else
-        {
-            // The follow is here because a bound type may not be normal, but the bound type is normal.
-            return ty->normal || follow(ty)->normal || seen.find(asMutable(ty)) != seen.end();
-        }
+        return ty->normal;
     };
 
     return std::all_of(begin(t), end(t), isNormal);

Analysis/src/Quantify.cpp

@@ -7,7 +7,6 @@
 #include "Luau/TxnLog.h"
 #include "Luau/VisitTypeVar.h"
 
-LUAU_FASTFLAG(LuauAlwaysQuantify);
 LUAU_FASTFLAG(DebugLuauSharedSelf)
 LUAU_FASTFLAG(DebugLuauDeferredConstraintResolution);
 LUAU_FASTFLAGVARIABLE(LuauQuantifyConstrained, false)
@@ -203,16 +202,8 @@ void quantify(TypeId ty, TypeLevel level)
 
         FunctionTypeVar* ftv = getMutable<FunctionTypeVar>(ty);
         LUAU_ASSERT(ftv);
-        if (FFlag::LuauAlwaysQuantify)
-        {
-            ftv->generics.insert(ftv->generics.end(), q.generics.begin(), q.generics.end());
-            ftv->genericPacks.insert(ftv->genericPacks.end(), q.genericPacks.begin(), q.genericPacks.end());
-        }
-        else
-        {
-            ftv->generics = q.generics;
-            ftv->genericPacks = q.genericPacks;
-        }
+        ftv->generics.insert(ftv->generics.end(), q.generics.begin(), q.generics.end());
+        ftv->genericPacks.insert(ftv->genericPacks.end(), q.genericPacks.begin(), q.genericPacks.end());
     }
 }
 
@@ -223,16 +214,8 @@ void quantify(TypeId ty, Scope* scope)
 
     FunctionTypeVar* ftv = getMutable<FunctionTypeVar>(ty);
     LUAU_ASSERT(ftv);
-    if (FFlag::LuauAlwaysQuantify)
-    {
-        ftv->generics.insert(ftv->generics.end(), q.generics.begin(), q.generics.end());
-        ftv->genericPacks.insert(ftv->genericPacks.end(), q.genericPacks.begin(), q.genericPacks.end());
-    }
-    else
-    {
-        ftv->generics = q.generics;
-        ftv->genericPacks = q.genericPacks;
-    }
+    ftv->generics.insert(ftv->generics.end(), q.generics.begin(), q.generics.end());
+    ftv->genericPacks.insert(ftv->genericPacks.end(), q.genericPacks.begin(), q.genericPacks.end());
 
     if (ftv->generics.empty() && ftv->genericPacks.empty() && !q.seenMutableType && !q.seenGenericType)
         ftv->hasNoGenerics = true;

Analysis/src/Scope.cpp

@@ -122,7 +122,7 @@ std::optional<TypeId> Scope::lookup(Symbol sym)
     }
 }
 
-std::optional<TypeId> Scope::lookupTypeBinding(const Name& name)
+std::optional<TypeFun> Scope::lookupTypeBinding(const Name& name)
 {
     Scope* s = this;
     while (s)

Analysis/src/Substitution.cpp

@@ -9,9 +9,12 @@
 #include <stdexcept>
 
 LUAU_FASTFLAGVARIABLE(LuauAnyificationMustClone, false)
+LUAU_FASTFLAGVARIABLE(LuauSubstitutionFixMissingFields, false)
 LUAU_FASTFLAG(LuauLowerBoundsCalculation)
 LUAU_FASTINTVARIABLE(LuauTarjanChildLimit, 10000)
+LUAU_FASTFLAGVARIABLE(LuauClassTypeVarsInSubstitution, false)
 LUAU_FASTFLAG(LuauUnknownAndNeverType)
+LUAU_FASTFLAGVARIABLE(LuauSubstitutionReentrant, false)
 
 namespace Luau
 {
@@ -28,6 +31,14 @@ void Tarjan::visitChildren(TypeId ty, int index)
 
     if (const FunctionTypeVar* ftv = get<FunctionTypeVar>(ty))
     {
+        if (FFlag::LuauSubstitutionFixMissingFields)
+        {
+            for (TypeId generic : ftv->generics)
+                visitChild(generic);
+            for (TypePackId genericPack : ftv->genericPacks)
+                visitChild(genericPack);
+        }
+
         visitChild(ftv->argTypes);
         visitChild(ftv->retTypes);
     }
@@ -68,6 +79,25 @@ void Tarjan::visitChildren(TypeId ty, int index)
         for (TypeId part : ctv->parts)
             visitChild(part);
     }
+    else if (const PendingExpansionTypeVar* petv = get<PendingExpansionTypeVar>(ty))
+    {
+        for (TypeId a : petv->typeArguments)
+            visitChild(a);
+
+        for (TypePackId a : petv->packArguments)
+            visitChild(a);
+    }
+    else if (const ClassTypeVar* ctv = get<ClassTypeVar>(ty); FFlag::LuauClassTypeVarsInSubstitution && ctv)
+    {
+        for (auto [name, prop] : ctv->props)
+            visitChild(prop.type);
+
+        if (ctv->parent)
+            visitChild(*ctv->parent);
+
+        if (ctv->metatable)
+            visitChild(*ctv->metatable);
+    }
 }
 
 void Tarjan::visitChildren(TypePackId tp, int index)
@@ -267,6 +297,24 @@ TarjanResult Tarjan::visitRoot(TypePackId tp)
     return loop();
 }
 
+void FindDirty::clearTarjan()
+{
+    dirty.clear();
+
+    typeToIndex.clear();
+    packToIndex.clear();
+    indexToType.clear();
+    indexToPack.clear();
+
+    stack.clear();
+    onStack.clear();
+    lowlink.clear();
+
+    edgesTy.clear();
+    edgesTp.clear();
+    worklist.clear();
+}
+
 bool FindDirty::getDirty(int index)
 {
     if (dirty.size() <= size_t(index))
@@ -330,16 +378,46 @@ std::optional<TypeId> Substitution::substitute(TypeId ty)
 {
     ty = log->follow(ty);
 
+    // clear algorithm state for reentrancy
+    if (FFlag::LuauSubstitutionReentrant)
+        clearTarjan();
+
     auto result = findDirty(ty);
     if (result != TarjanResult::Ok)
         return std::nullopt;
 
     for (auto [oldTy, newTy] : newTypes)
-        if (!ignoreChildren(oldTy))
-            replaceChildren(newTy);
+    {
+        if (FFlag::LuauSubstitutionReentrant)
+        {
+            if (!ignoreChildren(oldTy) && !replacedTypes.contains(newTy))
+            {
+                replaceChildren(newTy);
+                replacedTypes.insert(newTy);
+            }
+        }
+        else
+        {
+            if (!ignoreChildren(oldTy))
+                replaceChildren(newTy);
+        }
+    }
     for (auto [oldTp, newTp] : newPacks)
-        if (!ignoreChildren(oldTp))
-            replaceChildren(newTp);
+    {
+        if (FFlag::LuauSubstitutionReentrant)
+        {
+            if (!ignoreChildren(oldTp) && !replacedTypePacks.contains(newTp))
+            {
+                replaceChildren(newTp);
+                replacedTypePacks.insert(newTp);
+            }
+        }
+        else
+        {
+            if (!ignoreChildren(oldTp))
+                replaceChildren(newTp);
+        }
+    }
     TypeId newTy = replace(ty);
     return newTy;
 }
@@ -348,16 +426,46 @@ std::optional<TypePackId> Substitution::substitute(TypePackId tp)
 {
     tp = log->follow(tp);
 
+    // clear algorithm state for reentrancy
+    if (FFlag::LuauSubstitutionReentrant)
+        clearTarjan();
+
     auto result = findDirty(tp);
     if (result != TarjanResult::Ok)
         return std::nullopt;
 
     for (auto [oldTy, newTy] : newTypes)
-        if (!ignoreChildren(oldTy))
-            replaceChildren(newTy);
+    {
+        if (FFlag::LuauSubstitutionReentrant)
+        {
+            if (!ignoreChildren(oldTy) && !replacedTypes.contains(newTy))
+            {
+                replaceChildren(newTy);
+                replacedTypes.insert(newTy);
+            }
+        }
+        else
+        {
+            if (!ignoreChildren(oldTy))
+                replaceChildren(newTy);
+        }
+    }
     for (auto [oldTp, newTp] : newPacks)
-        if (!ignoreChildren(oldTp))
-            replaceChildren(newTp);
+    {
+        if (FFlag::LuauSubstitutionReentrant)
+        {
+            if (!ignoreChildren(oldTp) && !replacedTypePacks.contains(newTp))
+            {
+                replaceChildren(newTp);
+                replacedTypePacks.insert(newTp);
+            }
+        }
+        else
+        {
+            if (!ignoreChildren(oldTp))
+                replaceChildren(newTp);
+        }
+    }
     TypePackId newTp = replace(tp);
     return newTp;
 }
@@ -385,6 +493,8 @@ TypePackId Substitution::clone(TypePackId tp)
     {
         VariadicTypePack clone;
         clone.ty = vtp->ty;
+        if (FFlag::LuauSubstitutionFixMissingFields)
+            clone.hidden = vtp->hidden;
         return addTypePack(std::move(clone));
     }
     else
@@ -395,6 +505,9 @@ void Substitution::foundDirty(TypeId ty)
 {
     ty = log->follow(ty);
 
+    if (FFlag::LuauSubstitutionReentrant && newTypes.contains(ty))
+            return;
+
     if (isDirty(ty))
         newTypes[ty] = follow(clean(ty));
     else
@@ -405,6 +518,9 @@ void Substitution::foundDirty(TypePackId tp)
 {
     tp = log->follow(tp);
 
+    if (FFlag::LuauSubstitutionReentrant && newPacks.contains(tp))
+            return;
+
     if (isDirty(tp))
         newPacks[tp] = follow(clean(tp));
     else
@@ -446,6 +562,14 @@ void Substitution::replaceChildren(TypeId ty)
 
     if (FunctionTypeVar* ftv = getMutable<FunctionTypeVar>(ty))
     {
+        if (FFlag::LuauSubstitutionFixMissingFields)
+        {
+            for (TypeId& generic : ftv->generics)
+                generic = replace(generic);
+            for (TypePackId& genericPack : ftv->genericPacks)
+                genericPack = replace(genericPack);
+        }
+
         ftv->argTypes = replace(ftv->argTypes);
         ftv->retTypes = replace(ftv->retTypes);
     }
@@ -486,6 +610,25 @@ void Substitution::replaceChildren(TypeId ty)
         for (TypeId& part : ctv->parts)
             part = replace(part);
     }
+    else if (PendingExpansionTypeVar* petv = getMutable<PendingExpansionTypeVar>(ty))
+    {
+        for (TypeId& a : petv->typeArguments)
+            a = replace(a);
+
+        for (TypePackId& a : petv->packArguments)
+            a = replace(a);
+    }
+    else if (ClassTypeVar* ctv = getMutable<ClassTypeVar>(ty); FFlag::LuauClassTypeVarsInSubstitution && ctv)
+    {
+        for (auto& [name, prop] : ctv->props)
+            prop.type = replace(prop.type);
+
+        if (ctv->parent)
+            ctv->parent = replace(*ctv->parent);
+
+        if (ctv->metatable)
+            ctv->metatable = replace(*ctv->metatable);
+    }
 }
 
 void Substitution::replaceChildren(TypePackId tp)

Analysis/src/ToString.cpp

@@ -232,6 +232,11 @@ struct StringifierState
         emit(std::to_string(i).c_str());
     }
 
+    void emit(size_t i)
+    {
+        emit(std::to_string(i).c_str());
+    }
+
     void indent()
     {
         indentation += 4;
@@ -410,6 +415,13 @@ struct TypeVarStringifier
         state.emit("*");
     }
 
+    void operator()(TypeId ty, const PendingExpansionTypeVar& petv)
+    {
+        state.emit("*pending-expansion-");
+        state.emit(petv.index);
+        state.emit("*");
+    }
+
     void operator()(TypeId, const PrimitiveTypeVar& ptv)
     {
         switch (ptv.type)
@@ -1459,6 +1471,12 @@ std::string toString(const Constraint& constraint, ToStringOptions& opts)
             opts.nameMap = std::move(namedStr.nameMap);
             return "@name(" + namedStr.name + ") = " + c.name;
         }
+        else if constexpr (std::is_same_v<T, TypeAliasExpansionConstraint>)
+        {
+            ToStringResult targetStr = toStringDetailed(c.target, opts);
+            opts.nameMap = std::move(targetStr.nameMap);
+            return "expand " + targetStr.name;
+        }
         else
             static_assert(always_false_v<T>, "Non-exhaustive constraint switch");
     };

Analysis/src/TypeAttach.cpp

@@ -99,6 +99,11 @@ public:
         return allocator->alloc<AstTypeReference>(Location(), std::nullopt, AstName("*blocked*"));
     }
 
+    AstType* operator()(const PendingExpansionTypeVar& petv)
+    {
+        return allocator->alloc<AstTypeReference>(Location(), std::nullopt, AstName("*pending-expansion*"));
+    }
+
     AstType* operator()(const ConstrainedTypeVar& ctv)
     {
         AstArray<AstType*> types;

Analysis/src/TypeChecker2.cpp

@@ -67,6 +67,13 @@ struct TypeChecker2 : public AstVisitor
         return follow(*ty);
     }
 
+    TypePackId lookupPackAnnotation(AstTypePack* annotation)
+    {
+        TypePackId* tp = module->astResolvedTypePacks.find(annotation);
+        LUAU_ASSERT(tp);
+        return follow(*tp);
+    }
+
     TypePackId reconstructPack(AstArray<AstExpr*> exprs, TypeArena& arena)
     {
         if (exprs.size == 0)
@@ -363,12 +370,153 @@ struct TypeChecker2 : public AstVisitor
     bool visit(AstTypeReference* ty) override
     {
         Scope* scope = findInnermostScope(ty->location);
+        LUAU_ASSERT(scope);
 
         // TODO: Imported types
-        // TODO: Generic types
-        if (!scope->lookupTypeBinding(ty->name.value))
+
+        std::optional<TypeFun> alias = scope->lookupTypeBinding(ty->name.value);
+
+        if (alias.has_value())
         {
-            reportError(UnknownSymbol{ty->name.value, UnknownSymbol::Context::Type}, ty->location);
+            size_t typesRequired = alias->typeParams.size();
+            size_t packsRequired = alias->typePackParams.size();
+
+            bool hasDefaultTypes = std::any_of(alias->typeParams.begin(), alias->typeParams.end(), [](auto&& el) {
+                return el.defaultValue.has_value();
+            });
+
+            bool hasDefaultPacks = std::any_of(alias->typePackParams.begin(), alias->typePackParams.end(), [](auto&& el) {
+                return el.defaultValue.has_value();
+            });
+
+            if (!ty->hasParameterList)
+            {
+                if ((!alias->typeParams.empty() && !hasDefaultTypes) || (!alias->typePackParams.empty() && !hasDefaultPacks))
+                {
+                    reportError(GenericError{"Type parameter list is required"}, ty->location);
+                }
+            }
+
+            size_t typesProvided = 0;
+            size_t extraTypes = 0;
+            size_t packsProvided = 0;
+
+            for (const AstTypeOrPack& p : ty->parameters)
+            {
+                if (p.type)
+                {
+                    if (packsProvided != 0)
+                    {
+                        reportError(GenericError{"Type parameters must come before type pack parameters"}, ty->location);
+                    }
+
+                    if (typesProvided < typesRequired)
+                    {
+                        typesProvided += 1;
+                    }
+                    else
+                    {
+                        extraTypes += 1;
+                    }
+                }
+                else if (p.typePack)
+                {
+                    TypePackId tp = lookupPackAnnotation(p.typePack);
+
+                    if (typesProvided < typesRequired && size(tp) == 1 && finite(tp) && first(tp))
+                    {
+                        typesProvided += 1;
+                    }
+                    else
+                    {
+                        packsProvided += 1;
+                    }
+                }
+            }
+
+            if (extraTypes != 0 && packsProvided == 0)
+            {
+                packsProvided += 1;
+            }
+
+            for (size_t i = typesProvided; i < typesRequired; ++i)
+            {
+                if (alias->typeParams[i].defaultValue)
+                {
+                    typesProvided += 1;
+                }
+            }
+
+            for (size_t i = packsProvided; i < packsProvided; ++i)
+            {
+                if (alias->typePackParams[i].defaultValue)
+                {
+                    packsProvided += 1;
+                }
+            }
+
+            if (extraTypes == 0 && packsProvided + 1 == packsRequired)
+            {
+                packsProvided += 1;
+            }
+
+            if (typesProvided != typesRequired || packsProvided != packsRequired)
+            {
+                reportError(IncorrectGenericParameterCount{
+                                /* name */ ty->name.value,
+                                /* typeFun */ *alias,
+                                /* actualParameters */ typesProvided,
+                                /* actualPackParameters */ packsProvided,
+                            },
+                    ty->location);
+            }
+        }
+        else
+        {
+            if (scope->lookupTypePackBinding(ty->name.value))
+            {
+                reportError(
+                    SwappedGenericTypeParameter{
+                        ty->name.value,
+                        SwappedGenericTypeParameter::Kind::Type,
+                    },
+                    ty->location);
+            }
+            else
+            {
+                reportError(UnknownSymbol{ty->name.value, UnknownSymbol::Context::Type}, ty->location);
+            }
+        }
+
+        return true;
+    }
+
+    bool visit(AstTypePack*) override
+    {
+        return true;
+    }
+
+    bool visit(AstTypePackGeneric* tp) override
+    {
+        Scope* scope = findInnermostScope(tp->location);
+        LUAU_ASSERT(scope);
+
+        std::optional<TypePackId> alias = scope->lookupTypePackBinding(tp->genericName.value);
+        if (!alias.has_value())
+        {
+            if (scope->lookupTypeBinding(tp->genericName.value))
+            {
+                reportError(
+                    SwappedGenericTypeParameter{
+                        tp->genericName.value,
+                        SwappedGenericTypeParameter::Kind::Pack,
+                    },
+                    tp->location);
+            }
+            else
+            {
+                reportError(UnknownSymbol{tp->genericName.value, UnknownSymbol::Context::Type}, tp->location);
+            }
         }
 
         return true;

Analysis/src/TypeInfer.cpp

@@ -1,6 +1,7 @@
 // This file is part of the Luau programming language and is licensed under MIT License; see LICENSE.txt for details
 #include "Luau/TypeInfer.h"
 
+#include "Luau/ApplyTypeFunction.h"
 #include "Luau/Clone.h"
 #include "Luau/Common.h"
 #include "Luau/Instantiation.h"
@@ -36,11 +37,8 @@ LUAU_FASTFLAGVARIABLE(LuauIndexSilenceErrors, false)
 LUAU_FASTFLAGVARIABLE(LuauLowerBoundsCalculation, false)
 LUAU_FASTFLAGVARIABLE(DebugLuauFreezeDuringUnification, false)
 LUAU_FASTFLAGVARIABLE(LuauSelfCallAutocompleteFix3, false)
-LUAU_FASTFLAGVARIABLE(LuauReduceUnionRecursion, false)
 LUAU_FASTFLAGVARIABLE(LuauReturnAnyInsteadOfICE, false) // Eventually removed as false.
-LUAU_FASTFLAG(LuauNormalizeFlagIsConservative)
 LUAU_FASTFLAGVARIABLE(DebugLuauSharedSelf, false);
-LUAU_FASTFLAGVARIABLE(LuauAlwaysQuantify, false);
 LUAU_FASTFLAGVARIABLE(LuauReportErrorsOnIndexerKeyMismatch, false)
 LUAU_FASTFLAGVARIABLE(LuauUnknownAndNeverType, false)
 LUAU_FASTFLAG(LuauQuantifyConstrained)
@@ -2108,35 +2106,16 @@ std::vector<TypeId> TypeChecker::reduceUnion(const std::vector<TypeId>& types)
 
         if (const UnionTypeVar* utv = get<UnionTypeVar>(t))
         {
-            if (FFlag::LuauReduceUnionRecursion)
+            for (TypeId ty : utv)
             {
-                for (TypeId ty : utv)
-                {
-                    if (FFlag::LuauNormalizeFlagIsConservative)
-                        ty = follow(ty);
-                    if (get<NeverTypeVar>(ty))
-                        continue;
-                    if (get<ErrorTypeVar>(ty) || get<AnyTypeVar>(ty))
-                        return {ty};
+                ty = follow(ty);
+                if (get<NeverTypeVar>(ty))
+                    continue;
+                if (get<ErrorTypeVar>(ty) || get<AnyTypeVar>(ty))
+                    return {ty};
 
-                    if (result.end() == std::find(result.begin(), result.end(), ty))
-                        result.push_back(ty);
-                }
-            }
-            else
-            {
-                std::vector<TypeId> r = reduceUnion(utv->options);
-                for (TypeId ty : r)
-                {
-                    ty = follow(ty);
-                    if (get<NeverTypeVar>(ty))
-                        continue;
-                    if (get<ErrorTypeVar>(ty) || get<AnyTypeVar>(ty))
-                        return {ty};
-
-                    if (std::find(result.begin(), result.end(), ty) == result.end())
-                        result.push_back(ty);
-                }
+                if (result.end() == std::find(result.begin(), result.end(), ty))
+                    result.push_back(ty);
             }
         }
         else if (std::find(result.begin(), result.end(), t) == result.end())
@@ -4770,16 +4749,8 @@ TypeId TypeChecker::quantify(const ScopePtr& scope, TypeId ty, Location location
     {
         const FunctionTypeVar* ftv = get<FunctionTypeVar>(ty);
 
