Sync to upstream/release/506

Analysis/include/Luau/FileResolver.h

@@ -51,13 +51,6 @@ struct FileResolver
     {
         return std::nullopt;
     }
-
-    // DEPRECATED APIS
-    // These are going to be removed with LuauNewRequireTrace2
-    virtual bool moduleExists(const ModuleName& name) const = 0;
-    virtual std::optional<ModuleName> fromAstFragment(AstExpr* expr) const = 0;
-    virtual ModuleName concat(const ModuleName& lhs, std::string_view rhs) const = 0;
-    virtual std::optional<ModuleName> getParentModuleName(const ModuleName& name) const = 0;
 };
 
 struct NullFileResolver : FileResolver
@@ -66,22 +59,6 @@ struct NullFileResolver : FileResolver
     {
         return std::nullopt;
     }
-    bool moduleExists(const ModuleName& name) const override
-    {
-        return false;
-    }
-    std::optional<ModuleName> fromAstFragment(AstExpr* expr) const override
-    {
-        return std::nullopt;
-    }
-    ModuleName concat(const ModuleName& lhs, std::string_view rhs) const override
-    {
-        return lhs;
-    }
-    std::optional<ModuleName> getParentModuleName(const ModuleName& name) const override
-    {
-        return std::nullopt;
-    }
 };
 
 } // namespace Luau

Analysis/include/Luau/Module.h

@@ -78,9 +78,15 @@ void unfreeze(TypeArena& arena);
 using SeenTypes = std::unordered_map<TypeId, TypeId>;
 using SeenTypePacks = std::unordered_map<TypePackId, TypePackId>;
 
-TypePackId clone(TypePackId tp, TypeArena& dest, SeenTypes& seenTypes, SeenTypePacks& seenTypePacks, bool* encounteredFreeType = nullptr);
+struct CloneState
-TypeId clone(TypeId tp, TypeArena& dest, SeenTypes& seenTypes, SeenTypePacks& seenTypePacks, bool* encounteredFreeType = nullptr);
+{
-TypeFun clone(const TypeFun& typeFun, TypeArena& dest, SeenTypes& seenTypes, SeenTypePacks& seenTypePacks, bool* encounteredFreeType = nullptr);
+    int recursionCount = 0;
+    bool encounteredFreeType = false;
+};
+
+TypePackId clone(TypePackId tp, TypeArena& dest, SeenTypes& seenTypes, SeenTypePacks& seenTypePacks, CloneState& cloneState);
+TypeId clone(TypeId tp, TypeArena& dest, SeenTypes& seenTypes, SeenTypePacks& seenTypePacks, CloneState& cloneState);
+TypeFun clone(const TypeFun& typeFun, TypeArena& dest, SeenTypes& seenTypes, SeenTypePacks& seenTypePacks, CloneState& cloneState);
 
 struct Module
 {

Analysis/include/Luau/ToDot.h

@@ -0,0 +1,31 @@
+// This file is part of the Luau programming language and is licensed under MIT License; see LICENSE.txt for details
+#pragma once
+
+#include "Luau/Common.h"
+
+#include <string>
+
+namespace Luau
+{
+struct TypeVar;
+using TypeId = const TypeVar*;
+
+struct TypePackVar;
+using TypePackId = const TypePackVar*;
+
+struct ToDotOptions
+{
+    bool showPointers = true;        // Show pointer value in the node label
+    bool duplicatePrimitives = true; // Display primitive types and 'any' as separate nodes
+};
+
+std::string toDot(TypeId ty, const ToDotOptions& opts);
+std::string toDot(TypePackId tp, const ToDotOptions& opts);
+
+std::string toDot(TypeId ty);
+std::string toDot(TypePackId tp);
+
+void dumpDot(TypeId ty);
+void dumpDot(TypePackId tp);
+
+} // namespace Luau

Analysis/include/Luau/TxnLog.h

@@ -25,15 +25,6 @@ struct TxnLog
     {
     }
 
-    explicit TxnLog(const std::vector<std::pair<TypeId, TypeId>>& ownedSeen)
-        : originalSeenSize(ownedSeen.size())
-        , ownedSeen(ownedSeen)
-        , sharedSeen(nullptr)
-    {
-        // This is deprecated!
-        LUAU_ASSERT(!FFlag::LuauShareTxnSeen);
-    }
-
     TxnLog(const TxnLog&) = delete;
     TxnLog& operator=(const TxnLog&) = delete;
 

Analysis/include/Luau/TypeInfer.h

@@ -297,7 +297,6 @@ private:
 
 private:
     Unifier mkUnifier(const Location& location);
-    Unifier mkUnifier(const std::vector<std::pair<TypeId, TypeId>>& seen, const Location& location);
 
     // These functions are only safe to call when we are in the process of typechecking a module.
 

Analysis/include/Luau/TypeVar.h

@@ -517,21 +517,6 @@ extern SingletonTypes singletonTypes;
 void persist(TypeId ty);
 void persist(TypePackId tp);
 
-struct ToDotOptions
-{
-    bool showPointers = true;        // Show pointer value in the node label
-    bool duplicatePrimitives = true; // Display primitive types and 'any' as separate nodes
-};
-
-std::string toDot(TypeId ty, const ToDotOptions& opts);
-std::string toDot(TypePackId tp, const ToDotOptions& opts);
-
-std::string toDot(TypeId ty);
-std::string toDot(TypePackId tp);
-
-void dumpDot(TypeId ty);
-void dumpDot(TypePackId tp);
-
 const TypeLevel* getLevel(TypeId ty);
 TypeLevel* getMutableLevel(TypeId ty);
 

Analysis/include/Luau/Unifier.h

@@ -19,12 +19,6 @@ enum Variance
     Invariant
 };
 
-struct UnifierCounters
-{
-    int recursionCount = 0;
-    int iterationCount = 0;
-};
-
 struct Unifier
 {
     TypeArena* const types;
@@ -37,20 +31,11 @@ struct Unifier
     Variance variance = Covariant;
     CountMismatch::Context ctx = CountMismatch::Arg;
 
-    UnifierCounters* counters;
-    UnifierCounters countersData;
-
-    std::shared_ptr<UnifierCounters> counters_DEPRECATED;
-
     UnifierSharedState& sharedState;
 
     Unifier(TypeArena* types, Mode mode, ScopePtr globalScope, const Location& location, Variance variance, UnifierSharedState& sharedState);
-    Unifier(TypeArena* types, Mode mode, ScopePtr globalScope, const std::vector<std::pair<TypeId, TypeId>>& ownedSeen, const Location& location,
-        Variance variance, UnifierSharedState& sharedState, const std::shared_ptr<UnifierCounters>& counters_DEPRECATED = nullptr,
-        UnifierCounters* counters = nullptr);
     Unifier(TypeArena* types, Mode mode, ScopePtr globalScope, std::vector<std::pair<TypeId, TypeId>>* sharedSeen, const Location& location,
-        Variance variance, UnifierSharedState& sharedState, const std::shared_ptr<UnifierCounters>& counters_DEPRECATED = nullptr,
+        Variance variance, UnifierSharedState& sharedState);
-        UnifierCounters* counters = nullptr);
 
     // Test whether the two type vars unify.  Never commits the result.
     ErrorVec canUnify(TypeId superTy, TypeId subTy);
@@ -92,9 +77,9 @@ private:
 public:
     // Report an "infinite type error" if the type "needle" already occurs within "haystack"
     void occursCheck(TypeId needle, TypeId haystack);
-    void occursCheck(std::unordered_set<TypeId>& seen_DEPRECATED, DenseHashSet<TypeId>& seen, TypeId needle, TypeId haystack);
+    void occursCheck(DenseHashSet<TypeId>& seen, TypeId needle, TypeId haystack);
     void occursCheck(TypePackId needle, TypePackId haystack);
-    void occursCheck(std::unordered_set<TypePackId>& seen_DEPRECATED, DenseHashSet<TypePackId>& seen, TypePackId needle, TypePackId haystack);
+    void occursCheck(DenseHashSet<TypePackId>& seen, TypePackId needle, TypePackId haystack);
 
     Unifier makeChildUnifier();
 
@@ -106,10 +91,6 @@ private:
 
     [[noreturn]] void ice(const std::string& message, const Location& location);
     [[noreturn]] void ice(const std::string& message);
-
-    // Remove with FFlagLuauCacheUnifyTableResults
-    DenseHashSet<TypeId> tempSeenTy_DEPRECATED{nullptr};
-    DenseHashSet<TypePackId> tempSeenTp_DEPRECATED{nullptr};
 };
 
 } // namespace Luau

Analysis/include/Luau/UnifierSharedState.h

@@ -24,6 +24,12 @@ struct TypeIdPairHash
     }
 };
 
+struct UnifierCounters
+{
+    int recursionCount = 0;
+    int iterationCount = 0;
+};
+
 struct UnifierSharedState
 {
     UnifierSharedState(InternalErrorReporter* iceHandler)
@@ -39,6 +45,8 @@ struct UnifierSharedState
 
     DenseHashSet<TypeId> tempSeenTy{nullptr};
     DenseHashSet<TypePackId> tempSeenTp{nullptr};
+
+    UnifierCounters counters;
 };
 
 } // namespace Luau

Analysis/include/Luau/VisitTypeVar.h

@@ -5,8 +5,6 @@
 #include "Luau/TypeVar.h"
 #include "Luau/TypePack.h"
 
-LUAU_FASTFLAG(LuauCacheUnifyTableResults)
-
 namespace Luau
 {
 
@@ -101,7 +99,7 @@ void visit(TypeId ty, F& f, Set& seen)
         // Some visitors want to see bound tables, that's why we visit the original type
         if (apply(ty, *ttv, seen, f))
         {
-            if (FFlag::LuauCacheUnifyTableResults && ttv->boundTo)
+            if (ttv->boundTo)
             {
                 visit(*ttv->boundTo, f, seen);
             }

Analysis/src/Autocomplete.cpp

@@ -12,9 +12,9 @@
 #include <unordered_set>
 #include <utility>
 
-LUAU_FASTFLAGVARIABLE(ElseElseIfCompletionImprovements, false);
 LUAU_FASTFLAG(LuauIfElseExpressionAnalysisSupport)
 LUAU_FASTFLAGVARIABLE(LuauAutocompleteAvoidMutation, false);
+LUAU_FASTFLAGVARIABLE(LuauAutocompletePreferToCallFunctions, false);
 
 static const std::unordered_set<std::string> kStatementStartingKeywords = {
     "while", "if", "local", "repeat", "function", "do", "for", "return", "break", "continue", "type", "export"};
@@ -203,8 +203,9 @@ static TypeCorrectKind checkTypeCorrectKind(const Module& module, TypeArena* typ
         {
             SeenTypes seenTypes;
             SeenTypePacks seenTypePacks;
-            expectedType = clone(expectedType, *typeArena, seenTypes, seenTypePacks, nullptr);
+            CloneState cloneState;
-            actualType = clone(actualType, *typeArena, seenTypes, seenTypePacks, nullptr);
+            expectedType = clone(expectedType, *typeArena, seenTypes, seenTypePacks, cloneState);
+            actualType = clone(actualType, *typeArena, seenTypes, seenTypePacks, cloneState);
 
             auto errors = unifier.canUnify(expectedType, actualType);
             return errors.empty();
@@ -229,28 +230,51 @@ static TypeCorrectKind checkTypeCorrectKind(const Module& module, TypeArena* typ
 
     TypeId expectedType = follow(*it);
 
-    if (canUnify(expectedType, ty))
+    if (FFlag::LuauAutocompletePreferToCallFunctions)
-        return TypeCorrectKind::Correct;
-
-    // We also want to suggest functions that return compatible result
-    const FunctionTypeVar* ftv = get<FunctionTypeVar>(ty);
-
-    if (!ftv)
-        return TypeCorrectKind::None;
-
-    auto [retHead, retTail] = flatten(ftv->retType);
-
-    if (!retHead.empty())
-        return canUnify(expectedType, retHead.front()) ? TypeCorrectKind::CorrectFunctionResult : TypeCorrectKind::None;
-
-    // We might only have a variadic tail pack, check if the element is compatible
-    if (retTail)
     {
-        if (const VariadicTypePack* vtp = get<VariadicTypePack>(follow(*retTail)))
+        // We also want to suggest functions that return compatible result
-            return canUnify(expectedType, vtp->ty) ? TypeCorrectKind::CorrectFunctionResult : TypeCorrectKind::None;
+        if (const FunctionTypeVar* ftv = get<FunctionTypeVar>(ty))
-    }
+        {
+            auto [retHead, retTail] = flatten(ftv->retType);
 
-    return TypeCorrectKind::None;
+            if (!retHead.empty() && canUnify(expectedType, retHead.front()))
+                return TypeCorrectKind::CorrectFunctionResult;
+
+            // We might only have a variadic tail pack, check if the element is compatible
+            if (retTail)
+            {
+                if (const VariadicTypePack* vtp = get<VariadicTypePack>(follow(*retTail)); vtp && canUnify(expectedType, vtp->ty))
+                    return TypeCorrectKind::CorrectFunctionResult;
+            }
+        }
+
+        return canUnify(expectedType, ty) ? TypeCorrectKind::Correct : TypeCorrectKind::None;
+    }
+    else
+    {
+        if (canUnify(expectedType, ty))
+            return TypeCorrectKind::Correct;
+
+        // We also want to suggest functions that return compatible result
+        const FunctionTypeVar* ftv = get<FunctionTypeVar>(ty);
+
+        if (!ftv)
+            return TypeCorrectKind::None;
+
+        auto [retHead, retTail] = flatten(ftv->retType);
+
+        if (!retHead.empty())
+            return canUnify(expectedType, retHead.front()) ? TypeCorrectKind::CorrectFunctionResult : TypeCorrectKind::None;
+
+        // We might only have a variadic tail pack, check if the element is compatible
+        if (retTail)
+        {
+            if (const VariadicTypePack* vtp = get<VariadicTypePack>(follow(*retTail)))
+                return canUnify(expectedType, vtp->ty) ? TypeCorrectKind::CorrectFunctionResult : TypeCorrectKind::None;
+        }
+
+        return TypeCorrectKind::None;
+    }
 }
 
 enum class PropIndexType
@@ -1413,7 +1437,7 @@ static AutocompleteResult autocomplete(const SourceModule& sourceModule, const M
     else if (AstStatWhile* statWhile = extractStat<AstStatWhile>(finder.ancestry); statWhile && !statWhile->hasDo)
         return {{{"do", AutocompleteEntry{AutocompleteEntryKind::Keyword}}}, finder.ancestry};
 
-    else if (AstStatIf* statIf = node->as<AstStatIf>(); FFlag::ElseElseIfCompletionImprovements && statIf && !statIf->hasElse)
+    else if (AstStatIf* statIf = node->as<AstStatIf>(); statIf && !statIf->hasElse)
     {
         return {{{"else", AutocompleteEntry{AutocompleteEntryKind::Keyword}}, {"elseif", AutocompleteEntry{AutocompleteEntryKind::Keyword}}},
             finder.ancestry};

Analysis/src/BuiltinDefinitions.cpp

@@ -8,8 +8,6 @@
 
 #include <algorithm>
 
-LUAU_FASTFLAG(LuauNewRequireTrace2)
-
 /** FIXME: Many of these type definitions are not quite completely accurate.
  *
  * Some of them require richer generics than we have.  For instance, we do not yet have a way to talk
@@ -473,9 +471,7 @@ static std::optional<ExprResult<TypePackId>> magicFunctionRequire(
     if (!checkRequirePath(typechecker, expr.args.data[0]))
         return std::nullopt;
 
-    const AstExpr* require = FFlag::LuauNewRequireTrace2 ? &expr : expr.args.data[0];
+    if (auto moduleInfo = typechecker.resolver->resolveModuleInfo(typechecker.currentModuleName, expr))
-
-    if (auto moduleInfo = typechecker.resolver->resolveModuleInfo(typechecker.currentModuleName, *require))
         return ExprResult<TypePackId>{arena.addTypePack({typechecker.checkRequire(scope, *moduleInfo, expr.location)})};
 
     return std::nullopt;

Analysis/src/Error.cpp

@@ -7,57 +7,14 @@
 
 #include <stdexcept>
 
-LUAU_FASTFLAG(LuauTypeAliasPacks)
-
-static std::string wrongNumberOfArgsString_DEPRECATED(size_t expectedCount, size_t actualCount, bool isTypeArgs = false)
-{
-    std::string s = "expects " + std::to_string(expectedCount) + " ";
-
-    if (isTypeArgs)
-        s += "type ";
-
-    s += "argument";
-    if (expectedCount != 1)
-        s += "s";
-
-    s += ", but ";
-
-    if (actualCount == 0)
-    {
-        s += "none";
-    }
-    else
-    {
-        if (actualCount < expectedCount)
-            s += "only ";
-
-        s += std::to_string(actualCount);
-    }
-
-    s += (actualCount == 1) ? " is" : " are";
-
-    s += " specified";
-
-    return s;
-}
-
 static std::string wrongNumberOfArgsString(size_t expectedCount, size_t actualCount, const char* argPrefix = nullptr, bool isVariadic = false)
 {
-    std::string s;
+    std::string s = "expects ";
 
-    if (FFlag::LuauTypeAliasPacks)
+    if (isVariadic)
-    {
+        s += "at least ";
-        s = "expects ";
 
-        if (isVariadic)
+    s += std::to_string(expectedCount) + " ";
-            s += "at least ";
-
-        s += std::to_string(expectedCount) + " ";
-    }
-    else
-    {
-        s = "expects " + std::to_string(expectedCount) + " ";
-    }
 
     if (argPrefix)
         s += std::string(argPrefix) + " ";
@@ -188,10 +145,7 @@ struct ErrorConverter
             return "Function only returns " + std::to_string(e.expected) + " value" + expectedS + ". " + std::to_string(e.actual) +
                    " are required here";
         case CountMismatch::Arg:
-            if (FFlag::LuauTypeAliasPacks)
+            return "Argument count mismatch. Function " + wrongNumberOfArgsString(e.expected, e.actual);
-                return "Argument count mismatch. Function " + wrongNumberOfArgsString(e.expected, e.actual);
-            else
-                return "Argument count mismatch. Function " + wrongNumberOfArgsString_DEPRECATED(e.expected, e.actual);
         }
 
         LUAU_ASSERT(!"Unknown context");
@@ -232,7 +186,7 @@ struct ErrorConverter
     std::string operator()(const Luau::IncorrectGenericParameterCount& e) const
     {
         std::string name = e.name;
-        if (!e.typeFun.typeParams.empty() || (FFlag::LuauTypeAliasPacks && !e.typeFun.typePackParams.empty()))
+        if (!e.typeFun.typeParams.empty() || !e.typeFun.typePackParams.empty())
         {
             name += "<";
             bool first = true;
@@ -246,36 +200,25 @@ struct ErrorConverter
                 name += toString(t);
             }
 
-            if (FFlag::LuauTypeAliasPacks)
+            for (TypePackId t : e.typeFun.typePackParams)
             {
-                for (TypePackId t : e.typeFun.typePackParams)
+                if (first)
-                {
+                    first = false;
-                    if (first)
+                else
-                        first = false;
+                    name += ", ";
-                    else
-                        name += ", ";
 
-                    name += toString(t);
+                name += toString(t);
-                }
             }
 
             name += ">";
         }
 
-        if (FFlag::LuauTypeAliasPacks)
+        if (e.typeFun.typeParams.size() != e.actualParameters)
-        {
+            return "Generic type '" + name + "' " +
-            if (e.typeFun.typeParams.size() != e.actualParameters)
+                   wrongNumberOfArgsString(e.typeFun.typeParams.size(), e.actualParameters, "type", !e.typeFun.typePackParams.empty());
-                return "Generic type '" + name + "' " +
-                       wrongNumberOfArgsString(e.typeFun.typeParams.size(), e.actualParameters, "type", !e.typeFun.typePackParams.empty());
 
-            return "Generic type '" + name + "' " +
+        return "Generic type '" + name + "' " +
-                   wrongNumberOfArgsString(e.typeFun.typePackParams.size(), e.actualPackParameters, "type pack", /*isVariadic*/ false);
+               wrongNumberOfArgsString(e.typeFun.typePackParams.size(), e.actualPackParameters, "type pack", /*isVariadic*/ false);
-        }
-        else
-        {
-            return "Generic type '" + name + "' " +
-                   wrongNumberOfArgsString_DEPRECATED(e.typeFun.typeParams.size(), e.actualParameters, /*isTypeArgs*/ true);
-        }
     }
 
     std::string operator()(const Luau::SyntaxError& e) const
@@ -591,11 +534,8 @@ bool IncorrectGenericParameterCount::operator==(const IncorrectGenericParameterC
     if (typeFun.typeParams.size() != rhs.typeFun.typeParams.size())
         return false;
 
-    if (FFlag::LuauTypeAliasPacks)
+    if (typeFun.typePackParams.size() != rhs.typeFun.typePackParams.size())
-    {
+        return false;
-        if (typeFun.typePackParams.size() != rhs.typeFun.typePackParams.size())
-            return false;
-    }
 
     for (size_t i = 0; i < typeFun.typeParams.size(); ++i)
     {
@@ -603,13 +543,10 @@ bool IncorrectGenericParameterCount::operator==(const IncorrectGenericParameterC
             return false;
     }
 
-    if (FFlag::LuauTypeAliasPacks)
+    for (size_t i = 0; i < typeFun.typePackParams.size(); ++i)
     {
-        for (size_t i = 0; i < typeFun.typePackParams.size(); ++i)
+        if (typeFun.typePackParams[i] != rhs.typeFun.typePackParams[i])
-        {
+            return false;
-            if (typeFun.typePackParams[i] != rhs.typeFun.typePackParams[i])
-                return false;
-        }
     }
 
     return true;
@@ -733,14 +670,14 @@ bool containsParseErrorName(const TypeError& error)
 }
 
 template<typename T>
-void copyError(T& e, TypeArena& destArena, SeenTypes& seenTypes, SeenTypePacks& seenTypePacks)
+void copyError(T& e, TypeArena& destArena, SeenTypes& seenTypes, SeenTypePacks& seenTypePacks, CloneState cloneState)
 {
     auto clone = [&](auto&& ty) {
-        return ::Luau::clone(ty, destArena, seenTypes, seenTypePacks);
+        return ::Luau::clone(ty, destArena, seenTypes, seenTypePacks, cloneState);
     };
 
     auto visitErrorData = [&](auto&& e) {
-        copyError(e, destArena, seenTypes, seenTypePacks);
+        copyError(e, destArena, seenTypes, seenTypePacks, cloneState);
     };
 
     if constexpr (false)
@@ -864,9 +801,10 @@ void copyErrors(ErrorVec& errors, TypeArena& destArena)
 {
     SeenTypes seenTypes;
     SeenTypePacks seenTypePacks;
+    CloneState cloneState;
 
     auto visitErrorData = [&](auto&& e) {
-        copyError(e, destArena, seenTypes, seenTypePacks);
+        copyError(e, destArena, seenTypes, seenTypePacks, cloneState);
     };
 
     LUAU_ASSERT(!destArena.typeVars.isFrozen());

Analysis/src/Frontend.cpp

@@ -18,10 +18,7 @@
 LUAU_FASTFLAG(LuauInferInNoCheckMode)
 LUAU_FASTFLAGVARIABLE(LuauTypeCheckTwice, false)
 LUAU_FASTFLAGVARIABLE(LuauKnowsTheDataModel3, false)
-LUAU_FASTFLAGVARIABLE(LuauResolveModuleNameWithoutACurrentModule, false)
-LUAU_FASTFLAG(LuauTraceRequireLookupChild)
 LUAU_FASTFLAGVARIABLE(LuauPersistDefinitionFileTypes, false)
-LUAU_FASTFLAG(LuauNewRequireTrace2)
 
 namespace Luau
 {
@@ -96,10 +93,11 @@ LoadDefinitionFileResult loadDefinitionFile(TypeChecker& typeChecker, ScopePtr t
 
     SeenTypes seenTypes;
     SeenTypePacks seenTypePacks;
+    CloneState cloneState;
 
     for (const auto& [name, ty] : checkedModule->declaredGlobals)
     {
-        TypeId globalTy = clone(ty, typeChecker.globalTypes, seenTypes, seenTypePacks);
+        TypeId globalTy = clone(ty, typeChecker.globalTypes, seenTypes, seenTypePacks, cloneState);
         std::string documentationSymbol = packageName + "/global/" + name;
         generateDocumentationSymbols(globalTy, documentationSymbol);
         targetScope->bindings[typeChecker.globalNames.names->getOrAdd(name.c_str())] = {globalTy, Location(), false, {}, documentationSymbol};
@@ -110,7 +108,7 @@ LoadDefinitionFileResult loadDefinitionFile(TypeChecker& typeChecker, ScopePtr t
 
     for (const auto& [name, ty] : checkedModule->getModuleScope()->exportedTypeBindings)
     {
-        TypeFun globalTy = clone(ty, typeChecker.globalTypes, seenTypes, seenTypePacks);
+        TypeFun globalTy = clone(ty, typeChecker.globalTypes, seenTypes, seenTypePacks, cloneState);
         std::string documentationSymbol = packageName + "/globaltype/" + name;
         generateDocumentationSymbols(globalTy.type, documentationSymbol);
         targetScope->exportedTypeBindings[name] = globalTy;
@@ -427,15 +425,16 @@ CheckResult Frontend::check(const ModuleName& name)
 
             SeenTypes seenTypes;
             SeenTypePacks seenTypePacks;
+            CloneState cloneState;
 
             for (const auto& [expr, strictTy] : strictModule->astTypes)
-                module->astTypes[expr] = clone(strictTy, module->interfaceTypes, seenTypes, seenTypePacks);
+                module->astTypes[expr] = clone(strictTy, module->interfaceTypes, seenTypes, seenTypePacks, cloneState);
 
             for (const auto& [expr, strictTy] : strictModule->astOriginalCallTypes)
-                module->astOriginalCallTypes[expr] = clone(strictTy, module->interfaceTypes, seenTypes, seenTypePacks);
+                module->astOriginalCallTypes[expr] = clone(strictTy, module->interfaceTypes, seenTypes, seenTypePacks, cloneState);
 
             for (const auto& [expr, strictTy] : strictModule->astExpectedTypes)
-                module->astExpectedTypes[expr] = clone(strictTy, module->interfaceTypes, seenTypes, seenTypePacks);
+                module->astExpectedTypes[expr] = clone(strictTy, module->interfaceTypes, seenTypes, seenTypePacks, cloneState);
         }
 
         stats.timeCheck += getTimestamp() - timestamp;
@@ -885,16 +884,13 @@ std::optional<ModuleInfo> FrontendModuleResolver::resolveModuleInfo(const Module
         // If we can't find the current module name, that's because we bypassed the frontend's initializer
         // and called typeChecker.check directly. (This is done by autocompleteSource, for example).
         // In that case, requires will always fail.
-        if (FFlag::LuauResolveModuleNameWithoutACurrentModule)
+        return std::nullopt;
-            return std::nullopt;
-        else
-            throw std::runtime_error("Frontend::resolveModuleName: Unknown currentModuleName '" + currentModuleName + "'");
     }
 
     const auto& exprs = it->second.exprs;
 
     const ModuleInfo* info = exprs.find(&pathExpr);
-    if (!info || (!FFlag::LuauNewRequireTrace2 && info->name.empty()))
+    if (!info)
         return std::nullopt;
 
     return *info;
@@ -911,10 +907,7 @@ const ModulePtr FrontendModuleResolver::getModule(const ModuleName& moduleName)
 
 bool FrontendModuleResolver::moduleExists(const ModuleName& moduleName) const
 {
-    if (FFlag::LuauNewRequireTrace2)
+    return frontend->sourceNodes.count(moduleName) != 0;
-        return frontend->sourceNodes.count(moduleName) != 0;
-    else
-        return frontend->fileResolver->moduleExists(moduleName);
 }
 
 std::string FrontendModuleResolver::getHumanReadableModuleName(const ModuleName& moduleName) const

Analysis/src/IostreamHelpers.cpp

@@ -2,8 +2,6 @@
 #include "Luau/IostreamHelpers.h"
 #include "Luau/ToString.h"
 
-LUAU_FASTFLAG(LuauTypeAliasPacks)
-
 namespace Luau
 {
 
@@ -94,7 +92,7 @@ std::ostream& operator<<(std::ostream& stream, const IncorrectGenericParameterCo
 {
     stream << "IncorrectGenericParameterCount { name = " << error.name;
 
-    if (!error.typeFun.typeParams.empty() || (FFlag::LuauTypeAliasPacks && !error.typeFun.typePackParams.empty()))
+    if (!error.typeFun.typeParams.empty() || !error.typeFun.typePackParams.empty())
     {
         stream << "<";
         bool first = true;
@@ -108,17 +106,14 @@ std::ostream& operator<<(std::ostream& stream, const IncorrectGenericParameterCo
             stream << toString(t);
         }
 
-        if (FFlag::LuauTypeAliasPacks)
+        for (TypePackId t : error.typeFun.typePackParams)
         {
-            for (TypePackId t : error.typeFun.typePackParams)
+            if (first)
-            {
+                first = false;
-                if (first)
+            else
-                    first = false;
+                stream << ", ";
-                else
-                    stream << ", ";
 
-                stream << toString(t);
+            stream << toString(t);
-            }
         }
 
         stream << ">";

Analysis/src/JsonEncoder.cpp

@@ -5,8 +5,6 @@
 #include "Luau/StringUtils.h"
 #include "Luau/Common.h"
 
-LUAU_FASTFLAG(LuauTypeAliasPacks)
-
 namespace Luau
 {
 
@@ -615,12 +613,7 @@ struct AstJsonEncoder : public AstVisitor
         writeNode(node, "AstStatTypeAlias", [&]() {
             PROP(name);
             PROP(generics);
-
+            PROP(genericPacks);
-            if (FFlag::LuauTypeAliasPacks)
-            {
-                PROP(genericPacks);
-            }
-
             PROP(type);
             PROP(exported);
         });

Analysis/src/Module.cpp

@@ -1,20 +1,20 @@
 // This file is part of the Luau programming language and is licensed under MIT License; see LICENSE.txt for details
 #include "Luau/Module.h"
 
+#include "Luau/Common.h"
+#include "Luau/RecursionCounter.h"
 #include "Luau/Scope.h"
 #include "Luau/TypeInfer.h"
 #include "Luau/TypePack.h"
 #include "Luau/TypeVar.h"
 #include "Luau/VisitTypeVar.h"
-#include "Luau/Common.h"
 
 #include <algorithm>
 
 LUAU_FASTFLAGVARIABLE(DebugLuauFreezeArena, false)
 LUAU_FASTFLAGVARIABLE(DebugLuauTrackOwningArena, false)
 LUAU_FASTFLAG(LuauCaptureBrokenCommentSpans)
-LUAU_FASTFLAG(LuauTypeAliasPacks)
+LUAU_FASTINTVARIABLE(LuauTypeCloneRecursionLimit, 0)
-LUAU_FASTFLAGVARIABLE(LuauCloneBoundTables, false)
 
 namespace Luau
 {
@@ -120,12 +120,6 @@ TypePackId TypeArena::addTypePack(TypePackVar tp)
     return allocated;
 }
 
-using SeenTypes = std::unordered_map<TypeId, TypeId>;
-using SeenTypePacks = std::unordered_map<TypePackId, TypePackId>;
-
-TypePackId clone(TypePackId tp, TypeArena& dest, SeenTypes& seenTypes, SeenTypePacks& seenTypePacks, bool* encounteredFreeType);
-TypeId clone(TypeId tp, TypeArena& dest, SeenTypes& seenTypes, SeenTypePacks& seenTypePacks, bool* encounteredFreeType);
-
 namespace
 {
 
@@ -138,11 +132,12 @@ struct TypePackCloner;
 
 struct TypeCloner
 {
-    TypeCloner(TypeArena& dest, TypeId typeId, SeenTypes& seenTypes, SeenTypePacks& seenTypePacks)
+    TypeCloner(TypeArena& dest, TypeId typeId, SeenTypes& seenTypes, SeenTypePacks& seenTypePacks, CloneState& cloneState)
         : dest(dest)
         , typeId(typeId)
         , seenTypes(seenTypes)
         , seenTypePacks(seenTypePacks)
+        , cloneState(cloneState)
     {
     }
 
@@ -150,8 +145,7 @@ struct TypeCloner
     TypeId typeId;
     SeenTypes& seenTypes;
     SeenTypePacks& seenTypePacks;
-
+    CloneState& cloneState;
-    bool* encounteredFreeType = nullptr;
 
     template<typename T>
     void defaultClone(const T& t);
@@ -178,13 +172,14 @@ struct TypePackCloner
     TypePackId typePackId;
     SeenTypes& seenTypes;
     SeenTypePacks& seenTypePacks;
-    bool* encounteredFreeType = nullptr;
+    CloneState& cloneState;
 
-    TypePackCloner(TypeArena& dest, TypePackId typePackId, SeenTypes& seenTypes, SeenTypePacks& seenTypePacks)
+    TypePackCloner(TypeArena& dest, TypePackId typePackId, SeenTypes& seenTypes, SeenTypePacks& seenTypePacks, CloneState& cloneState)
         : dest(dest)
         , typePackId(typePackId)
         , seenTypes(seenTypes)
         , seenTypePacks(seenTypePacks)
+        , cloneState(cloneState)
     {
     }
 
@@ -197,8 +192,7 @@ struct TypePackCloner
 
     void operator()(const Unifiable::Free& t)
     {
-        if (encounteredFreeType)
+        cloneState.encounteredFreeType = true;
-            *encounteredFreeType = true;
 
         TypePackId err = singletonTypes.errorRecoveryTypePack(singletonTypes.anyTypePack);
         TypePackId cloned = dest.addTypePack(*err);
@@ -218,13 +212,13 @@ struct TypePackCloner
     // We just need to be sure that we rewrite pointers both to the binder and the bindee to the same pointer.
     void operator()(const Unifiable::Bound<TypePackId>& t)
     {
-        TypePackId cloned = clone(t.boundTo, dest, seenTypes, seenTypePacks, encounteredFreeType);
+        TypePackId cloned = clone(t.boundTo, dest, seenTypes, seenTypePacks, cloneState);
         seenTypePacks[typePackId] = cloned;
     }
 
     void operator()(const VariadicTypePack& t)
     {
-        TypePackId cloned = dest.addTypePack(TypePackVar{VariadicTypePack{clone(t.ty, dest, seenTypes, seenTypePacks, encounteredFreeType)}});
+        TypePackId cloned = dest.addTypePack(TypePackVar{VariadicTypePack{clone(t.ty, dest, seenTypes, seenTypePacks, cloneState)}});
         seenTypePacks[typePackId] = cloned;
     }
 
@@ -236,10 +230,10 @@ struct TypePackCloner
         seenTypePacks[typePackId] = cloned;
 
         for (TypeId ty : t.head)
-            destTp->head.push_back(clone(ty, dest, seenTypes, seenTypePacks, encounteredFreeType));
+            destTp->head.push_back(clone(ty, dest, seenTypes, seenTypePacks, cloneState));
 
         if (t.tail)
-            destTp->tail = clone(*t.tail, dest, seenTypes, seenTypePacks, encounteredFreeType);
+            destTp->tail = clone(*t.tail, dest, seenTypes, seenTypePacks, cloneState);
     }
 };
 
@@ -252,8 +246,7 @@ void TypeCloner::defaultClone(const T& t)
 
 void TypeCloner::operator()(const Unifiable::Free& t)
 {
-    if (encounteredFreeType)
+    cloneState.encounteredFreeType = true;
-        *encounteredFreeType = true;
     TypeId err = singletonTypes.errorRecoveryType(singletonTypes.anyType);
     TypeId cloned = dest.addType(*err);
     seenTypes[typeId] = cloned;
@@ -266,7 +259,7 @@ void TypeCloner::operator()(const Unifiable::Generic& t)
 
 void TypeCloner::operator()(const Unifiable::Bound<TypeId>& t)
 {
-    TypeId boundTo = clone(t.boundTo, dest, seenTypes, seenTypePacks, encounteredFreeType);
+    TypeId boundTo = clone(t.boundTo, dest, seenTypes, seenTypePacks, cloneState);
     seenTypes[typeId] = boundTo;
 }
 
@@ -294,23 +287,23 @@ void TypeCloner::operator()(const FunctionTypeVar& t)
     seenTypes[typeId] = result;
 
     for (TypeId generic : t.generics)
-        ftv->generics.push_back(clone(generic, dest, seenTypes, seenTypePacks, encounteredFreeType));
+        ftv->generics.push_back(clone(generic, dest, seenTypes, seenTypePacks, cloneState));
 
     for (TypePackId genericPack : t.genericPacks)
-        ftv->genericPacks.push_back(clone(genericPack, dest, seenTypes, seenTypePacks, encounteredFreeType));
+        ftv->genericPacks.push_back(clone(genericPack, dest, seenTypes, seenTypePacks, cloneState));
 
     ftv->tags = t.tags;
-    ftv->argTypes = clone(t.argTypes, dest, seenTypes, seenTypePacks, encounteredFreeType);
+    ftv->argTypes = clone(t.argTypes, dest, seenTypes, seenTypePacks, cloneState);
     ftv->argNames = t.argNames;
-    ftv->retType = clone(t.retType, dest, seenTypes, seenTypePacks, encounteredFreeType);
+    ftv->retType = clone(t.retType, dest, seenTypes, seenTypePacks, cloneState);
 }
 
 void TypeCloner::operator()(const TableTypeVar& t)
 {
     // If table is now bound to another one, we ignore the content of the original
-    if (FFlag::LuauCloneBoundTables && t.boundTo)
+    if (t.boundTo)
     {
-        TypeId boundTo = clone(*t.boundTo, dest, seenTypes, seenTypePacks, encounteredFreeType);
+        TypeId boundTo = clone(*t.boundTo, dest, seenTypes, seenTypePacks, cloneState);
         seenTypes[typeId] = boundTo;
         return;
     }
@@ -326,34 +319,21 @@ void TypeCloner::operator()(const TableTypeVar& t)
     ttv->level = TypeLevel{0, 0};
 
     for (const auto& [name, prop] : t.props)
-        ttv->props[name] = {clone(prop.type, dest, seenTypes, seenTypePacks, encounteredFreeType), prop.deprecated, {}, prop.location, prop.tags};
+        ttv->props[name] = {clone(prop.type, dest, seenTypes, seenTypePacks, cloneState), prop.deprecated, {}, prop.location, prop.tags};
 
     if (t.indexer)
-        ttv->indexer = TableIndexer{clone(t.indexer->indexType, dest, seenTypes, seenTypePacks, encounteredFreeType),
+        ttv->indexer = TableIndexer{clone(t.indexer->indexType, dest, seenTypes, seenTypePacks, cloneState),
-            clone(t.indexer->indexResultType, dest, seenTypes, seenTypePacks, encounteredFreeType)};
+            clone(t.indexer->indexResultType, dest, seenTypes, seenTypePacks, cloneState)};
-
-    if (!FFlag::LuauCloneBoundTables)
-    {
-        if (t.boundTo)
-            ttv->boundTo = clone(*t.boundTo, dest, seenTypes, seenTypePacks, encounteredFreeType);
-    }
 
     for (TypeId& arg : ttv->instantiatedTypeParams)
-        arg = clone(arg, dest, seenTypes, seenTypePacks, encounteredFreeType);
+        arg = clone(arg, dest, seenTypes, seenTypePacks, cloneState);
 
-    if (FFlag::LuauTypeAliasPacks)
+    for (TypePackId& arg : ttv->instantiatedTypePackParams)
-    {
+        arg = clone(arg, dest, seenTypes, seenTypePacks, cloneState);
-        for (TypePackId& arg : ttv->instantiatedTypePackParams)
-            arg = clone(arg, dest, seenTypes, seenTypePacks, encounteredFreeType);
-    }
 
     if (ttv->state == TableState::Free)
     {
-        if (FFlag::LuauCloneBoundTables || !t.boundTo)
+        cloneState.encounteredFreeType = true;
-        {
-            if (encounteredFreeType)
-                *encounteredFreeType = true;
-        }
 
         ttv->state = TableState::Sealed;
     }
@@ -369,8 +349,8 @@ void TypeCloner::operator()(const MetatableTypeVar& t)
     MetatableTypeVar* mtv = getMutable<MetatableTypeVar>(result);
     seenTypes[typeId] = result;
 
