.github/workflows/build.yml

@@ -46,9 +46,9 @@ jobs:
     - name: make cli
       run: |
          make -j2 config=sanitize werror=1 luau luau-analyze luau-compile # match config with tests to improve build time
-         ./luau tests/conformance/assert.luau
-         ./luau-analyze tests/conformance/assert.luau
-         ./luau-compile tests/conformance/assert.luau
+         ./luau tests/conformance/assert.lua
+         ./luau-analyze tests/conformance/assert.lua
+         ./luau-compile tests/conformance/assert.lua
 
   windows:
     runs-on: windows-latest
@@ -81,9 +81,9 @@ jobs:
       shell: bash # necessary for fail-fast
       run: |
         cmake --build . --target Luau.Repl.CLI Luau.Analyze.CLI Luau.Compile.CLI --config Debug # match config with tests to improve build time
-        Debug/luau tests/conformance/assert.luau
-        Debug/luau-analyze tests/conformance/assert.luau
-        Debug/luau-compile tests/conformance/assert.luau
+        Debug/luau tests/conformance/assert.lua
+        Debug/luau-analyze tests/conformance/assert.lua
+        Debug/luau-compile tests/conformance/assert.lua
 
   coverage:
     runs-on: ubuntu-22.04

Analysis/include/Luau/AnyTypeSummary.h

@@ -0,0 +1,148 @@
+// This file is part of the Luau programming language and is licensed under MIT License; see LICENSE.txt for details
+#pragma once
+
+#include "Luau/AstQuery.h"
+#include "Luau/Config.h"
+#include "Luau/ModuleResolver.h"
+#include "Luau/Scope.h"
+#include "Luau/Variant.h"
+#include "Luau/Normalize.h"
+#include "Luau/TypePack.h"
+#include "Luau/TypeArena.h"
+
+#include <mutex>
+#include <string>
+#include <vector>
+#include <optional>
+
+namespace Luau
+{
+
+class AstStat;
+class ParseError;
+struct TypeError;
+struct LintWarning;
+struct GlobalTypes;
+struct ModuleResolver;
+struct ParseResult;
+struct DcrLogger;
+
+struct TelemetryTypePair
+{
+    std::string annotatedType;
+    std::string inferredType;
+};
+
+struct AnyTypeSummary
+{
+    TypeArena arena;
+
+    AstStatBlock* rootSrc = nullptr;
+    DenseHashSet<TypeId> seenTypeFamilyInstances{nullptr};
+
+    int recursionCount = 0;
+
+    std::string root;
+    int strictCount = 0;
+
+    DenseHashMap<const void*, bool> seen{nullptr};
+
+    AnyTypeSummary();
+
+    void traverse(const Module* module, AstStat* src, NotNull<BuiltinTypes> builtinTypes);
+
+    std::pair<bool, TypeId> checkForAnyCast(const Scope* scope, AstExprTypeAssertion* expr);
+
+    bool containsAny(TypePackId typ);
+    bool containsAny(TypeId typ);
+
+    bool isAnyCast(const Scope* scope, AstExpr* expr, const Module* module, NotNull<BuiltinTypes> builtinTypes);
+    bool isAnyCall(const Scope* scope, AstExpr* expr, const Module* module, NotNull<BuiltinTypes> builtinTypes);
+
+    bool hasVariadicAnys(const Scope* scope, AstExprFunction* expr, const Module* module, NotNull<BuiltinTypes> builtinTypes);
+    bool hasArgAnys(const Scope* scope, AstExprFunction* expr, const Module* module, NotNull<BuiltinTypes> builtinTypes);
+    bool hasAnyReturns(const Scope* scope, AstExprFunction* expr, const Module* module, NotNull<BuiltinTypes> builtinTypes);
+
+    TypeId checkForFamilyInhabitance(const TypeId instance, Location location);
+    TypeId lookupType(const AstExpr* expr, const Module* module, NotNull<BuiltinTypes> builtinTypes);
+    TypePackId reconstructTypePack(const AstArray<AstExpr*> exprs, const Module* module, NotNull<BuiltinTypes> builtinTypes);
+
+    DenseHashSet<TypeId> seenTypeFunctionInstances{nullptr};
+    TypeId lookupAnnotation(AstType* annotation, const Module* module, NotNull<BuiltinTypes> builtintypes);
+    std::optional<TypePackId> lookupPackAnnotation(AstTypePack* annotation, const Module* module);
+    TypeId checkForTypeFunctionInhabitance(const TypeId instance, const Location location);
+
+    enum Pattern : uint64_t
+    {
+        Casts,
+        FuncArg,
+        FuncRet,
+        FuncApp,
+        VarAnnot,
+        VarAny,
+        TableProp,
+        Alias,
+        Assign,
+        TypePk
+    };
+
+    struct TypeInfo
+    {
+        Pattern code;
+        std::string node;
+        TelemetryTypePair type;
+
+        explicit TypeInfo(Pattern code, std::string node, TelemetryTypePair type);
+    };
+
+    struct FindReturnAncestry final : public AstVisitor
+    {
+        AstNode* currNode{nullptr};
+        AstNode* stat{nullptr};
+        Position rootEnd;
+        bool found = false;
+
+        explicit FindReturnAncestry(AstNode* stat, Position rootEnd);
+
+        bool visit(AstType* node) override;
+        bool visit(AstNode* node) override;
+        bool visit(AstStatFunction* node) override;
+        bool visit(AstStatLocalFunction* node) override;
+    };
+
+    std::vector<TypeInfo> typeInfo;
+
+    /**
+     * Fabricates a scope that is a child of another scope.
+     * @param node the lexical node that the scope belongs to.
+     * @param parent the parent scope of the new scope. Must not be null.
+     */
+    const Scope* childScope(const AstNode* node, const Scope* parent);
+
+    std::optional<AstExpr*> matchRequire(const AstExprCall& call);
+    AstNode* getNode(AstStatBlock* root, AstNode* node);
+    const Scope* findInnerMostScope(const Location location, const Module* module);
+    const AstNode* findAstAncestryAtLocation(const AstStatBlock* root, AstNode* node);
+
+    void visit(const Scope* scope, AstStat* stat, const Module* module, NotNull<BuiltinTypes> builtinTypes);
+    void visit(const Scope* scope, AstStatBlock* block, const Module* module, NotNull<BuiltinTypes> builtinTypes);
+    void visit(const Scope* scope, AstStatIf* ifStatement, const Module* module, NotNull<BuiltinTypes> builtinTypes);
+    void visit(const Scope* scope, AstStatWhile* while_, const Module* module, NotNull<BuiltinTypes> builtinTypes);
+    void visit(const Scope* scope, AstStatRepeat* repeat, const Module* module, NotNull<BuiltinTypes> builtinTypes);
+    void visit(const Scope* scope, AstStatReturn* ret, const Module* module, NotNull<BuiltinTypes> builtinTypes);
+    void visit(const Scope* scope, AstStatLocal* local, const Module* module, NotNull<BuiltinTypes> builtinTypes);
+    void visit(const Scope* scope, AstStatFor* for_, const Module* module, NotNull<BuiltinTypes> builtinTypes);
+    void visit(const Scope* scope, AstStatForIn* forIn, const Module* module, NotNull<BuiltinTypes> builtinTypes);
+    void visit(const Scope* scope, AstStatAssign* assign, const Module* module, NotNull<BuiltinTypes> builtinTypes);
+    void visit(const Scope* scope, AstStatCompoundAssign* assign, const Module* module, NotNull<BuiltinTypes> builtinTypes);
+    void visit(const Scope* scope, AstStatFunction* function, const Module* module, NotNull<BuiltinTypes> builtinTypes);
+    void visit(const Scope* scope, AstStatLocalFunction* function, const Module* module, NotNull<BuiltinTypes> builtinTypes);
+    void visit(const Scope* scope, AstStatTypeAlias* alias, const Module* module, NotNull<BuiltinTypes> builtinTypes);
+    void visit(const Scope* scope, AstStatExpr* expr, const Module* module, NotNull<BuiltinTypes> builtinTypes);
+    void visit(const Scope* scope, AstStatDeclareGlobal* declareGlobal, const Module* module, NotNull<BuiltinTypes> builtinTypes);
+    void visit(const Scope* scope, AstStatDeclareClass* declareClass, const Module* module, NotNull<BuiltinTypes> builtinTypes);
+    void visit(const Scope* scope, AstStatDeclareFunction* declareFunction, const Module* module, NotNull<BuiltinTypes> builtinTypes);
+    void visit(const Scope* scope, AstStatError* error, const Module* module, NotNull<BuiltinTypes> builtinTypes);
+};
+
+} // namespace Luau

Analysis/include/Luau/BuiltinDefinitions.h

@@ -70,7 +70,6 @@ Property makeProperty(TypeId ty, std::optional<std::string> documentationSymbol
 void assignPropDocumentationSymbols(TableType::Props& props, const std::string& baseName);
 
 std::string getBuiltinDefinitionSource();
-std::string getTypeFunctionDefinitionSource();
 
 void addGlobalBinding(GlobalTypes& globals, const std::string& name, TypeId ty, const std::string& packageName);
 void addGlobalBinding(GlobalTypes& globals, const std::string& name, Binding binding);

Analysis/include/Luau/Clone.h

@@ -40,9 +40,4 @@ TypeId clone(TypeId tp, TypeArena& dest, CloneState& cloneState);
 TypeFun clone(const TypeFun& typeFun, TypeArena& dest, CloneState& cloneState);
 Binding clone(const Binding& binding, TypeArena& dest, CloneState& cloneState);
 
-TypePackId cloneIncremental(TypePackId tp, TypeArena& dest, CloneState& cloneState, Scope* freshScopeForFreeTypes);
-TypeId cloneIncremental(TypeId typeId, TypeArena& dest, CloneState& cloneState, Scope* freshScopeForFreeTypes);
-TypeFun cloneIncremental(const TypeFun& typeFun, TypeArena& dest, CloneState& cloneState, Scope* freshScopeForFreeTypes);
-Binding cloneIncremental(const Binding& binding, TypeArena& dest, CloneState& cloneState, Scope* freshScopeForFreeTypes);
-
 } // namespace Luau

Analysis/include/Luau/Constraint.h

@@ -50,7 +50,6 @@ struct GeneralizationConstraint
     TypeId sourceType;
 
     std::vector<TypeId> interiorTypes;
-    bool hasDeprecatedAttribute = false;
 };
 
 // variables ~ iterate iterator

Analysis/include/Luau/ConstraintGenerator.h

@@ -96,9 +96,6 @@ struct ConstraintGenerator
     // will enqueue them during solving.
     std::vector<ConstraintPtr> unqueuedConstraints;
 
-    // Map a function's signature scope back to its signature type.
-    DenseHashMap<Scope*, TypeId> scopeToFunction{nullptr};
-
     // The private scope of type aliases for which the type parameters belong to.
     DenseHashMap<const AstStatTypeAlias*, ScopePtr> astTypeAliasDefiningScopes{nullptr};
 
@@ -117,15 +114,12 @@ struct ConstraintGenerator
 
     // Needed to register all available type functions for execution at later stages.
     NotNull<TypeFunctionRuntime> typeFunctionRuntime;
-    DenseHashMap<const AstStatTypeFunction*, ScopePtr> astTypeFunctionEnvironmentScopes{nullptr};
-
     // Needed to resolve modules to make 'require' import types properly.
     NotNull<ModuleResolver> moduleResolver;
     // Occasionally constraint generation needs to produce an ICE.
     const NotNull<InternalErrorReporter> ice;
 
     ScopePtr globalScope;
-    ScopePtr typeFunctionScope;
 
     std::function<void(const ModuleName&, const ScopePtr&)> prepareModuleScope;
     std::vector<RequireCycle> requireCycles;
@@ -143,7 +137,6 @@ struct ConstraintGenerator
         NotNull<BuiltinTypes> builtinTypes,
         NotNull<InternalErrorReporter> ice,
         const ScopePtr& globalScope,
-        const ScopePtr& typeFunctionScope,
         std::function<void(const ModuleName&, const ScopePtr&)> prepareModuleScope,
         DcrLogger* logger,
         NotNull<DataFlowGraph> dfg,

Analysis/include/Luau/ConstraintSolver.h

@@ -88,7 +88,6 @@ struct ConstraintSolver
     NotNull<TypeFunctionRuntime> typeFunctionRuntime;
     // The entire set of constraints that the solver is trying to resolve.
     std::vector<NotNull<Constraint>> constraints;
-    NotNull<DenseHashMap<Scope*, TypeId>> scopeToFunction;
     NotNull<Scope> rootScope;
     ModuleName currentModuleName;
 
@@ -120,7 +119,6 @@ struct ConstraintSolver
     DenseHashMap<TypeId, size_t> unresolvedConstraints{{}};
 
     std::unordered_map<NotNull<const Constraint>, DenseHashSet<TypeId>> maybeMutatedFreeTypes;
-    std::unordered_map<TypeId, DenseHashSet<const Constraint*>> mutatedFreeTypeToConstraint;
 
     // Irreducible/uninhabited type functions or type pack functions.
     DenseHashSet<const void*> uninhabitedTypeFunctions{{}};
@@ -146,7 +144,6 @@ struct ConstraintSolver
         NotNull<TypeFunctionRuntime> typeFunctionRuntime,
         NotNull<Scope> rootScope,
         std::vector<NotNull<Constraint>> constraints,
-        NotNull<DenseHashMap<Scope*, TypeId>> scopeToFunction,
         ModuleName moduleName,
         NotNull<ModuleResolver> moduleResolver,
         std::vector<RequireCycle> requireCycles,
@@ -174,8 +171,6 @@ struct ConstraintSolver
     bool isDone() const;
 
 private:
-    void generalizeOneType(TypeId ty);
-
     /**
      * Bind a type variable to another type.
      *
@@ -365,7 +360,7 @@ public:
      * @returns a non-free type that generalizes the argument, or `std::nullopt` if one
      * does not exist
      */
-    std::optional<TypeId> generalizeFreeType(NotNull<Scope> scope, TypeId type);
+    std::optional<TypeId> generalizeFreeType(NotNull<Scope> scope, TypeId type, bool avoidSealingTables = false);
 
     /**
      * Checks the existing set of constraints to see if there exist any that contain

Analysis/include/Luau/DataFlowGraph.h

@@ -38,6 +38,8 @@ struct DataFlowGraph
     DefId getDef(const AstExpr* expr) const;
     // Look up the definition optionally, knowing it may not be present.
     std::optional<DefId> getDefOptional(const AstExpr* expr) const;
+    // Look up for the rvalue def for a compound assignment.
+    std::optional<DefId> getRValueDefForCompoundAssign(const AstExpr* expr) const;
 
     DefId getDef(const AstLocal* local) const;
 
@@ -64,6 +66,10 @@ private:
     // All keys in this maps are really only statements that ambiently declares a symbol.
     DenseHashMap<const AstStat*, const Def*> declaredDefs{nullptr};
 
+    // Compound assignments are in a weird situation where the local being assigned to is also being used at its
+    // previous type implicitly in an rvalue position. This map provides the previous binding.
+    DenseHashMap<const AstExpr*, const Def*> compoundAssignDefs{nullptr};
+
     DenseHashMap<const AstExpr*, const RefinementKey*> astRefinementKeys{nullptr};
     friend struct DataFlowGraphBuilder;
 };

Analysis/include/Luau/FileResolver.h

@@ -1,9 +1,8 @@
 // This file is part of the Luau programming language and is licensed under MIT License; see LICENSE.txt for details
 #pragma once
 
-#include <memory>
-#include <optional>
 #include <string>
+#include <optional>
 #include <vector>
 
 namespace Luau
@@ -33,71 +32,15 @@ struct ModuleInfo
     bool optional = false;
 };
 
-struct RequireAlias
-{
-    std::string alias; // Unprefixed alias name (no leading `@`).
-    std::vector<std::string> tags = {};
-};
-
-struct RequireNode
-{
-    virtual ~RequireNode() {}
-
-    // Get the path component representing this node.
-    virtual std::string getPathComponent() const = 0;
-
-    // Get the displayed user-facing label for this node, defaults to getPathComponent()
-    virtual std::string getLabel() const
-    {
-        return getPathComponent();
-    }
-
-    // Get tags to attach to this node's RequireSuggestion (defaults to none).
-    virtual std::vector<std::string> getTags() const
-    {
-        return {};
-    }
-
-    // TODO: resolvePathToNode() can ultimately be replaced with a call into
-    // require-by-string's path resolution algorithm. This will first require
-    // generalizing that algorithm to work with a virtual file system.
-    virtual std::unique_ptr<RequireNode> resolvePathToNode(const std::string& path) const = 0;
-
-    // Get children of this node, if any (if this node represents a directory).
-    virtual std::vector<std::unique_ptr<RequireNode>> getChildren() const = 0;
-
-    // A list of the aliases available to this node.
-    virtual std::vector<RequireAlias> getAvailableAliases() const = 0;
-};
-
 struct RequireSuggestion
 {
     std::string label;
     std::string fullPath;
-    std::vector<std::string> tags;
 };
 using RequireSuggestions = std::vector<RequireSuggestion>;
 
-struct RequireSuggester
-{
-    virtual ~RequireSuggester() {}
-    std::optional<RequireSuggestions> getRequireSuggestions(const ModuleName& requirer, const std::optional<std::string>& pathString) const;
-
-protected:
-    virtual std::unique_ptr<RequireNode> getNode(const ModuleName& name) const = 0;
-
-private:
-    std::optional<RequireSuggestions> getRequireSuggestionsImpl(const ModuleName& requirer, const std::optional<std::string>& path) const;
-};
-
 struct FileResolver
 {
-    FileResolver() = default;
-    FileResolver(std::shared_ptr<RequireSuggester> requireSuggester)
-        : requireSuggester(std::move(requireSuggester))
-    {
-    }
-
     virtual ~FileResolver() {}
 
     virtual std::optional<SourceCode> readSource(const ModuleName& name) = 0;
@@ -117,10 +60,10 @@ struct FileResolver
         return std::nullopt;
     }
 
-    // Make non-virtual when removing FFlagLuauImproveRequireByStringAutocomplete.
-    virtual std::optional<RequireSuggestions> getRequireSuggestions(const ModuleName& requirer, const std::optional<std::string>& pathString) const;
-
-    std::shared_ptr<RequireSuggester> requireSuggester;
+    virtual std::optional<RequireSuggestions> getRequireSuggestions(const ModuleName& requirer, const std::optional<std::string>& pathString) const
+    {
+        return std::nullopt;
+    }
 };
 
 struct NullFileResolver : FileResolver

Analysis/include/Luau/FragmentAutocomplete.h

@@ -15,28 +15,6 @@ namespace Luau
 {
 struct FrontendOptions;
 
-enum class FragmentAutocompleteWaypoint
-{
-    ParseFragmentEnd,
-    CloneModuleStart,
-    CloneModuleEnd,
-    DfgBuildEnd,
-    CloneAndSquashScopeStart,
-    CloneAndSquashScopeEnd,
-    ConstraintSolverStart,
-    ConstraintSolverEnd,
-    TypecheckFragmentEnd,
-    AutocompleteEnd,
-    COUNT,
-};
-
-class IFragmentAutocompleteReporter
-{
-public:
-    virtual void reportWaypoint(FragmentAutocompleteWaypoint) = 0;
-    virtual void reportFragmentString(std::string_view) = 0;
-};
-
 enum class FragmentTypeCheckStatus
 {
     SkipAutocomplete,
@@ -49,8 +27,6 @@ struct FragmentAutocompleteAncestryResult
     std::vector<AstLocal*> localStack;
     std::vector<AstNode*> ancestry;
     AstStat* nearestStatement = nullptr;
-    AstStatBlock* parentBlock = nullptr;
-    Location fragmentSelectionRegion;
 };
 
 struct FragmentParseResult
@@ -61,7 +37,6 @@ struct FragmentParseResult
     AstStat* nearestStatement = nullptr;
     std::vector<Comment> commentLocations;
     std::unique_ptr<Allocator> alloc = std::make_unique<Allocator>();
-    Position scopePos{0, 0};
 };
 
 struct FragmentTypeCheckResult
@@ -79,29 +54,10 @@ struct FragmentAutocompleteResult
     AutocompleteResult acResults;
 };
 
-struct FragmentRegion
-{
-    Location fragmentLocation;
-    AstStat* nearestStatement = nullptr; // used for tests
-    AstStatBlock* parentBlock = nullptr; // used for scope detection
-};
-
-FragmentRegion getFragmentRegion(AstStatBlock* root, const Position& cursorPosition);
-FragmentAutocompleteAncestryResult findAncestryForFragmentParse(AstStatBlock* stale, const Position& cursorPos, AstStatBlock* lastGoodParse);
-FragmentAutocompleteAncestryResult findAncestryForFragmentParse_DEPRECATED(AstStatBlock* root, const Position& cursorPos);
-
-std::optional<FragmentParseResult> parseFragment_DEPRECATED(
-    AstStatBlock* root,
-    AstNameTable* names,
-    std::string_view src,
-    const Position& cursorPos,
-    std::optional<Position> fragmentEndPosition
-);
+FragmentAutocompleteAncestryResult findAncestryForFragmentParse(AstStatBlock* root, const Position& cursorPos);
 
 std::optional<FragmentParseResult> parseFragment(
-    AstStatBlock* stale,
-    AstStatBlock* mostRecentParse,
-    AstNameTable* names,
+    const SourceModule& srcModule,
     std::string_view src,
     const Position& cursorPos,
     std::optional<Position> fragmentEndPosition
@@ -113,9 +69,7 @@ std::pair<FragmentTypeCheckStatus, FragmentTypeCheckResult> typecheckFragment(
     const Position& cursorPos,
     std::optional<FrontendOptions> opts,
     std::string_view src,
-    std::optional<Position> fragmentEndPosition,
-    AstStatBlock* recentParse = nullptr,
-    IFragmentAutocompleteReporter* reporter = nullptr
+    std::optional<Position> fragmentEndPosition
 );
 
 FragmentAutocompleteResult fragmentAutocomplete(
@@ -125,71 +79,8 @@ FragmentAutocompleteResult fragmentAutocomplete(
     Position cursorPosition,
     std::optional<FrontendOptions> opts,
     StringCompletionCallback callback,
-    std::optional<Position> fragmentEndPosition = std::nullopt,
-    AstStatBlock* recentParse = nullptr,
-    IFragmentAutocompleteReporter* reporter = nullptr
+    std::optional<Position> fragmentEndPosition = std::nullopt
 );
 
-enum class FragmentAutocompleteStatus
-{
-    Success,
-    FragmentTypeCheckFail,
-    InternalIce
-};
-
-struct FragmentAutocompleteStatusResult
-{
-    FragmentAutocompleteStatus status;
-    std::optional<FragmentAutocompleteResult> result;
-};
-
-struct FragmentContext
-{
-    std::string_view newSrc;
-    const ParseResult& freshParse;
-    std::optional<FrontendOptions> opts;
-    std::optional<Position> DEPRECATED_fragmentEndPosition;
-    IFragmentAutocompleteReporter* reporter = nullptr;
-};
-
-/**
- * @brief Attempts to compute autocomplete suggestions from the fragment context.
- *
- * This function computes autocomplete suggestions using outdated frontend typechecking data
- * by patching the fragment context of the new script source content.
- *
- * @param frontend The Luau Frontend data structure, which may contain outdated typechecking data.
- *
- * @param moduleName The name of the target module, specifying which script the caller wants to request autocomplete for.
- *
- * @param cursorPosition The position in the script where the caller wants to trigger autocomplete.
- *
- * @param context The fragment context that this API will use to patch the outdated typechecking data.
- *
- * @param stringCompletionCB A callback function that provides autocomplete suggestions for string contexts.
- *
- * @return
- * The status indicating whether `fragmentAutocomplete` ran successfully or failed, along with the reason for failure.
- * Also includes autocomplete suggestions if the status is successful.
- *
- * @usage
- * FragmentAutocompleteStatusResult acStatusResult;
- * if (shouldFragmentAC)
- *     acStatusResult = Luau::tryFragmentAutocomplete(...);
- *
- * if (acStatusResult.status != Successful)
- * {
- *     frontend.check(moduleName, options);
- *     acStatusResult.acResult = Luau::autocomplete(...);
- * }
- * return convertResultWithContext(acStatusResult.acResult);
- */
-FragmentAutocompleteStatusResult tryFragmentAutocomplete(
-    Frontend& frontend,
-    const ModuleName& moduleName,
-    Position cursorPosition,
-    FragmentContext context,
-    StringCompletionCallback stringCompletionCB
-);
 
 } // namespace Luau

Analysis/include/Luau/Frontend.h

@@ -10,6 +10,7 @@
 #include "Luau/Set.h"
 #include "Luau/TypeCheckLimits.h"
 #include "Luau/Variant.h"
+#include "Luau/AnyTypeSummary.h"
 
 #include <mutex>
 #include <string>
@@ -31,8 +32,8 @@ struct ModuleResolver;
 struct ParseResult;
 struct HotComment;
 struct BuildQueueItem;
-struct BuildQueueWorkState;
 struct FrontendCancellationToken;
+struct AnyTypeSummary;
 
 struct LoadDefinitionFileResult
 {
@@ -215,11 +216,6 @@ struct Frontend
         std::function<void(std::function<void()> task)> executeTask = {},
         std::function<bool(size_t done, size_t total)> progress = {}
     );
-    std::vector<ModuleName> checkQueuedModules_DEPRECATED(
-        std::optional<FrontendOptions> optionOverride = {},
-        std::function<void(std::function<void()> task)> executeTask = {},
-        std::function<bool(size_t done, size_t total)> progress = {}
-    );
 
     std::optional<CheckResult> getCheckResult(const ModuleName& name, bool accumulateNested, bool forAutocomplete = false);
     std::vector<ModuleName> getRequiredScripts(const ModuleName& name);
@@ -255,9 +251,6 @@ private:
     void checkBuildQueueItem(BuildQueueItem& item);
     void checkBuildQueueItems(std::vector<BuildQueueItem>& items);
     void recordItemResult(const BuildQueueItem& item);
-    void performQueueItemTask(std::shared_ptr<BuildQueueWorkState> state, size_t itemPos);
-    void sendQueueItemTask(std::shared_ptr<BuildQueueWorkState> state, size_t itemPos);
-    void sendQueueCycleItemTask(std::shared_ptr<BuildQueueWorkState> state);
 
     static LintResult classifyLints(const std::vector<LintWarning>& warnings, const Config& config);
 
@@ -303,7 +296,6 @@ ModulePtr check(
     NotNull<ModuleResolver> moduleResolver,
     NotNull<FileResolver> fileResolver,
     const ScopePtr& globalScope,
-    const ScopePtr& typeFunctionScope,
     std::function<void(const ModuleName&, const ScopePtr&)> prepareModuleScope,
     FrontendOptions options,
     TypeCheckLimits limits
@@ -318,7 +310,6 @@ ModulePtr check(
     NotNull<ModuleResolver> moduleResolver,
     NotNull<FileResolver> fileResolver,
     const ScopePtr& globalScope,
-    const ScopePtr& typeFunctionScope,
     std::function<void(const ModuleName&, const ScopePtr&)> prepareModuleScope,
     FrontendOptions options,
     TypeCheckLimits limits,

Analysis/include/Luau/Generalization.h

@@ -12,8 +12,8 @@ std::optional<TypeId> generalize(
     NotNull<TypeArena> arena,
     NotNull<BuiltinTypes> builtinTypes,
     NotNull<Scope> scope,
-    NotNull<DenseHashSet<TypeId>> cachedTypes,
-    TypeId ty
+    NotNull<DenseHashSet<TypeId>> bakedTypes,
+    TypeId ty,
+    /* avoid sealing tables*/ bool avoidSealingTables = false
 );
-
 }

Analysis/include/Luau/GlobalTypes.h

@@ -19,9 +19,7 @@ struct GlobalTypes
 
     TypeArena globalTypes;
     SourceModule globalNames; // names for symbols entered into globalScope
-
     ScopePtr globalScope;     // shared by all modules
-    ScopePtr globalTypeFunctionScope; // shared by all modules
 };
 
 } // namespace Luau

Analysis/include/Luau/Module.h

@@ -8,6 +8,7 @@
 #include "Luau/ParseResult.h"
 #include "Luau/Scope.h"
 #include "Luau/TypeArena.h"
+#include "Luau/AnyTypeSummary.h"
 #include "Luau/DataFlowGraph.h"
 
 #include <memory>
@@ -20,13 +21,14 @@ LUAU_FASTFLAG(LuauIncrementalAutocompleteCommentDetection)
 namespace Luau
 {
 
-using LogLuauProc = void (*)(std::string_view, std::string_view);
+using LogLuauProc = void (*)(std::string_view);
 extern LogLuauProc logLuau;
 
 void setLogLuau(LogLuauProc ll);
 void resetLogLuauProc();
 
 struct Module;
+struct AnyTypeSummary;
 
 using ScopePtr = std::shared_ptr<struct Scope>;
 using ModulePtr = std::shared_ptr<Module>;
@@ -84,10 +86,13 @@ struct Module
     TypeArena interfaceTypes;
     TypeArena internalTypes;
 
+    // Summary of Ast Nodes that either contain
+    // user annotated anys or typechecker inferred anys
+    AnyTypeSummary ats{};
+
     // Scopes and AST types refer to parse data, so we need to keep that alive
     std::shared_ptr<Allocator> allocator;
     std::shared_ptr<AstNameTable> names;
-    AstStatBlock* root = nullptr;
 
     std::vector<std::pair<Location, ScopePtr>> scopes; // never empty
 

Analysis/include/Luau/NonStrictTypeChecker.h

@@ -1,10 +1,9 @@
 // This file is part of the Luau programming language and is licensed under MIT License; see LICENSE.txt for details
 #pragma once
 
-#include "Luau/DataFlowGraph.h"
-#include "Luau/EqSatSimplification.h"
 #include "Luau/Module.h"
 #include "Luau/NotNull.h"
+#include "Luau/DataFlowGraph.h"
 
 namespace Luau
 {

Analysis/include/Luau/Quantify.h

@@ -31,4 +31,13 @@ struct OrderedMap
     }
 };
 
+struct QuantifierResult
+{
+    TypeId result;
+    OrderedMap<TypeId, TypeId> insertedGenerics;
+    OrderedMap<TypePackId, TypePackId> insertedGenericPacks;
+};
+
+std::optional<QuantifierResult> quantify(TypeArena* arena, TypeId ty, Scope* scope);
+
 } // namespace Luau

Analysis/include/Luau/Refinement.h

@@ -53,7 +53,6 @@ struct Proposition
 {
     const RefinementKey* key;
     TypeId discriminantTy;
-    bool implicitFromCall;
 };
 
 template<typename T>
@@ -70,7 +69,6 @@ struct RefinementArena
     RefinementId disjunction(RefinementId lhs, RefinementId rhs);
     RefinementId equivalence(RefinementId lhs, RefinementId rhs);
     RefinementId proposition(const RefinementKey* key, TypeId discriminantTy);
-    RefinementId implicitProposition(const RefinementKey* key, TypeId discriminantTy);
 
 private:
     TypedAllocator<Refinement> allocator;

Analysis/include/Luau/Scope.h

@@ -35,7 +35,7 @@ struct Scope
     explicit Scope(TypePackId returnType);                    // root scope
     explicit Scope(const ScopePtr& parent, int subLevel = 0); // child scope.  Parent must not be nullptr.
 