-        if (FFlag::LuauAlwaysQuantify)
-        {
-            if (ftv)
-                Luau::quantify(ty, scope->level);
-        }
-        else
-        {
-            if (ftv && ftv->generics.empty() && ftv->genericPacks.empty())
-                Luau::quantify(ty, scope->level);
-        }
+        if (ftv)
+            Luau::quantify(ty, scope->level);
 
         if (FFlag::LuauLowerBoundsCalculation && ftv)
         {
@@ -5253,7 +5224,7 @@ TypeId TypeChecker::resolveTypeWorker(const ScopePtr& scope, const AstType& anno
         if (notEnoughParameters && hasDefaultParameters)
         {
             // 'applyTypeFunction' is used to substitute default types that reference previous generic types
-            ApplyTypeFunction applyTypeFunction{&currentModule->internalTypes, scope->level};
+            ApplyTypeFunction applyTypeFunction{&currentModule->internalTypes};
 
             for (size_t i = 0; i < typesProvided; ++i)
                 applyTypeFunction.typeArguments[tf->typeParams[i].ty] = typeParams[i];
@@ -5494,65 +5465,13 @@ TypePackId TypeChecker::resolveTypePack(const ScopePtr& scope, const AstTypePack
     return result;
 }
 
-bool ApplyTypeFunction::isDirty(TypeId ty)
-{
-    if (typeArguments.count(ty))
-        return true;
-    else if (const FreeTypeVar* ftv = get<FreeTypeVar>(ty))
-    {
-        if (ftv->forwardedTypeAlias)
-            encounteredForwardedType = true;
-        return false;
-    }
-    else
-        return false;
-}
-
-bool ApplyTypeFunction::isDirty(TypePackId tp)
-{
-    if (typePackArguments.count(tp))
-        return true;
-    else
-        return false;
-}
-
-bool ApplyTypeFunction::ignoreChildren(TypeId ty)
-{
-    if (get<GenericTypeVar>(ty))
-        return true;
-    else
-        return false;
-}
-
-bool ApplyTypeFunction::ignoreChildren(TypePackId tp)
-{
-    if (get<GenericTypePack>(tp))
-        return true;
-    else
-        return false;
-}
-
-TypeId ApplyTypeFunction::clean(TypeId ty)
-{
-    TypeId& arg = typeArguments[ty];
-    LUAU_ASSERT(arg);
-    return arg;
-}
-
-TypePackId ApplyTypeFunction::clean(TypePackId tp)
-{
-    TypePackId& arg = typePackArguments[tp];
-    LUAU_ASSERT(arg);
-    return arg;
-}
-
 TypeId TypeChecker::instantiateTypeFun(const ScopePtr& scope, const TypeFun& tf, const std::vector<TypeId>& typeParams,
     const std::vector<TypePackId>& typePackParams, const Location& location)
 {
     if (tf.typeParams.empty() && tf.typePackParams.empty())
         return tf.type;
 
-    ApplyTypeFunction applyTypeFunction{&currentModule->internalTypes, scope->level};
+    ApplyTypeFunction applyTypeFunction{&currentModule->internalTypes};
 
     for (size_t i = 0; i < tf.typeParams.size(); ++i)
         applyTypeFunction.typeArguments[tf.typeParams[i].ty] = typeParams[i];

Analysis/src/TypeVar.cpp

@@ -445,6 +445,16 @@ BlockedTypeVar::BlockedTypeVar()
 
 int BlockedTypeVar::nextIndex = 0;
 
+PendingExpansionTypeVar::PendingExpansionTypeVar(TypeFun fn, std::vector<TypeId> typeArguments, std::vector<TypePackId> packArguments)
+    : fn(fn)
+    , typeArguments(typeArguments)
+    , packArguments(packArguments)
+    , index(++nextIndex)
+{
+}
+
+size_t PendingExpansionTypeVar::nextIndex = 0;
+
 FunctionTypeVar::FunctionTypeVar(TypePackId argTypes, TypePackId retTypes, std::optional<FunctionDefinition> defn, bool hasSelf)
     : argTypes(argTypes)
     , retTypes(retTypes)
@@ -1412,4 +1422,19 @@ bool hasTag(const Property& prop, const std::string& tagName)
     return hasTag(prop.tags, tagName);
 }
 
+bool TypeFun::operator==(const TypeFun& rhs) const
+{
+    return type == rhs.type && typeParams == rhs.typeParams && typePackParams == rhs.typePackParams;
+}
+
+bool GenericTypeDefinition::operator==(const GenericTypeDefinition& rhs) const
+{
+    return ty == rhs.ty && defaultValue == rhs.defaultValue;
+}
+
+bool GenericTypePackDefinition::operator==(const GenericTypePackDefinition& rhs) const
+{
+    return tp == rhs.tp && defaultValue == rhs.defaultValue;
+}
+
 } // namespace Luau

Ast/include/Luau/Ast.h

@@ -474,16 +474,26 @@ public:
     bool value;
 };
 
+enum class ConstantNumberParseResult
+{
+    Ok,
+    Malformed,
+    BinOverflow,
+    HexOverflow,
+    DoublePrefix,
+};
+
 class AstExprConstantNumber : public AstExpr
 {
 public:
     LUAU_RTTI(AstExprConstantNumber)
 
-    AstExprConstantNumber(const Location& location, double value);
+    AstExprConstantNumber(const Location& location, double value, ConstantNumberParseResult parseResult = ConstantNumberParseResult::Ok);
 
     void visit(AstVisitor* visitor) override;
 
     double value;
+    ConstantNumberParseResult parseResult;
 };
 
 class AstExprConstantString : public AstExpr

Ast/src/Ast.cpp

@@ -50,9 +50,10 @@ void AstExprConstantBool::visit(AstVisitor* visitor)
     visitor->visit(this);
 }
 
-AstExprConstantNumber::AstExprConstantNumber(const Location& location, double value)
+AstExprConstantNumber::AstExprConstantNumber(const Location& location, double value, ConstantNumberParseResult parseResult)
     : AstExpr(ClassIndex(), location)
     , value(value)
+    , parseResult(parseResult)
 {
 }
 

Ast/src/Parser.cpp

@@ -21,7 +21,8 @@ LUAU_DYNAMIC_FASTFLAGVARIABLE(LuaReportParseWrongNamedType, false)
 
 bool lua_telemetry_parsed_named_non_function_type = false;
 
-LUAU_FASTFLAGVARIABLE(LuauErrorParseIntegerIssues, false)
+LUAU_FASTFLAGVARIABLE(LuauErrorDoubleHexPrefix, false)
+LUAU_FASTFLAGVARIABLE(LuauLintParseIntegerIssues, false)
 LUAU_DYNAMIC_FASTFLAGVARIABLE(LuaReportParseIntegerIssues, false)
 
 bool lua_telemetry_parsed_out_of_range_bin_integer = false;
@@ -2032,8 +2033,10 @@ AstExpr* Parser::parseAssertionExpr()
         return expr;
 }
 
-static const char* parseInteger(double& result, const char* data, int base)
+static const char* parseInteger_DEPRECATED(double& result, const char* data, int base)
 {
+    LUAU_ASSERT(!FFlag::LuauLintParseIntegerIssues);
+
     char* end = nullptr;
     unsigned long long value = strtoull(data, &end, base);
 
@@ -2053,9 +2056,6 @@ static const char* parseInteger(double& result, const char* data, int base)
                 else
                     lua_telemetry_parsed_out_of_range_hex_integer = true;
             }
-
-            if (FFlag::LuauErrorParseIntegerIssues)
-                return "Integer number value is out of range";
         }
     }
 
@@ -2063,11 +2063,13 @@ static const char* parseInteger(double& result, const char* data, int base)
     return *end == 0 ? nullptr : "Malformed number";
 }
 
-static const char* parseNumber(double& result, const char* data)
+static const char* parseNumber_DEPRECATED2(double& result, const char* data)
 {
+    LUAU_ASSERT(!FFlag::LuauLintParseIntegerIssues);
+
     // binary literal
     if (data[0] == '0' && (data[1] == 'b' || data[1] == 'B') && data[2])
-        return parseInteger(result, data + 2, 2);
+        return parseInteger_DEPRECATED(result, data + 2, 2);
 
     // hexadecimal literal
     if (data[0] == '0' && (data[1] == 'x' || data[1] == 'X') && data[2])
@@ -2075,10 +2077,7 @@ static const char* parseNumber(double& result, const char* data)
         if (DFFlag::LuaReportParseIntegerIssues && data[2] == '0' && (data[3] == 'x' || data[3] == 'X'))
             lua_telemetry_parsed_double_prefix_hex_integer = true;
 
-        if (FFlag::LuauErrorParseIntegerIssues)
-            return parseInteger(result, data, 16); // keep prefix, it's handled by 'strtoull'
-        else
-            return parseInteger(result, data + 2, 16);
+        return parseInteger_DEPRECATED(result, data + 2, 16);
     }
 
     char* end = nullptr;
@@ -2090,6 +2089,8 @@ static const char* parseNumber(double& result, const char* data)
 
 static bool parseNumber_DEPRECATED(double& result, const char* data)
 {
+    LUAU_ASSERT(!FFlag::LuauLintParseIntegerIssues);
+
     // binary literal
     if (data[0] == '0' && (data[1] == 'b' || data[1] == 'B') && data[2])
     {
@@ -2118,6 +2119,73 @@ static bool parseNumber_DEPRECATED(double& result, const char* data)
     }
 }
 
+static ConstantNumberParseResult parseInteger(double& result, const char* data, int base)
+{
+    LUAU_ASSERT(FFlag::LuauLintParseIntegerIssues);
+    LUAU_ASSERT(base == 2 || base == 16);
+
+    char* end = nullptr;
+    unsigned long long value = strtoull(data, &end, base);
+
+    if (*end != 0)
+        return ConstantNumberParseResult::Malformed;
+
+    result = double(value);
+
+    if (value == ULLONG_MAX && errno == ERANGE)
+    {
+        // 'errno' might have been set before we called 'strtoull', but we don't want the overhead of resetting a TLS variable on each call
+        // so we only reset it when we get a result that might be an out-of-range error and parse again to make sure
+        errno = 0;
+        value = strtoull(data, &end, base);
+
+        if (errno == ERANGE)
+        {
+            if (DFFlag::LuaReportParseIntegerIssues)
+            {
+                if (base == 2)
+                    lua_telemetry_parsed_out_of_range_bin_integer = true;
+                else
+                    lua_telemetry_parsed_out_of_range_hex_integer = true;
+            }
+
+            return base == 2 ? ConstantNumberParseResult::BinOverflow : ConstantNumberParseResult::HexOverflow;
+        }
+    }
+
+    return ConstantNumberParseResult::Ok;
+}
+
+static ConstantNumberParseResult parseNumber(double& result, const char* data)
+{
+    LUAU_ASSERT(FFlag::LuauLintParseIntegerIssues);
+
+    // binary literal
+    if (data[0] == '0' && (data[1] == 'b' || data[1] == 'B') && data[2])
+        return parseInteger(result, data + 2, 2);
+
+    // hexadecimal literal
+    if (data[0] == '0' && (data[1] == 'x' || data[1] == 'X') && data[2])
+    {
+        if (!FFlag::LuauErrorDoubleHexPrefix && data[2] == '0' && (data[3] == 'x' || data[3] == 'X'))
+        {
+            if (DFFlag::LuaReportParseIntegerIssues)
+                lua_telemetry_parsed_double_prefix_hex_integer = true;
+
+            ConstantNumberParseResult parseResult = parseInteger(result, data + 2, 16);
+            return parseResult == ConstantNumberParseResult::Malformed ? parseResult : ConstantNumberParseResult::DoublePrefix;
+        }
+
+        return parseInteger(result, data, 16); // pass in '0x' prefix, it's handled by 'strtoull'
+    }
+
+    char* end = nullptr;
+    double value = strtod(data, &end);
+
+    result = value;
+    return *end == 0 ? ConstantNumberParseResult::Ok : ConstantNumberParseResult::Malformed;
+}
+
 // simpleexp -> NUMBER | STRING | NIL | true | false | ... | constructor | FUNCTION body | primaryexp
 AstExpr* Parser::parseSimpleExpr()
 {
@@ -2158,10 +2226,21 @@ AstExpr* Parser::parseSimpleExpr()
             scratchData.erase(std::remove(scratchData.begin(), scratchData.end(), '_'), scratchData.end());
         }
 
-        if (DFFlag::LuaReportParseIntegerIssues || FFlag::LuauErrorParseIntegerIssues)
+        if (FFlag::LuauLintParseIntegerIssues)
         {
             double value = 0;
-            if (const char* error = parseNumber(value, scratchData.c_str()))
+            ConstantNumberParseResult result = parseNumber(value, scratchData.c_str());
+            nextLexeme();
+
+            if (result == ConstantNumberParseResult::Malformed)
+                return reportExprError(start, {}, "Malformed number");
+
+            return allocator.alloc<AstExprConstantNumber>(start, value, result);
+        }
+        else if (DFFlag::LuaReportParseIntegerIssues)
+        {
+            double value = 0;
+            if (const char* error = parseNumber_DEPRECATED2(value, scratchData.c_str()))
             {
                 nextLexeme();
 

CLI/Ast.cpp

@@ -3,7 +3,7 @@
 
 #include "Luau/Common.h"
 #include "Luau/Ast.h"
-#include "Luau/JsonEncoder.h"
+#include "Luau/AstJsonEncoder.h"
 #include "Luau/Parser.h"
 #include "Luau/ParseOptions.h"
 

CLI/Repl.cpp

@@ -109,8 +109,8 @@ static int lua_loadstring(lua_State* L)
         return 1;
 
     lua_pushnil(L);
-    lua_insert(L, -2); /* put before error message */
-    return 2;          /* return nil plus error message */
+    lua_insert(L, -2); // put before error message
+    return 2;          // return nil plus error message
 }
 
 static int finishrequire(lua_State* L)

Common/include/Luau/Bytecode.h

@@ -37,6 +37,14 @@
 // Note that Luau runtime doesn't provide indefinite bytecode compatibility: support for older versions gets removed over time. As such, bytecode isn't a durable storage format and it's expected
 // that Luau users can recompile bytecode from source on Luau version upgrades if necessary.
 
+// # Bytecode version history
+//
+// Note: due to limitations of the versioning scheme, some bytecode blobs that carry version 2 are using features from version 3. Starting from version 3, version should be sufficient to indicate bytecode compatibility.
+//
+// Version 1: Baseline version for the open-source release. Supported until 0.521.
+// Version 2: Adds Proto::linedefined. Currently supported.
+// Version 3: Adds FORGPREP/JUMPXEQK* and enhances AUX encoding for FORGLOOP. Removes FORGLOOP_NEXT/INEXT and JUMPIFEQK/JUMPIFNOTEQK. Currently supported.
+
 // Bytecode opcode, part of the instruction header
 enum LuauOpcode
 {
@@ -367,6 +375,20 @@ enum LuauOpcode
     // D: jump offset (-32768..32767)
     LOP_FORGPREP,
 
+    // JUMPXEQKNIL, JUMPXEQKB: jumps to target offset if the comparison with constant is true (or false, see AUX)
+    // A: source register 1
+    // D: jump offset (-32768..32767; 0 means "next instruction" aka "don't jump")
+    // AUX: constant value (for boolean) in low bit, NOT flag (that flips comparison result) in high bit
+    LOP_JUMPXEQKNIL,
+    LOP_JUMPXEQKB,
+
+    // JUMPXEQKN, JUMPXEQKS: jumps to target offset if the comparison with constant is true (or false, see AUX)
+    // A: source register 1
+    // D: jump offset (-32768..32767; 0 means "next instruction" aka "don't jump")
+    // AUX: constant table index in low 24 bits, NOT flag (that flips comparison result) in high bit
+    LOP_JUMPXEQKN,
+    LOP_JUMPXEQKS,
+
     // Enum entry for number of opcodes, not a valid opcode by itself!
     LOP__COUNT
 };
@@ -391,7 +413,7 @@ enum LuauBytecodeTag
 {
     // Bytecode version; runtime supports [MIN, MAX], compiler emits TARGET by default but may emit a higher version when flags are enabled
     LBC_VERSION_MIN = 2,
-    LBC_VERSION_MAX = 2,
+    LBC_VERSION_MAX = 3,
     LBC_VERSION_TARGET = 2,
     // Types of constant table entries
     LBC_CONSTANT_NIL = 0,

Common/include/Luau/Common.h

@@ -20,12 +20,6 @@
 #define LUAU_DEBUGBREAK() __builtin_trap()
 #endif
 
-
-
-
-
-
-
 namespace Luau
 {
 
@@ -67,16 +61,13 @@ struct FValue
     const char* name;
     FValue* next;
 
-    FValue(const char* name, T def, bool dynamic, void (*reg)(const char*, T*, bool) = nullptr)
+    FValue(const char* name, T def, bool dynamic)
         : value(def)
         , dynamic(dynamic)
         , name(name)
         , next(list)
     {
         list = this;
-
-        if (reg)
-            reg(name, &value, dynamic);
     }
 
     operator T() const
@@ -98,7 +89,7 @@ FValue<T>* FValue<T>::list = nullptr;
 #define LUAU_FASTFLAGVARIABLE(flag, def) \
     namespace FFlag \
     { \
-    Luau::FValue<bool> flag(#flag, def, false, nullptr); \
+    Luau::FValue<bool> flag(#flag, def, false); \
     }
 #define LUAU_FASTINT(flag) \
     namespace FInt \
@@ -108,7 +99,7 @@ FValue<T>* FValue<T>::list = nullptr;
 #define LUAU_FASTINTVARIABLE(flag, def) \
     namespace FInt \
     { \
-    Luau::FValue<int> flag(#flag, def, false, nullptr); \
+    Luau::FValue<int> flag(#flag, def, false); \
     }
 
 #define LUAU_DYNAMIC_FASTFLAG(flag) \
@@ -119,7 +110,7 @@ FValue<T>* FValue<T>::list = nullptr;
 #define LUAU_DYNAMIC_FASTFLAGVARIABLE(flag, def) \
     namespace DFFlag \
     { \
-    Luau::FValue<bool> flag(#flag, def, true, nullptr); \
+    Luau::FValue<bool> flag(#flag, def, true); \
     }
 #define LUAU_DYNAMIC_FASTINT(flag) \
     namespace DFInt \
@@ -129,5 +120,5 @@ FValue<T>* FValue<T>::list = nullptr;
 #define LUAU_DYNAMIC_FASTINTVARIABLE(flag, def) \
     namespace DFInt \
     { \
-    Luau::FValue<int> flag(#flag, def, true, nullptr); \
+    Luau::FValue<int> flag(#flag, def, true); \
     }

Common/include/Luau/ExperimentalFlags.h

@@ -10,17 +10,16 @@ inline bool isFlagExperimental(const char* flag)
 {
     // Flags in this list are disabled by default in various command-line tools. They may have behavior that is not fully final,
     // or critical bugs that are found after the code has been submitted.
-    static const char* kList[] =
-    {
+    static const char* kList[] = {
         "LuauLowerBoundsCalculation",
         nullptr, // makes sure we always have at least one entry
     };
 
-    for (const char* item: kList)
+    for (const char* item : kList)
         if (item && strcmp(item, flag) == 0)
             return true;
 
     return false;
 }
 
-}
+} // namespace Luau

Compiler/include/luacode.h

@@ -3,7 +3,7 @@
 
 #include <stddef.h>
 
-/* Can be used to reconfigure visibility/exports for public APIs */
+// Can be used to reconfigure visibility/exports for public APIs
 #ifndef LUACODE_API
 #define LUACODE_API extern
 #endif
@@ -35,5 +35,5 @@ struct lua_CompileOptions
     const char** mutableGlobals;
 };
 
-/* compile source to bytecode; when source compilation fails, the resulting bytecode contains the encoded error. use free() to destroy */
+// compile source to bytecode; when source compilation fails, the resulting bytecode contains the encoded error. use free() to destroy
 LUACODE_API char* luau_compile(const char* source, size_t size, lua_CompileOptions* options, size_t* outsize);

Compiler/src/Builtins.cpp

@@ -4,8 +4,6 @@
 #include "Luau/Bytecode.h"
 #include "Luau/Compiler.h"
 
-LUAU_FASTFLAGVARIABLE(LuauCompileRawlen, false)
-
 namespace Luau
 {
 namespace Compile
@@ -57,7 +55,7 @@ static int getBuiltinFunctionId(const Builtin& builtin, const CompileOptions& op
         return LBF_RAWGET;
     if (builtin.isGlobal("rawequal"))
         return LBF_RAWEQUAL;
-    if (FFlag::LuauCompileRawlen && builtin.isGlobal("rawlen"))
+    if (builtin.isGlobal("rawlen"))
         return LBF_RAWLEN;
 
     if (builtin.isGlobal("unpack"))

Compiler/src/BytecodeBuilder.cpp

@@ -6,6 +6,8 @@
 #include <algorithm>
 #include <string.h>
 
+LUAU_FASTFLAGVARIABLE(LuauCompileBytecodeV3, false)
+
 namespace Luau
 {
 
@@ -77,6 +79,10 @@ static int getOpLength(LuauOpcode op)
     case LOP_JUMPIFNOTEQK:
     case LOP_FASTCALL2:
     case LOP_FASTCALL2K:
+    case LOP_JUMPXEQKNIL:
+    case LOP_JUMPXEQKB:
+    case LOP_JUMPXEQKN:
+    case LOP_JUMPXEQKS:
         return 2;
 
     default:
@@ -108,6 +114,10 @@ inline bool isJumpD(LuauOpcode op)
     case LOP_JUMPBACK:
     case LOP_JUMPIFEQK:
     case LOP_JUMPIFNOTEQK:
+    case LOP_JUMPXEQKNIL:
+    case LOP_JUMPXEQKB:
+    case LOP_JUMPXEQKN:
+    case LOP_JUMPXEQKS:
         return true;
 
     default:
@@ -1069,6 +1079,9 @@ std::string BytecodeBuilder::getError(const std::string& message)
 
 uint8_t BytecodeBuilder::getVersion()
 {
+    if (FFlag::LuauCompileBytecodeV3)
+        return 3;
+
     // This function usually returns LBC_VERSION_TARGET but may sometimes return a higher number (within LBC_VERSION_MIN/MAX) under fast flags
     return LBC_VERSION_TARGET;
 }
@@ -1246,6 +1259,24 @@ void BytecodeBuilder::validate() const
             VJUMP(LUAU_INSN_D(insn));
             break;
 