-    mtv->table = clone(t.table, dest, seenTypes, seenTypePacks, encounteredFreeType);
+    mtv->table = clone(t.table, dest, seenTypes, seenTypePacks, cloneState);
-    mtv->metatable = clone(t.metatable, dest, seenTypes, seenTypePacks, encounteredFreeType);
+    mtv->metatable = clone(t.metatable, dest, seenTypes, seenTypePacks, cloneState);
 }
 
 void TypeCloner::operator()(const ClassTypeVar& t)
@@ -381,13 +361,13 @@ void TypeCloner::operator()(const ClassTypeVar& t)
     seenTypes[typeId] = result;
 
     for (const auto& [name, prop] : t.props)
-        ctv->props[name] = {clone(prop.type, dest, seenTypes, seenTypePacks, encounteredFreeType), prop.deprecated, {}, prop.location, prop.tags};
+        ctv->props[name] = {clone(prop.type, dest, seenTypes, seenTypePacks, cloneState), prop.deprecated, {}, prop.location, prop.tags};
 
     if (t.parent)
-        ctv->parent = clone(*t.parent, dest, seenTypes, seenTypePacks, encounteredFreeType);
+        ctv->parent = clone(*t.parent, dest, seenTypes, seenTypePacks, cloneState);
 
     if (t.metatable)
-        ctv->metatable = clone(*t.metatable, dest, seenTypes, seenTypePacks, encounteredFreeType);
+        ctv->metatable = clone(*t.metatable, dest, seenTypes, seenTypePacks, cloneState);
 }
 
 void TypeCloner::operator()(const AnyTypeVar& t)
@@ -404,7 +384,7 @@ void TypeCloner::operator()(const UnionTypeVar& t)
     LUAU_ASSERT(option != nullptr);
 
     for (TypeId ty : t.options)
-        option->options.push_back(clone(ty, dest, seenTypes, seenTypePacks, encounteredFreeType));
+        option->options.push_back(clone(ty, dest, seenTypes, seenTypePacks, cloneState));
 }
 
 void TypeCloner::operator()(const IntersectionTypeVar& t)
@@ -416,7 +396,7 @@ void TypeCloner::operator()(const IntersectionTypeVar& t)
     LUAU_ASSERT(option != nullptr);
 
     for (TypeId ty : t.parts)
-        option->parts.push_back(clone(ty, dest, seenTypes, seenTypePacks, encounteredFreeType));
+        option->parts.push_back(clone(ty, dest, seenTypes, seenTypePacks, cloneState));
 }
 
 void TypeCloner::operator()(const LazyTypeVar& t)
@@ -426,17 +406,18 @@ void TypeCloner::operator()(const LazyTypeVar& t)
 
 } // anonymous namespace
 
-TypePackId clone(TypePackId tp, TypeArena& dest, SeenTypes& seenTypes, SeenTypePacks& seenTypePacks, bool* encounteredFreeType)
+TypePackId clone(TypePackId tp, TypeArena& dest, SeenTypes& seenTypes, SeenTypePacks& seenTypePacks, CloneState& cloneState)
 {
     if (tp->persistent)
         return tp;
 
+    RecursionLimiter _ra(&cloneState.recursionCount, FInt::LuauTypeCloneRecursionLimit);
+
     TypePackId& res = seenTypePacks[tp];
 
     if (res == nullptr)
     {
-        TypePackCloner cloner{dest, tp, seenTypes, seenTypePacks};
+        TypePackCloner cloner{dest, tp, seenTypes, seenTypePacks, cloneState};
-        cloner.encounteredFreeType = encounteredFreeType;
         Luau::visit(cloner, tp->ty); // Mutates the storage that 'res' points into.
     }
 
@@ -446,17 +427,18 @@ TypePackId clone(TypePackId tp, TypeArena& dest, SeenTypes& seenTypes, SeenTypeP
     return res;
 }
 
-TypeId clone(TypeId typeId, TypeArena& dest, SeenTypes& seenTypes, SeenTypePacks& seenTypePacks, bool* encounteredFreeType)
+TypeId clone(TypeId typeId, TypeArena& dest, SeenTypes& seenTypes, SeenTypePacks& seenTypePacks, CloneState& cloneState)
 {
     if (typeId->persistent)
         return typeId;
 
+    RecursionLimiter _ra(&cloneState.recursionCount, FInt::LuauTypeCloneRecursionLimit);
+
     TypeId& res = seenTypes[typeId];
 
     if (res == nullptr)
     {
-        TypeCloner cloner{dest, typeId, seenTypes, seenTypePacks};
+        TypeCloner cloner{dest, typeId, seenTypes, seenTypePacks, cloneState};
-        cloner.encounteredFreeType = encounteredFreeType;
         Luau::visit(cloner, typeId->ty); // Mutates the storage that 'res' points into.
         asMutable(res)->documentationSymbol = typeId->documentationSymbol;
     }
@@ -467,19 +449,16 @@ TypeId clone(TypeId typeId, TypeArena& dest, SeenTypes& seenTypes, SeenTypePacks
     return res;
 }
 
-TypeFun clone(const TypeFun& typeFun, TypeArena& dest, SeenTypes& seenTypes, SeenTypePacks& seenTypePacks, bool* encounteredFreeType)
+TypeFun clone(const TypeFun& typeFun, TypeArena& dest, SeenTypes& seenTypes, SeenTypePacks& seenTypePacks, CloneState& cloneState)
 {
     TypeFun result;
     for (TypeId ty : typeFun.typeParams)
-        result.typeParams.push_back(clone(ty, dest, seenTypes, seenTypePacks, encounteredFreeType));
+        result.typeParams.push_back(clone(ty, dest, seenTypes, seenTypePacks, cloneState));
 
-    if (FFlag::LuauTypeAliasPacks)
+    for (TypePackId tp : typeFun.typePackParams)
-    {
+        result.typePackParams.push_back(clone(tp, dest, seenTypes, seenTypePacks, cloneState));
-        for (TypePackId tp : typeFun.typePackParams)
-            result.typePackParams.push_back(clone(tp, dest, seenTypes, seenTypePacks, encounteredFreeType));
-    }
 
-    result.type = clone(typeFun.type, dest, seenTypes, seenTypePacks, encounteredFreeType);
+    result.type = clone(typeFun.type, dest, seenTypes, seenTypePacks, cloneState);
 
     return result;
 }
@@ -519,19 +498,18 @@ bool Module::clonePublicInterface()
     LUAU_ASSERT(interfaceTypes.typeVars.empty());
     LUAU_ASSERT(interfaceTypes.typePacks.empty());
 
-    bool encounteredFreeType = false;
-
-    SeenTypePacks seenTypePacks;
     SeenTypes seenTypes;
+    SeenTypePacks seenTypePacks;
+    CloneState cloneState;
 
     ScopePtr moduleScope = getModuleScope();
 
-    moduleScope->returnType = clone(moduleScope->returnType, interfaceTypes, seenTypes, seenTypePacks, &encounteredFreeType);
+    moduleScope->returnType = clone(moduleScope->returnType, interfaceTypes, seenTypes, seenTypePacks, cloneState);
     if (moduleScope->varargPack)
-        moduleScope->varargPack = clone(*moduleScope->varargPack, interfaceTypes, seenTypes, seenTypePacks, &encounteredFreeType);
+        moduleScope->varargPack = clone(*moduleScope->varargPack, interfaceTypes, seenTypes, seenTypePacks, cloneState);
 
     for (auto& pair : moduleScope->exportedTypeBindings)
-        pair.second = clone(pair.second, interfaceTypes, seenTypes, seenTypePacks, &encounteredFreeType);
+        pair.second = clone(pair.second, interfaceTypes, seenTypes, seenTypePacks, cloneState);
 
     for (TypeId ty : moduleScope->returnType)
         if (get<GenericTypeVar>(follow(ty)))
@@ -540,7 +518,7 @@ bool Module::clonePublicInterface()
     freeze(internalTypes);
     freeze(interfaceTypes);
 
-    return encounteredFreeType;
+    return cloneState.encounteredFreeType;
 }
 
 } // namespace Luau

Analysis/src/Quantify.cpp

@@ -4,6 +4,8 @@
 
 #include "Luau/VisitTypeVar.h"
 
+LUAU_FASTFLAGVARIABLE(LuauQuantifyVisitOnce, false)
+
 namespace Luau
 {
 
@@ -79,7 +81,16 @@ struct Quantifier
 void quantify(ModulePtr module, TypeId ty, TypeLevel level)
 {
     Quantifier q{std::move(module), level};
-    visitTypeVar(ty, q);
+
+    if (FFlag::LuauQuantifyVisitOnce)
+    {
+        DenseHashSet<void*> seen{nullptr};
+        visitTypeVarOnce(ty, q, seen);
+    }
+    else
+    {
+        visitTypeVar(ty, q);
+    }
 
     FunctionTypeVar* ftv = getMutable<FunctionTypeVar>(ty);
     LUAU_ASSERT(ftv);

Analysis/src/RequireTracer.cpp

@@ -4,182 +4,9 @@
 #include "Luau/Ast.h"
 #include "Luau/Module.h"
 
-LUAU_FASTFLAGVARIABLE(LuauTraceRequireLookupChild, false)
-LUAU_FASTFLAGVARIABLE(LuauNewRequireTrace2, false)
-
 namespace Luau
 {
 
-namespace
-{
-
-struct RequireTracerOld : AstVisitor
-{
-    explicit RequireTracerOld(FileResolver* fileResolver, const ModuleName& currentModuleName)
-        : fileResolver(fileResolver)
-        , currentModuleName(currentModuleName)
-    {
-        LUAU_ASSERT(!FFlag::LuauNewRequireTrace2);
-    }
-
-    FileResolver* const fileResolver;
-    ModuleName currentModuleName;
-    DenseHashMap<AstLocal*, ModuleName> locals{nullptr};
-    RequireTraceResult result;
-
-    std::optional<ModuleName> fromAstFragment(AstExpr* expr)
-    {
-        if (auto g = expr->as<AstExprGlobal>(); g && g->name == "script")
-            return currentModuleName;
-
-        return fileResolver->fromAstFragment(expr);
-    }
-
-    bool visit(AstStatLocal* stat) override
-    {
-        for (size_t i = 0; i < stat->vars.size; ++i)
-        {
-            AstLocal* local = stat->vars.data[i];
-
-            if (local->annotation)
-            {
-                if (AstTypeTypeof* ann = local->annotation->as<AstTypeTypeof>())
-                    ann->expr->visit(this);
-            }
-
-            if (i < stat->values.size)
-            {
-                AstExpr* expr = stat->values.data[i];
-                expr->visit(this);
-
-                const ModuleInfo* info = result.exprs.find(expr);
-                if (info)
-                    locals[local] = info->name;
-            }
-        }
-
-        return false;
-    }
-
-    bool visit(AstExprGlobal* global) override
-    {
-        std::optional<ModuleName> name = fromAstFragment(global);
-        if (name)
-            result.exprs[global] = {*name};
-
-        return false;
-    }
-
-    bool visit(AstExprLocal* local) override
-    {
-        const ModuleName* name = locals.find(local->local);
-        if (name)
-            result.exprs[local] = {*name};
-
-        return false;
-    }
-
-    bool visit(AstExprIndexName* indexName) override
-    {
-        indexName->expr->visit(this);
-
-        const ModuleInfo* info = result.exprs.find(indexName->expr);
-        if (info)
-        {
-            if (indexName->index == "parent" || indexName->index == "Parent")
-            {
-                if (auto parent = fileResolver->getParentModuleName(info->name))
-                    result.exprs[indexName] = {*parent};
-            }
-            else
-                result.exprs[indexName] = {fileResolver->concat(info->name, indexName->index.value)};
-        }
-
-        return false;
-    }
-
-    bool visit(AstExprIndexExpr* indexExpr) override
-    {
-        indexExpr->expr->visit(this);
-
-        const ModuleInfo* info = result.exprs.find(indexExpr->expr);
-        const AstExprConstantString* str = indexExpr->index->as<AstExprConstantString>();
-        if (info && str)
-        {
-            result.exprs[indexExpr] = {fileResolver->concat(info->name, std::string_view(str->value.data, str->value.size))};
-        }
-
-        indexExpr->index->visit(this);
-
-        return false;
-    }
-
-    bool visit(AstExprTypeAssertion* expr) override
-    {
-        return false;
-    }
-
-    // If we see game:GetService("StringLiteral") or Game:GetService("StringLiteral"), then rewrite to game.StringLiteral.
-    // Else traverse arguments and trace requires to them.
-    bool visit(AstExprCall* call) override
-    {
-        for (AstExpr* arg : call->args)
-            arg->visit(this);
-
-        call->func->visit(this);
-
-        AstExprGlobal* globalName = call->func->as<AstExprGlobal>();
-        if (globalName && globalName->name == "require" && call->args.size >= 1)
-        {
-            if (const ModuleInfo* moduleInfo = result.exprs.find(call->args.data[0]))
-                result.requires.push_back({moduleInfo->name, call->location});
-
-            return false;
-        }
-
-        AstExprIndexName* indexName = call->func->as<AstExprIndexName>();
-        if (!indexName)
-            return false;
-
-        std::optional<ModuleName> rootName = fromAstFragment(indexName->expr);
-
-        if (FFlag::LuauTraceRequireLookupChild && !rootName)
-        {
-            if (const ModuleInfo* moduleInfo = result.exprs.find(indexName->expr))
-                rootName = moduleInfo->name;
-        }
-
-        if (!rootName)
-            return false;
-
-        bool supportedLookup = indexName->index == "GetService" ||
-                               (FFlag::LuauTraceRequireLookupChild && (indexName->index == "FindFirstChild" || indexName->index == "WaitForChild"));
-
-        if (!supportedLookup)
-            return false;
-
-        if (call->args.size != 1)
-            return false;
-
-        AstExprConstantString* name = call->args.data[0]->as<AstExprConstantString>();
-        if (!name)
-            return false;
-
-        std::string_view v{name->value.data, name->value.size};
-        if (v.end() != std::find(v.begin(), v.end(), '/'))
-            return false;
-
-        result.exprs[call] = {fileResolver->concat(*rootName, v)};
-
-        // 'WaitForChild' can be used on modules that are not available at the typecheck time, but will be available at runtime
-        // If we fail to find such module, we will not report an UnknownRequire error
-        if (FFlag::LuauTraceRequireLookupChild && indexName->index == "WaitForChild")
-            result.exprs[call].optional = true;
-
-        return false;
-    }
-};
-
 struct RequireTracer : AstVisitor
 {
     RequireTracer(RequireTraceResult& result, FileResolver* fileResolver, const ModuleName& currentModuleName)
@@ -188,7 +15,6 @@ struct RequireTracer : AstVisitor
         , currentModuleName(currentModuleName)
         , locals(nullptr)
     {
-        LUAU_ASSERT(FFlag::LuauNewRequireTrace2);
     }
 
     bool visit(AstExprTypeAssertion* expr) override
@@ -328,24 +154,13 @@ struct RequireTracer : AstVisitor
     std::vector<AstExprCall*> requires;
 };
 
-} // anonymous namespace
-
 RequireTraceResult traceRequires(FileResolver* fileResolver, AstStatBlock* root, const ModuleName& currentModuleName)
 {
-    if (FFlag::LuauNewRequireTrace2)
+    RequireTraceResult result;
-    {
+    RequireTracer tracer{result, fileResolver, currentModuleName};
-        RequireTraceResult result;
+    root->visit(&tracer);
-        RequireTracer tracer{result, fileResolver, currentModuleName};
+    tracer.process();
-        root->visit(&tracer);
+    return result;
-        tracer.process();
-        return result;
-    }
-    else
-    {
-        RequireTracerOld tracer{fileResolver, currentModuleName};
-        root->visit(&tracer);
-        return tracer.result;
-    }
 }
 
 } // namespace Luau

Analysis/src/Substitution.cpp

@@ -7,8 +7,6 @@
 #include <stdexcept>
 
 LUAU_FASTINTVARIABLE(LuauTarjanChildLimit, 1000)
-LUAU_FASTFLAGVARIABLE(LuauSubstitutionDontReplaceIgnoredTypes, false)
-LUAU_FASTFLAG(LuauTypeAliasPacks)
 
 namespace Luau
 {
@@ -39,11 +37,8 @@ void Tarjan::visitChildren(TypeId ty, int index)
         for (TypeId itp : ttv->instantiatedTypeParams)
             visitChild(itp);
 
-        if (FFlag::LuauTypeAliasPacks)
+        for (TypePackId itp : ttv->instantiatedTypePackParams)
-        {
+            visitChild(itp);
-            for (TypePackId itp : ttv->instantiatedTypePackParams)
-                visitChild(itp);
-        }
     }
     else if (const MetatableTypeVar* mtv = get<MetatableTypeVar>(ty))
     {
@@ -339,10 +334,10 @@ std::optional<TypeId> Substitution::substitute(TypeId ty)
         return std::nullopt;
 
     for (auto [oldTy, newTy] : newTypes)
-        if (!FFlag::LuauSubstitutionDontReplaceIgnoredTypes || !ignoreChildren(oldTy))
+        if (!ignoreChildren(oldTy))
             replaceChildren(newTy);
     for (auto [oldTp, newTp] : newPacks)
-        if (!FFlag::LuauSubstitutionDontReplaceIgnoredTypes || !ignoreChildren(oldTp))
+        if (!ignoreChildren(oldTp))
             replaceChildren(newTp);
     TypeId newTy = replace(ty);
     return newTy;
@@ -359,10 +354,10 @@ std::optional<TypePackId> Substitution::substitute(TypePackId tp)
         return std::nullopt;
 
     for (auto [oldTy, newTy] : newTypes)
-        if (!FFlag::LuauSubstitutionDontReplaceIgnoredTypes || !ignoreChildren(oldTy))
+        if (!ignoreChildren(oldTy))
             replaceChildren(newTy);
     for (auto [oldTp, newTp] : newPacks)
-        if (!FFlag::LuauSubstitutionDontReplaceIgnoredTypes || !ignoreChildren(oldTp))
+        if (!ignoreChildren(oldTp))
             replaceChildren(newTp);
     TypePackId newTp = replace(tp);
     return newTp;
@@ -393,10 +388,7 @@ TypeId Substitution::clone(TypeId ty)
         clone.name = ttv->name;
         clone.syntheticName = ttv->syntheticName;
         clone.instantiatedTypeParams = ttv->instantiatedTypeParams;
-
+        clone.instantiatedTypePackParams = ttv->instantiatedTypePackParams;
-        if (FFlag::LuauTypeAliasPacks)
-            clone.instantiatedTypePackParams = ttv->instantiatedTypePackParams;
-
         clone.tags = ttv->tags;
         result = addType(std::move(clone));
     }
@@ -505,11 +497,8 @@ void Substitution::replaceChildren(TypeId ty)
         for (TypeId& itp : ttv->instantiatedTypeParams)
             itp = replace(itp);
 
-        if (FFlag::LuauTypeAliasPacks)
+        for (TypePackId& itp : ttv->instantiatedTypePackParams)
-        {
+            itp = replace(itp);
-            for (TypePackId& itp : ttv->instantiatedTypePackParams)
-                itp = replace(itp);
-        }
     }
     else if (MetatableTypeVar* mtv = getMutable<MetatableTypeVar>(ty))
     {

Analysis/src/ToDot.cpp

@@ -0,0 +1,378 @@
+// This file is part of the Luau programming language and is licensed under MIT License; see LICENSE.txt for details
+#include "Luau/ToDot.h"
+
+#include "Luau/ToString.h"
+#include "Luau/TypePack.h"
+#include "Luau/TypeVar.h"
+#include "Luau/StringUtils.h"
+
+#include <unordered_map>
+#include <unordered_set>
+
+namespace Luau
+{
+
+namespace
+{
+
+struct StateDot
+{
+    StateDot(ToDotOptions opts)
+        : opts(opts)
+    {
+    }
+
+    ToDotOptions opts;
+
+    std::unordered_set<TypeId> seenTy;
+    std::unordered_set<TypePackId> seenTp;
+    std::unordered_map<TypeId, int> tyToIndex;
+    std::unordered_map<TypePackId, int> tpToIndex;
+    int nextIndex = 1;
+    std::string result;
+
+    bool canDuplicatePrimitive(TypeId ty);
+
+    void visitChildren(TypeId ty, int index);
+    void visitChildren(TypePackId ty, int index);
+
+    void visitChild(TypeId ty, int parentIndex, const char* linkName = nullptr);
+    void visitChild(TypePackId tp, int parentIndex, const char* linkName = nullptr);
+
+    void startNode(int index);
+    void finishNode();
+
+    void startNodeLabel();
+    void finishNodeLabel(TypeId ty);
+    void finishNodeLabel(TypePackId tp);
+};
+
+bool StateDot::canDuplicatePrimitive(TypeId ty)
+{
+    if (get<BoundTypeVar>(ty))
+        return false;
+
+    return get<PrimitiveTypeVar>(ty) || get<AnyTypeVar>(ty);
+}
+
+void StateDot::visitChild(TypeId ty, int parentIndex, const char* linkName)
+{
+    if (!tyToIndex.count(ty) || (opts.duplicatePrimitives && canDuplicatePrimitive(ty)))
+        tyToIndex[ty] = nextIndex++;
+
+    int index = tyToIndex[ty];
+
+    if (parentIndex != 0)
+    {
+        if (linkName)
+            formatAppend(result, "n%d -> n%d [label=\"%s\"];\n", parentIndex, index, linkName);
+        else
+            formatAppend(result, "n%d -> n%d;\n", parentIndex, index);
+    }
+
+    if (opts.duplicatePrimitives && canDuplicatePrimitive(ty))
+    {
+        if (get<PrimitiveTypeVar>(ty))
+            formatAppend(result, "n%d [label=\"%s\"];\n", index, toStringDetailed(ty, {}).name.c_str());
+        else if (get<AnyTypeVar>(ty))
+            formatAppend(result, "n%d [label=\"any\"];\n", index);
+    }
+    else
+    {
+        visitChildren(ty, index);
+    }
+}
+
+void StateDot::visitChild(TypePackId tp, int parentIndex, const char* linkName)
+{
+    if (!tpToIndex.count(tp))
+        tpToIndex[tp] = nextIndex++;
+
+    if (parentIndex != 0)
+    {
+        if (linkName)
+            formatAppend(result, "n%d -> n%d [label=\"%s\"];\n", parentIndex, tpToIndex[tp], linkName);
+        else
+            formatAppend(result, "n%d -> n%d;\n", parentIndex, tpToIndex[tp]);
+    }
+
+    visitChildren(tp, tpToIndex[tp]);
+}
+
+void StateDot::startNode(int index)
+{
+    formatAppend(result, "n%d [", index);
+}
+
+void StateDot::finishNode()
+{
+    formatAppend(result, "];\n");
+}
+
+void StateDot::startNodeLabel()
+{
+    formatAppend(result, "label=\"");
+}
+
+void StateDot::finishNodeLabel(TypeId ty)
+{
+    if (opts.showPointers)
+        formatAppend(result, "\n0x%p", ty);
+    // additional common attributes can be added here as well
+    result += "\"";
+}
+
+void StateDot::finishNodeLabel(TypePackId tp)
+{
+    if (opts.showPointers)
+        formatAppend(result, "\n0x%p", tp);
+    // additional common attributes can be added here as well
+    result += "\"";
+}
+
+void StateDot::visitChildren(TypeId ty, int index)
+{
+    if (seenTy.count(ty))
+        return;
+    seenTy.insert(ty);
+
+    startNode(index);
+    startNodeLabel();
+
+    if (const BoundTypeVar* btv = get<BoundTypeVar>(ty))
+    {
+        formatAppend(result, "BoundTypeVar %d", index);
+        finishNodeLabel(ty);
+        finishNode();
+
+        visitChild(btv->boundTo, index);
+    }
+    else if (const FunctionTypeVar* ftv = get<FunctionTypeVar>(ty))
+    {
+        formatAppend(result, "FunctionTypeVar %d", index);
+        finishNodeLabel(ty);
+        finishNode();
+
+        visitChild(ftv->argTypes, index, "arg");
+        visitChild(ftv->retType, index, "ret");
+    }
+    else if (const TableTypeVar* ttv = get<TableTypeVar>(ty))
+    {
+        if (ttv->name)
+            formatAppend(result, "TableTypeVar %s", ttv->name->c_str());
+        else if (ttv->syntheticName)
+            formatAppend(result, "TableTypeVar %s", ttv->syntheticName->c_str());
+        else
+            formatAppend(result, "TableTypeVar %d", index);
+        finishNodeLabel(ty);
+        finishNode();
+
+        if (ttv->boundTo)
+            return visitChild(*ttv->boundTo, index, "boundTo");
+
+        for (const auto& [name, prop] : ttv->props)
+            visitChild(prop.type, index, name.c_str());
+        if (ttv->indexer)
+        {
+            visitChild(ttv->indexer->indexType, index, "[index]");
+            visitChild(ttv->indexer->indexResultType, index, "[value]");
+        }
+        for (TypeId itp : ttv->instantiatedTypeParams)
+            visitChild(itp, index, "typeParam");
+
+        for (TypePackId itp : ttv->instantiatedTypePackParams)
+            visitChild(itp, index, "typePackParam");
+    }
+    else if (const MetatableTypeVar* mtv = get<MetatableTypeVar>(ty))
+    {
+        formatAppend(result, "MetatableTypeVar %d", index);
+        finishNodeLabel(ty);
+        finishNode();
+
+        visitChild(mtv->table, index, "table");
+        visitChild(mtv->metatable, index, "metatable");
+    }
+    else if (const UnionTypeVar* utv = get<UnionTypeVar>(ty))
+    {
+        formatAppend(result, "UnionTypeVar %d", index);
+        finishNodeLabel(ty);
+        finishNode();
+
+        for (TypeId opt : utv->options)
+            visitChild(opt, index);
+    }
+    else if (const IntersectionTypeVar* itv = get<IntersectionTypeVar>(ty))
+    {
+        formatAppend(result, "IntersectionTypeVar %d", index);
+        finishNodeLabel(ty);
+        finishNode();
+
+        for (TypeId part : itv->parts)
+            visitChild(part, index);
+    }
+    else if (const GenericTypeVar* gtv = get<GenericTypeVar>(ty))
+    {
+        if (gtv->explicitName)
+            formatAppend(result, "GenericTypeVar %s", gtv->name.c_str());
+        else
+            formatAppend(result, "GenericTypeVar %d", index);
+        finishNodeLabel(ty);
+        finishNode();
+    }
+    else if (const FreeTypeVar* ftv = get<FreeTypeVar>(ty))
+    {
+        formatAppend(result, "FreeTypeVar %d", index);
+        finishNodeLabel(ty);
+        finishNode();
+    }
+    else if (get<AnyTypeVar>(ty))
+    {
+        formatAppend(result, "AnyTypeVar %d", index);
+        finishNodeLabel(ty);
+        finishNode();
+    }
+    else if (get<PrimitiveTypeVar>(ty))
+    {
+        formatAppend(result, "PrimitiveTypeVar %s", toStringDetailed(ty, {}).name.c_str());
+        finishNodeLabel(ty);
+        finishNode();
+    }
+    else if (get<ErrorTypeVar>(ty))
+    {
+        formatAppend(result, "ErrorTypeVar %d", index);
+        finishNodeLabel(ty);
+        finishNode();
+    }
+    else if (const ClassTypeVar* ctv = get<ClassTypeVar>(ty))
+    {
+        formatAppend(result, "ClassTypeVar %s", ctv->name.c_str());
+        finishNodeLabel(ty);
+        finishNode();
+
+        for (const auto& [name, prop] : ctv->props)
+            visitChild(prop.type, index, name.c_str());
+
+        if (ctv->parent)
+            visitChild(*ctv->parent, index, "[parent]");
+
+        if (ctv->metatable)
+            visitChild(*ctv->metatable, index, "[metatable]");
+    }
+    else
+    {
+        LUAU_ASSERT(!"unknown type kind");
+        finishNodeLabel(ty);
+        finishNode();
+    }
+}
+
+void StateDot::visitChildren(TypePackId tp, int index)
+{
+    if (seenTp.count(tp))
+        return;
+    seenTp.insert(tp);
+
+    startNode(index);
+    startNodeLabel();
+
+    if (const BoundTypePack* btp = get<BoundTypePack>(tp))
+    {
+        formatAppend(result, "BoundTypePack %d", index);
+        finishNodeLabel(tp);
+        finishNode();
+
+        visitChild(btp->boundTo, index);
+    }
+    else if (const TypePack* tpp = get<TypePack>(tp))
+    {
+        formatAppend(result, "TypePack %d", index);
+        finishNodeLabel(tp);
+        finishNode();
+
+        for (TypeId tv : tpp->head)
+            visitChild(tv, index);
+        if (tpp->tail)
+            visitChild(*tpp->tail, index, "tail");
+    }
+    else if (const VariadicTypePack* vtp = get<VariadicTypePack>(tp))
+    {
+        formatAppend(result, "VariadicTypePack %d", index);
+        finishNodeLabel(tp);
+        finishNode();
+
+        visitChild(vtp->ty, index);
+    }
+    else if (const FreeTypePack* ftp = get<FreeTypePack>(tp))
+    {
+        formatAppend(result, "FreeTypePack %d", index);
+        finishNodeLabel(tp);
+        finishNode();
+    }
+    else if (const GenericTypePack* gtp = get<GenericTypePack>(tp))
+    {
+        if (gtp->explicitName)
+            formatAppend(result, "GenericTypePack %s", gtp->name.c_str());
+        else
+            formatAppend(result, "GenericTypePack %d", index);
+        finishNodeLabel(tp);
+        finishNode();
+    }
+    else if (get<Unifiable::Error>(tp))
+    {
+        formatAppend(result, "ErrorTypePack %d", index);
+        finishNodeLabel(tp);
+        finishNode();
+    }
+    else
+    {
+        LUAU_ASSERT(!"unknown type pack kind");
+        finishNodeLabel(tp);
+        finishNode();
+    }
+}
+
+} // namespace
+
+std::string toDot(TypeId ty, const ToDotOptions& opts)
+{
+    StateDot state{opts};
+
+    state.result = "digraph graphname {\n";
+    state.visitChild(ty, 0);
+    state.result += "}";
+
+    return state.result;
+}
+
+std::string toDot(TypePackId tp, const ToDotOptions& opts)
+{
+    StateDot state{opts};
+
+    state.result = "digraph graphname {\n";
+    state.visitChild(tp, 0);
+    state.result += "}";
+
+    return state.result;
+}
+
+std::string toDot(TypeId ty)
+{
+    return toDot(ty, {});
+}
+
+std::string toDot(TypePackId tp)
+{
+    return toDot(tp, {});
+}
+
+void dumpDot(TypeId ty)
+{
+    printf("%s\n", toDot(ty).c_str());
+}
+
+void dumpDot(TypePackId tp)
+{
+    printf("%s\n", toDot(tp).c_str());
+}
+
+} // namespace Luau

Analysis/src/ToString.cpp

@@ -11,7 +11,7 @@
 #include <stdexcept>
 
 LUAU_FASTFLAG(LuauOccursCheckOkWithRecursiveFunctions)
-LUAU_FASTFLAG(LuauTypeAliasPacks)
+LUAU_FASTFLAGVARIABLE(LuauFunctionArgumentNameSize, false)
 
 namespace Luau
 {
@@ -59,11 +59,8 @@ struct FindCyclicTypes
             for (TypeId itp : ttv.instantiatedTypeParams)
                 visitTypeVar(itp, *this, seen);
 
-            if (FFlag::LuauTypeAliasPacks)
+            for (TypePackId itp : ttv.instantiatedTypePackParams)
-            {
+                visitTypeVar(itp, *this, seen);
-                for (TypePackId itp : ttv.instantiatedTypePackParams)
-                    visitTypeVar(itp, *this, seen);
-            }
 
             return exhaustive;
         }
@@ -248,58 +245,45 @@ struct TypeVarStringifier
 
     void stringify(const std::vector<TypeId>& types, const std::vector<TypePackId>& typePacks)
     {
-        if (types.size() == 0 && (!FFlag::LuauTypeAliasPacks || typePacks.size() == 0))
+        if (types.size() == 0 && typePacks.size() == 0)
             return;
 
-        if (types.size() || (FFlag::LuauTypeAliasPacks && typePacks.size()))
+        if (types.size() || typePacks.size())
             state.emit("<");
 
-        if (FFlag::LuauTypeAliasPacks)
+        bool first = true;
-        {
-            bool first = true;
 
-            for (TypeId ty : types)
+        for (TypeId ty : types)
-            {
+        {
-                if (!first)
+            if (!first)
-                    state.emit(", ");
+                state.emit(", ");
+            first = false;
+
+            stringify(ty);
+        }
+
+        bool singleTp = typePacks.size() == 1;
+
+        for (TypePackId tp : typePacks)
+        {
+            if (isEmpty(tp) && singleTp)
+                continue;
+
+            if (!first)
+                state.emit(", ");
+            else
                 first = false;
 
-                stringify(ty);
+            if (!singleTp)
-            }
+                state.emit("(");
 
-            bool singleTp = typePacks.size() == 1;
+            stringify(tp);
 
-            for (TypePackId tp : typePacks)
+            if (!singleTp)
-            {
+                state.emit(")");
-                if (isEmpty(tp) && singleTp)
-                    continue;
-
-                if (!first)
-                    state.emit(", ");
-                else
-                    first = false;
-
-                if (!singleTp)
-                    state.emit("(");
-
-                stringify(tp);
-
-                if (!singleTp)
-                    state.emit(")");
-            }
-        }
-        else
-        {
-            for (size_t i = 0; i < types.size(); ++i)
-            {
-                if (i > 0)
-                    state.emit(", ");
-
-                stringify(types[i]);
-            }
         }
 
-        if (types.size() || (FFlag::LuauTypeAliasPacks && typePacks.size()))
+        if (types.size() || typePacks.size())
             state.emit(">");
     }
 
@@ -767,12 +751,23 @@ struct TypePackStringifier
             else
                 state.emit(", ");
 
-            LUAU_ASSERT(elemNames.empty() || elemIndex < elemNames.size());
+            if (FFlag::LuauFunctionArgumentNameSize)
-
-            if (!elemNames.empty() && elemNames[elemIndex])
             {
-                state.emit(elemNames[elemIndex]->name);
+                if (elemIndex < elemNames.size() && elemNames[elemIndex])
-                state.emit(": ");
+                {
+                    state.emit(elemNames[elemIndex]->name);
+                    state.emit(": ");
+                }
+            }
+            else
+            {
+                LUAU_ASSERT(elemNames.empty() || elemIndex < elemNames.size());
+
+                if (!elemNames.empty() && elemNames[elemIndex])
+                {
+                    state.emit(elemNames[elemIndex]->name);
+                    state.emit(": ");
+                }
             }
             elemIndex++;
 
@@ -929,38 +924,7 @@ ToStringResult toStringDetailed(TypeId ty, const ToStringOptions& opts)
 
             result.name += ttv->name ? *ttv->name : *ttv->syntheticName;
 
-            if (FFlag::LuauTypeAliasPacks)
+            tvs.stringify(ttv->instantiatedTypeParams, ttv->instantiatedTypePackParams);
-            {
-                tvs.stringify(ttv->instantiatedTypeParams, ttv->instantiatedTypePackParams);
-            }
-            else
-            {
-                if (ttv->instantiatedTypeParams.empty() && (!FFlag::LuauTypeAliasPacks || ttv->instantiatedTypePackParams.empty()))
-                    return result;
-
-                result.name += "<";
-
-                bool first = true;
-                for (TypeId ty : ttv->instantiatedTypeParams)
-                {
-                    if (!first)
-                        result.name += ", ";
-                    else
-                        first = false;
-
-                    tvs.stringify(ty);
-                }
-
-                if (opts.maxTypeLength > 0 && result.name.length() > opts.maxTypeLength)
-                {
-                    result.truncated = true;
-                    result.name += "... <TRUNCATED>";
-                }
-                else
-                {
-                    result.name += ">";
-                }
-            }
 
             return result;
         }
@@ -1161,17 +1125,37 @@ std::string toStringNamedFunction(const std::string& prefix, const FunctionTypeV
             s += ", ";
         first = false;
 
-        // argNames is guaranteed to be equal to argTypes iff argNames is not empty.
+        if (FFlag::LuauFunctionArgumentNameSize)
-        // We don't currently respect opts.functionTypeArguments. I don't think this function should.
-        if (!ftv.argNames.empty())
-            s += (*argNameIter ? (*argNameIter)->name : "_") + ": ";
-        s += toString_(*argPackIter);
-
-        ++argPackIter;
-        if (!ftv.argNames.empty())
         {
-            LUAU_ASSERT(argNameIter != ftv.argNames.end());
+            // We don't currently respect opts.functionTypeArguments. I don't think this function should.
-            ++argNameIter;
+            if (argNameIter != ftv.argNames.end())
+            {
+                s += (*argNameIter ? (*argNameIter)->name : "_") + ": ";
+                ++argNameIter;
+            }
+            else
+            {
+                s += "_: ";
+            }
+        }
+        else
+        {
+            // argNames is guaranteed to be equal to argTypes iff argNames is not empty.
+            // We don't currently respect opts.functionTypeArguments. I don't think this function should.
+            if (!ftv.argNames.empty())
+                s += (*argNameIter ? (*argNameIter)->name : "_") + ": ";
+        }
+
+        s += toString_(*argPackIter);
+        ++argPackIter;
+
+        if (!FFlag::LuauFunctionArgumentNameSize)
+        {
+            if (!ftv.argNames.empty())
+            {
+                LUAU_ASSERT(argNameIter != ftv.argNames.end());
+                ++argNameIter;
+            }
         }
     }
 

Analysis/src/Transpiler.cpp

@@ -10,8 +10,6 @@
 #include <limits>
 #include <math.h>
 
-LUAU_FASTFLAG(LuauTypeAliasPacks)
-
 namespace
 {
 bool isIdentifierStartChar(char c)
@@ -787,7 +785,7 @@ struct Printer
 
                 writer.keyword("type");
                 writer.identifier(a->name.value);
-                if (a->generics.size > 0 || (FFlag::LuauTypeAliasPacks && a->genericPacks.size > 0))
+                if (a->generics.size > 0 || a->genericPacks.size > 0)
                 {
                     writer.symbol("<");
                     CommaSeparatorInserter comma(writer);
@@ -798,14 +796,11 @@ struct Printer
                         writer.identifier(o.value);
                     }
 
-                    if (FFlag::LuauTypeAliasPacks)
+                    for (auto o : a->genericPacks)
                     {
-                        for (auto o : a->genericPacks)
+                        comma();
-                        {
+                        writer.identifier(o.value);
-                            comma();
+                        writer.symbol("...");
-                            writer.identifier(o.value);
-                            writer.symbol("...");
-                        }
                     }
 
                     writer.symbol(">");

Analysis/src/TxnLog.cpp

@@ -5,8 +5,6 @@
 
 #include <algorithm>
 
-LUAU_FASTFLAGVARIABLE(LuauShareTxnSeen, false)
-
 namespace Luau
 {
 
@@ -36,11 +34,8 @@ void TxnLog::rollback()
     for (auto it = tableChanges.rbegin(); it != tableChanges.rend(); ++it)
         std::swap(it->first->boundTo, it->second);
 
-    if (FFlag::LuauShareTxnSeen)
+    LUAU_ASSERT(originalSeenSize <= sharedSeen->size());
-    {
+    sharedSeen->resize(originalSeenSize);
-        LUAU_ASSERT(originalSeenSize <= sharedSeen->size());
-        sharedSeen->resize(originalSeenSize);
-    }
 }
 
 void TxnLog::concat(TxnLog rhs)
@@ -53,45 +48,25 @@ void TxnLog::concat(TxnLog rhs)
 
     tableChanges.insert(tableChanges.end(), rhs.tableChanges.begin(), rhs.tableChanges.end());
     rhs.tableChanges.clear();
-
-    if (!FFlag::LuauShareTxnSeen)
-    {
-        ownedSeen.swap(rhs.ownedSeen);
-        rhs.ownedSeen.clear();
-    }
 }
 
 bool TxnLog::haveSeen(TypeId lhs, TypeId rhs)
 {
     const std::pair<TypeId, TypeId> sortedPair = (lhs > rhs) ? std::make_pair(lhs, rhs) : std::make_pair(rhs, lhs);
-    if (FFlag::LuauShareTxnSeen)
+    return (sharedSeen->end() != std::find(sharedSeen->begin(), sharedSeen->end(), sortedPair));
-        return (sharedSeen->end() != std::find(sharedSeen->begin(), sharedSeen->end(), sortedPair));
-    else
-        return (ownedSeen.end() != std::find(ownedSeen.begin(), ownedSeen.end(), sortedPair));
 }
 
 void TxnLog::pushSeen(TypeId lhs, TypeId rhs)
 {
     const std::pair<TypeId, TypeId> sortedPair = (lhs > rhs) ? std::make_pair(lhs, rhs) : std::make_pair(rhs, lhs);
-    if (FFlag::LuauShareTxnSeen)
+    sharedSeen->push_back(sortedPair);
-        sharedSeen->push_back(sortedPair);
-    else
-        ownedSeen.push_back(sortedPair);
 }
 
 void TxnLog::popSeen(TypeId lhs, TypeId rhs)
 {
     const std::pair<TypeId, TypeId> sortedPair = (lhs > rhs) ? std::make_pair(lhs, rhs) : std::make_pair(rhs, lhs);
-    if (FFlag::LuauShareTxnSeen)
+    LUAU_ASSERT(sortedPair == sharedSeen->back());
-    {
+    sharedSeen->pop_back();
-        LUAU_ASSERT(sortedPair == sharedSeen->back());
-        sharedSeen->pop_back();
-    }
-    else
-    {
-        LUAU_ASSERT(sortedPair == ownedSeen.back());
-        ownedSeen.pop_back();
-    }
 }
 