-    ScopePtr parent; // null for the root
+    const ScopePtr parent; // null for the root
 
     // All the children of this scope.
     std::vector<NotNull<Scope>> children;
@@ -59,8 +59,6 @@ struct Scope
 
     std::optional<TypeId> lookup(Symbol sym) const;
     std::optional<TypeId> lookupUnrefinedType(DefId def) const;
-
-    std::optional<TypeId> lookupRValueRefinementType(DefId def) const;
     std::optional<TypeId> lookup(DefId def) const;
     std::optional<std::pair<TypeId, Scope*>> lookupEx(DefId def);
     std::optional<std::pair<Binding*, Scope*>> lookupEx(Symbol sym);
@@ -73,7 +71,6 @@ struct Scope
 
     // WARNING: This function linearly scans for a string key of equal value!  It is thus O(n**2)
     std::optional<Binding> linearSearchForBinding(const std::string& name, bool traverseScopeChain = true) const;
-    std::optional<std::pair<Symbol, Binding>> linearSearchForBindingPair(const std::string& name, bool traverseScopeChain) const;
 
     RefinementMap refinements;
 

Analysis/include/Luau/TableLiteralInference.h

@@ -6,15 +6,12 @@
 #include "Luau/NotNull.h"
 #include "Luau/TypeFwd.h"
 
-#include <vector>
-
 namespace Luau
 {
 
 struct TypeArena;
 struct BuiltinTypes;
 struct Unifier2;
-struct Subtyping;
 class AstExpr;
 
 TypeId matchLiteralType(
@@ -23,7 +20,6 @@ TypeId matchLiteralType(
     NotNull<BuiltinTypes> builtinTypes,
     NotNull<TypeArena> arena,
     NotNull<Unifier2> unifier,
-    NotNull<Subtyping> subtyping,
     TypeId expectedType,
     TypeId exprType,
     const AstExpr* expr,

Analysis/include/Luau/TxnLog.h

@@ -65,10 +65,11 @@ T* getMutable(PendingTypePack* pending)
 // Log of what TypeIds we are rebinding, to be committed later.
 struct TxnLog
 {
-    explicit TxnLog()
+    explicit TxnLog(bool useScopes = false)
         : typeVarChanges(nullptr)
         , typePackChanges(nullptr)
         , ownedSeen()
+        , useScopes(useScopes)
         , sharedSeen(&ownedSeen)
     {
     }

Analysis/include/Luau/Type.h

@@ -19,6 +19,7 @@
 #include <optional>
 #include <set>
 #include <string>
+#include <unordered_map>
 #include <vector>
 
 LUAU_FASTINT(LuauTableTypeMaximumStringifierLength)
@@ -37,15 +38,6 @@ struct Constraint;
 struct Subtyping;
 struct TypeChecker2;
 
-enum struct Polarity : uint8_t
-{
-    None = 0b000,
-    Positive = 0b001,
-    Negative = 0b010,
-    Mixed = 0b011,
-    Unknown = 0b100,
-};
-
 /**
  * There are three kinds of type variables:
  * - `Free` variables are metavariables, which stand for unconstrained types.
@@ -404,7 +396,6 @@ struct FunctionType
     // this flag is used as an optimization to exit early from procedures that manipulate free or generic types.
     bool hasNoFreeOrGenericTypes = false;
     bool isCheckedFunction = false;
-    bool isDeprecatedFunction = false;
 };
 
 enum class TableState
@@ -631,6 +622,7 @@ struct UserDefinedFunctionData
     AstStatTypeFunction* definition = nullptr;
 
     DenseHashMap<Name, std::pair<AstStatTypeFunction*, size_t>> environment{""};
+    DenseHashMap<Name, AstStatTypeFunction*> environment_DEPRECATED{""};
 };
 
 /**

Analysis/include/Luau/TypeChecker2.h

@@ -13,8 +13,6 @@
 #include "Luau/TypeOrPack.h"
 #include "Luau/TypeUtils.h"
 
-LUAU_FASTFLAG(LuauImproveTypePathsInErrors)
-
 namespace Luau
 {
 
@@ -40,29 +38,18 @@ struct Reasonings
 
     std::string toString()
     {
-        if (FFlag::LuauImproveTypePathsInErrors && reasons.empty())
-            return "";
-
         // DenseHashSet ordering is entirely undefined, so we want to
         // sort the reasons here to achieve a stable error
         // stringification.
         std::sort(reasons.begin(), reasons.end());
-        std::string allReasons = FFlag::LuauImproveTypePathsInErrors ? "\nthis is because " : "";
+        std::string allReasons;
         bool first = true;
         for (const std::string& reason : reasons)
         {
-            if (FFlag::LuauImproveTypePathsInErrors)
-            {
-                if (reasons.size() > 1)
-                    allReasons += "\n\t * ";
-            }
+            if (first)
+                first = false;
             else
-            {
-                if (first)
-                    first = false;
-                else
-                    allReasons += "\n\t";
-            }
+                allReasons += "\n\t";
 
             allReasons += reason;
         }

Analysis/include/Luau/TypeFunction.h

@@ -48,9 +48,6 @@ struct TypeFunctionRuntime
     // Evaluation of type functions should only be performed in the absence of parse errors in the source module
     bool allowEvaluation = true;
 
-    // Root scope in which the type function operates in, set up by ConstraintGenerator
-    ScopePtr rootScope;
-
     // Output created by 'print' function
     std::vector<std::string> messages;
 
@@ -177,7 +174,6 @@ struct FunctionGraphReductionResult
     DenseHashSet<TypePackId> blockedPacks{nullptr};
     DenseHashSet<TypeId> reducedTypes{nullptr};
     DenseHashSet<TypePackId> reducedPacks{nullptr};
-    DenseHashSet<TypeId> irreducibleTypes{nullptr};
 };
 
 /**

Analysis/include/Luau/TypeFunctionRuntime.h

@@ -216,13 +216,11 @@ struct TypeFunctionClassType
 
     std::optional<TypeFunctionTypeId> metatable; // metaclass?
 
-    // this was mistaken, and we should actually be keeping separate read/write types here.
-    std::optional<TypeFunctionTypeId> parent_DEPRECATED;
-
-    std::optional<TypeFunctionTypeId> readParent;
-    std::optional<TypeFunctionTypeId> writeParent;
+    std::optional<TypeFunctionTypeId> parent;
 
     TypeId classTy;
+
+    std::string name_DEPRECATED;
 };
 
 struct TypeFunctionGenericType

Analysis/include/Luau/TypeFunctionRuntimeBuilder.h

@@ -28,8 +28,14 @@ struct TypeFunctionRuntimeBuilderState
 {
     NotNull<TypeFunctionContext> ctx;
 
+    // Mapping of class name to ClassType
+    // Invariant: users can not create a new class types -> any class types that get deserialized must have been an argument to the type function
+    // Using this invariant, whenever a ClassType is serialized, we can put it into this map
+    // whenever a ClassType is deserialized, we can use this map to return the corresponding value
+    DenseHashMap<std::string, TypeId> classesSerialized_DEPRECATED{{}};
+
     // List of errors that occur during serialization/deserialization
-    // At every iteration of serialization/deserialization, if this list.size() != 0, we halt the process
+    // At every iteration of serialization/deserialzation, if this list.size() != 0, we halt the process
     std::vector<std::string> errors{};
 
     TypeFunctionRuntimeBuilderState(NotNull<TypeFunctionContext> ctx)

Analysis/include/Luau/TypePath.h

@@ -42,19 +42,9 @@ struct Property
 /// element.
 struct Index
 {
-    enum class Variant
-    {
-        Pack,
-        Union,
-        Intersection
-    };
-
     /// The 0-based index to use for the lookup.
     size_t index;
 
-    /// The sort of thing we're indexing from, this is used in stringifying the type path for errors.
-    Variant variant;
-
     bool operator==(const Index& other) const;
 };
 
@@ -215,9 +205,6 @@ using Path = TypePath::Path;
 /// terribly clear to end users of the Luau type system.
 std::string toString(const TypePath::Path& path, bool prefixDot = false);
 
-/// Converts a Path to a human readable string for error reporting.
-std::string toStringHuman(const TypePath::Path& path);
-
 std::optional<TypeOrPack> traverse(TypeId root, const Path& path, NotNull<BuiltinTypes> builtinTypes);
 std::optional<TypeOrPack> traverse(TypePackId root, const Path& path, NotNull<BuiltinTypes> builtinTypes);
 

Analysis/include/Luau/Unifier.h

@@ -93,6 +93,10 @@ struct Unifier
 
     Unifier(NotNull<Normalizer> normalizer, NotNull<Scope> scope, const Location& location, Variance variance, TxnLog* parentLog = nullptr);
 
+    // Configure the Unifier to test for scope subsumption via embedded Scope
+    // pointers rather than TypeLevels.
+    void enableNewSolver();
+
     // Test whether the two type vars unify.  Never commits the result.
     ErrorVec canUnify(TypeId subTy, TypeId superTy);
     ErrorVec canUnify(TypePackId subTy, TypePackId superTy, bool isFunctionCall = false);
@@ -165,6 +169,7 @@ private:
 
     std::optional<TypeId> findTablePropertyRespectingMeta(TypeId lhsType, Name name);
 
+    TxnLog combineLogsIntoIntersection(std::vector<TxnLog> logs);
     TxnLog combineLogsIntoUnion(std::vector<TxnLog> logs);
 
 public:
@@ -190,6 +195,11 @@ private:
 
     // Available after regular type pack unification errors
     std::optional<int> firstPackErrorPos;
+
+    // If true, we do a bunch of small things differently to work better with
+    // the new type inference engine. Most notably, we use the Scope hierarchy
+    // directly rather than using TypeLevels.
+    bool useNewSolver = false;
 };
 
 void promoteTypeLevels(TxnLog& log, const TypeArena* arena, TypeLevel minLevel, Scope* outerScope, bool useScope, TypePackId tp);

Analysis/include/Luau/Unifier2.h

@@ -87,9 +87,6 @@ struct Unifier2
     bool unify(const AnyType* subAny, const TableType* superTable);
     bool unify(const TableType* subTable, const AnyType* superAny);
 
-    bool unify(const MetatableType* subMetatable, const AnyType*);
-    bool unify(const AnyType*, const MetatableType* superMetatable);
-
     // TODO think about this one carefully.  We don't do unions or intersections of type packs
     bool unify(TypePackId subTp, TypePackId superTp);
 

Analysis/src/AnyTypeSummary.cpp

@@ -0,0 +1,902 @@
+// This file is part of the Luau programming language and is licensed under MIT License; see LICENSE.txt for details
+#include "Luau/AnyTypeSummary.h"
+
+#include "Luau/BuiltinDefinitions.h"
+#include "Luau/Clone.h"
+#include "Luau/Common.h"
+#include "Luau/Config.h"
+#include "Luau/ConstraintGenerator.h"
+#include "Luau/ConstraintSolver.h"
+#include "Luau/DataFlowGraph.h"
+#include "Luau/DcrLogger.h"
+#include "Luau/Module.h"
+#include "Luau/Parser.h"
+#include "Luau/Scope.h"
+#include "Luau/StringUtils.h"
+#include "Luau/TimeTrace.h"
+#include "Luau/ToString.h"
+#include "Luau/Transpiler.h"
+#include "Luau/TypeArena.h"
+#include "Luau/TypeChecker2.h"
+#include "Luau/NonStrictTypeChecker.h"
+#include "Luau/TypeInfer.h"
+#include "Luau/Variant.h"
+#include "Luau/VisitType.h"
+#include "Luau/TypePack.h"
+#include "Luau/TypeOrPack.h"
+
+#include <algorithm>
+#include <memory>
+#include <chrono>
+#include <condition_variable>
+#include <exception>
+#include <mutex>
+#include <stdexcept>
+#include <string>
+#include <iostream>
+
+
+#include <stdio.h>
+
+LUAU_FASTFLAGVARIABLE(StudioReportLuauAny2);
+LUAU_FASTINTVARIABLE(LuauAnySummaryRecursionLimit, 300);
+
+LUAU_FASTFLAG(DebugLuauMagicTypes);
+
+namespace Luau
+{
+
+void AnyTypeSummary::traverse(const Module* module, AstStat* src, NotNull<BuiltinTypes> builtinTypes)
+{
+    visit(findInnerMostScope(src->location, module), src, module, builtinTypes);
+}
+
+void AnyTypeSummary::visit(const Scope* scope, AstStat* stat, const Module* module, NotNull<BuiltinTypes> builtinTypes)
+{
+    RecursionLimiter limiter{&recursionCount, FInt::LuauAnySummaryRecursionLimit};
+
+    if (auto s = stat->as<AstStatBlock>())
+        return visit(scope, s, module, builtinTypes);
+    else if (auto i = stat->as<AstStatIf>())
+        return visit(scope, i, module, builtinTypes);
+    else if (auto s = stat->as<AstStatWhile>())
+        return visit(scope, s, module, builtinTypes);
+    else if (auto s = stat->as<AstStatRepeat>())
+        return visit(scope, s, module, builtinTypes);
+    else if (auto r = stat->as<AstStatReturn>())
+        return visit(scope, r, module, builtinTypes);
+    else if (auto e = stat->as<AstStatExpr>())
+        return visit(scope, e, module, builtinTypes);
+    else if (auto s = stat->as<AstStatLocal>())
+        return visit(scope, s, module, builtinTypes);
+    else if (auto s = stat->as<AstStatFor>())
+        return visit(scope, s, module, builtinTypes);
+    else if (auto s = stat->as<AstStatForIn>())
+        return visit(scope, s, module, builtinTypes);
+    else if (auto a = stat->as<AstStatAssign>())
+        return visit(scope, a, module, builtinTypes);
+    else if (auto a = stat->as<AstStatCompoundAssign>())
+        return visit(scope, a, module, builtinTypes);
+    else if (auto f = stat->as<AstStatFunction>())
+        return visit(scope, f, module, builtinTypes);
+    else if (auto f = stat->as<AstStatLocalFunction>())
+        return visit(scope, f, module, builtinTypes);
+    else if (auto a = stat->as<AstStatTypeAlias>())
+        return visit(scope, a, module, builtinTypes);
+    else if (auto s = stat->as<AstStatDeclareGlobal>())
+        return visit(scope, s, module, builtinTypes);
+    else if (auto s = stat->as<AstStatDeclareFunction>())
+        return visit(scope, s, module, builtinTypes);
+    else if (auto s = stat->as<AstStatDeclareClass>())
+        return visit(scope, s, module, builtinTypes);
+    else if (auto s = stat->as<AstStatError>())
+        return visit(scope, s, module, builtinTypes);
+}
+
+void AnyTypeSummary::visit(const Scope* scope, AstStatBlock* block, const Module* module, NotNull<BuiltinTypes> builtinTypes)
+{
+    RecursionCounter counter{&recursionCount};
+
+    if (recursionCount >= FInt::LuauAnySummaryRecursionLimit)
+        return; // don't report
+
+    for (AstStat* stat : block->body)
+        visit(scope, stat, module, builtinTypes);
+}
+
+void AnyTypeSummary::visit(const Scope* scope, AstStatIf* ifStatement, const Module* module, NotNull<BuiltinTypes> builtinTypes)
+{
+    if (ifStatement->thenbody)
+    {
+        const Scope* thenScope = findInnerMostScope(ifStatement->thenbody->location, module);
+        visit(thenScope, ifStatement->thenbody, module, builtinTypes);
+    }
+
+    if (ifStatement->elsebody)
+    {
+        const Scope* elseScope = findInnerMostScope(ifStatement->elsebody->location, module);
+        visit(elseScope, ifStatement->elsebody, module, builtinTypes);
+    }
+}
+
+void AnyTypeSummary::visit(const Scope* scope, AstStatWhile* while_, const Module* module, NotNull<BuiltinTypes> builtinTypes)
+{
+    const Scope* whileScope = findInnerMostScope(while_->location, module);
+    visit(whileScope, while_->body, module, builtinTypes);
+}
+
+void AnyTypeSummary::visit(const Scope* scope, AstStatRepeat* repeat, const Module* module, NotNull<BuiltinTypes> builtinTypes)
+{
+    const Scope* repeatScope = findInnerMostScope(repeat->location, module);
+    visit(repeatScope, repeat->body, module, builtinTypes);
+}
+
+void AnyTypeSummary::visit(const Scope* scope, AstStatReturn* ret, const Module* module, NotNull<BuiltinTypes> builtinTypes)
+{
+    const Scope* retScope = findInnerMostScope(ret->location, module);
+
+    auto ctxNode = getNode(rootSrc, ret);
+    bool seenTP = false;
+
+    for (auto val : ret->list)
+    {
+        if (isAnyCall(retScope, val, module, builtinTypes))
+        {
+            TelemetryTypePair types;
+            types.inferredType = toString(lookupType(val, module, builtinTypes));
+            TypeInfo ti{Pattern::FuncApp, toString(ctxNode), types};
+            typeInfo.push_back(ti);
+        }
+
+        if (isAnyCast(retScope, val, module, builtinTypes))
+        {
+            if (auto cast = val->as<AstExprTypeAssertion>())
+            {
+                TelemetryTypePair types;
+
+                types.annotatedType = toString(lookupAnnotation(cast->annotation, module, builtinTypes));
+                types.inferredType = toString(lookupType(cast->expr, module, builtinTypes));
+
+                TypeInfo ti{Pattern::Casts, toString(ctxNode), types};
+                typeInfo.push_back(ti);
+            }
+        }
+
+        if (ret->list.size > 1 && !seenTP)
+        {
+            if (containsAny(retScope->returnType))
+            {
+                seenTP = true;
+
+                TelemetryTypePair types;
+
+                types.inferredType = toString(retScope->returnType);
+
+                TypeInfo ti{Pattern::TypePk, toString(ctxNode), types};
+                typeInfo.push_back(ti);
+            }
+        }
+    }
+}
+
+void AnyTypeSummary::visit(const Scope* scope, AstStatLocal* local, const Module* module, NotNull<BuiltinTypes> builtinTypes)
+{
+    auto ctxNode = getNode(rootSrc, local);
+
+    TypePackId values = reconstructTypePack(local->values, module, builtinTypes);
+    auto [head, tail] = flatten(values);
+
+    size_t posn = 0;
+    for (AstLocal* loc : local->vars)
+    {
+        if (local->vars.data[0] == loc && posn < local->values.size)
+        {
+            if (loc->annotation)
+            {
+                auto annot = lookupAnnotation(loc->annotation, module, builtinTypes);
+                if (containsAny(annot))
+                {
+                    TelemetryTypePair types;
+
+                    types.annotatedType = toString(annot);
+                    types.inferredType = toString(lookupType(local->values.data[posn], module, builtinTypes));
+
+                    TypeInfo ti{Pattern::VarAnnot, toString(ctxNode), types};
+                    typeInfo.push_back(ti);
+                }
+            }
+
+            const AstExprTypeAssertion* maybeRequire = local->values.data[posn]->as<AstExprTypeAssertion>();
+            if (!maybeRequire)
+                continue;
+
+            if (std::min(local->values.size - 1, posn) < head.size())
+            {
+                if (isAnyCast(scope, local->values.data[posn], module, builtinTypes))
+                {
+                    TelemetryTypePair types;
+
+                    types.inferredType = toString(head[std::min(local->values.size - 1, posn)]);
+
+                    TypeInfo ti{Pattern::Casts, toString(ctxNode), types};
+                    typeInfo.push_back(ti);
+                }
+            }
+        }
+        else
+        {
+
+            if (std::min(local->values.size - 1, posn) < head.size())
+            {
+                if (loc->annotation)
+                {
+                    auto annot = lookupAnnotation(loc->annotation, module, builtinTypes);
+                    if (containsAny(annot))
+                    {
+                        TelemetryTypePair types;
+
+                        types.annotatedType = toString(annot);
+                        types.inferredType = toString(head[std::min(local->values.size - 1, posn)]);
+
+                        TypeInfo ti{Pattern::VarAnnot, toString(ctxNode), types};
+                        typeInfo.push_back(ti);
+                    }
+                }
+            }
+            else
+            {
+                if (tail)
+                {
+                    if (containsAny(*tail))
+                    {
+                        TelemetryTypePair types;
+
+                        types.inferredType = toString(*tail);
+
+                        TypeInfo ti{Pattern::VarAny, toString(ctxNode), types};
+                        typeInfo.push_back(ti);
+                    }
+                }
+            }
+        }
+
+        ++posn;
+    }
+}
+
+void AnyTypeSummary::visit(const Scope* scope, AstStatFor* for_, const Module* module, NotNull<BuiltinTypes> builtinTypes)
+{
+    const Scope* forScope = findInnerMostScope(for_->location, module);
+    visit(forScope, for_->body, module, builtinTypes);
+}
+
+void AnyTypeSummary::visit(const Scope* scope, AstStatForIn* forIn, const Module* module, NotNull<BuiltinTypes> builtinTypes)
+{
+    const Scope* loopScope = findInnerMostScope(forIn->location, module);
+    visit(loopScope, forIn->body, module, builtinTypes);
+}
+
+void AnyTypeSummary::visit(const Scope* scope, AstStatAssign* assign, const Module* module, NotNull<BuiltinTypes> builtinTypes)
+{
+    auto ctxNode = getNode(rootSrc, assign);
+
+    TypePackId values = reconstructTypePack(assign->values, module, builtinTypes);
+    auto [head, tail] = flatten(values);
+
+    size_t posn = 0;
+    for (AstExpr* var : assign->vars)
+    {
+        TypeId tp = lookupType(var, module, builtinTypes);
+        if (containsAny(tp))
+        {
+            TelemetryTypePair types;
+
+            types.annotatedType = toString(tp);
+
+            auto loc = std::min(assign->vars.size - 1, posn);
+            if (head.size() >= assign->vars.size && posn < head.size())
+            {
+                types.inferredType = toString(head[posn]);
+            }
+            else if (loc < head.size())
+                types.inferredType = toString(head[loc]);
+            else
+                types.inferredType = toString(builtinTypes->nilType);
+
+            TypeInfo ti{Pattern::Assign, toString(ctxNode), types};
+            typeInfo.push_back(ti);
+        }
+        ++posn;
+    }
+
+    for (AstExpr* val : assign->values)
+    {
+        if (isAnyCall(scope, val, module, builtinTypes))
+        {
+            TelemetryTypePair types;
+
+            types.inferredType = toString(lookupType(val, module, builtinTypes));
+
+            TypeInfo ti{Pattern::FuncApp, toString(ctxNode), types};
+            typeInfo.push_back(ti);
+        }
+
+        if (isAnyCast(scope, val, module, builtinTypes))
+        {
+            if (auto cast = val->as<AstExprTypeAssertion>())
+            {
+                TelemetryTypePair types;
+
+                types.annotatedType = toString(lookupAnnotation(cast->annotation, module, builtinTypes));
+                types.inferredType = toString(lookupType(val, module, builtinTypes));
+
+                TypeInfo ti{Pattern::Casts, toString(ctxNode), types};
+                typeInfo.push_back(ti);
+            }
+        }
+    }
+
+    if (tail)
+    {
+        if (containsAny(*tail))
+        {
+            TelemetryTypePair types;
+
+            types.inferredType = toString(*tail);
+
+            TypeInfo ti{Pattern::Assign, toString(ctxNode), types};
+            typeInfo.push_back(ti);
+        }
+    }
+}
+
+void AnyTypeSummary::visit(const Scope* scope, AstStatCompoundAssign* assign, const Module* module, NotNull<BuiltinTypes> builtinTypes)
+{
+    auto ctxNode = getNode(rootSrc, assign);
+
+    TelemetryTypePair types;
+
+    types.inferredType = toString(lookupType(assign->value, module, builtinTypes));
+    types.annotatedType = toString(lookupType(assign->var, module, builtinTypes));
+
+    if (module->astTypes.contains(assign->var))
+    {
+        if (containsAny(*module->astTypes.find(assign->var)))
+        {
+            TypeInfo ti{Pattern::Assign, toString(ctxNode), types};
+            typeInfo.push_back(ti);
+        }
+    }
+    else if (module->astTypePacks.contains(assign->var))
+    {
+        if (containsAny(*module->astTypePacks.find(assign->var)))
+        {
+            TypeInfo ti{Pattern::Assign, toString(ctxNode), types};
+            typeInfo.push_back(ti);
+        }
+    }
+
+    if (isAnyCall(scope, assign->value, module, builtinTypes))
+    {
+        TypeInfo ti{Pattern::FuncApp, toString(ctxNode), types};
+        typeInfo.push_back(ti);
+    }
+
+    if (isAnyCast(scope, assign->value, module, builtinTypes))
+    {
+        if (auto cast = assign->value->as<AstExprTypeAssertion>())
+        {
+            types.annotatedType = toString(lookupAnnotation(cast->annotation, module, builtinTypes));
+            types.inferredType = toString(lookupType(cast->expr, module, builtinTypes));
+
+            TypeInfo ti{Pattern::Casts, toString(ctxNode), types};
+            typeInfo.push_back(ti);
+        }
+    }
+}
+
+void AnyTypeSummary::visit(const Scope* scope, AstStatFunction* function, const Module* module, NotNull<BuiltinTypes> builtinTypes)
+{
+    TelemetryTypePair types;
+    types.inferredType = toString(lookupType(function->func, module, builtinTypes));
+
+    if (hasVariadicAnys(scope, function->func, module, builtinTypes))
+    {
+        TypeInfo ti{Pattern::VarAny, toString(function), types};
+        typeInfo.push_back(ti);
+    }
+
+    if (hasArgAnys(scope, function->func, module, builtinTypes))
+    {
+        TypeInfo ti{Pattern::FuncArg, toString(function), types};
+        typeInfo.push_back(ti);
+    }
+
+    if (hasAnyReturns(scope, function->func, module, builtinTypes))
+    {
+        TypeInfo ti{Pattern::FuncRet, toString(function), types};
+        typeInfo.push_back(ti);
+    }
+
+    if (function->func->body->body.size > 0)
+        visit(scope, function->func->body, module, builtinTypes);
+}
+
+void AnyTypeSummary::visit(const Scope* scope, AstStatLocalFunction* function, const Module* module, NotNull<BuiltinTypes> builtinTypes)
+{
+    TelemetryTypePair types;
+
+    if (hasVariadicAnys(scope, function->func, module, builtinTypes))
+    {
+        types.inferredType = toString(lookupType(function->func, module, builtinTypes));
+        TypeInfo ti{Pattern::VarAny, toString(function), types};
+        typeInfo.push_back(ti);
+    }
+
+    if (hasArgAnys(scope, function->func, module, builtinTypes))
+    {
+        types.inferredType = toString(lookupType(function->func, module, builtinTypes));
+        TypeInfo ti{Pattern::FuncArg, toString(function), types};
+        typeInfo.push_back(ti);
+    }
+
+    if (hasAnyReturns(scope, function->func, module, builtinTypes))
+    {
+        types.inferredType = toString(lookupType(function->func, module, builtinTypes));
+        TypeInfo ti{Pattern::FuncRet, toString(function), types};
+        typeInfo.push_back(ti);
+    }
+
+    if (function->func->body->body.size > 0)
+        visit(scope, function->func->body, module, builtinTypes);
+}
+
+void AnyTypeSummary::visit(const Scope* scope, AstStatTypeAlias* alias, const Module* module, NotNull<BuiltinTypes> builtinTypes)
+{
+    auto ctxNode = getNode(rootSrc, alias);
+
+    auto annot = lookupAnnotation(alias->type, module, builtinTypes);
+    if (containsAny(annot))
+    {
+        // no expr => no inference for aliases
+        TelemetryTypePair types;
+
+        types.annotatedType = toString(annot);
+        TypeInfo ti{Pattern::Alias, toString(ctxNode), types};
+        typeInfo.push_back(ti);
+    }
+}
+
+void AnyTypeSummary::visit(const Scope* scope, AstStatExpr* expr, const Module* module, NotNull<BuiltinTypes> builtinTypes)
+{
+    auto ctxNode = getNode(rootSrc, expr);
+
+    if (isAnyCall(scope, expr->expr, module, builtinTypes))
+    {
+        TelemetryTypePair types;
+        types.inferredType = toString(lookupType(expr->expr, module, builtinTypes));
+
+        TypeInfo ti{Pattern::FuncApp, toString(ctxNode), types};
+        typeInfo.push_back(ti);
+    }
+}
+
+void AnyTypeSummary::visit(const Scope* scope, AstStatDeclareGlobal* declareGlobal, const Module* module, NotNull<BuiltinTypes> builtinTypes) {}
+
+void AnyTypeSummary::visit(const Scope* scope, AstStatDeclareClass* declareClass, const Module* module, NotNull<BuiltinTypes> builtinTypes) {}
+
+void AnyTypeSummary::visit(const Scope* scope, AstStatDeclareFunction* declareFunction, const Module* module, NotNull<BuiltinTypes> builtinTypes) {}
+
+void AnyTypeSummary::visit(const Scope* scope, AstStatError* error, const Module* module, NotNull<BuiltinTypes> builtinTypes) {}
+
+TypeId AnyTypeSummary::checkForFamilyInhabitance(const TypeId instance, const Location location)
+{
+    if (seenTypeFamilyInstances.find(instance))
+        return instance;
+
+    seenTypeFamilyInstances.insert(instance);
+    return instance;
+}
+
+TypeId AnyTypeSummary::lookupType(const AstExpr* expr, const Module* module, NotNull<BuiltinTypes> builtinTypes)
+{
+    const TypeId* ty = module->astTypes.find(expr);
+    if (ty)
+        return checkForFamilyInhabitance(follow(*ty), expr->location);
+
+    const TypePackId* tp = module->astTypePacks.find(expr);
+    if (tp)
+    {
+        if (auto fst = first(*tp, /*ignoreHiddenVariadics*/ false))
+            return checkForFamilyInhabitance(*fst, expr->location);
+        else if (finite(*tp) && size(*tp) == 0)
+            return checkForFamilyInhabitance(builtinTypes->nilType, expr->location);
+    }
+
+    return builtinTypes->errorRecoveryType();
+}
+
+TypePackId AnyTypeSummary::reconstructTypePack(AstArray<AstExpr*> exprs, const Module* module, NotNull<BuiltinTypes> builtinTypes)
+{
+    if (exprs.size == 0)
+        return arena.addTypePack(TypePack{{}, std::nullopt});
+
+    std::vector<TypeId> head;
+
+    for (size_t i = 0; i < exprs.size - 1; ++i)
+    {
+        head.push_back(lookupType(exprs.data[i], module, builtinTypes));
+    }
+
+    const TypePackId* tail = module->astTypePacks.find(exprs.data[exprs.size - 1]);
+    if (tail)
+        return arena.addTypePack(TypePack{std::move(head), follow(*tail)});
+    else
+        return arena.addTypePack(TypePack{std::move(head), builtinTypes->errorRecoveryTypePack()});
+}
+
+bool AnyTypeSummary::isAnyCall(const Scope* scope, AstExpr* expr, const Module* module, NotNull<BuiltinTypes> builtinTypes)
+{
+    if (auto call = expr->as<AstExprCall>())
+    {
+        TypePackId args = reconstructTypePack(call->args, module, builtinTypes);
+        if (containsAny(args))
+            return true;
+
+        TypeId func = lookupType(call->func, module, builtinTypes);
+        if (containsAny(func))
+            return true;
+    }
+    return false;
+}
+
+bool AnyTypeSummary::hasVariadicAnys(const Scope* scope, AstExprFunction* expr, const Module* module, NotNull<BuiltinTypes> builtinTypes)
+{
+    if (expr->vararg && expr->varargAnnotation)
+    {
+        auto annot = lookupPackAnnotation(expr->varargAnnotation, module);
+        if (annot && containsAny(*annot))
+        {
+            return true;
+        }
+    }
+    return false;
+}
+
+bool AnyTypeSummary::hasArgAnys(const Scope* scope, AstExprFunction* expr, const Module* module, NotNull<BuiltinTypes> builtinTypes)
+{
+    if (expr->args.size > 0)
+    {
+        for (const AstLocal* arg : expr->args)
+        {
+            if (arg->annotation)
+            {
+                auto annot = lookupAnnotation(arg->annotation, module, builtinTypes);
+                if (containsAny(annot))
+                {
+                    return true;
+                }
+            }
+        }
+    }
+    return false;
+}
+
+bool AnyTypeSummary::hasAnyReturns(const Scope* scope, AstExprFunction* expr, const Module* module, NotNull<BuiltinTypes> builtinTypes)
+{
+    if (!expr->returnAnnotation)
+    {
+        return false;
+    }
+
+    for (AstType* ret : expr->returnAnnotation->types)
+    {
+        if (containsAny(lookupAnnotation(ret, module, builtinTypes)))
+        {
+            return true;
+        }
+    }
+
+    if (expr->returnAnnotation->tailType)
+    {
+        auto annot = lookupPackAnnotation(expr->returnAnnotation->tailType, module);
+        if (annot && containsAny(*annot))
+        {
+            return true;
+        }
+    }
+
+    return false;
+}
+
+bool AnyTypeSummary::isAnyCast(const Scope* scope, AstExpr* expr, const Module* module, NotNull<BuiltinTypes> builtinTypes)
+{
+    if (auto cast = expr->as<AstExprTypeAssertion>())
+    {
+        auto annot = lookupAnnotation(cast->annotation, module, builtinTypes);
+        if (containsAny(annot))
+        {
+            return true;
+        }
+    }
+    return false;
+}
+
+TypeId AnyTypeSummary::lookupAnnotation(AstType* annotation, const Module* module, NotNull<BuiltinTypes> builtintypes)
+{
+    if (FFlag::DebugLuauMagicTypes)
+    {
+        if (auto ref = annotation->as<AstTypeReference>(); ref && ref->parameters.size > 0)
+        {
+            if (auto ann = ref->parameters.data[0].type)
+            {
+                TypeId argTy = lookupAnnotation(ref->parameters.data[0].type, module, builtintypes);
+                return follow(argTy);
+            }
+        }
+    }
+
+    const TypeId* ty = module->astResolvedTypes.find(annotation);
+    if (ty)
+        return checkForTypeFunctionInhabitance(follow(*ty), annotation->location);
+    else
+        return checkForTypeFunctionInhabitance(builtintypes->errorRecoveryType(), annotation->location);
+}
+
+TypeId AnyTypeSummary::checkForTypeFunctionInhabitance(const TypeId instance, const Location location)
+{
+    if (seenTypeFunctionInstances.find(instance))
+        return instance;
+    seenTypeFunctionInstances.insert(instance);
+
+    return instance;
+}
+
+std::optional<TypePackId> AnyTypeSummary::lookupPackAnnotation(AstTypePack* annotation, const Module* module)
+{
+    const TypePackId* tp = module->astResolvedTypePacks.find(annotation);
+    if (tp != nullptr)
+        return {follow(*tp)};
+    return {};
+}
+
+bool AnyTypeSummary::containsAny(TypeId typ)
+{
+    typ = follow(typ);
+
+    if (auto t = seen.find(typ); t && !*t)
+    {
+        return false;
+    }
+
+    seen[typ] = false;
+
+    RecursionCounter counter{&recursionCount};
+    if (recursionCount >= FInt::LuauAnySummaryRecursionLimit)
+    {
+        return false;
+    }
+
+    bool found = false;
+
+    if (auto ty = get<AnyType>(typ))
+    {
+        found = true;
+    }
+    else if (auto ty = get<UnknownType>(typ))
+    {
+        found = true;
+    }
+    else if (auto ty = get<TableType>(typ))
+    {
+        for (auto& [_name, prop] : ty->props)
+        {
+            if (FFlag::LuauSolverV2)
+            {
+                if (auto newT = follow(prop.readTy))
+                {
+                    if (containsAny(*newT))
+                        found = true;
+                }
+                else if (auto newT = follow(prop.writeTy))
+                {
+                    if (containsAny(*newT))
+                        found = true;
+                }
+            }
+            else
+            {
+                if (containsAny(prop.type()))
+                    found = true;
+            }
+        }
+    }
+    else if (auto ty = get<IntersectionType>(typ))
+    {
+        for (auto part : ty->parts)
+        {
+            if (containsAny(part))
+            {
+                found = true;
+            }
+        }
+    }
+    else if (auto ty = get<UnionType>(typ))
+    {
+        for (auto option : ty->options)
+        {
+            if (containsAny(option))
+            {
+                found = true;
+            }
+        }
+    }
+    else if (auto ty = get<FunctionType>(typ))
+    {
+        if (containsAny(ty->argTypes))
+            found = true;
+        else if (containsAny(ty->retTypes))
+            found = true;
+    }
+
+    seen[typ] = found;
+
+    return found;
+}
+
+bool AnyTypeSummary::containsAny(TypePackId typ)
+{
+    typ = follow(typ);
+
+    if (auto t = seen.find(typ); t && !*t)
+    {
+        return false;
+    }
+
+    seen[typ] = false;
+
+    auto [head, tail] = flatten(typ);
+    bool found = false;
+
+    for (auto tp : head)
+    {
+        if (containsAny(tp))
+            found = true;
+    }
+
+    if (tail)
+    {
+        if (auto vtp = get<VariadicTypePack>(tail))
+        {
+            if (auto ty = get<AnyType>(follow(vtp->ty)))
+            {
+                found = true;
+            }
+        }
+        else if (auto tftp = get<TypeFunctionInstanceTypePack>(tail))
+        {
+
+            for (TypePackId tp : tftp->packArguments)
+            {
+                if (containsAny(tp))
+                {
+                    found = true;
+                }
+            }
+
+            for (TypeId t : tftp->typeArguments)
+            {
+                if (containsAny(t))
+                {
+                    found = true;
+                }
+            }
+        }
+    }
+
+    seen[typ] = found;
+
+    return found;
+}
+
+const Scope* AnyTypeSummary::findInnerMostScope(const Location location, const Module* module)
+{
+    const Scope* bestScope = module->getModuleScope().get();
+
+    bool didNarrow = false;
+    do
+    {
+        didNarrow = false;
+        for (auto scope : bestScope->children)
+        {
+            if (scope->location.encloses(location))
+            {
+                bestScope = scope.get();
+                didNarrow = true;
+                break;
+            }
+        }
+    } while (didNarrow && bestScope->children.size() > 0);
+
+    return bestScope;
+}
+
+std::optional<AstExpr*> AnyTypeSummary::matchRequire(const AstExprCall& call)
+{
+    const char* require = "require";
+
+    if (call.args.size != 1)
+        return std::nullopt;
+
+    const AstExprGlobal* funcAsGlobal = call.func->as<AstExprGlobal>();
+    if (!funcAsGlobal || funcAsGlobal->name != require)
+        return std::nullopt;
+
+    if (call.args.size != 1)
+        return std::nullopt;
+
+    return call.args.data[0];
+}
+
+AstNode* AnyTypeSummary::getNode(AstStatBlock* root, AstNode* node)
+{
+    FindReturnAncestry finder(node, root->location.end);
+    root->visit(&finder);
+
+    if (!finder.currNode)
+        finder.currNode = node;
+
+    LUAU_ASSERT(finder.found && finder.currNode);
+    return finder.currNode;
+}
+
+bool AnyTypeSummary::FindReturnAncestry::visit(AstStatLocalFunction* node)
+{
+    currNode = node;
+    return !found;
+}
+
+bool AnyTypeSummary::FindReturnAncestry::visit(AstStatFunction* node)
+{
+    currNode = node;
+    return !found;
+}
+
+bool AnyTypeSummary::FindReturnAncestry::visit(AstType* node)
+{
+    return !found;
+}
+
+bool AnyTypeSummary::FindReturnAncestry::visit(AstNode* node)
+{
+    if (node == stat)
+    {
+        found = true;
+    }
+
+    if (node->location.end == rootEnd && stat->location.end >= rootEnd)
+    {
+        currNode = node;
+        found = true;
+    }
+
+    return !found;
+}
+
+
+AnyTypeSummary::TypeInfo::TypeInfo(Pattern code, std::string node, TelemetryTypePair type)
+    : code(code)
+    , node(node)
+    , type(type)
+{
+}
+
+AnyTypeSummary::FindReturnAncestry::FindReturnAncestry(AstNode* stat, Position rootEnd)
+    : stat(stat)
+    , rootEnd(rootEnd)
+{
+}
+
+AnyTypeSummary::AnyTypeSummary() {}
+
+} // namespace Luau