+        case LOP_JUMPXEQKNIL:
+        case LOP_JUMPXEQKB:
+            VREG(LUAU_INSN_A(insn));
+            VJUMP(LUAU_INSN_D(insn));
+            break;
+
+        case LOP_JUMPXEQKN:
+            VREG(LUAU_INSN_A(insn));
+            VCONST(insns[i + 1] & 0xffffff, Number);
+            VJUMP(LUAU_INSN_D(insn));
+            break;
+
+        case LOP_JUMPXEQKS:
+            VREG(LUAU_INSN_A(insn));
+            VCONST(insns[i + 1] & 0xffffff, String);
+            VJUMP(LUAU_INSN_D(insn));
+            break;
+
         case LOP_ADD:
         case LOP_SUB:
         case LOP_MUL:
@@ -1779,6 +1810,26 @@ void BytecodeBuilder::dumpInstruction(const uint32_t* code, std::string& result,
         formatAppend(result, "JUMPIFNOTEQK R%d K%d L%d\n", LUAU_INSN_A(insn), *code++, targetLabel);
         break;
 
+    case LOP_JUMPXEQKNIL:
+        formatAppend(result, "JUMPXEQKNIL R%d L%d%s\n", LUAU_INSN_A(insn), targetLabel, *code >> 31 ? " NOT" : "");
+        code++;
+        break;
+
+    case LOP_JUMPXEQKB:
+        formatAppend(result, "JUMPXEQKB R%d %d L%d%s\n", LUAU_INSN_A(insn), *code & 1, targetLabel, *code >> 31 ? " NOT" : "");
+        code++;
+        break;
+
+    case LOP_JUMPXEQKN:
+        formatAppend(result, "JUMPXEQKN R%d K%d L%d%s\n", LUAU_INSN_A(insn), *code & 0xffffff, targetLabel, *code >> 31 ? " NOT" : "");
+        code++;
+        break;
+
+    case LOP_JUMPXEQKS:
+        formatAppend(result, "JUMPXEQKS R%d K%d L%d%s\n", LUAU_INSN_A(insn), *code & 0xffffff, targetLabel, *code >> 31 ? " NOT" : "");
+        code++;
+        break;
+
     default:
         LUAU_ASSERT(!"Unsupported opcode");
     }

Compiler/src/Compiler.cpp

@@ -26,6 +26,7 @@ LUAU_FASTINTVARIABLE(LuauCompileInlineDepth, 5)
 LUAU_FASTFLAGVARIABLE(LuauCompileNoIpairs, false)
 
 LUAU_FASTFLAGVARIABLE(LuauCompileFreeReassign, false)
+LUAU_FASTFLAGVARIABLE(LuauCompileXEQ, false)
 
 namespace Luau
 {
@@ -1008,9 +1009,8 @@ struct Compiler
     size_t compileCompareJump(AstExprBinary* expr, bool not_ = false)
     {
         RegScope rs(this);
-        LuauOpcode opc = getJumpOpCompare(expr->op, not_);
 
-        bool isEq = (opc == LOP_JUMPIFEQ || opc == LOP_JUMPIFNOTEQ);
+        bool isEq = (expr->op == AstExprBinary::CompareEq || expr->op == AstExprBinary::CompareNe);
         AstExpr* left = expr->left;
         AstExpr* right = expr->right;
 
@@ -1022,36 +1022,112 @@ struct Compiler
                 std::swap(left, right);
         }
 
-        uint8_t rl = compileExprAuto(left, rs);
-        int32_t rr = -1;
-
-        if (isEq && operandIsConstant)
+        if (FFlag::LuauCompileXEQ)
         {
-            if (opc == LOP_JUMPIFEQ)
-                opc = LOP_JUMPIFEQK;
-            else if (opc == LOP_JUMPIFNOTEQ)
-                opc = LOP_JUMPIFNOTEQK;
+            uint8_t rl = compileExprAuto(left, rs);
 
-            rr = getConstantIndex(right);
-            LUAU_ASSERT(rr >= 0);
-        }
-        else
-            rr = compileExprAuto(right, rs);
+            if (isEq && operandIsConstant)
+            {
+                const Constant* cv = constants.find(right);
+                LUAU_ASSERT(cv && cv->type != Constant::Type_Unknown);
 
-        size_t jumpLabel = bytecode.emitLabel();
+                LuauOpcode opc = LOP_NOP;
+                int32_t cid = -1;
+                uint32_t flip = (expr->op == AstExprBinary::CompareEq) == not_ ? 0x80000000 : 0;
 
-        if (expr->op == AstExprBinary::CompareGt || expr->op == AstExprBinary::CompareGe)
-        {
-            bytecode.emitAD(opc, uint8_t(rr), 0);
-            bytecode.emitAux(rl);
+                switch (cv->type)
+                {
+                case Constant::Type_Nil:
+                    opc = LOP_JUMPXEQKNIL;
+                    cid = 0;
+                    break;
+
+                case Constant::Type_Boolean:
+                    opc = LOP_JUMPXEQKB;
+                    cid = cv->valueBoolean;
+                    break;
+
+                case Constant::Type_Number:
+                    opc = LOP_JUMPXEQKN;
+                    cid = getConstantIndex(right);
+                    break;
+
+                case Constant::Type_String:
+                    opc = LOP_JUMPXEQKS;
+                    cid = getConstantIndex(right);
+                    break;
+
+                default:
+                    LUAU_ASSERT(!"Unexpected constant type");
+                }
+
+                if (cid < 0)
+                    CompileError::raise(expr->location, "Exceeded constant limit; simplify the code to compile");
+
+                size_t jumpLabel = bytecode.emitLabel();
+
+                bytecode.emitAD(opc, rl, 0);
+                bytecode.emitAux(cid | flip);
+
+                return jumpLabel;
+            }
+            else
+            {
+                LuauOpcode opc = getJumpOpCompare(expr->op, not_);
+
+                uint8_t rr = compileExprAuto(right, rs);
+
+                size_t jumpLabel = bytecode.emitLabel();
+
+                if (expr->op == AstExprBinary::CompareGt || expr->op == AstExprBinary::CompareGe)
+                {
+                    bytecode.emitAD(opc, rr, 0);
+                    bytecode.emitAux(rl);
+                }
+                else
+                {
+                    bytecode.emitAD(opc, rl, 0);
+                    bytecode.emitAux(rr);
+                }
+
+                return jumpLabel;
+            }
         }
         else
         {
-            bytecode.emitAD(opc, rl, 0);
-            bytecode.emitAux(rr);
-        }
+            LuauOpcode opc = getJumpOpCompare(expr->op, not_);
 
-        return jumpLabel;
+            uint8_t rl = compileExprAuto(left, rs);
+            int32_t rr = -1;
+
+            if (isEq && operandIsConstant)
+            {
+                if (opc == LOP_JUMPIFEQ)
+                    opc = LOP_JUMPIFEQK;
+                else if (opc == LOP_JUMPIFNOTEQ)
+                    opc = LOP_JUMPIFNOTEQK;
+
+                rr = getConstantIndex(right);
+                LUAU_ASSERT(rr >= 0);
+            }
+            else
+                rr = compileExprAuto(right, rs);
+
+            size_t jumpLabel = bytecode.emitLabel();
+
+            if (expr->op == AstExprBinary::CompareGt || expr->op == AstExprBinary::CompareGe)
+            {
+                bytecode.emitAD(opc, uint8_t(rr), 0);
+                bytecode.emitAux(rl);
+            }
+            else
+            {
+                bytecode.emitAD(opc, rl, 0);
+                bytecode.emitAux(rr);
+            }
+
+            return jumpLabel;
+        }
     }
 
     int32_t getConstantNumber(AstExpr* node)

Makefile

@@ -55,6 +55,7 @@ ifneq ($(opt),)
 endif
 
 OBJECTS=$(AST_OBJECTS) $(COMPILER_OBJECTS) $(ANALYSIS_OBJECTS) $(CODEGEN_OBJECTS) $(VM_OBJECTS) $(ISOCLINE_OBJECTS) $(TESTS_OBJECTS) $(CLI_OBJECTS) $(FUZZ_OBJECTS)
+EXECUTABLE_ALIASES = luau luau-analyze luau-tests
 
 # common flags
 CXXFLAGS=-g -Wall
@@ -121,14 +122,14 @@ fuzz-proto fuzz-prototest: LDFLAGS+=build/libprotobuf-mutator/src/libfuzzer/libp
 
 all: $(REPL_CLI_TARGET) $(ANALYZE_CLI_TARGET) $(TESTS_TARGET) aliases
 
-aliases: luau luau-analyze
+aliases: $(EXECUTABLE_ALIASES)
 
 test: $(TESTS_TARGET)
 	$(TESTS_TARGET) $(TESTS_ARGS)
 
 clean:
 	rm -rf $(BUILD)
-	rm -rf luau luau-analyze
+	rm -rf $(EXECUTABLE_ALIASES)
 
 coverage: $(TESTS_TARGET)
 	$(TESTS_TARGET) --fflags=true
@@ -154,6 +155,9 @@ luau: $(REPL_CLI_TARGET)
 luau-analyze: $(ANALYZE_CLI_TARGET)
 	ln -fs $^ $@
 
+luau-tests: $(TESTS_TARGET)
+	ln -fs $^ $@
+
 # executable targets
 $(TESTS_TARGET): $(TESTS_OBJECTS) $(ANALYSIS_TARGET) $(COMPILER_TARGET) $(AST_TARGET) $(CODEGEN_TARGET) $(VM_TARGET) $(ISOCLINE_TARGET)
 $(REPL_CLI_TARGET): $(REPL_CLI_OBJECTS) $(COMPILER_TARGET) $(AST_TARGET) $(VM_TARGET) $(ISOCLINE_TARGET)

Sources.cmake

@@ -66,6 +66,8 @@ target_sources(Luau.CodeGen PRIVATE
 
 # Luau.Analysis Sources
 target_sources(Luau.Analysis PRIVATE
+    Analysis/include/Luau/ApplyTypeFunction.h
+    Analysis/include/Luau/AstJsonEncoder.h
     Analysis/include/Luau/AstQuery.h
     Analysis/include/Luau/Autocomplete.h
     Analysis/include/Luau/BuiltinDefinitions.h
@@ -81,7 +83,7 @@ target_sources(Luau.Analysis PRIVATE
     Analysis/include/Luau/Frontend.h
     Analysis/include/Luau/Instantiation.h
     Analysis/include/Luau/IostreamHelpers.h
-    Analysis/include/Luau/JsonEncoder.h
+    Analysis/include/Luau/JsonEmitter.h
     Analysis/include/Luau/Linter.h
     Analysis/include/Luau/LValue.h
     Analysis/include/Luau/Module.h
@@ -113,6 +115,8 @@ target_sources(Luau.Analysis PRIVATE
     Analysis/include/Luau/Variant.h
     Analysis/include/Luau/VisitTypeVar.h
 
+    Analysis/src/ApplyTypeFunction.cpp
+    Analysis/src/AstJsonEncoder.cpp
     Analysis/src/AstQuery.cpp
     Analysis/src/Autocomplete.cpp
     Analysis/src/BuiltinDefinitions.cpp
@@ -126,7 +130,7 @@ target_sources(Luau.Analysis PRIVATE
     Analysis/src/Frontend.cpp
     Analysis/src/Instantiation.cpp
     Analysis/src/IostreamHelpers.cpp
-    Analysis/src/JsonEncoder.cpp
+    Analysis/src/JsonEmitter.cpp
     Analysis/src/Linter.cpp
     Analysis/src/LValue.cpp
     Analysis/src/Module.cpp
@@ -255,6 +259,7 @@ if(TARGET Luau.UnitTest)
         tests/ScopedFlags.h
         tests/Fixture.cpp
         tests/AssemblyBuilderX64.test.cpp
+        tests/AstJsonEncoder.test.cpp
         tests/AstQuery.test.cpp
         tests/AstVisitor.test.cpp
         tests/Autocomplete.test.cpp
@@ -266,7 +271,7 @@ if(TARGET Luau.UnitTest)
         tests/CostModel.test.cpp
         tests/Error.test.cpp
         tests/Frontend.test.cpp
-        tests/JsonEncoder.test.cpp
+        tests/JsonEmitter.test.cpp
         tests/Lexer.test.cpp
         tests/Linter.test.cpp
         tests/LValue.test.cpp

VM/include/lua.h

@@ -11,7 +11,7 @@
 
 
 
-/* option for multiple returns in `lua_pcall' and `lua_call' */
+// option for multiple returns in `lua_pcall' and `lua_call'
 #define LUA_MULTRET (-1)
 
 /*
@@ -23,7 +23,7 @@
 #define lua_upvalueindex(i) (LUA_GLOBALSINDEX - (i))
 #define lua_ispseudo(i) ((i) <= LUA_REGISTRYINDEX)
 
-/* thread status; 0 is OK */
+// thread status; 0 is OK
 enum lua_Status
 {
     LUA_OK = 0,
@@ -32,7 +32,7 @@ enum lua_Status
     LUA_ERRSYNTAX,
     LUA_ERRMEM,
     LUA_ERRERR,
-    LUA_BREAK, /* yielded for a debug breakpoint */
+    LUA_BREAK, // yielded for a debug breakpoint
 };
 
 typedef struct lua_State lua_State;
@@ -46,7 +46,7 @@ typedef int (*lua_Continuation)(lua_State* L, int status);
 
 typedef void* (*lua_Alloc)(void* ud, void* ptr, size_t osize, size_t nsize);
 
-/* non-return type */
+// non-return type
 #define l_noret void LUA_NORETURN
 
 /*
@@ -61,15 +61,15 @@ typedef void* (*lua_Alloc)(void* ud, void* ptr, size_t osize, size_t nsize);
 // clang-format off
 enum lua_Type
 {
-    LUA_TNIL = 0,     /* must be 0 due to lua_isnoneornil */
-    LUA_TBOOLEAN = 1, /* must be 1 due to l_isfalse */
+    LUA_TNIL = 0,     // must be 0 due to lua_isnoneornil
+    LUA_TBOOLEAN = 1, // must be 1 due to l_isfalse
 
 
     LUA_TLIGHTUSERDATA,
     LUA_TNUMBER,
     LUA_TVECTOR,
 
-    LUA_TSTRING, /* all types above this must be value types, all types below this must be GC types - see iscollectable */
+    LUA_TSTRING, // all types above this must be value types, all types below this must be GC types - see iscollectable
 
 
     LUA_TTABLE,
@@ -77,23 +77,23 @@ enum lua_Type
     LUA_TUSERDATA,
     LUA_TTHREAD,
 
-    /* values below this line are used in GCObject tags but may never show up in TValue type tags */
+    // values below this line are used in GCObject tags but may never show up in TValue type tags
     LUA_TPROTO,
     LUA_TUPVAL,
     LUA_TDEADKEY,
 
-    /* the count of TValue type tags */
+    // the count of TValue type tags
     LUA_T_COUNT = LUA_TPROTO
 };
 // clang-format on
 
-/* type of numbers in Luau */
+// type of numbers in Luau
 typedef double lua_Number;
 
-/* type for integer functions */
+// type for integer functions
 typedef int lua_Integer;
 
-/* unsigned integer type */
+// unsigned integer type
 typedef unsigned lua_Unsigned;
 
 /*
@@ -117,7 +117,7 @@ LUA_API void lua_remove(lua_State* L, int idx);
 LUA_API void lua_insert(lua_State* L, int idx);
 LUA_API void lua_replace(lua_State* L, int idx);
 LUA_API int lua_checkstack(lua_State* L, int sz);
-LUA_API void lua_rawcheckstack(lua_State* L, int sz); /* allows for unlimited stack frames */
+LUA_API void lua_rawcheckstack(lua_State* L, int sz); // allows for unlimited stack frames
 
 LUA_API void lua_xmove(lua_State* from, lua_State* to, int n);
 LUA_API void lua_xpush(lua_State* from, lua_State* to, int idx);
@@ -231,18 +231,18 @@ LUA_API void lua_setthreaddata(lua_State* L, void* data);
 
 enum lua_GCOp
 {
-    /* stop and resume incremental garbage collection */
+    // stop and resume incremental garbage collection
     LUA_GCSTOP,
     LUA_GCRESTART,
 
-    /* run a full GC cycle; not recommended for latency sensitive applications */
+    // run a full GC cycle; not recommended for latency sensitive applications
     LUA_GCCOLLECT,
 
-    /* return the heap size in KB and the remainder in bytes */
+    // return the heap size in KB and the remainder in bytes
     LUA_GCCOUNT,
     LUA_GCCOUNTB,
 
-    /* return 1 if GC is active (not stopped); note that GC may not be actively collecting even if it's running */
+    // return 1 if GC is active (not stopped); note that GC may not be actively collecting even if it's running
     LUA_GCISRUNNING,
 
     /*
@@ -359,9 +359,9 @@ LUA_API void lua_unref(lua_State* L, int ref);
 ** =======================================================================
 */
 
-typedef struct lua_Debug lua_Debug; /* activation record */
+typedef struct lua_Debug lua_Debug; // activation record
 
-/* Functions to be called by the debugger in specific events */
+// Functions to be called by the debugger in specific events
 typedef void (*lua_Hook)(lua_State* L, lua_Debug* ar);
 
 LUA_API int lua_stackdepth(lua_State* L);
@@ -379,24 +379,24 @@ typedef void (*lua_Coverage)(void* context, const char* function, int linedefine
 
 LUA_API void lua_getcoverage(lua_State* L, int funcindex, void* context, lua_Coverage callback);
 
-/* Warning: this function is not thread-safe since it stores the result in a shared global array! Only use for debugging. */
+// Warning: this function is not thread-safe since it stores the result in a shared global array! Only use for debugging.
 LUA_API const char* lua_debugtrace(lua_State* L);
 
 struct lua_Debug
 {
-    const char* name;           /* (n) */
-    const char* what;           /* (s) `Lua', `C', `main', `tail' */
-    const char* source;         /* (s) */
-    int linedefined;            /* (s) */
-    int currentline;            /* (l) */
-    unsigned char nupvals;      /* (u) number of upvalues */
-    unsigned char nparams;      /* (a) number of parameters */
-    char isvararg;              /* (a) */
-    char short_src[LUA_IDSIZE]; /* (s) */
-    void* userdata;             /* only valid in luau_callhook */
+    const char* name;           // (n)
+    const char* what;           // (s) `Lua', `C', `main', `tail'
+    const char* source;         // (s)
+    int linedefined;            // (s)
+    int currentline;            // (l)
+    unsigned char nupvals;      // (u) number of upvalues
+    unsigned char nparams;      // (a) number of parameters
+    char isvararg;              // (a)
+    char short_src[LUA_IDSIZE]; // (s)
+    void* userdata;             // only valid in luau_callhook
 };
 
-/* }====================================================================== */
+// }======================================================================
 
 /* Callbacks that can be used to reconfigure behavior of the VM dynamically.
  * These are shared between all coroutines.
@@ -405,18 +405,18 @@ struct lua_Debug
  * can only be changed when the VM is not running any code */
 struct lua_Callbacks
 {
-    void* userdata; /* arbitrary userdata pointer that is never overwritten by Luau */
+    void* userdata; // arbitrary userdata pointer that is never overwritten by Luau
 
-    void (*interrupt)(lua_State* L, int gc);  /* gets called at safepoints (loop back edges, call/ret, gc) if set */
-    void (*panic)(lua_State* L, int errcode); /* gets called when an unprotected error is raised (if longjmp is used) */
+    void (*interrupt)(lua_State* L, int gc);  // gets called at safepoints (loop back edges, call/ret, gc) if set
+    void (*panic)(lua_State* L, int errcode); // gets called when an unprotected error is raised (if longjmp is used)
 
-    void (*userthread)(lua_State* LP, lua_State* L); /* gets called when L is created (LP == parent) or destroyed (LP == NULL) */
-    int16_t (*useratom)(const char* s, size_t l);    /* gets called when a string is created; returned atom can be retrieved via tostringatom */
+    void (*userthread)(lua_State* LP, lua_State* L); // gets called when L is created (LP == parent) or destroyed (LP == NULL)
+    int16_t (*useratom)(const char* s, size_t l);    // gets called when a string is created; returned atom can be retrieved via tostringatom
 
-    void (*debugbreak)(lua_State* L, lua_Debug* ar);     /* gets called when BREAK instruction is encountered */
-    void (*debugstep)(lua_State* L, lua_Debug* ar);      /* gets called after each instruction in single step mode */
-    void (*debuginterrupt)(lua_State* L, lua_Debug* ar); /* gets called when thread execution is interrupted by break in another thread */
-    void (*debugprotectederror)(lua_State* L);           /* gets called when protected call results in an error */
+    void (*debugbreak)(lua_State* L, lua_Debug* ar);     // gets called when BREAK instruction is encountered
+    void (*debugstep)(lua_State* L, lua_Debug* ar);      // gets called after each instruction in single step mode
+    void (*debuginterrupt)(lua_State* L, lua_Debug* ar); // gets called when thread execution is interrupted by break in another thread
+    void (*debugprotectederror)(lua_State* L);           // gets called when protected call results in an error
 };
 typedef struct lua_Callbacks lua_Callbacks;
 