 } // namespace Luau

Analysis/src/TypeAttach.cpp

@@ -13,8 +13,6 @@
 
 #include <string>
 
-LUAU_FASTFLAG(LuauTypeAliasPacks)
-
 static char* allocateString(Luau::Allocator& allocator, std::string_view contents)
 {
     char* result = (char*)allocator.allocate(contents.size() + 1);
@@ -131,12 +129,9 @@ public:
                 parameters.data[i] = {Luau::visit(*this, ttv.instantiatedTypeParams[i]->ty), {}};
             }
 
-            if (FFlag::LuauTypeAliasPacks)
+            for (size_t i = 0; i < ttv.instantiatedTypePackParams.size(); ++i)
             {
-                for (size_t i = 0; i < ttv.instantiatedTypePackParams.size(); ++i)
+                parameters.data[i] = {{}, rehydrate(ttv.instantiatedTypePackParams[i])};
-                {
-                    parameters.data[i] = {{}, rehydrate(ttv.instantiatedTypePackParams[i])};
-                }
             }
 
             return allocator->alloc<AstTypeReference>(Location(), std::nullopt, AstName(ttv.name->c_str()), parameters.size != 0, parameters);
@@ -250,20 +245,7 @@ public:
 
         AstTypePack* argTailAnnotation = nullptr;
         if (argTail)
-        {
+            argTailAnnotation = rehydrate(*argTail);
-            if (FFlag::LuauTypeAliasPacks)
-            {
-                argTailAnnotation = rehydrate(*argTail);
-            }
-            else
-            {
-                TypePackId tail = *argTail;
-                if (const VariadicTypePack* vtp = get<VariadicTypePack>(tail))
-                {
-                    argTailAnnotation = allocator->alloc<AstTypePackVariadic>(Location(), Luau::visit(*this, vtp->ty->ty));
-                }
-            }
-        }
 
         AstArray<std::optional<AstArgumentName>> argNames;
         argNames.size = ftv.argNames.size();
@@ -292,20 +274,7 @@ public:
 
         AstTypePack* retTailAnnotation = nullptr;
         if (retTail)
-        {
+            retTailAnnotation = rehydrate(*retTail);
-            if (FFlag::LuauTypeAliasPacks)
-            {
-                retTailAnnotation = rehydrate(*retTail);
-            }
-            else
-            {
-                TypePackId tail = *retTail;
-                if (const VariadicTypePack* vtp = get<VariadicTypePack>(tail))
-                {
-                    retTailAnnotation = allocator->alloc<AstTypePackVariadic>(Location(), Luau::visit(*this, vtp->ty->ty));
-                }
-            }
-        }
 
         return allocator->alloc<AstTypeFunction>(
             Location(), generics, genericPacks, AstTypeList{argTypes, argTailAnnotation}, argNames, AstTypeList{returnTypes, retTailAnnotation});
@@ -518,18 +487,7 @@ public:
                 const auto& [v, tail] = flatten(ret);
 
                 if (tail)
-                {
+                    variadicAnnotation = TypeRehydrationVisitor(allocator, &syntheticNames).rehydrate(*tail);
-                    if (FFlag::LuauTypeAliasPacks)
-                    {
-                        variadicAnnotation = TypeRehydrationVisitor(allocator, &syntheticNames).rehydrate(*tail);
-                    }
-                    else
-                    {
-                        TypePackId tailPack = *tail;
-                        if (const VariadicTypePack* vtp = get<VariadicTypePack>(tailPack))
-                            variadicAnnotation = allocator->alloc<AstTypePackVariadic>(Location(), typeAst(vtp->ty));
-                    }
-                }
 
                 fn->returnAnnotation = AstTypeList{typeAstPack(ret), variadicAnnotation};
             }

Analysis/src/TypeInfer.cpp

@@ -23,22 +23,20 @@ LUAU_FASTINTVARIABLE(LuauTypeInferRecursionLimit, 500)
 LUAU_FASTINTVARIABLE(LuauTypeInferTypePackLoopLimit, 5000)
 LUAU_FASTINTVARIABLE(LuauCheckRecursionLimit, 500)
 LUAU_FASTFLAG(LuauKnowsTheDataModel3)
-LUAU_FASTFLAGVARIABLE(LuauClassPropertyAccessAsString, false)
 LUAU_FASTFLAGVARIABLE(LuauEqConstraint, false)
 LUAU_FASTFLAGVARIABLE(LuauWeakEqConstraint, false) // Eventually removed as false.
-LUAU_FASTFLAG(LuauTraceRequireLookupChild)
 LUAU_FASTFLAGVARIABLE(LuauCloneCorrectlyBeforeMutatingTableType, false)
 LUAU_FASTFLAGVARIABLE(LuauStoreMatchingOverloadFnType, false)
 LUAU_FASTFLAGVARIABLE(LuauRecursiveTypeParameterRestriction, false)
 LUAU_FASTFLAGVARIABLE(LuauIfElseExpressionAnalysisSupport, false)
 LUAU_FASTFLAGVARIABLE(LuauStrictRequire, false)
-LUAU_FASTFLAG(LuauSubstitutionDontReplaceIgnoredTypes)
 LUAU_FASTFLAGVARIABLE(LuauQuantifyInPlace2, false)
-LUAU_FASTFLAG(LuauNewRequireTrace2)
-LUAU_FASTFLAG(LuauTypeAliasPacks)
 LUAU_FASTFLAGVARIABLE(LuauSingletonTypes, false)
 LUAU_FASTFLAGVARIABLE(LuauExpectedTypesOfProperties, false)
 LUAU_FASTFLAGVARIABLE(LuauErrorRecoveryType, false)
+LUAU_FASTFLAGVARIABLE(LuauPropertiesGetExpectedType, false)
+LUAU_FASTFLAGVARIABLE(LuauTailArgumentTypeInfo, false)
+LUAU_FASTFLAGVARIABLE(LuauModuleRequireErrorPack, false)
 
 namespace Luau
 {
@@ -562,12 +560,6 @@ ErrorVec TypeChecker::canUnify(TypePackId left, TypePackId right, const Location
     return canUnify_(left, right, location);
 }
 
-ErrorVec TypeChecker::canUnify(const std::vector<std::pair<TypeId, TypeId>>& seen, TypeId superTy, TypeId subTy, const Location& location)
-{
-    Unifier state = mkUnifier(seen, location);
-    return state.canUnify(superTy, subTy);
-}
-
 template<typename Id>
 ErrorVec TypeChecker::canUnify_(Id superTy, Id subTy, const Location& location)
 {
@@ -1152,61 +1144,20 @@ void TypeChecker::check(const ScopePtr& scope, const AstStatTypeAlias& typealias
             Location location = scope->typeAliasLocations[name];
             reportError(TypeError{typealias.location, DuplicateTypeDefinition{name, location}});
 
-            if (FFlag::LuauTypeAliasPacks)
+            bindingsMap[name] = TypeFun{binding->typeParams, binding->typePackParams, errorRecoveryType(anyType)};
-                bindingsMap[name] = TypeFun{binding->typeParams, binding->typePackParams, errorRecoveryType(anyType)};
-            else
-                bindingsMap[name] = TypeFun{binding->typeParams, errorRecoveryType(anyType)};
         }
         else
         {
             ScopePtr aliasScope =
                 FFlag::LuauQuantifyInPlace2 ? childScope(scope, typealias.location, subLevel) : childScope(scope, typealias.location);
 
-            if (FFlag::LuauTypeAliasPacks)
+            auto [generics, genericPacks] = createGenericTypes(aliasScope, scope->level, typealias, typealias.generics, typealias.genericPacks);
-            {
-                auto [generics, genericPacks] = createGenericTypes(aliasScope, scope->level, typealias, typealias.generics, typealias.genericPacks);
 
-                TypeId ty = freshType(aliasScope);
+            TypeId ty = freshType(aliasScope);
-                FreeTypeVar* ftv = getMutable<FreeTypeVar>(ty);
+            FreeTypeVar* ftv = getMutable<FreeTypeVar>(ty);
-                LUAU_ASSERT(ftv);
+            LUAU_ASSERT(ftv);
-                ftv->forwardedTypeAlias = true;
+            ftv->forwardedTypeAlias = true;
-                bindingsMap[name] = {std::move(generics), std::move(genericPacks), ty};
+            bindingsMap[name] = {std::move(generics), std::move(genericPacks), ty};
-            }
-            else
-            {
-                std::vector<TypeId> generics;
-                for (AstName generic : typealias.generics)
-                {
-                    Name n = generic.value;
-
-                    // These generics are the only thing that will ever be added to aliasScope, so we can be certain that
-                    // a collision can only occur when two generic typevars have the same name.
-                    if (aliasScope->privateTypeBindings.end() != aliasScope->privateTypeBindings.find(n))
-                    {
-                        // TODO(jhuelsman): report the exact span of the generic type parameter whose name is a duplicate.
-                        reportError(TypeError{typealias.location, DuplicateGenericParameter{n}});
-                    }
-
-                    TypeId g;
-                    if (FFlag::LuauRecursiveTypeParameterRestriction)
-                    {
-                        TypeId& cached = scope->typeAliasTypeParameters[n];
-                        if (!cached)
-                            cached = addType(GenericTypeVar{aliasScope->level, n});
-                        g = cached;
-                    }
-                    else
-                        g = addType(GenericTypeVar{aliasScope->level, n});
-                    generics.push_back(g);
-                    aliasScope->privateTypeBindings[n] = TypeFun{{}, g};
-                }
-
-                TypeId ty = freshType(aliasScope);
-                FreeTypeVar* ftv = getMutable<FreeTypeVar>(ty);
-                LUAU_ASSERT(ftv);
-                ftv->forwardedTypeAlias = true;
-                bindingsMap[name] = {std::move(generics), ty};
-            }
         }
     }
     else
@@ -1223,14 +1174,11 @@ void TypeChecker::check(const ScopePtr& scope, const AstStatTypeAlias& typealias
             aliasScope->privateTypeBindings[generic->name] = TypeFun{{}, ty};
         }
 
-        if (FFlag::LuauTypeAliasPacks)
+        for (TypePackId tp : binding->typePackParams)
         {
-            for (TypePackId tp : binding->typePackParams)
+            auto generic = get<GenericTypePack>(tp);
-            {
+            LUAU_ASSERT(generic);
-                auto generic = get<GenericTypePack>(tp);
+            aliasScope->privateTypePackBindings[generic->name] = tp;
-                LUAU_ASSERT(generic);
-                aliasScope->privateTypePackBindings[generic->name] = tp;
-            }
         }
 
         TypeId ty = resolveType(aliasScope, *typealias.type);
@@ -1241,19 +1189,16 @@ void TypeChecker::check(const ScopePtr& scope, const AstStatTypeAlias& typealias
             {
                 // Copy can be skipped if this is an identical alias
                 if (ttv->name != name || ttv->instantiatedTypeParams != binding->typeParams ||
-                    (FFlag::LuauTypeAliasPacks && ttv->instantiatedTypePackParams != binding->typePackParams))
+                    ttv->instantiatedTypePackParams != binding->typePackParams)
                 {
                     // This is a shallow clone, original recursive links to self are not updated
                     TableTypeVar clone = TableTypeVar{ttv->props, ttv->indexer, ttv->level, ttv->state};
 
                     clone.methodDefinitionLocations = ttv->methodDefinitionLocations;
                     clone.definitionModuleName = ttv->definitionModuleName;
-
                     clone.name = name;
                     clone.instantiatedTypeParams = binding->typeParams;
-
+                    clone.instantiatedTypePackParams = binding->typePackParams;
-                    if (FFlag::LuauTypeAliasPacks)
-                        clone.instantiatedTypePackParams = binding->typePackParams;
 
                     ty = addType(std::move(clone));
                 }
@@ -1262,9 +1207,7 @@ void TypeChecker::check(const ScopePtr& scope, const AstStatTypeAlias& typealias
             {
                 ttv->name = name;
                 ttv->instantiatedTypeParams = binding->typeParams;
-
+                ttv->instantiatedTypePackParams = binding->typePackParams;
-                if (FFlag::LuauTypeAliasPacks)
-                    ttv->instantiatedTypePackParams = binding->typePackParams;
             }
         }
         else if (auto mtv = getMutable<MetatableTypeVar>(follow(ty)))
@@ -1289,7 +1232,7 @@ void TypeChecker::check(const ScopePtr& scope, const AstStatDeclareClass& declar
         }
 
         // We don't have generic classes, so this assertion _should_ never be hit.
-        LUAU_ASSERT(lookupType->typeParams.size() == 0 && (!FFlag::LuauTypeAliasPacks || lookupType->typePackParams.size() == 0));
+        LUAU_ASSERT(lookupType->typeParams.size() == 0 && lookupType->typePackParams.size() == 0);
         superTy = lookupType->type;
 
         if (!get<ClassTypeVar>(follow(*superTy)))
@@ -1851,6 +1794,24 @@ TypeId TypeChecker::checkExprTable(
                 if (isNonstrictMode() && !getTableType(exprType) && !get<FunctionTypeVar>(exprType))
                     exprType = anyType;
 
+                if (FFlag::LuauPropertiesGetExpectedType && expectedTable)
+                {
+                    auto it = expectedTable->props.find(key->value.data);
+                    if (it != expectedTable->props.end())
+                    {
+                        Property expectedProp = it->second;
+                        ErrorVec errors = tryUnify(expectedProp.type, exprType, k->location);
+                        if (errors.empty())
+                            exprType = expectedProp.type;
+                    }
+                    else if (expectedTable->indexer && isString(expectedTable->indexer->indexType))
+                    {
+                        ErrorVec errors = tryUnify(expectedTable->indexer->indexResultType, exprType, k->location);
+                        if (errors.empty())
+                            exprType = expectedTable->indexer->indexResultType;
+                    }
+                }
+
                 props[key->value.data] = {exprType, /* deprecated */ false, {}, k->location};
             }
             else
@@ -3744,17 +3705,29 @@ ExprResult<TypePackId> TypeChecker::checkExprList(const ScopePtr& scope, const L
     for (size_t i = 0; i < exprs.size; ++i)
     {
         AstExpr* expr = exprs.data[i];
+        std::optional<TypeId> expectedType = i < expectedTypes.size() ? expectedTypes[i] : std::nullopt;
 
         if (i == lastIndex && (expr->is<AstExprCall>() || expr->is<AstExprVarargs>()))
         {
             auto [typePack, exprPredicates] = checkExprPack(scope, *expr);
             insert(exprPredicates);
 
+            if (FFlag::LuauTailArgumentTypeInfo)
+            {
+                if (std::optional<TypeId> firstTy = first(typePack))
+                {
+                    if (!currentModule->astTypes.find(expr))
+                        currentModule->astTypes[expr] = follow(*firstTy);
+                }
+
+                if (expectedType)
+                    currentModule->astExpectedTypes[expr] = *expectedType;
+            }
+
             tp->tail = typePack;
         }
         else
         {
-            std::optional<TypeId> expectedType = i < expectedTypes.size() ? expectedTypes[i] : std::nullopt;
             auto [type, exprPredicates] = checkExpr(scope, *expr, expectedType);
             insert(exprPredicates);
 
@@ -3797,7 +3770,7 @@ TypeId TypeChecker::checkRequire(const ScopePtr& scope, const ModuleInfo& module
     LUAU_TIMETRACE_SCOPE("TypeChecker::checkRequire", "TypeChecker");
     LUAU_TIMETRACE_ARGUMENT("moduleInfo", moduleInfo.name.c_str());
 
-    if (FFlag::LuauNewRequireTrace2 && moduleInfo.name.empty())
+    if (moduleInfo.name.empty())
     {
         if (FFlag::LuauStrictRequire && currentModule->mode == Mode::Strict)
         {
@@ -3814,7 +3787,7 @@ TypeId TypeChecker::checkRequire(const ScopePtr& scope, const ModuleInfo& module
         // There are two reasons why we might fail to find the module:
         // either the file does not exist or there's a cycle. If there's a cycle
         // we will already have reported the error.
-        if (!resolver->moduleExists(moduleInfo.name) && (FFlag::LuauTraceRequireLookupChild ? !moduleInfo.optional : true))
+        if (!resolver->moduleExists(moduleInfo.name) && !moduleInfo.optional)
         {
             std::string reportedModulePath = resolver->getHumanReadableModuleName(moduleInfo.name);
             reportError(TypeError{location, UnknownRequire{reportedModulePath}});
@@ -3830,7 +3803,12 @@ TypeId TypeChecker::checkRequire(const ScopePtr& scope, const ModuleInfo& module
         return errorRecoveryType(scope);
     }
 
-    std::optional<TypeId> moduleType = first(module->getModuleScope()->returnType);
+    TypePackId modulePack = module->getModuleScope()->returnType;
+
+    if (FFlag::LuauModuleRequireErrorPack && get<Unifiable::Error>(modulePack))
+        return errorRecoveryType(scope);
+
+    std::optional<TypeId> moduleType = first(modulePack);
     if (!moduleType)
     {
         std::string humanReadableName = resolver->getHumanReadableModuleName(moduleInfo.name);
@@ -3840,7 +3818,8 @@ TypeId TypeChecker::checkRequire(const ScopePtr& scope, const ModuleInfo& module
 
     SeenTypes seenTypes;
     SeenTypePacks seenTypePacks;
-    return clone(*moduleType, currentModule->internalTypes, seenTypes, seenTypePacks);
+    CloneState cloneState;
+    return clone(*moduleType, currentModule->internalTypes, seenTypes, seenTypePacks, cloneState);
 }
 
 void TypeChecker::tablify(TypeId type)
@@ -4326,11 +4305,6 @@ Unifier TypeChecker::mkUnifier(const Location& location)
     return Unifier{&currentModule->internalTypes, currentModule->mode, globalScope, location, Variance::Covariant, unifierState};
 }
 
-Unifier TypeChecker::mkUnifier(const std::vector<std::pair<TypeId, TypeId>>& seen, const Location& location)
-{
-    return Unifier{&currentModule->internalTypes, currentModule->mode, globalScope, seen, location, Variance::Covariant, unifierState};
-}
-
 TypeId TypeChecker::freshType(const ScopePtr& scope)
 {
     return freshType(scope->level);
@@ -4477,117 +4451,82 @@ TypeId TypeChecker::resolveType(const ScopePtr& scope, const AstType& annotation
             return errorRecoveryType(scope);
         }
 
-        if (lit->parameters.size == 0 && tf->typeParams.empty() && (!FFlag::LuauTypeAliasPacks || tf->typePackParams.empty()))
+        if (lit->parameters.size == 0 && tf->typeParams.empty() && tf->typePackParams.empty())
-        {
             return tf->type;
-        }
+
-        else if (!FFlag::LuauTypeAliasPacks && lit->parameters.size != tf->typeParams.size())
+        if (!lit->hasParameterList && !tf->typePackParams.empty())
         {
-            reportError(TypeError{annotation.location, IncorrectGenericParameterCount{lit->name.value, *tf, lit->parameters.size, 0}});
+            reportError(TypeError{annotation.location, GenericError{"Type parameter list is required"}});
             if (!FFlag::LuauErrorRecoveryType)
                 return errorRecoveryType(scope);
         }
 
-        if (FFlag::LuauTypeAliasPacks)
+        std::vector<TypeId> typeParams;
+        std::vector<TypeId> extraTypes;
+        std::vector<TypePackId> typePackParams;
+
+        for (size_t i = 0; i < lit->parameters.size; ++i)
         {
-            if (!lit->hasParameterList && !tf->typePackParams.empty())
+            if (AstType* type = lit->parameters.data[i].type)
             {
-                reportError(TypeError{annotation.location, GenericError{"Type parameter list is required"}});
+                TypeId ty = resolveType(scope, *type);
-                if (!FFlag::LuauErrorRecoveryType)
-                    return errorRecoveryType(scope);
-            }
 
-            std::vector<TypeId> typeParams;
+                if (typeParams.size() < tf->typeParams.size() || tf->typePackParams.empty())
-            std::vector<TypeId> extraTypes;
+                    typeParams.push_back(ty);
-            std::vector<TypePackId> typePackParams;
+                else if (typePackParams.empty())
-
+                    extraTypes.push_back(ty);
-            for (size_t i = 0; i < lit->parameters.size; ++i)
-            {
-                if (AstType* type = lit->parameters.data[i].type)
-                {
-                    TypeId ty = resolveType(scope, *type);
-
-                    if (typeParams.size() < tf->typeParams.size() || tf->typePackParams.empty())
-                        typeParams.push_back(ty);
-                    else if (typePackParams.empty())
-                        extraTypes.push_back(ty);
-                    else
-                        reportError(TypeError{annotation.location, GenericError{"Type parameters must come before type pack parameters"}});
-                }
-                else if (AstTypePack* typePack = lit->parameters.data[i].typePack)
-                {
-                    TypePackId tp = resolveTypePack(scope, *typePack);
-
-                    // If we have collected an implicit type pack, materialize it
-                    if (typePackParams.empty() && !extraTypes.empty())
-                        typePackParams.push_back(addTypePack(extraTypes));
-
-                    // If we need more regular types, we can use single element type packs to fill those in
-                    if (typeParams.size() < tf->typeParams.size() && size(tp) == 1 && finite(tp) && first(tp))
-                        typeParams.push_back(*first(tp));
-                    else
-                        typePackParams.push_back(tp);
-                }
-            }
-
-            // If we still haven't meterialized an implicit type pack, do it now
-            if (typePackParams.empty() && !extraTypes.empty())
-                typePackParams.push_back(addTypePack(extraTypes));
-
-            // If we didn't combine regular types into a type pack and we're still one type pack short, provide an empty type pack
-            if (extraTypes.empty() && typePackParams.size() + 1 == tf->typePackParams.size())
-                typePackParams.push_back(addTypePack({}));
-
-            if (typeParams.size() != tf->typeParams.size() || typePackParams.size() != tf->typePackParams.size())
-            {
-                reportError(
-                    TypeError{annotation.location, IncorrectGenericParameterCount{lit->name.value, *tf, typeParams.size(), typePackParams.size()}});
-
-                if (FFlag::LuauErrorRecoveryType)
-                {
-                    // Pad the types out with error recovery types
-                    while (typeParams.size() < tf->typeParams.size())
-                        typeParams.push_back(errorRecoveryType(scope));
-                    while (typePackParams.size() < tf->typePackParams.size())
-                        typePackParams.push_back(errorRecoveryTypePack(scope));
-                }
                 else
-                    return errorRecoveryType(scope);
+                    reportError(TypeError{annotation.location, GenericError{"Type parameters must come before type pack parameters"}});
             }
-
+            else if (AstTypePack* typePack = lit->parameters.data[i].typePack)
-            if (FFlag::LuauRecursiveTypeParameterRestriction && typeParams == tf->typeParams && typePackParams == tf->typePackParams)
             {
-                // If the generic parameters and the type arguments are the same, we are about to
+                TypePackId tp = resolveTypePack(scope, *typePack);
-                // perform an identity substitution, which we can just short-circuit.
+
-                return tf->type;
+                // If we have collected an implicit type pack, materialize it
+                if (typePackParams.empty() && !extraTypes.empty())
+                    typePackParams.push_back(addTypePack(extraTypes));
+
+                // If we need more regular types, we can use single element type packs to fill those in
+                if (typeParams.size() < tf->typeParams.size() && size(tp) == 1 && finite(tp) && first(tp))
+                    typeParams.push_back(*first(tp));
+                else
+                    typePackParams.push_back(tp);
             }
-
-            return instantiateTypeFun(scope, *tf, typeParams, typePackParams, annotation.location);
         }
-        else
-        {
-            std::vector<TypeId> typeParams;
 
-            for (const auto& param : lit->parameters)
+        // If we still haven't meterialized an implicit type pack, do it now
-                typeParams.push_back(resolveType(scope, *param.type));
+        if (typePackParams.empty() && !extraTypes.empty())
+            typePackParams.push_back(addTypePack(extraTypes));
+
+        // If we didn't combine regular types into a type pack and we're still one type pack short, provide an empty type pack
+        if (extraTypes.empty() && typePackParams.size() + 1 == tf->typePackParams.size())
+            typePackParams.push_back(addTypePack({}));
+
+        if (typeParams.size() != tf->typeParams.size() || typePackParams.size() != tf->typePackParams.size())
+        {
+            reportError(
+                TypeError{annotation.location, IncorrectGenericParameterCount{lit->name.value, *tf, typeParams.size(), typePackParams.size()}});
 
             if (FFlag::LuauErrorRecoveryType)
             {
-                // If there aren't enough type parameters, pad them out with error recovery types
+                // Pad the types out with error recovery types
-                // (we've already reported the error)
+                while (typeParams.size() < tf->typeParams.size())
-                while (typeParams.size() < lit->parameters.size)
                     typeParams.push_back(errorRecoveryType(scope));
+                while (typePackParams.size() < tf->typePackParams.size())
+                    typePackParams.push_back(errorRecoveryTypePack(scope));
             }
-
+            else
-            if (FFlag::LuauRecursiveTypeParameterRestriction && typeParams == tf->typeParams)
+                return errorRecoveryType(scope);
-            {
-                // If the generic parameters and the type arguments are the same, we are about to
-                // perform an identity substitution, which we can just short-circuit.
-                return tf->type;
-            }
-
-            return instantiateTypeFun(scope, *tf, typeParams, {}, annotation.location);
         }
+
+        if (FFlag::LuauRecursiveTypeParameterRestriction && typeParams == tf->typeParams && typePackParams == tf->typePackParams)
+        {
+            // If the generic parameters and the type arguments are the same, we are about to
+            // perform an identity substitution, which we can just short-circuit.
+            return tf->type;
+        }
+
+        return instantiateTypeFun(scope, *tf, typeParams, typePackParams, annotation.location);
     }
     else if (const auto& table = annotation.as<AstTypeTable>())
     {
@@ -4757,7 +4696,7 @@ bool ApplyTypeFunction::isDirty(TypePackId tp)
 
 bool ApplyTypeFunction::ignoreChildren(TypeId ty)
 {
-    if (FFlag::LuauSubstitutionDontReplaceIgnoredTypes && get<GenericTypeVar>(ty))
+    if (get<GenericTypeVar>(ty))
         return true;
     else
         return false;
@@ -4765,7 +4704,7 @@ bool ApplyTypeFunction::ignoreChildren(TypeId ty)
 
 bool ApplyTypeFunction::ignoreChildren(TypePackId tp)
 {
-    if (FFlag::LuauSubstitutionDontReplaceIgnoredTypes && get<GenericTypePack>(tp))
+    if (get<GenericTypePack>(tp))
         return true;
     else
         return false;
@@ -4788,36 +4727,26 @@ TypePackId ApplyTypeFunction::clean(TypePackId tp)
     // Really this should just replace the arguments,
     // but for bug-compatibility with existing code, we replace
     // all generics by free type variables.
-    if (FFlag::LuauTypeAliasPacks)
+    TypePackId& arg = typePackArguments[tp];
-    {
+    if (arg)
-        TypePackId& arg = typePackArguments[tp];
+        return arg;
-        if (arg)
-            return arg;
-        else
-            return addTypePack(FreeTypePack{level});
-    }
     else
-    {
         return addTypePack(FreeTypePack{level});
-    }
 }
 
 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() && (!FFlag::LuauTypeAliasPacks || tf.typePackParams.empty()))
+    if (tf.typeParams.empty() && tf.typePackParams.empty())
         return tf.type;
 
     applyTypeFunction.typeArguments.clear();
     for (size_t i = 0; i < tf.typeParams.size(); ++i)
         applyTypeFunction.typeArguments[tf.typeParams[i]] = typeParams[i];
 
-    if (FFlag::LuauTypeAliasPacks)
+    applyTypeFunction.typePackArguments.clear();
-    {
+    for (size_t i = 0; i < tf.typePackParams.size(); ++i)
-        applyTypeFunction.typePackArguments.clear();
+        applyTypeFunction.typePackArguments[tf.typePackParams[i]] = typePackParams[i];
-        for (size_t i = 0; i < tf.typePackParams.size(); ++i)
-            applyTypeFunction.typePackArguments[tf.typePackParams[i]] = typePackParams[i];
-    }
 
     applyTypeFunction.currentModule = currentModule;
     applyTypeFunction.level = scope->level;
@@ -4866,9 +4795,7 @@ TypeId TypeChecker::instantiateTypeFun(const ScopePtr& scope, const TypeFun& tf,
         if (ttv)
         {
             ttv->instantiatedTypeParams = typeParams;
-
+            ttv->instantiatedTypePackParams = typePackParams;
-            if (FFlag::LuauTypeAliasPacks)
-                ttv->instantiatedTypePackParams = typePackParams;
         }
     }
     else
@@ -4884,9 +4811,7 @@ TypeId TypeChecker::instantiateTypeFun(const ScopePtr& scope, const TypeFun& tf,
             }
 
             ttv->instantiatedTypeParams = typeParams;
-
+            ttv->instantiatedTypePackParams = typePackParams;
-            if (FFlag::LuauTypeAliasPacks)
-                ttv->instantiatedTypePackParams = typePackParams;
         }
     }
 
@@ -4914,7 +4839,7 @@ std::pair<std::vector<TypeId>, std::vector<TypePackId>> TypeChecker::createGener
         }
 
         TypeId g;
-        if (FFlag::LuauRecursiveTypeParameterRestriction && FFlag::LuauTypeAliasPacks)
+        if (FFlag::LuauRecursiveTypeParameterRestriction)
         {
             TypeId& cached = scope->parent->typeAliasTypeParameters[n];
             if (!cached)
@@ -4944,7 +4869,7 @@ std::pair<std::vector<TypeId>, std::vector<TypePackId>> TypeChecker::createGener
         }
 
         TypePackId g;
-        if (FFlag::LuauRecursiveTypeParameterRestriction && FFlag::LuauTypeAliasPacks)
+        if (FFlag::LuauRecursiveTypeParameterRestriction)
         {
             TypePackId& cached = scope->parent->typeAliasTypePackParameters[n];
             if (!cached)
@@ -5245,7 +5170,7 @@ void TypeChecker::resolve(const TypeGuardPredicate& typeguardP, ErrorVec& errVec
         return fail(UnknownSymbol{typeguardP.kind, UnknownSymbol::Type});
 
     auto typeFun = globalScope->lookupType(typeguardP.kind);
-    if (!typeFun || !typeFun->typeParams.empty() || (FFlag::LuauTypeAliasPacks && !typeFun->typePackParams.empty()))
+    if (!typeFun || !typeFun->typeParams.empty() || !typeFun->typePackParams.empty())
         return fail(UnknownSymbol{typeguardP.kind, UnknownSymbol::Type});
 
     TypeId type = follow(typeFun->type);

Analysis/src/TypeVar.cpp

@@ -19,7 +19,6 @@
 
 LUAU_FASTINTVARIABLE(LuauTypeMaximumStringifierLength, 500)
 LUAU_FASTINTVARIABLE(LuauTableTypeMaximumStringifierLength, 0)
-LUAU_FASTFLAG(LuauTypeAliasPacks)
 LUAU_FASTFLAGVARIABLE(LuauRefactorTagging, false)
 LUAU_FASTFLAG(LuauErrorRecoveryType)
 
@@ -739,369 +738,6 @@ void persist(TypePackId tp)
     }
 }
 
-namespace
-{
-
-struct StateDot
-{
-    StateDot(ToDotOptions opts)
-        : opts(opts)
-    {
-    }
-
-    ToDotOptions opts;
-
-    std::unordered_set<TypeId> seenTy;
-    std::unordered_set<TypePackId> seenTp;
-    std::unordered_map<TypeId, int> tyToIndex;
-    std::unordered_map<TypePackId, int> tpToIndex;
-    int nextIndex = 1;
-    std::string result;
-
-    bool canDuplicatePrimitive(TypeId ty);
-
-    void visitChildren(TypeId ty, int index);
-    void visitChildren(TypePackId ty, int index);
-
-    void visitChild(TypeId ty, int parentIndex, const char* linkName = nullptr);
-    void visitChild(TypePackId tp, int parentIndex, const char* linkName = nullptr);
-
-    void startNode(int index);
-    void finishNode();
-
-    void startNodeLabel();
-    void finishNodeLabel(TypeId ty);
-    void finishNodeLabel(TypePackId tp);
-};
-
-bool StateDot::canDuplicatePrimitive(TypeId ty)
-{
-    if (get<BoundTypeVar>(ty))
-        return false;
-
-    return get<PrimitiveTypeVar>(ty) || get<AnyTypeVar>(ty);
-}
-
-void StateDot::visitChild(TypeId ty, int parentIndex, const char* linkName)
-{
-    if (!tyToIndex.count(ty) || (opts.duplicatePrimitives && canDuplicatePrimitive(ty)))
-        tyToIndex[ty] = nextIndex++;
-
-    int index = tyToIndex[ty];
-
-    if (parentIndex != 0)
-    {
-        if (linkName)
-            formatAppend(result, "n%d -> n%d [label=\"%s\"];\n", parentIndex, index, linkName);
-        else
-            formatAppend(result, "n%d -> n%d;\n", parentIndex, index);
-    }
-
-    if (opts.duplicatePrimitives && canDuplicatePrimitive(ty))
-    {
-        if (get<PrimitiveTypeVar>(ty))
-            formatAppend(result, "n%d [label=\"%s\"];\n", index, toStringDetailed(ty, {}).name.c_str());
-        else if (get<AnyTypeVar>(ty))
-            formatAppend(result, "n%d [label=\"any\"];\n", index);
-    }
-    else
-    {
-        visitChildren(ty, index);
-    }
-}
-
-void StateDot::visitChild(TypePackId tp, int parentIndex, const char* linkName)
-{
-    if (!tpToIndex.count(tp))
-        tpToIndex[tp] = nextIndex++;
-
-    if (linkName)
-        formatAppend(result, "n%d -> n%d [label=\"%s\"];\n", parentIndex, tpToIndex[tp], linkName);
-    else
-        formatAppend(result, "n%d -> n%d;\n", parentIndex, tpToIndex[tp]);
-
-    visitChildren(tp, tpToIndex[tp]);
-}
-
-void StateDot::startNode(int index)
-{
-    formatAppend(result, "n%d [", index);
-}
-
-void StateDot::finishNode()
-{
-    formatAppend(result, "];\n");
-}
-
-void StateDot::startNodeLabel()
-{
-    formatAppend(result, "label=\"");
-}
-
-void StateDot::finishNodeLabel(TypeId ty)
-{
-    if (opts.showPointers)
-        formatAppend(result, "\n0x%p", ty);
-    // additional common attributes can be added here as well
-    result += "\"";
-}
-
-void StateDot::finishNodeLabel(TypePackId tp)
-{
-    if (opts.showPointers)
-        formatAppend(result, "\n0x%p", tp);
-    // additional common attributes can be added here as well
-    result += "\"";
-}
-
-void StateDot::visitChildren(TypeId ty, int index)
-{
-    if (seenTy.count(ty))
-        return;
-    seenTy.insert(ty);
-
-    startNode(index);
-    startNodeLabel();
-
-    if (const BoundTypeVar* btv = get<BoundTypeVar>(ty))
-    {
-        formatAppend(result, "BoundTypeVar %d", index);
-        finishNodeLabel(ty);
-        finishNode();
-
-        visitChild(btv->boundTo, index);
-    }
-    else if (const FunctionTypeVar* ftv = get<FunctionTypeVar>(ty))
-    {
-        formatAppend(result, "FunctionTypeVar %d", index);
-        finishNodeLabel(ty);
-        finishNode();
-
-        visitChild(ftv->argTypes, index, "arg");
-        visitChild(ftv->retType, index, "ret");
-    }
-    else if (const TableTypeVar* ttv = get<TableTypeVar>(ty))
-    {
-        if (ttv->name)
-            formatAppend(result, "TableTypeVar %s", ttv->name->c_str());
-        else if (ttv->syntheticName)
-            formatAppend(result, "TableTypeVar %s", ttv->syntheticName->c_str());
-        else
-            formatAppend(result, "TableTypeVar %d", index);
-        finishNodeLabel(ty);
-        finishNode();
-
-        if (ttv->boundTo)
-            return visitChild(*ttv->boundTo, index, "boundTo");
-
-        for (const auto& [name, prop] : ttv->props)
-            visitChild(prop.type, index, name.c_str());
-        if (ttv->indexer)
-        {
-            visitChild(ttv->indexer->indexType, index, "[index]");
-            visitChild(ttv->indexer->indexResultType, index, "[value]");
-        }
-        for (TypeId itp : ttv->instantiatedTypeParams)
-            visitChild(itp, index, "typeParam");
-
-        if (FFlag::LuauTypeAliasPacks)
-        {
-            for (TypePackId itp : ttv->instantiatedTypePackParams)
-                visitChild(itp, index, "typePackParam");
-        }
-    }
-    else if (const MetatableTypeVar* mtv = get<MetatableTypeVar>(ty))
-    {
-        formatAppend(result, "MetatableTypeVar %d", index);
-        finishNodeLabel(ty);
-        finishNode();
-
-        visitChild(mtv->table, index, "table");
-        visitChild(mtv->metatable, index, "metatable");
-    }
-    else if (const UnionTypeVar* utv = get<UnionTypeVar>(ty))
-    {
-        formatAppend(result, "UnionTypeVar %d", index);
-        finishNodeLabel(ty);
-        finishNode();
-
-        for (TypeId opt : utv->options)
-            visitChild(opt, index);
-    }
-    else if (const IntersectionTypeVar* itv = get<IntersectionTypeVar>(ty))
-    {
-        formatAppend(result, "IntersectionTypeVar %d", index);
-        finishNodeLabel(ty);
-        finishNode();
-
-        for (TypeId part : itv->parts)
-            visitChild(part, index);
-    }
-    else if (const GenericTypeVar* gtv = get<GenericTypeVar>(ty))
-    {
-        if (gtv->explicitName)
-            formatAppend(result, "GenericTypeVar %s", gtv->name.c_str());
-        else
-            formatAppend(result, "GenericTypeVar %d", index);
-        finishNodeLabel(ty);
-        finishNode();
-    }
-    else if (const FreeTypeVar* ftv = get<FreeTypeVar>(ty))
-    {
-        formatAppend(result, "FreeTypeVar %d", ftv->index);
-        finishNodeLabel(ty);
-        finishNode();
-    }
-    else if (get<AnyTypeVar>(ty))
-    {
-        formatAppend(result, "AnyTypeVar %d", index);
-        finishNodeLabel(ty);
-        finishNode();
-    }
-    else if (get<PrimitiveTypeVar>(ty))
-    {
-        formatAppend(result, "PrimitiveTypeVar %s", toStringDetailed(ty, {}).name.c_str());
-        finishNodeLabel(ty);
-        finishNode();
-    }
-    else if (get<ErrorTypeVar>(ty))
-    {
-        formatAppend(result, "ErrorTypeVar %d", index);
-        finishNodeLabel(ty);
-        finishNode();
-    }
-    else if (const ClassTypeVar* ctv = get<ClassTypeVar>(ty))
-    {
-        formatAppend(result, "ClassTypeVar %s", ctv->name.c_str());
-        finishNodeLabel(ty);
-        finishNode();
-
-        for (const auto& [name, prop] : ctv->props)
-            visitChild(prop.type, index, name.c_str());
-
-        if (ctv->parent)
-            visitChild(*ctv->parent, index, "[parent]");
-
-        if (ctv->metatable)
-            visitChild(*ctv->metatable, index, "[metatable]");
-    }
-    else
-    {
-        LUAU_ASSERT(!"unknown type kind");
-        finishNodeLabel(ty);
-        finishNode();
-    }
-}
-
-void StateDot::visitChildren(TypePackId tp, int index)
-{
-    if (seenTp.count(tp))
-        return;
-    seenTp.insert(tp);
-
-    startNode(index);
-    startNodeLabel();
-
-    if (const BoundTypePack* btp = get<BoundTypePack>(tp))
-    {
-        formatAppend(result, "BoundTypePack %d", index);
-        finishNodeLabel(tp);
-        finishNode();
-
-        visitChild(btp->boundTo, index);
-    }
-    else if (const TypePack* tpp = get<TypePack>(tp))
-    {
-        formatAppend(result, "TypePack %d", index);
-        finishNodeLabel(tp);
-        finishNode();
-
-        for (TypeId tv : tpp->head)
-            visitChild(tv, index);
-        if (tpp->tail)
-            visitChild(*tpp->tail, index, "tail");
-    }
-    else if (const VariadicTypePack* vtp = get<VariadicTypePack>(tp))
-    {
-        formatAppend(result, "VariadicTypePack %d", index);
-        finishNodeLabel(tp);
-        finishNode();
-
-        visitChild(vtp->ty, index);
-    }
-    else if (const FreeTypePack* ftp = get<FreeTypePack>(tp))
-    {
-        formatAppend(result, "FreeTypePack %d", ftp->index);
-        finishNodeLabel(tp);
-        finishNode();
-    }
-    else if (const GenericTypePack* gtp = get<GenericTypePack>(tp))
-    {
-        if (gtp->explicitName)
-            formatAppend(result, "GenericTypePack %s", gtp->name.c_str());
-        else
-            formatAppend(result, "GenericTypePack %d", gtp->index);
-        finishNodeLabel(tp);
-        finishNode();
-    }
-    else if (get<Unifiable::Error>(tp))
-    {
-        formatAppend(result, "ErrorTypePack %d", index);
-        finishNodeLabel(tp);
-        finishNode();
-    }
-    else
-    {
-        LUAU_ASSERT(!"unknown type pack kind");
-        finishNodeLabel(tp);
-        finishNode();
-    }
-}
-
-} // namespace
-
-std::string toDot(TypeId ty, const ToDotOptions& opts)
-{
-    StateDot state{opts};
-
-    state.result = "digraph graphname {\n";
-    state.visitChild(ty, 0);
-    state.result += "}";
-
-    return state.result;
-}
-
-std::string toDot(TypePackId tp, const ToDotOptions& opts)
-{
-    StateDot state{opts};
-
-    state.result = "digraph graphname {\n";
-    state.visitChild(tp, 0);
-    state.result += "}";
-
-    return state.result;
-}
-
-std::string toDot(TypeId ty)
-{
-    return toDot(ty, {});
-}
-
-std::string toDot(TypePackId tp)
-{
-    return toDot(tp, {});
-}
-
-void dumpDot(TypeId ty)
-{
-    printf("%s\n", toDot(ty).c_str());
-}
-
-void dumpDot(TypePackId tp)
-{
-    printf("%s\n", toDot(tp).c_str());
-}
-
 const TypeLevel* getLevel(TypeId ty)
 {
     ty = follow(ty);