Analysis/src/AstJsonEncoder.cpp

@@ -1065,11 +1065,6 @@ struct AstJsonEncoder : public AstVisitor
         );
     }
 
-    void write(class AstTypeOptional* node)
-    {
-        writeNode(node, "AstTypeOptional", [&]() {});
-    }
-
     void write(class AstTypeUnion* node)
     {
         writeNode(
@@ -1151,8 +1146,6 @@ struct AstJsonEncoder : public AstVisitor
             return writeString("checked");
         case AstAttr::Type::Native:
             return writeString("native");
-        case AstAttr::Type::Deprecated:
-            return writeString("deprecated");
         }
     }
 

Analysis/src/Autocomplete.cpp

@@ -2,7 +2,6 @@
 #include "Luau/Autocomplete.h"
 
 #include "Luau/AstQuery.h"
-#include "Luau/TimeTrace.h"
 #include "Luau/TypeArena.h"
 #include "Luau/Module.h"
 #include "Luau/Frontend.h"
@@ -16,9 +15,6 @@ namespace Luau
 
 AutocompleteResult autocomplete(Frontend& frontend, const ModuleName& moduleName, Position position, StringCompletionCallback callback)
 {
-    LUAU_TIMETRACE_SCOPE("Luau::autocomplete", "Autocomplete");
-    LUAU_TIMETRACE_ARGUMENT("name", moduleName.c_str());
-
     const SourceModule* sourceModule = frontend.getSourceModule(moduleName);
     if (!sourceModule)
         return {};

Analysis/src/AutocompleteCore.cpp

@@ -10,7 +10,6 @@
 #include "Luau/Common.h"
 #include "Luau/FileResolver.h"
 #include "Luau/Frontend.h"
-#include "Luau/TimeTrace.h"
 #include "Luau/ToString.h"
 #include "Luau/Subtyping.h"
 #include "Luau/TypeInfer.h"
@@ -23,14 +22,9 @@
 LUAU_FASTFLAG(LuauSolverV2)
 LUAU_FASTINT(LuauTypeInferIterationLimit)
 LUAU_FASTINT(LuauTypeInferRecursionLimit)
-LUAU_FASTFLAGVARIABLE(DebugLuauMagicVariableNames)
-
-LUAU_FASTFLAG(LuauExposeRequireByStringAutocomplete)
 
 LUAU_FASTFLAGVARIABLE(LuauAutocompleteRefactorsForIncrementalAutocomplete)
-
-LUAU_FASTFLAGVARIABLE(LuauAutocompleteUsesModuleForTypeCompatibility)
-LUAU_FASTFLAGVARIABLE(LuauAutocompleteUnionCopyPreviousSeen)
+LUAU_FASTFLAGVARIABLE(LuauAutocompleteUseLimits)
 
 static const std::unordered_set<std::string> kStatementStartingKeywords =
     {"while", "if", "local", "repeat", "function", "do", "for", "return", "break", "continue", "type", "export"};
@@ -152,91 +146,44 @@ static std::optional<TypeId> findExpectedTypeAt(const Module& module, AstNode* n
     return *it;
 }
 
-static bool checkTypeMatch(
-    const Module& module,
-    TypeId subTy,
-    TypeId superTy,
-    NotNull<Scope> scope,
-    TypeArena* typeArena,
-    NotNull<BuiltinTypes> builtinTypes
-)
+static bool checkTypeMatch(TypeId subTy, TypeId superTy, NotNull<Scope> scope, TypeArena* typeArena, NotNull<BuiltinTypes> builtinTypes)
 {
     InternalErrorReporter iceReporter;
     UnifierSharedState unifierState(&iceReporter);
     SimplifierPtr simplifier = newSimplifier(NotNull{typeArena}, builtinTypes);
     Normalizer normalizer{typeArena, builtinTypes, NotNull{&unifierState}};
-    if (FFlag::LuauAutocompleteUsesModuleForTypeCompatibility)
+
+    if (FFlag::LuauSolverV2)
     {
-        if (module.checkedInNewSolver)
-        {
-            TypeCheckLimits limits;
-            TypeFunctionRuntime typeFunctionRuntime{
-                NotNull{&iceReporter}, NotNull{&limits}
-            }; // TODO: maybe subtyping checks should not invoke user-defined type function runtime
+        TypeCheckLimits limits;
+        TypeFunctionRuntime typeFunctionRuntime{
+            NotNull{&iceReporter}, NotNull{&limits}
+        }; // TODO: maybe subtyping checks should not invoke user-defined type function runtime
 
-            unifierState.counters.recursionLimit = FInt::LuauTypeInferRecursionLimit;
-            unifierState.counters.iterationLimit = FInt::LuauTypeInferIterationLimit;
+        unifierState.counters.recursionLimit = FInt::LuauTypeInferRecursionLimit;
+        unifierState.counters.iterationLimit = FInt::LuauTypeInferIterationLimit;
 
-            Subtyping subtyping{
-                builtinTypes,
-                NotNull{typeArena},
-                NotNull{simplifier.get()},
-                NotNull{&normalizer},
-                NotNull{&typeFunctionRuntime},
-                NotNull{&iceReporter}
-            };
+        Subtyping subtyping{
+            builtinTypes, NotNull{typeArena}, NotNull{simplifier.get()}, NotNull{&normalizer}, NotNull{&typeFunctionRuntime}, NotNull{&iceReporter}
+        };
 
-            return subtyping.isSubtype(subTy, superTy, scope).isSubtype;
-        }
-        else
-        {
-            Unifier unifier(NotNull<Normalizer>{&normalizer}, scope, Location(), Variance::Covariant);
-
-            // Cost of normalization can be too high for autocomplete response time requirements
-            unifier.normalize = false;
-            unifier.checkInhabited = false;
-
-            unifierState.counters.recursionLimit = FInt::LuauTypeInferRecursionLimit;
-            unifierState.counters.iterationLimit = FInt::LuauTypeInferIterationLimit;
-
-            return unifier.canUnify(subTy, superTy).empty();
-        }
+        return subtyping.isSubtype(subTy, superTy, scope).isSubtype;
     }
     else
     {
-        if (FFlag::LuauSolverV2)
-        {
-            TypeCheckLimits limits;
-            TypeFunctionRuntime typeFunctionRuntime{
-                NotNull{&iceReporter}, NotNull{&limits}
-            }; // TODO: maybe subtyping checks should not invoke user-defined type function runtime
+        Unifier unifier(NotNull<Normalizer>{&normalizer}, scope, Location(), Variance::Covariant);
 
+        // Cost of normalization can be too high for autocomplete response time requirements
+        unifier.normalize = false;
+        unifier.checkInhabited = false;
+
+        if (FFlag::LuauAutocompleteUseLimits)
+        {
             unifierState.counters.recursionLimit = FInt::LuauTypeInferRecursionLimit;
             unifierState.counters.iterationLimit = FInt::LuauTypeInferIterationLimit;
-
-            Subtyping subtyping{
-                builtinTypes,
-                NotNull{typeArena},
-                NotNull{simplifier.get()},
-                NotNull{&normalizer},
-                NotNull{&typeFunctionRuntime},
-                NotNull{&iceReporter}
-            };
-
-            return subtyping.isSubtype(subTy, superTy, scope).isSubtype;
         }
-        else
-        {
-            Unifier unifier(NotNull<Normalizer>{&normalizer}, scope, Location(), Variance::Covariant);
 
-            // Cost of normalization can be too high for autocomplete response time requirements
-            unifier.normalize = false;
-            unifier.checkInhabited = false;
-            unifierState.counters.recursionLimit = FInt::LuauTypeInferRecursionLimit;
-            unifierState.counters.iterationLimit = FInt::LuauTypeInferIterationLimit;
-
-            return unifier.canUnify(subTy, superTy).empty();
-        }
+        return unifier.canUnify(subTy, superTy).empty();
     }
 }
 
@@ -262,10 +209,10 @@ static TypeCorrectKind checkTypeCorrectKind(
 
     TypeId expectedType = follow(*typeAtPosition);
 
-    auto checkFunctionType = [typeArena, builtinTypes, moduleScope, &expectedType, &module](const FunctionType* ftv)
+    auto checkFunctionType = [typeArena, builtinTypes, moduleScope, &expectedType](const FunctionType* ftv)
     {
         if (std::optional<TypeId> firstRetTy = first(ftv->retTypes))
-            return checkTypeMatch(module, *firstRetTy, expectedType, moduleScope, typeArena, builtinTypes);
+            return checkTypeMatch(*firstRetTy, expectedType, moduleScope, typeArena, builtinTypes);
 
         return false;
     };
@@ -288,7 +235,7 @@ static TypeCorrectKind checkTypeCorrectKind(
         }
     }
 
-    return checkTypeMatch(module, ty, expectedType, moduleScope, typeArena, builtinTypes) ? TypeCorrectKind::Correct : TypeCorrectKind::None;
+    return checkTypeMatch(ty, expectedType, moduleScope, typeArena, builtinTypes) ? TypeCorrectKind::Correct : TypeCorrectKind::None;
 }
 
 enum class PropIndexType
@@ -339,7 +286,7 @@ static void autocompleteProps(
             // When called with '.', but declared with 'self', it is considered invalid if first argument is compatible
             if (std::optional<TypeId> firstArgTy = first(ftv->argTypes))
             {
-                if (checkTypeMatch(module, rootTy, *firstArgTy, NotNull{module.getModuleScope().get()}, typeArena, builtinTypes))
+                if (checkTypeMatch(rootTy, *firstArgTy, NotNull{module.getModuleScope().get()}, typeArena, builtinTypes))
                     return calledWithSelf;
             }
 
@@ -485,21 +432,6 @@ static void autocompleteProps(
             AutocompleteEntryMap inner;
             std::unordered_set<TypeId> innerSeen;
 
-            // If we don't do this, and we have the misfortune of receiving a
-            // recursive union like:
-            //
-            //  t1 where t1 = t1 | Class
-            //
-            // Then we are on a one way journey to a stack overflow.
-            if (FFlag::LuauAutocompleteUnionCopyPreviousSeen)
-            {
-                for (auto ty: seen)
-                {
-                    if (is<UnionType, IntersectionType>(ty))
-                        innerSeen.insert(ty);
-                }
-            }
-
             if (isNil(*iter))
             {
                 ++iter;
@@ -1362,15 +1294,6 @@ static AutocompleteContext autocompleteExpression(
 
     AstNode* node = ancestry.rbegin()[0];
 
-    if (FFlag::DebugLuauMagicVariableNames)
-    {
-        InternalErrorReporter ice;
-        if (auto local = node->as<AstExprLocal>(); local && local->local->name == "_luau_autocomplete_ice")
-            ice.ice("_luau_autocomplete_ice encountered", local->location);
-        if (auto global = node->as<AstExprGlobal>(); global && global->name == "_luau_autocomplete_ice")
-            ice.ice("_luau_autocomplete_ice encountered", global->location);
-    }
-
     if (node->is<AstExprIndexName>())
     {
         if (auto it = module.astTypes.find(node->asExpr()))
@@ -1537,14 +1460,10 @@ static std::optional<AutocompleteEntryMap> convertRequireSuggestionsToAutocomple
         return std::nullopt;
 
     AutocompleteEntryMap result;
-    for (RequireSuggestion& suggestion : *suggestions)
+    for (const RequireSuggestion& suggestion : *suggestions)
     {
         AutocompleteEntry entry = {AutocompleteEntryKind::RequirePath};
         entry.insertText = std::move(suggestion.fullPath);
-        if (FFlag::LuauExposeRequireByStringAutocomplete)
-        {
-            entry.tags = std::move(suggestion.tags);
-        }
         result[std::move(suggestion.label)] = std::move(entry);
     }
     return result;
@@ -1795,7 +1714,6 @@ AutocompleteResult autocomplete_(
     StringCompletionCallback callback
 )
 {
-    LUAU_TIMETRACE_SCOPE("Luau::autocomplete_", "AutocompleteCore");
     AstNode* node = ancestry.back();
 
     AstExprConstantNil dummy{Location{}};

Analysis/src/BuiltinDefinitions.cpp

@@ -32,8 +32,8 @@ LUAU_FASTFLAG(LuauSolverV2)
 LUAU_FASTFLAGVARIABLE(LuauStringFormatErrorSuppression)
 LUAU_FASTFLAGVARIABLE(LuauTableCloneClonesType3)
 LUAU_FASTFLAG(LuauTrackInteriorFreeTypesOnScope)
+LUAU_FASTFLAGVARIABLE(LuauFreezeIgnorePersistent)
 LUAU_FASTFLAGVARIABLE(LuauFollowTableFreeze)
-LUAU_FASTFLAGVARIABLE(LuauUserTypeFunTypecheck)
 
 namespace Luau
 {
@@ -288,22 +288,6 @@ void assignPropDocumentationSymbols(TableType::Props& props, const std::string&
     }
 }
 
-static void finalizeGlobalBindings(ScopePtr scope)
-{
-    LUAU_ASSERT(FFlag::LuauUserTypeFunTypecheck);
-
-    for (const auto& pair : scope->bindings)
-    {
-        persist(pair.second.typeId);
-
-        if (TableType* ttv = getMutable<TableType>(pair.second.typeId))
-        {
-            if (!ttv->name)
-                ttv->name = "typeof(" + toString(pair.first) + ")";
-        }
-    }
-}
-
 void registerBuiltinGlobals(Frontend& frontend, GlobalTypes& globals, bool typeCheckForAutocomplete)
 {
     LUAU_ASSERT(!globals.globalTypes.types.isFrozen());
@@ -415,21 +399,14 @@ void registerBuiltinGlobals(Frontend& frontend, GlobalTypes& globals, bool typeC
         // clang-format on
     }
 
-    if (FFlag::LuauUserTypeFunTypecheck)
+    for (const auto& pair : globals.globalScope->bindings)
     {
-        finalizeGlobalBindings(globals.globalScope);
-    }
-    else
-    {
-        for (const auto& pair : globals.globalScope->bindings)
-        {
-            persist(pair.second.typeId);
+        persist(pair.second.typeId);
 
-            if (TableType* ttv = getMutable<TableType>(pair.second.typeId))
-            {
-                if (!ttv->name)
-                    ttv->name = "typeof(" + toString(pair.first) + ")";
-            }
+        if (TableType* ttv = getMutable<TableType>(pair.second.typeId))
+        {
+            if (!ttv->name)
+                ttv->name = "typeof(" + toString(pair.first) + ")";
         }
     }
 
@@ -490,59 +467,6 @@ void registerBuiltinGlobals(Frontend& frontend, GlobalTypes& globals, bool typeC
     TypeId requireTy = getGlobalBinding(globals, "require");
     attachTag(requireTy, kRequireTagName);
     attachMagicFunction(requireTy, std::make_shared<MagicRequire>());
-
-    if (FFlag::LuauUserTypeFunTypecheck)
-    {
-        // Global scope cannot be the parent of the type checking environment because it can be changed by the embedder
-        globals.globalTypeFunctionScope->exportedTypeBindings = globals.globalScope->exportedTypeBindings;
-        globals.globalTypeFunctionScope->builtinTypeNames = globals.globalScope->builtinTypeNames;
-
-        // Type function runtime also removes a few standard libraries and globals, so we will take only the ones that are defined
-        static const char* typeFunctionRuntimeBindings[] = {
-            // Libraries
-            "math",
-            "table",
-            "string",
-            "bit32",
-            "utf8",
-            "buffer",
-
-            // Globals
-            "assert",
-            "error",
-            "print",
-            "next",
-            "ipairs",
-            "pairs",
-            "select",
-            "unpack",
-            "getmetatable",
-            "setmetatable",
-            "rawget",
-            "rawset",
-            "rawlen",
-            "rawequal",
-            "tonumber",
-            "tostring",
-            "type",
-            "typeof",
-        };
-
-        for (auto& name : typeFunctionRuntimeBindings)
-        {
-            AstName astName = globals.globalNames.names->get(name);
-            LUAU_ASSERT(astName.value);
-
-            globals.globalTypeFunctionScope->bindings[astName] = globals.globalScope->bindings[astName];
-        }
-
-        LoadDefinitionFileResult typeFunctionLoadResult = frontend.loadDefinitionFile(
-            globals, globals.globalTypeFunctionScope, getTypeFunctionDefinitionSource(), "@luau", /* captureComments */ false, false
-        );
-        LUAU_ASSERT(typeFunctionLoadResult.success);
-
-        finalizeGlobalBindings(globals.globalTypeFunctionScope);
-    }
 }
 
 static std::vector<TypeId> parseFormatString(NotNull<BuiltinTypes> builtinTypes, const char* data, size_t size)
@@ -1520,7 +1444,7 @@ bool MagicClone::infer(const MagicFunctionCallContext& context)
         return false;
 
     CloneState cloneState{context.solver->builtinTypes};
-    TypeId resultType = shallowClone(inputType, *arena, cloneState, /* ignorePersistent */ true);
+    TypeId resultType = shallowClone(inputType, *arena, cloneState, /* ignorePersistent */ FFlag::LuauFreezeIgnorePersistent);
 
     if (auto tableType = getMutable<TableType>(resultType))
     {
@@ -1557,7 +1481,7 @@ static std::optional<TypeId> freezeTable(TypeId inputType, const MagicFunctionCa
     {
         // Clone the input type, this will become our final result type after we mutate it.
         CloneState cloneState{context.solver->builtinTypes};
-        TypeId resultType = shallowClone(inputType, *arena, cloneState, /* ignorePersistent */ true);
+        TypeId resultType = shallowClone(inputType, *arena, cloneState, /* ignorePersistent */ FFlag::LuauFreezeIgnorePersistent);
         auto tableTy = getMutable<TableType>(resultType);
         // `clone` should not break this.
         LUAU_ASSERT(tableTy);

Analysis/src/Clone.cpp

@@ -1,20 +1,17 @@
 // This file is part of the Luau programming language and is licensed under MIT License; see LICENSE.txt for details
 #include "Luau/Clone.h"
 
-#include "Luau/Common.h"
 #include "Luau/NotNull.h"
 #include "Luau/Type.h"
 #include "Luau/TypePack.h"
 #include "Luau/Unifiable.h"
-#include "Luau/VisitType.h"
 
 LUAU_FASTFLAG(LuauSolverV2)
+LUAU_FASTFLAG(LuauFreezeIgnorePersistent)
 
 // For each `Luau::clone` call, we will clone only up to N amount of types _and_ packs, as controlled by this limit.
 LUAU_FASTINTVARIABLE(LuauTypeCloneIterationLimit, 100'000)
-LUAU_FASTFLAGVARIABLE(LuauClonedTableAndFunctionTypesMustHaveScopes)
-LUAU_FASTFLAGVARIABLE(LuauDoNotClonePersistentBindings)
-LUAU_FASTFLAG(LuauIncrementalAutocompleteDemandBasedCloning)
+
 namespace Luau
 {
 
@@ -31,8 +28,6 @@ const T* get(const Kind& kind)
 
 class TypeCloner
 {
-
-protected:
     NotNull<TypeArena> arena;
     NotNull<BuiltinTypes> builtinTypes;
 
@@ -67,8 +62,6 @@ public:
     {
     }
 
-    virtual ~TypeCloner() = default;
-
     TypeId clone(TypeId ty)
     {
         shallowClone(ty);
@@ -127,13 +120,12 @@ private:
         }
     }
 
-protected:
     std::optional<TypeId> find(TypeId ty) const
     {
         ty = follow(ty, FollowOption::DisableLazyTypeThunks);
         if (auto it = types->find(ty); it != types->end())
             return it->second;
-        else if (ty->persistent && ty != forceTy)
+        else if (ty->persistent && (!FFlag::LuauFreezeIgnorePersistent || ty != forceTy))
             return ty;
         return std::nullopt;
     }
@@ -143,7 +135,7 @@ protected:
         tp = follow(tp);
         if (auto it = packs->find(tp); it != packs->end())
             return it->second;
-        else if (tp->persistent && tp != forceTp)
+        else if (tp->persistent && (!FFlag::LuauFreezeIgnorePersistent || tp != forceTp))
             return tp;
         return std::nullopt;
     }
@@ -162,14 +154,14 @@ protected:
     }
 
 public:
-    virtual TypeId shallowClone(TypeId ty)
+    TypeId shallowClone(TypeId ty)
     {
         // We want to [`Luau::follow`] but without forcing the expansion of [`LazyType`]s.
         ty = follow(ty, FollowOption::DisableLazyTypeThunks);
 
         if (auto clone = find(ty))
             return *clone;
-        else if (ty->persistent && ty != forceTy)
+        else if (ty->persistent && (!FFlag::LuauFreezeIgnorePersistent || ty != forceTy))
             return ty;
 
         TypeId target = arena->addType(ty->ty);
@@ -189,13 +181,13 @@ public:
         return target;
     }
 
-    virtual TypePackId shallowClone(TypePackId tp)
+    TypePackId shallowClone(TypePackId tp)
     {
         tp = follow(tp);
 
         if (auto clone = find(tp))
             return *clone;
-        else if (tp->persistent && tp != forceTp)
+        else if (tp->persistent && (!FFlag::LuauFreezeIgnorePersistent || tp != forceTp))
             return tp;
 
         TypePackId target = arena->addTypePack(tp->ty);
@@ -397,7 +389,7 @@ private:
             ty = shallowClone(ty);
     }
 
-    virtual void cloneChildren(LazyType* t)
+    void cloneChildren(LazyType* t)
     {
         if (auto unwrapped = t->unwrapped.load())
             t->unwrapped.store(shallowClone(unwrapped));
@@ -477,99 +469,11 @@ private:
     }
 };
 
-class FragmentAutocompleteTypeCloner final : public TypeCloner
-{
-    Scope* replacementForNullScope = nullptr;
-
-public:
-    FragmentAutocompleteTypeCloner(
-        NotNull<TypeArena> arena,
-        NotNull<BuiltinTypes> builtinTypes,
-        NotNull<SeenTypes> types,
-        NotNull<SeenTypePacks> packs,
-        TypeId forceTy,
-        TypePackId forceTp,
-        Scope* replacementForNullScope
-    )
-        : TypeCloner(arena, builtinTypes, types, packs, forceTy, forceTp)
-        , replacementForNullScope(replacementForNullScope)
-    {
-        LUAU_ASSERT(replacementForNullScope);
-    }
-
-    TypeId shallowClone(TypeId ty) override
-    {
-        // We want to [`Luau::follow`] but without forcing the expansion of [`LazyType`]s.
-        ty = follow(ty, FollowOption::DisableLazyTypeThunks);
-
-        if (auto clone = find(ty))
-            return *clone;
-        else if (ty->persistent && ty != forceTy)
-            return ty;
-
-        TypeId target = arena->addType(ty->ty);
-        asMutable(target)->documentationSymbol = ty->documentationSymbol;
-
-        if (auto generic = getMutable<GenericType>(target))
-            generic->scope = nullptr;
-        else if (auto free = getMutable<FreeType>(target))
-        {
-            free->scope = replacementForNullScope;
-        }
-        else if (auto tt = getMutable<TableType>(target))
-        {
-            if (FFlag::LuauClonedTableAndFunctionTypesMustHaveScopes)
-                tt->scope = replacementForNullScope;
-        }
-        else if (auto fn = getMutable<FunctionType>(target))
-        {
-            if (FFlag::LuauClonedTableAndFunctionTypesMustHaveScopes)
-                fn->scope = replacementForNullScope;
-        }
-
-        (*types)[ty] = target;
-        queue.emplace_back(target);
-        return target;
-    }
-
-    TypePackId shallowClone(TypePackId tp) override
-    {
-        tp = follow(tp);
-
-        if (auto clone = find(tp))
-            return *clone;
-        else if (tp->persistent && tp != forceTp)
-            return tp;
-
-        TypePackId target = arena->addTypePack(tp->ty);
-
-        if (auto generic = getMutable<GenericTypePack>(target))
-            generic->scope = nullptr;
-        else if (auto free = getMutable<FreeTypePack>(target))
-            free->scope = replacementForNullScope;
-
-        (*packs)[tp] = target;
-        queue.emplace_back(target);
-        return target;
-    }
-
-    void cloneChildren(LazyType* t) override
-    {
-        // Do not clone lazy types
-        if (!FFlag::LuauIncrementalAutocompleteDemandBasedCloning)
-        {
-            if (auto unwrapped = t->unwrapped.load())
-                t->unwrapped.store(shallowClone(unwrapped));
-        }
-    }
-};
-
-
 } // namespace
 
 TypePackId shallowClone(TypePackId tp, TypeArena& dest, CloneState& cloneState, bool ignorePersistent)
 {
-    if (tp->persistent && !ignorePersistent)
+    if (tp->persistent && (!FFlag::LuauFreezeIgnorePersistent || !ignorePersistent))
         return tp;
 
     TypeCloner cloner{
@@ -578,7 +482,7 @@ TypePackId shallowClone(TypePackId tp, TypeArena& dest, CloneState& cloneState,
         NotNull{&cloneState.seenTypes},
         NotNull{&cloneState.seenTypePacks},
         nullptr,
-        ignorePersistent ? tp : nullptr
+        FFlag::LuauFreezeIgnorePersistent && ignorePersistent ? tp : nullptr
     };
 
     return cloner.shallowClone(tp);
@@ -586,7 +490,7 @@ TypePackId shallowClone(TypePackId tp, TypeArena& dest, CloneState& cloneState,
 