VM/include/luaconf.h

@@ -33,14 +33,14 @@
 #define LUA_NORETURN __attribute__((__noreturn__))
 #endif
 
-/* Can be used to reconfigure visibility/exports for public APIs */
+// Can be used to reconfigure visibility/exports for public APIs
 #ifndef LUA_API
 #define LUA_API extern
 #endif
 
 #define LUALIB_API LUA_API
 
-/* Can be used to reconfigure visibility for internal APIs */
+// Can be used to reconfigure visibility for internal APIs
 #if defined(__GNUC__)
 #define LUAI_FUNC __attribute__((visibility("hidden"))) extern
 #define LUAI_DATA LUAI_FUNC
@@ -49,67 +49,67 @@
 #define LUAI_DATA extern
 #endif
 
-/* Can be used to reconfigure internal error handling to use longjmp instead of C++ EH */
+// Can be used to reconfigure internal error handling to use longjmp instead of C++ EH
 #ifndef LUA_USE_LONGJMP
 #define LUA_USE_LONGJMP 0
 #endif
 
-/* LUA_IDSIZE gives the maximum size for the description of the source */
+// LUA_IDSIZE gives the maximum size for the description of the source
 #ifndef LUA_IDSIZE
 #define LUA_IDSIZE 256
 #endif
 
-/* LUA_MINSTACK is the guaranteed number of Lua stack slots available to a C function */
+// LUA_MINSTACK is the guaranteed number of Lua stack slots available to a C function
 #ifndef LUA_MINSTACK
 #define LUA_MINSTACK 20
 #endif
 
-/* LUAI_MAXCSTACK limits the number of Lua stack slots that a C function can use */
+// LUAI_MAXCSTACK limits the number of Lua stack slots that a C function can use
 #ifndef LUAI_MAXCSTACK
 #define LUAI_MAXCSTACK 8000
 #endif
 
-/* LUAI_MAXCALLS limits the number of nested calls */
+// LUAI_MAXCALLS limits the number of nested calls
 #ifndef LUAI_MAXCALLS
 #define LUAI_MAXCALLS 20000
 #endif
 
-/* LUAI_MAXCCALLS is the maximum depth for nested C calls; this limit depends on native stack size */
+// LUAI_MAXCCALLS is the maximum depth for nested C calls; this limit depends on native stack size
 #ifndef LUAI_MAXCCALLS
 #define LUAI_MAXCCALLS 200
 #endif
 
-/* buffer size used for on-stack string operations; this limit depends on native stack size */
+// buffer size used for on-stack string operations; this limit depends on native stack size
 #ifndef LUA_BUFFERSIZE
 #define LUA_BUFFERSIZE 512
 #endif
 
-/* number of valid Lua userdata tags */
+// number of valid Lua userdata tags
 #ifndef LUA_UTAG_LIMIT
 #define LUA_UTAG_LIMIT 128
 #endif
 
-/* upper bound for number of size classes used by page allocator */
+// upper bound for number of size classes used by page allocator
 #ifndef LUA_SIZECLASSES
 #define LUA_SIZECLASSES 32
 #endif
 
-/* available number of separate memory categories */
+// available number of separate memory categories
 #ifndef LUA_MEMORY_CATEGORIES
 #define LUA_MEMORY_CATEGORIES 256
 #endif
 
-/* minimum size for the string table (must be power of 2) */
+// minimum size for the string table (must be power of 2)
 #ifndef LUA_MINSTRTABSIZE
 #define LUA_MINSTRTABSIZE 32
 #endif
 
-/* maximum number of captures supported by pattern matching */
+// maximum number of captures supported by pattern matching
 #ifndef LUA_MAXCAPTURES
 #define LUA_MAXCAPTURES 32
 #endif
 
-/* }================================================================== */
+// }==================================================================
 
 /*
 @@ LUAI_USER_ALIGNMENT_T is a type that requires maximum alignment.
@@ -126,6 +126,6 @@
         long l; \
     }
 
-#define LUA_VECTOR_SIZE 3 /* must be 3 or 4 */
+#define LUA_VECTOR_SIZE 3 // must be 3 or 4
 
 #define LUA_EXTRA_SIZE LUA_VECTOR_SIZE - 2

VM/include/lualib.h

@@ -72,7 +72,7 @@ LUALIB_API const char* luaL_typename(lua_State* L, int idx);
 
 #define luaL_opt(L, f, n, d) (lua_isnoneornil(L, (n)) ? (d) : f(L, (n)))
 
-/* generic buffer manipulation */
+// generic buffer manipulation
 
 struct luaL_Buffer
 {
@@ -102,7 +102,7 @@ LUALIB_API void luaL_addvalue(luaL_Buffer* B);
 LUALIB_API void luaL_pushresult(luaL_Buffer* B);
 LUALIB_API void luaL_pushresultsize(luaL_Buffer* B, size_t size);
 
-/* builtin libraries */
+// builtin libraries
 LUALIB_API int luaopen_base(lua_State* L);
 
 #define LUA_COLIBNAME "coroutine"
@@ -129,9 +129,9 @@ LUALIB_API int luaopen_math(lua_State* L);
 #define LUA_DBLIBNAME "debug"
 LUALIB_API int luaopen_debug(lua_State* L);
 
-/* open all builtin libraries */
+// open all builtin libraries
 LUALIB_API void luaL_openlibs(lua_State* L);
 
-/* sandbox libraries and globals */
+// sandbox libraries and globals
 LUALIB_API void luaL_sandbox(lua_State* L);
 LUALIB_API void luaL_sandboxthread(lua_State* L);

VM/src/lapi.cpp

@@ -59,8 +59,8 @@ const char* luau_ident = "$Luau: Copyright (C) 2019-2022 Roblox Corporation $\n"
 
 static Table* getcurrenv(lua_State* L)
 {
-    if (L->ci == L->base_ci) /* no enclosing function? */
-        return L->gt;        /* use global table as environment */
+    if (L->ci == L->base_ci) // no enclosing function?
+        return L->gt;        // use global table as environment
     else
         return curr_func(L)->env;
 }
@@ -69,7 +69,7 @@ static LUAU_NOINLINE TValue* pseudo2addr(lua_State* L, int idx)
 {
     api_check(L, lua_ispseudo(idx));
     switch (idx)
-    { /* pseudo-indices */
+    { // pseudo-indices
     case LUA_REGISTRYINDEX:
         return registry(L);
     case LUA_ENVIRONINDEX:
@@ -129,7 +129,7 @@ int lua_checkstack(lua_State* L, int size)
 {
     int res = 1;
     if (size > LUAI_MAXCSTACK || (L->top - L->base + size) > LUAI_MAXCSTACK)
-        res = 0; /* stack overflow */
+        res = 0; // stack overflow
     else if (size > 0)
     {
         luaD_checkstack(L, size);
@@ -219,7 +219,7 @@ void lua_settop(lua_State* L, int idx)
     else
     {
         api_check(L, -(idx + 1) <= (L->top - L->base));
-        L->top += idx + 1; /* `subtract' index (index is negative) */
+        L->top += idx + 1; // `subtract' index (index is negative)
     }
     return;
 }
@@ -267,7 +267,7 @@ void lua_replace(lua_State* L, int idx)
     else
     {
         setobj(L, o, L->top - 1);
-        if (idx < LUA_GLOBALSINDEX) /* function upvalue? */
+        if (idx < LUA_GLOBALSINDEX) // function upvalue?
             luaC_barrier(L, curr_func(L), L->top - 1);
     }
     L->top--;
@@ -429,13 +429,13 @@ const char* lua_tolstring(lua_State* L, int idx, size_t* len)
     {
         luaC_checkthreadsleep(L);
         if (!luaV_tostring(L, o))
-        { /* conversion failed? */
+        { // conversion failed?
             if (len != NULL)
                 *len = 0;
             return NULL;
         }
         luaC_checkGC(L);
-        o = index2addr(L, idx); /* previous call may reallocate the stack */
+        o = index2addr(L, idx); // previous call may reallocate the stack
     }
     if (len != NULL)
         *len = tsvalue(o)->len;
@@ -660,7 +660,7 @@ void lua_pushcclosurek(lua_State* L, lua_CFunction fn, const char* debugname, in
 
 void lua_pushboolean(lua_State* L, int b)
 {
-    setbvalue(L->top, (b != 0)); /* ensure that true is 1 */
+    setbvalue(L->top, (b != 0)); // ensure that true is 1
     api_incr_top(L);
     return;
 }
@@ -829,7 +829,7 @@ void lua_settable(lua_State* L, int idx)
     StkId t = index2addr(L, idx);
     api_checkvalidindex(L, t);
     luaV_settable(L, t, L->top - 2, L->top - 1);
-    L->top -= 2; /* pop index and value */
+    L->top -= 2; // pop index and value
     return;
 }
 
@@ -967,7 +967,7 @@ void lua_call(lua_State* L, int nargs, int nresults)
 ** Execute a protected call.
 */
 struct CallS
-{ /* data to `f_call' */
+{ // data to `f_call'
     StkId func;
     int nresults;
 };
@@ -992,7 +992,7 @@ int lua_pcall(lua_State* L, int nargs, int nresults, int errfunc)
         func = savestack(L, o);
     }
     struct CallS c;
-    c.func = L->top - (nargs + 1); /* function to be called */
+    c.func = L->top - (nargs + 1); // function to be called
     c.nresults = nresults;
 
     int status = luaD_pcall(L, f_call, &c, savestack(L, c.func), func);
@@ -1044,7 +1044,7 @@ int lua_gc(lua_State* L, int what, int data)
     }
     case LUA_GCCOUNT:
     {
-        /* GC values are expressed in Kbytes: #bytes/2^10 */
+        // GC values are expressed in Kbytes: #bytes/2^10
         res = cast_int(g->totalbytes >> 10);
         break;
     }
@@ -1084,8 +1084,8 @@ int lua_gc(lua_State* L, int what, int data)
             actualwork += stepsize;
 
             if (g->gcstate == GCSpause)
-            {            /* end of cycle? */
-                res = 1; /* signal it */
+            {            // end of cycle?
+                res = 1; // signal it
                 break;
             }
         }
@@ -1137,13 +1137,13 @@ int lua_gc(lua_State* L, int what, int data)
     }
     case LUA_GCSETSTEPSIZE:
     {
-        /* GC values are expressed in Kbytes: #bytes/2^10 */
+        // GC values are expressed in Kbytes: #bytes/2^10
         res = g->gcstepsize >> 10;
         g->gcstepsize = data << 10;
         break;
     }
     default:
-        res = -1; /* invalid option */
+        res = -1; // invalid option
     }
     return res;
 }
@@ -1169,8 +1169,8 @@ int lua_next(lua_State* L, int idx)
     {
         api_incr_top(L);
     }
-    else             /* no more elements */
-        L->top -= 1; /* remove key */
+    else             // no more elements
+        L->top -= 1; // remove key
     return more;
 }
 
@@ -1185,12 +1185,12 @@ void lua_concat(lua_State* L, int n)
         L->top -= (n - 1);
     }
     else if (n == 0)
-    { /* push empty string */
+    { // push empty string
         luaC_checkthreadsleep(L);
         setsvalue2s(L, L->top, luaS_newlstr(L, "", 0));
         api_incr_top(L);
     }
-    /* else n == 1; nothing to do */
+    // else n == 1; nothing to do
     return;
 }
 
@@ -1277,7 +1277,7 @@ uintptr_t lua_encodepointer(lua_State* L, uintptr_t p)
 
 int lua_ref(lua_State* L, int idx)
 {
-    api_check(L, idx != LUA_REGISTRYINDEX); /* idx is a stack index for value */
+    api_check(L, idx != LUA_REGISTRYINDEX); // idx is a stack index for value
     int ref = LUA_REFNIL;
     global_State* g = L->global;
     StkId p = index2addr(L, idx);
@@ -1286,13 +1286,13 @@ int lua_ref(lua_State* L, int idx)
         Table* reg = hvalue(registry(L));
 
         if (g->registryfree != 0)
-        { /* reuse existing slot */
+        { // reuse existing slot
             ref = g->registryfree;
         }
         else
-        { /* no free elements */
+        { // no free elements
             ref = luaH_getn(reg);
-            ref++; /* create new reference */
+            ref++; // create new reference
         }
 
         TValue* slot = luaH_setnum(L, reg, ref);
@@ -1312,7 +1312,7 @@ void lua_unref(lua_State* L, int ref)
     global_State* g = L->global;
     Table* reg = hvalue(registry(L));
     TValue* slot = luaH_setnum(L, reg, ref);
-    setnvalue(slot, g->registryfree); /* NB: no barrier needed because value isn't collectable */
+    setnvalue(slot, g->registryfree); // NB: no barrier needed because value isn't collectable
     g->registryfree = ref;
     return;
 }

VM/src/laux.cpp

@@ -11,7 +11,7 @@
 
 #include <string.h>
 
-/* convert a stack index to positive */
+// convert a stack index to positive
 #define abs_index(L, i) ((i) > 0 || (i) <= LUA_REGISTRYINDEX ? (i) : lua_gettop(L) + (i) + 1)
 
 /*
@@ -75,7 +75,7 @@ void luaL_where(lua_State* L, int level)
         lua_pushfstring(L, "%s:%d: ", ar.short_src, ar.currentline);
         return;
     }
-    lua_pushliteral(L, ""); /* else, no information available... */
+    lua_pushliteral(L, ""); // else, no information available...
 }
 
 l_noret luaL_errorL(lua_State* L, const char* fmt, ...)
@@ -89,7 +89,7 @@ l_noret luaL_errorL(lua_State* L, const char* fmt, ...)
     lua_error(L);
 }
 
-/* }====================================================== */
+// }======================================================
 
 int luaL_checkoption(lua_State* L, int narg, const char* def, const char* const lst[])
 {
@@ -104,13 +104,13 @@ int luaL_checkoption(lua_State* L, int narg, const char* def, const char* const
 
 int luaL_newmetatable(lua_State* L, const char* tname)
 {
-    lua_getfield(L, LUA_REGISTRYINDEX, tname); /* get registry.name */
-    if (!lua_isnil(L, -1))                     /* name already in use? */
-        return 0;                              /* leave previous value on top, but return 0 */
+    lua_getfield(L, LUA_REGISTRYINDEX, tname); // get registry.name
+    if (!lua_isnil(L, -1))                     // name already in use?
+        return 0;                              // leave previous value on top, but return 0
     lua_pop(L, 1);
-    lua_newtable(L); /* create metatable */
+    lua_newtable(L); // create metatable
     lua_pushvalue(L, -1);
-    lua_setfield(L, LUA_REGISTRYINDEX, tname); /* registry.name = metatable */
+    lua_setfield(L, LUA_REGISTRYINDEX, tname); // registry.name = metatable
     return 1;
 }
 
@@ -118,18 +118,18 @@ void* luaL_checkudata(lua_State* L, int ud, const char* tname)
 {
     void* p = lua_touserdata(L, ud);
     if (p != NULL)
-    { /* value is a userdata? */
+    { // value is a userdata?
         if (lua_getmetatable(L, ud))
-        {                                              /* does it have a metatable? */
-            lua_getfield(L, LUA_REGISTRYINDEX, tname); /* get correct metatable */
+        {                                              // does it have a metatable?
+            lua_getfield(L, LUA_REGISTRYINDEX, tname); // get correct metatable
             if (lua_rawequal(L, -1, -2))
-            {                  /* does it have the correct mt? */
-                lua_pop(L, 2); /* remove both metatables */
+            {                  // does it have the correct mt?
+                lua_pop(L, 2); // remove both metatables
                 return p;
             }
         }
     }
-    luaL_typeerrorL(L, ud, tname); /* else error */
+    luaL_typeerrorL(L, ud, tname); // else error
 }
 
 void luaL_checkstack(lua_State* L, int space, const char* mes)
@@ -243,18 +243,18 @@ const float* luaL_optvector(lua_State* L, int narg, const float* def)
 
 int luaL_getmetafield(lua_State* L, int obj, const char* event)
 {
-    if (!lua_getmetatable(L, obj)) /* no metatable? */
+    if (!lua_getmetatable(L, obj)) // no metatable?
         return 0;
     lua_pushstring(L, event);
     lua_rawget(L, -2);
     if (lua_isnil(L, -1))
     {
-        lua_pop(L, 2); /* remove metatable and metafield */
+        lua_pop(L, 2); // remove metatable and metafield
         return 0;
     }
     else
     {
-        lua_remove(L, -2); /* remove only metatable */
+        lua_remove(L, -2); // remove only metatable
         return 1;
     }
 }
@@ -262,7 +262,7 @@ int luaL_getmetafield(lua_State* L, int obj, const char* event)
 int luaL_callmeta(lua_State* L, int obj, const char* event)
 {
     obj = abs_index(L, obj);
-    if (!luaL_getmetafield(L, obj, event)) /* no metafield? */
+    if (!luaL_getmetafield(L, obj, event)) // no metafield?
         return 0;
     lua_pushvalue(L, obj);
     lua_call(L, 1, 1);
@@ -282,19 +282,19 @@ void luaL_register(lua_State* L, const char* libname, const luaL_Reg* l)
     if (libname)
     {
         int size = libsize(l);
-        /* check whether lib already exists */
+        // check whether lib already exists
         luaL_findtable(L, LUA_REGISTRYINDEX, "_LOADED", 1);
-        lua_getfield(L, -1, libname); /* get _LOADED[libname] */
+        lua_getfield(L, -1, libname); // get _LOADED[libname]
         if (!lua_istable(L, -1))
-        {                  /* not found? */
-            lua_pop(L, 1); /* remove previous result */
-            /* try global variable (and create one if it does not exist) */
+        {                  // not found?
+            lua_pop(L, 1); // remove previous result
+            // try global variable (and create one if it does not exist)
             if (luaL_findtable(L, LUA_GLOBALSINDEX, libname, size) != NULL)
                 luaL_error(L, "name conflict for module '%s'", libname);
             lua_pushvalue(L, -1);
-            lua_setfield(L, -3, libname); /* _LOADED[libname] = new table */
+            lua_setfield(L, -3, libname); // _LOADED[libname] = new table
         }
-        lua_remove(L, -2); /* remove _LOADED table */
+        lua_remove(L, -2); // remove _LOADED table
     }
     for (; l->name; l++)
     {
@@ -315,19 +315,19 @@ const char* luaL_findtable(lua_State* L, int idx, const char* fname, int szhint)
         lua_pushlstring(L, fname, e - fname);
         lua_rawget(L, -2);
         if (lua_isnil(L, -1))
-        {                                                    /* no such field? */
-            lua_pop(L, 1);                                   /* remove this nil */
-            lua_createtable(L, 0, (*e == '.' ? 1 : szhint)); /* new table for field */
+        {                                                    // no such field?
+            lua_pop(L, 1);                                   // remove this nil
+            lua_createtable(L, 0, (*e == '.' ? 1 : szhint)); // new table for field
             lua_pushlstring(L, fname, e - fname);
             lua_pushvalue(L, -2);
-            lua_settable(L, -4); /* set new table into field */
+            lua_settable(L, -4); // set new table into field
         }
         else if (!lua_istable(L, -1))
-        {                  /* field has a non-table value? */
-            lua_pop(L, 2); /* remove table and value */
-            return fname;  /* return problematic part of the name */
+        {                  // field has a non-table value?
+            lua_pop(L, 2); // remove table and value
+            return fname;  // return problematic part of the name
         }
-        lua_remove(L, -2); /* remove previous table */
+        lua_remove(L, -2); // remove previous table
         fname = e + 1;
     } while (*e == '.');
     return NULL;
@@ -470,11 +470,11 @@ void luaL_pushresultsize(luaL_Buffer* B, size_t size)
     luaL_pushresult(B);
 }
 
-/* }====================================================== */
+// }======================================================
 
 const char* luaL_tolstring(lua_State* L, int idx, size_t* len)
 {
-    if (luaL_callmeta(L, idx, "__tostring")) /* is there a metafield? */
+    if (luaL_callmeta(L, idx, "__tostring")) // is there a metafield?
     {
         if (!lua_isstring(L, -1))
             luaL_error(L, "'__tostring' must return a string");

VM/src/lbaselib.cpp

@@ -11,8 +11,6 @@
 #include <stdio.h>
 #include <stdlib.h>
 
-LUAU_FASTFLAG(LuauLenTM)
-
 static void writestring(const char* s, size_t l)
 {
     fwrite(s, 1, l, stdout);
@@ -20,15 +18,15 @@ static void writestring(const char* s, size_t l)
 
 static int luaB_print(lua_State* L)
 {
-    int n = lua_gettop(L); /* number of arguments */
+    int n = lua_gettop(L); // number of arguments
     for (int i = 1; i <= n; i++)
     {
         size_t l;
-        const char* s = luaL_tolstring(L, i, &l); /* convert to string using __tostring et al */
+        const char* s = luaL_tolstring(L, i, &l); // convert to string using __tostring et al
         if (i > 1)
             writestring("\t", 1);
         writestring(s, l);
-        lua_pop(L, 1); /* pop result */
+        lua_pop(L, 1); // pop result
     }
     writestring("\n", 1);
     return 0;
@@ -38,7 +36,7 @@ static int luaB_tonumber(lua_State* L)
 {
     int base = luaL_optinteger(L, 2, 10);
     if (base == 10)
-    { /* standard conversion */
+    { // standard conversion
         int isnum = 0;
         double n = lua_tonumberx(L, 1, &isnum);
         if (isnum)
@@ -46,7 +44,7 @@ static int luaB_tonumber(lua_State* L)
             lua_pushnumber(L, n);
             return 1;
         }
-        luaL_checkany(L, 1); /* error if we don't have any argument */
+        luaL_checkany(L, 1); // error if we don't have any argument
     }
     else
     {
@@ -56,17 +54,17 @@ static int luaB_tonumber(lua_State* L)
         unsigned long long n;
         n = strtoull(s1, &s2, base);
         if (s1 != s2)
-        { /* at least one valid digit? */
+        { // at least one valid digit?
             while (isspace((unsigned char)(*s2)))
-                s2++; /* skip trailing spaces */
+                s2++; // skip trailing spaces
             if (*s2 == '\0')
-            { /* no invalid trailing characters? */
+            { // no invalid trailing characters?
                 lua_pushnumber(L, (double)n);
                 return 1;
             }
         }
     }
-    lua_pushnil(L); /* else not a number */
+    lua_pushnil(L); // else not a number
     return 1;
 }
 