Analysis/src/Unifier.cpp

@@ -18,9 +18,6 @@ LUAU_FASTFLAGVARIABLE(LuauTableSubtypingVariance, false);
 LUAU_FASTFLAGVARIABLE(LuauUnionHeuristic, false)
 LUAU_FASTFLAGVARIABLE(LuauTableUnificationEarlyTest, false)
 LUAU_FASTFLAGVARIABLE(LuauOccursCheckOkWithRecursiveFunctions, false)
-LUAU_FASTFLAGVARIABLE(LuauTypecheckOpts, false)
-LUAU_FASTFLAG(LuauShareTxnSeen);
-LUAU_FASTFLAGVARIABLE(LuauCacheUnifyTableResults, false)
 LUAU_FASTFLAGVARIABLE(LuauExtendedTypeMismatchError, false)
 LUAU_FASTFLAG(LuauSingletonTypes)
 LUAU_FASTFLAGVARIABLE(LuauExtendedClassMismatchError, false)
@@ -136,38 +133,19 @@ Unifier::Unifier(TypeArena* types, Mode mode, ScopePtr globalScope, const Locati
     , globalScope(std::move(globalScope))
     , location(location)
     , variance(variance)
-    , counters(&countersData)
-    , counters_DEPRECATED(std::make_shared<UnifierCounters>())
-    , sharedState(sharedState)
-{
-    LUAU_ASSERT(sharedState.iceHandler);
-}
-
-Unifier::Unifier(TypeArena* types, Mode mode, ScopePtr globalScope, const std::vector<std::pair<TypeId, TypeId>>& ownedSeen, const Location& location,
-    Variance variance, UnifierSharedState& sharedState, const std::shared_ptr<UnifierCounters>& counters_DEPRECATED, UnifierCounters* counters)
-    : types(types)
-    , mode(mode)
-    , globalScope(std::move(globalScope))
-    , log(ownedSeen)
-    , location(location)
-    , variance(variance)
-    , counters(counters ? counters : &countersData)
-    , counters_DEPRECATED(counters_DEPRECATED ? counters_DEPRECATED : std::make_shared<UnifierCounters>())
     , sharedState(sharedState)
 {
     LUAU_ASSERT(sharedState.iceHandler);
 }
 
 Unifier::Unifier(TypeArena* types, Mode mode, ScopePtr globalScope, std::vector<std::pair<TypeId, TypeId>>* sharedSeen, const Location& location,
-    Variance variance, UnifierSharedState& sharedState, const std::shared_ptr<UnifierCounters>& counters_DEPRECATED, UnifierCounters* counters)
+    Variance variance, UnifierSharedState& sharedState)
     : types(types)
     , mode(mode)
     , globalScope(std::move(globalScope))
     , log(sharedSeen)
     , location(location)
     , variance(variance)
-    , counters(counters ? counters : &countersData)
-    , counters_DEPRECATED(counters_DEPRECATED ? counters_DEPRECATED : std::make_shared<UnifierCounters>())
     , sharedState(sharedState)
 {
     LUAU_ASSERT(sharedState.iceHandler);
@@ -175,26 +153,18 @@ Unifier::Unifier(TypeArena* types, Mode mode, ScopePtr globalScope, std::vector<
 
 void Unifier::tryUnify(TypeId superTy, TypeId subTy, bool isFunctionCall, bool isIntersection)
 {
-    if (FFlag::LuauTypecheckOpts)
+    sharedState.counters.iterationCount = 0;
-        counters->iterationCount = 0;
-    else
-        counters_DEPRECATED->iterationCount = 0;
 
     tryUnify_(superTy, subTy, isFunctionCall, isIntersection);
 }
 
 void Unifier::tryUnify_(TypeId superTy, TypeId subTy, bool isFunctionCall, bool isIntersection)
 {
-    RecursionLimiter _ra(
+    RecursionLimiter _ra(&sharedState.counters.recursionCount, FInt::LuauTypeInferRecursionLimit);
-        FFlag::LuauTypecheckOpts ? &counters->recursionCount : &counters_DEPRECATED->recursionCount, FInt::LuauTypeInferRecursionLimit);
 
-    if (FFlag::LuauTypecheckOpts)
+    ++sharedState.counters.iterationCount;
-        ++counters->iterationCount;
-    else
-        ++counters_DEPRECATED->iterationCount;
 
-    if (FInt::LuauTypeInferIterationLimit > 0 &&
+    if (FInt::LuauTypeInferIterationLimit > 0 && FInt::LuauTypeInferIterationLimit < sharedState.counters.iterationCount)
-        FInt::LuauTypeInferIterationLimit < (FFlag::LuauTypecheckOpts ? counters->iterationCount : counters_DEPRECATED->iterationCount))
     {
         errors.push_back(TypeError{location, UnificationTooComplex{}});
         return;
@@ -302,7 +272,7 @@ void Unifier::tryUnify_(TypeId superTy, TypeId subTy, bool isFunctionCall, bool
     if (get<ErrorTypeVar>(subTy) || get<AnyTypeVar>(subTy))
         return tryUnifyWithAny(subTy, superTy);
 
-    bool cacheEnabled = FFlag::LuauCacheUnifyTableResults && !isFunctionCall && !isIntersection;
+    bool cacheEnabled = !isFunctionCall && !isIntersection;
     auto& cache = sharedState.cachedUnify;
 
     // What if the types are immutable and we proved their relation before
@@ -563,8 +533,6 @@ void Unifier::tryUnify_(TypeId superTy, TypeId subTy, bool isFunctionCall, bool
 
 void Unifier::cacheResult(TypeId superTy, TypeId subTy)
 {
-    LUAU_ASSERT(FFlag::LuauCacheUnifyTableResults);
-
     bool* superTyInfo = sharedState.skipCacheForType.find(superTy);
 
     if (superTyInfo && *superTyInfo)
@@ -686,10 +654,7 @@ ErrorVec Unifier::canUnify(TypePackId superTy, TypePackId subTy, bool isFunction
 
 void Unifier::tryUnify(TypePackId superTp, TypePackId subTp, bool isFunctionCall)
 {
-    if (FFlag::LuauTypecheckOpts)
+    sharedState.counters.iterationCount = 0;
-        counters->iterationCount = 0;
-    else
-        counters_DEPRECATED->iterationCount = 0;
 
     tryUnify_(superTp, subTp, isFunctionCall);
 }
@@ -700,16 +665,11 @@ void Unifier::tryUnify(TypePackId superTp, TypePackId subTp, bool isFunctionCall
  */
 void Unifier::tryUnify_(TypePackId superTp, TypePackId subTp, bool isFunctionCall)
 {
-    RecursionLimiter _ra(
+    RecursionLimiter _ra(&sharedState.counters.recursionCount, FInt::LuauTypeInferRecursionLimit);
-        FFlag::LuauTypecheckOpts ? &counters->recursionCount : &counters_DEPRECATED->recursionCount, FInt::LuauTypeInferRecursionLimit);
 
-    if (FFlag::LuauTypecheckOpts)
+    ++sharedState.counters.iterationCount;
-        ++counters->iterationCount;
-    else
-        ++counters_DEPRECATED->iterationCount;
 
-    if (FInt::LuauTypeInferIterationLimit > 0 &&
+    if (FInt::LuauTypeInferIterationLimit > 0 && FInt::LuauTypeInferIterationLimit < sharedState.counters.iterationCount)
-        FInt::LuauTypeInferIterationLimit < (FFlag::LuauTypecheckOpts ? counters->iterationCount : counters_DEPRECATED->iterationCount))
     {
         errors.push_back(TypeError{location, UnificationTooComplex{}});
         return;
@@ -1727,39 +1687,8 @@ void Unifier::tryUnify(const TableIndexer& superIndexer, const TableIndexer& sub
     tryUnify_(superIndexer.indexResultType, subIndexer.indexResultType);
 }
 
-static void queueTypePack_DEPRECATED(
-    std::vector<TypeId>& queue, std::unordered_set<TypePackId>& seenTypePacks, Unifier& state, TypePackId a, TypePackId anyTypePack)
-{
-    LUAU_ASSERT(!FFlag::LuauTypecheckOpts);
-
-    while (true)
-    {
-        a = follow(a);
-
-        if (seenTypePacks.count(a))
-            break;
-        seenTypePacks.insert(a);
-
-        if (get<Unifiable::Free>(a))
-        {
-            state.log(a);
-            *asMutable(a) = Unifiable::Bound{anyTypePack};
-        }
-        else if (auto tp = get<TypePack>(a))
-        {
-            queue.insert(queue.end(), tp->head.begin(), tp->head.end());
-            if (tp->tail)
-                a = *tp->tail;
-            else
-                break;
-        }
-    }
-}
-
 static void queueTypePack(std::vector<TypeId>& queue, DenseHashSet<TypePackId>& seenTypePacks, Unifier& state, TypePackId a, TypePackId anyTypePack)
 {
-    LUAU_ASSERT(FFlag::LuauTypecheckOpts);
-
     while (true)
     {
         a = follow(a);
@@ -1837,66 +1766,9 @@ void Unifier::tryUnifyVariadics(TypePackId superTp, TypePackId subTp, bool rever
     }
 }
 
-static void tryUnifyWithAny_DEPRECATED(
-    std::vector<TypeId>& queue, Unifier& state, std::unordered_set<TypePackId>& seenTypePacks, TypeId anyType, TypePackId anyTypePack)
-{
-    LUAU_ASSERT(!FFlag::LuauTypecheckOpts);
-
-    std::unordered_set<TypeId> seen;
-
-    while (!queue.empty())
-    {
-        TypeId ty = follow(queue.back());
-        queue.pop_back();
-        if (seen.count(ty))
-            continue;
-        seen.insert(ty);
-
-        if (get<FreeTypeVar>(ty))
-        {
-            state.log(ty);
-            *asMutable(ty) = BoundTypeVar{anyType};
-        }
-        else if (auto fun = get<FunctionTypeVar>(ty))
-        {
-            queueTypePack_DEPRECATED(queue, seenTypePacks, state, fun->argTypes, anyTypePack);
-            queueTypePack_DEPRECATED(queue, seenTypePacks, state, fun->retType, anyTypePack);
-        }
-        else if (auto table = get<TableTypeVar>(ty))
-        {
-            for (const auto& [_name, prop] : table->props)
-                queue.push_back(prop.type);
-
-            if (table->indexer)
-            {
-                queue.push_back(table->indexer->indexType);
-                queue.push_back(table->indexer->indexResultType);
-            }
-        }
-        else if (auto mt = get<MetatableTypeVar>(ty))
-        {
-            queue.push_back(mt->table);
-            queue.push_back(mt->metatable);
-        }
-        else if (get<ClassTypeVar>(ty))
-        {
-            // ClassTypeVars never contain free typevars.
-        }
-        else if (auto union_ = get<UnionTypeVar>(ty))
-            queue.insert(queue.end(), union_->options.begin(), union_->options.end());
-        else if (auto intersection = get<IntersectionTypeVar>(ty))
-            queue.insert(queue.end(), intersection->parts.begin(), intersection->parts.end());
-        else
-        {
-        } // Primitives, any, errors, and generics are left untouched.
-    }
-}
-
 static void tryUnifyWithAny(std::vector<TypeId>& queue, Unifier& state, DenseHashSet<TypeId>& seen, DenseHashSet<TypePackId>& seenTypePacks,
     TypeId anyType, TypePackId anyTypePack)
 {
-    LUAU_ASSERT(FFlag::LuauTypecheckOpts);
-
     while (!queue.empty())
     {
         TypeId ty = follow(queue.back());
@@ -1949,43 +1821,20 @@ void Unifier::tryUnifyWithAny(TypeId any, TypeId ty)
 {
     LUAU_ASSERT(get<AnyTypeVar>(any) || get<ErrorTypeVar>(any));
 
-    if (FFlag::LuauTypecheckOpts)
+    // These types are not visited in general loop below
-    {
+    if (get<PrimitiveTypeVar>(ty) || get<AnyTypeVar>(ty) || get<ClassTypeVar>(ty))
-        // These types are not visited in general loop below
+        return;
-        if (get<PrimitiveTypeVar>(ty) || get<AnyTypeVar>(ty) || get<ClassTypeVar>(ty))
-            return;
-    }
 
     const TypePackId anyTypePack = types->addTypePack(TypePackVar{VariadicTypePack{singletonTypes.anyType}});
 
     const TypePackId anyTP = get<AnyTypeVar>(any) ? anyTypePack : types->addTypePack(TypePackVar{Unifiable::Error{}});
 
-    if (FFlag::LuauTypecheckOpts)
+    std::vector<TypeId> queue = {ty};
-    {
-        std::vector<TypeId> queue = {ty};
 
-        if (FFlag::LuauCacheUnifyTableResults)
+    sharedState.tempSeenTy.clear();
-        {
+    sharedState.tempSeenTp.clear();
-            sharedState.tempSeenTy.clear();
-            sharedState.tempSeenTp.clear();
 
-            Luau::tryUnifyWithAny(queue, *this, sharedState.tempSeenTy, sharedState.tempSeenTp, singletonTypes.anyType, anyTP);
+    Luau::tryUnifyWithAny(queue, *this, sharedState.tempSeenTy, sharedState.tempSeenTp, singletonTypes.anyType, anyTP);
-        }
-        else
-        {
-            tempSeenTy_DEPRECATED.clear();
-            tempSeenTp_DEPRECATED.clear();
-
-            Luau::tryUnifyWithAny(queue, *this, tempSeenTy_DEPRECATED, tempSeenTp_DEPRECATED, singletonTypes.anyType, anyTP);
-        }
-    }
-    else
-    {
-        std::unordered_set<TypePackId> seenTypePacks;
-        std::vector<TypeId> queue = {ty};
-
-        Luau::tryUnifyWithAny_DEPRECATED(queue, *this, seenTypePacks, singletonTypes.anyType, anyTP);
-    }
 }
 
 void Unifier::tryUnifyWithAny(TypePackId any, TypePackId ty)
@@ -1994,38 +1843,14 @@ void Unifier::tryUnifyWithAny(TypePackId any, TypePackId ty)
 
     const TypeId anyTy = singletonTypes.errorRecoveryType();
 
-    if (FFlag::LuauTypecheckOpts)
+    std::vector<TypeId> queue;
-    {
-        std::vector<TypeId> queue;
 
-        if (FFlag::LuauCacheUnifyTableResults)
+    sharedState.tempSeenTy.clear();
-        {
+    sharedState.tempSeenTp.clear();
-            sharedState.tempSeenTy.clear();
-            sharedState.tempSeenTp.clear();
 
-            queueTypePack(queue, sharedState.tempSeenTp, *this, ty, any);
+    queueTypePack(queue, sharedState.tempSeenTp, *this, ty, any);
 
-            Luau::tryUnifyWithAny(queue, *this, sharedState.tempSeenTy, sharedState.tempSeenTp, anyTy, any);
+    Luau::tryUnifyWithAny(queue, *this, sharedState.tempSeenTy, sharedState.tempSeenTp, anyTy, any);
-        }
-        else
-        {
-            tempSeenTy_DEPRECATED.clear();
-            tempSeenTp_DEPRECATED.clear();
-
-            queueTypePack(queue, tempSeenTp_DEPRECATED, *this, ty, any);
-
-            Luau::tryUnifyWithAny(queue, *this, tempSeenTy_DEPRECATED, tempSeenTp_DEPRECATED, anyTy, any);
-        }
-    }
-    else
-    {
-        std::unordered_set<TypePackId> seenTypePacks;
-        std::vector<TypeId> queue;
-
-        queueTypePack_DEPRECATED(queue, seenTypePacks, *this, ty, any);
-
-        Luau::tryUnifyWithAny_DEPRECATED(queue, *this, seenTypePacks, anyTy, any);
-    }
 }
 
 std::optional<TypeId> Unifier::findTablePropertyRespectingMeta(TypeId lhsType, Name name)
@@ -2035,46 +1860,22 @@ std::optional<TypeId> Unifier::findTablePropertyRespectingMeta(TypeId lhsType, N
 
 void Unifier::occursCheck(TypeId needle, TypeId haystack)
 {
-    std::unordered_set<TypeId> seen_DEPRECATED;
+    sharedState.tempSeenTy.clear();
 
-    if (FFlag::LuauCacheUnifyTableResults)
+    return occursCheck(sharedState.tempSeenTy, needle, haystack);
-    {
-        if (FFlag::LuauTypecheckOpts)
-            sharedState.tempSeenTy.clear();
-
-        return occursCheck(seen_DEPRECATED, sharedState.tempSeenTy, needle, haystack);
-    }
-    else
-    {
-        if (FFlag::LuauTypecheckOpts)
-            tempSeenTy_DEPRECATED.clear();
-
-        return occursCheck(seen_DEPRECATED, tempSeenTy_DEPRECATED, needle, haystack);
-    }
 }
 
-void Unifier::occursCheck(std::unordered_set<TypeId>& seen_DEPRECATED, DenseHashSet<TypeId>& seen, TypeId needle, TypeId haystack)
+void Unifier::occursCheck(DenseHashSet<TypeId>& seen, TypeId needle, TypeId haystack)
 {
-    RecursionLimiter _ra(
+    RecursionLimiter _ra(&sharedState.counters.recursionCount, FInt::LuauTypeInferRecursionLimit);
-        FFlag::LuauTypecheckOpts ? &counters->recursionCount : &counters_DEPRECATED->recursionCount, FInt::LuauTypeInferRecursionLimit);
 
     needle = follow(needle);
     haystack = follow(haystack);
 
-    if (FFlag::LuauTypecheckOpts)
+    if (seen.find(haystack))
-    {
+        return;
-        if (seen.find(haystack))
-            return;
 
-        seen.insert(haystack);
+    seen.insert(haystack);
-    }
-    else
-    {
-        if (seen_DEPRECATED.end() != seen_DEPRECATED.find(haystack))
-            return;
-
-        seen_DEPRECATED.insert(haystack);
-    }
 
     if (get<Unifiable::Error>(needle))
         return;
@@ -2091,7 +1892,7 @@ void Unifier::occursCheck(std::unordered_set<TypeId>& seen_DEPRECATED, DenseHash
     }
 
     auto check = [&](TypeId tv) {
-        occursCheck(seen_DEPRECATED, seen, needle, tv);
+        occursCheck(seen, needle, tv);
     };
 
     if (get<FreeTypeVar>(haystack))
@@ -2121,43 +1922,20 @@ void Unifier::occursCheck(std::unordered_set<TypeId>& seen_DEPRECATED, DenseHash
 
 void Unifier::occursCheck(TypePackId needle, TypePackId haystack)
 {
-    std::unordered_set<TypePackId> seen_DEPRECATED;
+    sharedState.tempSeenTp.clear();
 
-    if (FFlag::LuauCacheUnifyTableResults)
+    return occursCheck(sharedState.tempSeenTp, needle, haystack);
-    {
-        if (FFlag::LuauTypecheckOpts)
-            sharedState.tempSeenTp.clear();
-
-        return occursCheck(seen_DEPRECATED, sharedState.tempSeenTp, needle, haystack);
-    }
-    else
-    {
-        if (FFlag::LuauTypecheckOpts)
-            tempSeenTp_DEPRECATED.clear();
-
-        return occursCheck(seen_DEPRECATED, tempSeenTp_DEPRECATED, needle, haystack);
-    }
 }
 
-void Unifier::occursCheck(std::unordered_set<TypePackId>& seen_DEPRECATED, DenseHashSet<TypePackId>& seen, TypePackId needle, TypePackId haystack)
+void Unifier::occursCheck(DenseHashSet<TypePackId>& seen, TypePackId needle, TypePackId haystack)
 {
     needle = follow(needle);
     haystack = follow(haystack);
 
-    if (FFlag::LuauTypecheckOpts)
+    if (seen.find(haystack))
-    {
+        return;
-        if (seen.find(haystack))
-            return;
 
-        seen.insert(haystack);
+    seen.insert(haystack);
-    }
-    else
-    {
-        if (seen_DEPRECATED.end() != seen_DEPRECATED.find(haystack))
-            return;
-
-        seen_DEPRECATED.insert(haystack);
-    }
 
     if (get<Unifiable::Error>(needle))
         return;
@@ -2165,8 +1943,7 @@ void Unifier::occursCheck(std::unordered_set<TypePackId>& seen_DEPRECATED, Dense
     if (!get<Unifiable::Free>(needle))
         ice("Expected needle pack to be free");
 
-    RecursionLimiter _ra(
+    RecursionLimiter _ra(&sharedState.counters.recursionCount, FInt::LuauTypeInferRecursionLimit);
-        FFlag::LuauTypecheckOpts ? &counters->recursionCount : &counters_DEPRECATED->recursionCount, FInt::LuauTypeInferRecursionLimit);
 
     while (!get<ErrorTypeVar>(haystack))
     {
@@ -2186,8 +1963,8 @@ void Unifier::occursCheck(std::unordered_set<TypePackId>& seen_DEPRECATED, Dense
                 {
                     if (auto f = get<FunctionTypeVar>(follow(ty)))
                     {
-                        occursCheck(seen_DEPRECATED, seen, needle, f->argTypes);
+                        occursCheck(seen, needle, f->argTypes);
-                        occursCheck(seen_DEPRECATED, seen, needle, f->retType);
+                        occursCheck(seen, needle, f->retType);
                     }
                 }
             }
@@ -2204,10 +1981,7 @@ void Unifier::occursCheck(std::unordered_set<TypePackId>& seen_DEPRECATED, Dense
 
 Unifier Unifier::makeChildUnifier()
 {
-    if (FFlag::LuauShareTxnSeen)
+    return Unifier{types, mode, globalScope, log.sharedSeen, location, variance, sharedState};
-        return Unifier{types, mode, globalScope, log.sharedSeen, location, variance, sharedState, counters_DEPRECATED, counters};
-    else
-        return Unifier{types, mode, globalScope, log.ownedSeen, location, variance, sharedState, counters_DEPRECATED, counters};
 }
 
 bool Unifier::isNonstrictMode() const

Ast/src/Parser.cpp

@@ -13,8 +13,6 @@ LUAU_FASTINTVARIABLE(LuauParseErrorLimit, 100)
 LUAU_FASTFLAGVARIABLE(LuauCaptureBrokenCommentSpans, false)
 LUAU_FASTFLAGVARIABLE(LuauIfElseExpressionBaseSupport, false)
 LUAU_FASTFLAGVARIABLE(LuauIfStatementRecursionGuard, false)
-LUAU_FASTFLAGVARIABLE(LuauTypeAliasPacks, false)
-LUAU_FASTFLAGVARIABLE(LuauParseTypePackTypeParameters, false)
 LUAU_FASTFLAGVARIABLE(LuauFixAmbiguousErrorRecoveryInAssign, false)
 LUAU_FASTFLAGVARIABLE(LuauParseSingletonTypes, false)
 LUAU_FASTFLAGVARIABLE(LuauParseGenericFunctionTypeBegin, false)
@@ -782,8 +780,7 @@ AstStat* Parser::parseTypeAlias(const Location& start, bool exported)
 
     AstType* type = parseTypeAnnotation();
 
-    return allocator.alloc<AstStatTypeAlias>(
+    return allocator.alloc<AstStatTypeAlias>(Location(start, type->location), name->name, generics, genericPacks, type, exported);
-        Location(start, type->location), name->name, generics, FFlag::LuauTypeAliasPacks ? genericPacks : AstArray<AstName>{}, type, exported);
 }
 
 AstDeclaredClassProp Parser::parseDeclaredClassMethod()
@@ -1602,30 +1599,18 @@ AstTypeOrPack Parser::parseSimpleTypeAnnotation(bool allowPack)
             return {allocator.alloc<AstTypeTypeof>(Location(begin, end), expr), {}};
         }
 
-        if (FFlag::LuauParseTypePackTypeParameters)
+        bool hasParameters = false;
+        AstArray<AstTypeOrPack> parameters{};
+
+        if (lexer.current().type == '<')
         {
-            bool hasParameters = false;
+            hasParameters = true;
-            AstArray<AstTypeOrPack> parameters{};
+            parameters = parseTypeParams();
-
-            if (lexer.current().type == '<')
-            {
-                hasParameters = true;
-                parameters = parseTypeParams();
-            }
-
-            Location end = lexer.previousLocation();
-
-            return {allocator.alloc<AstTypeReference>(Location(begin, end), prefix, name.name, hasParameters, parameters), {}};
         }
-        else
-        {
-            AstArray<AstTypeOrPack> generics = parseTypeParams();
 
-            Location end = lexer.previousLocation();
+        Location end = lexer.previousLocation();
 
-            // false in 'hasParameterList' as it is not used without FFlagLuauTypeAliasPacks
+        return {allocator.alloc<AstTypeReference>(Location(begin, end), prefix, name.name, hasParameters, parameters), {}};
-            return {allocator.alloc<AstTypeReference>(Location(begin, end), prefix, name.name, false, generics), {}};
-        }
     }
     else if (lexer.current().type == '{')
     {
@@ -2414,37 +2399,24 @@ AstArray<AstTypeOrPack> Parser::parseTypeParams()
 
         while (true)
         {
-            if (FFlag::LuauParseTypePackTypeParameters)
+            if (shouldParseTypePackAnnotation(lexer))
             {
-                if (shouldParseTypePackAnnotation(lexer))
+                auto typePack = parseTypePackAnnotation();
-                {
-                    auto typePack = parseTypePackAnnotation();
 
-                    if (FFlag::LuauTypeAliasPacks) // Type packs are recorded only is we can handle them
+                parameters.push_back({{}, typePack});
-                        parameters.push_back({{}, typePack});
+            }
-                }
+            else if (lexer.current().type == '(')
-                else if (lexer.current().type == '(')
+            {
-                {
+                auto [type, typePack] = parseTypeOrPackAnnotation();
-                    auto [type, typePack] = parseTypeOrPackAnnotation();
 
-                    if (typePack)
+                if (typePack)
-                    {
+                    parameters.push_back({{}, typePack});
-                        if (FFlag::LuauTypeAliasPacks) // Type packs are recorded only is we can handle them
-                            parameters.push_back({{}, typePack});
-                    }
-                    else
-                    {
-                        parameters.push_back({type, {}});
-                    }
-                }
-                else if (lexer.current().type == '>' && parameters.empty())
-                {
-                    break;
-                }
                 else
-                {
+                    parameters.push_back({type, {}});
-                    parameters.push_back({parseTypeAnnotation(), {}});
+            }
-                }
+            else if (lexer.current().type == '>' && parameters.empty())
+            {
+                break;
             }
             else
             {

CLI/Analyze.cpp

@@ -121,7 +121,7 @@ struct CliFileResolver : Luau::FileResolver
         if (Luau::AstExprConstantString* expr = node->as<Luau::AstExprConstantString>())
         {
             Luau::ModuleName name = std::string(expr->value.data, expr->value.size) + ".luau";
-            if (!moduleExists(name))
+            if (!readFile(name))
             {
                 // fall back to .lua if a module with .luau doesn't exist
                 name = std::string(expr->value.data, expr->value.size) + ".lua";
@@ -132,27 +132,6 @@ struct CliFileResolver : Luau::FileResolver
 
         return std::nullopt;
     }
-
-    bool moduleExists(const Luau::ModuleName& name) const override
-    {
-        return !!readFile(name);
-    }
-
-
-    std::optional<Luau::ModuleName> fromAstFragment(Luau::AstExpr* expr) const override
-    {
-        return std::nullopt;
-    }
-
-    Luau::ModuleName concat(const Luau::ModuleName& lhs, std::string_view rhs) const override
-    {
-        return lhs + "/" + std::string(rhs);
-    }
-
-    std::optional<Luau::ModuleName> getParentModuleName(const Luau::ModuleName& name) const override
-    {
-        return std::nullopt;
-    }
 };
 
 struct CliConfigResolver : Luau::ConfigResolver

CLI/Repl.cpp

@@ -198,11 +198,6 @@ static std::string runCode(lua_State* L, const std::string& source)
         error += "\nstack backtrace:\n";
         error += lua_debugtrace(T);
 
-#ifdef __EMSCRIPTEN__
-        // nicer formatting for errors in web repl
-        error = "Error:" + error;
-#endif
-
         fprintf(stdout, "%s", error.c_str());
     }
 
@@ -210,39 +205,6 @@ static std::string runCode(lua_State* L, const std::string& source)
     return std::string();
 }
 
-#ifdef __EMSCRIPTEN__
-extern "C"
-{
-    const char* executeScript(const char* source)
-    {
-        // setup flags
-        for (Luau::FValue<bool>* flag = Luau::FValue<bool>::list; flag; flag = flag->next)
-            if (strncmp(flag->name, "Luau", 4) == 0)
-                flag->value = true;
-
-        // create new state
-        std::unique_ptr<lua_State, void (*)(lua_State*)> globalState(luaL_newstate(), lua_close);
-        lua_State* L = globalState.get();
-
-        // setup state
-        setupState(L);
-
-        // sandbox thread
-        luaL_sandboxthread(L);
-
-        // static string for caching result (prevents dangling ptr on function exit)
-        static std::string result;
-
-        // run code + collect error
-        result = runCode(L, source);
-
-        return result.empty() ? NULL : result.c_str();
-    }
-}
-#endif
-
-// Excluded from emscripten compilation to avoid -Wunused-function errors.
-#ifndef __EMSCRIPTEN__
 static void completeIndexer(lua_State* L, const char* editBuffer, size_t start, std::vector<std::string>& completions)
 {
     std::string_view lookup = editBuffer + start;
@@ -564,6 +526,5 @@ int main(int argc, char** argv)
         return failed;
     }
 }
-#endif
 
 

CLI/Web.cpp

@@ -0,0 +1,106 @@
+// This file is part of the Luau programming language and is licensed under MIT License; see LICENSE.txt for details
+#include "lua.h"
+#include "lualib.h"
+#include "luacode.h"
+
+#include "Luau/Common.h"
+
+#include <string>
+
+#include <string.h>
+
+static void setupState(lua_State* L)
+{
+    luaL_openlibs(L);
+
+    luaL_sandbox(L);
+}
+
+static std::string runCode(lua_State* L, const std::string& source)
+{
+    size_t bytecodeSize = 0;
+    char* bytecode = luau_compile(source.data(), source.length(), nullptr, &bytecodeSize);
+    int result = luau_load(L, "=stdin", bytecode, bytecodeSize, 0);
+    free(bytecode);
+
+    if (result != 0)
+    {
+        size_t len;
+        const char* msg = lua_tolstring(L, -1, &len);
+
+        std::string error(msg, len);
+        lua_pop(L, 1);
+
+        return error;
+    }
+
+    lua_State* T = lua_newthread(L);
+
+    lua_pushvalue(L, -2);
+    lua_remove(L, -3);
+    lua_xmove(L, T, 1);
+
+    int status = lua_resume(T, NULL, 0);
+
+    if (status == 0)
+    {
+        int n = lua_gettop(T);
+
+        if (n)
+        {
+            luaL_checkstack(T, LUA_MINSTACK, "too many results to print");
+            lua_getglobal(T, "print");
+            lua_insert(T, 1);
+            lua_pcall(T, n, 0, 0);
+        }
+    }
+    else
+    {
+        std::string error;
+
+        if (status == LUA_YIELD)
+        {
+            error = "thread yielded unexpectedly";
+        }
+        else if (const char* str = lua_tostring(T, -1))
+        {
+            error = str;
+        }
+
+        error += "\nstack backtrace:\n";
+        error += lua_debugtrace(T);
+
+        error = "Error:" + error;
+
+        fprintf(stdout, "%s", error.c_str());
+    }
+
+    lua_pop(L, 1);
+    return std::string();
+}
+
+extern "C" const char* executeScript(const char* source)
+{
+    // setup flags
+    for (Luau::FValue<bool>* flag = Luau::FValue<bool>::list; flag; flag = flag->next)
+        if (strncmp(flag->name, "Luau", 4) == 0)
+            flag->value = true;
+
+    // create new state
+    std::unique_ptr<lua_State, void (*)(lua_State*)> globalState(luaL_newstate(), lua_close);
+    lua_State* L = globalState.get();
+
+    // setup state
+    setupState(L);
+
+    // sandbox thread
+    luaL_sandboxthread(L);
+
+    // static string for caching result (prevents dangling ptr on function exit)
+    static std::string result;
+
+    // run code + collect error
+    result = runCode(L, source);
+
+    return result.empty() ? NULL : result.c_str();
+}

CMakeLists.txt

@@ -9,6 +9,7 @@ project(Luau LANGUAGES CXX)
 
 option(LUAU_BUILD_CLI "Build CLI" ON)
 option(LUAU_BUILD_TESTS "Build tests" ON)
+option(LUAU_BUILD_WEB "Build Web module" OFF)
 option(LUAU_WERROR "Warnings as errors" OFF)
 
 add_library(Luau.Ast STATIC)
@@ -18,26 +19,22 @@ add_library(Luau.VM STATIC)
 
 if(LUAU_BUILD_CLI)
     add_executable(Luau.Repl.CLI)
-    if(NOT EMSCRIPTEN)
+    add_executable(Luau.Analyze.CLI)
-        add_executable(Luau.Analyze.CLI)
-    else()
-        # add -fexceptions for emscripten to allow exceptions to be caught in C++
-        set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fexceptions")
-    endif()
 
     # This also adds target `name` on Linux/macOS and `name.exe` on Windows
     set_target_properties(Luau.Repl.CLI PROPERTIES OUTPUT_NAME luau)
-
+    set_target_properties(Luau.Analyze.CLI PROPERTIES OUTPUT_NAME luau-analyze)
-    if(NOT EMSCRIPTEN)
-        set_target_properties(Luau.Analyze.CLI PROPERTIES OUTPUT_NAME luau-analyze)
-    endif()
 endif()
 
-if(LUAU_BUILD_TESTS AND NOT EMSCRIPTEN)
+if(LUAU_BUILD_TESTS)
     add_executable(Luau.UnitTest)
     add_executable(Luau.Conformance)
 endif()
 
+if(LUAU_BUILD_WEB)
+    add_executable(Luau.Web)
+endif()
+
 include(Sources.cmake)
 
 target_compile_features(Luau.Ast PUBLIC cxx_std_17)
@@ -72,16 +69,18 @@ if(LUAU_WERROR)
     endif()
 endif()
 
+if(LUAU_BUILD_WEB)
+    # add -fexceptions for emscripten to allow exceptions to be caught in C++
+    list(APPEND LUAU_OPTIONS -fexceptions)
+endif()
+
 target_compile_options(Luau.Ast PRIVATE ${LUAU_OPTIONS})
 target_compile_options(Luau.Analysis PRIVATE ${LUAU_OPTIONS})
 target_compile_options(Luau.VM PRIVATE ${LUAU_OPTIONS})
 
 if(LUAU_BUILD_CLI)
     target_compile_options(Luau.Repl.CLI PRIVATE ${LUAU_OPTIONS})
-
+    target_compile_options(Luau.Analyze.CLI PRIVATE ${LUAU_OPTIONS})
-    if(NOT EMSCRIPTEN)
-        target_compile_options(Luau.Analyze.CLI PRIVATE ${LUAU_OPTIONS})
-    endif()
 
     target_include_directories(Luau.Repl.CLI PRIVATE extern)
     target_link_libraries(Luau.Repl.CLI PRIVATE Luau.Compiler Luau.VM)
@@ -93,20 +92,10 @@ if(LUAU_BUILD_CLI)
         endif()
     endif()
 
-    if(NOT EMSCRIPTEN)
+    target_link_libraries(Luau.Analyze.CLI PRIVATE Luau.Analysis)
-        target_link_libraries(Luau.Analyze.CLI PRIVATE Luau.Analysis)
-    endif()
-
-    if(EMSCRIPTEN)
-        # declare exported functions to emscripten
-        target_link_options(Luau.Repl.CLI PRIVATE -sEXPORTED_FUNCTIONS=['_executeScript'] -sEXPORTED_RUNTIME_METHODS=['ccall','cwrap'] -fexceptions)
-
-        # custom output directory for wasm + js file
-        set_target_properties(Luau.Repl.CLI PROPERTIES RUNTIME_OUTPUT_DIRECTORY ${CMAKE_SOURCE_DIR}/docs/assets/luau)
-    endif()
 endif()
 
-if(LUAU_BUILD_TESTS AND NOT EMSCRIPTEN)
+if(LUAU_BUILD_TESTS)
     target_compile_options(Luau.UnitTest PRIVATE ${LUAU_OPTIONS})
     target_include_directories(Luau.UnitTest PRIVATE extern)
     target_link_libraries(Luau.UnitTest PRIVATE Luau.Analysis Luau.Compiler)
@@ -115,3 +104,17 @@ if(LUAU_BUILD_TESTS AND NOT EMSCRIPTEN)
     target_include_directories(Luau.Conformance PRIVATE extern)
     target_link_libraries(Luau.Conformance PRIVATE Luau.Analysis Luau.Compiler Luau.VM)
 endif()
+
+if(LUAU_BUILD_WEB)
+    target_compile_options(Luau.Web PRIVATE ${LUAU_OPTIONS})
+    target_link_libraries(Luau.Web PRIVATE Luau.Compiler Luau.VM)
+
+    # declare exported functions to emscripten
+    target_link_options(Luau.Web PRIVATE -sEXPORTED_FUNCTIONS=['_executeScript'] -sEXPORTED_RUNTIME_METHODS=['ccall','cwrap'])
+
+    # add -fexceptions for emscripten to allow exceptions to be caught in C++
+    target_link_options(Luau.Web PRIVATE -fexceptions)
+
+    # the output is a single .js file with an embedded wasm blob
+    target_link_options(Luau.Web PRIVATE -sSINGLE_FILE=1)
+endif()

Compiler/src/Compiler.cpp

@@ -321,13 +321,15 @@ struct Compiler
                     compileExprTempTop(expr->args.data[i], uint8_t(regs + 1 + expr->self + i));
         }
 
-        setDebugLine(expr->func);
+        setDebugLineEnd(expr->func);
 
         if (expr->self)
         {
             AstExprIndexName* fi = expr->func->as<AstExprIndexName>();
             LUAU_ASSERT(fi);
 
+            setDebugLine(fi->indexLocation);
+
             BytecodeBuilder::StringRef iname = sref(fi->index);
             int32_t cid = bytecode.addConstantString(iname);
             if (cid < 0)
@@ -1313,6 +1315,8 @@ struct Compiler
         RegScope rs(this);
         uint8_t reg = compileExprAuto(expr->expr, rs);
 
+        setDebugLine(expr->indexLocation);
+
         BytecodeBuilder::StringRef iname = sref(expr->index);
         int32_t cid = bytecode.addConstantString(iname);
         if (cid < 0)
@@ -2710,6 +2714,12 @@ struct Compiler
             bytecode.setDebugLine(node->location.begin.line + 1);
     }
 
+    void setDebugLine(const Location& location)
+    {
+        if (options.debugLevel >= 1)
+            bytecode.setDebugLine(location.begin.line + 1);
+    }
+
     void setDebugLineEnd(AstNode* node)
     {
         if (options.debugLevel >= 1)
@@ -3650,7 +3660,7 @@ struct Compiler
         {
             if (options.vectorLib)
             {
-                if (builtin.object == options.vectorLib && builtin.method == options.vectorCtor)
+                if (builtin.isMethod(options.vectorLib, options.vectorCtor))
                     return LBF_VECTOR;
             }
             else