 TypeId shallowClone(TypeId typeId, TypeArena& dest, CloneState& cloneState, bool ignorePersistent)
 {
-    if (typeId->persistent && !ignorePersistent)
+    if (typeId->persistent && (!FFlag::LuauFreezeIgnorePersistent || !ignorePersistent))
         return typeId;
 
     TypeCloner cloner{
@@ -594,7 +498,7 @@ TypeId shallowClone(TypeId typeId, TypeArena& dest, CloneState& cloneState, bool
         cloneState.builtinTypes,
         NotNull{&cloneState.seenTypes},
         NotNull{&cloneState.seenTypePacks},
-        ignorePersistent ? typeId : nullptr,
+        FFlag::LuauFreezeIgnorePersistent && ignorePersistent ? typeId : nullptr,
         nullptr
     };
 
@@ -660,96 +564,4 @@ Binding clone(const Binding& binding, TypeArena& dest, CloneState& cloneState)
     return b;
 }
 
-TypePackId cloneIncremental(TypePackId tp, TypeArena& dest, CloneState& cloneState, Scope* freshScopeForFreeTypes)
-{
-    if (tp->persistent)
-        return tp;
-
-    FragmentAutocompleteTypeCloner cloner{
-        NotNull{&dest},
-        cloneState.builtinTypes,
-        NotNull{&cloneState.seenTypes},
-        NotNull{&cloneState.seenTypePacks},
-        nullptr,
-        nullptr,
-        freshScopeForFreeTypes
-    };
-    return cloner.clone(tp);
-}
-
-TypeId cloneIncremental(TypeId typeId, TypeArena& dest, CloneState& cloneState, Scope* freshScopeForFreeTypes)
-{
-    if (typeId->persistent)
-        return typeId;
-
-    FragmentAutocompleteTypeCloner cloner{
-        NotNull{&dest},
-        cloneState.builtinTypes,
-        NotNull{&cloneState.seenTypes},
-        NotNull{&cloneState.seenTypePacks},
-        nullptr,
-        nullptr,
-        freshScopeForFreeTypes
-    };
-    return cloner.clone(typeId);
-}
-
-TypeFun cloneIncremental(const TypeFun& typeFun, TypeArena& dest, CloneState& cloneState, Scope* freshScopeForFreeTypes)
-{
-    FragmentAutocompleteTypeCloner cloner{
-        NotNull{&dest},
-        cloneState.builtinTypes,
-        NotNull{&cloneState.seenTypes},
-        NotNull{&cloneState.seenTypePacks},
-        nullptr,
-        nullptr,
-        freshScopeForFreeTypes
-    };
-
-    TypeFun copy = typeFun;
-
-    for (auto& param : copy.typeParams)
-    {
-        param.ty = cloner.clone(param.ty);
-
-        if (param.defaultValue)
-            param.defaultValue = cloner.clone(*param.defaultValue);
-    }
-
-    for (auto& param : copy.typePackParams)
-    {
-        param.tp = cloner.clone(param.tp);
-
-        if (param.defaultValue)
-            param.defaultValue = cloner.clone(*param.defaultValue);
-    }
-
-    copy.type = cloner.clone(copy.type);
-
-    return copy;
-}
-
-Binding cloneIncremental(const Binding& binding, TypeArena& dest, CloneState& cloneState, Scope* freshScopeForFreeTypes)
-{
-    FragmentAutocompleteTypeCloner cloner{
-        NotNull{&dest},
-        cloneState.builtinTypes,
-        NotNull{&cloneState.seenTypes},
-        NotNull{&cloneState.seenTypePacks},
-        nullptr,
-        nullptr,
-        freshScopeForFreeTypes
-    };
-
-    Binding b;
-    b.deprecated = binding.deprecated;
-    b.deprecatedSuggestion = binding.deprecatedSuggestion;
-    b.documentationSymbol = binding.documentationSymbol;
-    b.location = binding.location;
-    b.typeId = FFlag::LuauDoNotClonePersistentBindings && binding.typeId->persistent ? binding.typeId : cloner.clone(binding.typeId);
-
-    return b;
-}
-
-
 } // namespace Luau

Analysis/src/Constraint.cpp

@@ -3,8 +3,6 @@
 #include "Luau/Constraint.h"
 #include "Luau/VisitType.h"
 
-LUAU_FASTFLAG(DebugLuauGreedyGeneralization)
-
 namespace Luau
 {
 
@@ -113,11 +111,6 @@ DenseHashSet<TypeId> Constraint::getMaybeMutatedFreeTypes() const
     {
         rci.traverse(fchc->argsPack);
     }
-    else if (auto fcc = get<FunctionCallConstraint>(*this); fcc && FFlag::DebugLuauGreedyGeneralization)
-    {
-        rci.traverse(fcc->fn);
-        rci.traverse(fcc->argsPack);
-    }
     else if (auto ptc = get<PrimitiveTypeConstraint>(*this))
     {
         rci.traverse(ptc->freeType);
@@ -125,8 +118,7 @@ DenseHashSet<TypeId> Constraint::getMaybeMutatedFreeTypes() const
     else if (auto hpc = get<HasPropConstraint>(*this))
     {
         rci.traverse(hpc->resultType);
-        if (FFlag::DebugLuauGreedyGeneralization)
-            rci.traverse(hpc->subjectType);
+        // `HasPropConstraints` should not mutate `subjectType`.
     }
     else if (auto hic = get<HasIndexerConstraint>(*this))
     {

Analysis/src/ConstraintGenerator.cpp

@@ -16,7 +16,6 @@
 #include "Luau/Scope.h"
 #include "Luau/Simplify.h"
 #include "Luau/StringUtils.h"
-#include "Luau/Subtyping.h"
 #include "Luau/TableLiteralInference.h"
 #include "Luau/TimeTrace.h"
 #include "Luau/Type.h"
@@ -33,21 +32,14 @@ LUAU_FASTINT(LuauCheckRecursionLimit)
 LUAU_FASTFLAG(DebugLuauLogSolverToJson)
 LUAU_FASTFLAG(DebugLuauMagicTypes)
 LUAU_FASTFLAG(LuauPreserveUnionIntersectionNodeForLeadingTokenSingleType)
-LUAU_FASTFLAGVARIABLE(LuauPropagateExpectedTypesForCalls)
-LUAU_FASTFLAG(DebugLuauGreedyGeneralization)
 
+LUAU_FASTFLAGVARIABLE(LuauNewSolverPrePopulateClasses)
+LUAU_FASTFLAGVARIABLE(LuauNewSolverPopulateTableLocations)
 LUAU_FASTFLAGVARIABLE(LuauTrackInteriorFreeTypesOnScope)
 LUAU_FASTFLAGVARIABLE(LuauDeferBidirectionalInferenceForTableAssignment)
-LUAU_FASTFLAGVARIABLE(LuauUngeneralizedTypesForRecursiveFunctions)
-LUAU_FASTFLAGVARIABLE(LuauGlobalSelfAssignmentCycle)
 
 LUAU_FASTFLAG(LuauFreeTypesMustHaveBounds)
 LUAU_FASTFLAGVARIABLE(LuauInferLocalTypesInMultipleAssignments)
-LUAU_FASTFLAGVARIABLE(LuauDoNotLeakNilInRefinement)
-LUAU_FASTFLAGVARIABLE(LuauExtraFollows)
-LUAU_FASTFLAG(LuauUserTypeFunTypecheck)
-
-LUAU_FASTFLAG(LuauDeprecatedAttribute)
 
 namespace Luau
 {
@@ -188,7 +180,6 @@ ConstraintGenerator::ConstraintGenerator(
     NotNull<BuiltinTypes> builtinTypes,
     NotNull<InternalErrorReporter> ice,
     const ScopePtr& globalScope,
-    const ScopePtr& typeFunctionScope,
     std::function<void(const ModuleName&, const ScopePtr&)> prepareModuleScope,
     DcrLogger* logger,
     NotNull<DataFlowGraph> dfg,
@@ -205,7 +196,6 @@ ConstraintGenerator::ConstraintGenerator(
     , moduleResolver(moduleResolver)
     , ice(ice)
     , globalScope(globalScope)
-    , typeFunctionScope(typeFunctionScope)
     , prepareModuleScope(std::move(prepareModuleScope))
     , requireCycles(std::move(requireCycles))
     , logger(logger)
@@ -227,14 +217,6 @@ void ConstraintGenerator::visitModuleRoot(AstStatBlock* block)
 
     rootScope->returnType = freshTypePack(scope);
 
-    if (FFlag::LuauUserTypeFunTypecheck)
-    {
-        // Create module-local scope for the type function environment
-        ScopePtr localTypeFunctionScope = std::make_shared<Scope>(typeFunctionScope);
-        localTypeFunctionScope->location = block->location;
-        typeFunctionRuntime->rootScope = localTypeFunctionScope;
-    }
-
     TypeId moduleFnTy = arena->addType(FunctionType{TypeLevel{}, rootScope, builtinTypes->anyTypePack, rootScope->returnType});
     interiorTypes.emplace_back();
 
@@ -545,15 +527,7 @@ void ConstraintGenerator::computeRefinement(
 
         // When the top-level expression is `t[x]`, we want to refine it into `nil`, not `never`.
         LUAU_ASSERT(refis->get(proposition->key->def));
-        if (FFlag::LuauDoNotLeakNilInRefinement)
-        {
-            refis->get(proposition->key->def)->shouldAppendNilType =
-                (sense || !eq) && containsSubscriptedDefinition(proposition->key->def) && !proposition->implicitFromCall;
-        }
-        else
-        {
-            refis->get(proposition->key->def)->shouldAppendNilType = (sense || !eq) && containsSubscriptedDefinition(proposition->key->def);
-        }
+        refis->get(proposition->key->def)->shouldAppendNilType = (sense || !eq) && containsSubscriptedDefinition(proposition->key->def);
     }
 }
 
@@ -713,9 +687,6 @@ void ConstraintGenerator::checkAliases(const ScopePtr& scope, AstStatBlock* bloc
     std::unordered_map<Name, Location> aliasDefinitionLocations;
     std::unordered_map<Name, Location> classDefinitionLocations;
 
-    bool hasTypeFunction = false;
-    ScopePtr typeFunctionEnvScope;
-
     // In order to enable mutually-recursive type aliases, we need to
     // populate the type bindings before we actually check any of the
     // alias statements.
@@ -761,9 +732,6 @@ void ConstraintGenerator::checkAliases(const ScopePtr& scope, AstStatBlock* bloc
         }
         else if (auto function = stat->as<AstStatTypeFunction>())
         {
-            if (FFlag::LuauUserTypeFunTypecheck)
-                hasTypeFunction = true;
-
             // If a type function w/ same name has already been defined, error for having duplicates
             if (scope->exportedTypeBindings.count(function->name.value) || scope->privateTypeBindings.count(function->name.value))
             {
@@ -773,8 +741,7 @@ void ConstraintGenerator::checkAliases(const ScopePtr& scope, AstStatBlock* bloc
                 continue;
             }
 
-            // Variable becomes unused with the removal of FFlag::LuauUserTypeFunTypecheck
-            ScopePtr defnScope = FFlag::LuauUserTypeFunTypecheck ? nullptr : childScope(function, scope);
+            ScopePtr defnScope = childScope(function, scope);
 
             // Create TypeFunctionInstanceType
 
@@ -818,6 +785,9 @@ void ConstraintGenerator::checkAliases(const ScopePtr& scope, AstStatBlock* bloc
         }
         else if (auto classDeclaration = stat->as<AstStatDeclareClass>())
         {
+            if (!FFlag::LuauNewSolverPrePopulateClasses)
+                continue;
+
             if (scope->exportedTypeBindings.count(classDeclaration->name.value))
             {
                 auto it = classDefinitionLocations.find(classDeclaration->name.value);
@@ -841,22 +811,11 @@ void ConstraintGenerator::checkAliases(const ScopePtr& scope, AstStatBlock* bloc
         }
     }
 
-    if (FFlag::LuauUserTypeFunTypecheck && hasTypeFunction)
-        typeFunctionEnvScope = std::make_shared<Scope>(typeFunctionRuntime->rootScope);
-
     // Additional pass for user-defined type functions to fill in their environments completely
     for (AstStat* stat : block->body)
     {
         if (auto function = stat->as<AstStatTypeFunction>())
         {
-            if (FFlag::LuauUserTypeFunTypecheck)
-            {
-                // Similar to global pre-population, create a binding for each type function in the scope upfront
-                TypeId bt = arena->addType(BlockedType{});
-                typeFunctionEnvScope->bindings[function->name] = Binding{bt, function->location};
-                astTypeFunctionEnvironmentScopes[function] = typeFunctionEnvScope;
-            }
-
             // Find the type function we have already created
             TypeFunctionInstanceType* mainTypeFun = nullptr;
 
@@ -875,60 +834,51 @@ void ConstraintGenerator::checkAliases(const ScopePtr& scope, AstStatBlock* bloc
                 UserDefinedFunctionData& userFuncData = mainTypeFun->userFuncData;
                 size_t level = 0;
 
-                if (FFlag::LuauUserTypeFunTypecheck)
+                for (Scope* curr = scope.get(); curr; curr = curr->parent.get())
                 {
-                    auto addToEnvironment = [this](UserDefinedFunctionData& userFuncData, ScopePtr scope, const Name& name, TypeId type, size_t level)
+                    for (auto& [name, tf] : curr->privateTypeBindings)
                     {
                         if (userFuncData.environment.find(name))
-                            return;
+                            continue;
 
-                        if (auto ty = get<TypeFunctionInstanceType>(type); ty && ty->userFuncData.definition)
-                        {
+                        if (auto ty = get<TypeFunctionInstanceType>(tf.type); ty && ty->userFuncData.definition)
                             userFuncData.environment[name] = std::make_pair(ty->userFuncData.definition, level);
-
-                            if (auto it = astTypeFunctionEnvironmentScopes.find(ty->userFuncData.definition))
-                            {
-                                if (auto existing = (*it)->linearSearchForBinding(name, /* traverseScopeChain */ false))
-                                    scope->bindings[ty->userFuncData.definition->name] =
-                                        Binding{existing->typeId, ty->userFuncData.definition->location};
-                            }
-                        }
-                    };
-
-                    for (Scope* curr = scope.get(); curr; curr = curr->parent.get())
-                    {
-                        for (auto& [name, tf] : curr->privateTypeBindings)
-                            addToEnvironment(userFuncData, typeFunctionEnvScope, name, tf.type, level);
-
-                        for (auto& [name, tf] : curr->exportedTypeBindings)
-                            addToEnvironment(userFuncData, typeFunctionEnvScope, name, tf.type, level);
-
-                        level++;
                     }
-                }
-                else
-                {
-                    for (Scope* curr = scope.get(); curr; curr = curr->parent.get())
+
+                    for (auto& [name, tf] : curr->exportedTypeBindings)
                     {
-                        for (auto& [name, tf] : curr->privateTypeBindings)
-                        {
-                            if (userFuncData.environment.find(name))
-                                continue;
+                        if (userFuncData.environment.find(name))
+                            continue;
 
-                            if (auto ty = get<TypeFunctionInstanceType>(tf.type); ty && ty->userFuncData.definition)
-                                userFuncData.environment[name] = std::make_pair(ty->userFuncData.definition, level);
-                        }
+                        if (auto ty = get<TypeFunctionInstanceType>(tf.type); ty && ty->userFuncData.definition)
+                            userFuncData.environment[name] = std::make_pair(ty->userFuncData.definition, level);
+                    }
 
-                        for (auto& [name, tf] : curr->exportedTypeBindings)
-                        {
-                            if (userFuncData.environment.find(name))
-                                continue;
+                    level++;
+                }
+            }
+            else if (mainTypeFun)
+            {
+                UserDefinedFunctionData& userFuncData = mainTypeFun->userFuncData;
 
-                            if (auto ty = get<TypeFunctionInstanceType>(tf.type); ty && ty->userFuncData.definition)
-                                userFuncData.environment[name] = std::make_pair(ty->userFuncData.definition, level);
-                        }
+                for (Scope* curr = scope.get(); curr; curr = curr->parent.get())
+                {
+                    for (auto& [name, tf] : curr->privateTypeBindings)
+                    {
+                        if (userFuncData.environment_DEPRECATED.find(name))
+                            continue;
 
-                        level++;
+                        if (auto ty = get<TypeFunctionInstanceType>(tf.type); ty && ty->userFuncData.definition)
+                            userFuncData.environment_DEPRECATED[name] = ty->userFuncData.definition;
+                    }
+
+                    for (auto& [name, tf] : curr->exportedTypeBindings)
+                    {
+                        if (userFuncData.environment_DEPRECATED.find(name))
+                            continue;
+
+                        if (auto ty = get<TypeFunctionInstanceType>(tf.type); ty && ty->userFuncData.definition)
+                            userFuncData.environment_DEPRECATED[name] = ty->userFuncData.definition;
                     }
                 }
             }
@@ -1360,23 +1310,6 @@ ControlFlow ConstraintGenerator::visit(const ScopePtr& scope, AstStatRepeat* rep
     return ControlFlow::None;
 }
 
-static void propagateDeprecatedAttributeToConstraint(ConstraintV& c, const AstExprFunction* func)
-{
-    LUAU_ASSERT(FFlag::LuauDeprecatedAttribute);
-    if (GeneralizationConstraint* genConstraint = c.get_if<GeneralizationConstraint>())
-    {
-        genConstraint->hasDeprecatedAttribute = func->hasAttribute(AstAttr::Type::Deprecated);
-    }
-}
-
-static void propagateDeprecatedAttributeToType(TypeId signature, const AstExprFunction* func)
-{
-    LUAU_ASSERT(FFlag::LuauDeprecatedAttribute);
-    FunctionType* fty = getMutable<FunctionType>(signature);
-    LUAU_ASSERT(fty);
-    fty->isDeprecatedFunction = func->hasAttribute(AstAttr::Type::Deprecated);
-}
-
 ControlFlow ConstraintGenerator::visit(const ScopePtr& scope, AstStatLocalFunction* function)
 {
     // Local
@@ -1414,9 +1347,6 @@ ControlFlow ConstraintGenerator::visit(const ScopePtr& scope, AstStatLocalFuncti
         std::unique_ptr<Constraint> c =
             std::make_unique<Constraint>(constraintScope, function->name->location, GeneralizationConstraint{functionType, sig.signature});
 
-        if (FFlag::LuauDeprecatedAttribute)
-            propagateDeprecatedAttributeToConstraint(c->c, function->func);
-
         Constraint* previous = nullptr;
         forEachConstraint(
             start,
@@ -1440,11 +1370,7 @@ ControlFlow ConstraintGenerator::visit(const ScopePtr& scope, AstStatLocalFuncti
         module->astTypes[function->func] = functionType;
     }
     else
-    {
         module->astTypes[function->func] = sig.signature;
-        if (FFlag::LuauDeprecatedAttribute)
-            propagateDeprecatedAttributeToType(sig.signature, function->func);
-    }
 
     return ControlFlow::None;
 }
@@ -1458,38 +1384,12 @@ ControlFlow ConstraintGenerator::visit(const ScopePtr& scope, AstStatFunction* f
     FunctionSignature sig = checkFunctionSignature(scope, function->func, /* expectedType */ std::nullopt, function->name->location);
     bool sigFullyDefined = !hasFreeType(sig.signature);
 
-    DefId def = dfg->getDef(function->name);
-
-    if (FFlag::LuauUngeneralizedTypesForRecursiveFunctions)
-    {
-        if (AstExprLocal* localName = function->name->as<AstExprLocal>())
-        {
-            sig.bodyScope->bindings[localName->local] = Binding{sig.signature, localName->location};
-            sig.bodyScope->lvalueTypes[def] = sig.signature;
-            sig.bodyScope->rvalueRefinements[def] = sig.signature;
-        }
-        else if (AstExprGlobal* globalName = function->name->as<AstExprGlobal>())
-        {
-            sig.bodyScope->bindings[globalName->name] = Binding{sig.signature, globalName->location};
-            sig.bodyScope->lvalueTypes[def] = sig.signature;
-            sig.bodyScope->rvalueRefinements[def] = sig.signature;
-        }
-        else if (AstExprIndexName* indexName = function->name->as<AstExprIndexName>())
-        {
-            sig.bodyScope->rvalueRefinements[def] = sig.signature;
-        }
-    }
-
     checkFunctionBody(sig.bodyScope, function->func);
     Checkpoint end = checkpoint(this);
 
     TypeId generalizedType = arena->addType(BlockedType{});
     if (sigFullyDefined)
-    {
         emplaceType<BoundType>(asMutable(generalizedType), sig.signature);
-        if (FFlag::LuauDeprecatedAttribute)
-            propagateDeprecatedAttributeToType(sig.signature, function->func);
-    }
     else
     {
         const ScopePtr& constraintScope = sig.signatureScope ? sig.signatureScope : sig.bodyScope;
@@ -1497,9 +1397,6 @@ ControlFlow ConstraintGenerator::visit(const ScopePtr& scope, AstStatFunction* f
         NotNull<Constraint> c = addConstraint(constraintScope, function->name->location, GeneralizationConstraint{generalizedType, sig.signature});
         getMutable<BlockedType>(generalizedType)->setOwner(c);
 
-        if (FFlag::LuauDeprecatedAttribute)
-            propagateDeprecatedAttributeToConstraint(c->c, function->func);
-
         Constraint* previous = nullptr;
         forEachConstraint(
             start,
@@ -1520,6 +1417,7 @@ ControlFlow ConstraintGenerator::visit(const ScopePtr& scope, AstStatFunction* f
         );
     }
 
+    DefId def = dfg->getDef(function->name);
     std::optional<TypeId> existingFunctionTy = follow(lookup(scope, function->name->location, def));
 
     if (AstExprLocal* localName = function->name->as<AstExprLocal>())
@@ -1761,64 +1659,6 @@ ControlFlow ConstraintGenerator::visit(const ScopePtr& scope, AstStatTypeAlias*
 
 ControlFlow ConstraintGenerator::visit(const ScopePtr& scope, AstStatTypeFunction* function)
 {
-    if (!FFlag::LuauUserTypeFunTypecheck)
-        return ControlFlow::None;
-
-    auto scopePtr = astTypeFunctionEnvironmentScopes.find(function);
-    LUAU_ASSERT(scopePtr);
-
-    Checkpoint startCheckpoint = checkpoint(this);
-    FunctionSignature sig = checkFunctionSignature(*scopePtr, function->body, /* expectedType */ std::nullopt);
-
-    // Place this function as a child of the non-type function scope
-    scope->children.push_back(NotNull{sig.signatureScope.get()});
-
-    interiorTypes.push_back(std::vector<TypeId>{});
-    checkFunctionBody(sig.bodyScope, function->body);
-    Checkpoint endCheckpoint = checkpoint(this);
-
-    TypeId generalizedTy = arena->addType(BlockedType{});
-    NotNull<Constraint> gc = addConstraint(
-        sig.signatureScope,
-        function->location,
-        GeneralizationConstraint{
-            generalizedTy, sig.signature, FFlag::LuauTrackInteriorFreeTypesOnScope ? std::vector<TypeId>{} : std::move(interiorTypes.back())
-        }
-    );
-
-    if (FFlag::LuauTrackInteriorFreeTypesOnScope)
-        sig.signatureScope->interiorFreeTypes = std::move(interiorTypes.back());
-
-    getMutable<BlockedType>(generalizedTy)->setOwner(gc);
-    interiorTypes.pop_back();
-
-    Constraint* previous = nullptr;
-    forEachConstraint(
-        startCheckpoint,
-        endCheckpoint,
-        this,
-        [gc, &previous](const ConstraintPtr& constraint)
-        {
-            gc->dependencies.emplace_back(constraint.get());
-
-            if (auto psc = get<PackSubtypeConstraint>(*constraint); psc && psc->returns)
-            {
-                if (previous)
-                    constraint->dependencies.push_back(NotNull{previous});
-
-                previous = constraint.get();
-            }
-        }
-    );
-
-    std::optional<TypeId> existingFunctionTy = (*scopePtr)->lookup(function->name);
-
-    if (!existingFunctionTy)
-        ice->ice("checkAliases did not populate type function name", function->nameLocation);
-
-    if (auto bt = get<BlockedType>(*existingFunctionTy); bt && nullptr == bt->getOwner())
-        emplaceType<BoundType>(asMutable(*existingFunctionTy), generalizedTy);
-
     return ControlFlow::None;
 }
 
@@ -1851,7 +1691,7 @@ ControlFlow ConstraintGenerator::visit(const ScopePtr& scope, AstStatDeclareClas
 {
     // If a class with the same name was already defined, we skip over
     auto bindingIt = scope->exportedTypeBindings.find(declaredClass->name.value);
-    if (bindingIt == scope->exportedTypeBindings.end())
+    if (FFlag::LuauNewSolverPrePopulateClasses && bindingIt == scope->exportedTypeBindings.end())
         return ControlFlow::None;
 
     std::optional<TypeId> superTy = std::make_optional(builtinTypes->classType);
@@ -1868,7 +1708,10 @@ ControlFlow ConstraintGenerator::visit(const ScopePtr& scope, AstStatDeclareClas
 
         // We don't have generic classes, so this assertion _should_ never be hit.
         LUAU_ASSERT(lookupType->typeParams.size() == 0 && lookupType->typePackParams.size() == 0);
-        superTy = follow(lookupType->type);
+        if (FFlag::LuauNewSolverPrePopulateClasses)
+            superTy = follow(lookupType->type);
+        else
+            superTy = lookupType->type;
 
         if (!get<ClassType>(follow(*superTy)))
         {
@@ -1891,8 +1734,14 @@ ControlFlow ConstraintGenerator::visit(const ScopePtr& scope, AstStatDeclareClas
 
     ctv->metatable = metaTy;
 
-    TypeId classBindTy = bindingIt->second.type;
-    emplaceType<BoundType>(asMutable(classBindTy), classTy);
+
+    if (FFlag::LuauNewSolverPrePopulateClasses)
+    {
+        TypeId classBindTy = bindingIt->second.type;
+        emplaceType<BoundType>(asMutable(classBindTy), classTy);
+    }
+    else
+        scope->exportedTypeBindings[className] = TypeFun{{}, classTy};
 
     if (declaredClass->indexer)
     {
@@ -2015,8 +1864,6 @@ ControlFlow ConstraintGenerator::visit(const ScopePtr& scope, AstStatDeclareFunc
     TypeId fnType = arena->addType(FunctionType{TypeLevel{}, funScope.get(), std::move(genericTys), std::move(genericTps), paramPack, retPack, defn});
     FunctionType* ftv = getMutable<FunctionType>(fnType);
     ftv->isCheckedFunction = global->isCheckedFunction();
-    if (FFlag::LuauDeprecatedAttribute)
-        ftv->isDeprecatedFunction = global->hasAttribute(AstAttr::Type::Deprecated);
 
     ftv->argNames.reserve(global->paramNames.size);
     for (const auto& el : global->paramNames)
@@ -2129,7 +1976,7 @@ InferencePack ConstraintGenerator::checkPack(const ScopePtr& scope, AstExprCall*
         if (auto key = dfg->getRefinementKey(indexExpr->expr))
         {
             TypeId discriminantTy = arena->addType(BlockedType{});
-            returnRefinements.push_back(refinementArena.implicitProposition(key, discriminantTy));
+            returnRefinements.push_back(refinementArena.proposition(key, discriminantTy));
             discriminantTypes.push_back(discriminantTy);
         }
         else
@@ -2143,7 +1990,7 @@ InferencePack ConstraintGenerator::checkPack(const ScopePtr& scope, AstExprCall*
         if (auto key = dfg->getRefinementKey(arg))
         {
             TypeId discriminantTy = arena->addType(BlockedType{});
-            returnRefinements.push_back(refinementArena.implicitProposition(key, discriminantTy));
+            returnRefinements.push_back(refinementArena.proposition(key, discriminantTy));
             discriminantTypes.push_back(discriminantTy);
         }
         else
@@ -2184,23 +2031,13 @@ InferencePack ConstraintGenerator::checkPack(const ScopePtr& scope, AstExprCall*
         }
         else if (i < exprArgs.size() - 1 || !(arg->is<AstExprCall>() || arg->is<AstExprVarargs>()))
         {
-            std::optional<TypeId> expectedType = std::nullopt;
-            if (FFlag::LuauPropagateExpectedTypesForCalls && i < expectedTypesForCall.size())
-            {
-                expectedType = expectedTypesForCall[i];
-            }
-            auto [ty, refinement] = check(scope, arg, expectedType, /*forceSingleton*/ false, /*generalize*/ false);
+            auto [ty, refinement] = check(scope, arg, /*expectedType*/ std::nullopt, /*forceSingleton*/ false, /*generalize*/ false);
             args.push_back(ty);
             argumentRefinements.push_back(refinement);
         }
         else
         {
-            std::vector<std::optional<Luau::TypeId>> expectedTypes = {};
-            if (FFlag::LuauPropagateExpectedTypesForCalls && i < expectedTypesForCall.size())
-            {
-                expectedTypes.insert(expectedTypes.end(), expectedTypesForCall.begin() + int(i), expectedTypesForCall.end());
-            }
-            auto [tp, refis] = checkPack(scope, arg, expectedTypes);
+            auto [tp, refis] = checkPack(scope, arg, {});
             argTail = tp;
             argumentRefinements.insert(argumentRefinements.end(), refis.begin(), refis.end());
         }
@@ -2226,7 +2063,7 @@ InferencePack ConstraintGenerator::checkPack(const ScopePtr& scope, AstExprCall*
         {
             std::vector<TypeId> unpackedTypes;
             if (args.size() > 0)
-                target = FFlag::LuauExtraFollows ? follow(args[0]) : args[0];
+                target = args[0];
             else
             {
                 target = arena->addType(BlockedType{});
@@ -2460,7 +2297,8 @@ Inference ConstraintGenerator::check(const ScopePtr& scope, AstExprConstantBool*
 Inference ConstraintGenerator::check(const ScopePtr& scope, AstExprLocal* local)
 {
     const RefinementKey* key = dfg->getRefinementKey(local);
-    LUAU_ASSERT(key);
+    std::optional<DefId> rvalueDef = dfg->getRValueDefForCompoundAssign(local);
+    LUAU_ASSERT(key || rvalueDef);
 
     std::optional<TypeId> maybeTy;
 
@@ -2468,6 +2306,11 @@ Inference ConstraintGenerator::check(const ScopePtr& scope, AstExprLocal* local)
     if (key)
         maybeTy = lookup(scope, local->location, key->def);
 
+    // if the current def doesn't have a type, we might be doing a compound assignment
+    // and therefore might need to look at the rvalue def instead.
+    if (!maybeTy && rvalueDef)
+        maybeTy = lookup(scope, local->location, *rvalueDef);
+
     if (maybeTy)
     {
         TypeId ty = follow(*maybeTy);
@@ -2483,9 +2326,11 @@ Inference ConstraintGenerator::check(const ScopePtr& scope, AstExprLocal* local)
 Inference ConstraintGenerator::check(const ScopePtr& scope, AstExprGlobal* global)
 {
     const RefinementKey* key = dfg->getRefinementKey(global);
-    LUAU_ASSERT(key);
+    std::optional<DefId> rvalueDef = dfg->getRValueDefForCompoundAssign(global);
+    LUAU_ASSERT(key || rvalueDef);
 
-    DefId def = key->def;
+    // we'll use whichever of the two definitions we have here.
+    DefId def = key ? key->def : *rvalueDef;
 
     /* prepopulateGlobalScope() has already added all global functions to the environment by this point, so any
      * global that is not already in-scope is definitely an unknown symbol.
@@ -3027,13 +2872,6 @@ void ConstraintGenerator::visitLValue(const ScopePtr& scope, AstExprGlobal* glob
         DefId def = dfg->getDef(global);
         rootScope->lvalueTypes[def] = rhsType;
 