@@ -75,7 +73,7 @@ static int luaB_error(lua_State* L)
     int level = luaL_optinteger(L, 2, 1);
     lua_settop(L, 1);
     if (lua_isstring(L, 1) && level > 0)
-    { /* add extra information? */
+    { // add extra information?
         luaL_where(L, level);
         lua_pushvalue(L, 1);
         lua_concat(L, 2);
@@ -89,10 +87,10 @@ static int luaB_getmetatable(lua_State* L)
     if (!lua_getmetatable(L, 1))
     {
         lua_pushnil(L);
-        return 1; /* no metatable */
+        return 1; // no metatable
     }
     luaL_getmetafield(L, 1, "__metatable");
-    return 1; /* returns either __metatable field (if present) or metatable */
+    return 1; // returns either __metatable field (if present) or metatable
 }
 
 static int luaB_setmetatable(lua_State* L)
@@ -126,8 +124,8 @@ static void getfunc(lua_State* L, int opt)
 static int luaB_getfenv(lua_State* L)
 {
     getfunc(L, 1);
-    if (lua_iscfunction(L, -1))             /* is a C function? */
-        lua_pushvalue(L, LUA_GLOBALSINDEX); /* return the thread's global env. */
+    if (lua_iscfunction(L, -1))             // is a C function?
+        lua_pushvalue(L, LUA_GLOBALSINDEX); // return the thread's global env.
     else
         lua_getfenv(L, -1);
     lua_setsafeenv(L, -1, false);
@@ -142,7 +140,7 @@ static int luaB_setfenv(lua_State* L)
     lua_setsafeenv(L, -1, false);
     if (lua_isnumber(L, 1) && lua_tonumber(L, 1) == 0)
     {
-        /* change environment of current thread */
+        // change environment of current thread
         lua_pushthread(L);
         lua_insert(L, -2);
         lua_setfenv(L, -2);
@@ -182,9 +180,6 @@ static int luaB_rawset(lua_State* L)
 
 static int luaB_rawlen(lua_State* L)
 {
-    if (!FFlag::LuauLenTM)
-        luaL_error(L, "'rawlen' is not available");
-
     int tt = lua_type(L, 1);
     luaL_argcheck(L, tt == LUA_TTABLE || tt == LUA_TSTRING, 1, "table or string expected");
     int len = lua_objlen(L, 1);
@@ -201,7 +196,7 @@ static int luaB_gcinfo(lua_State* L)
 static int luaB_type(lua_State* L)
 {
     luaL_checkany(L, 1);
-    /* resulting name doesn't differentiate between userdata types */
+    // resulting name doesn't differentiate between userdata types
     lua_pushstring(L, lua_typename(L, lua_type(L, 1)));
     return 1;
 }
@@ -209,7 +204,7 @@ static int luaB_type(lua_State* L)
 static int luaB_typeof(lua_State* L)
 {
     luaL_checkany(L, 1);
-    /* resulting name returns __type if specified unless the input is a newproxy-created userdata */
+    // resulting name returns __type if specified unless the input is a newproxy-created userdata
     lua_pushstring(L, luaL_typename(L, 1));
     return 1;
 }
@@ -217,7 +212,7 @@ static int luaB_typeof(lua_State* L)
 int luaB_next(lua_State* L)
 {
     luaL_checktype(L, 1, LUA_TTABLE);
-    lua_settop(L, 2); /* create a 2nd argument if there isn't one */
+    lua_settop(L, 2); // create a 2nd argument if there isn't one
     if (lua_next(L, 1))
         return 2;
     else
@@ -230,9 +225,9 @@ int luaB_next(lua_State* L)
 static int luaB_pairs(lua_State* L)
 {
     luaL_checktype(L, 1, LUA_TTABLE);
-    lua_pushvalue(L, lua_upvalueindex(1)); /* return generator, */
-    lua_pushvalue(L, 1);                   /* state, */
-    lua_pushnil(L);                        /* and initial value */
+    lua_pushvalue(L, lua_upvalueindex(1)); // return generator,
+    lua_pushvalue(L, 1);                   // state,
+    lua_pushnil(L);                        // and initial value
     return 3;
 }
 
@@ -240,7 +235,7 @@ int luaB_inext(lua_State* L)
 {
     int i = luaL_checkinteger(L, 2);
     luaL_checktype(L, 1, LUA_TTABLE);
-    i++; /* next value */
+    i++; // next value
     lua_pushinteger(L, i);
     lua_rawgeti(L, 1, i);
     return (lua_isnil(L, -1)) ? 0 : 2;
@@ -249,9 +244,9 @@ int luaB_inext(lua_State* L)
 static int luaB_ipairs(lua_State* L)
 {
     luaL_checktype(L, 1, LUA_TTABLE);
-    lua_pushvalue(L, lua_upvalueindex(1)); /* return generator, */
-    lua_pushvalue(L, 1);                   /* state, */
-    lua_pushinteger(L, 0);                 /* and initial value */
+    lua_pushvalue(L, lua_upvalueindex(1)); // return generator,
+    lua_pushvalue(L, 1);                   // state,
+    lua_pushinteger(L, 0);                 // and initial value
     return 3;
 }
 
@@ -340,12 +335,12 @@ static int luaB_xpcally(lua_State* L)
 {
     luaL_checktype(L, 2, LUA_TFUNCTION);
 
-    /* swap function & error function */
+    // swap function & error function
     lua_pushvalue(L, 1);
     lua_pushvalue(L, 2);
     lua_replace(L, 1);
     lua_replace(L, 2);
-    /* at this point the stack looks like err, f, args */
+    // at this point the stack looks like err, f, args
 
     // any errors from this point on are handled by continuation
     L->ci->flags |= LUA_CALLINFO_HANDLE;
@@ -386,7 +381,7 @@ static int luaB_xpcallcont(lua_State* L, int status)
         lua_rawcheckstack(L, 1);
         lua_pushboolean(L, true);
         lua_replace(L, 1);    // replace error function with status
-        return lua_gettop(L); /* return status + all results */
+        return lua_gettop(L); // return status + all results
     }
     else
     {
@@ -462,16 +457,16 @@ static void auxopen(lua_State* L, const char* name, lua_CFunction f, lua_CFuncti
 
 int luaopen_base(lua_State* L)
 {
-    /* set global _G */
+    // set global _G
     lua_pushvalue(L, LUA_GLOBALSINDEX);
     lua_setglobal(L, "_G");
 
-    /* open lib into global table */
+    // open lib into global table
     luaL_register(L, "_G", base_funcs);
     lua_pushliteral(L, "Luau");
-    lua_setglobal(L, "_VERSION"); /* set global _VERSION */
+    lua_setglobal(L, "_VERSION"); // set global _VERSION
 
-    /* `ipairs' and `pairs' need auxiliary functions as upvalues */
+    // `ipairs' and `pairs' need auxiliary functions as upvalues
     auxopen(L, "ipairs", luaB_ipairs, luaB_inext);
     auxopen(L, "pairs", luaB_pairs, luaB_next);
 

VM/src/lbitlib.cpp

@@ -8,10 +8,10 @@
 #define ALLONES ~0u
 #define NBITS int(8 * sizeof(unsigned))
 
-/* macro to trim extra bits */
+// macro to trim extra bits
 #define trim(x) ((x)&ALLONES)
 
-/* builds a number with 'n' ones (1 <= n <= NBITS) */
+// builds a number with 'n' ones (1 <= n <= NBITS)
 #define mask(n) (~((ALLONES << 1) << ((n)-1)))
 
 typedef unsigned b_uint;
@@ -69,7 +69,7 @@ static int b_not(lua_State* L)
 static int b_shift(lua_State* L, b_uint r, int i)
 {
     if (i < 0)
-    { /* shift right? */
+    { // shift right?
         i = -i;
         r = trim(r);
         if (i >= NBITS)
@@ -78,7 +78,7 @@ static int b_shift(lua_State* L, b_uint r, int i)
             r >>= i;
     }
     else
-    { /* shift left */
+    { // shift left
         if (i >= NBITS)
             r = 0;
         else
@@ -106,11 +106,11 @@ static int b_arshift(lua_State* L)
     if (i < 0 || !(r & ((b_uint)1 << (NBITS - 1))))
         return b_shift(L, r, -i);
     else
-    { /* arithmetic shift for 'negative' number */
+    { // arithmetic shift for 'negative' number
         if (i >= NBITS)
             r = ALLONES;
         else
-            r = trim((r >> i) | ~(~(b_uint)0 >> i)); /* add signal bit */
+            r = trim((r >> i) | ~(~(b_uint)0 >> i)); // add signal bit
         lua_pushunsigned(L, r);
         return 1;
     }
@@ -119,9 +119,9 @@ static int b_arshift(lua_State* L)
 static int b_rot(lua_State* L, int i)
 {
     b_uint r = luaL_checkunsigned(L, 1);
-    i &= (NBITS - 1); /* i = i % NBITS */
+    i &= (NBITS - 1); // i = i % NBITS
     r = trim(r);
-    if (i != 0) /* avoid undefined shift of NBITS when i == 0 */
+    if (i != 0) // avoid undefined shift of NBITS when i == 0
         r = (r << i) | (r >> (NBITS - i));
     lua_pushunsigned(L, trim(r));
     return 1;
@@ -172,7 +172,7 @@ static int b_replace(lua_State* L)
     b_uint v = luaL_checkunsigned(L, 2);
     int f = fieldargs(L, 3, &w);
     int m = mask(w);
-    v &= m; /* erase bits outside given width */
+    v &= m; // erase bits outside given width
     r = (r & ~(m << f)) | (v << f);
     lua_pushunsigned(L, r);
     return 1;

VM/src/lcommon.h

@@ -11,7 +11,7 @@
 
 typedef LUAI_USER_ALIGNMENT_T L_Umaxalign;
 
-/* internal assertions for in-house debugging */
+// internal assertions for in-house debugging
 #define check_exp(c, e) (LUAU_ASSERT(c), (e))
 #define api_check(l, e) LUAU_ASSERT(e)
 

VM/src/lcorolib.cpp

@@ -5,9 +5,9 @@
 #include "lstate.h"
 #include "lvm.h"
 
-#define CO_RUN 0 /* running */
-#define CO_SUS 1 /* suspended */
-#define CO_NOR 2 /* 'normal' (it resumed another coroutine) */
+#define CO_RUN 0 // running
+#define CO_SUS 1 // suspended
+#define CO_NOR 2 // 'normal' (it resumed another coroutine)
 #define CO_DEAD 3
 
 #define CO_STATUS_ERROR -1
@@ -23,13 +23,13 @@ static int auxstatus(lua_State* L, lua_State* co)
         return CO_SUS;
     if (co->status == LUA_BREAK)
         return CO_NOR;
-    if (co->status != 0) /* some error occurred */
+    if (co->status != 0) // some error occurred
         return CO_DEAD;
-    if (co->ci != co->base_ci) /* does it have frames? */
+    if (co->ci != co->base_ci) // does it have frames?
         return CO_NOR;
     if (co->top == co->base)
         return CO_DEAD;
-    return CO_SUS; /* initial state */
+    return CO_SUS; // initial state
 }
 
 static int costatus(lua_State* L)
@@ -68,10 +68,10 @@ static int auxresume(lua_State* L, lua_State* co, int narg)
         int nres = cast_int(co->top - co->base);
         if (nres)
         {
-            /* +1 accounts for true/false status in resumefinish */
+            // +1 accounts for true/false status in resumefinish
             if (nres + 1 > LUA_MINSTACK && !lua_checkstack(L, nres + 1))
                 luaL_error(L, "too many results to resume");
-            lua_xmove(co, L, nres); /* move yielded values */
+            lua_xmove(co, L, nres); // move yielded values
         }
         return nres;
     }
@@ -81,7 +81,7 @@ static int auxresume(lua_State* L, lua_State* co, int narg)
     }
     else
     {
-        lua_xmove(co, L, 1); /* move error message */
+        lua_xmove(co, L, 1); // move error message
         return CO_STATUS_ERROR;
     }
 }
@@ -102,13 +102,13 @@ static int auxresumecont(lua_State* L, lua_State* co)
         int nres = cast_int(co->top - co->base);
         if (!lua_checkstack(L, nres + 1))
             luaL_error(L, "too many results to resume");
-        lua_xmove(co, L, nres); /* move yielded values */
+        lua_xmove(co, L, nres); // move yielded values
         return nres;
     }
     else
     {
         lua_rawcheckstack(L, 2);
-        lua_xmove(co, L, 1); /* move error message */
+        lua_xmove(co, L, 1); // move error message
         return CO_STATUS_ERROR;
     }
 }
@@ -119,13 +119,13 @@ static int coresumefinish(lua_State* L, int r)
     {
         lua_pushboolean(L, 0);
         lua_insert(L, -2);
-        return 2; /* return false + error message */
+        return 2; // return false + error message
     }
     else
     {
         lua_pushboolean(L, 1);
         lua_insert(L, -(r + 1));
-        return r + 1; /* return true + `resume' returns */
+        return r + 1; // return true + `resume' returns
     }
 }
 
@@ -161,12 +161,12 @@ static int auxwrapfinish(lua_State* L, int r)
     if (r < 0)
     {
         if (lua_isstring(L, -1))
-        {                     /* error object is a string? */
-            luaL_where(L, 1); /* add extra info */
+        {                     // error object is a string?
+            luaL_where(L, 1); // add extra info
             lua_insert(L, -2);
             lua_concat(L, 2);
         }
-        lua_error(L); /* propagate error */
+        lua_error(L); // propagate error
     }
     return r;
 }
@@ -221,7 +221,7 @@ static int coyield(lua_State* L)
 static int corunning(lua_State* L)
 {
     if (lua_pushthread(L))
-        lua_pushnil(L); /* main thread is not a coroutine */
+        lua_pushnil(L); // main thread is not a coroutine
     return 1;
 }
 
@@ -250,7 +250,7 @@ static int coclose(lua_State* L)
     {
         lua_pushboolean(L, false);
         if (lua_gettop(co))
-            lua_xmove(co, L, 1); /* move error message */
+            lua_xmove(co, L, 1); // move error message
         lua_resetthread(co);
         return 2;
     }

VM/src/ldblib.cpp

@@ -82,9 +82,9 @@ static int db_info(lua_State* L)
 
         case 'f':
             if (L1 == L)
-                lua_pushvalue(L, -1 - results); /* function is right before results */
+                lua_pushvalue(L, -1 - results); // function is right before results
             else
-                lua_xmove(L1, L, 1); /* function is at top of L1 */
+                lua_xmove(L1, L, 1); // function is at top of L1
             results++;
             break;
 

VM/src/ldebug.cpp

@@ -86,7 +86,7 @@ const char* lua_setlocal(lua_State* L, int level, int n)
     const LocVar* var = fp ? luaF_getlocal(fp, n, currentpc(L, ci)) : NULL;
     if (var)
         setobjs2s(L, ci->base + var->reg, L->top - 1);
-    L->top--; /* pop value */
+    L->top--; // pop value
     const char* name = var ? getstr(var->varname) : NULL;
     return name;
 }
@@ -269,6 +269,13 @@ l_noret luaG_indexerror(lua_State* L, const TValue* p1, const TValue* p2)
         luaG_runerror(L, "attempt to index %s with %s", t1, t2);
 }
 
+l_noret luaG_methoderror(lua_State* L, const TValue* p1, const TString* p2)
+{
+    const char* t1 = luaT_objtypename(L, p1);
+
+    luaG_runerror(L, "attempt to call missing method '%s' of %s", getstr(p2), t1);
+}
+
 l_noret luaG_readonlyerror(lua_State* L)
 {
     luaG_runerror(L, "attempt to modify a readonly table");
@@ -279,7 +286,7 @@ static void pusherror(lua_State* L, const char* msg)
     CallInfo* ci = L->ci;
     if (isLua(ci))
     {
-        char buff[LUA_IDSIZE]; /* add file:line information */
+        char buff[LUA_IDSIZE]; // add file:line information
         luaO_chunkid(buff, getstr(getluaproto(ci)->source), LUA_IDSIZE);
         int line = currentline(L, ci);
         luaO_pushfstring(L, "%s:%d: %s", buff, line, msg);

VM/src/ldebug.h

@@ -19,6 +19,7 @@ LUAI_FUNC l_noret luaG_concaterror(lua_State* L, StkId p1, StkId p2);
 LUAI_FUNC l_noret luaG_aritherror(lua_State* L, const TValue* p1, const TValue* p2, TMS op);
 LUAI_FUNC l_noret luaG_ordererror(lua_State* L, const TValue* p1, const TValue* p2, TMS op);
 LUAI_FUNC l_noret luaG_indexerror(lua_State* L, const TValue* p1, const TValue* p2);
+LUAI_FUNC l_noret luaG_methoderror(lua_State* L, const TValue* p1, const TString* p2);
 LUAI_FUNC l_noret luaG_readonlyerror(lua_State* L);
 
 LUAI_FUNC LUA_PRINTF_ATTR(2, 3) l_noret luaG_runerrorL(lua_State* L, const char* fmt, ...);

VM/src/ldo.cpp

@@ -31,7 +31,7 @@ struct lua_jmpbuf
     jmp_buf buf;
 };
 
-/* use POSIX versions of setjmp/longjmp if possible: they don't save/restore signal mask and are therefore faster */
+// use POSIX versions of setjmp/longjmp if possible: they don't save/restore signal mask and are therefore faster
 #if defined(__linux__) || defined(__APPLE__)
 #define LUAU_SETJMP(buf) _setjmp(buf)
 #define LUAU_LONGJMP(buf, code) _longjmp(buf, code)
@@ -153,7 +153,7 @@ l_noret luaD_throw(lua_State* L, int errcode)
 }
 #endif
 
-/* }====================================================== */
+// }======================================================
 
 static void correctstack(lua_State* L, TValue* oldstack)
 {
@@ -177,7 +177,7 @@ void luaD_reallocstack(lua_State* L, int newsize)
     luaM_reallocarray(L, L->stack, L->stacksize, realsize, TValue, L->memcat);
     TValue* newstack = L->stack;
     for (int i = L->stacksize; i < realsize; i++)
-        setnilvalue(newstack + i); /* erase new segment */
+        setnilvalue(newstack + i); // erase new segment
     L->stacksize = realsize;
     L->stack_last = newstack + newsize;
     correctstack(L, oldstack);
@@ -194,7 +194,7 @@ void luaD_reallocCI(lua_State* L, int newsize)
 
 void luaD_growstack(lua_State* L, int n)
 {
-    if (n <= L->stacksize) /* double size is enough? */
+    if (n <= L->stacksize) // double size is enough?
         luaD_reallocstack(L, 2 * L->stacksize);
     else
         luaD_reallocstack(L, L->stacksize + n);
@@ -202,11 +202,11 @@ void luaD_growstack(lua_State* L, int n)
 
 CallInfo* luaD_growCI(lua_State* L)
 {
-    /* allow extra stack space to handle stack overflow in xpcall */
+    // allow extra stack space to handle stack overflow in xpcall
     const int hardlimit = LUAI_MAXCALLS + (LUAI_MAXCALLS >> 3);
 
     if (L->size_ci >= hardlimit)
-        luaD_throw(L, LUA_ERRERR); /* error while handling stack error */
+        luaD_throw(L, LUA_ERRERR); // error while handling stack error
 
     int request = L->size_ci * 2;
     luaD_reallocCI(L, L->size_ci >= LUAI_MAXCALLS ? hardlimit : request < LUAI_MAXCALLS ? request : LUAI_MAXCALLS);
@@ -219,13 +219,13 @@ CallInfo* luaD_growCI(lua_State* L)
 
 void luaD_checkCstack(lua_State* L)
 {
-    /* allow extra stack space to handle stack overflow in xpcall */
+    // allow extra stack space to handle stack overflow in xpcall
     const int hardlimit = LUAI_MAXCCALLS + (LUAI_MAXCCALLS >> 3);
 
     if (L->nCcalls == LUAI_MAXCCALLS)
         luaG_runerror(L, "C stack overflow");
     else if (L->nCcalls >= hardlimit)
-        luaD_throw(L, LUA_ERRERR); /* error while handling stack error */
+        luaD_throw(L, LUA_ERRERR); // error while handling stack error
 }
 
 /*
@@ -240,14 +240,14 @@ void luaD_call(lua_State* L, StkId func, int nResults)
         luaD_checkCstack(L);
 
     if (luau_precall(L, func, nResults) == PCRLUA)
-    {                                        /* is a Lua function? */
-        L->ci->flags |= LUA_CALLINFO_RETURN; /* luau_execute will stop after returning from the stack frame */
+    {                                        // is a Lua function?
+        L->ci->flags |= LUA_CALLINFO_RETURN; // luau_execute will stop after returning from the stack frame
 
         int oldactive = luaC_threadactive(L);
         l_setbit(L->stackstate, THREAD_ACTIVEBIT);
         luaC_checkthreadsleep(L);
 