Makefile

@@ -35,7 +35,7 @@ ANALYZE_CLI_SOURCES=CLI/FileUtils.cpp CLI/Analyze.cpp
 ANALYZE_CLI_OBJECTS=$(ANALYZE_CLI_SOURCES:%=$(BUILD)/%.o)
 ANALYZE_CLI_TARGET=$(BUILD)/luau-analyze
 
-FUZZ_SOURCES=$(wildcard fuzz/*.cpp)
+FUZZ_SOURCES=$(wildcard fuzz/*.cpp) fuzz/luau.pb.cpp
 FUZZ_OBJECTS=$(FUZZ_SOURCES:%=$(BUILD)/%.o)
 
 TESTS_ARGS=
@@ -167,8 +167,8 @@ fuzz/luau.pb.cpp: fuzz/luau.proto build/libprotobuf-mutator
 	cd fuzz && ../build/libprotobuf-mutator/external.protobuf/bin/protoc luau.proto --cpp_out=.
 	mv fuzz/luau.pb.cc fuzz/luau.pb.cpp
 
-$(BUILD)/fuzz/proto.cpp.o: build/libprotobuf-mutator
+$(BUILD)/fuzz/proto.cpp.o: fuzz/luau.pb.cpp
-$(BUILD)/fuzz/protoprint.cpp.o: build/libprotobuf-mutator
+$(BUILD)/fuzz/protoprint.cpp.o: fuzz/luau.pb.cpp
 
 build/libprotobuf-mutator:
 	git clone https://github.com/google/libprotobuf-mutator build/libprotobuf-mutator

Sources.cmake

@@ -54,6 +54,7 @@ target_sources(Luau.Analysis PRIVATE
     Analysis/include/Luau/Scope.h
     Analysis/include/Luau/Substitution.h
     Analysis/include/Luau/Symbol.h
+    Analysis/include/Luau/ToDot.h
     Analysis/include/Luau/TopoSortStatements.h
     Analysis/include/Luau/ToString.h
     Analysis/include/Luau/Transpiler.h
@@ -86,6 +87,7 @@ target_sources(Luau.Analysis PRIVATE
     Analysis/src/Scope.cpp
     Analysis/src/Substitution.cpp
     Analysis/src/Symbol.cpp
+    Analysis/src/ToDot.cpp
     Analysis/src/TopoSortStatements.cpp
     Analysis/src/ToString.cpp
     Analysis/src/Transpiler.cpp
@@ -118,6 +120,7 @@ target_sources(Luau.VM PRIVATE
     VM/src/ldo.cpp
     VM/src/lfunc.cpp
     VM/src/lgc.cpp
+    VM/src/lgcdebug.cpp
     VM/src/linit.cpp
     VM/src/lmathlib.cpp
     VM/src/lmem.cpp
@@ -194,6 +197,7 @@ if(TARGET Luau.UnitTest)
         tests/RequireTracer.test.cpp
         tests/StringUtils.test.cpp
         tests/Symbol.test.cpp
+        tests/ToDot.test.cpp
         tests/TopoSort.test.cpp
         tests/ToString.test.cpp
         tests/Transpiler.test.cpp
@@ -224,3 +228,9 @@ if(TARGET Luau.Conformance)
         tests/Conformance.test.cpp
         tests/main.cpp)
 endif()
+
+if(TARGET Luau.Web)
+    # Luau.Web Sources
+    target_sources(Luau.Web PRIVATE
+        CLI/Web.cpp)
+endif()

VM/include/lua.h

@@ -21,6 +21,7 @@
 #define LUA_ENVIRONINDEX (-10001)
 #define LUA_GLOBALSINDEX (-10002)
 #define lua_upvalueindex(i) (LUA_GLOBALSINDEX - (i))
+#define lua_ispseudo(i) ((i) <= LUA_REGISTRYINDEX)
 
 /* thread status; 0 is OK */
 enum lua_Status
@@ -108,6 +109,7 @@ LUA_API int lua_isthreadreset(lua_State* L);
 /*
 ** basic stack manipulation
 */
+LUA_API int lua_absindex(lua_State* L, int idx);
 LUA_API int lua_gettop(lua_State* L);
 LUA_API void lua_settop(lua_State* L, int idx);
 LUA_API void lua_pushvalue(lua_State* L, int idx);
@@ -159,7 +161,11 @@ LUA_API void lua_pushnil(lua_State* L);
 LUA_API void lua_pushnumber(lua_State* L, double n);
 LUA_API void lua_pushinteger(lua_State* L, int n);
 LUA_API void lua_pushunsigned(lua_State* L, unsigned n);
+#if LUA_VECTOR_SIZE == 4
+LUA_API void lua_pushvector(lua_State* L, float x, float y, float z, float w);
+#else
 LUA_API void lua_pushvector(lua_State* L, float x, float y, float z);
+#endif
 LUA_API void lua_pushlstring(lua_State* L, const char* s, size_t l);
 LUA_API void lua_pushstring(lua_State* L, const char* s);
 LUA_API const char* lua_pushvfstring(lua_State* L, const char* fmt, va_list argp);
@@ -183,7 +189,7 @@ LUA_API void lua_setreadonly(lua_State* L, int idx, int enabled);
 LUA_API int lua_getreadonly(lua_State* L, int idx);
 LUA_API void lua_setsafeenv(lua_State* L, int idx, int enabled);
 
-LUA_API void* lua_newuserdata(lua_State* L, size_t sz, int tag);
+LUA_API void* lua_newuserdatatagged(lua_State* L, size_t sz, int tag);
 LUA_API void* lua_newuserdatadtor(lua_State* L, size_t sz, void (*dtor)(void*));
 LUA_API int lua_getmetatable(lua_State* L, int objindex);
 LUA_API void lua_getfenv(lua_State* L, int idx);
@@ -227,6 +233,7 @@ enum lua_GCOp
     LUA_GCRESTART,
     LUA_GCCOLLECT,
     LUA_GCCOUNT,
+    LUA_GCCOUNTB,
     LUA_GCISRUNNING,
 
     // garbage collection is handled by 'assists' that perform some amount of GC work matching pace of allocation
@@ -281,6 +288,7 @@ LUA_API void lua_unref(lua_State* L, int ref);
 #define lua_pop(L, n) lua_settop(L, -(n)-1)
 
 #define lua_newtable(L) lua_createtable(L, 0, 0)
+#define lua_newuserdata(L, s) lua_newuserdatatagged(L, s, 0)
 
 #define lua_strlen(L, i) lua_objlen(L, (i))
 
@@ -289,6 +297,7 @@ LUA_API void lua_unref(lua_State* L, int ref);
 #define lua_islightuserdata(L, n) (lua_type(L, (n)) == LUA_TLIGHTUSERDATA)
 #define lua_isnil(L, n) (lua_type(L, (n)) == LUA_TNIL)
 #define lua_isboolean(L, n) (lua_type(L, (n)) == LUA_TBOOLEAN)
+#define lua_isvector(L, n) (lua_type(L, (n)) == LUA_TVECTOR)
 #define lua_isthread(L, n) (lua_type(L, (n)) == LUA_TTHREAD)
 #define lua_isnone(L, n) (lua_type(L, (n)) == LUA_TNONE)
 #define lua_isnoneornil(L, n) (lua_type(L, (n)) <= LUA_TNIL)

VM/include/luaconf.h

@@ -34,7 +34,10 @@
 #endif
 
 /* 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 */
@@ -47,10 +50,14 @@
 #endif
 
 /* 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 */
+#ifndef LUA_IDSIZE
 #define LUA_IDSIZE 256
+#endif
 
 /*
 @@ LUAI_GCGOAL defines the desired top heap size in relation to the live heap
@@ -59,7 +66,9 @@
 ** mean larger GC pauses which mean slower collection.) You can also change
 ** this value dynamically.
 */
+#ifndef LUAI_GCGOAL
 #define LUAI_GCGOAL 200 /* 200% (allow heap to double compared to live heap size) */
+#endif
 
 /*
 @@ LUAI_GCSTEPMUL / LUAI_GCSTEPSIZE define the default speed of garbage collection
@@ -69,38 +78,63 @@
 ** CHANGE it if you want to change the granularity of the garbage
 ** collection.
 */
+#ifndef LUAI_GCSTEPMUL
 #define LUAI_GCSTEPMUL 200 /* GC runs 'twice the speed' of memory allocation */
+#endif
+
+#ifndef LUAI_GCSTEPSIZE
 #define LUAI_GCSTEPSIZE 1  /* GC runs every KB of memory allocation */
+#endif
 
 /* 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 */
+#ifndef LUAI_MAXCSTACK
 #define LUAI_MAXCSTACK 8000
+#endif
 
 /* 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 */
+#ifndef LUAI_MAXCCALLS
 #define LUAI_MAXCCALLS 200
+#endif
 
 /* 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 */
+#ifndef LUA_UTAG_LIMIT
 #define LUA_UTAG_LIMIT 128
+#endif
 
 /* 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 */
+#ifndef LUA_MEMORY_CATEGORIES
 #define LUA_MEMORY_CATEGORIES 256
+#endif
 
 /* 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 */
+#ifndef LUA_MAXCAPTURES
 #define LUA_MAXCAPTURES 32
+#endif
 
 /* }================================================================== */
 
@@ -122,3 +156,7 @@
         void* s; \
         long l; \
     }
+
+#define LUA_VECTOR_SIZE 3	/* must be 3 or 4 */
+
+#define LUA_EXTRA_SIZE LUA_VECTOR_SIZE - 2

VM/include/lualib.h

@@ -25,11 +25,17 @@ LUALIB_API const char* luaL_optlstring(lua_State* L, int numArg, const char* def
 LUALIB_API double luaL_checknumber(lua_State* L, int numArg);
 LUALIB_API double luaL_optnumber(lua_State* L, int nArg, double def);
 
+LUALIB_API int luaL_checkboolean(lua_State* L, int narg);
+LUALIB_API int luaL_optboolean(lua_State* L, int narg, int def);
+
 LUALIB_API int luaL_checkinteger(lua_State* L, int numArg);
 LUALIB_API int luaL_optinteger(lua_State* L, int nArg, int def);
 LUALIB_API unsigned luaL_checkunsigned(lua_State* L, int numArg);
 LUALIB_API unsigned luaL_optunsigned(lua_State* L, int numArg, unsigned def);
 
+LUALIB_API const float* luaL_checkvector(lua_State* L, int narg);
+LUALIB_API const float* luaL_optvector(lua_State* L, int narg, const float* def);
+
 LUALIB_API void luaL_checkstack(lua_State* L, int sz, const char* msg);
 LUALIB_API void luaL_checktype(lua_State* L, int narg, int t);
 LUALIB_API void luaL_checkany(lua_State* L, int narg);

VM/src/lapi.cpp

@@ -13,6 +13,8 @@
 
 #include <string.h>
 
+LUAU_FASTFLAG(LuauActivateBeforeExec)
+
 const char* lua_ident = "$Lua: Lua 5.1.4 Copyright (C) 1994-2008 Lua.org, PUC-Rio $\n"
                         "$Authors: R. Ierusalimschy, L. H. de Figueiredo & W. Celes $\n"
                         "$URL: www.lua.org $\n";
@@ -170,6 +172,12 @@ lua_State* lua_mainthread(lua_State* L)
 ** basic stack manipulation
 */
 
+int lua_absindex(lua_State* L, int idx)
+{
+    api_check(L, (idx > 0 && idx <= L->top - L->base) || (idx < 0 && -idx <= L->top - L->base) || lua_ispseudo(idx));
+    return idx > 0 || lua_ispseudo(idx) ? idx : cast_int(L->top - L->base) + idx + 1;
+}
+
 int lua_gettop(lua_State* L)
 {
     return cast_int(L->top - L->base);
@@ -550,12 +558,21 @@ void lua_pushunsigned(lua_State* L, unsigned u)
     return;
 }
 
-void lua_pushvector(lua_State* L, float x, float y, float z)
+#if LUA_VECTOR_SIZE == 4
+void lua_pushvector(lua_State* L, float x, float y, float z, float w)
 {
-    setvvalue(L->top, x, y, z);
+    setvvalue(L->top, x, y, z, w);
     api_incr_top(L);
     return;
 }
+#else
+void lua_pushvector(lua_State* L, float x, float y, float z)
+{
+    setvvalue(L->top, x, y, z, 0.0f);
+    api_incr_top(L);
+    return;
+}
+#endif
 
 void lua_pushlstring(lua_State* L, const char* s, size_t len)
 {
@@ -922,14 +939,21 @@ void lua_call(lua_State* L, int nargs, int nresults)
     checkresults(L, nargs, nresults);
     func = L->top - (nargs + 1);
 
-    int wasActive = luaC_threadactive(L);
+    if (FFlag::LuauActivateBeforeExec)
-    l_setbit(L->stackstate, THREAD_ACTIVEBIT);
+    {
-    luaC_checkthreadsleep(L);
+        luaD_call(L, func, nresults);
+    }
+    else
+    {
+        int oldactive = luaC_threadactive(L);
+        l_setbit(L->stackstate, THREAD_ACTIVEBIT);
+        luaC_checkthreadsleep(L);
 
-    luaD_call(L, func, nresults);
+        luaD_call(L, func, nresults);
 
-    if (!wasActive)
+        if (!oldactive)
-        resetbit(L->stackstate, THREAD_ACTIVEBIT);
+            resetbit(L->stackstate, THREAD_ACTIVEBIT);
+    }
 
     adjustresults(L, nresults);
     return;
@@ -970,14 +994,21 @@ int lua_pcall(lua_State* L, int nargs, int nresults, int errfunc)
     c.func = L->top - (nargs + 1); /* function to be called */
     c.nresults = nresults;
 
-    int wasActive = luaC_threadactive(L);
+    if (FFlag::LuauActivateBeforeExec)
-    l_setbit(L->stackstate, THREAD_ACTIVEBIT);
+    {
-    luaC_checkthreadsleep(L);
+        status = luaD_pcall(L, f_call, &c, savestack(L, c.func), func);
+    }
+    else
+    {
+        int oldactive = luaC_threadactive(L);
+        l_setbit(L->stackstate, THREAD_ACTIVEBIT);
+        luaC_checkthreadsleep(L);
 
-    status = luaD_pcall(L, f_call, &c, savestack(L, c.func), func);
+        status = luaD_pcall(L, f_call, &c, savestack(L, c.func), func);
 
-    if (!wasActive)
+        if (!oldactive)
-        resetbit(L->stackstate, THREAD_ACTIVEBIT);
+            resetbit(L->stackstate, THREAD_ACTIVEBIT);
+    }
 
     adjustresults(L, nresults);
     return status;
@@ -1030,6 +1061,11 @@ int lua_gc(lua_State* L, int what, int data)
         res = cast_int(g->totalbytes >> 10);
         break;
     }
+    case LUA_GCCOUNTB:
+    {
+        res = cast_int(g->totalbytes & 1023);
+        break;
+    }
     case LUA_GCISRUNNING:
     {
         res = (g->GCthreshold != SIZE_MAX);
@@ -1146,7 +1182,7 @@ void lua_concat(lua_State* L, int n)
     return;
 }
 
-void* lua_newuserdata(lua_State* L, size_t sz, int tag)
+void* lua_newuserdatatagged(lua_State* L, size_t sz, int tag)
 {
     api_check(L, unsigned(tag) < LUA_UTAG_LIMIT);
     luaC_checkGC(L);
@@ -1231,6 +1267,7 @@ 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 */
     int ref = LUA_REFNIL;
     global_State* g = L->global;
     StkId p = index2adr(L, idx);

VM/src/laux.cpp

@@ -30,7 +30,7 @@ static const char* currfuncname(lua_State* L)
         return debugname;
 }
 
-LUALIB_API l_noret luaL_argerrorL(lua_State* L, int narg, const char* extramsg)
+l_noret luaL_argerrorL(lua_State* L, int narg, const char* extramsg)
 {
     const char* fname = currfuncname(L);
 
@@ -40,7 +40,7 @@ LUALIB_API l_noret luaL_argerrorL(lua_State* L, int narg, const char* extramsg)
         luaL_error(L, "invalid argument #%d (%s)", narg, extramsg);
 }
 
-LUALIB_API l_noret luaL_typeerrorL(lua_State* L, int narg, const char* tname)
+l_noret luaL_typeerrorL(lua_State* L, int narg, const char* tname)
 {
     const char* fname = currfuncname(L);
     const TValue* obj = luaA_toobject(L, narg);
@@ -66,7 +66,7 @@ static l_noret tag_error(lua_State* L, int narg, int tag)
     luaL_typeerrorL(L, narg, lua_typename(L, tag));
 }
 
-LUALIB_API void luaL_where(lua_State* L, int level)
+void luaL_where(lua_State* L, int level)
 {
     lua_Debug ar;
     if (lua_getinfo(L, level, "sl", &ar) && ar.currentline > 0)
@@ -77,7 +77,7 @@ LUALIB_API void luaL_where(lua_State* L, int level)
     lua_pushliteral(L, ""); /* else, no information available... */
 }
 
-LUALIB_API l_noret luaL_errorL(lua_State* L, const char* fmt, ...)
+l_noret luaL_errorL(lua_State* L, const char* fmt, ...)
 {
     va_list argp;
     va_start(argp, fmt);
@@ -90,7 +90,7 @@ LUALIB_API l_noret luaL_errorL(lua_State* L, const char* fmt, ...)
 
 /* }====================================================== */
 
-LUALIB_API int luaL_checkoption(lua_State* L, int narg, const char* def, const char* const lst[])
+int luaL_checkoption(lua_State* L, int narg, const char* def, const char* const lst[])
 {
     const char* name = (def) ? luaL_optstring(L, narg, def) : luaL_checkstring(L, narg);
     int i;
@@ -101,7 +101,7 @@ LUALIB_API int luaL_checkoption(lua_State* L, int narg, const char* def, const c
     luaL_argerrorL(L, narg, msg);
 }
 
-LUALIB_API int luaL_newmetatable(lua_State* L, const char* tname)
+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? */
@@ -113,7 +113,7 @@ LUALIB_API int luaL_newmetatable(lua_State* L, const char* tname)
     return 1;
 }
 
-LUALIB_API void* luaL_checkudata(lua_State* L, int ud, const char* tname)
+void* luaL_checkudata(lua_State* L, int ud, const char* tname)
 {
     void* p = lua_touserdata(L, ud);
     if (p != NULL)
@@ -131,25 +131,25 @@ LUALIB_API void* luaL_checkudata(lua_State* L, int ud, const char* tname)
     luaL_typeerrorL(L, ud, tname); /* else error */
 }
 
-LUALIB_API void luaL_checkstack(lua_State* L, int space, const char* mes)
+void luaL_checkstack(lua_State* L, int space, const char* mes)
 {
     if (!lua_checkstack(L, space))
         luaL_error(L, "stack overflow (%s)", mes);
 }
 
-LUALIB_API void luaL_checktype(lua_State* L, int narg, int t)
+void luaL_checktype(lua_State* L, int narg, int t)
 {
     if (lua_type(L, narg) != t)
         tag_error(L, narg, t);
 }
 
-LUALIB_API void luaL_checkany(lua_State* L, int narg)
+void luaL_checkany(lua_State* L, int narg)
 {
     if (lua_type(L, narg) == LUA_TNONE)
         luaL_error(L, "missing argument #%d", narg);
 }
 
-LUALIB_API const char* luaL_checklstring(lua_State* L, int narg, size_t* len)
+const char* luaL_checklstring(lua_State* L, int narg, size_t* len)
 {
     const char* s = lua_tolstring(L, narg, len);
     if (!s)
@@ -157,7 +157,7 @@ LUALIB_API const char* luaL_checklstring(lua_State* L, int narg, size_t* len)
     return s;
 }
 
-LUALIB_API const char* luaL_optlstring(lua_State* L, int narg, const char* def, size_t* len)
+const char* luaL_optlstring(lua_State* L, int narg, const char* def, size_t* len)
 {
     if (lua_isnoneornil(L, narg))
     {
@@ -169,7 +169,7 @@ LUALIB_API const char* luaL_optlstring(lua_State* L, int narg, const char* def,
         return luaL_checklstring(L, narg, len);
 }
 
-LUALIB_API double luaL_checknumber(lua_State* L, int narg)
+double luaL_checknumber(lua_State* L, int narg)
 {
     int isnum;
     double d = lua_tonumberx(L, narg, &isnum);
@@ -178,12 +178,28 @@ LUALIB_API double luaL_checknumber(lua_State* L, int narg)
     return d;
 }
 
-LUALIB_API double luaL_optnumber(lua_State* L, int narg, double def)
+double luaL_optnumber(lua_State* L, int narg, double def)
 {
     return luaL_opt(L, luaL_checknumber, narg, def);
 }
 
-LUALIB_API int luaL_checkinteger(lua_State* L, int narg)
+int luaL_checkboolean(lua_State* L, int narg)
+{
+    // This checks specifically for boolean values, ignoring
+    // all other truthy/falsy values. If the desired result
+    // is true if value is present then lua_toboolean should
+    // directly be used instead.
+    if (!lua_isboolean(L, narg))
+        tag_error(L, narg, LUA_TBOOLEAN);
+    return lua_toboolean(L, narg);
+}
+
+int luaL_optboolean(lua_State* L, int narg, int def)
+{
+    return luaL_opt(L, luaL_checkboolean, narg, def);
+}
+
+int luaL_checkinteger(lua_State* L, int narg)
 {
     int isnum;
     int d = lua_tointegerx(L, narg, &isnum);
@@ -192,12 +208,12 @@ LUALIB_API int luaL_checkinteger(lua_State* L, int narg)
     return d;
 }
 
-LUALIB_API int luaL_optinteger(lua_State* L, int narg, int def)
+int luaL_optinteger(lua_State* L, int narg, int def)
 {
     return luaL_opt(L, luaL_checkinteger, narg, def);
 }
 
-LUALIB_API unsigned luaL_checkunsigned(lua_State* L, int narg)
+unsigned luaL_checkunsigned(lua_State* L, int narg)
 {
     int isnum;
     unsigned d = lua_tounsignedx(L, narg, &isnum);
@@ -206,12 +222,25 @@ LUALIB_API unsigned luaL_checkunsigned(lua_State* L, int narg)
     return d;
 }
 
-LUALIB_API unsigned luaL_optunsigned(lua_State* L, int narg, unsigned def)
+unsigned luaL_optunsigned(lua_State* L, int narg, unsigned def)
 {
     return luaL_opt(L, luaL_checkunsigned, narg, def);
 }
 
-LUALIB_API int luaL_getmetafield(lua_State* L, int obj, const char* event)
+const float* luaL_checkvector(lua_State* L, int narg)
+{
+    const float* v = lua_tovector(L, narg);
+    if (!v)
+        tag_error(L, narg, LUA_TVECTOR);
+    return v;
+}
+
+const float* luaL_optvector(lua_State* L, int narg, const float* def)
+{
+    return luaL_opt(L, luaL_checkvector, narg, def);
+}
+
+int luaL_getmetafield(lua_State* L, int obj, const char* event)
 {
     if (!lua_getmetatable(L, obj)) /* no metatable? */
         return 0;
@@ -229,7 +258,7 @@ LUALIB_API int luaL_getmetafield(lua_State* L, int obj, const char* event)
     }
 }
 
-LUALIB_API int luaL_callmeta(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? */
@@ -247,7 +276,7 @@ static int libsize(const luaL_Reg* l)
     return size;
 }
 
-LUALIB_API void luaL_register(lua_State* L, const char* libname, const luaL_Reg* l)
+void luaL_register(lua_State* L, const char* libname, const luaL_Reg* l)
 {
     if (libname)
     {
@@ -273,7 +302,7 @@ LUALIB_API void luaL_register(lua_State* L, const char* libname, const luaL_Reg*
     }
 }
 
-LUALIB_API const char* luaL_findtable(lua_State* L, int idx, const char* fname, int szhint)
+const char* luaL_findtable(lua_State* L, int idx, const char* fname, int szhint)
 {
     const char* e;
     lua_pushvalue(L, idx);
@@ -324,7 +353,7 @@ static size_t getnextbuffersize(lua_State* L, size_t currentsize, size_t desired
     return newsize;
 }
 
-LUALIB_API void luaL_buffinit(lua_State* L, luaL_Buffer* B)
+void luaL_buffinit(lua_State* L, luaL_Buffer* B)
 {
     // start with an internal buffer
     B->p = B->buffer;
@@ -334,14 +363,14 @@ LUALIB_API void luaL_buffinit(lua_State* L, luaL_Buffer* B)
     B->storage = nullptr;
 }
 
-LUALIB_API char* luaL_buffinitsize(lua_State* L, luaL_Buffer* B, size_t size)
+char* luaL_buffinitsize(lua_State* L, luaL_Buffer* B, size_t size)
 {
     luaL_buffinit(L, B);
     luaL_reservebuffer(B, size, -1);
     return B->p;
 }
 
-LUALIB_API char* luaL_extendbuffer(luaL_Buffer* B, size_t additionalsize, int boxloc)
+char* luaL_extendbuffer(luaL_Buffer* B, size_t additionalsize, int boxloc)
 {
     lua_State* L = B->L;
 
@@ -372,13 +401,13 @@ LUALIB_API char* luaL_extendbuffer(luaL_Buffer* B, size_t additionalsize, int bo
     return B->p;
 }
 
-LUALIB_API void luaL_reservebuffer(luaL_Buffer* B, size_t size, int boxloc)
+void luaL_reservebuffer(luaL_Buffer* B, size_t size, int boxloc)
 {
     if (size_t(B->end - B->p) < size)
         luaL_extendbuffer(B, size - (B->end - B->p), boxloc);
 }
 
-LUALIB_API void luaL_addlstring(luaL_Buffer* B, const char* s, size_t len)
+void luaL_addlstring(luaL_Buffer* B, const char* s, size_t len)
 {
     if (size_t(B->end - B->p) < len)
         luaL_extendbuffer(B, len - (B->end - B->p), -1);
@@ -387,7 +416,7 @@ LUALIB_API void luaL_addlstring(luaL_Buffer* B, const char* s, size_t len)
     B->p += len;
 }
 
-LUALIB_API void luaL_addvalue(luaL_Buffer* B)
+void luaL_addvalue(luaL_Buffer* B)
 {
     lua_State* L = B->L;
 
@@ -404,7 +433,7 @@ LUALIB_API void luaL_addvalue(luaL_Buffer* B)
     }
 }
 
-LUALIB_API void luaL_pushresult(luaL_Buffer* B)
+void luaL_pushresult(luaL_Buffer* B)
 {
     lua_State* L = B->L;
 
@@ -428,7 +457,7 @@ LUALIB_API void luaL_pushresult(luaL_Buffer* B)
     }
 }
 
-LUALIB_API void luaL_pushresultsize(luaL_Buffer* B, size_t size)
+void luaL_pushresultsize(luaL_Buffer* B, size_t size)
 {
     B->p += size;
     luaL_pushresult(B);
@@ -436,7 +465,7 @@ LUALIB_API void luaL_pushresultsize(luaL_Buffer* B, size_t size)
 
 /* }====================================================== */
 
-LUALIB_API const char* luaL_tolstring(lua_State* L, int idx, size_t* len)
+const char* luaL_tolstring(lua_State* L, int idx, size_t* len)
 {
     if (luaL_callmeta(L, idx, "__tostring")) /* is there a metafield? */
     {
@@ -462,7 +491,11 @@ LUALIB_API const char* luaL_tolstring(lua_State* L, int idx, size_t* len)
     case LUA_TVECTOR:
     {
         const float* v = lua_tovector(L, idx);
+#if LUA_VECTOR_SIZE == 4
+        lua_pushfstring(L, LUA_NUMBER_FMT ", " LUA_NUMBER_FMT ", " LUA_NUMBER_FMT ", " LUA_NUMBER_FMT, v[0], v[1], v[2], v[3]);
+#else
         lua_pushfstring(L, LUA_NUMBER_FMT ", " LUA_NUMBER_FMT ", " LUA_NUMBER_FMT, v[0], v[1], v[2]);
+#endif
         break;
     }
     default:

VM/src/lbaselib.cpp

@@ -401,7 +401,7 @@ static int luaB_newproxy(lua_State* L)
 
     bool needsmt = lua_toboolean(L, 1);
 
-    lua_newuserdata(L, 0, 0);
+    lua_newuserdata(L, 0);
 
     if (needsmt)
     {
@@ -441,7 +441,7 @@ static void auxopen(lua_State* L, const char* name, lua_CFunction f, lua_CFuncti
     lua_setfield(L, -2, name);
 }
 
-LUALIB_API int luaopen_base(lua_State* L)
+int luaopen_base(lua_State* L)
 {
     /* set global _G */
     lua_pushvalue(L, LUA_GLOBALSINDEX);

VM/src/lbitlib.cpp

@@ -236,7 +236,7 @@ static const luaL_Reg bitlib[] = {
     {NULL, NULL},
 };
 
-LUALIB_API int luaopen_bit32(lua_State* L)
+int luaopen_bit32(lua_State* L)
 {
     luaL_register(L, LUA_BITLIBNAME, bitlib);
 

VM/src/lbuiltins.cpp

@@ -1018,13 +1018,23 @@ static int luauF_tunpack(lua_State* L, StkId res, TValue* arg0, int nresults, St
 
 static int luauF_vector(lua_State* L, StkId res, TValue* arg0, int nresults, StkId args, int nparams)
 {
+#if LUA_VECTOR_SIZE == 4
+    if (nparams >= 4 && nresults <= 1 && ttisnumber(arg0) && ttisnumber(args) && ttisnumber(args + 1) && ttisnumber(args + 2))
+#else
     if (nparams >= 3 && nresults <= 1 && ttisnumber(arg0) && ttisnumber(args) && ttisnumber(args + 1))
+#endif
     {
         double x = nvalue(arg0);
         double y = nvalue(args);
         double z = nvalue(args + 1);
 
-        setvvalue(res, float(x), float(y), float(z));
+#if LUA_VECTOR_SIZE == 4
+        double w = nvalue(args + 2);
+        setvvalue(res, float(x), float(y), float(z), float(w));
+#else
+        setvvalue(res, float(x), float(y), float(z), 0.0f);
+#endif
+
         return 1;
     }
 

VM/src/lcorolib.cpp

@@ -272,7 +272,7 @@ static const luaL_Reg co_funcs[] = {
     {NULL, NULL},
 };
 
-LUALIB_API int luaopen_coroutine(lua_State* L)
+int luaopen_coroutine(lua_State* L)
 {
     luaL_register(L, LUA_COLIBNAME, co_funcs);
 

VM/src/ldblib.cpp

@@ -160,7 +160,7 @@ static const luaL_Reg dblib[] = {
     {NULL, NULL},
 };
 
-LUALIB_API int luaopen_debug(lua_State* L)
+int luaopen_debug(lua_State* L)
 {
     luaL_register(L, LUA_DBLIBNAME, dblib);
     return 1;

VM/src/ldo.cpp

@@ -17,9 +17,9 @@
 
 #include <string.h>
 
-LUAU_FASTFLAGVARIABLE(LuauExceptionMessageFix, false)
 LUAU_FASTFLAGVARIABLE(LuauCcallRestoreFix, false)
 LUAU_FASTFLAG(LuauCoroutineClose)
+LUAU_FASTFLAGVARIABLE(LuauActivateBeforeExec, false)
 
 /*
 ** {======================================================
@@ -74,35 +74,28 @@ public:
 
     const char* what() const throw() override
     {
-        if (FFlag::LuauExceptionMessageFix)
+        // LUA_ERRRUN/LUA_ERRSYNTAX pass an object on the stack which is intended to describe the error.
+        if (status == LUA_ERRRUN || status == LUA_ERRSYNTAX)
         {
-            // LUA_ERRRUN/LUA_ERRSYNTAX pass an object on the stack which is intended to describe the error.
+            // Conversion to a string could still fail.  For example if a user passes a non-string/non-number argument to `error()`.
-            if (status == LUA_ERRRUN || status == LUA_ERRSYNTAX)
+            if (const char* str = lua_tostring(L, -1))
             {
-                // Conversion to a string could still fail.  For example if a user passes a non-string/non-number argument to `error()`.
+                return str;
-                if (const char* str = lua_tostring(L, -1))
-                {
-                    return str;
-                }
-            }
-
-            switch (status)
-            {
-            case LUA_ERRRUN:
-                return "lua_exception: LUA_ERRRUN (no string/number provided as description)";
-            case LUA_ERRSYNTAX:
-                return "lua_exception: LUA_ERRSYNTAX (no string/number provided as description)";
-            case LUA_ERRMEM:
-                return "lua_exception: " LUA_MEMERRMSG;
-            case LUA_ERRERR:
-                return "lua_exception: " LUA_ERRERRMSG;
-            default:
-                return "lua_exception: unexpected exception status";
             }
         }
-        else
+
+        switch (status)
         {
-            return lua_tostring(L, -1);
+        case LUA_ERRRUN:
+            return "lua_exception: LUA_ERRRUN (no string/number provided as description)";
+        case LUA_ERRSYNTAX:
+            return "lua_exception: LUA_ERRSYNTAX (no string/number provided as description)";
+        case LUA_ERRMEM:
+            return "lua_exception: " LUA_MEMERRMSG;
+        case LUA_ERRERR:
+            return "lua_exception: " LUA_ERRERRMSG;
+        default:
+            return "lua_exception: unexpected exception status";
         }
     }
 
@@ -234,7 +227,22 @@ void luaD_call(lua_State* L, StkId func, int nResults)
     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 */
-        luau_execute(L);                     /* call it */
+
+        if (FFlag::LuauActivateBeforeExec)
+        {
+            int oldactive = luaC_threadactive(L);
+            l_setbit(L->stackstate, THREAD_ACTIVEBIT);
+            luaC_checkthreadsleep(L);
+
+            luau_execute(L); /* call it */
+
+            if (!oldactive)
+                resetbit(L->stackstate, THREAD_ACTIVEBIT);
+        }
+        else
+        {
+            luau_execute(L); /* call it */
+        }
     }
     L->nCcalls--;
     luaC_checkGC(L);
@@ -527,10 +535,10 @@ static void restore_stack_limit(lua_State* L)
 
 int luaD_pcall(lua_State* L, Pfunc func, void* u, ptrdiff_t old_top, ptrdiff_t ef)
 {
-    int status;
     unsigned short oldnCcalls = L->nCcalls;
     ptrdiff_t old_ci = saveci(L, L->ci);
-    status = luaD_rawrunprotected(L, func, u);
+    int oldactive = luaC_threadactive(L);
+    int status = luaD_rawrunprotected(L, func, u);
     if (status != 0)
     {
         // call user-defined error function (used in xpcall)
@@ -541,6 +549,13 @@ int luaD_pcall(lua_State* L, Pfunc func, void* u, ptrdiff_t old_top, ptrdiff_t e
                 status = LUA_ERRERR;
         }
 
+        if (FFlag::LuauActivateBeforeExec)
+        {
+            // since the call failed with an error, we might have to reset the 'active' thread state
+            if (!oldactive)
+                resetbit(L->stackstate, THREAD_ACTIVEBIT);
+        }
+
         if (FFlag::LuauCcallRestoreFix)
         {
             // Restore nCcalls before calling the debugprotectederror callback which may rely on the proper value to have been restored.