-        if (FFlag::LuauGlobalSelfAssignmentCycle)
-        {
-            // Ignore possible self-assignment, it doesn't create a new constraint
-            if (annotatedTy == follow(rhsType))
-                return;
-        }
-
         // Sketchy: We're specifically looking for BlockedTypes that were
         // initially created by ConstraintGenerator::prepopulateGlobalScope.
         if (auto bt = get<BlockedType>(follow(*annotatedTy)); bt && !bt->getOwner())
@@ -3092,7 +2930,10 @@ Inference ConstraintGenerator::check(const ScopePtr& scope, AstExprTable* expr,
 
     ttv->state = TableState::Unsealed;
     ttv->definitionModuleName = module->name;
-    ttv->definitionLocation = expr->location;
+    if (FFlag::LuauNewSolverPopulateTableLocations)
+    {
+        ttv->definitionLocation = expr->location;
+    }
     ttv->scope = scope.get();
 
     interiorTypes.back().push_back(ty);
@@ -3175,7 +3016,6 @@ Inference ConstraintGenerator::check(const ScopePtr& scope, AstExprTable* expr,
         else
         {
             Unifier2 unifier{arena, builtinTypes, NotNull{scope.get()}, ice};
-            Subtyping sp{builtinTypes, arena, simplifier, normalizer, typeFunctionRuntime, ice};
             std::vector<TypeId> toBlock;
             // This logic is incomplete as we want to re-run this
             // _after_ blocked types have resolved, but this
@@ -3189,7 +3029,6 @@ Inference ConstraintGenerator::check(const ScopePtr& scope, AstExprTable* expr,
                     builtinTypes,
                     arena,
                     NotNull{&unifier},
-                    NotNull{&sp},
                     *expectedType,
                     ty,
                     expr,
@@ -3228,7 +3067,7 @@ ConstraintGenerator::FunctionSignature ConstraintGenerator::checkFunctionSignatu
     signatureScope = childScope(fn, parent);
 
     // We need to assign returnType before creating bodyScope so that the
-    // return type gets propagated to bodyScope.
+    // return type gets propogated to bodyScope.
     returnType = freshTypePack(signatureScope);
     signatureScope->returnType = returnType;
 
@@ -3391,9 +3230,6 @@ ConstraintGenerator::FunctionSignature ConstraintGenerator::checkFunctionSignatu
     if (expectedType && get<FreeType>(*expectedType))
         bindFreeType(*expectedType, actualFunctionType);
 
-    if (FFlag::DebugLuauGreedyGeneralization)
-        scopeToFunction[signatureScope.get()] = actualFunctionType;
-
     return {
         /* signature */ actualFunctionType,
         /* signatureScope */ signatureScope,
@@ -3556,8 +3392,11 @@ TypeId ConstraintGenerator::resolveTableType(const ScopePtr& scope, AstType* ty,
     TypeId tableTy = arena->addType(TableType{props, indexer, scope->level, scope.get(), TableState::Sealed});
     TableType* ttv = getMutable<TableType>(tableTy);
 
-    ttv->definitionModuleName = module->name;
-    ttv->definitionLocation = tab->location;
+    if (FFlag::LuauNewSolverPopulateTableLocations)
+    {
+        ttv->definitionModuleName = module->name;
+        ttv->definitionLocation = tab->location;
+    }
 
     return tableTy;
 }
@@ -3610,8 +3449,6 @@ TypeId ConstraintGenerator::resolveFunctionType(
     // how to quantify/instantiate it.
     FunctionType ftv{TypeLevel{}, scope.get(), {}, {}, argTypes, returnTypes};
     ftv.isCheckedFunction = fn->isCheckedFunction();
-    if (FFlag::LuauDeprecatedAttribute)
-        ftv.isDeprecatedFunction = fn->hasAttribute(AstAttr::Type::Deprecated);
 
     // This replicates the behavior of the appropriate FunctionType
     // constructors.
@@ -3656,10 +3493,6 @@ TypeId ConstraintGenerator::resolveType(const ScopePtr& scope, AstType* ty, bool
         TypeId exprType = check(scope, tof->expr).ty;
         result = exprType;
     }
-    else if (ty->is<AstTypeOptional>())
-    {
-        return builtinTypes->nilType;
-    }
     else if (auto unionAnnotation = ty->as<AstTypeUnion>())
     {
         if (FFlag::LuauPreserveUnionIntersectionNodeForLeadingTokenSingleType)
@@ -4022,18 +3855,9 @@ struct GlobalPrepopulator : AstVisitor
 void ConstraintGenerator::prepopulateGlobalScopeForFragmentTypecheck(const ScopePtr& globalScope, const ScopePtr& resumeScope, AstStatBlock* program)
 {
     FragmentTypeCheckGlobalPrepopulator gp{NotNull{globalScope.get()}, NotNull{resumeScope.get()}, dfg, arena};
-
     if (prepareModuleScope)
         prepareModuleScope(module->name, resumeScope);
-
     program->visit(&gp);
-
-    if (FFlag::LuauUserTypeFunTypecheck)
-    {
-        // Handle type function globals as well, without preparing a module scope since they have a separate environment
-        GlobalPrepopulator tfgp{NotNull{typeFunctionRuntime->rootScope.get()}, arena, dfg};
-        program->visit(&tfgp);
-    }
 }
 
 void ConstraintGenerator::prepopulateGlobalScope(const ScopePtr& globalScope, AstStatBlock* program)
@@ -4044,13 +3868,6 @@ void ConstraintGenerator::prepopulateGlobalScope(const ScopePtr& globalScope, As
         prepareModuleScope(module->name, globalScope);
 
     program->visit(&gp);
-
-    if (FFlag::LuauUserTypeFunTypecheck)
-    {
-        // Handle type function globals as well, without preparing a module scope since they have a separate environment
-        GlobalPrepopulator tfgp{NotNull{typeFunctionRuntime->rootScope.get()}, arena, dfg};
-        program->visit(&tfgp);
-    }
 }
 
 bool ConstraintGenerator::recordPropertyAssignment(TypeId ty)

Analysis/src/ConstraintSolver.cpp

@@ -27,20 +27,17 @@
 #include <algorithm>
 #include <utility>
 
-LUAU_FASTFLAGVARIABLE(DebugLuauAssertOnForcedConstraint)
 LUAU_FASTFLAGVARIABLE(DebugLuauLogSolver)
 LUAU_FASTFLAGVARIABLE(DebugLuauLogSolverIncludeDependencies)
 LUAU_FASTFLAGVARIABLE(DebugLuauLogBindings)
 LUAU_FASTINTVARIABLE(LuauSolverRecursionLimit, 500)
 LUAU_FASTFLAGVARIABLE(DebugLuauEqSatSimplification)
+LUAU_FASTFLAG(LuauNewSolverPopulateTableLocations)
+LUAU_FASTFLAGVARIABLE(LuauAllowNilAssignmentToIndexer)
 LUAU_FASTFLAG(LuauTrackInteriorFreeTypesOnScope)
+LUAU_FASTFLAGVARIABLE(LuauAlwaysFillInFunctionCallDiscriminantTypes)
 LUAU_FASTFLAGVARIABLE(LuauTrackInteriorFreeTablesOnScope)
 LUAU_FASTFLAGVARIABLE(LuauPrecalculateMutatedFreeTypes2)
-LUAU_FASTFLAGVARIABLE(DebugLuauGreedyGeneralization)
-LUAU_FASTFLAG(LuauSearchForRefineableType)
-LUAU_FASTFLAG(LuauDeprecatedAttribute)
-LUAU_FASTFLAG(LuauBidirectionalInferenceCollectIndexerTypes)
-LUAU_FASTFLAG(LuauNewTypeFunReductionChecks2)
 
 namespace Luau
 {
@@ -331,7 +328,6 @@ ConstraintSolver::ConstraintSolver(
     NotNull<TypeFunctionRuntime> typeFunctionRuntime,
     NotNull<Scope> rootScope,
     std::vector<NotNull<Constraint>> constraints,
-    NotNull<DenseHashMap<Scope*, TypeId>> scopeToFunction,
     ModuleName moduleName,
     NotNull<ModuleResolver> moduleResolver,
     std::vector<RequireCycle> requireCycles,
@@ -345,7 +341,6 @@ ConstraintSolver::ConstraintSolver(
     , simplifier(simplifier)
     , typeFunctionRuntime(typeFunctionRuntime)
     , constraints(std::move(constraints))
-    , scopeToFunction(scopeToFunction)
     , rootScope(rootScope)
     , currentModuleName(std::move(moduleName))
     , dfg(dfg)
@@ -367,12 +362,6 @@ ConstraintSolver::ConstraintSolver(
             {
                 auto [refCount, _] = unresolvedConstraints.try_insert(ty, 0);
                 refCount += 1;
-
-                if (FFlag::DebugLuauGreedyGeneralization)
-                {
-                    auto [it, fresh] = mutatedFreeTypeToConstraint.try_emplace(ty, DenseHashSet<const Constraint*>{nullptr});
-                    it->second.insert(c.get());
-                }
             }
             maybeMutatedFreeTypes.emplace(c, maybeMutatedTypesPerConstraint);
         }
@@ -464,9 +453,6 @@ void ConstraintSolver::run()
                 snapshot = logger->prepareStepSnapshot(rootScope, c, force, unsolvedConstraints);
             }
 
-            if (FFlag::DebugLuauAssertOnForcedConstraint)
-                LUAU_ASSERT(!force);
-
             bool success = tryDispatch(c, force);
 
             progress |= success;
@@ -481,21 +467,12 @@ void ConstraintSolver::run()
                     const auto maybeMutated = maybeMutatedFreeTypes.find(c);
                     if (maybeMutated != maybeMutatedFreeTypes.end())
                     {
-                        DenseHashSet<TypeId> seen{nullptr};
                         for (auto ty : maybeMutated->second)
                         {
                             // There is a high chance that this type has been rebound
                             // across blocked types, rebound free types, pending
                             // expansion types, etc, so we need to follow it.
                             ty = follow(ty);
-
-                            if (FFlag::DebugLuauGreedyGeneralization)
-                            {
-                                if (seen.contains(ty))
-                                    continue;
-                                seen.insert(ty);
-                            }
-
                             size_t& refCount = unresolvedConstraints[ty];
                             if (refCount > 0)
                                 refCount -= 1;
@@ -507,9 +484,6 @@ void ConstraintSolver::run()
                             // refcount to be 1 or 0.
                             if (refCount <= 1)
                                 unblock(ty, Location{});
-
-                            if (FFlag::DebugLuauGreedyGeneralization && refCount == 0)
-                                generalizeOneType(ty);
                         }
                     }
                 }
@@ -626,152 +600,16 @@ bool ConstraintSolver::isDone() const
     return unsolvedConstraints.empty();
 }
 
-struct TypeSearcher : TypeVisitor
+namespace
 {
-    TypeId needle;
-    Polarity current = Polarity::Positive;
 
-    size_t count = 0;
-    Polarity result = Polarity::None;
-
-    explicit TypeSearcher(TypeId needle)
-        : TypeSearcher(needle, Polarity::Positive)
-    {}
-
-    explicit TypeSearcher(TypeId needle, Polarity initialPolarity)
-        : needle(needle)
-        , current(initialPolarity)
-    {}
-
-    bool visit(TypeId ty) override
-    {
-        if (ty == needle)
-        {
-            ++count;
-            result = Polarity(size_t(result) | size_t(current));
-        }
-
-        return true;
-    }
-
-    void flip()
-    {
-        switch (current)
-        {
-            case Polarity::Positive:
-                current = Polarity::Negative;
-                break;
-            case Polarity::Negative:
-                current = Polarity::Positive;
-                break;
-            default:
-                break;
-        }
-    }
-
-    bool visit(TypeId ty, const FunctionType& ft) override
-    {
-        flip();
-        traverse(ft.argTypes);
-
-        flip();
-        traverse(ft.retTypes);
-
-        return false;
-    }
-
-    // bool visit(TypeId ty, const TableType& tt) override
-    // {
-
-    // }
-
-    bool visit(TypeId ty, const ClassType&) override
-    {
-        return false;
-    }
+struct TypeAndLocation
+{
+    TypeId typeId;
+    Location location;
 };
 
-void ConstraintSolver::generalizeOneType(TypeId ty)
-{
-    ty = follow(ty);
-    const FreeType* freeTy = get<FreeType>(ty);
-
-    std::string saveme = toString(ty, opts);
-
-    // Some constraints (like prim) will also replace a free type with something
-    // concrete. If so, our work is already done.
-    if (!freeTy)
-        return;
-
-    NotNull<Scope> tyScope{freeTy->scope};
-
-    // TODO: If freeTy occurs within the enclosing function's type, we need to
-    // check to see whether this type should instead be generic.
-
-    TypeId newBound = follow(freeTy->upperBound);
-
-    TypeId* functionTyPtr = nullptr;
-    while (true)
-    {
-        functionTyPtr = scopeToFunction->find(tyScope);
-        if (functionTyPtr || !tyScope->parent)
-            break;
-        else if (tyScope->parent)
-            tyScope = NotNull{tyScope->parent.get()};
-        else
-            break;
-    }
-
-    if (ty == newBound)
-        ty = builtinTypes->unknownType;
-
-    if (!functionTyPtr)
-    {
-        asMutable(ty)->reassign(Type{BoundType{follow(freeTy->upperBound)}});
-    }
-    else
-    {
-        const TypeId functionTy = follow(*functionTyPtr);
-        FunctionType* const function = getMutable<FunctionType>(functionTy);
-        LUAU_ASSERT(function);
-
-        TypeSearcher ts{ty};
-        ts.traverse(functionTy);
-
-        const TypeId upperBound = follow(freeTy->upperBound);
-        const TypeId lowerBound = follow(freeTy->lowerBound);
-
-        switch (ts.result)
-        {
-            case Polarity::None:
-                asMutable(ty)->reassign(Type{BoundType{upperBound}});
-                break;
-
-            case Polarity::Negative:
-            case Polarity::Mixed:
-                if (get<UnknownType>(upperBound) && ts.count > 1)
-                {
-                    asMutable(ty)->reassign(Type{GenericType{tyScope}});
-                    function->generics.emplace_back(ty);
-                }
-                else
-                    asMutable(ty)->reassign(Type{BoundType{upperBound}});
-                break;
-
-            case Polarity::Positive:
-                if (get<UnknownType>(lowerBound) && ts.count > 1)
-                {
-                    asMutable(ty)->reassign(Type{GenericType{tyScope}});
-                    function->generics.emplace_back(ty);
-                }
-                else
-                    asMutable(ty)->reassign(Type{BoundType{lowerBound}});
-                break;
-            default:
-                LUAU_ASSERT(!"Unreachable");
-        }
-    }
-}
+} // namespace
 
 void ConstraintSolver::bind(NotNull<const Constraint> constraint, TypeId ty, TypeId boundTo)
 {
@@ -905,25 +743,26 @@ bool ConstraintSolver::tryDispatch(const GeneralizationConstraint& c, NotNull<co
     else if (get<PendingExpansionType>(generalizedType))
         return block(generalizedType, constraint);
 
+    std::optional<QuantifierResult> generalized;
+
     std::optional<TypeId> generalizedTy = generalize(NotNull{arena}, builtinTypes, constraint->scope, generalizedTypes, c.sourceType);
-    if (!generalizedTy)
+    if (generalizedTy)
+        generalized = QuantifierResult{*generalizedTy}; // FIXME insertedGenerics and insertedGenericPacks
+    else
         reportError(CodeTooComplex{}, constraint->location);
 
-    if (generalizedTy)
+    if (generalized)
     {
         if (get<BlockedType>(generalizedType))
-            bind(constraint, generalizedType, *generalizedTy);
+            bind(constraint, generalizedType, generalized->result);
         else
-            unify(constraint, generalizedType, *generalizedTy);
+            unify(constraint, generalizedType, generalized->result);
 
-        if (FFlag::LuauDeprecatedAttribute)
-        {
-            if (FunctionType* fty = getMutable<FunctionType>(follow(generalizedType)))
-            {
-                if (c.hasDeprecatedAttribute)
-                    fty->isDeprecatedFunction = true;
-            }
-        }
+        for (auto [free, gen] : generalized->insertedGenerics.pairings)
+            unify(constraint, free, gen);
+
+        for (auto [free, gen] : generalized->insertedGenericPacks.pairings)
+            unify(constraint, free, gen);
     }
     else
     {
@@ -937,12 +776,12 @@ bool ConstraintSolver::tryDispatch(const GeneralizationConstraint& c, NotNull<co
         // clang-tidy doesn't understand this is safe.
         if (constraint->scope->interiorFreeTypes)
             for (TypeId ty : *constraint->scope->interiorFreeTypes) // NOLINT(bugprone-unchecked-optional-access)
-                generalize(NotNull{arena}, builtinTypes, constraint->scope, generalizedTypes, ty);
+                generalize(NotNull{arena}, builtinTypes, constraint->scope, generalizedTypes, ty, /* avoidSealingTables */ false);
     }
     else
     {
         for (TypeId ty : c.interiorTypes)
-            generalize(NotNull{arena}, builtinTypes, constraint->scope, generalizedTypes, ty);
+            generalize(NotNull{arena}, builtinTypes, constraint->scope, generalizedTypes, ty, /* avoidSealingTables */ false);
     }
 
 
@@ -1331,9 +1170,12 @@ bool ConstraintSolver::tryDispatch(const TypeAliasExpansionConstraint& c, NotNul
             target = follow(instantiated);
         }
 
-        // This is a new type - redefine the location.
-        ttv->definitionLocation = constraint->location;
-        ttv->definitionModuleName = currentModuleName;
+        if (FFlag::LuauNewSolverPopulateTableLocations)
+        {
+            // This is a new type - redefine the location.
+            ttv->definitionLocation = constraint->location;
+            ttv->definitionModuleName = currentModuleName;
+        }
 
         ttv->instantiatedTypeParams = typeArguments;
         ttv->instantiatedTypePackParams = packArguments;
@@ -1353,29 +1195,15 @@ void ConstraintSolver::fillInDiscriminantTypes(NotNull<const Constraint> constra
         if (!ty)
             continue;
 
-        if (FFlag::LuauSearchForRefineableType)
+        // If the discriminant type has been transmuted, we need to unblock them.
+        if (!isBlocked(*ty))
         {
-            if (isBlocked(*ty))
-                // We bind any unused discriminants to the `*no-refine*` type indicating that it can be safely ignored.
-                emplaceType<BoundType>(asMutable(follow(*ty)), builtinTypes->noRefineType);
-
-            // We also need to unconditionally unblock these types, otherwise
-            // you end up with funky looking "Blocked on *no-refine*."
             unblock(*ty, constraint->location);
+            continue;
         }
-        else
-        {
 
-            // If the discriminant type has been transmuted, we need to unblock them.
-            if (!isBlocked(*ty))
-            {
-                unblock(*ty, constraint->location);
-                continue;
-            }
-
-            // We bind any unused discriminants to the `*no-refine*` type indicating that it can be safely ignored.
-            emplaceType<BoundType>(asMutable(follow(*ty)), builtinTypes->noRefineType);
-        }
+        // We bind any unused discriminants to the `*no-refine*` type indicating that it can be safely ignored.
+        emplaceType<BoundType>(asMutable(follow(*ty)), builtinTypes->noRefineType);
     }
 }
 
@@ -1385,24 +1213,17 @@ bool ConstraintSolver::tryDispatch(const FunctionCallConstraint& c, NotNull<cons
     TypePackId argsPack = follow(c.argsPack);
     TypePackId result = follow(c.result);
 
-    if (FFlag::DebugLuauGreedyGeneralization)
+    if (isBlocked(fn) || hasUnresolvedConstraints(fn))
     {
-        if (isBlocked(fn))
-            return block(c.fn, constraint);
-    }
-    else
-    {
-        if (isBlocked(fn) || hasUnresolvedConstraints(fn))
-        {
-            return block(c.fn, constraint);
-        }
+        return block(c.fn, constraint);
     }
 
     if (get<AnyType>(fn))
     {
         emplaceTypePack<BoundTypePack>(asMutable(c.result), builtinTypes->anyTypePack);
         unblock(c.result, constraint->location);
-        fillInDiscriminantTypes(constraint, c.discriminantTypes);
+        if (FFlag::LuauAlwaysFillInFunctionCallDiscriminantTypes)
+            fillInDiscriminantTypes(constraint, c.discriminantTypes);
         return true;
     }
 
@@ -1410,14 +1231,16 @@ bool ConstraintSolver::tryDispatch(const FunctionCallConstraint& c, NotNull<cons
     if (get<ErrorType>(fn))
     {
         bind(constraint, c.result, builtinTypes->errorRecoveryTypePack());
-        fillInDiscriminantTypes(constraint, c.discriminantTypes);
+        if (FFlag::LuauAlwaysFillInFunctionCallDiscriminantTypes)
+            fillInDiscriminantTypes(constraint, c.discriminantTypes);
         return true;
     }
 
     if (get<NeverType>(fn))
     {
         bind(constraint, c.result, builtinTypes->neverTypePack);
-        fillInDiscriminantTypes(constraint, c.discriminantTypes);
+        if (FFlag::LuauAlwaysFillInFunctionCallDiscriminantTypes)
+            fillInDiscriminantTypes(constraint, c.discriminantTypes);
         return true;
     }
 
@@ -1498,7 +1321,30 @@ bool ConstraintSolver::tryDispatch(const FunctionCallConstraint& c, NotNull<cons
             emplace<FreeTypePack>(constraint, c.result, constraint->scope);
     }
 
-    fillInDiscriminantTypes(constraint, c.discriminantTypes);
+    if (FFlag::LuauAlwaysFillInFunctionCallDiscriminantTypes)
+    {
+        fillInDiscriminantTypes(constraint, c.discriminantTypes);
+    }
+    else
+    {
+        // NOTE: This is the body of the `fillInDiscriminantTypes` helper.
+        for (std::optional<TypeId> ty : c.discriminantTypes)
+        {
+            if (!ty)
+                continue;
+
+            // If the discriminant type has been transmuted, we need to unblock them.
+            if (!isBlocked(*ty))
+            {
+                unblock(*ty, constraint->location);
+                continue;
+            }
+
+            // We bind any unused discriminants to the `*no-refine*` type indicating that it can be safely ignored.
+            emplaceType<BoundType>(asMutable(follow(*ty)), builtinTypes->noRefineType);
+        }
+    }
+
 
     OverloadResolver resolver{
         builtinTypes,
@@ -1564,43 +1410,6 @@ static AstExpr* unwrapGroup(AstExpr* expr)
     return expr;
 }
 
-struct ContainsGenerics : public TypeOnceVisitor
-{
-    DenseHashSet<const void*> generics{nullptr};
-
-    bool found = false;
-
-    bool visit(TypeId ty) override
-    {
-        return !found;
-    }
-
-    bool visit(TypeId ty, const GenericType&) override
-    {
-        found |= generics.contains(ty);
-        return true;
-    }
-
-    bool visit(TypeId ty, const TypeFunctionInstanceType&) override
-    {
-        return !found;
-    }
-
-    bool visit(TypePackId tp, const GenericTypePack&) override
-    {
-        found |= generics.contains(tp);
-        return !found;
-    }
-
-    bool hasGeneric(TypeId ty)
-    {
-        traverse(ty);
-        auto ret = found;
-        found = false;
-        return ret;
-    }
-};
-
 bool ConstraintSolver::tryDispatch(const FunctionCheckConstraint& c, NotNull<const Constraint> constraint)
 {
     TypeId fn = follow(c.fn);
@@ -1643,49 +1452,36 @@ bool ConstraintSolver::tryDispatch(const FunctionCheckConstraint& c, NotNull<con
     DenseHashMap<TypeId, TypeId> replacements{nullptr};
     DenseHashMap<TypePackId, TypePackId> replacementPacks{nullptr};
 
-    ContainsGenerics containsGenerics;
-
     for (auto generic : ftv->generics)
-    {
         replacements[generic] = builtinTypes->unknownType;
-        if (FFlag::LuauBidirectionalInferenceCollectIndexerTypes)
-            containsGenerics.generics.insert(generic);
-    }
 
     for (auto genericPack : ftv->genericPacks)
-    {
         replacementPacks[genericPack] = builtinTypes->unknownTypePack;
-        if (FFlag::LuauBidirectionalInferenceCollectIndexerTypes)
-            containsGenerics.generics.insert(genericPack);
-    }
 
     // If the type of the function has generics, we don't actually want to push any of the generics themselves
     // into the argument types as expected types because this creates an unnecessary loop. Instead, we want to
     // replace these types with `unknown` (and `...unknown`) to keep any structure but not create the cycle.
-    if (!FFlag::LuauBidirectionalInferenceCollectIndexerTypes)
+    if (!replacements.empty() || !replacementPacks.empty())
     {
-        if (!replacements.empty() || !replacementPacks.empty())
+        Replacer replacer{arena, std::move(replacements), std::move(replacementPacks)};
+
+        std::optional<TypeId> res = replacer.substitute(fn);
+        if (res)
         {
-            Replacer replacer{arena, std::move(replacements), std::move(replacementPacks)};
-
-            std::optional<TypeId> res = replacer.substitute(fn);
-            if (res)
+            if (*res != fn)
             {
-                if (*res != fn)
-                {
-                    FunctionType* ftvMut = getMutable<FunctionType>(*res);
-                    LUAU_ASSERT(ftvMut);
-                    ftvMut->generics.clear();
-                    ftvMut->genericPacks.clear();
-                }
-
-                fn = *res;
-                ftv = get<FunctionType>(*res);
-                LUAU_ASSERT(ftv);
-
-                // we've potentially copied type functions here, so we need to reproduce their reduce constraint.
-                reproduceConstraints(constraint->scope, constraint->location, replacer);
+                FunctionType* ftvMut = getMutable<FunctionType>(*res);
+                LUAU_ASSERT(ftvMut);
+                ftvMut->generics.clear();
+                ftvMut->genericPacks.clear();
             }
+
+            fn = *res;
+            ftv = get<FunctionType>(*res);
+            LUAU_ASSERT(ftv);
+
+            // we've potentially copied type functions here, so we need to reproduce their reduce constraint.
+            reproduceConstraints(constraint->scope, constraint->location, replacer);
         }
     }
 
@@ -1704,10 +1500,6 @@ bool ConstraintSolver::tryDispatch(const FunctionCheckConstraint& c, NotNull<con
 
         (*c.astExpectedTypes)[expr] = expectedArgTy;
 
-        // Generic types are skipped over entirely, for now.
-        if (FFlag::LuauBidirectionalInferenceCollectIndexerTypes && containsGenerics.hasGeneric(expectedArgTy))
-            continue;
-
         const FunctionType* expectedLambdaTy = get<FunctionType>(expectedArgTy);
         const FunctionType* lambdaTy = get<FunctionType>(actualArgTy);
         const AstExprFunction* lambdaExpr = expr->as<AstExprFunction>();
@@ -1735,11 +1527,8 @@ bool ConstraintSolver::tryDispatch(const FunctionCheckConstraint& c, NotNull<con
         else if (expr->is<AstExprTable>())
         {
             Unifier2 u2{arena, builtinTypes, constraint->scope, NotNull{&iceReporter}};
-            Subtyping sp{builtinTypes, arena, simplifier, normalizer, typeFunctionRuntime, NotNull{&iceReporter}};
             std::vector<TypeId> toBlock;
-            (void)matchLiteralType(
-                c.astTypes, c.astExpectedTypes, builtinTypes, arena, NotNull{&u2}, NotNull{&sp}, expectedArgTy, actualArgTy, expr, toBlock
-            );
+            (void)matchLiteralType(c.astTypes, c.astExpectedTypes, builtinTypes, arena, NotNull{&u2}, expectedArgTy, actualArgTy, expr, toBlock);
             LUAU_ASSERT(toBlock.empty());
         }
     }
@@ -1763,9 +1552,8 @@ bool ConstraintSolver::tryDispatch(const TableCheckConstraint& c, NotNull<const
         return false;
 
     Unifier2 u2{arena, builtinTypes, constraint->scope, NotNull{&iceReporter}};
-    Subtyping sp{builtinTypes, arena, simplifier, normalizer, typeFunctionRuntime, NotNull{&iceReporter}};
     std::vector<TypeId> toBlock;
-    (void)matchLiteralType(c.astTypes, c.astExpectedTypes, builtinTypes, arena, NotNull{&u2}, NotNull{&sp}, c.expectedType, c.exprType, c.table, toBlock);
+    (void)matchLiteralType(c.astTypes, c.astExpectedTypes, builtinTypes, arena, NotNull{&u2}, c.expectedType, c.exprType, c.table, toBlock);
     LUAU_ASSERT(toBlock.empty());
     return true;
 }
@@ -2124,7 +1912,7 @@ bool ConstraintSolver::tryDispatch(const AssignPropConstraint& c, NotNull<const
         bind(
             constraint,
             c.propType,
-            isIndex ? arena->addType(UnionType{{propTy, builtinTypes->nilType}}) : propTy
+            isIndex && FFlag::LuauAllowNilAssignmentToIndexer ? arena->addType(UnionType{{propTy, builtinTypes->nilType}}) : propTy
         );
         unify(constraint, rhsType, propTy);
         return true;
@@ -2222,7 +2010,8 @@ bool ConstraintSolver::tryDispatch(const AssignIndexConstraint& c, NotNull<const
             bind(
                 constraint,
                 c.propType,
-                arena->addType(UnionType{{lhsTable->indexer->indexResultType, builtinTypes->nilType}})
+                FFlag::LuauAllowNilAssignmentToIndexer ? arena->addType(UnionType{{lhsTable->indexer->indexResultType, builtinTypes->nilType}})
+                                                       : lhsTable->indexer->indexResultType
             );
             return true;
         }
@@ -2275,7 +2064,8 @@ bool ConstraintSolver::tryDispatch(const AssignIndexConstraint& c, NotNull<const
                 bind(
                     constraint,
                     c.propType,
-                    arena->addType(UnionType{{lhsClass->indexer->indexResultType, builtinTypes->nilType}})
+                    FFlag::LuauAllowNilAssignmentToIndexer ? arena->addType(UnionType{{lhsClass->indexer->indexResultType, builtinTypes->nilType}})
+                                                           : lhsClass->indexer->indexResultType
                 );
                 return true;
             }
@@ -2419,18 +2209,11 @@ bool ConstraintSolver::tryDispatch(const ReduceConstraint& c, NotNull<const Cons
     for (TypePackId r : result.reducedPacks)
         unblock(r, constraint->location);
 
-    if (FFlag::LuauNewTypeFunReductionChecks2)
-    {
-        for (TypeId ity : result.irreducibleTypes)
-            uninhabitedTypeFunctions.insert(ity);
-    }
-
     bool reductionFinished = result.blockedTypes.empty() && result.blockedPacks.empty();
 
     ty = follow(ty);
-
     // If we couldn't reduce this type function, stick it in the set!
-    if (get<TypeFunctionInstanceType>(ty) && (!FFlag::LuauNewTypeFunReductionChecks2 || !result.irreducibleTypes.find(ty)))
+    if (get<TypeFunctionInstanceType>(ty))
         typeFunctionsToFinalize[ty] = constraint;
 
     if (force || reductionFinished)
@@ -3330,27 +3113,9 @@ void ConstraintSolver::shiftReferences(TypeId source, TypeId target)
 
     auto [targetRefs, _] = unresolvedConstraints.try_insert(target, 0);
     targetRefs += count;
-
-    // Any constraint that might have mutated source may now mutate target
-
-    if (FFlag::DebugLuauGreedyGeneralization)
-    {
-        auto it = mutatedFreeTypeToConstraint.find(source);
-        if (it != mutatedFreeTypeToConstraint.end())
-        {
-            auto [it2, fresh] = mutatedFreeTypeToConstraint.try_emplace(target, DenseHashSet<const Constraint*>{nullptr});
-            for (const Constraint* constraint : it->second)
-            {
-                it2->second.insert(constraint);
-
-                auto [it3, fresh2] = maybeMutatedFreeTypes.try_emplace(NotNull{constraint}, DenseHashSet<TypeId>{nullptr});
-                it3->second.insert(target);
-            }
-        }
-    }
 }
 
-std::optional<TypeId> ConstraintSolver::generalizeFreeType(NotNull<Scope> scope, TypeId type)
+std::optional<TypeId> ConstraintSolver::generalizeFreeType(NotNull<Scope> scope, TypeId type, bool avoidSealingTables)
 {
     TypeId t = follow(type);
     if (get<FreeType>(t))
@@ -3365,7 +3130,7 @@ std::optional<TypeId> ConstraintSolver::generalizeFreeType(NotNull<Scope> scope,
         // that until all constraint generation is complete.
     }
 
-    return generalize(NotNull{arena}, builtinTypes, scope, generalizedTypes, type);
+    return generalize(NotNull{arena}, builtinTypes, scope, generalizedTypes, type, avoidSealingTables);
 }
 
 bool ConstraintSolver::hasUnresolvedConstraints(TypeId ty)