-        luau_execute(L); /* call it */
+        luau_execute(L); // call it
 
         if (!oldactive)
             resetbit(L->stackstate, THREAD_ACTIVEBIT);
@@ -263,18 +263,18 @@ static void seterrorobj(lua_State* L, int errcode, StkId oldtop)
     {
     case LUA_ERRMEM:
     {
-        setsvalue2s(L, oldtop, luaS_newliteral(L, LUA_MEMERRMSG)); /* can not fail because string is pinned in luaopen */
+        setsvalue2s(L, oldtop, luaS_newliteral(L, LUA_MEMERRMSG)); // can not fail because string is pinned in luaopen
         break;
     }
     case LUA_ERRERR:
     {
-        setsvalue2s(L, oldtop, luaS_newliteral(L, LUA_ERRERRMSG)); /* can not fail because string is pinned in luaopen */
+        setsvalue2s(L, oldtop, luaS_newliteral(L, LUA_ERRERRMSG)); // can not fail because string is pinned in luaopen
         break;
     }
     case LUA_ERRSYNTAX:
     case LUA_ERRRUN:
     {
-        setobjs2s(L, oldtop, L->top - 1); /* error message on current top */
+        setobjs2s(L, oldtop, L->top - 1); // error message on current top
         break;
     }
     }
@@ -430,8 +430,8 @@ static void resume_finish(lua_State* L, int status)
     resetbit(L->stackstate, THREAD_ACTIVEBIT);
 
     if (status != 0)
-    {                                  /* error? */
-        L->status = cast_byte(status); /* mark thread as `dead' */
+    {                                  // error?
+        L->status = cast_byte(status); // mark thread as `dead'
         seterrorobj(L, status, L->top);
         L->ci->top = L->top;
     }
@@ -503,7 +503,7 @@ int lua_yield(lua_State* L, int nresults)
 {
     if (L->nCcalls > L->baseCcalls)
         luaG_runerror(L, "attempt to yield across metamethod/C-call boundary");
-    L->base = L->top - nresults; /* protect stack slots below */
+    L->base = L->top - nresults; // protect stack slots below
     L->status = LUA_YIELD;
     return -1;
 }
@@ -535,9 +535,9 @@ static void restore_stack_limit(lua_State* L)
 {
     LUAU_ASSERT(L->stack_last - L->stack == L->stacksize - EXTRA_STACK);
     if (L->size_ci > LUAI_MAXCALLS)
-    { /* there was an overflow? */
+    { // there was an overflow?
         int inuse = cast_int(L->ci - L->base_ci);
-        if (inuse + 1 < LUAI_MAXCALLS) /* can `undo' overflow? */
+        if (inuse + 1 < LUAI_MAXCALLS) // can `undo' overflow?
             luaD_reallocCI(L, LUAI_MAXCALLS);
     }
 }
@@ -576,7 +576,7 @@ int luaD_pcall(lua_State* L, Pfunc func, void* u, ptrdiff_t old_top, ptrdiff_t e
         }
 
         StkId oldtop = restorestack(L, old_top);
-        luaF_close(L, oldtop); /* close eventual pending closures */
+        luaF_close(L, oldtop); // close eventual pending closures
         seterrorobj(L, status, oldtop);
         L->ci = restoreci(L, old_ci);
         L->base = L->ci->base;

VM/src/ldo.h

@@ -34,12 +34,12 @@
 #define saveci(L, p) ((char*)(p) - (char*)L->base_ci)
 #define restoreci(L, n) ((CallInfo*)((char*)L->base_ci + (n)))
 
-/* results from luaD_precall */
-#define PCRLUA 0   /* initiated a call to a Lua function */
-#define PCRC 1     /* did a call to a C function */
-#define PCRYIELD 2 /* C function yielded */
+// results from luaD_precall
+#define PCRLUA 0   // initiated a call to a Lua function
+#define PCRC 1     // did a call to a C function
+#define PCRYIELD 2 // C function yielded
 
-/* type of protected functions, to be ran by `runprotected' */
+// type of protected functions, to be ran by `runprotected'
 typedef void (*Pfunc)(lua_State* L, void* ud);
 
 LUAI_FUNC CallInfo* luaD_growCI(lua_State* L);

VM/src/lfunc.cpp

@@ -73,20 +73,20 @@ UpVal* luaF_findupval(lua_State* L, StkId level)
     {
         LUAU_ASSERT(p->v != &p->u.value);
         if (p->v == level)
-        {                                /* found a corresponding upvalue? */
-            if (isdead(g, obj2gco(p)))   /* is it dead? */
-                changewhite(obj2gco(p)); /* resurrect it */
+        {                                // found a corresponding upvalue?
+            if (isdead(g, obj2gco(p)))   // is it dead?
+                changewhite(obj2gco(p)); // resurrect it
             return p;
         }
 
         pp = &p->u.l.threadnext;
     }
 
-    UpVal* uv = luaM_newgco(L, UpVal, sizeof(UpVal), L->activememcat); /* not found: create a new one */
+    UpVal* uv = luaM_newgco(L, UpVal, sizeof(UpVal), L->activememcat); // not found: create a new one
     uv->tt = LUA_TUPVAL;
     uv->marked = luaC_white(g);
     uv->memcat = L->activememcat;
-    uv->v = level; /* current value lives in the stack */
+    uv->v = level; // current value lives in the stack
 
     // chain the upvalue in the threads open upvalue list at the proper position
     UpVal* next = *pp;
@@ -121,9 +121,9 @@ void luaF_unlinkupval(UpVal* uv)
 
 void luaF_freeupval(lua_State* L, UpVal* uv, lua_Page* page)
 {
-    if (uv->v != &uv->u.value)                            /* is it open? */
-        luaF_unlinkupval(uv);                             /* remove from open list */
-    luaM_freegco(L, uv, sizeof(UpVal), uv->memcat, page); /* free upvalue */
+    if (uv->v != &uv->u.value)                            // is it open?
+        luaF_unlinkupval(uv);                             // remove from open list
+    luaM_freegco(L, uv, sizeof(UpVal), uv->memcat, page); // free upvalue
 }
 
 void luaF_close(lua_State* L, StkId level)
@@ -179,11 +179,11 @@ const LocVar* luaF_getlocal(const Proto* f, int local_number, int pc)
     for (i = 0; i < f->sizelocvars; i++)
     {
         if (pc >= f->locvars[i].startpc && pc < f->locvars[i].endpc)
-        { /* is variable active? */
+        { // is variable active?
             local_number--;
             if (local_number == 0)
                 return &f->locvars[i];
         }
     }
-    return NULL; /* not found */
+    return NULL; // not found
 }

VM/src/lgc.cpp

@@ -125,7 +125,7 @@ static void removeentry(LuaNode* n)
 {
     LUAU_ASSERT(ttisnil(gval(n)));
     if (iscollectable(gkey(n)))
-        setttype(gkey(n), LUA_TDEADKEY); /* dead key; remove it */
+        setttype(gkey(n), LUA_TDEADKEY); // dead key; remove it
 }
 
 static void reallymarkobject(global_State* g, GCObject* o)
@@ -141,7 +141,7 @@ static void reallymarkobject(global_State* g, GCObject* o)
     case LUA_TUSERDATA:
     {
         Table* mt = gco2u(o)->metatable;
-        gray2black(o); /* udata are never gray */
+        gray2black(o); // udata are never gray
         if (mt)
             markobject(g, mt);
         return;
@@ -150,8 +150,8 @@ static void reallymarkobject(global_State* g, GCObject* o)
     {
         UpVal* uv = gco2uv(o);
         markvalue(g, uv->v);
-        if (uv->v == &uv->u.value) /* closed? */
-            gray2black(o);         /* open upvalues are never black */
+        if (uv->v == &uv->u.value) // closed?
+            gray2black(o);         // open upvalues are never black
         return;
     }
     case LUA_TFUNCTION:
@@ -201,15 +201,15 @@ static int traversetable(global_State* g, Table* h)
     if (h->metatable)
         markobject(g, cast_to(Table*, h->metatable));
 
-    /* is there a weak mode? */
+    // is there a weak mode?
     if (const char* modev = gettablemode(g, h))
     {
         weakkey = (strchr(modev, 'k') != NULL);
         weakvalue = (strchr(modev, 'v') != NULL);
         if (weakkey || weakvalue)
-        {                         /* is really weak? */
-            h->gclist = g->weak;  /* must be cleared after GC, ... */
-            g->weak = obj2gco(h); /* ... so put in the appropriate list */
+        {                         // is really weak?
+            h->gclist = g->weak;  // must be cleared after GC, ...
+            g->weak = obj2gco(h); // ... so put in the appropriate list
         }
     }
 
@@ -227,7 +227,7 @@ static int traversetable(global_State* g, Table* h)
         LuaNode* n = gnode(h, i);
         LUAU_ASSERT(ttype(gkey(n)) != LUA_TDEADKEY || ttisnil(gval(n)));
         if (ttisnil(gval(n)))
-            removeentry(n); /* remove empty entries */
+            removeentry(n); // remove empty entries
         else
         {
             LUAU_ASSERT(!ttisnil(gkey(n)));
@@ -251,20 +251,20 @@ static void traverseproto(global_State* g, Proto* f)
         stringmark(f->source);
     if (f->debugname)
         stringmark(f->debugname);
-    for (i = 0; i < f->sizek; i++) /* mark literals */
+    for (i = 0; i < f->sizek; i++) // mark literals
         markvalue(g, &f->k[i]);
     for (i = 0; i < f->sizeupvalues; i++)
-    { /* mark upvalue names */
+    { // mark upvalue names
         if (f->upvalues[i])
             stringmark(f->upvalues[i]);
     }
     for (i = 0; i < f->sizep; i++)
-    { /* mark nested protos */
+    { // mark nested protos
         if (f->p[i])
             markobject(g, f->p[i]);
     }
     for (i = 0; i < f->sizelocvars; i++)
-    { /* mark local-variable names */
+    { // mark local-variable names
         if (f->locvars[i].varname)
             stringmark(f->locvars[i].varname);
     }
@@ -276,7 +276,7 @@ static void traverseclosure(global_State* g, Closure* cl)
     if (cl->isC)
     {
         int i;
-        for (i = 0; i < cl->nupvalues; i++) /* mark its upvalues */
+        for (i = 0; i < cl->nupvalues; i++) // mark its upvalues
             markvalue(g, &cl->c.upvals[i]);
     }
     else
@@ -284,7 +284,7 @@ static void traverseclosure(global_State* g, Closure* cl)
         int i;
         LUAU_ASSERT(cl->nupvalues == cl->l.p->nups);
         markobject(g, cast_to(Proto*, cl->l.p));
-        for (i = 0; i < cl->nupvalues; i++) /* mark its upvalues */
+        for (i = 0; i < cl->nupvalues; i++) // mark its upvalues
             markvalue(g, &cl->l.uprefs[i]);
     }
 }
@@ -296,11 +296,11 @@ static void traversestack(global_State* g, lua_State* l, bool clearstack)
         stringmark(l->namecall);
     for (StkId o = l->stack; o < l->top; o++)
         markvalue(g, o);
-    /* final traversal? */
+    // final traversal?
     if (g->gcstate == GCSatomic || clearstack)
     {
         StkId stack_end = l->stack + l->stacksize;
-        for (StkId o = l->top; o < stack_end; o++) /* clear not-marked stack slice */
+        for (StkId o = l->top; o < stack_end; o++) // clear not-marked stack slice
             setnilvalue(o);
     }
 }
@@ -320,8 +320,8 @@ static size_t propagatemark(global_State* g)
     {
         Table* h = gco2h(o);
         g->gray = h->gclist;
-        if (traversetable(g, h)) /* table is weak? */
-            black2gray(o);       /* keep it gray */
+        if (traversetable(g, h)) // table is weak?
+            black2gray(o);       // keep it gray
         return sizeof(Table) + sizeof(TValue) * h->sizearray + sizeof(LuaNode) * sizenode(h);
     }
     case LUA_TFUNCTION:
@@ -393,7 +393,7 @@ static int isobjcleared(GCObject* o)
 {
     if (o->gch.tt == LUA_TSTRING)
     {
-        stringmark(&o->ts); /* strings are `values', so are never weak */
+        stringmark(&o->ts); // strings are `values', so are never weak
         return 0;
     }
 
@@ -417,8 +417,8 @@ static size_t cleartable(lua_State* L, GCObject* l)
         while (i--)
         {
             TValue* o = &h->array[i];
-            if (iscleared(o))   /* value was collected? */
-                setnilvalue(o); /* remove value */
+            if (iscleared(o))   // value was collected?
+                setnilvalue(o); // remove value
         }
         i = sizenode(h);
         int activevalues = 0;
@@ -432,8 +432,8 @@ static size_t cleartable(lua_State* L, GCObject* l)
                 // can we clear key or value?
                 if (iscleared(gkey(n)) || iscleared(gval(n)))
                 {
-                    setnilvalue(gval(n)); /* remove value ... */
-                    removeentry(n);       /* remove entry from table */
+                    setnilvalue(gval(n)); // remove value ...
+                    removeentry(n);       // remove entry from table
                 }
                 else
                 {
@@ -460,7 +460,7 @@ static size_t cleartable(lua_State* L, GCObject* l)
 
 static void shrinkstack(lua_State* L)
 {
-    /* compute used stack - note that we can't use th->top if we're in the middle of vararg call */
+    // compute used stack - note that we can't use th->top if we're in the middle of vararg call
     StkId lim = L->top;
     for (CallInfo* ci = L->base_ci; ci <= L->ci; ci++)
     {
@@ -469,16 +469,16 @@ static void shrinkstack(lua_State* L)
             lim = ci->top;
     }
 
-    /* shrink stack and callinfo arrays if we aren't using most of the space */
-    int ci_used = cast_int(L->ci - L->base_ci); /* number of `ci' in use */
-    int s_used = cast_int(lim - L->stack);      /* part of stack in use */
-    if (L->size_ci > LUAI_MAXCALLS)             /* handling overflow? */
-        return;                                 /* do not touch the stacks */
+    // shrink stack and callinfo arrays if we aren't using most of the space
+    int ci_used = cast_int(L->ci - L->base_ci); // number of `ci' in use
+    int s_used = cast_int(lim - L->stack);      // part of stack in use
+    if (L->size_ci > LUAI_MAXCALLS)             // handling overflow?
+        return;                                 // do not touch the stacks
     if (3 * ci_used < L->size_ci && 2 * BASIC_CI_SIZE < L->size_ci)
-        luaD_reallocCI(L, L->size_ci / 2); /* still big enough... */
+        luaD_reallocCI(L, L->size_ci / 2); // still big enough...
     condhardstacktests(luaD_reallocCI(L, ci_used + 1));
     if (3 * s_used < L->stacksize && 2 * (BASIC_STACK_SIZE + EXTRA_STACK) < L->stacksize)
-        luaD_reallocstack(L, L->stacksize / 2); /* still big enough... */
+        luaD_reallocstack(L, L->stacksize / 2); // still big enough...
     condhardstacktests(luaD_reallocstack(L, s_used));
 }
 
@@ -516,20 +516,20 @@ static void freeobj(lua_State* L, GCObject* o, lua_Page* page)
 static void shrinkbuffers(lua_State* L)
 {
     global_State* g = L->global;
-    /* check size of string hash */
+    // check size of string hash
     if (g->strt.nuse < cast_to(uint32_t, g->strt.size / 4) && g->strt.size > LUA_MINSTRTABSIZE * 2)
-        luaS_resize(L, g->strt.size / 2); /* table is too big */
+        luaS_resize(L, g->strt.size / 2); // table is too big
 }
 
 static void shrinkbuffersfull(lua_State* L)
 {
     global_State* g = L->global;
-    /* check size of string hash */
+    // check size of string hash
     int hashsize = g->strt.size;
     while (g->strt.nuse < cast_to(uint32_t, hashsize / 4) && hashsize > LUA_MINSTRTABSIZE * 2)
         hashsize /= 2;
     if (hashsize != g->strt.size)
-        luaS_resize(L, hashsize); /* table is too big */
+        luaS_resize(L, hashsize); // table is too big
 }
 
 static bool deletegco(void* context, lua_Page* page, GCObject* gco)
@@ -562,7 +562,7 @@ void luaC_freeall(lua_State* L)
 
     luaM_visitgco(L, L, deletegco);
 
-    for (int i = 0; i < g->strt.size; i++) /* free all string lists */
+    for (int i = 0; i < g->strt.size; i++) // free all string lists
         LUAU_ASSERT(g->strt.hash[i] == NULL);
 
     LUAU_ASSERT(L->global->strt.nuse == 0);
@@ -577,7 +577,7 @@ static void markmt(global_State* g)
             markobject(g, g->mt[i]);
 }
 
-/* mark root set */
+// mark root set
 static void markroot(lua_State* L)
 {
     global_State* g = L->global;
@@ -585,7 +585,7 @@ static void markroot(lua_State* L)
     g->grayagain = NULL;
     g->weak = NULL;
     markobject(g, g->mainthread);
-    /* make global table be traversed before main stack */
+    // make global table be traversed before main stack
     markobject(g, g->mainthread->gt);
     markvalue(g, registry(L));
     markmt(g);
@@ -616,28 +616,28 @@ static size_t atomic(lua_State* L)
     double currts = lua_clock();
 #endif
 
-    /* remark occasional upvalues of (maybe) dead threads */
+    // remark occasional upvalues of (maybe) dead threads
     work += remarkupvals(g);
-    /* traverse objects caught by write barrier and by 'remarkupvals' */
+    // traverse objects caught by write barrier and by 'remarkupvals'
     work += propagateall(g);
 
 #ifdef LUAI_GCMETRICS
     g->gcmetrics.currcycle.atomictimeupval += recordGcDeltaTime(currts);
 #endif
 
-    /* remark weak tables */
+    // remark weak tables
     g->gray = g->weak;
     g->weak = NULL;
     LUAU_ASSERT(!iswhite(obj2gco(g->mainthread)));
-    markobject(g, L); /* mark running thread */
-    markmt(g);        /* mark basic metatables (again) */
+    markobject(g, L); // mark running thread
+    markmt(g);        // mark basic metatables (again)
     work += propagateall(g);
 
 #ifdef LUAI_GCMETRICS
     g->gcmetrics.currcycle.atomictimeweak += recordGcDeltaTime(currts);
 #endif
 
-    /* remark gray again */
+    // remark gray again
     g->gray = g->grayagain;
     g->grayagain = NULL;
     work += propagateall(g);
@@ -646,7 +646,7 @@ static size_t atomic(lua_State* L)
     g->gcmetrics.currcycle.atomictimegray += recordGcDeltaTime(currts);
 #endif
 
-    /* remove collected objects from weak tables */
+    // remove collected objects from weak tables
     work += cleartable(L, g->weak);
     g->weak = NULL;
 
@@ -654,7 +654,7 @@ static size_t atomic(lua_State* L)
     g->gcmetrics.currcycle.atomictimeclear += recordGcDeltaTime(currts);
 #endif
 
-    /* flip current white */
+    // flip current white
     g->currentwhite = cast_byte(otherwhite(g));
     g->sweepgcopage = g->allgcopages;
     g->gcstate = GCSsweep;
@@ -733,7 +733,7 @@ static size_t gcstep(lua_State* L, size_t limit)
     {
     case GCSpause:
     {
-        markroot(L); /* start a new collection */
+        markroot(L); // start a new collection
         LUAU_ASSERT(g->gcstate == GCSpropagate);
         break;
     }
@@ -765,7 +765,7 @@ static size_t gcstep(lua_State* L, size_t limit)
             cost += propagatemark(g);
         }
 
-        if (!g->gray) /* no more `gray' objects */
+        if (!g->gray) // no more `gray' objects
         {
 #ifdef LUAI_GCMETRICS
             g->gcmetrics.currcycle.propagateagainwork =
@@ -786,7 +786,7 @@ static size_t gcstep(lua_State* L, size_t limit)
         g->gcstats.atomicstarttimestamp = lua_clock();
         g->gcstats.atomicstarttotalsizebytes = g->totalbytes;
 
-        cost = atomic(L); /* finish mark phase */
+        cost = atomic(L); // finish mark phase
 
         LUAU_ASSERT(g->gcstate == GCSsweep);
         break;
@@ -810,7 +810,7 @@ static size_t gcstep(lua_State* L, size_t limit)
             sweepgco(L, NULL, obj2gco(g->mainthread));
 
             shrinkbuffers(L);
-            g->gcstate = GCSpause; /* end collection */
+            g->gcstate = GCSpause; // end collection
         }
         break;
     }
@@ -878,7 +878,7 @@ size_t luaC_step(lua_State* L, bool assist)
 {
     global_State* g = L->global;
 
-    int lim = g->gcstepsize * g->gcstepmul / 100; /* how much to work */
+    int lim = g->gcstepsize * g->gcstepmul / 100; // how much to work
     LUAU_ASSERT(g->totalbytes >= g->GCthreshold);
     size_t debt = g->totalbytes - g->GCthreshold;
 
@@ -947,16 +947,16 @@ void luaC_fullgc(lua_State* L)
 
     if (g->gcstate <= GCSatomic)
     {
-        /* reset sweep marks to sweep all elements (returning them to white) */
+        // reset sweep marks to sweep all elements (returning them to white)
         g->sweepgcopage = g->allgcopages;
-        /* reset other collector lists */
+        // reset other collector lists
         g->gray = NULL;
         g->grayagain = NULL;
         g->weak = NULL;
         g->gcstate = GCSsweep;
     }
     LUAU_ASSERT(g->gcstate == GCSsweep);
-    /* finish any pending sweep phase */
+    // finish any pending sweep phase
     while (g->gcstate != GCSpause)
     {
         LUAU_ASSERT(g->gcstate == GCSsweep);
@@ -968,13 +968,13 @@ void luaC_fullgc(lua_State* L)
     startGcCycleMetrics(g);
 #endif
 