VM/src/lgc.cpp

@@ -10,9 +10,7 @@
 #include "ldo.h"
 
 #include <string.h>
-#include <stdio.h>
 
-LUAU_FASTFLAGVARIABLE(LuauRescanGrayAgainForwardBarrier, false)
 LUAU_FASTFLAGVARIABLE(LuauSeparateAtomic, false)
 
 LUAU_FASTFLAG(LuauArrayBoundary)
@@ -988,7 +986,7 @@ void luaC_barriertable(lua_State* L, Table* t, GCObject* v)
     GCObject* o = obj2gco(t);
 
     // in the second propagation stage, table assignment barrier works as a forward barrier
-    if (FFlag::LuauRescanGrayAgainForwardBarrier && g->gcstate == GCSpropagateagain)
+    if (g->gcstate == GCSpropagateagain)
     {
         LUAU_ASSERT(isblack(o) && iswhite(v) && !isdead(g, v) && !isdead(g, o));
         reallymarkobject(g, v);
@@ -1044,550 +1042,6 @@ void luaC_linkupval(lua_State* L, UpVal* uv)
     }
 }
 
-static void validateobjref(global_State* g, GCObject* f, GCObject* t)
-{
-    LUAU_ASSERT(!isdead(g, t));
-
-    if (keepinvariant(g))
-    {
-        /* basic incremental invariant: black can't point to white */
-        LUAU_ASSERT(!(isblack(f) && iswhite(t)));
-    }
-}
-
-static void validateref(global_State* g, GCObject* f, TValue* v)
-{
-    if (iscollectable(v))
-    {
-        LUAU_ASSERT(ttype(v) == gcvalue(v)->gch.tt);
-        validateobjref(g, f, gcvalue(v));
-    }
-}
-
-static void validatetable(global_State* g, Table* h)
-{
-    int sizenode = 1 << h->lsizenode;
-
-    if (FFlag::LuauArrayBoundary)
-        LUAU_ASSERT(h->lastfree <= sizenode);
-    else
-        LUAU_ASSERT(h->lastfree >= 0 && h->lastfree <= sizenode);
-
-    if (h->metatable)
-        validateobjref(g, obj2gco(h), obj2gco(h->metatable));
-
-    for (int i = 0; i < h->sizearray; ++i)
-        validateref(g, obj2gco(h), &h->array[i]);
-
-    for (int i = 0; i < sizenode; ++i)
-    {
-        LuaNode* n = &h->node[i];
-
-        LUAU_ASSERT(ttype(gkey(n)) != LUA_TDEADKEY || ttisnil(gval(n)));
-        LUAU_ASSERT(i + gnext(n) >= 0 && i + gnext(n) < sizenode);
-
-        if (!ttisnil(gval(n)))
-        {
-            TValue k = {};
-            k.tt = gkey(n)->tt;
-            k.value = gkey(n)->value;
-
-            validateref(g, obj2gco(h), &k);
-            validateref(g, obj2gco(h), gval(n));
-        }
-    }
-}
-
-static void validateclosure(global_State* g, Closure* cl)
-{
-    validateobjref(g, obj2gco(cl), obj2gco(cl->env));
-
-    if (cl->isC)
-    {
-        for (int i = 0; i < cl->nupvalues; ++i)
-            validateref(g, obj2gco(cl), &cl->c.upvals[i]);
-    }
-    else
-    {
-        LUAU_ASSERT(cl->nupvalues == cl->l.p->nups);
-
-        validateobjref(g, obj2gco(cl), obj2gco(cl->l.p));
-
-        for (int i = 0; i < cl->nupvalues; ++i)
-            validateref(g, obj2gco(cl), &cl->l.uprefs[i]);
-    }
-}
-
-static void validatestack(global_State* g, lua_State* l)
-{
-    validateref(g, obj2gco(l), gt(l));
-
-    for (CallInfo* ci = l->base_ci; ci <= l->ci; ++ci)
-    {
-        LUAU_ASSERT(l->stack <= ci->base);
-        LUAU_ASSERT(ci->func <= ci->base && ci->base <= ci->top);
-        LUAU_ASSERT(ci->top <= l->stack_last);
-    }
-
-    // note: stack refs can violate gc invariant so we only check for liveness
-    for (StkId o = l->stack; o < l->top; ++o)
-        checkliveness(g, o);
-
-    if (l->namecall)
-        validateobjref(g, obj2gco(l), obj2gco(l->namecall));
-
-    for (GCObject* uv = l->openupval; uv; uv = uv->gch.next)
-    {
-        LUAU_ASSERT(uv->gch.tt == LUA_TUPVAL);
-        LUAU_ASSERT(gco2uv(uv)->v != &gco2uv(uv)->u.value);
-    }
-}
-
-static void validateproto(global_State* g, Proto* f)
-{
-    if (f->source)
-        validateobjref(g, obj2gco(f), obj2gco(f->source));
-
-    if (f->debugname)
-        validateobjref(g, obj2gco(f), obj2gco(f->debugname));
-
-    for (int i = 0; i < f->sizek; ++i)
-        validateref(g, obj2gco(f), &f->k[i]);
-
-    for (int i = 0; i < f->sizeupvalues; ++i)
-        if (f->upvalues[i])
-            validateobjref(g, obj2gco(f), obj2gco(f->upvalues[i]));
-
-    for (int i = 0; i < f->sizep; ++i)
-        if (f->p[i])
-            validateobjref(g, obj2gco(f), obj2gco(f->p[i]));
-
-    for (int i = 0; i < f->sizelocvars; i++)
-        if (f->locvars[i].varname)
-            validateobjref(g, obj2gco(f), obj2gco(f->locvars[i].varname));
-}
-
-static void validateobj(global_State* g, GCObject* o)
-{
-    /* dead objects can only occur during sweep */
-    if (isdead(g, o))
-    {
-        LUAU_ASSERT(g->gcstate == GCSsweepstring || g->gcstate == GCSsweep);
-        return;
-    }
-
-    switch (o->gch.tt)
-    {
-    case LUA_TSTRING:
-        break;
-
-    case LUA_TTABLE:
-        validatetable(g, gco2h(o));
-        break;
-
-    case LUA_TFUNCTION:
-        validateclosure(g, gco2cl(o));
-        break;
-
-    case LUA_TUSERDATA:
-        if (gco2u(o)->metatable)
-            validateobjref(g, o, obj2gco(gco2u(o)->metatable));
-        break;
-
-    case LUA_TTHREAD:
-        validatestack(g, gco2th(o));
-        break;
-
-    case LUA_TPROTO:
-        validateproto(g, gco2p(o));
-        break;
-
-    case LUA_TUPVAL:
-        validateref(g, o, gco2uv(o)->v);
-        break;
-
-    default:
-        LUAU_ASSERT(!"unexpected object type");
-    }
-}
-
-static void validatelist(global_State* g, GCObject* o)
-{
-    while (o)
-    {
-        validateobj(g, o);
-
-        o = o->gch.next;
-    }
-}
-
-static void validategraylist(global_State* g, GCObject* o)
-{
-    if (!keepinvariant(g))
-        return;
-
-    while (o)
-    {
-        LUAU_ASSERT(isgray(o));
-
-        switch (o->gch.tt)
-        {
-        case LUA_TTABLE:
-            o = gco2h(o)->gclist;
-            break;
-        case LUA_TFUNCTION:
-            o = gco2cl(o)->gclist;
-            break;
-        case LUA_TTHREAD:
-            o = gco2th(o)->gclist;
-            break;
-        case LUA_TPROTO:
-            o = gco2p(o)->gclist;
-            break;
-        default:
-            LUAU_ASSERT(!"unknown object in gray list");
-            return;
-        }
-    }
-}
-
-void luaC_validate(lua_State* L)
-{
-    global_State* g = L->global;
-
-    LUAU_ASSERT(!isdead(g, obj2gco(g->mainthread)));
-    checkliveness(g, &g->registry);
-
-    for (int i = 0; i < LUA_T_COUNT; ++i)
-        if (g->mt[i])
-            LUAU_ASSERT(!isdead(g, obj2gco(g->mt[i])));
-
-    validategraylist(g, g->weak);
-    validategraylist(g, g->gray);
-    validategraylist(g, g->grayagain);
-
-    for (int i = 0; i < g->strt.size; ++i)
-        validatelist(g, g->strt.hash[i]);
-
-    validatelist(g, g->rootgc);
-    validatelist(g, g->strbufgc);
-
-    for (UpVal* uv = g->uvhead.u.l.next; uv != &g->uvhead; uv = uv->u.l.next)
-    {
-        LUAU_ASSERT(uv->tt == LUA_TUPVAL);
-        LUAU_ASSERT(uv->v != &uv->u.value);
-        LUAU_ASSERT(uv->u.l.next->u.l.prev == uv && uv->u.l.prev->u.l.next == uv);
-    }
-}
-
-inline bool safejson(char ch)
-{
-    return unsigned(ch) < 128 && ch >= 32 && ch != '\\' && ch != '\"';
-}
-
-static void dumpref(FILE* f, GCObject* o)
-{
-    fprintf(f, "\"%p\"", o);
-}
-
-static void dumprefs(FILE* f, TValue* data, size_t size)
-{
-    bool first = true;
-
-    for (size_t i = 0; i < size; ++i)
-    {
-        if (iscollectable(&data[i]))
-        {
-            if (!first)
-                fputc(',', f);
-            first = false;
-
-            dumpref(f, gcvalue(&data[i]));
-        }
-    }
-}
-
-static void dumpstringdata(FILE* f, const char* data, size_t len)
-{
-    for (size_t i = 0; i < len; ++i)
-        fputc(safejson(data[i]) ? data[i] : '?', f);
-}
-
-static void dumpstring(FILE* f, TString* ts)
-{
-    fprintf(f, "{\"type\":\"string\",\"cat\":%d,\"size\":%d,\"data\":\"", ts->memcat, int(sizestring(ts->len)));
-    dumpstringdata(f, ts->data, ts->len);
-    fprintf(f, "\"}");
-}
-
-static void dumptable(FILE* f, Table* h)
-{
-    size_t size = sizeof(Table) + (h->node == &luaH_dummynode ? 0 : sizenode(h) * sizeof(LuaNode)) + h->sizearray * sizeof(TValue);
-
-    fprintf(f, "{\"type\":\"table\",\"cat\":%d,\"size\":%d", h->memcat, int(size));
-
-    if (h->node != &luaH_dummynode)
-    {
-        fprintf(f, ",\"pairs\":[");
-
-        bool first = true;
-
-        for (int i = 0; i < sizenode(h); ++i)
-        {
-            const LuaNode& n = h->node[i];
-
-            if (!ttisnil(&n.val) && (iscollectable(&n.key) || iscollectable(&n.val)))
-            {
-                if (!first)
-                    fputc(',', f);
-                first = false;
-
-                if (iscollectable(&n.key))
-                    dumpref(f, gcvalue(&n.key));
-                else
-                    fprintf(f, "null");
-
-                fputc(',', f);
-
-                if (iscollectable(&n.val))
-                    dumpref(f, gcvalue(&n.val));
-                else
-                    fprintf(f, "null");
-            }
-        }
-
-        fprintf(f, "]");
-    }
-    if (h->sizearray)
-    {
-        fprintf(f, ",\"array\":[");
-        dumprefs(f, h->array, h->sizearray);
-        fprintf(f, "]");
-    }
-    if (h->metatable)
-    {
-        fprintf(f, ",\"metatable\":");
-        dumpref(f, obj2gco(h->metatable));
-    }
-    fprintf(f, "}");
-}
-
-static void dumpclosure(FILE* f, Closure* cl)
-{
-    fprintf(f, "{\"type\":\"function\",\"cat\":%d,\"size\":%d", cl->memcat,
-        cl->isC ? int(sizeCclosure(cl->nupvalues)) : int(sizeLclosure(cl->nupvalues)));
-
-    fprintf(f, ",\"env\":");
-    dumpref(f, obj2gco(cl->env));
-    if (cl->isC)
-    {
-        if (cl->nupvalues)
-        {
-            fprintf(f, ",\"upvalues\":[");
-            dumprefs(f, cl->c.upvals, cl->nupvalues);
-            fprintf(f, "]");
-        }
-    }
-    else
-    {
-        fprintf(f, ",\"proto\":");
-        dumpref(f, obj2gco(cl->l.p));
-        if (cl->nupvalues)
-        {
-            fprintf(f, ",\"upvalues\":[");
-            dumprefs(f, cl->l.uprefs, cl->nupvalues);
-            fprintf(f, "]");
-        }
-    }
-    fprintf(f, "}");
-}
-
-static void dumpudata(FILE* f, Udata* u)
-{
-    fprintf(f, "{\"type\":\"userdata\",\"cat\":%d,\"size\":%d,\"tag\":%d", u->memcat, int(sizeudata(u->len)), u->tag);
-
-    if (u->metatable)
-    {
-        fprintf(f, ",\"metatable\":");
-        dumpref(f, obj2gco(u->metatable));
-    }
-    fprintf(f, "}");
-}
-
-static void dumpthread(FILE* f, lua_State* th)
-{
-    size_t size = sizeof(lua_State) + sizeof(TValue) * th->stacksize + sizeof(CallInfo) * th->size_ci;
-
-    fprintf(f, "{\"type\":\"thread\",\"cat\":%d,\"size\":%d", th->memcat, int(size));
-
-    if (iscollectable(&th->l_gt))
-    {
-        fprintf(f, ",\"env\":");
-        dumpref(f, gcvalue(&th->l_gt));
-    }
-
-    Closure* tcl = 0;
-    for (CallInfo* ci = th->base_ci; ci <= th->ci; ++ci)
-    {
-        if (ttisfunction(ci->func))
-        {
-            tcl = clvalue(ci->func);
-            break;
-        }
-    }
-
-    if (tcl && !tcl->isC && tcl->l.p->source)
-    {
-        Proto* p = tcl->l.p;
-
-        fprintf(f, ",\"source\":\"");
-        dumpstringdata(f, p->source->data, p->source->len);
-        fprintf(f, "\",\"line\":%d", p->abslineinfo ? p->abslineinfo[0] : 0);
-    }
-
-    if (th->top > th->stack)
-    {
-        fprintf(f, ",\"stack\":[");
-        dumprefs(f, th->stack, th->top - th->stack);
-        fprintf(f, "]");
-    }
-    fprintf(f, "}");
-}
-
-static void dumpproto(FILE* f, Proto* p)
-{
-    size_t size = sizeof(Proto) + sizeof(Instruction) * p->sizecode + sizeof(Proto*) * p->sizep + sizeof(TValue) * p->sizek + p->sizelineinfo +
-                  sizeof(LocVar) * p->sizelocvars + sizeof(TString*) * p->sizeupvalues;
-
-    fprintf(f, "{\"type\":\"proto\",\"cat\":%d,\"size\":%d", p->memcat, int(size));
-
-    if (p->source)
-    {
-        fprintf(f, ",\"source\":\"");
-        dumpstringdata(f, p->source->data, p->source->len);
-        fprintf(f, "\",\"line\":%d", p->abslineinfo ? p->abslineinfo[0] : 0);
-    }
-
-    if (p->sizek)
-    {
-        fprintf(f, ",\"constants\":[");
-        dumprefs(f, p->k, p->sizek);
-        fprintf(f, "]");
-    }
-
-    if (p->sizep)
-    {
-        fprintf(f, ",\"protos\":[");
-        for (int i = 0; i < p->sizep; ++i)
-        {
-            if (i != 0)
-                fputc(',', f);
-            dumpref(f, obj2gco(p->p[i]));
-        }
-        fprintf(f, "]");
-    }
-
-    fprintf(f, "}");
-}
-
-static void dumpupval(FILE* f, UpVal* uv)
-{
-    fprintf(f, "{\"type\":\"upvalue\",\"cat\":%d,\"size\":%d", uv->memcat, int(sizeof(UpVal)));
-
-    if (iscollectable(uv->v))
-    {
-        fprintf(f, ",\"object\":");
-        dumpref(f, gcvalue(uv->v));
-    }
-    fprintf(f, "}");
-}
-
-static void dumpobj(FILE* f, GCObject* o)
-{
-    switch (o->gch.tt)
-    {
-    case LUA_TSTRING:
-        return dumpstring(f, gco2ts(o));
-
-    case LUA_TTABLE:
-        return dumptable(f, gco2h(o));
-
-    case LUA_TFUNCTION:
-        return dumpclosure(f, gco2cl(o));
-
-    case LUA_TUSERDATA:
-        return dumpudata(f, gco2u(o));
-
-    case LUA_TTHREAD:
-        return dumpthread(f, gco2th(o));
-
-    case LUA_TPROTO:
-        return dumpproto(f, gco2p(o));
-
-    case LUA_TUPVAL:
-        return dumpupval(f, gco2uv(o));
-
-    default:
-        LUAU_ASSERT(0);
-    }
-}
-
-static void dumplist(FILE* f, GCObject* o)
-{
-    while (o)
-    {
-        dumpref(f, o);
-        fputc(':', f);
-        dumpobj(f, o);
-        fputc(',', f);
-        fputc('\n', f);
-
-        // thread has additional list containing collectable objects that are not present in rootgc
-        if (o->gch.tt == LUA_TTHREAD)
-            dumplist(f, gco2th(o)->openupval);
-
-        o = o->gch.next;
-    }
-}
-
-void luaC_dump(lua_State* L, void* file, const char* (*categoryName)(lua_State* L, uint8_t memcat))
-{
-    global_State* g = L->global;
-    FILE* f = static_cast<FILE*>(file);
-
-    fprintf(f, "{\"objects\":{\n");
-    dumplist(f, g->rootgc);
-    dumplist(f, g->strbufgc);
-    for (int i = 0; i < g->strt.size; ++i)
-        dumplist(f, g->strt.hash[i]);
-
-    fprintf(f, "\"0\":{\"type\":\"userdata\",\"cat\":0,\"size\":0}\n"); // to avoid issues with trailing ,
-    fprintf(f, "},\"roots\":{\n");
-    fprintf(f, "\"mainthread\":");
-    dumpref(f, obj2gco(g->mainthread));
-    fprintf(f, ",\"registry\":");
-    dumpref(f, gcvalue(&g->registry));
-
-    fprintf(f, "},\"stats\":{\n");
-
-    fprintf(f, "\"size\":%d,\n", int(g->totalbytes));
-
-    fprintf(f, "\"categories\":{\n");
-    for (int i = 0; i < LUA_MEMORY_CATEGORIES; i++)
-    {
-        if (size_t bytes = g->memcatbytes[i])
-        {
-            if (categoryName)
-                fprintf(f, "\"%d\":{\"name\":\"%s\", \"size\":%d},\n", i, categoryName(L, i), int(bytes));
-            else
-                fprintf(f, "\"%d\":{\"size\":%d},\n", i, int(bytes));
-        }
-    }
-    fprintf(f, "\"none\":{}\n"); // to avoid issues with trailing ,
-    fprintf(f, "}\n");
-    fprintf(f, "}}\n");
-}
-
 // measure the allocation rate in bytes/sec
 // returns -1 if allocation rate cannot be measured
 int64_t luaC_allocationrate(lua_State* L)

VM/src/lgcdebug.cpp

@@ -0,0 +1,558 @@
+// This file is part of the Luau programming language and is licensed under MIT License; see LICENSE.txt for details
+// This code is based on Lua 5.x implementation licensed under MIT License; see lua_LICENSE.txt for details
+#include "lgc.h"
+
+#include "lobject.h"
+#include "lstate.h"
+#include "ltable.h"
+#include "lfunc.h"
+#include "lstring.h"
+
+#include <string.h>
+#include <stdio.h>
+
+LUAU_FASTFLAG(LuauArrayBoundary)
+
+static void validateobjref(global_State* g, GCObject* f, GCObject* t)
+{
+    LUAU_ASSERT(!isdead(g, t));
+
+    if (keepinvariant(g))
+    {
+        /* basic incremental invariant: black can't point to white */
+        LUAU_ASSERT(!(isblack(f) && iswhite(t)));
+    }
+}
+
+static void validateref(global_State* g, GCObject* f, TValue* v)
+{
+    if (iscollectable(v))
+    {
+        LUAU_ASSERT(ttype(v) == gcvalue(v)->gch.tt);
+        validateobjref(g, f, gcvalue(v));
+    }
+}
+
+static void validatetable(global_State* g, Table* h)
+{
+    int sizenode = 1 << h->lsizenode;
+
+    if (FFlag::LuauArrayBoundary)
+        LUAU_ASSERT(h->lastfree <= sizenode);
+    else
+        LUAU_ASSERT(h->lastfree >= 0 && h->lastfree <= sizenode);
+
+    if (h->metatable)
+        validateobjref(g, obj2gco(h), obj2gco(h->metatable));
+
+    for (int i = 0; i < h->sizearray; ++i)
+        validateref(g, obj2gco(h), &h->array[i]);
+
+    for (int i = 0; i < sizenode; ++i)
+    {
+        LuaNode* n = &h->node[i];
+
+        LUAU_ASSERT(ttype(gkey(n)) != LUA_TDEADKEY || ttisnil(gval(n)));
+        LUAU_ASSERT(i + gnext(n) >= 0 && i + gnext(n) < sizenode);
+
+        if (!ttisnil(gval(n)))
+        {
+            TValue k = {};
+            k.tt = gkey(n)->tt;
+            k.value = gkey(n)->value;
+
+            validateref(g, obj2gco(h), &k);
+            validateref(g, obj2gco(h), gval(n));
+        }
+    }
+}
+
+static void validateclosure(global_State* g, Closure* cl)
+{
+    validateobjref(g, obj2gco(cl), obj2gco(cl->env));
+
+    if (cl->isC)
+    {
+        for (int i = 0; i < cl->nupvalues; ++i)
+            validateref(g, obj2gco(cl), &cl->c.upvals[i]);
+    }
+    else
+    {
+        LUAU_ASSERT(cl->nupvalues == cl->l.p->nups);
+
+        validateobjref(g, obj2gco(cl), obj2gco(cl->l.p));
+
+        for (int i = 0; i < cl->nupvalues; ++i)
+            validateref(g, obj2gco(cl), &cl->l.uprefs[i]);
+    }
+}
+
+static void validatestack(global_State* g, lua_State* l)
+{
+    validateref(g, obj2gco(l), gt(l));
+
+    for (CallInfo* ci = l->base_ci; ci <= l->ci; ++ci)
+    {
+        LUAU_ASSERT(l->stack <= ci->base);
+        LUAU_ASSERT(ci->func <= ci->base && ci->base <= ci->top);
+        LUAU_ASSERT(ci->top <= l->stack_last);
+    }
+
+    // note: stack refs can violate gc invariant so we only check for liveness
+    for (StkId o = l->stack; o < l->top; ++o)
+        checkliveness(g, o);
+
+    if (l->namecall)
+        validateobjref(g, obj2gco(l), obj2gco(l->namecall));
+
+    for (GCObject* uv = l->openupval; uv; uv = uv->gch.next)
+    {
+        LUAU_ASSERT(uv->gch.tt == LUA_TUPVAL);
+        LUAU_ASSERT(gco2uv(uv)->v != &gco2uv(uv)->u.value);
+    }
+}
+
+static void validateproto(global_State* g, Proto* f)
+{
+    if (f->source)
+        validateobjref(g, obj2gco(f), obj2gco(f->source));
+
+    if (f->debugname)
+        validateobjref(g, obj2gco(f), obj2gco(f->debugname));
+
+    for (int i = 0; i < f->sizek; ++i)
+        validateref(g, obj2gco(f), &f->k[i]);
+
+    for (int i = 0; i < f->sizeupvalues; ++i)
+        if (f->upvalues[i])
+            validateobjref(g, obj2gco(f), obj2gco(f->upvalues[i]));
+
+    for (int i = 0; i < f->sizep; ++i)
+        if (f->p[i])
+            validateobjref(g, obj2gco(f), obj2gco(f->p[i]));
+
+    for (int i = 0; i < f->sizelocvars; i++)
+        if (f->locvars[i].varname)
+            validateobjref(g, obj2gco(f), obj2gco(f->locvars[i].varname));
+}
+
+static void validateobj(global_State* g, GCObject* o)
+{
+    /* dead objects can only occur during sweep */
+    if (isdead(g, o))
+    {
+        LUAU_ASSERT(g->gcstate == GCSsweepstring || g->gcstate == GCSsweep);
+        return;
+    }
+
+    switch (o->gch.tt)
+    {
+    case LUA_TSTRING:
+        break;
+
+    case LUA_TTABLE:
+        validatetable(g, gco2h(o));
+        break;
+
+    case LUA_TFUNCTION:
+        validateclosure(g, gco2cl(o));
+        break;
+
+    case LUA_TUSERDATA:
+        if (gco2u(o)->metatable)
+            validateobjref(g, o, obj2gco(gco2u(o)->metatable));
+        break;
+
+    case LUA_TTHREAD:
+        validatestack(g, gco2th(o));
+        break;
+
+    case LUA_TPROTO:
+        validateproto(g, gco2p(o));
+        break;
+
+    case LUA_TUPVAL:
+        validateref(g, o, gco2uv(o)->v);
+        break;
+
+    default:
+        LUAU_ASSERT(!"unexpected object type");
+    }
+}
+
+static void validatelist(global_State* g, GCObject* o)
+{
+    while (o)
+    {
+        validateobj(g, o);
+
+        o = o->gch.next;
+    }
+}
+
+static void validategraylist(global_State* g, GCObject* o)
+{
+    if (!keepinvariant(g))
+        return;
+
+    while (o)
+    {
+        LUAU_ASSERT(isgray(o));
+
+        switch (o->gch.tt)
+        {
+        case LUA_TTABLE:
+            o = gco2h(o)->gclist;
+            break;
+        case LUA_TFUNCTION:
+            o = gco2cl(o)->gclist;
+            break;
+        case LUA_TTHREAD:
+            o = gco2th(o)->gclist;
+            break;
+        case LUA_TPROTO:
+            o = gco2p(o)->gclist;
+            break;
+        default:
+            LUAU_ASSERT(!"unknown object in gray list");
+            return;
+        }
+    }
+}
+
+void luaC_validate(lua_State* L)
+{
+    global_State* g = L->global;
+
+    LUAU_ASSERT(!isdead(g, obj2gco(g->mainthread)));
+    checkliveness(g, &g->registry);
+
+    for (int i = 0; i < LUA_T_COUNT; ++i)
+        if (g->mt[i])
+            LUAU_ASSERT(!isdead(g, obj2gco(g->mt[i])));
+
+    validategraylist(g, g->weak);
+    validategraylist(g, g->gray);
+    validategraylist(g, g->grayagain);
+
+    for (int i = 0; i < g->strt.size; ++i)
+        validatelist(g, g->strt.hash[i]);
+
+    validatelist(g, g->rootgc);
+    validatelist(g, g->strbufgc);
+
+    for (UpVal* uv = g->uvhead.u.l.next; uv != &g->uvhead; uv = uv->u.l.next)
+    {
+        LUAU_ASSERT(uv->tt == LUA_TUPVAL);
+        LUAU_ASSERT(uv->v != &uv->u.value);
+        LUAU_ASSERT(uv->u.l.next->u.l.prev == uv && uv->u.l.prev->u.l.next == uv);
+    }
+}
+
+inline bool safejson(char ch)
+{
+    return unsigned(ch) < 128 && ch >= 32 && ch != '\\' && ch != '\"';
+}
+
+static void dumpref(FILE* f, GCObject* o)
+{
+    fprintf(f, "\"%p\"", o);
+}
+
+static void dumprefs(FILE* f, TValue* data, size_t size)
+{
+    bool first = true;
+
+    for (size_t i = 0; i < size; ++i)
+    {
+        if (iscollectable(&data[i]))
+        {
+            if (!first)
+                fputc(',', f);
+            first = false;
+
+            dumpref(f, gcvalue(&data[i]));
+        }
+    }
+}
+
+static void dumpstringdata(FILE* f, const char* data, size_t len)
+{
+    for (size_t i = 0; i < len; ++i)
+        fputc(safejson(data[i]) ? data[i] : '?', f);
+}
+
+static void dumpstring(FILE* f, TString* ts)
+{
+    fprintf(f, "{\"type\":\"string\",\"cat\":%d,\"size\":%d,\"data\":\"", ts->memcat, int(sizestring(ts->len)));
+    dumpstringdata(f, ts->data, ts->len);
+    fprintf(f, "\"}");
+}
+
+static void dumptable(FILE* f, Table* h)
+{
+    size_t size = sizeof(Table) + (h->node == &luaH_dummynode ? 0 : sizenode(h) * sizeof(LuaNode)) + h->sizearray * sizeof(TValue);
+
+    fprintf(f, "{\"type\":\"table\",\"cat\":%d,\"size\":%d", h->memcat, int(size));
+
+    if (h->node != &luaH_dummynode)
+    {
+        fprintf(f, ",\"pairs\":[");
+
+        bool first = true;
+
+        for (int i = 0; i < sizenode(h); ++i)
+        {
+            const LuaNode& n = h->node[i];
+
+            if (!ttisnil(&n.val) && (iscollectable(&n.key) || iscollectable(&n.val)))
+            {
+                if (!first)
+                    fputc(',', f);
+                first = false;
+
+                if (iscollectable(&n.key))
+                    dumpref(f, gcvalue(&n.key));
+                else
+                    fprintf(f, "null");
+
+                fputc(',', f);
+
+                if (iscollectable(&n.val))
+                    dumpref(f, gcvalue(&n.val));
+                else
+                    fprintf(f, "null");
+            }
+        }
+
+        fprintf(f, "]");
+    }
+    if (h->sizearray)
+    {
+        fprintf(f, ",\"array\":[");
+        dumprefs(f, h->array, h->sizearray);
+        fprintf(f, "]");
+    }
+    if (h->metatable)
+    {
+        fprintf(f, ",\"metatable\":");
+        dumpref(f, obj2gco(h->metatable));
+    }
+    fprintf(f, "}");
+}
+
+static void dumpclosure(FILE* f, Closure* cl)
+{
+    fprintf(f, "{\"type\":\"function\",\"cat\":%d,\"size\":%d", cl->memcat,
+        cl->isC ? int(sizeCclosure(cl->nupvalues)) : int(sizeLclosure(cl->nupvalues)));
+
+    fprintf(f, ",\"env\":");
+    dumpref(f, obj2gco(cl->env));
+    if (cl->isC)
+    {
+        if (cl->nupvalues)
+        {
+            fprintf(f, ",\"upvalues\":[");
+            dumprefs(f, cl->c.upvals, cl->nupvalues);
+            fprintf(f, "]");
+        }
+    }
+    else
+    {
+        fprintf(f, ",\"proto\":");
+        dumpref(f, obj2gco(cl->l.p));
+        if (cl->nupvalues)
+        {
+            fprintf(f, ",\"upvalues\":[");
+            dumprefs(f, cl->l.uprefs, cl->nupvalues);
+            fprintf(f, "]");
+        }
+    }
+    fprintf(f, "}");
+}
+
+static void dumpudata(FILE* f, Udata* u)
+{
+    fprintf(f, "{\"type\":\"userdata\",\"cat\":%d,\"size\":%d,\"tag\":%d", u->memcat, int(sizeudata(u->len)), u->tag);
+
+    if (u->metatable)
+    {
+        fprintf(f, ",\"metatable\":");
+        dumpref(f, obj2gco(u->metatable));
+    }
+    fprintf(f, "}");
+}
+
+static void dumpthread(FILE* f, lua_State* th)
+{
+    size_t size = sizeof(lua_State) + sizeof(TValue) * th->stacksize + sizeof(CallInfo) * th->size_ci;
+
+    fprintf(f, "{\"type\":\"thread\",\"cat\":%d,\"size\":%d", th->memcat, int(size));
+
+    if (iscollectable(&th->l_gt))
+    {
+        fprintf(f, ",\"env\":");
+        dumpref(f, gcvalue(&th->l_gt));
+    }
+
+    Closure* tcl = 0;
+    for (CallInfo* ci = th->base_ci; ci <= th->ci; ++ci)
+    {
+        if (ttisfunction(ci->func))
+        {
+            tcl = clvalue(ci->func);
+            break;
+        }
+    }
+
+    if (tcl && !tcl->isC && tcl->l.p->source)
+    {
+        Proto* p = tcl->l.p;
+
+        fprintf(f, ",\"source\":\"");
+        dumpstringdata(f, p->source->data, p->source->len);
+        fprintf(f, "\",\"line\":%d", p->abslineinfo ? p->abslineinfo[0] : 0);
+    }
+
+    if (th->top > th->stack)
+    {
+        fprintf(f, ",\"stack\":[");
+        dumprefs(f, th->stack, th->top - th->stack);
+        fprintf(f, "]");
+    }
+    fprintf(f, "}");
+}
+
+static void dumpproto(FILE* f, Proto* p)
+{
+    size_t size = sizeof(Proto) + sizeof(Instruction) * p->sizecode + sizeof(Proto*) * p->sizep + sizeof(TValue) * p->sizek + p->sizelineinfo +
+                  sizeof(LocVar) * p->sizelocvars + sizeof(TString*) * p->sizeupvalues;
+
+    fprintf(f, "{\"type\":\"proto\",\"cat\":%d,\"size\":%d", p->memcat, int(size));
+
+    if (p->source)
+    {
+        fprintf(f, ",\"source\":\"");
+        dumpstringdata(f, p->source->data, p->source->len);
+        fprintf(f, "\",\"line\":%d", p->abslineinfo ? p->abslineinfo[0] : 0);
+    }
+
+    if (p->sizek)
+    {
+        fprintf(f, ",\"constants\":[");
+        dumprefs(f, p->k, p->sizek);
+        fprintf(f, "]");
+    }
+
+    if (p->sizep)
+    {
+        fprintf(f, ",\"protos\":[");
+        for (int i = 0; i < p->sizep; ++i)
+        {
+            if (i != 0)
+                fputc(',', f);
+            dumpref(f, obj2gco(p->p[i]));
+        }
+        fprintf(f, "]");
+    }
+
+    fprintf(f, "}");
+}
+
+static void dumpupval(FILE* f, UpVal* uv)
+{
+    fprintf(f, "{\"type\":\"upvalue\",\"cat\":%d,\"size\":%d", uv->memcat, int(sizeof(UpVal)));
+
+    if (iscollectable(uv->v))
+    {
+        fprintf(f, ",\"object\":");
+        dumpref(f, gcvalue(uv->v));
+    }
+    fprintf(f, "}");
+}
+
+static void dumpobj(FILE* f, GCObject* o)
+{
+    switch (o->gch.tt)
+    {
+    case LUA_TSTRING:
+        return dumpstring(f, gco2ts(o));
+
+    case LUA_TTABLE:
+        return dumptable(f, gco2h(o));
+
+    case LUA_TFUNCTION:
+        return dumpclosure(f, gco2cl(o));
+
+    case LUA_TUSERDATA:
+        return dumpudata(f, gco2u(o));
+
+    case LUA_TTHREAD:
+        return dumpthread(f, gco2th(o));
+
+    case LUA_TPROTO:
+        return dumpproto(f, gco2p(o));
+
+    case LUA_TUPVAL:
+        return dumpupval(f, gco2uv(o));
+
+    default:
+        LUAU_ASSERT(0);
+    }
+}
+
+static void dumplist(FILE* f, GCObject* o)
+{
+    while (o)
+    {
+        dumpref(f, o);
+        fputc(':', f);
+        dumpobj(f, o);
+        fputc(',', f);
+        fputc('\n', f);
+
+        // thread has additional list containing collectable objects that are not present in rootgc
+        if (o->gch.tt == LUA_TTHREAD)
+            dumplist(f, gco2th(o)->openupval);
+
+        o = o->gch.next;
+    }
+}
+
+void luaC_dump(lua_State* L, void* file, const char* (*categoryName)(lua_State* L, uint8_t memcat))
+{
+    global_State* g = L->global;
+    FILE* f = static_cast<FILE*>(file);
+
+    fprintf(f, "{\"objects\":{\n");
+    dumplist(f, g->rootgc);
+    dumplist(f, g->strbufgc);
+    for (int i = 0; i < g->strt.size; ++i)
+        dumplist(f, g->strt.hash[i]);
+
+    fprintf(f, "\"0\":{\"type\":\"userdata\",\"cat\":0,\"size\":0}\n"); // to avoid issues with trailing ,
+    fprintf(f, "},\"roots\":{\n");
+    fprintf(f, "\"mainthread\":");
+    dumpref(f, obj2gco(g->mainthread));
+    fprintf(f, ",\"registry\":");
+    dumpref(f, gcvalue(&g->registry));
+
+    fprintf(f, "},\"stats\":{\n");
+
+    fprintf(f, "\"size\":%d,\n", int(g->totalbytes));
+
+    fprintf(f, "\"categories\":{\n");
+    for (int i = 0; i < LUA_MEMORY_CATEGORIES; i++)
+    {
+        if (size_t bytes = g->memcatbytes[i])
+        {
+            if (categoryName)
+                fprintf(f, "\"%d\":{\"name\":\"%s\", \"size\":%d},\n", i, categoryName(L, i), int(bytes));
+            else
+                fprintf(f, "\"%d\":{\"size\":%d},\n", i, int(bytes));
+        }
+    }
+    fprintf(f, "\"none\":{}\n"); // to avoid issues with trailing ,
+    fprintf(f, "}\n");
+    fprintf(f, "}}\n");
+}

VM/src/linit.cpp

@@ -17,7 +17,7 @@ static const luaL_Reg lualibs[] = {
     {NULL, NULL},
 };
 
-LUALIB_API void luaL_openlibs(lua_State* L)
+void luaL_openlibs(lua_State* L)
 {
     const luaL_Reg* lib = lualibs;
     for (; lib->func; lib++)
@@ -28,7 +28,7 @@ LUALIB_API void luaL_openlibs(lua_State* L)
     }
 }
 
-LUALIB_API void luaL_sandbox(lua_State* L)
+void luaL_sandbox(lua_State* L)
 {
     // set all libraries to read-only
     lua_pushnil(L);
@@ -44,14 +44,14 @@ LUALIB_API void luaL_sandbox(lua_State* L)
     lua_pushliteral(L, "");
     lua_getmetatable(L, -1);
     lua_setreadonly(L, -1, true);
-    lua_pop(L, 1);
+    lua_pop(L, 2);
 
     // set globals to readonly and activate safeenv since the env is immutable
     lua_setreadonly(L, LUA_GLOBALSINDEX, true);
     lua_setsafeenv(L, LUA_GLOBALSINDEX, true);
 }
 
-LUALIB_API void luaL_sandboxthread(lua_State* L)
+void luaL_sandboxthread(lua_State* L)
 {
     // create new global table that proxies reads to original table
     lua_newtable(L);
@@ -81,7 +81,7 @@ static void* l_alloc(lua_State* L, void* ud, void* ptr, size_t osize, size_t nsi
         return realloc(ptr, nsize);
 }
 
-LUALIB_API lua_State* luaL_newstate(void)
+lua_State* luaL_newstate(void)
 {
     return lua_newstate(l_alloc, NULL);
 }

VM/src/lmathlib.cpp

@@ -385,8 +385,7 @@ static int math_sign(lua_State* L)
 
 static int math_round(lua_State* L)
 {
-    double v = luaL_checknumber(L, 1);
+    lua_pushnumber(L, round(luaL_checknumber(L, 1)));
-    lua_pushnumber(L, round(v));
     return 1;
 }
 
@@ -429,7 +428,7 @@ static const luaL_Reg mathlib[] = {
 /*
 ** Open math library
 */
-LUALIB_API int luaopen_math(lua_State* L)
+int luaopen_math(lua_State* L)
 {
     uint64_t seed = uintptr_t(L);
     seed ^= time(NULL);

VM/src/lmem.cpp

@@ -33,11 +33,17 @@
 #define ABISWITCH(x64, ms32, gcc32) (sizeof(void*) == 8 ? x64 : ms32)
 #endif
 
+#if LUA_VECTOR_SIZE == 4
+static_assert(sizeof(TValue) == ABISWITCH(24, 24, 24), "size mismatch for value");
+static_assert(sizeof(LuaNode) == ABISWITCH(48, 48, 48), "size mismatch for table entry");
+#else
 static_assert(sizeof(TValue) == ABISWITCH(16, 16, 16), "size mismatch for value");
+static_assert(sizeof(LuaNode) == ABISWITCH(32, 32, 32), "size mismatch for table entry");
+#endif
+
 static_assert(offsetof(TString, data) == ABISWITCH(24, 20, 20), "size mismatch for string header");
 static_assert(offsetof(Udata, data) == ABISWITCH(24, 16, 16), "size mismatch for userdata header");
 static_assert(sizeof(Table) == ABISWITCH(56, 36, 36), "size mismatch for table header");
-static_assert(sizeof(LuaNode) == ABISWITCH(32, 32, 32), "size mismatch for table entry");
 
 const size_t kSizeClasses = LUA_SIZECLASSES;
 const size_t kMaxSmallSize = 512;

VM/src/lnumutils.h

@@ -18,12 +18,20 @@
 
 inline bool luai_veceq(const float* a, const float* b)
 {
+#if LUA_VECTOR_SIZE == 4
+    return a[0] == b[0] && a[1] == b[1] && a[2] == b[2] && a[3] == b[3];
+#else
     return a[0] == b[0] && a[1] == b[1] && a[2] == b[2];
+#endif
 }
 
 inline bool luai_vecisnan(const float* a)
 {
+#if LUA_VECTOR_SIZE == 4
+    return a[0] != a[0] || a[1] != a[1] || a[2] != a[2] || a[3] != a[3];
+#else
     return a[0] != a[0] || a[1] != a[1] || a[2] != a[2];
+#endif
 }
 
 LUAU_FASTMATH_BEGIN

VM/src/lobject.cpp

@@ -15,7 +15,7 @@
 
 
 
-const TValue luaO_nilobject_ = {{NULL}, LUA_TNIL};
+const TValue luaO_nilobject_ = {{NULL}, {0}, LUA_TNIL};
 
 int luaO_log2(unsigned int x)
 {

VM/src/lobject.h

@@ -47,7 +47,7 @@ typedef union
 typedef struct lua_TValue
 {
     Value value;
-    int extra;
+    int extra[LUA_EXTRA_SIZE];
     int tt;
 } TValue;
 
@@ -105,7 +105,19 @@ typedef struct lua_TValue
         i_o->tt = LUA_TNUMBER; \
     }
 
-#define setvvalue(obj, x, y, z) \
+#if LUA_VECTOR_SIZE == 4
+#define setvvalue(obj, x, y, z, w) \
+    { \
+        TValue* i_o = (obj); \
+        float* i_v = i_o->value.v; \
+        i_v[0] = (x); \
+        i_v[1] = (y); \
+        i_v[2] = (z); \
+        i_v[3] = (w); \
+        i_o->tt = LUA_TVECTOR; \
+    }
+#else
+#define setvvalue(obj, x, y, z, w) \
     { \
         TValue* i_o = (obj); \
         float* i_v = i_o->value.v; \
@@ -114,6 +126,7 @@ typedef struct lua_TValue
         i_v[2] = (z); \
         i_o->tt = LUA_TVECTOR; \
     }
+#endif
 
 #define setpvalue(obj, x) \
     { \
@@ -364,7 +377,7 @@ typedef struct Closure
 typedef struct TKey
 {
     ::Value value;
-    int extra;
+    int extra[LUA_EXTRA_SIZE];
     unsigned tt : 4;
     int next : 28; /* for chaining */
 } TKey;
@@ -381,7 +394,7 @@ typedef struct LuaNode
         LuaNode* n_ = (node); \
         const TValue* i_o = (obj); \
         n_->key.value = i_o->value; \
-        n_->key.extra = i_o->extra; \
+        memcpy(n_->key.extra, i_o->extra, sizeof(n_->key.extra)); \
         n_->key.tt = i_o->tt; \
         checkliveness(L->global, i_o); \
     }
@@ -392,7 +405,7 @@ typedef struct LuaNode
         TValue* i_o = (obj); \
         const LuaNode* n_ = (node); \
         i_o->value = n_->key.value; \
-        i_o->extra = n_->key.extra; \
+        memcpy(i_o->extra, n_->key.extra, sizeof(i_o->extra)); \
         i_o->tt = n_->key.tt; \
         checkliveness(L->global, i_o); \
     }

VM/src/loslib.cpp

@@ -186,7 +186,7 @@ static const luaL_Reg syslib[] = {
     {NULL, NULL},
 };
 
-LUALIB_API int luaopen_os(lua_State* L)
+int luaopen_os(lua_State* L)
 {
     luaL_register(L, LUA_OSLIBNAME, syslib);
     return 1;

VM/src/lstrlib.cpp

@@ -1657,7 +1657,7 @@ static void createmetatable(lua_State* L)
 /*
 ** Open string library
 */
-LUALIB_API int luaopen_string(lua_State* L)
+int luaopen_string(lua_State* L)
 {
     luaL_register(L, LUA_STRLIBNAME, strlib);
     createmetatable(L);

VM/src/ltable.cpp

@@ -31,18 +31,19 @@ LUAU_FASTFLAGVARIABLE(LuauArrayBoundary, false)
 #define MAXSIZE (1 << MAXBITS)
 
 static_assert(offsetof(LuaNode, val) == 0, "Unexpected Node memory layout, pointer cast in gval2slot is incorrect");
+
 // TKey is bitpacked for memory efficiency so we need to validate bit counts for worst case
-static_assert(TKey{{NULL}, 0, LUA_TDEADKEY, 0}.tt == LUA_TDEADKEY, "not enough bits for tt");
+static_assert(TKey{{NULL}, {0}, LUA_TDEADKEY, 0}.tt == LUA_TDEADKEY, "not enough bits for tt");
-static_assert(TKey{{NULL}, 0, LUA_TNIL, MAXSIZE - 1}.next == MAXSIZE - 1, "not enough bits for next");
+static_assert(TKey{{NULL}, {0}, LUA_TNIL, MAXSIZE - 1}.next == MAXSIZE - 1, "not enough bits for next");
-static_assert(TKey{{NULL}, 0, LUA_TNIL, -(MAXSIZE - 1)}.next == -(MAXSIZE - 1), "not enough bits for next");
+static_assert(TKey{{NULL}, {0}, LUA_TNIL, -(MAXSIZE - 1)}.next == -(MAXSIZE - 1), "not enough bits for next");
 
 // reset cache of absent metamethods, cache is updated in luaT_gettm
 #define invalidateTMcache(t) t->flags = 0
 
 // empty hash data points to dummynode so that we can always dereference it
 const LuaNode luaH_dummynode = {
-    {{NULL}, 0, LUA_TNIL},   /* value */
+    {{NULL}, {0}, LUA_TNIL},   /* value */
-    {{NULL}, 0, LUA_TNIL, 0} /* key */
+    {{NULL}, {0}, LUA_TNIL, 0} /* key */
 };
 
 #define dummynode (&luaH_dummynode)
@@ -96,7 +97,7 @@ static LuaNode* hashnum(const Table* t, double n)
 
 static LuaNode* hashvec(const Table* t, const float* v)
 {
-    unsigned int i[3];
+    unsigned int i[LUA_VECTOR_SIZE];
     memcpy(i, v, sizeof(i));
 