Analysis/src/DataFlowGraph.cpp

@@ -82,6 +82,12 @@ std::optional<DefId> DataFlowGraph::getDefOptional(const AstExpr* expr) const
     return NotNull{*def};
 }
 
+std::optional<DefId> DataFlowGraph::getRValueDefForCompoundAssign(const AstExpr* expr) const
+{
+    auto def = compoundAssignDefs.find(expr);
+    return def ? std::optional<DefId>(*def) : std::nullopt;
+}
+
 DefId DataFlowGraph::getDef(const AstLocal* local) const
 {
     auto def = localDefs.find(local);
@@ -905,17 +911,8 @@ DataFlowResult DataFlowGraphBuilder::visitExpr(AstExprCall* c)
     for (AstExpr* arg : c->args)
         visitExpr(arg);
 
-    // We treat function calls as "subscripted" as they could potentially
-    // return a subscripted value, consider:
-    //
-    //  local function foo(tbl: {[string]: woof)
-    //      return tbl["foobarbaz"]
-    //  end
-    //
-    //  local v = foo({})
-    //
-    // We want to consider `v` to be subscripted here.
-    return {defArena->freshCell(/*subscripted=*/true)};
+    // calls should be treated as subscripted.
+    return {defArena->freshCell(/* subscripted */ true), nullptr};
 }
 
 DataFlowResult DataFlowGraphBuilder::visitExpr(AstExprIndexName* i)
@@ -1162,8 +1159,6 @@ void DataFlowGraphBuilder::visitType(AstType* t)
         return visitType(f);
     else if (auto tyof = t->as<AstTypeTypeof>())
         return visitType(tyof);
-    else if (auto o = t->as<AstTypeOptional>())
-        return;
     else if (auto u = t->as<AstTypeUnion>())
         return visitType(u);
     else if (auto i = t->as<AstTypeIntersection>())

Analysis/src/EmbeddedBuiltinDefinitions.cpp

@@ -1,6 +1,10 @@
 // This file is part of the Luau programming language and is licensed under MIT License; see LICENSE.txt for details
 #include "Luau/BuiltinDefinitions.h"
 
+LUAU_FASTFLAG(LuauBufferBitMethods2)
+LUAU_FASTFLAG(LuauVector2Constructor)
+LUAU_FASTFLAGVARIABLE(LuauDebugInfoDefn)
+
 namespace Luau
 {
 
@@ -213,6 +217,15 @@ declare debug: {
 
 )BUILTIN_SRC";
 
+static const std::string kBuiltinDefinitionDebugSrc_DEPRECATED = R"BUILTIN_SRC(
+
+declare debug: {
+    info: (<R...>(thread: thread, level: number, options: string) -> R...) & (<R...>(level: number, options: string) -> R...) & (<A..., R1..., R2...>(func: (A...) -> R1..., options: string) -> R2...),
+    traceback: ((message: string?, level: number?) -> string) & ((thread: thread, message: string?, level: number?) -> string),
+}
+
+)BUILTIN_SRC";
+
 static const std::string kBuiltinDefinitionUtf8Src = R"BUILTIN_SRC(
 
 declare utf8: {
@@ -226,6 +239,37 @@ declare utf8: {
 
 )BUILTIN_SRC";
 
+static const std::string kBuiltinDefinitionBufferSrc_DEPRECATED = R"BUILTIN_SRC(
+--- Buffer API
+declare buffer: {
+    create: @checked (size: number) -> buffer,
+    fromstring: @checked (str: string) -> buffer,
+    tostring: @checked (b: buffer) -> string,
+    len: @checked (b: buffer) -> number,
+    copy: @checked (target: buffer, targetOffset: number, source: buffer, sourceOffset: number?, count: number?) -> (),
+    fill: @checked (b: buffer, offset: number, value: number, count: number?) -> (),
+    readi8: @checked (b: buffer, offset: number) -> number,
+    readu8: @checked (b: buffer, offset: number) -> number,
+    readi16: @checked (b: buffer, offset: number) -> number,
+    readu16: @checked (b: buffer, offset: number) -> number,
+    readi32: @checked (b: buffer, offset: number) -> number,
+    readu32: @checked (b: buffer, offset: number) -> number,
+    readf32: @checked (b: buffer, offset: number) -> number,
+    readf64: @checked (b: buffer, offset: number) -> number,
+    writei8: @checked (b: buffer, offset: number, value: number) -> (),
+    writeu8: @checked (b: buffer, offset: number, value: number) -> (),
+    writei16: @checked (b: buffer, offset: number, value: number) -> (),
+    writeu16: @checked (b: buffer, offset: number, value: number) -> (),
+    writei32: @checked (b: buffer, offset: number, value: number) -> (),
+    writeu32: @checked (b: buffer, offset: number, value: number) -> (),
+    writef32: @checked (b: buffer, offset: number, value: number) -> (),
+    writef64: @checked (b: buffer, offset: number, value: number) -> (),
+    readstring: @checked (b: buffer, offset: number, count: number) -> string,
+    writestring: @checked (b: buffer, offset: number, value: string, count: number?) -> (),
+}
+
+)BUILTIN_SRC";
+
 static const std::string kBuiltinDefinitionBufferSrc = R"BUILTIN_SRC(
 --- Buffer API
 declare buffer: {
@@ -259,6 +303,36 @@ declare buffer: {
 
 )BUILTIN_SRC";
 
+static const std::string kBuiltinDefinitionVectorSrc_NoVector2Ctor_DEPRECATED = R"BUILTIN_SRC(
+
+-- While vector would have been better represented as a built-in primitive type, type solver class handling covers most of the properties
+declare class vector
+    x: number
+    y: number
+    z: number
+end
+
+declare vector: {
+    create: @checked (x: number, y: number, z: number) -> vector,
+    magnitude: @checked (vec: vector) -> number,
+    normalize: @checked (vec: vector) -> vector,
+    cross: @checked (vec1: vector, vec2: vector) -> vector,
+    dot: @checked (vec1: vector, vec2: vector) -> number,
+    angle: @checked (vec1: vector, vec2: vector, axis: vector?) -> number,
+    floor: @checked (vec: vector) -> vector,
+    ceil: @checked (vec: vector) -> vector,
+    abs: @checked (vec: vector) -> vector,
+    sign: @checked (vec: vector) -> vector,
+    clamp: @checked (vec: vector, min: vector, max: vector) -> vector,
+    max: @checked (vector, ...vector) -> vector,
+    min: @checked (vector, ...vector) -> vector,
+
+    zero: vector,
+    one: vector,
+}
+
+)BUILTIN_SRC";
+
 static const std::string kBuiltinDefinitionVectorSrc = R"BUILTIN_SRC(
 
 -- While vector would have been better represented as a built-in primitive type, type solver class handling covers most of the properties
@@ -298,91 +372,17 @@ std::string getBuiltinDefinitionSource()
     result += kBuiltinDefinitionOsSrc;
     result += kBuiltinDefinitionCoroutineSrc;
     result += kBuiltinDefinitionTableSrc;
-    result += kBuiltinDefinitionDebugSrc;
+    result += FFlag::LuauDebugInfoDefn ? kBuiltinDefinitionDebugSrc : kBuiltinDefinitionDebugSrc_DEPRECATED;
     result += kBuiltinDefinitionUtf8Src;
-    result += kBuiltinDefinitionBufferSrc;
-    result += kBuiltinDefinitionVectorSrc;
+
+    result += FFlag::LuauBufferBitMethods2 ? kBuiltinDefinitionBufferSrc : kBuiltinDefinitionBufferSrc_DEPRECATED;
+
+    if (FFlag::LuauVector2Constructor)
+        result += kBuiltinDefinitionVectorSrc;
+    else
+        result += kBuiltinDefinitionVectorSrc_NoVector2Ctor_DEPRECATED;
 
     return result;
 }
 
-// TODO: split into separate tagged unions when the new solver can appropriately handle that.
-static const std::string kBuiltinDefinitionTypesSrc = R"BUILTIN_SRC(
-
-export type type = {
-    tag: "nil" | "unknown" | "never" | "any" | "boolean" | "number" | "string" | "buffer" | "thread" |
-         "singleton" | "negation" | "union" | "intesection" | "table" | "function" | "class" | "generic",
-
-    is: (self: type, arg: string) -> boolean,
-
-    -- for singleton type
-    value: (self: type) -> (string | boolean | nil),
-
-    -- for negation type
-    inner: (self: type) -> type,
-
-    -- for union and intersection types
-    components: (self: type) -> {type},
-
-    -- for table type
-    setproperty: (self: type, key: type, value: type?) -> (),
-    setreadproperty: (self: type, key: type, value: type?) -> (),
-    setwriteproperty: (self: type, key: type, value: type?) -> (),
-    readproperty: (self: type, key: type) -> type?,
-    writeproperty: (self: type, key: type) -> type?,
-    properties: (self: type) -> { [type]: { read: type?, write: type? } },
-    setindexer: (self: type, index: type, result: type) -> (),
-    setreadindexer: (self: type, index: type, result: type) -> (),
-    setwriteindexer: (self: type, index: type, result: type) -> (),
-    indexer: (self: type) -> { index: type, readresult: type, writeresult: type }?,
-    readindexer: (self: type) -> { index: type, result: type }?,
-    writeindexer: (self: type) -> { index: type, result: type }?,
-    setmetatable: (self: type, arg: type) -> (),
-    metatable: (self: type) -> type?,
-
-    -- for function type
-    setparameters: (self: type, head: {type}?, tail: type?) -> (),
-    parameters: (self: type) -> { head: {type}?, tail: type? },
-    setreturns: (self: type, head: {type}?, tail: type? ) -> (),
-    returns: (self: type) -> { head: {type}?, tail: type? },
-    setgenerics: (self: type, {type}?) -> (),
-    generics: (self: type) -> {type},
-
-    -- for class type
-    -- 'properties', 'metatable', 'indexer', 'readindexer' and 'writeindexer' are shared with table type
-    readparent: (self: type) -> type?,
-    writeparent: (self: type) -> type?,
-
-    -- for generic type
-    name: (self: type) -> string?,
-    ispack: (self: type) -> boolean,
-}
-
-declare types: {
-    unknown: type,
-    never: type,
-    any: type,
-    boolean: type,
-    number: type,
-    string: type,
-    thread: type,
-    buffer: type,
-
-    singleton: @checked (arg: string | boolean | nil) -> type,
-    generic: @checked (name: string, ispack: boolean?) -> type,
-    negationof: @checked (arg: type) -> type,
-    unionof: @checked (...type) -> type,
-    intersectionof: @checked (...type) -> type,
-    newtable: @checked (props: {[type]: type} | {[type]: { read: type, write: type } } | nil, indexer: { index: type, readresult: type, writeresult: type }?, metatable: type?) -> type,
-    newfunction: @checked (parameters: { head: {type}?, tail: type? }?, returns: { head: {type}?, tail: type? }?, generics: {type}?) -> type,
-    copy: @checked (arg: type) -> type,
-}
-
-)BUILTIN_SRC";
-
-std::string getTypeFunctionDefinitionSource()
-{
-    return kBuiltinDefinitionTypesSrc;
-}
-
 } // namespace Luau

Analysis/src/Error.cpp

@@ -8,7 +8,6 @@
 #include "Luau/StringUtils.h"
 #include "Luau/ToString.h"
 #include "Luau/Type.h"
-#include "Luau/TypeChecker2.h"
 #include "Luau/TypeFunction.h"
 
 #include <optional>
@@ -18,7 +17,6 @@
 #include <unordered_set>
 
 LUAU_FASTINTVARIABLE(LuauIndentTypeMismatchMaxTypeLength, 10)
-LUAU_FASTFLAG(LuauNonStrictFuncDefErrorFix)
 
 static std::string wrongNumberOfArgsString(
     size_t expectedCount,
@@ -118,10 +116,7 @@ struct ErrorConverter
             size_t luauIndentTypeMismatchMaxTypeLength = size_t(FInt::LuauIndentTypeMismatchMaxTypeLength);
             if (givenType.length() <= luauIndentTypeMismatchMaxTypeLength || wantedType.length() <= luauIndentTypeMismatchMaxTypeLength)
                 return "Type " + given + " could not be converted into " + wanted;
-            if (FFlag::LuauImproveTypePathsInErrors)
-                return "Type\n\t" + given + "\ncould not be converted into\n\t" + wanted;
-            else
-                return "Type\n    " + given + "\ncould not be converted into\n    " + wanted;
+            return "Type\n    " + given + "\ncould not be converted into\n    " + wanted;
         };
 
         if (givenTypeName == wantedTypeName)
@@ -756,15 +751,8 @@ struct ErrorConverter
 
     std::string operator()(const NonStrictFunctionDefinitionError& e) const
     {
-        if (FFlag::LuauNonStrictFuncDefErrorFix && e.functionName.empty())
-        {
-            return "Argument " + e.argument + " with type '" + toString(e.argumentType) + "' is used in a way that will run time error";
-        }
-        else
-        {
-            return "Argument " + e.argument + " with type '" + toString(e.argumentType) + "' in function '" + e.functionName +
-                   "' is used in a way that will run time error";
-        }
+        return "Argument " + e.argument + " with type '" + toString(e.argumentType) + "' in function '" + e.functionName +
+               "' is used in a way that will run time error";
     }
 
     std::string operator()(const PropertyAccessViolation& e) const

Analysis/src/FileResolver.cpp

@@ -1,172 +0,0 @@
-// This file is part of the Luau programming language and is licensed under MIT License; see LICENSE.txt for details
-#include "Luau/FileResolver.h"
-
-#include "Luau/Common.h"
-#include "Luau/StringUtils.h"
-
-#include <algorithm>
-#include <memory>
-#include <optional>
-#include <string_view>
-#include <utility>
-
-LUAU_FASTFLAGVARIABLE(LuauExposeRequireByStringAutocomplete)
-LUAU_FASTFLAGVARIABLE(LuauEscapeCharactersInRequireSuggestions)
-LUAU_FASTFLAGVARIABLE(LuauHideImpossibleRequireSuggestions)
-
-namespace Luau
-{
-
-static std::optional<RequireSuggestions> processRequireSuggestions(std::optional<RequireSuggestions> suggestions)
-{
-    if (!suggestions)
-        return suggestions;
-
-    if (FFlag::LuauEscapeCharactersInRequireSuggestions)
-    {
-        for (RequireSuggestion& suggestion : *suggestions)
-        {
-            suggestion.fullPath = escape(suggestion.fullPath);
-        }
-    }
-
-    return suggestions;
-}
-
-static RequireSuggestions makeSuggestionsFromAliases(std::vector<RequireAlias> aliases)
-{
-    RequireSuggestions result;
-    for (RequireAlias& alias : aliases)
-    {
-        RequireSuggestion suggestion;
-        suggestion.label = "@" + std::move(alias.alias);
-        suggestion.fullPath = suggestion.label;
-        suggestion.tags = std::move(alias.tags);
-        result.push_back(std::move(suggestion));
-    }
-    return result;
-}
-
-static RequireSuggestions makeSuggestionsForFirstComponent(std::unique_ptr<RequireNode> node)
-{
-    RequireSuggestions result = makeSuggestionsFromAliases(node->getAvailableAliases());
-    result.push_back(RequireSuggestion{"./", "./", {}});
-    result.push_back(RequireSuggestion{"../", "../", {}});
-    return result;
-}
-
-static RequireSuggestions makeSuggestionsFromNode(std::unique_ptr<RequireNode> node, const std::string_view path, bool isPartialPath)
-{
-    LUAU_ASSERT(!path.empty());
-
-    RequireSuggestions result;
-
-    const size_t lastSlashInPath = path.find_last_of('/');
-
-    if (lastSlashInPath != std::string_view::npos)
-    {
-        // Add a suggestion for the parent directory
-        RequireSuggestion parentSuggestion;
-        parentSuggestion.label = "..";
-
-        // TODO: after exposing require-by-string's path normalization API, this
-        // if-else can be replaced. Instead, we can simply normalize the result
-        // of inserting ".." at the end of the current path.
-        if (lastSlashInPath >= 2 && path.substr(lastSlashInPath - 2, 3) == "../")
-        {
-            parentSuggestion.fullPath = path.substr(0, lastSlashInPath + 1);
-            parentSuggestion.fullPath += "..";
-        }
-        else
-        {
-            parentSuggestion.fullPath = path.substr(0, lastSlashInPath);
-        }
-
-        result.push_back(std::move(parentSuggestion));
-    }
-
-    std::string fullPathPrefix;
-    if (isPartialPath)
-    {
-        // ./path/to/chi -> ./path/to/
-        fullPathPrefix += path.substr(0, lastSlashInPath + 1);
-    }
-    else
-    {
-        if (path.back() == '/')
-        {
-            // ./path/to/ -> ./path/to/
-            fullPathPrefix += path;
-        }
-        else
-        {
-            // ./path/to -> ./path/to/
-            fullPathPrefix += path;
-            fullPathPrefix += "/";
-        }
-    }
-
-    for (const std::unique_ptr<RequireNode>& child : node->getChildren())
-    {
-        if (!child)
-            continue;
-
-        std::string pathComponent = child->getPathComponent();
-        if (FFlag::LuauHideImpossibleRequireSuggestions)
-        {
-            // If path component contains a slash, it cannot be required by string.
-            // There's no point suggesting it.
-            if (pathComponent.find('/') != std::string::npos)
-                continue;
-        }
-
-        RequireSuggestion suggestion;
-        suggestion.label = isPartialPath || path.back() == '/' ? child->getLabel() : "/" + child->getLabel();
-        suggestion.fullPath = fullPathPrefix + std::move(pathComponent);
-        suggestion.tags = child->getTags();
-        result.push_back(std::move(suggestion));
-    }
-
-    return result;
-}
-
-std::optional<RequireSuggestions> RequireSuggester::getRequireSuggestionsImpl(const ModuleName& requirer, const std::optional<std::string>& path)
-    const
-{
-    if (!path)
-        return std::nullopt;
-
-    std::unique_ptr<RequireNode> requirerNode = getNode(requirer);
-    if (!requirerNode)
-        return std::nullopt;
-
-    const size_t slashPos = path->find_last_of('/');
-
-    if (slashPos == std::string::npos)
-        return makeSuggestionsForFirstComponent(std::move(requirerNode));
-
-    // If path already points at a Node, return the Node's children as paths.
-    if (std::unique_ptr<RequireNode> node = requirerNode->resolvePathToNode(*path))
-        return makeSuggestionsFromNode(std::move(node), *path, /* isPartialPath = */ false);
-
-    // Otherwise, recover a partial path and use this to generate suggestions.
-    if (std::unique_ptr<RequireNode> partialNode = requirerNode->resolvePathToNode(path->substr(0, slashPos)))
-        return makeSuggestionsFromNode(std::move(partialNode), *path, /* isPartialPath = */ true);
-
-    return std::nullopt;
-}
-
-std::optional<RequireSuggestions> RequireSuggester::getRequireSuggestions(const ModuleName& requirer, const std::optional<std::string>& path) const
-{
-    return processRequireSuggestions(getRequireSuggestionsImpl(requirer, path));
-}
-
-std::optional<RequireSuggestions> FileResolver::getRequireSuggestions(const ModuleName& requirer, const std::optional<std::string>& path) const
-{
-    if (!FFlag::LuauExposeRequireByStringAutocomplete)
-        return std::nullopt;
-
-    return requireSuggester ? requireSuggester->getRequireSuggestions(requirer, path) : std::nullopt;
-}
-
-} // namespace Luau

Analysis/src/Frontend.cpp

@@ -1,6 +1,7 @@
 // This file is part of the Luau programming language and is licensed under MIT License; see LICENSE.txt for details
 #include "Luau/Frontend.h"
 
+#include "Luau/AnyTypeSummary.h"
 #include "Luau/BuiltinDefinitions.h"
 #include "Luau/Clone.h"
 #include "Luau/Common.h"
@@ -46,12 +47,12 @@ LUAU_FASTFLAGVARIABLE(DebugLuauForceStrictMode)
 LUAU_FASTFLAGVARIABLE(DebugLuauForceNonStrictMode)
 LUAU_DYNAMIC_FASTFLAGVARIABLE(LuauRunCustomModuleChecks, false)
 
-LUAU_FASTFLAGVARIABLE(LuauModuleHoldsAstRoot)
+LUAU_FASTFLAGVARIABLE(LuauBetterReverseDependencyTracking)
 
-LUAU_FASTFLAGVARIABLE(LuauFixMultithreadTypecheck)
+LUAU_FASTFLAG(StudioReportLuauAny2)
+LUAU_FASTFLAGVARIABLE(LuauStoreSolverTypeOnModule)
 
 LUAU_FASTFLAGVARIABLE(LuauSelectivelyRetainDFGArena)
-LUAU_FASTFLAG(LuauTypeFunResultInAutocomplete)
 
 namespace Luau
 {
@@ -81,20 +82,6 @@ struct BuildQueueItem
     Frontend::Stats stats;
 };
 
-struct BuildQueueWorkState
-{
-    std::function<void(std::function<void()> task)> executeTask;
-
-    std::vector<BuildQueueItem> buildQueueItems;
-
-    std::mutex mtx;
-    std::condition_variable cv;
-    std::vector<size_t> readyQueueItems;
-
-    size_t processing = 0;
-    size_t remaining = 0;
-};
-
 std::optional<Mode> parseMode(const std::vector<HotComment>& hotcomments)
 {
     for (const HotComment& hc : hotcomments)
@@ -459,6 +446,20 @@ CheckResult Frontend::check(const ModuleName& name, std::optional<FrontendOption
 
         if (item.name == name)
             checkResult.lintResult = item.module->lintResult;
+
+        if (FFlag::StudioReportLuauAny2 && item.options.retainFullTypeGraphs)
+        {
+            if (item.module)
+            {
+                const SourceModule& sourceModule = *item.sourceModule;
+                if (sourceModule.mode == Luau::Mode::Strict)
+                {
+                    item.module->ats.root = toString(sourceModule.root);
+                }
+                item.module->ats.rootSrc = sourceModule.root;
+                item.module->ats.traverse(item.module.get(), sourceModule.root, NotNull{&builtinTypes_});
+            }
+        }
     }
 
     return checkResult;
@@ -480,203 +481,6 @@ std::vector<ModuleName> Frontend::checkQueuedModules(
     std::function<bool(size_t done, size_t total)> progress
 )
 {
-    if (!FFlag::LuauFixMultithreadTypecheck)
-    {
-        return checkQueuedModules_DEPRECATED(optionOverride, executeTask, progress);
-    }
-
-    FrontendOptions frontendOptions = optionOverride.value_or(options);
-    if (FFlag::LuauSolverV2)
-        frontendOptions.forAutocomplete = false;
-
-    // By taking data into locals, we make sure queue is cleared at the end, even if an ICE or a different exception is thrown
-    std::vector<ModuleName> currModuleQueue;
-    std::swap(currModuleQueue, moduleQueue);
-
-    DenseHashSet<Luau::ModuleName> seen{{}};
-
-    std::shared_ptr<BuildQueueWorkState> state = std::make_shared<BuildQueueWorkState>();
-
-    for (const ModuleName& name : currModuleQueue)
-    {
-        if (seen.contains(name))
-            continue;
-
-        if (!isDirty(name, frontendOptions.forAutocomplete))
-        {
-            seen.insert(name);
-            continue;
-        }
-
-        std::vector<ModuleName> queue;
-        bool cycleDetected = parseGraph(
-            queue,
-            name,
-            frontendOptions.forAutocomplete,
-            [&seen](const ModuleName& name)
-            {
-                return seen.contains(name);
-            }
-        );
-
-        addBuildQueueItems(state->buildQueueItems, queue, cycleDetected, seen, frontendOptions);
-    }
-
-    if (state->buildQueueItems.empty())
-        return {};
-
-    // We need a mapping from modules to build queue slots
-    std::unordered_map<ModuleName, size_t> moduleNameToQueue;
-
-    for (size_t i = 0; i < state->buildQueueItems.size(); i++)
-    {
-        BuildQueueItem& item = state->buildQueueItems[i];
-        moduleNameToQueue[item.name] = i;
-    }
-
-    // Default task execution is single-threaded and immediate
-    if (!executeTask)
-    {
-        executeTask = [](std::function<void()> task)
-        {
-            task();
-        };
-    }
-
-    state->executeTask = executeTask;
-    state->remaining = state->buildQueueItems.size();
-
-    // Record dependencies between modules
-    for (size_t i = 0; i < state->buildQueueItems.size(); i++)
-    {
-        BuildQueueItem& item = state->buildQueueItems[i];
-
-        for (const ModuleName& dep : item.sourceNode->requireSet)
-        {
-            if (auto it = sourceNodes.find(dep); it != sourceNodes.end())
-            {
-                if (it->second->hasDirtyModule(frontendOptions.forAutocomplete))
-                {
-                    item.dirtyDependencies++;
-
-                    state->buildQueueItems[moduleNameToQueue[dep]].reverseDeps.push_back(i);
-                }
-            }
-        }
-    }
-
-    // In the first pass, check all modules with no pending dependencies
-    for (size_t i = 0; i < state->buildQueueItems.size(); i++)
-    {
-        if (state->buildQueueItems[i].dirtyDependencies == 0)
-            sendQueueItemTask(state, i);
-    }
-
-    // If not a single item was found, a cycle in the graph was hit
-    if (state->processing == 0)
-        sendQueueCycleItemTask(state);
-
-    std::vector<size_t> nextItems;
-    std::optional<size_t> itemWithException;
-    bool cancelled = false;
-
-    while (state->remaining != 0)
-    {
-        {
-            std::unique_lock guard(state->mtx);
-
-            // If nothing is ready yet, wait
-            state->cv.wait(
-                guard,
-                [state]
-                {
-                    return !state->readyQueueItems.empty();
-                }
-            );
-
-            // Handle checked items
-            for (size_t i : state->readyQueueItems)
-            {
-                const BuildQueueItem& item = state->buildQueueItems[i];
-
-                // If exception was thrown, stop adding new items and wait for processing items to complete
-                if (item.exception)
-                    itemWithException = i;
-
-                if (item.module && item.module->cancelled)
-                    cancelled = true;
-
-                if (itemWithException || cancelled)
-                    break;
-
-                recordItemResult(item);
-
-                // Notify items that were waiting for this dependency
-                for (size_t reverseDep : item.reverseDeps)
-                {
-                    BuildQueueItem& reverseDepItem = state->buildQueueItems[reverseDep];
-
-                    LUAU_ASSERT(reverseDepItem.dirtyDependencies != 0);
-                    reverseDepItem.dirtyDependencies--;
-
-                    // In case of a module cycle earlier, check if unlocked an item that was already processed
-                    if (!reverseDepItem.processing && reverseDepItem.dirtyDependencies == 0)
-                        nextItems.push_back(reverseDep);
-                }
-            }
-
-            LUAU_ASSERT(state->processing >= state->readyQueueItems.size());
-            state->processing -= state->readyQueueItems.size();
-
-            LUAU_ASSERT(state->remaining >= state->readyQueueItems.size());
-            state->remaining -= state->readyQueueItems.size();
-            state->readyQueueItems.clear();
-        }
-
-        if (progress)
-        {
-            if (!progress(state->buildQueueItems.size() - state->remaining, state->buildQueueItems.size()))
-                cancelled = true;
-        }
-
-        // Items cannot be submitted while holding the lock
-        for (size_t i : nextItems)
-            sendQueueItemTask(state, i);
-        nextItems.clear();
-
-        if (state->processing == 0)
-        {
-            // Typechecking might have been cancelled by user, don't return partial results
-            if (cancelled)
-                return {};
-
-            // We might have stopped because of a pending exception
-            if (itemWithException)
-                recordItemResult(state->buildQueueItems[*itemWithException]);
-        }
-
-        // If we aren't done, but don't have anything processing, we hit a cycle
-        if (state->remaining != 0 && state->processing == 0)
-            sendQueueCycleItemTask(state);
-    }
-
-    std::vector<ModuleName> checkedModules;
-    checkedModules.reserve(state->buildQueueItems.size());
-
-    for (size_t i = 0; i < state->buildQueueItems.size(); i++)
-        checkedModules.push_back(std::move(state->buildQueueItems[i].name));
-
-    return checkedModules;
-}
-
-std::vector<ModuleName> Frontend::checkQueuedModules_DEPRECATED(
-    std::optional<FrontendOptions> optionOverride,
-    std::function<void(std::function<void()> task)> executeTask,
-    std::function<bool(size_t done, size_t total)> progress
-)
-{
-    LUAU_ASSERT(!FFlag::LuauFixMultithreadTypecheck);
-
     FrontendOptions frontendOptions = optionOverride.value_or(options);
     if (FFlag::LuauSolverV2)
         frontendOptions.forAutocomplete = false;
@@ -1018,11 +822,14 @@ bool Frontend::parseGraph(
 
             buildQueue.push_back(top->name);
 
-            // at this point we know all valid dependencies are processed into SourceNodes
-            for (const ModuleName& dep : top->requireSet)
+            if (FFlag::LuauBetterReverseDependencyTracking)
             {
-                if (auto it = sourceNodes.find(dep); it != sourceNodes.end())
-                    it->second->dependents.insert(top->name);
+                // at this point we know all valid dependencies are processed into SourceNodes
+                for (const ModuleName& dep : top->requireSet)
+                {
+                    if (auto it = sourceNodes.find(dep); it != sourceNodes.end())
+                        it->second->dependents.insert(top->name);
+                }
             }
         }
         else
@@ -1311,35 +1118,51 @@ void Frontend::recordItemResult(const BuildQueueItem& item)
     if (item.exception)
         std::rethrow_exception(item.exception);
 
-    bool replacedModule = false;
-    if (item.options.forAutocomplete)
+    if (FFlag::LuauBetterReverseDependencyTracking)
     {
-        replacedModule = moduleResolverForAutocomplete.setModule(item.name, item.module);
-        item.sourceNode->dirtyModuleForAutocomplete = false;
+        bool replacedModule = false;
+        if (item.options.forAutocomplete)
+        {
+            replacedModule = moduleResolverForAutocomplete.setModule(item.name, item.module);
+            item.sourceNode->dirtyModuleForAutocomplete = false;
+        }
+        else
+        {
+            replacedModule = moduleResolver.setModule(item.name, item.module);
+            item.sourceNode->dirtyModule = false;
+        }
+
+        if (replacedModule)
+        {
+            LUAU_TIMETRACE_SCOPE("Frontend::invalidateDependentModules", "Frontend");
+            LUAU_TIMETRACE_ARGUMENT("name", item.name.c_str());
+            traverseDependents(
+                item.name,
+                [forAutocomplete = item.options.forAutocomplete](SourceNode& sourceNode)
+                {
+                    bool traverseSubtree = !sourceNode.hasInvalidModuleDependency(forAutocomplete);
+                    sourceNode.setInvalidModuleDependency(true, forAutocomplete);
+                    return traverseSubtree;
+                }
+            );
+        }
+
+        item.sourceNode->setInvalidModuleDependency(false, item.options.forAutocomplete);
     }
     else
     {
-        replacedModule = moduleResolver.setModule(item.name, item.module);
-        item.sourceNode->dirtyModule = false;
+        if (item.options.forAutocomplete)
+        {
+            moduleResolverForAutocomplete.setModule(item.name, item.module);
+            item.sourceNode->dirtyModuleForAutocomplete = false;
+        }
+        else
+        {
+            moduleResolver.setModule(item.name, item.module);
+            item.sourceNode->dirtyModule = false;
+        }
     }
 
-    if (replacedModule)
-    {
-        LUAU_TIMETRACE_SCOPE("Frontend::invalidateDependentModules", "Frontend");
-        LUAU_TIMETRACE_ARGUMENT("name", item.name.c_str());
-        traverseDependents(
-            item.name,
-            [forAutocomplete = item.options.forAutocomplete](SourceNode& sourceNode)
-            {
-                bool traverseSubtree = !sourceNode.hasInvalidModuleDependency(forAutocomplete);
-                sourceNode.setInvalidModuleDependency(true, forAutocomplete);
-                return traverseSubtree;
-            }
-        );
-    }
-
-    item.sourceNode->setInvalidModuleDependency(false, item.options.forAutocomplete);
-
     stats.timeCheck += item.stats.timeCheck;
     stats.timeLint += item.stats.timeLint;
 
@@ -1347,58 +1170,6 @@ void Frontend::recordItemResult(const BuildQueueItem& item)
     stats.filesNonstrict += item.stats.filesNonstrict;
 }
 