-    /* run a full collection cycle */
+    // run a full collection cycle
     markroot(L);
     while (g->gcstate != GCSpause)
     {
         gcstep(L, SIZE_MAX);
     }
-    /* reclaim as much buffer memory as possible (shrinkbuffers() called during sweep is incremental) */
+    // reclaim as much buffer memory as possible (shrinkbuffers() called during sweep is incremental)
     shrinkbuffersfull(L);
 
     size_t heapgoalsizebytes = (g->totalbytes / 100) * g->gcgoal;
@@ -1011,11 +1011,11 @@ void luaC_barrierf(lua_State* L, GCObject* o, GCObject* v)
     global_State* g = L->global;
     LUAU_ASSERT(isblack(o) && iswhite(v) && !isdead(g, v) && !isdead(g, o));
     LUAU_ASSERT(g->gcstate != GCSpause);
-    /* must keep invariant? */
+    // must keep invariant?
     if (keepinvariant(g))
-        reallymarkobject(g, v); /* restore invariant */
-    else                        /* don't mind */
-        makewhite(g, o);        /* mark as white just to avoid other barriers */
+        reallymarkobject(g, v); // restore invariant
+    else                        // don't mind
+        makewhite(g, o);        // mark as white just to avoid other barriers
 }
 
 void luaC_barriertable(lua_State* L, Table* t, GCObject* v)
@@ -1033,7 +1033,7 @@ void luaC_barriertable(lua_State* L, Table* t, GCObject* v)
 
     LUAU_ASSERT(isblack(o) && !isdead(g, o));
     LUAU_ASSERT(g->gcstate != GCSpause);
-    black2gray(o); /* make table gray (again) */
+    black2gray(o); // make table gray (again)
     t->gclist = g->grayagain;
     g->grayagain = o;
 }
@@ -1044,7 +1044,7 @@ void luaC_barrierback(lua_State* L, Table* t)
     GCObject* o = obj2gco(t);
     LUAU_ASSERT(isblack(o) && !isdead(g, o));
     LUAU_ASSERT(g->gcstate != GCSpause);
-    black2gray(o); /* make table gray (again) */
+    black2gray(o); // make table gray (again)
     t->gclist = g->grayagain;
     g->grayagain = o;
 }
@@ -1066,11 +1066,11 @@ void luaC_initupval(lua_State* L, UpVal* uv)
     {
         if (keepinvariant(g))
         {
-            gray2black(o); /* closed upvalues need barrier */
+            gray2black(o); // closed upvalues need barrier
             luaC_barrier(L, uv, uv->v);
         }
         else
-        { /* sweep phase: sweep it (turning it into white) */
+        { // sweep phase: sweep it (turning it into white)
             makewhite(g, o);
             LUAU_ASSERT(g->gcstate != GCSpause);
         }

VM/src/lgc.h

@@ -9,9 +9,9 @@
 /*
 ** Default settings for GC tunables (settable via lua_gc)
 */
-#define LUAI_GCGOAL 200    /* 200% (allow heap to double compared to live heap size) */
-#define LUAI_GCSTEPMUL 200 /* GC runs 'twice the speed' of memory allocation */
-#define LUAI_GCSTEPSIZE 1  /* GC runs every KB of memory allocation */
+#define LUAI_GCGOAL 200    // 200% (allow heap to double compared to live heap size)
+#define LUAI_GCSTEPMUL 200 // GC runs 'twice the speed' of memory allocation
+#define LUAI_GCSTEPSIZE 1  // GC runs every KB of memory allocation
 
 /*
 ** Possible states of the Garbage Collector

VM/src/lgcdebug.cpp

@@ -19,7 +19,7 @@ static void validateobjref(global_State* g, GCObject* f, GCObject* t)
 
     if (keepinvariant(g))
     {
-        /* basic incremental invariant: black can't point to white */
+        // basic incremental invariant: black can't point to white
         LUAU_ASSERT(!(isblack(f) && iswhite(t)));
     }
 }
@@ -135,7 +135,7 @@ static void validateproto(global_State* g, Proto* f)
 
 static void validateobj(global_State* g, GCObject* o)
 {
-    /* dead objects can only occur during sweep */
+    // dead objects can only occur during sweep
     if (isdead(g, o))
     {
         LUAU_ASSERT(g->gcstate == GCSsweep);

VM/src/lmathlib.cpp

@@ -195,7 +195,7 @@ static int math_ldexp(lua_State* L)
 
 static int math_min(lua_State* L)
 {
-    int n = lua_gettop(L); /* number of arguments */
+    int n = lua_gettop(L); // number of arguments
     double dmin = luaL_checknumber(L, 1);
     int i;
     for (i = 2; i <= n; i++)
@@ -210,7 +210,7 @@ static int math_min(lua_State* L)
 
 static int math_max(lua_State* L)
 {
-    int n = lua_gettop(L); /* number of arguments */
+    int n = lua_gettop(L); // number of arguments
     double dmax = luaL_checknumber(L, 1);
     int i;
     for (i = 2; i <= n; i++)
@@ -227,29 +227,29 @@ static int math_random(lua_State* L)
 {
     global_State* g = L->global;
     switch (lua_gettop(L))
-    { /* check number of arguments */
+    { // check number of arguments
     case 0:
-    { /* no arguments */
+    { // no arguments
         // Using ldexp instead of division for speed & clarity.
         // See http://mumble.net/~campbell/tmp/random_real.c for details on generating doubles from integer ranges.
         uint32_t rl = pcg32_random(&g->rngstate);
         uint32_t rh = pcg32_random(&g->rngstate);
         double rd = ldexp(double(rl | (uint64_t(rh) << 32)), -64);
-        lua_pushnumber(L, rd); /* number between 0 and 1 */
+        lua_pushnumber(L, rd); // number between 0 and 1
         break;
     }
     case 1:
-    { /* only upper limit */
+    { // only upper limit
         int u = luaL_checkinteger(L, 1);
         luaL_argcheck(L, 1 <= u, 1, "interval is empty");
 
         uint64_t x = uint64_t(u) * pcg32_random(&g->rngstate);
         int r = int(1 + (x >> 32));
-        lua_pushinteger(L, r); /* int between 1 and `u' */
+        lua_pushinteger(L, r); // int between 1 and `u'
         break;
     }
     case 2:
-    { /* lower and upper limits */
+    { // lower and upper limits
         int l = luaL_checkinteger(L, 1);
         int u = luaL_checkinteger(L, 2);
         luaL_argcheck(L, l <= u, 2, "interval is empty");
@@ -258,7 +258,7 @@ static int math_random(lua_State* L)
         luaL_argcheck(L, ul < UINT_MAX, 2, "interval is too large"); // -INT_MIN..INT_MAX interval can result in integer overflow
         uint64_t x = uint64_t(ul + 1) * pcg32_random(&g->rngstate);
         int r = int(l + (x >> 32));
-        lua_pushinteger(L, r); /* int between `l' and `u' */
+        lua_pushinteger(L, r); // int between `l' and `u'
         break;
     }
     default:

VM/src/lnumutils.h

@@ -42,7 +42,7 @@ LUAU_FASTMATH_END
 
 #define luai_num2int(i, d) ((i) = (int)(d))
 
-/* On MSVC in 32-bit, double to unsigned cast compiles into a call to __dtoui3, so we invoke x87->int64 conversion path manually */
+// On MSVC in 32-bit, double to unsigned cast compiles into a call to __dtoui3, so we invoke x87->int64 conversion path manually
 #if defined(_MSC_VER) && defined(_M_IX86)
 #define luai_num2unsigned(i, n) \
     { \

VM/src/lobject.cpp

@@ -48,7 +48,7 @@ int luaO_rawequalObj(const TValue* t1, const TValue* t2)
         case LUA_TVECTOR:
             return luai_veceq(vvalue(t1), vvalue(t2));
         case LUA_TBOOLEAN:
-            return bvalue(t1) == bvalue(t2); /* boolean true must be 1 !! */
+            return bvalue(t1) == bvalue(t2); // boolean true must be 1 !!
         case LUA_TLIGHTUSERDATA:
             return pvalue(t1) == pvalue(t2);
         default:
@@ -71,7 +71,7 @@ int luaO_rawequalKey(const TKey* t1, const TValue* t2)
         case LUA_TVECTOR:
             return luai_veceq(vvalue(t1), vvalue(t2));
         case LUA_TBOOLEAN:
-            return bvalue(t1) == bvalue(t2); /* boolean true must be 1 !! */
+            return bvalue(t1) == bvalue(t2); // boolean true must be 1 !!
         case LUA_TLIGHTUSERDATA:
             return pvalue(t1) == pvalue(t2);
         default:
@@ -85,15 +85,15 @@ int luaO_str2d(const char* s, double* result)
     char* endptr;
     *result = luai_str2num(s, &endptr);
     if (endptr == s)
-        return 0;                         /* conversion failed */
-    if (*endptr == 'x' || *endptr == 'X') /* maybe an hexadecimal constant? */
+        return 0;                         // conversion failed
+    if (*endptr == 'x' || *endptr == 'X') // maybe an hexadecimal constant?
         *result = cast_num(strtoul(s, &endptr, 16));
     if (*endptr == '\0')
-        return 1; /* most common case */
+        return 1; // most common case
     while (isspace(cast_to(unsigned char, *endptr)))
         endptr++;
     if (*endptr != '\0')
-        return 0; /* invalid trailing characters? */
+        return 0; // invalid trailing characters?
     return 1;
 }
 
@@ -121,7 +121,7 @@ void luaO_chunkid(char* out, const char* source, size_t bufflen)
 {
     if (*source == '=')
     {
-        source++; /* skip the `=' */
+        source++; // skip the `='
         size_t srclen = strlen(source);
         size_t dstlen = srclen < bufflen ? srclen : bufflen - 1;
         memcpy(out, source, dstlen);
@@ -130,26 +130,26 @@ void luaO_chunkid(char* out, const char* source, size_t bufflen)
     else if (*source == '@')
     {
         size_t l;
-        source++; /* skip the `@' */
+        source++; // skip the `@'
         bufflen -= sizeof("...");
         l = strlen(source);
         strcpy(out, "");
         if (l > bufflen)
         {
-            source += (l - bufflen); /* get last part of file name */
+            source += (l - bufflen); // get last part of file name
             strcat(out, "...");
         }
         strcat(out, source);
     }
     else
-    {                                         /* out = [string "string"] */
-        size_t len = strcspn(source, "\n\r"); /* stop at first newline */
+    {                                         // out = [string "string"]
+        size_t len = strcspn(source, "\n\r"); // stop at first newline
         bufflen -= sizeof("[string \"...\"]");
         if (len > bufflen)
             len = bufflen;
         strcpy(out, "[string \"");
         if (source[len] != '\0')
-        { /* must truncate? */
+        { // must truncate?
             strncat(out, source, len);
             strcat(out, "...");
         }

VM/src/lobject.h

@@ -49,7 +49,7 @@ typedef struct lua_TValue
     int tt;
 } TValue;
 
-/* Macros to test type */
+// Macros to test type
 #define ttisnil(o) (ttype(o) == LUA_TNIL)
 #define ttisnumber(o) (ttype(o) == LUA_TNUMBER)
 #define ttisstring(o) (ttype(o) == LUA_TSTRING)
@@ -62,7 +62,7 @@ typedef struct lua_TValue
 #define ttisvector(o) (ttype(o) == LUA_TVECTOR)
 #define ttisupval(o) (ttype(o) == LUA_TUPVAL)
 
-/* Macros to access values */
+// Macros to access values
 #define ttype(o) ((o)->tt)
 #define gcvalue(o) check_exp(iscollectable(o), (o)->value.gc)
 #define pvalue(o) check_exp(ttislightuserdata(o), (o)->value.p)
@@ -85,7 +85,7 @@ typedef struct lua_TValue
 
 #define checkliveness(g, obj) LUAU_ASSERT(!iscollectable(obj) || ((ttype(obj) == (obj)->value.gc->gch.tt) && !isdead(g, (obj)->value.gc)))
 
-/* Macros to set values */
+// Macros to set values
 #define setnilvalue(obj) ((obj)->tt = LUA_TNIL)
 
 #define setnvalue(obj, x) \
@@ -200,18 +200,18 @@ typedef struct lua_TValue
 ** different types of sets, according to destination
 */
 
-/* from stack to (same) stack */
+// from stack to (same) stack
 #define setobjs2s setobj
-/* to stack (not from same stack) */
+// to stack (not from same stack)
 #define setobj2s setobj
 #define setsvalue2s setsvalue
 #define sethvalue2s sethvalue
 #define setptvalue2s setptvalue
-/* from table to same table */
+// from table to same table
 #define setobjt2t setobj
-/* to table */
+// to table
 #define setobj2t setobj
-/* to new object */
+// to new object
 #define setobj2n setobj
 #define setsvalue2n setsvalue
 
@@ -219,7 +219,7 @@ typedef struct lua_TValue
 
 #define iscollectable(o) (ttype(o) >= LUA_TSTRING)
 
-typedef TValue* StkId; /* index to stack elements */
+typedef TValue* StkId; // index to stack elements
 
 /*
 ** String headers for string table
@@ -269,13 +269,13 @@ typedef struct Proto
     CommonHeader;
 
 
-    TValue* k;              /* constants used by the function */
-    Instruction* code;      /* function bytecode */
-    struct Proto** p;       /* functions defined inside the function */
-    uint8_t* lineinfo;      /* for each instruction, line number as a delta from baseline */
-    int* abslineinfo;       /* baseline line info, one entry for each 1<<linegaplog2 instructions; allocated after lineinfo */
-    struct LocVar* locvars; /* information about local variables */
-    TString** upvalues;     /* upvalue names */
+    TValue* k;              // constants used by the function
+    Instruction* code;      // function bytecode
+    struct Proto** p;       // functions defined inside the function
+    uint8_t* lineinfo;      // for each instruction, line number as a delta from baseline
+    int* abslineinfo;       // baseline line info, one entry for each 1<<linegaplog2 instructions; allocated after lineinfo
+    struct LocVar* locvars; // information about local variables
+    TString** upvalues;     // upvalue names
     TString* source;
 
     TString* debugname;
@@ -294,7 +294,7 @@ typedef struct Proto
     int linedefined;
 
 
-    uint8_t nups; /* number of upvalues */
+    uint8_t nups; // number of upvalues
     uint8_t numparams;
     uint8_t is_vararg;
     uint8_t maxstacksize;
@@ -304,9 +304,9 @@ typedef struct Proto
 typedef struct LocVar
 {
     TString* varname;
-    int startpc; /* first point where variable is active */
-    int endpc;   /* first point where variable is dead */
-    uint8_t reg; /* register slot, relative to base, where variable is stored */
+    int startpc; // first point where variable is active
+    int endpc;   // first point where variable is dead
+    uint8_t reg; // register slot, relative to base, where variable is stored
 } LocVar;
 
 /*
@@ -317,19 +317,19 @@ typedef struct UpVal
 {
     CommonHeader;
     // 1 (x86) or 5 (x64) byte padding
-    TValue* v; /* points to stack or to its own value */
+    TValue* v; // points to stack or to its own value
     union
     {
-        TValue value; /* the value (when closed) */
+        TValue value; // the value (when closed)
         struct
         {
-            /* global double linked list (when open) */
+            // global double linked list (when open)
             struct UpVal* prev;
             struct UpVal* next;
 
-            /* thread double linked list (when open) */
+            // thread double linked list (when open)
             struct UpVal* threadnext;
-            /* note: this is the location of a pointer to this upvalue in the previous element that can be either an UpVal or a lua_State */
+            // note: this is the location of a pointer to this upvalue in the previous element that can be either an UpVal or a lua_State
             struct UpVal** threadprev;
         } l;
     } u;
@@ -381,7 +381,7 @@ typedef struct TKey
     ::Value value;
     int extra[LUA_EXTRA_SIZE];
     unsigned tt : 4;
-    int next : 28; /* for chaining */
+    int next : 28; // for chaining
 } TKey;
 
 typedef struct LuaNode
@@ -390,7 +390,7 @@ typedef struct LuaNode
     TKey key;
 } LuaNode;
 
-/* copy a value into a key */
+// copy a value into a key
 #define setnodekey(L, node, obj) \
     { \
         LuaNode* n_ = (node); \
@@ -401,7 +401,7 @@ typedef struct LuaNode
         checkliveness(L->global, i_o); \
     }
 
-/* copy a value from a key */
+// copy a value from a key
 #define getnodekey(L, obj, node) \
     { \
         TValue* i_o = (obj); \
@@ -418,22 +418,22 @@ typedef struct Table
     CommonHeader;
 
 
-    uint8_t tmcache;    /* 1<<p means tagmethod(p) is not present */
-    uint8_t readonly;   /* sandboxing feature to prohibit writes to table */
-    uint8_t safeenv;    /* environment doesn't share globals with other scripts */
-    uint8_t lsizenode;  /* log2 of size of `node' array */
-    uint8_t nodemask8; /* (1<<lsizenode)-1, truncated to 8 bits */
+    uint8_t tmcache;    // 1<<p means tagmethod(p) is not present
+    uint8_t readonly;   // sandboxing feature to prohibit writes to table
+    uint8_t safeenv;    // environment doesn't share globals with other scripts
+    uint8_t lsizenode;  // log2 of size of `node' array
+    uint8_t nodemask8; // (1<<lsizenode)-1, truncated to 8 bits
 
-    int sizearray; /* size of `array' array */
+    int sizearray; // size of `array' array
     union
     {
-        int lastfree;  /* any free position is before this position */
-        int aboundary; /* negated 'boundary' of `array' array; iff aboundary < 0 */
+        int lastfree;  // any free position is before this position
+        int aboundary; // negated 'boundary' of `array' array; iff aboundary < 0
     };
 
 
     struct Table* metatable;
-    TValue* array;  /* array part */
+    TValue* array;  // array part
     LuaNode* node;
     GCObject* gclist;
 } Table;

VM/src/loslib.cpp

@@ -46,8 +46,8 @@ static void setfield(lua_State* L, const char* key, int value)
 
 static void setboolfield(lua_State* L, const char* key, int value)
 {
-    if (value < 0) /* undefined? */
-        return;    /* does not set field */
+    if (value < 0) // undefined?
+        return;    // does not set field
     lua_pushboolean(L, value);
     lua_setfield(L, -2, key);
 }
@@ -85,9 +85,9 @@ static int os_date(lua_State* L)
     struct tm tm;
     struct tm* stm;
     if (*s == '!')
-    { /* UTC? */
+    { // UTC?
         stm = gmtime_r(&t, &tm);
-        s++; /* skip `!' */
+        s++; // skip `!'
     }
     else
     {
@@ -95,13 +95,13 @@ static int os_date(lua_State* L)
         stm = t < 0 ? NULL : localtime_r(&t, &tm);
     }
 
-    if (stm == NULL) /* invalid date? */
+    if (stm == NULL) // invalid date?
     {
         lua_pushnil(L);
     }
     else if (strcmp(s, "*t") == 0)
     {
-        lua_createtable(L, 0, 9); /* 9 = number of fields */
+        lua_createtable(L, 0, 9); // 9 = number of fields
         setfield(L, "sec", stm->tm_sec);
         setfield(L, "min", stm->tm_min);
         setfield(L, "hour", stm->tm_hour);
@@ -122,7 +122,7 @@ static int os_date(lua_State* L)
         luaL_buffinit(L, &b);
         for (; *s; s++)
         {
-            if (*s != '%' || *(s + 1) == '\0') /* no conversion specifier? */
+            if (*s != '%' || *(s + 1) == '\0') // no conversion specifier?
             {
                 luaL_addchar(&b, *s);
             }
@@ -133,7 +133,7 @@ static int os_date(lua_State* L)
             else
             {
                 size_t reslen;
-                char buff[200]; /* should be big enough for any conversion result */
+                char buff[200]; // should be big enough for any conversion result
                 cc[1] = *(++s);
                 reslen = strftime(buff, sizeof(buff), cc, stm);
                 luaL_addlstring(&b, buff, reslen);
@@ -147,13 +147,13 @@ static int os_date(lua_State* L)
 static int os_time(lua_State* L)
 {
     time_t t;
-    if (lua_isnoneornil(L, 1)) /* called without args? */
-        t = time(NULL);        /* get current time */
+    if (lua_isnoneornil(L, 1)) // called without args?
+        t = time(NULL);        // get current time
     else
     {
         struct tm ts;
         luaL_checktype(L, 1, LUA_TTABLE);
-        lua_settop(L, 1); /* make sure table is at the top */
+        lua_settop(L, 1); // make sure table is at the top
         ts.tm_sec = getfield(L, "sec", 0);
         ts.tm_min = getfield(L, "min", 0);
         ts.tm_hour = getfield(L, "hour", 12);