     // convert -0 to 0 to make sure they hash to the same value
@@ -112,6 +113,12 @@ static LuaNode* hashvec(const Table* t, const float* v)
     // Optimized Spatial Hashing for Collision Detection of Deformable Objects
     unsigned int h = (i[0] * 73856093) ^ (i[1] * 19349663) ^ (i[2] * 83492791);
 
+#if LUA_VECTOR_SIZE == 4
+    i[3] = (i[3] == 0x8000000) ? 0 : i[3];
+    i[3] ^= i[3] >> 17;
+    h ^= i[3] * 39916801;
+#endif
+
     return hashpow2(t, h);
 }
 

VM/src/ltablib.cpp

@@ -527,7 +527,7 @@ static const luaL_Reg tab_funcs[] = {
     {NULL, NULL},
 };
 
-LUALIB_API int luaopen_table(lua_State* L)
+int luaopen_table(lua_State* L)
 {
     luaL_register(L, LUA_TABLIBNAME, tab_funcs);
 

VM/src/lutf8lib.cpp

@@ -283,7 +283,7 @@ static const luaL_Reg funcs[] = {
     {NULL, NULL},
 };
 
-LUALIB_API int luaopen_utf8(lua_State* L)
+int luaopen_utf8(lua_State* L)
 {
     luaL_register(L, LUA_UTF8LIBNAME, funcs);
 

VM/src/lvmexecute.cpp

@@ -601,7 +601,13 @@ static void luau_execute(lua_State* L)
                         const char* name = getstr(tsvalue(kv));
                         int ic = (name[0] | ' ') - 'x';
 
-                        if (unsigned(ic) < 3 && name[1] == '\0')
+#if LUA_VECTOR_SIZE == 4
+                        // 'w' is before 'x' in ascii, so ic is -1 when indexing with 'w'
+                        if (ic == -1)
+                            ic = 3;
+#endif
+
+                        if (unsigned(ic) < LUA_VECTOR_SIZE && name[1] == '\0')
                         {
                             setnvalue(ra, rb->value.v[ic]);
                             VM_NEXT();
@@ -1526,7 +1532,7 @@ static void luau_execute(lua_State* L)
                 {
                     const float* vb = rb->value.v;
                     const float* vc = rc->value.v;
-                    setvvalue(ra, vb[0] + vc[0], vb[1] + vc[1], vb[2] + vc[2]);
+                    setvvalue(ra, vb[0] + vc[0], vb[1] + vc[1], vb[2] + vc[2], vb[3] + vc[3]);
                     VM_NEXT();
                 }
                 else
@@ -1572,7 +1578,7 @@ static void luau_execute(lua_State* L)
                 {
                     const float* vb = rb->value.v;
                     const float* vc = rc->value.v;
-                    setvvalue(ra, vb[0] - vc[0], vb[1] - vc[1], vb[2] - vc[2]);
+                    setvvalue(ra, vb[0] - vc[0], vb[1] - vc[1], vb[2] - vc[2], vb[3] - vc[3]);
                     VM_NEXT();
                 }
                 else
@@ -1618,21 +1624,21 @@ static void luau_execute(lua_State* L)
                 {
                     const float* vb = rb->value.v;
                     float vc = cast_to(float, nvalue(rc));
-                    setvvalue(ra, vb[0] * vc, vb[1] * vc, vb[2] * vc);
+                    setvvalue(ra, vb[0] * vc, vb[1] * vc, vb[2] * vc, vb[3] * vc);
                     VM_NEXT();
                 }
                 else if (ttisvector(rb) && ttisvector(rc))
                 {
                     const float* vb = rb->value.v;
                     const float* vc = rc->value.v;
-                    setvvalue(ra, vb[0] * vc[0], vb[1] * vc[1], vb[2] * vc[2]);
+                    setvvalue(ra, vb[0] * vc[0], vb[1] * vc[1], vb[2] * vc[2], vb[3] * vc[3]);
                     VM_NEXT();
                 }
                 else if (ttisnumber(rb) && ttisvector(rc))
                 {
                     float vb = cast_to(float, nvalue(rb));
                     const float* vc = rc->value.v;
-                    setvvalue(ra, vb * vc[0], vb * vc[1], vb * vc[2]);
+                    setvvalue(ra, vb * vc[0], vb * vc[1], vb * vc[2], vb * vc[3]);
                     VM_NEXT();
                 }
                 else
@@ -1679,21 +1685,21 @@ static void luau_execute(lua_State* L)
                 {
                     const float* vb = rb->value.v;
                     float vc = cast_to(float, nvalue(rc));
-                    setvvalue(ra, vb[0] / vc, vb[1] / vc, vb[2] / vc);
+                    setvvalue(ra, vb[0] / vc, vb[1] / vc, vb[2] / vc, vb[3] / vc);
                     VM_NEXT();
                 }
                 else if (ttisvector(rb) && ttisvector(rc))
                 {
                     const float* vb = rb->value.v;
                     const float* vc = rc->value.v;
-                    setvvalue(ra, vb[0] / vc[0], vb[1] / vc[1], vb[2] / vc[2]);
+                    setvvalue(ra, vb[0] / vc[0], vb[1] / vc[1], vb[2] / vc[2], vb[3] / vc[3]);
                     VM_NEXT();
                 }
                 else if (ttisnumber(rb) && ttisvector(rc))
                 {
                     float vb = cast_to(float, nvalue(rb));
                     const float* vc = rc->value.v;
-                    setvvalue(ra, vb / vc[0], vb / vc[1], vb / vc[2]);
+                    setvvalue(ra, vb / vc[0], vb / vc[1], vb / vc[2], vb / vc[3]);
                     VM_NEXT();
                 }
                 else
@@ -1826,7 +1832,7 @@ static void luau_execute(lua_State* L)
                 {
                     const float* vb = rb->value.v;
                     float vc = cast_to(float, nvalue(kv));
-                    setvvalue(ra, vb[0] * vc, vb[1] * vc, vb[2] * vc);
+                    setvvalue(ra, vb[0] * vc, vb[1] * vc, vb[2] * vc, vb[3] * vc);
                     VM_NEXT();
                 }
                 else
@@ -1872,7 +1878,7 @@ static void luau_execute(lua_State* L)
                 {
                     const float* vb = rb->value.v;
                     float vc = cast_to(float, nvalue(kv));
-                    setvvalue(ra, vb[0] / vc, vb[1] / vc, vb[2] / vc);
+                    setvvalue(ra, vb[0] / vc, vb[1] / vc, vb[2] / vc, vb[3] / vc);
                     VM_NEXT();
                 }
                 else
@@ -2037,7 +2043,7 @@ static void luau_execute(lua_State* L)
                 else if (ttisvector(rb))
                 {
                     const float* vb = rb->value.v;
-                    setvvalue(ra, -vb[0], -vb[1], -vb[2]);
+                    setvvalue(ra, -vb[0], -vb[1], -vb[2], -vb[3]);
                     VM_NEXT();
                 }
                 else

VM/src/lvmload.cpp

@@ -9,6 +9,7 @@
 #include "lgc.h"
 #include "lmem.h"
 #include "lbytecode.h"
+#include "lapi.h"
 
 #include <string.h>
 
@@ -162,9 +163,8 @@ int luau_load(lua_State* L, const char* chunkname, const char* data, size_t size
     size_t GCthreshold = L->global->GCthreshold;
     L->global->GCthreshold = SIZE_MAX;
 
-    // env is 0 for current environment and a stack relative index otherwise
+    // env is 0 for current environment and a stack index otherwise
-    LUAU_ASSERT(env <= 0 && L->top - L->base >= -env);
+    Table* envt = (env == 0) ? hvalue(gt(L)) : hvalue(luaA_toobject(L, env));
-    Table* envt = (env == 0) ? hvalue(gt(L)) : hvalue(L->top + env);
 
     TString* source = luaS_new(L, chunkname);
 

VM/src/lvmutils.cpp

@@ -401,19 +401,19 @@ void luaV_doarith(lua_State* L, StkId ra, const TValue* rb, const TValue* rc, TM
             switch (op)
             {
             case TM_ADD:
-                setvvalue(ra, vb[0] + vc[0], vb[1] + vc[1], vb[2] + vc[2]);
+                setvvalue(ra, vb[0] + vc[0], vb[1] + vc[1], vb[2] + vc[2], vb[3] + vc[3]);
                 return;
             case TM_SUB:
-                setvvalue(ra, vb[0] - vc[0], vb[1] - vc[1], vb[2] - vc[2]);
+                setvvalue(ra, vb[0] - vc[0], vb[1] - vc[1], vb[2] - vc[2], vb[3] - vc[3]);
                 return;
             case TM_MUL:
-                setvvalue(ra, vb[0] * vc[0], vb[1] * vc[1], vb[2] * vc[2]);
+                setvvalue(ra, vb[0] * vc[0], vb[1] * vc[1], vb[2] * vc[2], vb[3] * vc[3]);
                 return;
             case TM_DIV:
-                setvvalue(ra, vb[0] / vc[0], vb[1] / vc[1], vb[2] / vc[2]);
+                setvvalue(ra, vb[0] / vc[0], vb[1] / vc[1], vb[2] / vc[2], vb[3] / vc[3]);
                 return;
             case TM_UNM:
-                setvvalue(ra, -vb[0], -vb[1], -vb[2]);
+                setvvalue(ra, -vb[0], -vb[1], -vb[2], -vb[3]);
                 return;
             default:
                 break;
@@ -430,10 +430,10 @@ void luaV_doarith(lua_State* L, StkId ra, const TValue* rb, const TValue* rc, TM
                 switch (op)
                 {
                 case TM_MUL:
-                    setvvalue(ra, vb[0] * nc, vb[1] * nc, vb[2] * nc);
+                    setvvalue(ra, vb[0] * nc, vb[1] * nc, vb[2] * nc, vb[3] * nc);
                     return;
                 case TM_DIV:
-                    setvvalue(ra, vb[0] / nc, vb[1] / nc, vb[2] / nc);
+                    setvvalue(ra, vb[0] / nc, vb[1] / nc, vb[2] / nc, vb[3] / nc);
                     return;
                 default:
                     break;
@@ -451,10 +451,10 @@ void luaV_doarith(lua_State* L, StkId ra, const TValue* rb, const TValue* rc, TM
                 switch (op)
                 {
                 case TM_MUL:
-                    setvvalue(ra, nb * vc[0], nb * vc[1], nb * vc[2]);
+                    setvvalue(ra, nb * vc[0], nb * vc[1], nb * vc[2], nb * vc[3]);
                     return;
                 case TM_DIV:
-                    setvvalue(ra, nb / vc[0], nb / vc[1], nb / vc[2]);
+                    setvvalue(ra, nb / vc[0], nb / vc[1], nb / vc[2], nb / vc[3]);
                     return;
                 default:
                     break;

bench/gc/test_LB_mandel.lua

@@ -88,7 +88,7 @@ for i=1,N do
   local y=ymin+(j-1)*dy
   S = S + level(x,y)
  end
- -- if i % 10 == 0 then print(collectgarbage"count") end
+ -- if i % 10 == 0 then print(collectgarbage("count")) end
 end
 print(S)
 

bench/tests/shootout/mandel.lua

@@ -88,7 +88,7 @@ for i=1,N do
   local y=ymin+(j-1)*dy
   S = S + level(x,y)
  end
- -- if i % 10 == 0 then print(collectgarbage"count") end
+ -- if i % 10 == 0 then print(collectgarbage("count")) end
 end
 print(S)
 

bench/tests/shootout/qt.lua

@@ -275,7 +275,7 @@ local function memory(s)
 	local t=os.clock()
 	--local dt=string.format("%f",t-t0)
 	local dt=t-t0
-	--io.stdout:write(s,"\t",dt," sec\t",t," sec\t",math.floor(collectgarbage"count"/1024),"M\n")
+	--io.stdout:write(s,"\t",dt," sec\t",t," sec\t",math.floor(collectgarbage("count")/1024),"M\n")
 	t0=t
 end
 
@@ -286,7 +286,7 @@ local function do_(f,s)
 end
 
 local function julia(l,a,b)
-memory"begin"
+memory("begin")
 	cx=a	cy=b
 	root=newcell()
 	exterior=newcell()	exterior.color=white
@@ -297,14 +297,14 @@ memory"begin"
 		do_(update,"update")
 		repeat
 			N=0 color(root,Rxmin,Rxmax,Rymin,Rymax) --print("color",N)
-		until N==0 memory"color"
+		until N==0 memory("color")
 		repeat
 			N=0 prewhite(root,Rxmin,Rxmax,Rymin,Rymax) --print("prewhite",N)
-		until N==0 memory"prewhite"
+		until N==0 memory("prewhite")
 		do_(recolor,"recolor")
 		do_(colorup,"colorup")		--print("colorup",N)
 		local g,b=do_(area,"area")	--print("area",g,b,g+b)
-		show(i) memory"output"
+		show(i) memory("output")
 	--print("edges",nE)
 	end
 end

fuzz/proto.cpp

@@ -23,9 +23,11 @@ const bool kFuzzCompiler = true;
 const bool kFuzzLinter = true;
 const bool kFuzzTypeck = true;
 const bool kFuzzVM = true;
-const bool kFuzzTypes = true;
 const bool kFuzzTranspile = true;
 
+// Should we generate type annotations?
+const bool kFuzzTypes = true;
+
 static_assert(!(kFuzzVM && !kFuzzCompiler), "VM requires the compiler!");
 
 std::string protoprint(const luau::StatBlock& stat, bool types);

tests/AstQuery.test.cpp

@@ -78,3 +78,26 @@ TEST_CASE_FIXTURE(DocumentationSymbolFixture, "overloaded_fn")
 }
 
 TEST_SUITE_END();
+
+TEST_SUITE_BEGIN("AstQuery");
+
+TEST_CASE_FIXTURE(Fixture, "last_argument_function_call_type")
+{
+    ScopedFastFlag luauTailArgumentTypeInfo{"LuauTailArgumentTypeInfo", true};
+
+    check(R"(
+local function foo() return 2 end
+local function bar(a: number) return -a end
+bar(foo())
+    )");
+
+    auto oty = findTypeAtPosition(Position(3, 7));
+    REQUIRE(oty);
+    CHECK_EQ("number", toString(*oty));
+
+    auto expectedOty = findExpectedTypeAtPosition(Position(3, 7));
+    REQUIRE(expectedOty);
+    CHECK_EQ("number", toString(*expectedOty));
+}
+
+TEST_SUITE_END();

tests/Autocomplete.test.cpp

@@ -1935,6 +1935,39 @@ return target(b@1
     CHECK(ac.entryMap["bar2"].typeCorrect == TypeCorrectKind::None);
 }
 
+TEST_CASE_FIXTURE(ACFixture, "function_in_assignment_has_parentheses")
+{
+    ScopedFastFlag luauAutocompleteAvoidMutation("LuauAutocompleteAvoidMutation", true);
+    ScopedFastFlag luauAutocompletePreferToCallFunctions("LuauAutocompletePreferToCallFunctions", true);
+
+    check(R"(
+local function bar(a: number) return -a end
+local abc = b@1
+    )");
+
+    auto ac = autocomplete('1');
+
+    CHECK(ac.entryMap.count("bar"));
+    CHECK(ac.entryMap["bar"].parens == ParenthesesRecommendation::CursorInside);
+}
+
+TEST_CASE_FIXTURE(ACFixture, "function_result_passed_to_function_has_parentheses")
+{
+    ScopedFastFlag luauAutocompleteAvoidMutation("LuauAutocompleteAvoidMutation", true);
+    ScopedFastFlag luauAutocompletePreferToCallFunctions("LuauAutocompletePreferToCallFunctions", true);
+
+    check(R"(
+local function foo() return 1 end
+local function bar(a: number) return -a end
+local abc = bar(@1) 
+    )");
+
+    auto ac = autocomplete('1');
+
+    CHECK(ac.entryMap.count("foo"));
+    CHECK(ac.entryMap["foo"].parens == ParenthesesRecommendation::CursorAfter);
+}
+
 TEST_CASE_FIXTURE(ACFixture, "type_correct_sealed_table")
 {
     check(R"(
@@ -2210,8 +2243,6 @@ TEST_CASE_FIXTURE(ACFixture, "autocompleteSource")
 
 TEST_CASE_FIXTURE(ACFixture, "autocompleteSource_require")
 {
-    ScopedFastFlag luauResolveModuleNameWithoutACurrentModule("LuauResolveModuleNameWithoutACurrentModule", true);
-
     std::string_view source = R"(
         local a = require(w -- Line 1
         --                 | Column 27
@@ -2287,8 +2318,6 @@ until
 
 TEST_CASE_FIXTURE(ACFixture, "if_then_else_elseif_completions")
 {
-    ScopedFastFlag sff{"ElseElseIfCompletionImprovements", true};
-
     check(R"(
 local elsewhere = false
 
@@ -2585,9 +2614,6 @@ a = if temp then even elseif true then temp else e@9
 
 TEST_CASE_FIXTURE(ACFixture, "autocomplete_explicit_type_pack")
 {
-    ScopedFastFlag luauTypeAliasPacks("LuauTypeAliasPacks", true);
-    ScopedFastFlag luauParseTypePackTypeParameters("LuauParseTypePackTypeParameters", true);
-
     check(R"(
 type A<T...> = () -> T...
 local a: A<(number, s@1>

tests/Compiler.test.cpp

@@ -1057,6 +1057,18 @@ RETURN R0 1
     CHECK_EQ("\n" + compileFunction0("return if false then 10 else 20"), R"(
 LOADN R0 20
 RETURN R0 1
+)");
+
+    // codegen for a true constant condition with non-constant expressions
+    CHECK_EQ("\n" + compileFunction0("return if true then {} else error()"), R"(
+NEWTABLE R0 0 0
+RETURN R0 1
+)");
+
+    // codegen for a false constant condition with non-constant expressions
+    CHECK_EQ("\n" + compileFunction0("return if false then error() else {}"), R"(
+NEWTABLE R0 0 0
+RETURN R0 1
 )");
 
     // codegen for a false (in this case 'nil') constant condition
@@ -2360,6 +2372,58 @@ Foo:Bar(
 )");
 }
 
+TEST_CASE("DebugLineInfoCallChain")
+{
+    Luau::BytecodeBuilder bcb;
+    bcb.setDumpFlags(Luau::BytecodeBuilder::Dump_Code | Luau::BytecodeBuilder::Dump_Lines);
+    Luau::compileOrThrow(bcb, R"(
+local Foo = ...
+
+Foo
+:Bar(1)
+:Baz(2)
+.Qux(3)
+)");
+
+    CHECK_EQ("\n" + bcb.dumpFunction(0), R"(
+2: GETVARARGS R0 1
+5: LOADN R4 1
+5: NAMECALL R2 R0 K0
+5: CALL R2 2 1
+6: LOADN R4 2
+6: NAMECALL R2 R2 K1
+6: CALL R2 2 1
+7: GETTABLEKS R1 R2 K2
+7: LOADN R2 3
+7: CALL R1 1 0
+8: RETURN R0 0
+)");
+}
+
+TEST_CASE("DebugLineInfoFastCall")
+{
+    Luau::BytecodeBuilder bcb;
+    bcb.setDumpFlags(Luau::BytecodeBuilder::Dump_Code | Luau::BytecodeBuilder::Dump_Lines);
+    Luau::compileOrThrow(bcb, R"(
+local Foo, Bar = ...
+
+return
+    math.max(
+        Foo,
+        Bar)
+)");
+
+    CHECK_EQ("\n" + bcb.dumpFunction(0), R"(
+2: GETVARARGS R0 2
+5: FASTCALL2 18 R0 R1 +5
+5: MOVE R3 R0
+5: MOVE R4 R1
+5: GETIMPORT R2 2
+5: CALL R2 2 -1
+5: RETURN R2 -1
+)");
+}
+
 TEST_CASE("DebugSource")
 {
     const char* source = R"(
@@ -3742,4 +3806,108 @@ RETURN R0 0
 )");
 }
 
+TEST_CASE("ConstantsNoFolding")
+{
+    const char* source = "return nil, true, 42, 'hello'";
+
+    Luau::BytecodeBuilder bcb;
+    bcb.setDumpFlags(Luau::BytecodeBuilder::Dump_Code);
+    Luau::CompileOptions options;
+    options.optimizationLevel = 0;
+    Luau::compileOrThrow(bcb, source, options);
+
+    CHECK_EQ("\n" + bcb.dumpFunction(0), R"(
+LOADNIL R0
+LOADB R1 1
+LOADK R2 K0
+LOADK R3 K1
+RETURN R0 4
+)");
+}
+
+TEST_CASE("VectorFastCall")
+{
+    const char* source = "return Vector3.new(1, 2, 3)";
+
+    Luau::BytecodeBuilder bcb;
+    bcb.setDumpFlags(Luau::BytecodeBuilder::Dump_Code);
+    Luau::CompileOptions options;
+    options.vectorLib = "Vector3";
+    options.vectorCtor = "new";
+    Luau::compileOrThrow(bcb, source, options);
+
+    CHECK_EQ("\n" + bcb.dumpFunction(0), R"(
+LOADN R1 1
+LOADN R2 2
+LOADN R3 3
+FASTCALL 54 +2
+GETIMPORT R0 2
+CALL R0 3 -1
+RETURN R0 -1
+)");
+}
+
+TEST_CASE("TypeAssertion")
+{
+    // validate that type assertions work with the compiler and that the code inside type assertion isn't evaluated
+    CHECK_EQ("\n" + compileFunction0(R"(
+print(foo() :: typeof(error("compile time")))
+)"),
+        R"(
+GETIMPORT R0 1
+GETIMPORT R1 3
+CALL R1 0 1
+CALL R0 1 0
+RETURN R0 0
+)");
+
+    // note that above, foo() is treated as single-arg function; removing type assertion changes the bytecode
+    CHECK_EQ("\n" + compileFunction0(R"(
+print(foo())
+)"),
+        R"(
+GETIMPORT R0 1
+GETIMPORT R1 3
+CALL R1 0 -1
+CALL R0 -1 0
+RETURN R0 0
+)");
+}
+
+TEST_CASE("Arithmetics")
+{
+    // basic arithmetics codegen with non-constants
+    CHECK_EQ("\n" + compileFunction0(R"(
+local a, b = ...
+return a + b, a - b, a / b, a * b, a % b, a ^ b
+)"),
+        R"(
+GETVARARGS R0 2
+ADD R2 R0 R1
+SUB R3 R0 R1
+DIV R4 R0 R1
+MUL R5 R0 R1
+MOD R6 R0 R1
+POW R7 R0 R1
+RETURN R2 6
+)");
+
+    // basic arithmetics codegen with constants on the right side
+    // note that we don't simplify these expressions as we don't know the type of a
+    CHECK_EQ("\n" + compileFunction0(R"(
+local a = ...
+return a + 1, a - 1, a / 1, a * 1, a % 1, a ^ 1
+)"),
+        R"(
+GETVARARGS R0 1
+ADDK R1 R0 K0
+SUBK R2 R0 K0
+DIVK R3 R0 K0
+MULK R4 R0 K0
+MODK R5 R0 K0
+POWK R6 R0 K0
+RETURN R1 6
+)");
+}
+
 TEST_SUITE_END();

tests/Conformance.test.cpp

@@ -67,44 +67,42 @@ static int lua_vector(lua_State* L)
     double y = luaL_checknumber(L, 2);
     double z = luaL_checknumber(L, 3);
 
+#if LUA_VECTOR_SIZE == 4
+    double w = luaL_optnumber(L, 4, 0.0);
+    lua_pushvector(L, float(x), float(y), float(z), float(w));
+#else
     lua_pushvector(L, float(x), float(y), float(z));
+#endif
     return 1;
 }
 
 static int lua_vector_dot(lua_State* L)
 {
-    const float* a = lua_tovector(L, 1);
+    const float* a = luaL_checkvector(L, 1);
-    const float* b = lua_tovector(L, 2);
+    const float* b = luaL_checkvector(L, 2);
 
-    if (a && b)
+    lua_pushnumber(L, a[0] * b[0] + a[1] * b[1] + a[2] * b[2]);
-    {
+    return 1;
-        lua_pushnumber(L, a[0] * b[0] + a[1] * b[1] + a[2] * b[2]);
-        return 1;
-    }
-
-    throw std::runtime_error("invalid arguments to vector:Dot");
 }
 
 static int lua_vector_index(lua_State* L)
 {
+    const float* v = luaL_checkvector(L, 1);
     const char* name = luaL_checkstring(L, 2);
 
-    if (const float* v = lua_tovector(L, 1))
+    if (strcmp(name, "Magnitude") == 0)
     {
-        if (strcmp(name, "Magnitude") == 0)
+        lua_pushnumber(L, sqrtf(v[0] * v[0] + v[1] * v[1] + v[2] * v[2]));
-        {
+        return 1;
-            lua_pushnumber(L, sqrtf(v[0] * v[0] + v[1] * v[1] + v[2] * v[2]));
-            return 1;
-        }
-
-        if (strcmp(name, "Dot") == 0)
-        {
-            lua_pushcfunction(L, lua_vector_dot, "Dot");
-            return 1;
-        }
     }
 
-    throw std::runtime_error(Luau::format("%s is not a valid member of vector", name));
+    if (strcmp(name, "Dot") == 0)
+    {
+        lua_pushcfunction(L, lua_vector_dot, "Dot");
+        return 1;
+    }
+
+    luaL_error(L, "%s is not a valid member of vector", name);
 }
 
 static int lua_vector_namecall(lua_State* L)
@@ -115,7 +113,7 @@ static int lua_vector_namecall(lua_State* L)
             return lua_vector_dot(L);
     }
 
-    throw std::runtime_error(Luau::format("%s is not a valid method of vector", luaL_checkstring(L, 1)));
+    luaL_error(L, "%s is not a valid method of vector", luaL_checkstring(L, 1));
 }
 
 int lua_silence(lua_State* L)
@@ -373,11 +371,17 @@ TEST_CASE("Pack")
 
 TEST_CASE("Vector")
 {
+    ScopedFastFlag sff{"LuauIfElseExpressionBaseSupport", true};
+
     runConformance("vector.lua", [](lua_State* L) {
         lua_pushcfunction(L, lua_vector, "vector");
         lua_setglobal(L, "vector");
 
+#if LUA_VECTOR_SIZE == 4
+        lua_pushvector(L, 0.0f, 0.0f, 0.0f, 0.0f);
+#else
         lua_pushvector(L, 0.0f, 0.0f, 0.0f);
+#endif
         luaL_newmetatable(L, "vector");
 
         lua_pushstring(L, "__index");
@@ -504,6 +508,9 @@ TEST_CASE("Debugger")
             cb->debugbreak = [](lua_State* L, lua_Debug* ar) {
                 breakhits++;
 
+                // make sure we can trace the stack for every breakpoint we hit
+                lua_debugtrace(L);
+
                 // for every breakpoint, we break on the first invocation and continue on second
                 // this allows us to easily step off breakpoints
                 // (real implementaiton may require singlestepping)
@@ -524,7 +531,7 @@ TEST_CASE("Debugger")
                 L,
                 [](lua_State* L) -> int {
                     int line = luaL_checkinteger(L, 1);
-                    bool enabled = lua_isboolean(L, 2) ? lua_toboolean(L, 2) : true;
+                    bool enabled = luaL_optboolean(L, 2, true);
 
                     lua_Debug ar = {};
                     lua_getinfo(L, 1, "f", &ar);
@@ -699,21 +706,52 @@ TEST_CASE("ApiFunctionCalls")
     StateRef globalState = runConformance("apicalls.lua");
     lua_State* L = globalState.get();
 
-    lua_getfield(L, LUA_GLOBALSINDEX, "add");
+    // lua_call
-    lua_pushnumber(L, 40);
+    {
-    lua_pushnumber(L, 2);
+        lua_getfield(L, LUA_GLOBALSINDEX, "add");
-    lua_call(L, 2, 1);
+        lua_pushnumber(L, 40);
-    CHECK(lua_isnumber(L, -1));
+        lua_pushnumber(L, 2);
-    CHECK(lua_tonumber(L, -1) == 42);
+        lua_call(L, 2, 1);
-    lua_pop(L, 1);
+        CHECK(lua_isnumber(L, -1));
+        CHECK(lua_tonumber(L, -1) == 42);
+        lua_pop(L, 1);
+    }
 
-    lua_getfield(L, LUA_GLOBALSINDEX, "add");
+    // lua_pcall
-    lua_pushnumber(L, 40);
+    {
-    lua_pushnumber(L, 2);
+        lua_getfield(L, LUA_GLOBALSINDEX, "add");
-    lua_pcall(L, 2, 1, 0);
+        lua_pushnumber(L, 40);
-    CHECK(lua_isnumber(L, -1));
+        lua_pushnumber(L, 2);
-    CHECK(lua_tonumber(L, -1) == 42);
+        lua_pcall(L, 2, 1, 0);
-    lua_pop(L, 1);
+        CHECK(lua_isnumber(L, -1));
+        CHECK(lua_tonumber(L, -1) == 42);
+        lua_pop(L, 1);
+    }
+
+    // lua_equal with a sleeping thread wake up
+    {
+        ScopedFastFlag luauActivateBeforeExec("LuauActivateBeforeExec", true);
+
+        lua_State* L2 = lua_newthread(L);
+
+        lua_getfield(L2, LUA_GLOBALSINDEX, "create_with_tm");
+        lua_pushnumber(L2, 42);
+        lua_pcall(L2, 1, 1, 0);
+
+        lua_getfield(L2, LUA_GLOBALSINDEX, "create_with_tm");
+        lua_pushnumber(L2, 42);
+        lua_pcall(L2, 1, 1, 0);
+
+        // Reset GC
+        lua_gc(L2, LUA_GCCOLLECT, 0);
+
+        // Try to mark 'L2' as sleeping
+        // Can't control GC precisely, even in tests
+        lua_gc(L2, LUA_GCSTEP, 8);
+
+        CHECK(lua_equal(L2, -1, -2) == 1);
+        lua_pop(L2, 2);
+    }
 }
 
 static bool endsWith(const std::string& str, const std::string& suffix)
@@ -727,8 +765,6 @@ static bool endsWith(const std::string& str, const std::string& suffix)
 #if !LUA_USE_LONGJMP
 TEST_CASE("ExceptionObject")
 {
-    ScopedFastFlag sff("LuauExceptionMessageFix", true);
-
     struct ExceptionResult
     {
         bool exceptionGenerated;

tests/Fixture.cpp

@@ -19,19 +19,6 @@ static const char* mainModuleName = "MainModule";
 namespace Luau
 {
 
-std::optional<ModuleName> TestFileResolver::fromAstFragment(AstExpr* expr) const
-{
-    auto g = expr->as<AstExprGlobal>();
-    if (!g)
-        return std::nullopt;
-
-    std::string_view value = g->name.value;
-    if (value == "game" || value == "Game" || value == "workspace" || value == "Workspace" || value == "script" || value == "Script")
-        return ModuleName(value);
-
-    return std::nullopt;
-}
-
 std::optional<ModuleInfo> TestFileResolver::resolveModule(const ModuleInfo* context, AstExpr* expr)
 {
     if (AstExprGlobal* g = expr->as<AstExprGlobal>())
@@ -81,24 +68,6 @@ std::optional<ModuleInfo> TestFileResolver::resolveModule(const ModuleInfo* cont
     return std::nullopt;
 }
 
-ModuleName TestFileResolver::concat(const ModuleName& lhs, std::string_view rhs) const
-{
-    return lhs + "/" + ModuleName(rhs);
-}
-
-std::optional<ModuleName> TestFileResolver::getParentModuleName(const ModuleName& name) const
-{
-    std::string_view view = name;
-    const size_t lastSeparatorIndex = view.find_last_of('/');
-
-    if (lastSeparatorIndex != std::string_view::npos)
-    {
-        return ModuleName(view.substr(0, lastSeparatorIndex));
-    }
-
-    return std::nullopt;
-}
-
 std::string TestFileResolver::getHumanReadableModuleName(const ModuleName& name) const
 {
     return name;
@@ -324,6 +293,13 @@ std::optional<TypeId> Fixture::findTypeAtPosition(Position position)
     return Luau::findTypeAtPosition(*module, *sourceModule, position);
 }
 
+std::optional<TypeId> Fixture::findExpectedTypeAtPosition(Position position)
+{
+    ModulePtr module = getMainModule();
+    SourceModule* sourceModule = getMainSourceModule();
+    return Luau::findExpectedTypeAtPosition(*module, *sourceModule, position);
+}
+
 TypeId Fixture::requireTypeAtPosition(Position position)
 {
     auto ty = findTypeAtPosition(position);

tests/Fixture.h

@@ -64,12 +64,8 @@ struct TestFileResolver
         return SourceCode{it->second, sourceType};
     }
 
-    std::optional<ModuleName> fromAstFragment(AstExpr* expr) const override;
     std::optional<ModuleInfo> resolveModule(const ModuleInfo* context, AstExpr* expr) override;
 
-    ModuleName concat(const ModuleName& lhs, std::string_view rhs) const override;
-    std::optional<ModuleName> getParentModuleName(const ModuleName& name) const override;
-
     std::string getHumanReadableModuleName(const ModuleName& name) const override;
 
     std::optional<std::string> getEnvironmentForModule(const ModuleName& name) const override;
@@ -126,6 +122,7 @@ struct Fixture
 
     std::optional<TypeId> findTypeAtPosition(Position position);
     TypeId requireTypeAtPosition(Position position);
+    std::optional<TypeId> findExpectedTypeAtPosition(Position position);
 
     std::optional<TypeId> lookupType(const std::string& name);
     std::optional<TypeId> lookupImportedType(const std::string& moduleAlias, const std::string& name);

tests/Frontend.test.cpp

@@ -46,18 +46,6 @@ NaiveModuleResolver naiveModuleResolver;
 
 struct NaiveFileResolver : NullFileResolver
 {
-    std::optional<ModuleName> fromAstFragment(AstExpr* expr) const override
-    {
-        AstExprGlobal* g = expr->as<AstExprGlobal>();
-        if (g && g->name == "Modules")
-            return "Modules";
-
-        if (g && g->name == "game")
-            return "game";
-
-        return std::nullopt;
-    }
-
     std::optional<ModuleInfo> resolveModule(const ModuleInfo* context, AstExpr* expr) override
     {
         if (AstExprGlobal* g = expr->as<AstExprGlobal>())
@@ -86,11 +74,6 @@ struct NaiveFileResolver : NullFileResolver
 
         return std::nullopt;
     }
-
-    ModuleName concat(const ModuleName& lhs, std::string_view rhs) const override
-    {
-        return lhs + "/" + ModuleName(rhs);
-    }
 };
 
 } // namespace

tests/Linter.test.cpp

@@ -1469,6 +1469,22 @@ _ = true and true or false -- no warning since this is is a common pattern used
     CHECK_EQ(result.warnings[6].location.begin.line + 1, 19);
 }
 
+TEST_CASE_FIXTURE(Fixture, "DuplicateConditionsExpr")
+{
+    LintResult result = lint(R"(
+local correct, opaque = ...
+
+if correct({a = 1, b = 2 * (-2), c = opaque.path['with']("calls")}) then
+elseif correct({a = 1, b = 2 * (-2), c = opaque.path['with']("calls")}) then
+elseif correct({a = 1, b = 2 * (-2), c = opaque.path['with']("calls", false)}) then
+end
+)");
+
+    REQUIRE_EQ(result.warnings.size(), 1);
+    CHECK_EQ(result.warnings[0].text, "Condition has already been checked on line 4");
+    CHECK_EQ(result.warnings[0].location.begin.line + 1, 5);
+}
+
 TEST_CASE_FIXTURE(Fixture, "DuplicateLocal")
 {
     LintResult result = lint(R"(

tests/Module.test.cpp

@@ -44,9 +44,10 @@ TEST_CASE_FIXTURE(Fixture, "dont_clone_persistent_primitive")
 
     SeenTypes seenTypes;
     SeenTypePacks seenTypePacks;
+    CloneState cloneState;
 
     // numberType is persistent.  We leave it as-is.
-    TypeId newNumber = clone(typeChecker.numberType, dest, seenTypes, seenTypePacks);
+    TypeId newNumber = clone(typeChecker.numberType, dest, seenTypes, seenTypePacks, cloneState);
     CHECK_EQ(newNumber, typeChecker.numberType);
 }
 
@@ -56,12 +57,13 @@ TEST_CASE_FIXTURE(Fixture, "deepClone_non_persistent_primitive")
 
     SeenTypes seenTypes;
     SeenTypePacks seenTypePacks;
+    CloneState cloneState;
 
     // Create a new number type that isn't persistent
     unfreeze(typeChecker.globalTypes);
     TypeId oldNumber = typeChecker.globalTypes.addType(PrimitiveTypeVar{PrimitiveTypeVar::Number});
     freeze(typeChecker.globalTypes);
-    TypeId newNumber = clone(oldNumber, dest, seenTypes, seenTypePacks);
+    TypeId newNumber = clone(oldNumber, dest, seenTypes, seenTypePacks, cloneState);
 
     CHECK_NE(newNumber, oldNumber);
     CHECK_EQ(*oldNumber, *newNumber);
@@ -89,9 +91,10 @@ TEST_CASE_FIXTURE(Fixture, "deepClone_cyclic_table")
 
     SeenTypes seenTypes;
     SeenTypePacks seenTypePacks;
+    CloneState cloneState;
 
     TypeArena dest;
-    TypeId counterCopy = clone(counterType, dest, seenTypes, seenTypePacks);
+    TypeId counterCopy = clone(counterType, dest, seenTypes, seenTypePacks, cloneState);
 
     TableTypeVar* ttv = getMutable<TableTypeVar>(counterCopy);
     REQUIRE(ttv != nullptr);
@@ -142,11 +145,12 @@ TEST_CASE_FIXTURE(Fixture, "deepClone_union")
 
     SeenTypes seenTypes;
     SeenTypePacks seenTypePacks;
+    CloneState cloneState;
 
     unfreeze(typeChecker.globalTypes);
     TypeId oldUnion = typeChecker.globalTypes.addType(UnionTypeVar{{typeChecker.numberType, typeChecker.stringType}});
     freeze(typeChecker.globalTypes);
-    TypeId newUnion = clone(oldUnion, dest, seenTypes, seenTypePacks);
+    TypeId newUnion = clone(oldUnion, dest, seenTypes, seenTypePacks, cloneState);
 
     CHECK_NE(newUnion, oldUnion);
     CHECK_EQ("number | string", toString(newUnion));
@@ -159,11 +163,12 @@ TEST_CASE_FIXTURE(Fixture, "deepClone_intersection")
 
     SeenTypes seenTypes;
     SeenTypePacks seenTypePacks;
+    CloneState cloneState;
 
     unfreeze(typeChecker.globalTypes);
     TypeId oldIntersection = typeChecker.globalTypes.addType(IntersectionTypeVar{{typeChecker.numberType, typeChecker.stringType}});
     freeze(typeChecker.globalTypes);
-    TypeId newIntersection = clone(oldIntersection, dest, seenTypes, seenTypePacks);
+    TypeId newIntersection = clone(oldIntersection, dest, seenTypes, seenTypePacks, cloneState);
 
     CHECK_NE(newIntersection, oldIntersection);
     CHECK_EQ("number & string", toString(newIntersection));
@@ -188,8 +193,9 @@ TEST_CASE_FIXTURE(Fixture, "clone_class")
 
     SeenTypes seenTypes;
     SeenTypePacks seenTypePacks;
+    CloneState cloneState;
 
-    TypeId cloned = clone(&exampleClass, dest, seenTypes, seenTypePacks);
+    TypeId cloned = clone(&exampleClass, dest, seenTypes, seenTypePacks, cloneState);
     const ClassTypeVar* ctv = get<ClassTypeVar>(cloned);
     REQUIRE(ctv != nullptr);
 
@@ -211,16 +217,16 @@ TEST_CASE_FIXTURE(Fixture, "clone_sanitize_free_types")
     TypeArena dest;
     SeenTypes seenTypes;
     SeenTypePacks seenTypePacks;
+    CloneState cloneState;
 
-    bool encounteredFreeType = false;
+    TypeId clonedTy = clone(&freeTy, dest, seenTypes, seenTypePacks, cloneState);
-    TypeId clonedTy = clone(&freeTy, dest, seenTypes, seenTypePacks, &encounteredFreeType);
     CHECK_EQ("any", toString(clonedTy));
-    CHECK(encounteredFreeType);
+    CHECK(cloneState.encounteredFreeType);
 
-    encounteredFreeType = false;
+    cloneState = {};
-    TypePackId clonedTp = clone(&freeTp, dest, seenTypes, seenTypePacks, &encounteredFreeType);
+    TypePackId clonedTp = clone(&freeTp, dest, seenTypes, seenTypePacks, cloneState);
     CHECK_EQ("...any", toString(clonedTp));
-    CHECK(encounteredFreeType);
+    CHECK(cloneState.encounteredFreeType);
 }
 