-void Frontend::performQueueItemTask(std::shared_ptr<BuildQueueWorkState> state, size_t itemPos)
-{
-    BuildQueueItem& item = state->buildQueueItems[itemPos];
-
-    try
-    {
-        checkBuildQueueItem(item);
-    }
-    catch (...)
-    {
-        item.exception = std::current_exception();
-    }
-
-    {
-        std::unique_lock guard(state->mtx);
-        state->readyQueueItems.push_back(itemPos);
-    }
-
-    state->cv.notify_one();
-}
-
-void Frontend::sendQueueItemTask(std::shared_ptr<BuildQueueWorkState> state, size_t itemPos)
-{
-    BuildQueueItem& item = state->buildQueueItems[itemPos];
-
-    LUAU_ASSERT(!item.processing);
-    item.processing = true;
-
-    state->processing++;
-
-    state->executeTask(
-        [this, state, itemPos]()
-        {
-            performQueueItemTask(state, itemPos);
-        }
-    );
-}
-
-void Frontend::sendQueueCycleItemTask(std::shared_ptr<BuildQueueWorkState> state)
-{
-    for (size_t i = 0; i < state->buildQueueItems.size(); i++)
-    {
-        BuildQueueItem& item = state->buildQueueItems[i];
-
-        if (!item.processing)
-        {
-            sendQueueItemTask(state, i);
-            break;
-        }
-    }
-}
-
 ScopePtr Frontend::getModuleEnvironment(const SourceModule& module, const Config& config, bool forAutocomplete) const
 {
     ScopePtr result;
@@ -1428,6 +1199,7 @@ ScopePtr Frontend::getModuleEnvironment(const SourceModule& module, const Config
 
 bool Frontend::allModuleDependenciesValid(const ModuleName& name, bool forAutocomplete) const
 {
+    LUAU_ASSERT(FFlag::LuauBetterReverseDependencyTracking);
     auto it = sourceNodes.find(name);
     return it != sourceNodes.end() && !it->second->hasInvalidModuleDependency(forAutocomplete);
 }
@@ -1449,27 +1221,72 @@ void Frontend::markDirty(const ModuleName& name, std::vector<ModuleName>* marked
     LUAU_TIMETRACE_SCOPE("Frontend::markDirty", "Frontend");
     LUAU_TIMETRACE_ARGUMENT("name", name.c_str());
 
-    traverseDependents(
-        name,
-        [markedDirty](SourceNode& sourceNode)
+    if (FFlag::LuauBetterReverseDependencyTracking)
+    {
+        traverseDependents(
+            name,
+            [markedDirty](SourceNode& sourceNode)
+            {
+                if (markedDirty)
+                    markedDirty->push_back(sourceNode.name);
+
+                if (sourceNode.dirtySourceModule && sourceNode.dirtyModule && sourceNode.dirtyModuleForAutocomplete)
+                    return false;
+
+                sourceNode.dirtySourceModule = true;
+                sourceNode.dirtyModule = true;
+                sourceNode.dirtyModuleForAutocomplete = true;
+
+                return true;
+            }
+        );
+    }
+    else
+    {
+        if (sourceNodes.count(name) == 0)
+            return;
+
+        std::unordered_map<ModuleName, std::vector<ModuleName>> reverseDeps;
+        for (const auto& module : sourceNodes)
         {
+            for (const auto& dep : module.second->requireSet)
+                reverseDeps[dep].push_back(module.first);
+        }
+
+        std::vector<ModuleName> queue{name};
+
+        while (!queue.empty())
+        {
+            ModuleName next = std::move(queue.back());
+            queue.pop_back();
+
+            LUAU_ASSERT(sourceNodes.count(next) > 0);
+            SourceNode& sourceNode = *sourceNodes[next];
+
             if (markedDirty)
-                markedDirty->push_back(sourceNode.name);
+                markedDirty->push_back(next);
 
             if (sourceNode.dirtySourceModule && sourceNode.dirtyModule && sourceNode.dirtyModuleForAutocomplete)
-                return false;
+                continue;
 
             sourceNode.dirtySourceModule = true;
             sourceNode.dirtyModule = true;
             sourceNode.dirtyModuleForAutocomplete = true;
 
-            return true;
+            if (0 == reverseDeps.count(next))
+                continue;
+
+            sourceModules.erase(next);
+
+            const std::vector<ModuleName>& dependents = reverseDeps[next];
+            queue.insert(queue.end(), dependents.begin(), dependents.end());
         }
-    );
+    }
 }
 
 void Frontend::traverseDependents(const ModuleName& name, std::function<bool(SourceNode&)> processSubtree)
 {
+    LUAU_ASSERT(FFlag::LuauBetterReverseDependencyTracking);
     LUAU_TIMETRACE_SCOPE("Frontend::traverseDependents", "Frontend");
 
     if (sourceNodes.count(name) == 0)
@@ -1516,7 +1333,6 @@ ModulePtr check(
     NotNull<ModuleResolver> moduleResolver,
     NotNull<FileResolver> fileResolver,
     const ScopePtr& parentScope,
-    const ScopePtr& typeFunctionScope,
     std::function<void(const ModuleName&, const ScopePtr&)> prepareModuleScope,
     FrontendOptions options,
     TypeCheckLimits limits,
@@ -1533,7 +1349,6 @@ ModulePtr check(
         moduleResolver,
         fileResolver,
         parentScope,
-        typeFunctionScope,
         std::move(prepareModuleScope),
         options,
         limits,
@@ -1595,7 +1410,6 @@ ModulePtr check(
     NotNull<ModuleResolver> moduleResolver,
     NotNull<FileResolver> fileResolver,
     const ScopePtr& parentScope,
-    const ScopePtr& typeFunctionScope,
     std::function<void(const ModuleName&, const ScopePtr&)> prepareModuleScope,
     FrontendOptions options,
     TypeCheckLimits limits,
@@ -1608,7 +1422,8 @@ ModulePtr check(
     LUAU_TIMETRACE_ARGUMENT("name", sourceModule.humanReadableName.c_str());
 
     ModulePtr result = std::make_shared<Module>();
-    result->checkedInNewSolver = true;
+    if (FFlag::LuauStoreSolverTypeOnModule)
+        result->checkedInNewSolver = true;
     result->name = sourceModule.name;
     result->humanReadableName = sourceModule.humanReadableName;
     result->mode = mode;
@@ -1616,8 +1431,6 @@ ModulePtr check(
     result->interfaceTypes.owningModule = result.get();
     result->allocator = sourceModule.allocator;
     result->names = sourceModule.names;
-    if (FFlag::LuauModuleHoldsAstRoot)
-        result->root = sourceModule.root;
 
     iceHandler->moduleName = sourceModule.name;
 
@@ -1642,7 +1455,7 @@ ModulePtr check(
     SimplifierPtr simplifier = newSimplifier(NotNull{&result->internalTypes}, builtinTypes);
     TypeFunctionRuntime typeFunctionRuntime{iceHandler, NotNull{&limits}};
 
-    typeFunctionRuntime.allowEvaluation = FFlag::LuauTypeFunResultInAutocomplete || sourceModule.parseErrors.empty();
+    typeFunctionRuntime.allowEvaluation = sourceModule.parseErrors.empty();
 
     ConstraintGenerator cg{
         result,
@@ -1653,7 +1466,6 @@ ModulePtr check(
         builtinTypes,
         iceHandler,
         parentScope,
-        typeFunctionScope,
         std::move(prepareModuleScope),
         logger.get(),
         NotNull{&dfg},
@@ -1669,7 +1481,6 @@ ModulePtr check(
         NotNull{&typeFunctionRuntime},
         NotNull(cg.rootScope),
         borrowConstraints(cg.constraints),
-        NotNull{&cg.scopeToFunction},
         result->name,
         moduleResolver,
         requireCycles,
@@ -1836,7 +1647,6 @@ ModulePtr Frontend::check(
                 NotNull{forAutocomplete ? &moduleResolverForAutocomplete : &moduleResolver},
                 NotNull{fileResolver},
                 environmentScope ? *environmentScope : globals.globalScope,
-                globals.globalTypeFunctionScope,
                 prepareModuleScopeWrap,
                 options,
                 typeCheckLimits,
@@ -1935,11 +1745,14 @@ std::pair<SourceNode*, SourceModule*> Frontend::getSourceNode(const ModuleName&
     sourceNode->name = sourceModule->name;
     sourceNode->humanReadableName = sourceModule->humanReadableName;
 
-    // clear all prior dependents. we will re-add them after parsing the rest of the graph
-    for (const auto& [moduleName, _] : sourceNode->requireLocations)
+    if (FFlag::LuauBetterReverseDependencyTracking)
     {
-        if (auto depIt = sourceNodes.find(moduleName); depIt != sourceNodes.end())
-            depIt->second->dependents.erase(sourceNode->name);
+        // clear all prior dependents. we will re-add them after parsing the rest of the graph
+        for (const auto& [moduleName, _] : sourceNode->requireLocations)
+        {
+            if (auto depIt = sourceNodes.find(moduleName); depIt != sourceNodes.end())
+                depIt->second->dependents.erase(sourceNode->name);
+        }
     }
 
     sourceNode->requireSet.clear();
@@ -2067,9 +1880,17 @@ bool FrontendModuleResolver::setModule(const ModuleName& moduleName, ModulePtr m
 {
     std::scoped_lock lock(moduleMutex);
 
-    bool replaced = modules.count(moduleName) > 0;
-    modules[moduleName] = std::move(module);
-    return replaced;
+    if (FFlag::LuauBetterReverseDependencyTracking)
+    {
+        bool replaced = modules.count(moduleName) > 0;
+        modules[moduleName] = std::move(module);
+        return replaced;
+    }
+    else
+    {
+        modules[moduleName] = std::move(module);
+        return false;
+    }
 }
 
 void FrontendModuleResolver::clearModules()

Analysis/src/Generalization.cpp

@@ -30,6 +30,7 @@ struct MutatingGeneralizer : TypeOnceVisitor
     std::vector<TypePackId> genericPacks;
 
     bool isWithinFunction = false;
+    bool avoidSealingTables = false;
 
     MutatingGeneralizer(
         NotNull<TypeArena> arena,
@@ -37,7 +38,8 @@ struct MutatingGeneralizer : TypeOnceVisitor
         NotNull<Scope> scope,
         NotNull<DenseHashSet<TypeId>> cachedTypes,
         DenseHashMap<const void*, size_t> positiveTypes,
-        DenseHashMap<const void*, size_t> negativeTypes
+        DenseHashMap<const void*, size_t> negativeTypes,
+        bool avoidSealingTables
     )
         : TypeOnceVisitor(/* skipBoundTypes */ true)
         , arena(arena)
@@ -46,6 +48,7 @@ struct MutatingGeneralizer : TypeOnceVisitor
         , cachedTypes(cachedTypes)
         , positiveTypes(std::move(positiveTypes))
         , negativeTypes(std::move(negativeTypes))
+        , avoidSealingTables(avoidSealingTables)
     {
     }
 
@@ -142,7 +145,7 @@ struct MutatingGeneralizer : TypeOnceVisitor
                 TypeId onlyType = it->parts[0];
                 LUAU_ASSERT(onlyType != needle);
                 emplaceType<BoundType>(asMutable(needle), onlyType);
-            }
+            } 
             else if (FFlag::LuauGeneralizationRemoveRecursiveUpperBound2 && it->parts.empty())
             {
                 emplaceType<BoundType>(asMutable(needle), builtinTypes->unknownType);
@@ -289,7 +292,8 @@ struct MutatingGeneralizer : TypeOnceVisitor
         TableType* tt = getMutable<TableType>(ty);
         LUAU_ASSERT(tt);
 
-        tt->state = TableState::Sealed;
+        if (!avoidSealingTables)
+            tt->state = TableState::Sealed;
 
         return true;
     }
@@ -328,19 +332,26 @@ struct FreeTypeSearcher : TypeVisitor
     {
     }
 
-    Polarity polarity = Polarity::Positive;
+    enum Polarity
+    {
+        Positive,
+        Negative,
+        Both,
+    };
+
+    Polarity polarity = Positive;
 
     void flip()
     {
         switch (polarity)
         {
-        case Polarity::Positive:
-            polarity = Polarity::Negative;
+        case Positive:
+            polarity = Negative;
             break;
-        case Polarity::Negative:
-            polarity = Polarity::Positive;
+        case Negative:
+            polarity = Positive;
             break;
-        default:
+        case Both:
             break;
         }
     }
@@ -348,11 +359,11 @@ struct FreeTypeSearcher : TypeVisitor
     DenseHashSet<const void*> seenPositive{nullptr};
     DenseHashSet<const void*> seenNegative{nullptr};
 
-    bool seenWithCurrentPolarity(const void* ty)
+    bool seenWithPolarity(const void* ty)
     {
         switch (polarity)
         {
-        case Polarity::Positive:
+        case Positive:
         {
             if (seenPositive.contains(ty))
                 return true;
@@ -360,7 +371,7 @@ struct FreeTypeSearcher : TypeVisitor
             seenPositive.insert(ty);
             return false;
         }
-        case Polarity::Negative:
+        case Negative:
         {
             if (seenNegative.contains(ty))
                 return true;
@@ -368,7 +379,7 @@ struct FreeTypeSearcher : TypeVisitor
             seenNegative.insert(ty);
             return false;
         }
-        case Polarity::Mixed:
+        case Both:
         {
             if (seenPositive.contains(ty) && seenNegative.contains(ty))
                 return true;
@@ -377,8 +388,6 @@ struct FreeTypeSearcher : TypeVisitor
             seenNegative.insert(ty);
             return false;
         }
-        default:
-            LUAU_ASSERT(!"Unreachable");
         }
 
         return false;
@@ -392,7 +401,7 @@ struct FreeTypeSearcher : TypeVisitor
 
     bool visit(TypeId ty) override
     {
-        if (cachedTypes->contains(ty) || seenWithCurrentPolarity(ty))
+        if (cachedTypes->contains(ty) || seenWithPolarity(ty))
             return false;
 
         LUAU_ASSERT(ty);
@@ -401,7 +410,7 @@ struct FreeTypeSearcher : TypeVisitor
 
     bool visit(TypeId ty, const FreeType& ft) override
     {
-        if (cachedTypes->contains(ty) || seenWithCurrentPolarity(ty))
+        if (cachedTypes->contains(ty) || seenWithPolarity(ty))
             return false;
 
         if (!subsumes(scope, ft.scope))
@@ -409,18 +418,16 @@ struct FreeTypeSearcher : TypeVisitor
 
         switch (polarity)
         {
-        case Polarity::Positive:
+        case Positive:
             positiveTypes[ty]++;
             break;
-        case Polarity::Negative:
+        case Negative:
             negativeTypes[ty]++;
             break;
-        case Polarity::Mixed:
+        case Both:
             positiveTypes[ty]++;
             negativeTypes[ty]++;
             break;
-        default:
-            LUAU_ASSERT(!"Unreachable");
         }
 
         return true;
@@ -428,25 +435,23 @@ struct FreeTypeSearcher : TypeVisitor
 
     bool visit(TypeId ty, const TableType& tt) override
     {
-        if (cachedTypes->contains(ty) || seenWithCurrentPolarity(ty))
+        if (cachedTypes->contains(ty) || seenWithPolarity(ty))
             return false;
 
         if ((tt.state == TableState::Free || tt.state == TableState::Unsealed) && subsumes(scope, tt.scope))
         {
             switch (polarity)
             {
-            case Polarity::Positive:
+            case Positive:
                 positiveTypes[ty]++;
                 break;
-            case Polarity::Negative:
+            case Negative:
                 negativeTypes[ty]++;
                 break;
-            case Polarity::Mixed:
+            case Both:
                 positiveTypes[ty]++;
                 negativeTypes[ty]++;
                 break;
-            default:
-                LUAU_ASSERT(!"Unreachable");
             }
         }
 
@@ -459,7 +464,7 @@ struct FreeTypeSearcher : TypeVisitor
                 LUAU_ASSERT(prop.isShared() || FFlag::LuauAutocompleteRefactorsForIncrementalAutocomplete);
 
                 Polarity p = polarity;
-                polarity = Polarity::Mixed;
+                polarity = Both;
                 traverse(prop.type());
                 polarity = p;
             }
@@ -476,7 +481,7 @@ struct FreeTypeSearcher : TypeVisitor
 
     bool visit(TypeId ty, const FunctionType& ft) override
     {
-        if (cachedTypes->contains(ty) || seenWithCurrentPolarity(ty))
+        if (cachedTypes->contains(ty) || seenWithPolarity(ty))
             return false;
 
         flip();
@@ -495,7 +500,7 @@ struct FreeTypeSearcher : TypeVisitor
 
     bool visit(TypePackId tp, const FreeTypePack& ftp) override
     {
-        if (seenWithCurrentPolarity(tp))
+        if (seenWithPolarity(tp))
             return false;
 
         if (!subsumes(scope, ftp.scope))
@@ -503,18 +508,16 @@ struct FreeTypeSearcher : TypeVisitor
 
         switch (polarity)
         {
-        case Polarity::Positive:
+        case Positive:
             positiveTypes[tp]++;
             break;
-        case Polarity::Negative:
+        case Negative:
             negativeTypes[tp]++;
             break;
-        case Polarity::Mixed:
+        case Both:
             positiveTypes[tp]++;
             negativeTypes[tp]++;
             break;
-        default:
-            LUAU_ASSERT(!"Unreachable");
         }
 
         return true;
@@ -544,7 +547,7 @@ struct TypeCacher : TypeOnceVisitor
     {
     }
 
-    void cache(TypeId ty) const
+    void cache(TypeId ty)
     {
         cachedTypes->insert(ty);
     }
@@ -969,7 +972,8 @@ std::optional<TypeId> generalize(
     NotNull<BuiltinTypes> builtinTypes,
     NotNull<Scope> scope,
     NotNull<DenseHashSet<TypeId>> cachedTypes,
-    TypeId ty
+    TypeId ty,
+    bool avoidSealingTables
 )
 {
     ty = follow(ty);
@@ -980,7 +984,7 @@ std::optional<TypeId> generalize(
     FreeTypeSearcher fts{scope, cachedTypes};
     fts.traverse(ty);
 
-    MutatingGeneralizer gen{arena, builtinTypes, scope, cachedTypes, std::move(fts.positiveTypes), std::move(fts.negativeTypes)};
+    MutatingGeneralizer gen{arena, builtinTypes, scope, cachedTypes, std::move(fts.positiveTypes), std::move(fts.negativeTypes), avoidSealingTables};
 
     gen.traverse(ty);
 

Analysis/src/GlobalTypes.cpp

@@ -9,7 +9,6 @@ GlobalTypes::GlobalTypes(NotNull<BuiltinTypes> builtinTypes)
     : builtinTypes(builtinTypes)
 {
     globalScope = std::make_shared<Scope>(globalTypes.addTypePack(TypePackVar{FreeTypePack{TypeLevel{}}}));
-    globalTypeFunctionScope = std::make_shared<Scope>(globalTypes.addTypePack(TypePackVar{FreeTypePack{TypeLevel{}}}));
 
     globalScope->addBuiltinTypeBinding("any", TypeFun{{}, builtinTypes->anyType});
     globalScope->addBuiltinTypeBinding("nil", TypeFun{{}, builtinTypes->nilType});

Analysis/src/Linter.cpp

@@ -19,8 +19,6 @@ LUAU_FASTFLAG(LuauSolverV2)
 LUAU_FASTFLAG(LuauAttribute)
 LUAU_FASTFLAGVARIABLE(LintRedundantNativeAttribute)
 
-LUAU_FASTFLAG(LuauDeprecatedAttribute)
-
 namespace Luau
 {
 
@@ -2282,57 +2280,6 @@ private:
     {
     }
 
-    bool visit(AstExprLocal* node) override
-    {
-        if (FFlag::LuauDeprecatedAttribute)
-        {
-
-            const FunctionType* fty = getFunctionType(node);
-            bool shouldReport = fty && fty->isDeprecatedFunction && !inScope(fty);
-
-            if (shouldReport)
-                report(node->location, node->local->name.value);
-        }
-
-        return true;
-    }
-
-    bool visit(AstExprGlobal* node) override
-    {
-        if (FFlag::LuauDeprecatedAttribute)
-        {
-            const FunctionType* fty = getFunctionType(node);
-            bool shouldReport = fty && fty->isDeprecatedFunction && !inScope(fty);
-
-            if (shouldReport)
-                report(node->location, node->name.value);
-        }
-
-        return true;
-    }
-
-    bool visit(AstStatLocalFunction* node) override
-    {
-        if (FFlag::LuauDeprecatedAttribute)
-        {
-            check(node->func);
-            return false;
-        }
-        else
-            return true;
-    }
-
-    bool visit(AstStatFunction* node) override
-    {
-        if (FFlag::LuauDeprecatedAttribute)
-        {
-            check(node->func);
-            return false;
-        }
-        else
-            return true;
-    }
-
     bool visit(AstExprIndexName* node) override
     {
         if (std::optional<TypeId> ty = context->getType(node->expr))
@@ -2378,59 +2325,18 @@ private:
 
             if (prop && prop->deprecated)
                 report(node->location, *prop, cty->name.c_str(), node->index.value);
-            else if (FFlag::LuauDeprecatedAttribute && prop)
-            {
-                if (std::optional<TypeId> ty = prop->readTy)
-                {
-                    const FunctionType* fty = get<FunctionType>(follow(ty));
-                    bool shouldReport = fty && fty->isDeprecatedFunction && !inScope(fty);
-
-                    if (shouldReport)
-                    {
-                        const char* className = nullptr;
-                        if (AstExprGlobal* global = node->expr->as<AstExprGlobal>())
-                            className = global->name.value;
-
-                        const char* functionName = node->index.value;
-
-                        report(node->location, className, functionName);
-                    }
-                }
-            }
         }
         else if (const TableType* tty = get<TableType>(ty))
         {
             auto prop = tty->props.find(node->index.value);
 
-            if (prop != tty->props.end())
+            if (prop != tty->props.end() && prop->second.deprecated)
             {
-                if (prop->second.deprecated)
-                {
-                    // strip synthetic typeof() for builtin tables
-                    if (tty->name && tty->name->compare(0, 7, "typeof(") == 0 && tty->name->back() == ')')
-                        report(node->location, prop->second, tty->name->substr(7, tty->name->length() - 8).c_str(), node->index.value);
-                    else
-                        report(node->location, prop->second, tty->name ? tty->name->c_str() : nullptr, node->index.value);
-                }
-                else if (FFlag::LuauDeprecatedAttribute)
-                {
-                    if (std::optional<TypeId> ty = prop->second.readTy)
-                    {
-                        const FunctionType* fty = get<FunctionType>(follow(ty));
-                        bool shouldReport = fty && fty->isDeprecatedFunction && !inScope(fty);
-
-                        if (shouldReport)
-                        {
-                            const char* className = nullptr;
-                            if (AstExprGlobal* global = node->expr->as<AstExprGlobal>())
-                                className = global->name.value;
-
-                            const char* functionName = node->index.value;
-
-                            report(node->location, className, functionName);
-                        }
-                    }
-                }
+                // strip synthetic typeof() for builtin tables
+                if (tty->name && tty->name->compare(0, 7, "typeof(") == 0 && tty->name->back() == ')')
+                    report(node->location, prop->second, tty->name->substr(7, tty->name->length() - 8).c_str(), node->index.value);
+                else
+                    report(node->location, prop->second, tty->name ? tty->name->c_str() : nullptr, node->index.value);
             }
         }
     }
@@ -2449,26 +2355,6 @@ private:
         }
     }
 
-    void check(AstExprFunction* func)
-    {
-        LUAU_ASSERT(FFlag::LuauDeprecatedAttribute);
-        LUAU_ASSERT(func);
-
-        const FunctionType* fty = getFunctionType(func);
-        bool isDeprecated = fty && fty->isDeprecatedFunction;
-
-        // If a function is deprecated, we don't want to flag its recursive uses.
-        // So we push it on a stack while its body is being analyzed.
-        // When a deprecated function is used, we check the stack to ensure that we are not inside that function.
-        if (isDeprecated)
-            pushScope(fty);
-
-        func->visit(this);
-
-        if (isDeprecated)
-            popScope(fty);
-    }
-
     void report(const Location& location, const Property& prop, const char* container, const char* field)
     {
         std::string suggestion = prop.deprecatedSuggestion.empty() ? "" : format(", use '%s' instead", prop.deprecatedSuggestion.c_str());
@@ -2478,63 +2364,6 @@ private:
         else
             emitWarning(*context, LintWarning::Code_DeprecatedApi, location, "Member '%s' is deprecated%s", field, suggestion.c_str());
     }
-
-    void report(const Location& location, const char* tableName, const char* functionName)
-    {
-        LUAU_ASSERT(FFlag::LuauDeprecatedAttribute);
-
-        if (tableName)
-            emitWarning(*context, LintWarning::Code_DeprecatedApi, location, "Member '%s.%s' is deprecated", tableName, functionName);
-        else
-            emitWarning(*context, LintWarning::Code_DeprecatedApi, location, "Member '%s' is deprecated", functionName);
-    }
-
-    void report(const Location& location, const char* functionName)
-    {
-        LUAU_ASSERT(FFlag::LuauDeprecatedAttribute);
-
-        emitWarning(*context, LintWarning::Code_DeprecatedApi, location, "Function '%s' is deprecated", functionName);
-    }
-
-    std::vector<const FunctionType*> functionTypeScopeStack;
-
-    void pushScope(const FunctionType* fty)
-    {
-        LUAU_ASSERT(FFlag::LuauDeprecatedAttribute);
-        LUAU_ASSERT(fty);
-
-        functionTypeScopeStack.push_back(fty);
-    }
-
-    void popScope(const FunctionType* fty)
-    {
-        LUAU_ASSERT(FFlag::LuauDeprecatedAttribute);
-        LUAU_ASSERT(fty);
-
-        LUAU_ASSERT(fty == functionTypeScopeStack.back());
-        functionTypeScopeStack.pop_back();
-    }
-
-    bool inScope(const FunctionType* fty) const
-    {
-        LUAU_ASSERT(FFlag::LuauDeprecatedAttribute);
-        LUAU_ASSERT(fty);
-
-        return std::find(functionTypeScopeStack.begin(), functionTypeScopeStack.end(), fty) != functionTypeScopeStack.end();
-    }
-
-    const FunctionType* getFunctionType(AstExpr* node)
-    {
-        LUAU_ASSERT(FFlag::LuauDeprecatedAttribute);
-
-        std::optional<TypeId> ty = context->getType(node);
-        if (!ty)
-            return nullptr;
-
-        const FunctionType* fty = get<FunctionType>(follow(ty));
-
-        return fty;
-    }
 };
 
 class LintTableOperations : AstVisitor

Analysis/src/Module.cpp

@@ -20,7 +20,7 @@ LUAU_FASTFLAGVARIABLE(LuauIncrementalAutocompleteCommentDetection)
 namespace Luau
 {
 
-static void defaultLogLuau(std::string_view context, std::string_view input)
+static void defaultLogLuau(std::string_view input)
 {
     // The default is to do nothing because we don't want to mess with
     // the xml parsing done by the dcr script.

Analysis/src/NonStrictTypeChecker.cpp

@@ -2,7 +2,6 @@
 #include "Luau/NonStrictTypeChecker.h"
 
 #include "Luau/Ast.h"
-#include "Luau/AstQuery.h"
 #include "Luau/Common.h"
 #include "Luau/Simplify.h"
 #include "Luau/Type.h"
@@ -20,10 +19,10 @@
 #include <iostream>
 #include <iterator>
 
+LUAU_FASTFLAGVARIABLE(LuauCountSelfCallsNonstrict)
 LUAU_FASTFLAG(LuauFreeTypesMustHaveBounds)
 LUAU_FASTFLAGVARIABLE(LuauNonStrictVisitorImprovements)
 LUAU_FASTFLAGVARIABLE(LuauNewNonStrictWarnOnUnknownGlobals)
-LUAU_FASTFLAGVARIABLE(LuauNonStrictFuncDefErrorFix)
 
 namespace Luau
 {
@@ -629,6 +628,17 @@ struct NonStrictTypeChecker
 
     NonStrictContext visit(AstExprCall* call)
     {
+        if (FFlag::LuauCountSelfCallsNonstrict)
+            return visitCall(call);
+        else
+            return visitCall_DEPRECATED(call);
+    }
+
+    // rename this to `visit` when `FFlag::LuauCountSelfCallsNonstrict` is removed, and clean up above `visit`.
+    NonStrictContext visitCall(AstExprCall* call)
+    {
+        LUAU_ASSERT(FFlag::LuauCountSelfCallsNonstrict);
+
         NonStrictContext fresh{};
         TypeId* originalCallTy = module->astOriginalCallTypes.find(call->func);
         if (!originalCallTy)
@@ -737,6 +747,109 @@ struct NonStrictTypeChecker
         return fresh;
     }
 
+    // Remove with `FFlag::LuauCountSelfCallsNonstrict` clean up.
+    NonStrictContext visitCall_DEPRECATED(AstExprCall* call)
+    {
+        LUAU_ASSERT(!FFlag::LuauCountSelfCallsNonstrict);
+
+        NonStrictContext fresh{};
+        TypeId* originalCallTy = module->astOriginalCallTypes.find(call->func);
+        if (!originalCallTy)
+            return fresh;
+
+        TypeId fnTy = *originalCallTy;
+        if (auto fn = get<FunctionType>(follow(fnTy)))
+        {
+            if (fn->isCheckedFunction)
+            {
+                // We know fn is a checked function, which means it looks like:
+                // (S1, ... SN) -> T &
+                // (~S1, unknown^N-1) -> error &
+                // (unknown, ~S2, unknown^N-2) -> error
+                // ...
+                // ...
+                // (unknown^N-1, ~S_N) -> error
+                std::vector<TypeId> argTypes;
+                argTypes.reserve(call->args.size);
+                // Pad out the arg types array with the types you would expect to see
+                TypePackIterator curr = begin(fn->argTypes);
+                TypePackIterator fin = end(fn->argTypes);
+                while (curr != fin)
+                {
+                    argTypes.push_back(*curr);
+                    ++curr;
+                }
+                if (auto argTail = curr.tail())
+                {
+                    if (const VariadicTypePack* vtp = get<VariadicTypePack>(follow(*argTail)))
+                    {
+                        while (argTypes.size() < call->args.size)
+                        {
+                            argTypes.push_back(vtp->ty);
+                        }
+                    }
+                }
+
+                std::string functionName = getFunctionNameAsString(*call->func).value_or("");
+                if (call->args.size > argTypes.size())
+                {
+                    // We are passing more arguments than we expect, so we should error
+                    reportError(CheckedFunctionIncorrectArgs{functionName, argTypes.size(), call->args.size}, call->location);
+                    return fresh;
+                }
+
+                for (size_t i = 0; i < call->args.size; i++)
+                {
+                    // For example, if the arg is "hi"
+                    // The actual arg type is string
+                    // The expected arg type is number
+                    // The type of the argument in the overload is ~number
+                    // We will compare arg and ~number
+                    AstExpr* arg = call->args.data[i];
+                    TypeId expectedArgType = argTypes[i];
+                    std::shared_ptr<const NormalizedType> norm = normalizer.normalize(expectedArgType);
+                    DefId def = dfg->getDef(arg);
+                    TypeId runTimeErrorTy;
+                    // If we're dealing with any, negating any will cause all subtype tests to fail
+                    // However, when someone calls this function, they're going to want to be able to pass it anything,
+                    // for that reason, we manually inject never into the context so that the runtime test will always pass.
+                    if (!norm)
+                        reportError(NormalizationTooComplex{}, arg->location);
+
+                    if (norm && get<AnyType>(norm->tops))
+                        runTimeErrorTy = builtinTypes->neverType;
+                    else
+                        runTimeErrorTy = getOrCreateNegation(expectedArgType);
+                    fresh.addContext(def, runTimeErrorTy);
+                }
+
+                // Populate the context and now iterate through each of the arguments to the call to find out if we satisfy the types
+                for (size_t i = 0; i < call->args.size; i++)
+                {
+                    AstExpr* arg = call->args.data[i];
+                    if (auto runTimeFailureType = willRunTimeError(arg, fresh))
+                        reportError(CheckedFunctionCallError{argTypes[i], *runTimeFailureType, functionName, i}, arg->location);
+                }
+
+                if (call->args.size < argTypes.size())
+                {
+                    // We are passing fewer arguments than we expect
+                    // so we need to ensure that the rest of the args are optional.
+                    bool remainingArgsOptional = true;
+                    for (size_t i = call->args.size; i < argTypes.size(); i++)
+                        remainingArgsOptional = remainingArgsOptional && isOptional(argTypes[i]);
+                    if (!remainingArgsOptional)
+                    {
+                        reportError(CheckedFunctionIncorrectArgs{functionName, argTypes.size(), call->args.size}, call->location);
+                        return fresh;
+                    }
+                }
+            }
+        }
+
+        return fresh;
+    }
+
     NonStrictContext visit(AstExprIndexName* indexName, ValueContext context)
     {
         if (FFlag::LuauNonStrictVisitorImprovements)
@@ -765,17 +878,7 @@ struct NonStrictTypeChecker
         for (AstLocal* local : exprFn->args)
         {
             if (std::optional<TypeId> ty = willRunTimeErrorFunctionDefinition(local, remainder))
-            {
-                if (FFlag::LuauNonStrictFuncDefErrorFix)
-                {
-                    const char* debugname = exprFn->debugname.value;
-                    reportError(NonStrictFunctionDefinitionError{debugname ? debugname : "", local->name.value, *ty}, local->location);
-                }
-                else
-                {
-                    reportError(NonStrictFunctionDefinitionError{exprFn->debugname.value, local->name.value, *ty}, local->location);
-                }
-            }
+                reportError(NonStrictFunctionDefinitionError{exprFn->debugname.value, local->name.value, *ty}, local->location);
             remainder.remove(dfg->getDef(local));
         }
         return remainder;