VM/src/lstate.cpp

@@ -21,22 +21,22 @@ typedef struct LG
 
 static void stack_init(lua_State* L1, lua_State* L)
 {
-    /* initialize CallInfo array */
+    // initialize CallInfo array
     L1->base_ci = luaM_newarray(L, BASIC_CI_SIZE, CallInfo, L1->memcat);
     L1->ci = L1->base_ci;
     L1->size_ci = BASIC_CI_SIZE;
     L1->end_ci = L1->base_ci + L1->size_ci - 1;
-    /* initialize stack array */
+    // initialize stack array
     L1->stack = luaM_newarray(L, BASIC_STACK_SIZE + EXTRA_STACK, TValue, L1->memcat);
     L1->stacksize = BASIC_STACK_SIZE + EXTRA_STACK;
     TValue* stack = L1->stack;
     for (int i = 0; i < BASIC_STACK_SIZE + EXTRA_STACK; i++)
-        setnilvalue(stack + i); /* erase new stack */
+        setnilvalue(stack + i); // erase new stack
     L1->top = stack;
     L1->stack_last = stack + (L1->stacksize - EXTRA_STACK);
-    /* initialize first ci */
+    // initialize first ci
     L1->ci->func = L1->top;
-    setnilvalue(L1->top++); /* `function' entry for this `ci' */
+    setnilvalue(L1->top++); // `function' entry for this `ci'
     L1->base = L1->ci->base = L1->top;
     L1->ci->top = L1->top + LUA_MINSTACK;
 }
@@ -53,13 +53,13 @@ static void freestack(lua_State* L, lua_State* L1)
 static void f_luaopen(lua_State* L, void* ud)
 {
     global_State* g = L->global;
-    stack_init(L, L);                             /* init stack */
-    L->gt = luaH_new(L, 0, 2);                    /* table of globals */
-    sethvalue(L, registry(L), luaH_new(L, 0, 2)); /* registry */
-    luaS_resize(L, LUA_MINSTRTABSIZE);            /* initial size of string table */
+    stack_init(L, L);                             // init stack
+    L->gt = luaH_new(L, 0, 2);                    // table of globals
+    sethvalue(L, registry(L), luaH_new(L, 0, 2)); // registry
+    luaS_resize(L, LUA_MINSTRTABSIZE);            // initial size of string table
     luaT_init(L);
-    luaS_fix(luaS_newliteral(L, LUA_MEMERRMSG)); /* pin to make sure we can always throw this error */
-    luaS_fix(luaS_newliteral(L, LUA_ERRERRMSG)); /* pin to make sure we can always throw this error */
+    luaS_fix(luaS_newliteral(L, LUA_MEMERRMSG)); // pin to make sure we can always throw this error
+    luaS_fix(luaS_newliteral(L, LUA_ERRERRMSG)); // pin to make sure we can always throw this error
     g->GCthreshold = 4 * g->totalbytes;
 }
 
@@ -85,8 +85,8 @@ static void preinit_state(lua_State* L, global_State* g)
 static void close_state(lua_State* L)
 {
     global_State* g = L->global;
-    luaF_close(L, L->stack); /* close all upvalues for this thread */
-    luaC_freeall(L);         /* collect all objects */
+    luaF_close(L, L->stack); // close all upvalues for this thread
+    luaC_freeall(L);         // collect all objects
     LUAU_ASSERT(g->strbufgc == NULL);
     LUAU_ASSERT(g->strt.nuse == 0);
     luaM_freearray(L, L->global->strt.hash, L->global->strt.size, TString*, 0);
@@ -110,8 +110,8 @@ lua_State* luaE_newthread(lua_State* L)
     luaC_init(L, L1, LUA_TTHREAD);
     preinit_state(L1, L->global);
     L1->activememcat = L->activememcat; // inherit the active memory category
-    stack_init(L1, L);                  /* init stack */
-    L1->gt = L->gt;                     /* share table of globals */
+    stack_init(L1, L);                  // init stack
+    L1->gt = L->gt;                     // share table of globals
     L1->singlestep = L->singlestep;
     LUAU_ASSERT(iswhite(obj2gco(L1)));
     return L1;
@@ -119,7 +119,7 @@ lua_State* luaE_newthread(lua_State* L)
 
 void luaE_freethread(lua_State* L, lua_State* L1, lua_Page* page)
 {
-    luaF_close(L1, L1->stack); /* close all upvalues for this thread */
+    luaF_close(L1, L1->stack); // close all upvalues for this thread
     LUAU_ASSERT(L1->openupval == NULL);
     global_State* g = L->global;
     if (g->cb.userthread)
@@ -130,9 +130,9 @@ void luaE_freethread(lua_State* L, lua_State* L1, lua_Page* page)
 
 void lua_resetthread(lua_State* L)
 {
-    /* close upvalues before clearing anything */
+    // close upvalues before clearing anything
     luaF_close(L, L->stack);
-    /* clear call frames */
+    // clear call frames
     CallInfo* ci = L->base_ci;
     ci->func = L->stack;
     ci->base = ci->func + 1;
@@ -141,12 +141,12 @@ void lua_resetthread(lua_State* L)
     L->ci = ci;
     if (L->size_ci != BASIC_CI_SIZE)
         luaD_reallocCI(L, BASIC_CI_SIZE);
-    /* clear thread state */
+    // clear thread state
     L->status = LUA_OK;
     L->base = L->ci->base;
     L->top = L->ci->base;
     L->nCcalls = L->baseCcalls = 0;
-    /* clear thread stack */
+    // clear thread stack
     if (L->stacksize != BASIC_STACK_SIZE + EXTRA_STACK)
         luaD_reallocstack(L, BASIC_STACK_SIZE);
     for (int i = 0; i < L->stacksize; i++)
@@ -177,7 +177,7 @@ lua_State* lua_newstate(lua_Alloc f, void* ud)
     g->mainthread = L;
     g->uvhead.u.l.prev = &g->uvhead;
     g->uvhead.u.l.next = &g->uvhead;
-    g->GCthreshold = 0; /* mark it as unfinished state */
+    g->GCthreshold = 0; // mark it as unfinished state
     g->registryfree = 0;
     g->errorjmp = NULL;
     g->rngstate = 0;
@@ -224,7 +224,7 @@ lua_State* lua_newstate(lua_Alloc f, void* ud)
 
     if (luaD_rawrunprotected(L, f_luaopen, NULL) != 0)
     {
-        /* memory allocation error: free partial state */
+        // memory allocation error: free partial state
         close_state(L);
         L = NULL;
     }
@@ -233,7 +233,7 @@ lua_State* lua_newstate(lua_Alloc f, void* ud)
 
 void lua_close(lua_State* L)
 {
-    L = L->global->mainthread; /* only the main thread can be closed */
-    luaF_close(L, L->stack);   /* close all upvalues for this thread */
+    L = L->global->mainthread; // only the main thread can be closed
+    luaF_close(L, L->stack);   // close all upvalues for this thread
     close_state(L);
 }

VM/src/lstate.h

@@ -5,10 +5,10 @@
 #include "lobject.h"
 #include "ltm.h"
 
-/* registry */
+// registry
 #define registry(L) (&L->global->registry)
 
-/* extra stack space to handle TM calls and some other extras */
+// extra stack space to handle TM calls and some other extras
 #define EXTRA_STACK 5
 
 #define BASIC_CI_SIZE 8
@@ -20,7 +20,7 @@ typedef struct stringtable
 {
 
     TString** hash;
-    uint32_t nuse; /* number of elements */
+    uint32_t nuse; // number of elements
     int size;
 } stringtable;
 // clang-format on
@@ -57,18 +57,18 @@ typedef struct stringtable
 typedef struct CallInfo
 {
 
-    StkId base;    /* base for this function */
-    StkId func;    /* function index in the stack */
-    StkId top;     /* top for this function */
+    StkId base;    // base for this function
+    StkId func;    // function index in the stack
+    StkId top;     // top for this function
     const Instruction* savedpc;
 
-    int nresults;       /* expected number of results from this function */
-    unsigned int flags; /* call frame flags, see LUA_CALLINFO_* */
+    int nresults;       // expected number of results from this function
+    unsigned int flags; // call frame flags, see LUA_CALLINFO_*
 } CallInfo;
 // clang-format on
 
-#define LUA_CALLINFO_RETURN (1 << 0) /* should the interpreter return after returning from this callinfo? first frame must have this set */
-#define LUA_CALLINFO_HANDLE (1 << 1) /* should the error thrown during execution get handled by continuation from this callinfo? func must be C */
+#define LUA_CALLINFO_RETURN (1 << 0) // should the interpreter return after returning from this callinfo? first frame must have this set
+#define LUA_CALLINFO_HANDLE (1 << 1) // should the error thrown during execution get handled by continuation from this callinfo? func must be C
 
 #define curr_func(L) (clvalue(L->ci->func))
 #define ci_func(ci) (clvalue((ci)->func))
@@ -152,55 +152,55 @@ struct GCMetrics
 // clang-format off
 typedef struct global_State
 {
-    stringtable strt; /* hash table for strings */
+    stringtable strt; // hash table for strings
 
 
-    lua_Alloc frealloc;   /* function to reallocate memory */
-    void* ud;            /* auxiliary data to `frealloc' */
+    lua_Alloc frealloc;   // function to reallocate memory
+    void* ud;            // auxiliary data to `frealloc'
 
 
     uint8_t currentwhite;
-    uint8_t gcstate; /* state of garbage collector */
+    uint8_t gcstate; // state of garbage collector
 
 
-    GCObject* gray;      /* list of gray objects */
-    GCObject* grayagain; /* list of objects to be traversed atomically */
-    GCObject* weak;     /* list of weak tables (to be cleared) */
+    GCObject* gray;      // list of gray objects
+    GCObject* grayagain; // list of objects to be traversed atomically
+    GCObject* weak;     // list of weak tables (to be cleared)
 
     TString* strbufgc; // list of all string buffer objects
 
 
-    size_t GCthreshold;                       // when totalbytes > GCthreshold; run GC step
+    size_t GCthreshold;                       // when totalbytes > GCthreshold, run GC step
     size_t totalbytes;                        // number of bytes currently allocated
     int gcgoal;                               // see LUAI_GCGOAL
     int gcstepmul;                            // see LUAI_GCSTEPMUL
     int gcstepsize;                          // see LUAI_GCSTEPSIZE
 
     struct lua_Page* freepages[LUA_SIZECLASSES]; // free page linked list for each size class for non-collectable objects
-    struct lua_Page* freegcopages[LUA_SIZECLASSES]; // free page linked list for each size class for collectable objects 
+    struct lua_Page* freegcopages[LUA_SIZECLASSES]; // free page linked list for each size class for collectable objects
     struct lua_Page* allgcopages; // page linked list with all pages for all classes
     struct lua_Page* sweepgcopage; // position of the sweep in `allgcopages'
 
-    size_t memcatbytes[LUA_MEMORY_CATEGORIES]; /* total amount of memory used by each memory category */
+    size_t memcatbytes[LUA_MEMORY_CATEGORIES]; // total amount of memory used by each memory category
 
 
     struct lua_State* mainthread;
-    UpVal uvhead;                                    /* head of double-linked list of all open upvalues */
-    struct Table* mt[LUA_T_COUNT];                   /* metatables for basic types */
-    TString* ttname[LUA_T_COUNT];       /* names for basic types */
-    TString* tmname[TM_N];             /* array with tag-method names */
+    UpVal uvhead;                                    // head of double-linked list of all open upvalues
+    struct Table* mt[LUA_T_COUNT];                   // metatables for basic types
+    TString* ttname[LUA_T_COUNT];       // names for basic types
+    TString* tmname[TM_N];             // array with tag-method names
 
-    TValue pseudotemp; /* storage for temporary values used in pseudo2addr */
+    TValue pseudotemp; // storage for temporary values used in pseudo2addr
 
-    TValue registry; /* registry table, used by lua_ref and LUA_REGISTRYINDEX */
-    int registryfree; /* next free slot in registry */
+    TValue registry; // registry table, used by lua_ref and LUA_REGISTRYINDEX
+    int registryfree; // next free slot in registry
 
-    struct lua_jmpbuf* errorjmp; /* jump buffer data for longjmp-style error handling */
+    struct lua_jmpbuf* errorjmp; // jump buffer data for longjmp-style error handling
 
-    uint64_t rngstate; /* PCG random number generator state */
-    uint64_t ptrenckey[4]; /* pointer encoding key for display */
+    uint64_t rngstate; // PCG random number generator state
+    uint64_t ptrenckey[4]; // pointer encoding key for display
 
-    void (*udatagc[LUA_UTAG_LIMIT])(lua_State*, void*); /* for each userdata tag, a gc callback to be called immediately before freeing memory */
+    void (*udatagc[LUA_UTAG_LIMIT])(lua_State*, void*); // for each userdata tag, a gc callback to be called immediately before freeing memory
 
     lua_Callbacks cb;
 
@@ -221,39 +221,39 @@ struct lua_State
     CommonHeader;
     uint8_t status;
 
-    uint8_t activememcat; /* memory category that is used for new GC object allocations */
+    uint8_t activememcat; // memory category that is used for new GC object allocations
     uint8_t stackstate;
 
-    bool singlestep; /* call debugstep hook after each instruction */
+    bool singlestep; // call debugstep hook after each instruction
 
 
-    StkId top;                                        /* first free slot in the stack */
-    StkId base;                                       /* base of current function */
+    StkId top;                                        // first free slot in the stack
+    StkId base;                                       // base of current function
     global_State* global;
-    CallInfo* ci;                                     /* call info for current function */
-    StkId stack_last;                                 /* last free slot in the stack */
-    StkId stack;                                     /* stack base */
+    CallInfo* ci;                                     // call info for current function
+    StkId stack_last;                                 // last free slot in the stack
+    StkId stack;                                     // stack base
 
 
-    CallInfo* end_ci;                          /* points after end of ci array*/
-    CallInfo* base_ci;                        /* array of CallInfo's */
+    CallInfo* end_ci;                          // points after end of ci array
+    CallInfo* base_ci;                        // array of CallInfo's
 
 
     int stacksize;
-    int size_ci;                              /* size of array `base_ci' */
+    int size_ci;                              // size of array `base_ci'
 
 
-    unsigned short nCcalls;     /* number of nested C calls */
-    unsigned short baseCcalls; /* nested C calls when resuming coroutine */
+    unsigned short nCcalls;     // number of nested C calls
+    unsigned short baseCcalls; // nested C calls when resuming coroutine
 
-    int cachedslot;    /* when table operations or INDEX/NEWINDEX is invoked from Luau, what is the expected slot for lookup? */
+    int cachedslot;    // when table operations or INDEX/NEWINDEX is invoked from Luau, what is the expected slot for lookup?
 
 
-    Table* gt;           /* table of globals */
-    UpVal* openupval;    /* list of open upvalues in this stack */
+    Table* gt;           // table of globals
+    UpVal* openupval;    // list of open upvalues in this stack
     GCObject* gclist;
 
-    TString* namecall; /* when invoked from Luau using NAMECALL, what method do we need to invoke? */
+    TString* namecall; // when invoked from Luau using NAMECALL, what method do we need to invoke?
 
     void* userdata;
 };
@@ -271,10 +271,10 @@ union GCObject
     struct Table h;
     struct Proto p;
     struct UpVal uv;
-    struct lua_State th; /* thread */
+    struct lua_State th; // thread
 };
 
-/* macros to convert a GCObject into a specific value */
+// macros to convert a GCObject into a specific value
 #define gco2ts(o) check_exp((o)->gch.tt == LUA_TSTRING, &((o)->ts))
 #define gco2u(o) check_exp((o)->gch.tt == LUA_TUSERDATA, &((o)->u))
 #define gco2cl(o) check_exp((o)->gch.tt == LUA_TFUNCTION, &((o)->cl))
@@ -283,7 +283,7 @@ union GCObject
 #define gco2uv(o) check_exp((o)->gch.tt == LUA_TUPVAL, &((o)->uv))
 #define gco2th(o) check_exp((o)->gch.tt == LUA_TTHREAD, &((o)->th))
 
-/* macro to convert any Lua object into a GCObject */
+// macro to convert any Lua object into a GCObject
 #define obj2gco(v) check_exp(iscollectable(v), cast_to(GCObject*, (v) + 0))
 
 LUAI_FUNC lua_State* luaE_newthread(lua_State* L);

VM/src/lstring.cpp

@@ -48,17 +48,17 @@ void luaS_resize(lua_State* L, int newsize)
     stringtable* tb = &L->global->strt;
     for (int i = 0; i < newsize; i++)
         newhash[i] = NULL;
-    /* rehash */
+    // rehash
     for (int i = 0; i < tb->size; i++)
     {
         TString* p = tb->hash[i];
         while (p)
-        {                            /* for each node in the list */
-            TString* next = p->next; /* save next */
+        {                            // for each node in the list
+            TString* next = p->next; // save next
             unsigned int h = p->hash;
-            int h1 = lmod(h, newsize); /* new position */
+            int h1 = lmod(h, newsize); // new position
             LUAU_ASSERT(cast_int(h % newsize) == lmod(h, newsize));
-            p->next = newhash[h1]; /* chain it */
+            p->next = newhash[h1]; // chain it
             newhash[h1] = p;
             p = next;
         }
@@ -81,15 +81,15 @@ static TString* newlstr(lua_State* L, const char* str, size_t l, unsigned int h)
     ts->tt = LUA_TSTRING;
     ts->memcat = L->activememcat;
     memcpy(ts->data, str, l);
-    ts->data[l] = '\0'; /* ending 0 */
+    ts->data[l] = '\0'; // ending 0
     ts->atom = ATOM_UNDEF;
     tb = &L->global->strt;
     h = lmod(h, tb->size);
-    ts->next = tb->hash[h]; /* chain new entry */
+    ts->next = tb->hash[h]; // chain new entry
     tb->hash[h] = ts;
     tb->nuse++;
     if (tb->nuse > cast_to(uint32_t, tb->size) && tb->size <= INT_MAX / 2)
-        luaS_resize(L, tb->size * 2); /* too crowded */
+        luaS_resize(L, tb->size * 2); // too crowded
     return ts;
 }
 
@@ -181,13 +181,13 @@ TString* luaS_newlstr(lua_State* L, const char* str, size_t l)
     {
         if (el->len == l && (memcmp(str, getstr(el), l) == 0))
         {
-            /* string may be dead */
+            // string may be dead
             if (isdead(L->global, obj2gco(el)))
                 changewhite(obj2gco(el));
             return el;
         }
     }
-    return newlstr(L, str, l, h); /* not found */
+    return newlstr(L, str, l, h); // not found
 }
 
 static bool unlinkstr(lua_State* L, TString* ts)

VM/src/lstring.h

@@ -5,10 +5,10 @@
 #include "lobject.h"
 #include "lstate.h"
 
-/* string size limit */
+// string size limit
 #define MAXSSIZE (1 << 30)
 
-/* string atoms are not defined by default; the storage is 16-bit integer */
+// string atoms are not defined by default; the storage is 16-bit integer
 #define ATOM_UNDEF -32768
 
 #define sizestring(len) (offsetof(TString, data) + len + 1)

VM/src/lstrlib.cpp

@@ -10,7 +10,7 @@
 
 LUAU_FASTFLAGVARIABLE(LuauTostringFormatSpecifier, false);
 
-/* macro to `unsign' a character */
+// macro to `unsign' a character
 #define uchar(c) ((unsigned char)(c))
 
 static int str_len(lua_State* L)
@@ -23,7 +23,7 @@ static int str_len(lua_State* L)
 
 static int posrelat(int pos, size_t len)
 {
-    /* relative string position: negative means back from end */
+    // relative string position: negative means back from end
     if (pos < 0)
         pos += (int)len + 1;
     return (pos >= 0) ? pos : 0;
@@ -139,9 +139,9 @@ static int str_byte(lua_State* L)
     if ((size_t)pose > l)
         pose = (int)l;
     if (posi > pose)
-        return 0; /* empty interval; return no values */
+        return 0; // empty interval; return no values
     n = (int)(pose - posi + 1);
-    if (posi + n <= pose) /* overflow? */
+    if (posi + n <= pose) // overflow?
         luaL_error(L, "string slice too long");
     luaL_checkstack(L, n, "string slice too long");
     for (i = 0; i < n; i++)
@@ -151,7 +151,7 @@ static int str_byte(lua_State* L)
 
 static int str_char(lua_State* L)
 {
-    int n = lua_gettop(L); /* number of arguments */
+    int n = lua_gettop(L); // number of arguments
 
     luaL_Buffer b;
     char* ptr = luaL_buffinitsize(L, &b, n);
@@ -178,12 +178,12 @@ static int str_char(lua_State* L)
 
 typedef struct MatchState
 {
-    int matchdepth;       /* control for recursive depth (to avoid C stack overflow) */
-    const char* src_init; /* init of source string */
-    const char* src_end;  /* end ('\0') of source string */
-    const char* p_end;    /* end ('\0') of pattern */
+    int matchdepth;       // control for recursive depth (to avoid C stack overflow)
+    const char* src_init; // init of source string
+    const char* src_end;  // end ('\0') of source string
+    const char* p_end;    // end ('\0') of pattern
     lua_State* L;
-    int level; /* total number of captures (finished or unfinished) */
+    int level; // total number of captures (finished or unfinished)
     struct
     {
         const char* init;
@@ -191,7 +191,7 @@ typedef struct MatchState
     } capture[LUA_MAXCAPTURES];
 } MatchState;
 
-/* recursive function */
+// recursive function
 static const char* match(MatchState* ms, const char* s, const char* p);
 
 #define L_ESC '%'
@@ -229,11 +229,11 @@ static const char* classend(MatchState* ms, const char* p)
         if (*p == '^')
             p++;
         do
-        { /* look for a `]' */
+        { // look for a `]'
             if (p == ms->p_end)
                 luaL_error(ms->L, "malformed pattern (missing ']')");
             if (*(p++) == L_ESC && p < ms->p_end)
-                p++; /* skip escapes (e.g. `%]') */
+                p++; // skip escapes (e.g. `%]')
         } while (*p != ']');
         return p + 1;
     }
@@ -281,7 +281,7 @@ static int match_class(int c, int cl)
         break;
     case 'z':
         res = (c == 0);
-        break; /* deprecated option */
+        break; // deprecated option