 TEST_CASE_FIXTURE(Fixture, "clone_seal_free_tables")
@@ -232,12 +238,12 @@ TEST_CASE_FIXTURE(Fixture, "clone_seal_free_tables")
     TypeArena dest;
     SeenTypes seenTypes;
     SeenTypePacks seenTypePacks;
+    CloneState cloneState;
 
-    bool encounteredFreeType = false;
+    TypeId cloned = clone(&tableTy, dest, seenTypes, seenTypePacks, cloneState);
-    TypeId cloned = clone(&tableTy, dest, seenTypes, seenTypePacks, &encounteredFreeType);
     const TableTypeVar* clonedTtv = get<TableTypeVar>(cloned);
     CHECK_EQ(clonedTtv->state, TableState::Sealed);
-    CHECK(encounteredFreeType);
+    CHECK(cloneState.encounteredFreeType);
 }
 
 TEST_CASE_FIXTURE(Fixture, "clone_self_property")
@@ -267,4 +273,34 @@ TEST_CASE_FIXTURE(Fixture, "clone_self_property")
                                          "dot or pass 1 extra nil to suppress this warning");
 }
 
+TEST_CASE_FIXTURE(Fixture, "clone_recursion_limit")
+{
+#if defined(_DEBUG) || defined(_NOOPT)
+    int limit = 250;
+#else
+    int limit = 500;
+#endif
+    ScopedFastInt luauTypeCloneRecursionLimit{"LuauTypeCloneRecursionLimit", limit};
+
+    TypeArena src;
+
+    TypeId table = src.addType(TableTypeVar{});
+    TypeId nested = table;
+
+    for (unsigned i = 0; i < limit + 100; i++)
+    {
+        TableTypeVar* ttv = getMutable<TableTypeVar>(nested);
+
+        ttv->props["a"].type = src.addType(TableTypeVar{});
+        nested = ttv->props["a"].type;
+    }
+
+    TypeArena dest;
+    SeenTypes seenTypes;
+    SeenTypePacks seenTypePacks;
+    CloneState cloneState;
+
+    CHECK_THROWS_AS(clone(table, dest, seenTypes, seenTypePacks, cloneState), std::runtime_error);
+}
+
 TEST_SUITE_END();

tests/Parser.test.cpp

@@ -2518,8 +2518,6 @@ TEST_CASE_FIXTURE(Fixture, "parse_if_else_expression")
 
 TEST_CASE_FIXTURE(Fixture, "parse_type_pack_type_parameters")
 {
-    ScopedFastFlag luauParseTypePackTypeParameters("LuauParseTypePackTypeParameters", true);
-
     AstStat* stat = parse(R"(
 type Packed<T...> = () -> T...
 

tests/ToDot.test.cpp

@@ -0,0 +1,366 @@
+// This file is part of the Luau programming language and is licensed under MIT License; see LICENSE.txt for details
+
+#include "Luau/Scope.h"
+#include "Luau/ToDot.h"
+
+#include "Fixture.h"
+
+#include "doctest.h"
+
+using namespace Luau;
+
+struct ToDotClassFixture : Fixture
+{
+    ToDotClassFixture()
+    {
+        TypeArena& arena = typeChecker.globalTypes;
+
+        unfreeze(arena);
+
+        TypeId baseClassMetaType = arena.addType(TableTypeVar{});
+
+        TypeId baseClassInstanceType = arena.addType(ClassTypeVar{"BaseClass", {}, std::nullopt, baseClassMetaType, {}, {}});
+        getMutable<ClassTypeVar>(baseClassInstanceType)->props = {
+            {"BaseField", {typeChecker.numberType}},
+        };
+        typeChecker.globalScope->exportedTypeBindings["BaseClass"] = TypeFun{{}, baseClassInstanceType};
+
+        TypeId childClassInstanceType = arena.addType(ClassTypeVar{"ChildClass", {}, baseClassInstanceType, std::nullopt, {}, {}});
+        getMutable<ClassTypeVar>(childClassInstanceType)->props = {
+            {"ChildField", {typeChecker.stringType}},
+        };
+        typeChecker.globalScope->exportedTypeBindings["ChildClass"] = TypeFun{{}, childClassInstanceType};
+
+        freeze(arena);
+    }
+};
+
+TEST_SUITE_BEGIN("ToDot");
+
+TEST_CASE_FIXTURE(Fixture, "primitive")
+{
+    CheckResult result = check(R"(
+local a: nil
+local b: number
+local c: any
+)");
+    LUAU_REQUIRE_NO_ERRORS(result);
+
+    CHECK_NE("nil", toDot(requireType("a")));
+
+    CHECK_EQ(R"(digraph graphname {
+n1 [label="number"];
+})",
+        toDot(requireType("b")));
+
+    CHECK_EQ(R"(digraph graphname {
+n1 [label="any"];
+})",
+        toDot(requireType("c")));
+
+    ToDotOptions opts;
+    opts.showPointers = false;
+    opts.duplicatePrimitives = false;
+
+    CHECK_EQ(R"(digraph graphname {
+n1 [label="PrimitiveTypeVar number"];
+})",
+        toDot(requireType("b"), opts));
+
+    CHECK_EQ(R"(digraph graphname {
+n1 [label="AnyTypeVar 1"];
+})",
+        toDot(requireType("c"), opts));
+}
+
+TEST_CASE_FIXTURE(Fixture, "bound")
+{
+    CheckResult result = check(R"(
+local a = 444
+local b = a
+)");
+    LUAU_REQUIRE_NO_ERRORS(result);
+
+    std::optional<TypeId> ty = getType("b");
+    REQUIRE(bool(ty));
+
+    ToDotOptions opts;
+    opts.showPointers = false;
+    CHECK_EQ(R"(digraph graphname {
+n1 [label="BoundTypeVar 1"];
+n1 -> n2;
+n2 [label="number"];
+})",
+        toDot(*ty, opts));
+}
+
+TEST_CASE_FIXTURE(Fixture, "function")
+{
+    ScopedFastFlag luauQuantifyInPlace2{"LuauQuantifyInPlace2", true};
+
+    CheckResult result = check(R"(
+local function f(a, ...: string) return a end
+)");
+    LUAU_REQUIRE_NO_ERRORS(result);
+
+    ToDotOptions opts;
+    opts.showPointers = false;
+    CHECK_EQ(R"(digraph graphname {
+n1 [label="FunctionTypeVar 1"];
+n1 -> n2 [label="arg"];
+n2 [label="TypePack 2"];
+n2 -> n3;
+n3 [label="GenericTypeVar 3"];
+n2 -> n4 [label="tail"];
+n4 [label="VariadicTypePack 4"];
+n4 -> n5;
+n5 [label="string"];
+n1 -> n6 [label="ret"];
+n6 [label="BoundTypePack 6"];
+n6 -> n7;
+n7 [label="TypePack 7"];
+n7 -> n3;
+})",
+        toDot(requireType("f"), opts));
+}
+
+TEST_CASE_FIXTURE(Fixture, "union")
+{
+    CheckResult result = check(R"(
+local a: string | number
+)");
+    LUAU_REQUIRE_NO_ERRORS(result);
+
+    ToDotOptions opts;
+    opts.showPointers = false;
+    CHECK_EQ(R"(digraph graphname {
+n1 [label="UnionTypeVar 1"];
+n1 -> n2;
+n2 [label="string"];
+n1 -> n3;
+n3 [label="number"];
+})",
+        toDot(requireType("a"), opts));
+}
+
+TEST_CASE_FIXTURE(Fixture, "intersection")
+{
+    CheckResult result = check(R"(
+local a: string & number -- uninhabited
+)");
+    LUAU_REQUIRE_NO_ERRORS(result);
+
+    ToDotOptions opts;
+    opts.showPointers = false;
+    CHECK_EQ(R"(digraph graphname {
+n1 [label="IntersectionTypeVar 1"];
+n1 -> n2;
+n2 [label="string"];
+n1 -> n3;
+n3 [label="number"];
+})",
+        toDot(requireType("a"), opts));
+}
+
+TEST_CASE_FIXTURE(Fixture, "table")
+{
+    CheckResult result = check(R"(
+type A<T, U...> = { x: T, y: (U...) -> (), [string]: any }
+local a: A<number, ...string>
+)");
+    LUAU_REQUIRE_NO_ERRORS(result);
+
+    ToDotOptions opts;
+    opts.showPointers = false;
+    CHECK_EQ(R"(digraph graphname {
+n1 [label="TableTypeVar A"];
+n1 -> n2 [label="x"];
+n2 [label="number"];
+n1 -> n3 [label="y"];
+n3 [label="FunctionTypeVar 3"];
+n3 -> n4 [label="arg"];
+n4 [label="VariadicTypePack 4"];
+n4 -> n5;
+n5 [label="string"];
+n3 -> n6 [label="ret"];
+n6 [label="TypePack 6"];
+n1 -> n7 [label="[index]"];
+n7 [label="string"];
+n1 -> n8 [label="[value]"];
+n8 [label="any"];
+n1 -> n9 [label="typeParam"];
+n9 [label="number"];
+n1 -> n4 [label="typePackParam"];
+})",
+        toDot(requireType("a"), opts));
+
+    // Extra coverage with pointers (unstable values)
+    (void)toDot(requireType("a"));
+}
+
+TEST_CASE_FIXTURE(Fixture, "metatable")
+{
+    CheckResult result = check(R"(
+local a: typeof(setmetatable({}, {}))
+)");
+    LUAU_REQUIRE_NO_ERRORS(result);
+
+    ToDotOptions opts;
+    opts.showPointers = false;
+    CHECK_EQ(R"(digraph graphname {
+n1 [label="MetatableTypeVar 1"];
+n1 -> n2 [label="table"];
+n2 [label="TableTypeVar 2"];
+n1 -> n3 [label="metatable"];
+n3 [label="TableTypeVar 3"];
+})",
+        toDot(requireType("a"), opts));
+}
+
+TEST_CASE_FIXTURE(Fixture, "free")
+{
+    TypeVar type{TypeVariant{FreeTypeVar{TypeLevel{0, 0}}}};
+
+    ToDotOptions opts;
+    opts.showPointers = false;
+    CHECK_EQ(R"(digraph graphname {
+n1 [label="FreeTypeVar 1"];
+})",
+        toDot(&type, opts));
+}
+
+TEST_CASE_FIXTURE(Fixture, "error")
+{
+    TypeVar type{TypeVariant{ErrorTypeVar{}}};
+
+    ToDotOptions opts;
+    opts.showPointers = false;
+    CHECK_EQ(R"(digraph graphname {
+n1 [label="ErrorTypeVar 1"];
+})",
+        toDot(&type, opts));
+}
+
+TEST_CASE_FIXTURE(Fixture, "generic")
+{
+    TypeVar type{TypeVariant{GenericTypeVar{"T"}}};
+
+    ToDotOptions opts;
+    opts.showPointers = false;
+    CHECK_EQ(R"(digraph graphname {
+n1 [label="GenericTypeVar T"];
+})",
+        toDot(&type, opts));
+}
+
+TEST_CASE_FIXTURE(ToDotClassFixture, "class")
+{
+    CheckResult result = check(R"(
+local a: ChildClass
+)");
+    LUAU_REQUIRE_NO_ERRORS(result);
+
+    ToDotOptions opts;
+    opts.showPointers = false;
+    CHECK_EQ(R"(digraph graphname {
+n1 [label="ClassTypeVar ChildClass"];
+n1 -> n2 [label="ChildField"];
+n2 [label="string"];
+n1 -> n3 [label="[parent]"];
+n3 [label="ClassTypeVar BaseClass"];
+n3 -> n4 [label="BaseField"];
+n4 [label="number"];
+n3 -> n5 [label="[metatable]"];
+n5 [label="TableTypeVar 5"];
+})",
+        toDot(requireType("a"), opts));
+}
+
+TEST_CASE_FIXTURE(Fixture, "free_pack")
+{
+    TypePackVar pack{TypePackVariant{FreeTypePack{TypeLevel{0, 0}}}};
+
+    ToDotOptions opts;
+    opts.showPointers = false;
+    CHECK_EQ(R"(digraph graphname {
+n1 [label="FreeTypePack 1"];
+})",
+        toDot(&pack, opts));
+}
+
+TEST_CASE_FIXTURE(Fixture, "error_pack")
+{
+    TypePackVar pack{TypePackVariant{Unifiable::Error{}}};
+
+    ToDotOptions opts;
+    opts.showPointers = false;
+    CHECK_EQ(R"(digraph graphname {
+n1 [label="ErrorTypePack 1"];
+})",
+        toDot(&pack, opts));
+
+    // Extra coverage with pointers (unstable values)
+    (void)toDot(&pack);
+}
+
+TEST_CASE_FIXTURE(Fixture, "generic_pack")
+{
+    TypePackVar pack1{TypePackVariant{GenericTypePack{}}};
+    TypePackVar pack2{TypePackVariant{GenericTypePack{"T"}}};
+
+    ToDotOptions opts;
+    opts.showPointers = false;
+    CHECK_EQ(R"(digraph graphname {
+n1 [label="GenericTypePack 1"];
+})",
+        toDot(&pack1, opts));
+
+    CHECK_EQ(R"(digraph graphname {
+n1 [label="GenericTypePack T"];
+})",
+        toDot(&pack2, opts));
+}
+
+TEST_CASE_FIXTURE(Fixture, "bound_pack")
+{
+    TypePackVar pack{TypePackVariant{TypePack{{typeChecker.numberType}, {}}}};
+    TypePackVar bound{TypePackVariant{BoundTypePack{&pack}}};
+
+    ToDotOptions opts;
+    opts.showPointers = false;
+    CHECK_EQ(R"(digraph graphname {
+n1 [label="BoundTypePack 1"];
+n1 -> n2;
+n2 [label="TypePack 2"];
+n2 -> n3;
+n3 [label="number"];
+})",
+        toDot(&bound, opts));
+}
+
+TEST_CASE_FIXTURE(Fixture, "bound_table")
+{
+    CheckResult result = check(R"(
+local a = {x=2}
+local b
+b.x = 2
+b = a
+)");
+    LUAU_REQUIRE_NO_ERRORS(result);
+
+    std::optional<TypeId> ty = getType("b");
+    REQUIRE(bool(ty));
+
+    ToDotOptions opts;
+    opts.showPointers = false;
+    CHECK_EQ(R"(digraph graphname {
+n1 [label="TableTypeVar 1"];
+n1 -> n2 [label="boundTo"];
+n2 [label="TableTypeVar a"];
+n2 -> n3 [label="x"];
+n3 [label="number"];
+})",
+        toDot(*ty, opts));
+}
+
+TEST_SUITE_END();

tests/Transpiler.test.cpp

@@ -445,9 +445,6 @@ local a: Import.Type
 
 TEST_CASE_FIXTURE(Fixture, "transpile_type_packs")
 {
-    ScopedFastFlag luauTypeAliasPacks("LuauTypeAliasPacks", true);
-    ScopedFastFlag luauParseTypePackTypeParameters("LuauParseTypePackTypeParameters", true);
-
     std::string code = R"(
 type Packed<T...> = (T...)->(T...)
 local a: Packed<>

tests/TypeInfer.aliases.test.cpp

@@ -537,8 +537,6 @@ TEST_CASE_FIXTURE(Fixture, "free_variables_from_typeof_in_aliases")
 
 TEST_CASE_FIXTURE(Fixture, "non_recursive_aliases_that_reuse_a_generic_name")
 {
-    ScopedFastFlag sff1{"LuauSubstitutionDontReplaceIgnoredTypes", true};
-
     CheckResult result = check(R"(
         type Array<T> = { [number]: T }
         type Tuple<T, V> = Array<T | V>

tests/TypeInfer.generics.test.cpp

@@ -609,8 +609,6 @@ TEST_CASE_FIXTURE(Fixture, "typefuns_sharing_types")
 
 TEST_CASE_FIXTURE(Fixture, "bound_tables_do_not_clone_original_fields")
 {
-    ScopedFastFlag luauCloneBoundTables{"LuauCloneBoundTables", true};
-
     CheckResult result = check(R"(
 local exports = {}
 local nested = {}
@@ -627,4 +625,23 @@ return exports
     LUAU_REQUIRE_NO_ERRORS(result);
 }
 
+TEST_CASE_FIXTURE(Fixture, "instantiated_function_argument_names")
+{
+    ScopedFastFlag luauFunctionArgumentNameSize{"LuauFunctionArgumentNameSize", true};
+
+    CheckResult result = check(R"(
+local function f<T, U...>(a: T, ...: U...) end
+
+f(1, 2, 3)
+    )");
+
+    LUAU_REQUIRE_NO_ERRORS(result);
+
+    auto ty = findTypeAtPosition(Position(3, 0));
+    REQUIRE(ty);
+    ToStringOptions opts;
+    opts.functionTypeArguments = true;
+    CHECK_EQ(toString(*ty, opts), "(a: number, number, number) -> ()");
+}
+
 TEST_SUITE_END();

tests/TypeInfer.provisional.test.cpp

@@ -31,8 +31,6 @@ TEST_SUITE_BEGIN("ProvisionalTests");
  */
 TEST_CASE_FIXTURE(Fixture, "typeguard_inference_incomplete")
 {
-    ScopedFastFlag luauTypeAliasPacks("LuauTypeAliasPacks", true);
-
     const std::string code = R"(
         function f(a)
             if type(a) == "boolean" then

tests/TypeInfer.tables.test.cpp

@@ -2022,4 +2022,74 @@ caused by:
   Property '__call' is not compatible. Type '(a, b) -> ()' could not be converted into '<a>(a) -> ()')");
 }
 
+TEST_CASE_FIXTURE(Fixture, "explicitly_typed_table")
+{
+    ScopedFastFlag sffs[] {
+        {"LuauPropertiesGetExpectedType", true},
+        {"LuauExpectedTypesOfProperties", true},
+        {"LuauTableSubtypingVariance", true},
+    };
+
+    CheckResult result = check(R"(
+--!strict
+type Super = { x : number }
+type Sub = { x : number, y: number }
+type HasSuper = { p : Super }
+type HasSub = { p : Sub }
+local a: HasSuper = { p = { x = 5, y = 7 }}
+a.p = { x = 9 }
+    )");
+
+    LUAU_REQUIRE_NO_ERRORS(result);
+}
+
+TEST_CASE_FIXTURE(Fixture, "explicitly_typed_table_error")
+{
+    ScopedFastFlag sffs[] {
+        {"LuauPropertiesGetExpectedType", true},
+        {"LuauExpectedTypesOfProperties", true},
+        {"LuauTableSubtypingVariance", true},
+        {"LuauExtendedTypeMismatchError", true},
+    };
+
+    CheckResult result = check(R"(
+--!strict
+type Super = { x : number }
+type Sub = { x : number, y: number }
+type HasSuper = { p : Super }
+type HasSub = { p : Sub }
+local tmp = { p = { x = 5, y = 7 }}
+local a: HasSuper = tmp
+a.p = { x = 9 }
+-- needs to be an error because
+local y: number = tmp.p.y
+    )");
+
+    LUAU_REQUIRE_ERROR_COUNT(1, result);
+    CHECK_EQ(toString(result.errors[0]), R"(Type 'tmp' could not be converted into 'HasSuper'
+caused by:
+  Property 'p' is not compatible. Table type '{| x: number, y: number |}' not compatible with type 'Super' because the former has extra field 'y')");
+}
+
+TEST_CASE_FIXTURE(Fixture, "explicitly_typed_table_with_indexer")
+{
+    ScopedFastFlag sffs[] {
+        {"LuauPropertiesGetExpectedType", true},
+        {"LuauExpectedTypesOfProperties", true},
+        {"LuauTableSubtypingVariance", true},
+    };
+
+    CheckResult result = check(R"(
+--!strict
+type Super = { x : number }
+type Sub = { x : number, y: number }
+type HasSuper = { [string] : Super }
+type HasSub = { [string] : Sub }
+local a: HasSuper = { p = { x = 5, y = 7 }}
+a.p = { x = 9 }
+    )");
+
+    LUAU_REQUIRE_NO_ERRORS(result);
+}
+
 TEST_SUITE_END();

tests/TypeInfer.test.cpp

@@ -4779,4 +4779,24 @@ local bar = foo.nutrition + 100
     // CHECK_EQ("Unknown type used in + operation; consider adding a type annotation to 'foo'", toString(result.errors[1]));
 }
 
+TEST_CASE_FIXTURE(Fixture, "require_failed_module")
+{
+    ScopedFastFlag luauModuleRequireErrorPack{"LuauModuleRequireErrorPack", true};
+
+    fileResolver.source["game/A"] = R"(
+return unfortunately()
+    )";
+
+    CheckResult aResult = frontend.check("game/A");
+    LUAU_REQUIRE_ERRORS(aResult);
+
+    CheckResult result = check(R"(
+local ModuleA = require(game.A)
+    )");
+    LUAU_REQUIRE_NO_ERRORS(result);
+
+    std::optional<TypeId> oty = requireType("ModuleA");
+    CHECK_EQ("*unknown*", toString(*oty));
+}
+
 TEST_SUITE_END();

tests/TypeInfer.typePacks.cpp

@@ -296,9 +296,6 @@ end
 
 TEST_CASE_FIXTURE(Fixture, "type_alias_type_packs")
 {
-    ScopedFastFlag luauTypeAliasPacks("LuauTypeAliasPacks", true);
-    ScopedFastFlag luauParseTypePackTypeParameters("LuauParseTypePackTypeParameters", true);
-
     CheckResult result = check(R"(
 type Packed<T...> = (T...) -> T...
 local a: Packed<>
@@ -360,9 +357,6 @@ local c: Packed<string, number, boolean>
 
 TEST_CASE_FIXTURE(Fixture, "type_alias_type_packs_import")
 {
-    ScopedFastFlag luauTypeAliasPacks("LuauTypeAliasPacks", true);
-    ScopedFastFlag luauParseTypePackTypeParameters("LuauParseTypePackTypeParameters", true);
-
     fileResolver.source["game/A"] = R"(
 export type Packed<T, U...> = { a: T, b: (U...) -> () }
 return {}
@@ -393,9 +387,6 @@ local d: { a: typeof(c) }
 
 TEST_CASE_FIXTURE(Fixture, "type_pack_type_parameters")
 {
-    ScopedFastFlag luauTypeAliasPacks("LuauTypeAliasPacks", true);
-    ScopedFastFlag luauParseTypePackTypeParameters("LuauParseTypePackTypeParameters", true);
-
     fileResolver.source["game/A"] = R"(
 export type Packed<T, U...> = { a: T, b: (U...) -> () }
 return {}
@@ -431,9 +422,6 @@ type C<X...> = Import.Packed<string, (number, X...)>
 
 TEST_CASE_FIXTURE(Fixture, "type_alias_type_packs_nested")
 {
-    ScopedFastFlag luauTypeAliasPacks("LuauTypeAliasPacks", true);
-    ScopedFastFlag luauParseTypePackTypeParameters("LuauParseTypePackTypeParameters", true);
-
     CheckResult result = check(R"(
 type Packed1<T...> = (T...) -> (T...)
 type Packed2<T...> = (Packed1<T...>, T...) -> (Packed1<T...>, T...)
@@ -452,9 +440,6 @@ type Packed4<T...> = (Packed3<T...>, T...) -> (Packed3<T...>, T...)
 
 TEST_CASE_FIXTURE(Fixture, "type_alias_type_pack_variadic")
 {
-    ScopedFastFlag luauTypeAliasPacks("LuauTypeAliasPacks", true);
-    ScopedFastFlag luauParseTypePackTypeParameters("LuauParseTypePackTypeParameters", true);
-
     CheckResult result = check(R"(
 type X<T...> = (T...) -> (string, T...)
 
@@ -470,9 +455,6 @@ type E = X<(number, ...string)>
 
 TEST_CASE_FIXTURE(Fixture, "type_alias_type_pack_multi")
 {
-    ScopedFastFlag luauTypeAliasPacks("LuauTypeAliasPacks", true);
-    ScopedFastFlag luauParseTypePackTypeParameters("LuauParseTypePackTypeParameters", true);
-
     CheckResult result = check(R"(
 type Y<T..., U...> = (T...) -> (U...)
 type A<S...> = Y<S..., S...>
@@ -501,9 +483,6 @@ type I<S..., R...> = W<number, (string, S...), R...>
 
 TEST_CASE_FIXTURE(Fixture, "type_alias_type_pack_explicit")
 {
-    ScopedFastFlag luauTypeAliasPacks("LuauTypeAliasPacks", true);
-    ScopedFastFlag luauParseTypePackTypeParameters("LuauParseTypePackTypeParameters", true);
-
     CheckResult result = check(R"(
 type X<T...> = (T...) -> (T...)
 
@@ -527,9 +506,6 @@ type F = X<(string, ...number)>
 
 TEST_CASE_FIXTURE(Fixture, "type_alias_type_pack_explicit_multi")
 {
-    ScopedFastFlag luauTypeAliasPacks("LuauTypeAliasPacks", true);
-    ScopedFastFlag luauParseTypePackTypeParameters("LuauParseTypePackTypeParameters", true);
-
     CheckResult result = check(R"(
 type Y<T..., U...> = (T...) -> (U...)
 
@@ -549,9 +525,6 @@ type D<X...> = Y<X..., (number, string, X...)>
 
 TEST_CASE_FIXTURE(Fixture, "type_alias_type_pack_explicit_multi_tostring")
 {
-    ScopedFastFlag luauTypeAliasPacks("LuauTypeAliasPacks", true);
-    ScopedFastFlag luauParseTypePackTypeParameters("LuauParseTypePackTypeParameters", true);
-
     CheckResult result = check(R"(
 type Y<T..., U...> = { f: (T...) -> (U...) }
 
@@ -567,9 +540,6 @@ local b: Y<(), ()>
 
 TEST_CASE_FIXTURE(Fixture, "type_alias_backwards_compatible")
 {
-    ScopedFastFlag luauTypeAliasPacks("LuauTypeAliasPacks", true);
-    ScopedFastFlag luauParseTypePackTypeParameters("LuauParseTypePackTypeParameters", true);
-
     CheckResult result = check(R"(
 type X<T> = () -> T
 type Y<T, U> = (T) -> U
@@ -588,9 +558,6 @@ type C = Y<(number), boolean>
 
 TEST_CASE_FIXTURE(Fixture, "type_alias_type_packs_errors")
 {
-    ScopedFastFlag luauTypeAliasPacks("LuauTypeAliasPacks", true);
-    ScopedFastFlag luauParseTypePackTypeParameters("LuauParseTypePackTypeParameters", true);
-
     CheckResult result = check(R"(
 type Packed<T, U, V...> = (T, U) -> (V...)
 local b: Packed<number>

tests/TypeVar.test.cpp

@@ -3,6 +3,7 @@
 #include "Luau/Scope.h"
 #include "Luau/TypeInfer.h"
 #include "Luau/TypeVar.h"
+#include "Luau/VisitTypeVar.h"
 
 #include "Fixture.h"
 #include "ScopedFlags.h"
@@ -323,4 +324,48 @@ TEST_CASE("tagging_props")
     CHECK(Luau::hasTag(prop, "foo"));
 }
 
+struct VisitCountTracker
+{
+    std::unordered_map<TypeId, unsigned> tyVisits;
+    std::unordered_map<TypePackId, unsigned> tpVisits;
+
+    void cycle(TypeId) {}
+    void cycle(TypePackId) {}
+
+    template<typename T>
+    bool operator()(TypeId ty, const T& t)
+    {
+        tyVisits[ty]++;
+        return true;
+    }
+
+    template<typename T>
+    bool operator()(TypePackId tp, const T&)
+    {
+        tpVisits[tp]++;
+        return true;
+    }
+};
+
+TEST_CASE_FIXTURE(Fixture, "visit_once")
+{
+    CheckResult result = check(R"(
+type T = { a: number, b: () -> () }
+local b: (T, T, T) -> T
+)");
+    LUAU_REQUIRE_NO_ERRORS(result);
+
+    TypeId bType = requireType("b");
+
+    VisitCountTracker tester;
+    DenseHashSet<void*> seen{nullptr};
+    visitTypeVarOnce(bType, tester, seen);
+
+    for (auto [_, count] : tester.tyVisits)
+        CHECK_EQ(count, 1);
+
+    for (auto [_, count] : tester.tpVisits)
+        CHECK_EQ(count, 1);
+}
+
 TEST_SUITE_END();

tests/conformance/apicalls.lua

@@ -2,7 +2,13 @@
 print('testing function calls through API')
 
 function add(a, b)
-	return a + b
+  return a + b
+end
+
+local m = { __eq = function(a, b) return a.a == b.a end }
+
+function create_with_tm(x)
+  return setmetatable({ a = x }, m)
 end
 
 return('OK')

tests/conformance/basic.lua

@@ -441,7 +441,8 @@ assert((function() a = {} b = {} mt = { __eq = function(l, r) return #l == #r en
 assert((function() a = {} b = {} function eq(l, r) return #l == #r end setmetatable(a, {__eq = eq}) setmetatable(b, {__eq = eq}) return concat(a == b, a ~= b) end)() == "true,false")
 assert((function() a = {} b = {} setmetatable(a, {__eq = function(l, r) return #l == #r end}) setmetatable(b, {__eq = function(l, r) return #l == #r end}) return concat(a == b, a ~= b) end)() == "false,true")
 
--- userdata, reference equality (no mt)
+-- userdata, reference equality (no mt or mt.__eq)
+assert((function() a = newproxy() return concat(a == newproxy(),a ~= newproxy()) end)() == "false,true")
 assert((function() a = newproxy(true) return concat(a == newproxy(true),a ~= newproxy(true)) end)() == "false,true")
 
 -- rawequal
@@ -876,4 +877,4 @@ assert(concat(typeof(5), typeof(nil), typeof({}), typeof(newproxy())) == "number
 
 testgetfenv() -- DONT MOVE THIS LINE
 
-return'OK'
+return 'OK'

tests/conformance/closure.lua

@@ -419,11 +419,5 @@ co = coroutine.create(function ()
        return loadstring("return a")()
      end)
 
-a = {a = 15}
--- debug.setfenv(co, a)
--- assert(debug.getfenv(co) == a)
--- assert(select(2, coroutine.resume(co)) == a)
--- assert(select(2, coroutine.resume(co)) == a.a)
 
-
+return 'OK'
-return'OK'

tests/conformance/constructs.lua

@@ -237,4 +237,4 @@ repeat
   i = i+1
 until i==c
 
-return'OK'
+return 'OK'

tests/conformance/coroutine.lua

@@ -373,4 +373,4 @@ do
   assert(f() == 42)
 end
 
-return'OK'
+return 'OK'

tests/conformance/datetime.lua

@@ -74,4 +74,4 @@ assert(os.difftime(t1,t2) == 60*2-19)
 
 assert(os.time({ year = 1970, day = 1, month = 1, hour = 0}) == 0)
 
-return'OK'
+return 'OK'

tests/conformance/debug.lua

@@ -98,4 +98,4 @@ assert(quuz(function(...) end) == "0 true")
 assert(quuz(function(a, b) end) == "2 false")
 assert(quuz(function(a, b, ...) end) == "2 true")
 
-return'OK'
+return 'OK'

tests/conformance/errors.lua

@@ -34,15 +34,15 @@ assert(doit("error('hi', 0)") == 'hi')
 assert(doit("unpack({}, 1, n=2^30)"))
 assert(doit("a=math.sin()"))
 assert(not doit("tostring(1)") and doit("tostring()"))
-assert(doit"tonumber()")
+assert(doit("tonumber()"))
-assert(doit"repeat until 1; a")
+assert(doit("repeat until 1; a"))
 checksyntax("break label", "", "label", 1)
-assert(doit";")
+assert(doit(";"))
-assert(doit"a=1;;")
+assert(doit("a=1;;"))
-assert(doit"return;;")
+assert(doit("return;;"))
-assert(doit"assert(false)")
+assert(doit("assert(false)"))
-assert(doit"assert(nil)")
+assert(doit("assert(nil)"))
-assert(doit"a=math.sin\n(3)")
+assert(doit("a=math.sin\n(3)"))
 assert(doit("function a (... , ...) end"))
 assert(doit("function a (, ...) end"))
 
@@ -59,7 +59,7 @@ checkmessage("a=1; local a,bbbb=2,3; a = math.sin(1) and bbbb(3)",
        "local 'bbbb'")
 checkmessage("a={}; do local a=1 end a:bbbb(3)", "method 'bbbb'")
 checkmessage("local a={}; a.bbbb(3)", "field 'bbbb'")
-assert(not string.find(doit"a={13}; local bbbb=1; a[bbbb](3)", "'bbbb'"))
+assert(not string.find(doit("a={13}; local bbbb=1; a[bbbb](3)"), "'bbbb'"))
 checkmessage("a={13}; local bbbb=1; a[bbbb](3)", "number")
 
 aaa = nil
@@ -67,14 +67,14 @@ checkmessage("aaa.bbb:ddd(9)", "global 'aaa'")
 checkmessage("local aaa={bbb=1}; aaa.bbb:ddd(9)", "field 'bbb'")
 checkmessage("local aaa={bbb={}}; aaa.bbb:ddd(9)", "method 'ddd'")
 checkmessage("local a,b,c; (function () a = b+1 end)()", "upvalue 'b'")
-assert(not doit"local aaa={bbb={ddd=next}}; aaa.bbb:ddd(nil)")
+assert(not doit("local aaa={bbb={ddd=next}}; aaa.bbb:ddd(nil)"))
 
 checkmessage("b=1; local aaa='a'; x=aaa+b", "local 'aaa'")
 checkmessage("aaa={}; x=3/aaa", "global 'aaa'")
 checkmessage("aaa='2'; b=nil;x=aaa*b", "global 'b'")
 checkmessage("aaa={}; x=-aaa", "global 'aaa'")
-assert(not string.find(doit"aaa={}; x=(aaa or aaa)+(aaa and aaa)", "'aaa'"))
+assert(not string.find(doit("aaa={}; x=(aaa or aaa)+(aaa and aaa)"), "'aaa'"))
-assert(not string.find(doit"aaa={}; (aaa or aaa)()", "'aaa'"))
+assert(not string.find(doit("aaa={}; (aaa or aaa)()"), "'aaa'"))
 
 checkmessage([[aaa=9
 repeat until 3==3
@@ -122,10 +122,10 @@ function lineerror (s)
   return line and line+0
 end
 
-assert(lineerror"local a\n for i=1,'a' do \n print(i) \n end" == 2)
+assert(lineerror("local a\n for i=1,'a' do \n print(i) \n end") == 2)
--- assert(lineerror"\n local a \n for k,v in 3 \n do \n print(k) \n end" == 3)
+-- assert(lineerror("\n local a \n for k,v in 3 \n do \n print(k) \n end") == 3)
--- assert(lineerror"\n\n for k,v in \n 3 \n do \n print(k) \n end" == 4)
+-- assert(lineerror("\n\n for k,v in \n 3 \n do \n print(k) \n end") == 4)
-assert(lineerror"function a.x.y ()\na=a+1\nend" == 1)
+assert(lineerror("function a.x.y ()\na=a+1\nend") == 1)
 
 local p = [[
 function g() f() end

tests/conformance/gc.lua

@@ -77,7 +77,7 @@ end
 
 local function dosteps (siz)
   collectgarbage()
-  collectgarbage"stop"
+  collectgarbage("stop")
   local a = {}
   for i=1,100 do a[i] = {{}}; local b = {} end
   local x = gcinfo()
@@ -99,11 +99,11 @@ assert(dosteps(10000) == 1)
 do
   local x = gcinfo()
   collectgarbage()
-  collectgarbage"stop"
+  collectgarbage("stop")
   repeat
     local a = {}
   until gcinfo() > 1000
-  collectgarbage"restart"
+  collectgarbage("restart")
   repeat
     local a = {}
   until gcinfo() < 1000
@@ -123,7 +123,7 @@ for n in pairs(b) do
 end
 b = nil
 collectgarbage()
-for n in pairs(a) do error'cannot be here' end
+for n in pairs(a) do error("cannot be here") end
 for i=1,lim do a[i] = i end
 for i=1,lim do assert(a[i] == i) end
 

tests/conformance/nextvar.lua

@@ -368,9 +368,9 @@ assert(next(a,nil) == 1000 and next(a,1000) == nil)
 assert(next({}) == nil)
 assert(next({}, nil) == nil)
 
-for a,b in pairs{} do error"not here" end
+for a,b in pairs{} do error("not here") end
-for i=1,0 do error'not here' end
+for i=1,0 do error("not here") end
-for i=0,1,-1 do error'not here' end
+for i=0,1,-1 do error("not here") end
 a = nil; for i=1,1 do assert(not a); a=1 end; assert(a)
 a = nil; for i=1,1,-1 do assert(not a); a=1 end; assert(a)
 

tests/conformance/pcall.lua

@@ -144,4 +144,4 @@ coroutine.resume(co)
 resumeerror(co, "fail")
 checkresults({ true, false, "fail" }, coroutine.resume(co))
 
-return'OK'
+return 'OK'

tests/conformance/utf8.lua

@@ -205,4 +205,4 @@ for p, c in string.gmatch(x, "()(" .. utf8.charpattern .. ")") do
   end
 end
 
-return'OK'
+return 'OK'

tests/conformance/vector.lua

@@ -1,6 +1,9 @@
 -- This file is part of the Luau programming language and is licensed under MIT License; see LICENSE.txt for details
 print('testing vectors')
 
+-- detect vector size
+local vector_size = if pcall(function() return vector(0, 0, 0).w end) then 4 else 3
+
 -- equality
 assert(vector(1, 2, 3) == vector(1, 2, 3))
 assert(vector(0, 1, 2) == vector(-0, 1, 2))
@@ -13,8 +16,14 @@ assert(not rawequal(vector(1, 2, 3), vector(1, 2, 4)))
 
 -- type & tostring
 assert(type(vector(1, 2, 3)) == "vector")
-assert(tostring(vector(1, 2, 3)) == "1, 2, 3")
+
-assert(tostring(vector(-1, 2, 0.5)) == "-1, 2, 0.5")
+if vector_size == 4 then
+	assert(tostring(vector(1, 2, 3, 4)) == "1, 2, 3, 4")
+	assert(tostring(vector(-1, 2, 0.5, 0)) == "-1, 2, 0.5, 0")
+else
+	assert(tostring(vector(1, 2, 3)) == "1, 2, 3")
+	assert(tostring(vector(-1, 2, 0.5)) == "-1, 2, 0.5")
+end
 
 local t = {}
 
@@ -42,12 +51,19 @@ assert(8 * vector(8, 16, 24) == vector(64, 128, 192));
 assert(vector(1, 2, 4) * '8' == vector(8, 16, 32));
 assert('8' * vector(8, 16, 24) == vector(64, 128, 192));
 
-assert(vector(1, 2, 4) / vector(8, 16, 24) == vector(1/8, 2/16, 4/24));
+if vector_size == 4 then
+	assert(vector(1, 2, 4, 8) / vector(8, 16, 24, 32) == vector(1/8, 2/16, 4/24, 8/32));
+	assert(8 / vector(8, 16, 24, 32) == vector(1, 1/2, 1/3, 1/4));
+	assert('8' / vector(8, 16, 24, 32) == vector(1, 1/2, 1/3, 1/4));
+else
+	assert(vector(1, 2, 4) / vector(8, 16, 24, 1) == vector(1/8, 2/16, 4/24));
+	assert(8 / vector(8, 16, 24) == vector(1, 1/2, 1/3));
+	assert('8' / vector(8, 16, 24) == vector(1, 1/2, 1/3));
+end
+
 assert(vector(1, 2, 4) / 8 == vector(1/8, 1/4, 1/2));
 assert(vector(1, 2, 4) / (1 / val) == vector(1/8, 2/8, 4/8));
-assert(8 / vector(8, 16, 24) == vector(1, 1/2, 1/3));
 assert(vector(1, 2, 4) / '8' == vector(1/8, 1/4, 1/2));
-assert('8' / vector(8, 16, 24) == vector(1, 1/2, 1/3));
 
 assert(-vector(1, 2, 4) == vector(-1, -2, -4));
 
@@ -71,4 +87,9 @@ assert(pcall(function() local t = {} rawset(t, vector(0/0, 2, 3), 1) end) == fal
 -- make sure we cover both builtin and C impl
 assert(vector(1, 2, 4) == vector("1", "2", "4"))
 
+-- additional checks for 4-component vectors
+if vector_size == 4 then
+	assert(vector(1, 2, 3, 4).w == 4)
+end
+
 return 'OK'

tools/svg.py

@@ -458,13 +458,16 @@ def display(root, title, colors, flip = False):
 
     framewidth = 1200 - 20
 
+    def pixels(x):
+        return float(x) / root.width * framewidth if root.width > 0 else 0
+
     for n in root.subtree():
-        if n.width / root.width * framewidth < 0.1:
+        if pixels(n.width) < 0.1:
             continue
 
-        x = 10 + n.offset / root.width * framewidth
+        x = 10 + pixels(n.offset)
         y = (maxdepth - 1 - n.depth if flip else n.depth) * 16 + 3 * 16
-        width = n.width / root.width * framewidth
+        width = pixels(n.width)
         height = 15
 
         if colors == "cold":