Analysis/src/Normalize.cpp

@@ -17,15 +17,11 @@
 
 LUAU_FASTFLAGVARIABLE(DebugLuauCheckNormalizeInvariant)
 
-LUAU_FASTFLAGVARIABLE(LuauNormalizeNegatedErrorToAnError)
-LUAU_FASTFLAGVARIABLE(LuauNormalizeIntersectErrorToAnError)
 LUAU_FASTINTVARIABLE(LuauNormalizeCacheLimit, 100000)
 LUAU_FASTINTVARIABLE(LuauNormalizeIntersectionLimit, 200)
-LUAU_FASTINTVARIABLE(LuauNormalizeUnionLimit, 100)
 LUAU_FASTFLAG(LuauSolverV2)
 LUAU_FASTFLAGVARIABLE(LuauFixInfiniteRecursionInNormalization)
-LUAU_FASTFLAGVARIABLE(LuauNormalizedBufferIsNotUnknown)
-LUAU_FASTFLAGVARIABLE(LuauNormalizeLimitFunctionSet)
+LUAU_FASTFLAGVARIABLE(LuauFixNormalizedIntersectionOfNegatedClass)
 
 namespace Luau
 {
@@ -307,9 +303,7 @@ bool NormalizedType::isUnknown() const
 
     // Otherwise, we can still be unknown!
     bool hasAllPrimitives = isPrim(booleans, PrimitiveType::Boolean) && isPrim(nils, PrimitiveType::NilType) && isNumber(numbers) &&
-                            strings.isString() &&
-                            (FFlag::LuauNormalizedBufferIsNotUnknown ? isThread(threads) && isBuffer(buffers)
-                                                                     : isPrim(threads, PrimitiveType::Thread) && isThread(threads));
+                            strings.isString() && isPrim(threads, PrimitiveType::Thread) && isThread(threads);
 
     // Check is class
     bool isTopClass = false;
@@ -584,7 +578,7 @@ NormalizationResult Normalizer::isIntersectionInhabited(TypeId left, TypeId righ
 {
     left = follow(left);
     right = follow(right);
-    // We're asking if intersection is inhabited between left and right but we've already seen them ....
+    // We're asking if intersection is inahbited between left and right but we've already seen them ....
 
     if (cacheInhabitance)
     {
@@ -1690,13 +1684,6 @@ NormalizationResult Normalizer::unionNormals(NormalizedType& here, const Normali
             return res;
     }
 
-    if (FFlag::LuauNormalizeLimitFunctionSet)
-    {
-        // Limit based on worst-case expansion of the function unions
-        if (here.functions.parts.size() * there.functions.parts.size() >= size_t(FInt::LuauNormalizeUnionLimit))
-            return NormalizationResult::HitLimits;
-    }
-
     here.booleans = unionOfBools(here.booleans, there.booleans);
     unionClasses(here.classes, there.classes);
 
@@ -1708,7 +1695,6 @@ NormalizationResult Normalizer::unionNormals(NormalizedType& here, const Normali
     here.buffers = (get<NeverType>(there.buffers) ? here.buffers : there.buffers);
     unionFunctions(here.functions, there.functions);
     unionTables(here.tables, there.tables);
-
     return NormalizationResult::True;
 }
 
@@ -1748,7 +1734,7 @@ NormalizationResult Normalizer::intersectNormalWithNegationTy(TypeId toNegate, N
     return NormalizationResult::True;
 }
 
-// See above for an explanation of `ignoreSmallerTyvars`.
+// See above for an explaination of `ignoreSmallerTyvars`.
 NormalizationResult Normalizer::unionNormalWithTy(
     NormalizedType& here,
     TypeId there,
@@ -2302,7 +2288,7 @@ void Normalizer::intersectClassesWithClass(NormalizedClassType& heres, TypeId th
 
             for (auto nIt = negations.begin(); nIt != negations.end();)
             {
-                if (isSubclass(there, *nIt))
+                if (FFlag::LuauFixNormalizedIntersectionOfNegatedClass && isSubclass(there, *nIt))
                 {
                     // Hitting this block means that the incoming class is a
                     // subclass of this type, _and_ one of its negations is a
@@ -3063,7 +3049,7 @@ NormalizationResult Normalizer::intersectTyvarsWithTy(
     return NormalizationResult::True;
 }
 
-// See above for an explanation of `ignoreSmallerTyvars`.
+// See above for an explaination of `ignoreSmallerTyvars`.
 NormalizationResult Normalizer::intersectNormals(NormalizedType& here, const NormalizedType& there, int ignoreSmallerTyvars)
 {
     RecursionCounter _rc(&sharedState->counters.recursionCount);
@@ -3081,17 +3067,11 @@ NormalizationResult Normalizer::intersectNormals(NormalizedType& here, const Nor
         return unionNormals(here, there, ignoreSmallerTyvars);
     }
 
-    // Limit based on worst-case expansion of the table/function intersections
+    // Limit based on worst-case expansion of the table intersection
     // This restriction can be relaxed when table intersection simplification is improved
     if (here.tables.size() * there.tables.size() >= size_t(FInt::LuauNormalizeIntersectionLimit))
         return NormalizationResult::HitLimits;
 
-    if (FFlag::LuauNormalizeLimitFunctionSet)
-    {
-        if (here.functions.parts.size() * there.functions.parts.size() >= size_t(FInt::LuauNormalizeIntersectionLimit))
-            return NormalizationResult::HitLimits;
-    }
-
     here.booleans = intersectionOfBools(here.booleans, there.booleans);
 
     intersectClasses(here.classes, there.classes);
@@ -3227,7 +3207,7 @@ NormalizationResult Normalizer::intersectNormalWithTy(
     {
         TypeId errors = here.errors;
         clearNormal(here);
-        here.errors = FFlag::LuauNormalizeIntersectErrorToAnError && get<ErrorType>(errors) ? errors : there;
+        here.errors = errors;
     }
     else if (const PrimitiveType* ptv = get<PrimitiveType>(there))
     {
@@ -3324,18 +3304,8 @@ NormalizationResult Normalizer::intersectNormalWithTy(
             clearNormal(here);
             return NormalizationResult::True;
         }
-        else if (FFlag::LuauNormalizeNegatedErrorToAnError && get<ErrorType>(t))
-        {
-            // ~error is still an error, so intersecting with the negation is the same as intersecting with a type
-            TypeId errors = here.errors;
-            clearNormal(here);
-            here.errors = FFlag::LuauNormalizeIntersectErrorToAnError && get<ErrorType>(errors) ? errors : t;
-        }
         else if (auto nt = get<NegationType>(t))
-        {
-            here.tyvars = std::move(tyvars);
             return intersectNormalWithTy(here, nt->ty, seenTablePropPairs, seenSetTypes);
-        }
         else
         {
             // TODO negated unions, intersections, table, and function.

Analysis/src/Quantify.cpp

@@ -107,4 +107,134 @@ void quantify(TypeId ty, TypeLevel level)
     ftv->genericPacks.insert(ftv->genericPacks.end(), q.genericPacks.begin(), q.genericPacks.end());
 }
 
+struct PureQuantifier : Substitution
+{
+    Scope* scope;
+    OrderedMap<TypeId, TypeId> insertedGenerics;
+    OrderedMap<TypePackId, TypePackId> insertedGenericPacks;
+    bool seenMutableType = false;
+    bool seenGenericType = false;
+
+    PureQuantifier(TypeArena* arena, Scope* scope)
+        : Substitution(TxnLog::empty(), arena)
+        , scope(scope)
+    {
+    }
+
+    bool isDirty(TypeId ty) override
+    {
+        LUAU_ASSERT(ty == follow(ty));
+
+        if (auto ftv = get<FreeType>(ty))
+        {
+            bool result = subsumes(scope, ftv->scope);
+            seenMutableType |= result;
+            return result;
+        }
+        else if (auto ttv = get<TableType>(ty))
+        {
+            if (ttv->state == TableState::Free)
+                seenMutableType = true;
+            else if (ttv->state == TableState::Generic)
+                seenGenericType = true;
+
+            return (ttv->state == TableState::Unsealed || ttv->state == TableState::Free) && subsumes(scope, ttv->scope);
+        }
+
+        return false;
+    }
+
+    bool isDirty(TypePackId tp) override
+    {
+        if (auto ftp = get<FreeTypePack>(tp))
+        {
+            return subsumes(scope, ftp->scope);
+        }
+
+        return false;
+    }
+
+    TypeId clean(TypeId ty) override
+    {
+        if (auto ftv = get<FreeType>(ty))
+        {
+            TypeId result = arena->addType(GenericType{scope});
+            insertedGenerics.push(ty, result);
+            return result;
+        }
+        else if (auto ttv = get<TableType>(ty))
+        {
+            TypeId result = arena->addType(TableType{});
+            TableType* resultTable = getMutable<TableType>(result);
+            LUAU_ASSERT(resultTable);
+
+            *resultTable = *ttv;
+            resultTable->level = TypeLevel{};
+            resultTable->scope = scope;
+
+            if (ttv->state == TableState::Free)
+            {
+                resultTable->state = TableState::Generic;
+                insertedGenerics.push(ty, result);
+            }
+            else if (ttv->state == TableState::Unsealed)
+                resultTable->state = TableState::Sealed;
+
+            return result;
+        }
+
+        return ty;
+    }
+
+    TypePackId clean(TypePackId tp) override
+    {
+        if (auto ftp = get<FreeTypePack>(tp))
+        {
+            TypePackId result = arena->addTypePack(TypePackVar{GenericTypePack{scope}});
+            insertedGenericPacks.push(tp, result);
+            return result;
+        }
+
+        return tp;
+    }
+
+    bool ignoreChildren(TypeId ty) override
+    {
+        if (get<ClassType>(ty))
+            return true;
+
+        return ty->persistent;
+    }
+    bool ignoreChildren(TypePackId ty) override
+    {
+        return ty->persistent;
+    }
+};
+
+std::optional<QuantifierResult> quantify(TypeArena* arena, TypeId ty, Scope* scope)
+{
+    PureQuantifier quantifier{arena, scope};
+    std::optional<TypeId> result = quantifier.substitute(ty);
+    if (!result)
+        return std::nullopt;
+
+    FunctionType* ftv = getMutable<FunctionType>(*result);
+    LUAU_ASSERT(ftv);
+    ftv->scope = scope;
+
+    for (auto k : quantifier.insertedGenerics.keys)
+    {
+        TypeId g = quantifier.insertedGenerics.pairings[k];
+        if (get<GenericType>(g))
+            ftv->generics.push_back(g);
+    }
+
+    for (auto k : quantifier.insertedGenericPacks.keys)
+        ftv->genericPacks.push_back(quantifier.insertedGenericPacks.pairings[k]);
+
+    ftv->hasNoFreeOrGenericTypes = ftv->generics.empty() && ftv->genericPacks.empty() && !quantifier.seenGenericType && !quantifier.seenMutableType;
+
+    return std::optional<QuantifierResult>({*result, std::move(quantifier.insertedGenerics), std::move(quantifier.insertedGenericPacks)});
+}
+
 } // namespace Luau

Analysis/src/Refinement.cpp

@@ -54,15 +54,7 @@ RefinementId RefinementArena::proposition(const RefinementKey* key, TypeId discr
     if (!key)
         return nullptr;
 
-    return NotNull{allocator.allocate(Proposition{key, discriminantTy, false})};
-}
-
-RefinementId RefinementArena::implicitProposition(const RefinementKey* key, TypeId discriminantTy)
-{
-    if (!key)
-        return nullptr;
-
-    return NotNull{allocator.allocate(Proposition{key, discriminantTy, true})};
+    return NotNull{allocator.allocate(Proposition{key, discriminantTy})};
 }
 
 } // namespace Luau

Analysis/src/RequireTracer.cpp

@@ -4,6 +4,8 @@
 #include "Luau/Ast.h"
 #include "Luau/Module.h"
 
+LUAU_FASTFLAGVARIABLE(LuauExtendedSimpleRequire)
+
 namespace Luau
 {
 
@@ -104,50 +106,96 @@ struct RequireTracer : AstVisitor
     {
         ModuleInfo moduleContext{currentModuleName};
 
-        // seed worklist with require arguments
-        work.reserve(requireCalls.size());
-
-        for (AstExprCall* require : requireCalls)
-            work.push_back(require->args.data[0]);
-
-        // push all dependent expressions to the work stack; note that the vector is modified during traversal
-        for (size_t i = 0; i < work.size(); ++i)
+        if (FFlag::LuauExtendedSimpleRequire)
         {
-            if (AstNode* dep = getDependent(work[i]))
-                work.push_back(dep);
-        }
+            // seed worklist with require arguments
+            work.reserve(requireCalls.size());
 
-        // resolve all expressions to a module info
-        for (size_t i = work.size(); i > 0; --i)
-        {
-            AstNode* expr = work[i - 1];
+            for (AstExprCall* require : requireCalls)
+                work.push_back(require->args.data[0]);
 
-            // when multiple expressions depend on the same one we push it to work queue multiple times
-            if (result.exprs.contains(expr))
-                continue;
-
-            std::optional<ModuleInfo> info;
-
-            if (AstNode* dep = getDependent(expr))
+            // push all dependent expressions to the work stack; note that the vector is modified during traversal
+            for (size_t i = 0; i < work.size(); ++i)
             {
-                const ModuleInfo* context = result.exprs.find(dep);
+                if (AstNode* dep = getDependent(work[i]))
+                    work.push_back(dep);
+            }
 
-                if (context && expr->is<AstExprLocal>())
-                    info = *context; // locals just inherit their dependent context, no resolution required
-                else if (context && (expr->is<AstExprGroup>() || expr->is<AstTypeGroup>()))
-                    info = *context; // simple group nodes propagate their value
-                else if (context && (expr->is<AstTypeTypeof>() || expr->is<AstExprTypeAssertion>()))
-                    info = *context; // typeof type annotations will resolve to the typeof content
+            // resolve all expressions to a module info
+            for (size_t i = work.size(); i > 0; --i)
+            {
+                AstNode* expr = work[i - 1];
+
+                // when multiple expressions depend on the same one we push it to work queue multiple times
+                if (result.exprs.contains(expr))
+                    continue;
+
+                std::optional<ModuleInfo> info;
+
+                if (AstNode* dep = getDependent(expr))
+                {
+                    const ModuleInfo* context = result.exprs.find(dep);
+
+                    if (context && expr->is<AstExprLocal>())
+                        info = *context; // locals just inherit their dependent context, no resolution required
+                    else if (context && (expr->is<AstExprGroup>() || expr->is<AstTypeGroup>()))
+                        info = *context; // simple group nodes propagate their value
+                    else if (context && (expr->is<AstTypeTypeof>() || expr->is<AstExprTypeAssertion>()))
+                        info = *context; // typeof type annotations will resolve to the typeof content
+                    else if (AstExpr* asExpr = expr->asExpr())
+                        info = fileResolver->resolveModule(context, asExpr);
+                }
                 else if (AstExpr* asExpr = expr->asExpr())
-                    info = fileResolver->resolveModule(context, asExpr);
-            }
-            else if (AstExpr* asExpr = expr->asExpr())
-            {
-                info = fileResolver->resolveModule(&moduleContext, asExpr);
-            }
+                {
+                    info = fileResolver->resolveModule(&moduleContext, asExpr);
+                }
 
-            if (info)
-                result.exprs[expr] = std::move(*info);
+                if (info)
+                    result.exprs[expr] = std::move(*info);
+            }
+        }
+        else
+        {
+            // seed worklist with require arguments
+            work_DEPRECATED.reserve(requireCalls.size());
+
+            for (AstExprCall* require : requireCalls)
+                work_DEPRECATED.push_back(require->args.data[0]);
+
+            // push all dependent expressions to the work stack; note that the vector is modified during traversal
+            for (size_t i = 0; i < work_DEPRECATED.size(); ++i)
+                if (AstExpr* dep = getDependent_DEPRECATED(work_DEPRECATED[i]))
+                    work_DEPRECATED.push_back(dep);
+
+            // resolve all expressions to a module info
+            for (size_t i = work_DEPRECATED.size(); i > 0; --i)
+            {
+                AstExpr* expr = work_DEPRECATED[i - 1];
+
+                // when multiple expressions depend on the same one we push it to work queue multiple times
+                if (result.exprs.contains(expr))
+                    continue;
+
+                std::optional<ModuleInfo> info;
+
+                if (AstExpr* dep = getDependent_DEPRECATED(expr))
+                {
+                    const ModuleInfo* context = result.exprs.find(dep);
+
+                    // locals just inherit their dependent context, no resolution required
+                    if (expr->is<AstExprLocal>())
+                        info = context ? std::optional<ModuleInfo>(*context) : std::nullopt;
+                    else
+                        info = fileResolver->resolveModule(context, expr);
+                }
+                else
+                {
+                    info = fileResolver->resolveModule(&moduleContext, expr);
+                }
+
+                if (info)
+                    result.exprs[expr] = std::move(*info);
+            }
         }
 
         // resolve all requires according to their argument
@@ -176,6 +224,7 @@ struct RequireTracer : AstVisitor
     ModuleName currentModuleName;
 
     DenseHashMap<AstLocal*, AstExpr*> locals;
+    std::vector<AstExpr*> work_DEPRECATED;
     std::vector<AstNode*> work;
     std::vector<AstExprCall*> requireCalls;
 };

Analysis/src/Scope.cpp

@@ -84,17 +84,6 @@ std::optional<TypeId> Scope::lookupUnrefinedType(DefId def) const
     return std::nullopt;
 }
 
-std::optional<TypeId> Scope::lookupRValueRefinementType(DefId def) const
-{
-    for (const Scope* current = this; current; current = current->parent.get())
-    {
-        if (auto ty = current->rvalueRefinements.find(def))
-            return *ty;
-    }
-
-    return std::nullopt;
-}
-
 std::optional<TypeId> Scope::lookup(DefId def) const
 {
     for (const Scope* current = this; current; current = current->parent.get())
@@ -192,29 +181,6 @@ std::optional<Binding> Scope::linearSearchForBinding(const std::string& name, bo
     return std::nullopt;
 }
 
-std::optional<std::pair<Symbol, Binding>> Scope::linearSearchForBindingPair(const std::string& name, bool traverseScopeChain) const
-{
-    const Scope* scope = this;
-
-    while (scope)
-    {
-        for (auto& [n, binding] : scope->bindings)
-        {
-            if (n.local && n.local->name == name.c_str())
-                return {{n, binding}};
-            else if (n.global.value && n.global == name.c_str())
-                return {{n, binding}};
-        }
-
-        scope = scope->parent.get();
-
-        if (!traverseScopeChain)
-            break;
-    }
-
-    return std::nullopt;
-}
-
 // Updates the `this` scope with the assignments from the `childScope` including ones that doesn't exist in `this`.
 void Scope::inheritAssignments(const ScopePtr& childScope)
 {

Analysis/src/Substitution.cpp

@@ -13,7 +13,6 @@ LUAU_FASTINTVARIABLE(LuauTarjanChildLimit, 10000)
 LUAU_FASTFLAG(LuauSolverV2)
 LUAU_FASTINTVARIABLE(LuauTarjanPreallocationSize, 256)
 LUAU_FASTFLAG(LuauSyntheticErrors)
-LUAU_FASTFLAG(LuauDeprecatedAttribute)
 
 namespace Luau
 {
@@ -103,8 +102,6 @@ static TypeId shallowClone(TypeId ty, TypeArena& dest, const TxnLog* log, bool a
             clone.tags = a.tags;
             clone.argNames = a.argNames;
             clone.isCheckedFunction = a.isCheckedFunction;
-            if (FFlag::LuauDeprecatedAttribute)
-                clone.isDeprecatedFunction = a.isDeprecatedFunction;
             return dest.addType(std::move(clone));
         }
         else if constexpr (std::is_same_v<T, TableType>)

Analysis/src/Subtyping.cpp

@@ -22,7 +22,7 @@
 #include <algorithm>
 
 LUAU_FASTFLAGVARIABLE(DebugLuauSubtypingCheckPathValidity)
-LUAU_FASTFLAGVARIABLE(LuauSubtypingStopAtNormFail)
+LUAU_FASTFLAGVARIABLE(LuauSubtypingFixTailPack)
 
 namespace Luau
 {
@@ -416,14 +416,6 @@ SubtypingResult Subtyping::isSubtype(TypeId subTy, TypeId superTy, NotNull<Scope
 
     SubtypingResult result = isCovariantWith(env, subTy, superTy, scope);
 
-    if (FFlag::LuauSubtypingStopAtNormFail && result.normalizationTooComplex)
-    {
-        if (result.isCacheable)
-            resultCache[{subTy, superTy}] = result;
-
-        return result;
-    }
-
     for (const auto& [subTy, bounds] : env.mappedGenerics)
     {
         const auto& lb = bounds.lowerBound;
@@ -601,12 +593,7 @@ SubtypingResult Subtyping::isCovariantWith(SubtypingEnvironment& env, TypeId sub
         if (!result.isSubtype && !result.normalizationTooComplex)
         {
             SubtypingResult semantic = isCovariantWith(env, normalizer->normalize(subTy), normalizer->normalize(superTy), scope);
-
-            if (FFlag::LuauSubtypingStopAtNormFail && semantic.normalizationTooComplex)
-            {
-                result = semantic;
-            }
-            else if (semantic.isSubtype)
+            if (semantic.isSubtype)
             {
                 semantic.reasoning.clear();
                 result = semantic;
@@ -621,12 +608,7 @@ SubtypingResult Subtyping::isCovariantWith(SubtypingEnvironment& env, TypeId sub
         if (!result.isSubtype && !result.normalizationTooComplex)
         {
             SubtypingResult semantic = isCovariantWith(env, normalizer->normalize(subTy), normalizer->normalize(superTy), scope);
-
-            if (FFlag::LuauSubtypingStopAtNormFail && semantic.normalizationTooComplex)
-            {
-                result = semantic;
-            }
-            else if (semantic.isSubtype)
+            if (semantic.isSubtype)
             {
                 // Clear the semantic reasoning, as any reasonings within
                 // potentially contain invalid paths.
@@ -772,8 +754,7 @@ SubtypingResult Subtyping::isCovariantWith(SubtypingEnvironment& env, TypePackId
     // Match head types pairwise
 
     for (size_t i = 0; i < headSize; ++i)
-        results.push_back(isCovariantWith(env, subHead[i], superHead[i], scope).withBothComponent(TypePath::Index{i, TypePath::Index::Variant::Pack})
-        );
+        results.push_back(isCovariantWith(env, subHead[i], superHead[i], scope).withBothComponent(TypePath::Index{i}));
 
     // Handle mismatched head sizes
 
@@ -786,7 +767,7 @@ SubtypingResult Subtyping::isCovariantWith(SubtypingEnvironment& env, TypePackId
                 for (size_t i = headSize; i < superHead.size(); ++i)
                     results.push_back(isCovariantWith(env, vt->ty, superHead[i], scope)
                                           .withSubPath(TypePath::PathBuilder().tail().variadic().build())
-                                          .withSuperComponent(TypePath::Index{i, TypePath::Index::Variant::Pack}));
+                                          .withSuperComponent(TypePath::Index{i}));
             }
             else if (auto gt = get<GenericTypePack>(*subTail))
             {
@@ -840,7 +821,7 @@ SubtypingResult Subtyping::isCovariantWith(SubtypingEnvironment& env, TypePackId
             {
                 for (size_t i = headSize; i < subHead.size(); ++i)
                     results.push_back(isCovariantWith(env, subHead[i], vt->ty, scope)
-                                          .withSubComponent(TypePath::Index{i, TypePath::Index::Variant::Pack})
+                                          .withSubComponent(TypePath::Index{i})
                                           .withSuperPath(TypePath::PathBuilder().tail().variadic().build()));
             }
             else if (auto gt = get<GenericTypePack>(*superTail))
@@ -878,7 +859,7 @@ SubtypingResult Subtyping::isCovariantWith(SubtypingEnvironment& env, TypePackId
             else
                 return SubtypingResult{false}
                     .withSuperComponent(TypePath::PackField::Tail)
-                    .withError({scope->location, UnexpectedTypePackInSubtyping{*superTail}});
+                    .withError({scope->location, UnexpectedTypePackInSubtyping{FFlag::LuauSubtypingFixTailPack ? *superTail : *subTail}});
         }
         else
             return {false};
@@ -1101,10 +1082,6 @@ SubtypingResult Subtyping::isCovariantWith(SubtypingEnvironment& env, TypeId sub
     for (TypeId ty : superUnion)
     {
         SubtypingResult next = isCovariantWith(env, subTy, ty, scope);
-
-        if (FFlag::LuauSubtypingStopAtNormFail && next.normalizationTooComplex)
-            return SubtypingResult{false, /* normalizationTooComplex */ true};
-
         if (next.isSubtype)
             return SubtypingResult{true};
     }
@@ -1123,13 +1100,7 @@ SubtypingResult Subtyping::isCovariantWith(SubtypingEnvironment& env, const Unio
     std::vector<SubtypingResult> subtypings;
     size_t i = 0;
     for (TypeId ty : subUnion)
-    {
-        subtypings.push_back(isCovariantWith(env, ty, superTy, scope).withSubComponent(TypePath::Index{i++, TypePath::Index::Variant::Union}));
-
-        if (FFlag::LuauSubtypingStopAtNormFail && subtypings.back().normalizationTooComplex)
-            return SubtypingResult{false, /* normalizationTooComplex */ true};
-    }
-
+        subtypings.push_back(isCovariantWith(env, ty, superTy, scope).withSubComponent(TypePath::Index{i++}));
     return SubtypingResult::all(subtypings);
 }
 
@@ -1139,13 +1110,7 @@ SubtypingResult Subtyping::isCovariantWith(SubtypingEnvironment& env, TypeId sub
     std::vector<SubtypingResult> subtypings;
     size_t i = 0;
     for (TypeId ty : superIntersection)
-    {
-        subtypings.push_back(isCovariantWith(env, subTy, ty, scope).withSuperComponent(TypePath::Index{i++, TypePath::Index::Variant::Intersection}));
-
-        if (FFlag::LuauSubtypingStopAtNormFail && subtypings.back().normalizationTooComplex)
-            return SubtypingResult{false, /* normalizationTooComplex */ true};
-    }
-
+        subtypings.push_back(isCovariantWith(env, subTy, ty, scope).withSuperComponent(TypePath::Index{i++}));
     return SubtypingResult::all(subtypings);
 }
 
@@ -1155,13 +1120,7 @@ SubtypingResult Subtyping::isCovariantWith(SubtypingEnvironment& env, const Inte
     std::vector<SubtypingResult> subtypings;
     size_t i = 0;
     for (TypeId ty : subIntersection)
-    {
-        subtypings.push_back(isCovariantWith(env, ty, superTy, scope).withSubComponent(TypePath::Index{i++, TypePath::Index::Variant::Intersection}));
-
-        if (FFlag::LuauSubtypingStopAtNormFail && subtypings.back().normalizationTooComplex)
-            return SubtypingResult{false, /* normalizationTooComplex */ true};
-    }
-
+        subtypings.push_back(isCovariantWith(env, ty, superTy, scope).withSubComponent(TypePath::Index{i++}));
     return SubtypingResult::any(subtypings);
 }
 
@@ -1451,7 +1410,7 @@ SubtypingResult Subtyping::isCovariantWith(SubtypingEnvironment& env, const Meta
         // of the supertype table.
         //
         // There's a flaw here in that if the __index metamethod contributes a new
-        // field that would satisfy the subtyping relationship, we'll erroneously say
+        // field that would satisfy the subtyping relationship, we'll erronously say
         // that the metatable isn't a subtype of the table, even though they have
         // compatible properties/shapes. We'll revisit this later when we have a
         // better understanding of how important this is.
@@ -1801,12 +1760,7 @@ SubtypingResult Subtyping::isCovariantWith(SubtypingEnvironment& env, const Type
     {
         results.emplace_back();
         for (TypeId superTy : superTypes)
-        {
             results.back().orElse(isCovariantWith(env, subTy, superTy, scope));
-
-            if (FFlag::LuauSubtypingStopAtNormFail && results.back().normalizationTooComplex)
-                return SubtypingResult{false, /* normalizationTooComplex */ true};
-        }
     }
 
     return SubtypingResult::all(results);

Analysis/src/Symbol.cpp

@@ -4,6 +4,7 @@
 #include "Luau/Common.h"
 
 LUAU_FASTFLAG(LuauSolverV2)
+LUAU_FASTFLAGVARIABLE(LuauSymbolEquality)
 
 namespace Luau
 {
@@ -14,8 +15,10 @@ bool Symbol::operator==(const Symbol& rhs) const
         return local == rhs.local;
     else if (global.value)
         return rhs.global.value && global == rhs.global.value; // Subtlety: AstName::operator==(const char*) uses strcmp, not pointer identity.
-    else
+    else if (FFlag::LuauSolverV2 || FFlag::LuauSymbolEquality)
         return !rhs.local && !rhs.global.value; // Reflexivity: we already know `this` Symbol is empty, so check that rhs is.
+    else
+        return false;
 }
 
 std::string toString(const Symbol& name)

Analysis/src/TableLiteralInference.cpp

@@ -1,21 +1,16 @@
 // This file is part of the Luau programming language and is licensed under MIT License; see LICENSE.txt for details
 
-#include "Luau/TableLiteralInference.h"
-
 #include "Luau/Ast.h"
-#include "Luau/Common.h"
 #include "Luau/Normalize.h"
 #include "Luau/Simplify.h"
-#include "Luau/Subtyping.h"
 #include "Luau/Type.h"
 #include "Luau/ToString.h"
 #include "Luau/TypeArena.h"
 #include "Luau/TypeUtils.h"
 #include "Luau/Unifier2.h"
 
-LUAU_FASTFLAGVARIABLE(LuauBidirectionalInferenceUpcast)
-LUAU_FASTFLAGVARIABLE(LuauBidirectionalInferenceCollectIndexerTypes)
-LUAU_FASTFLAGVARIABLE(LuauBidirectionalFailsafe)
+LUAU_FASTFLAGVARIABLE(LuauDontInPlaceMutateTableType)
+LUAU_FASTFLAGVARIABLE(LuauAllowNonSharedTableTypesInLiteral)
 
 namespace Luau
 {
@@ -117,7 +112,6 @@ TypeId matchLiteralType(
     NotNull<BuiltinTypes> builtinTypes,
     NotNull<TypeArena> arena,
     NotNull<Unifier2> unifier,
-    NotNull<Subtyping> subtyping,
     TypeId expectedType,
     TypeId exprType,
     const AstExpr* expr,
@@ -138,38 +132,17 @@ TypeId matchLiteralType(
      * things like replace explicit named properties with indexers as required
      * by the expected type.
      */
-
     if (!isLiteral(expr))
-    {
-        if (FFlag::LuauBidirectionalInferenceUpcast)
-        {
-            auto result = subtyping->isSubtype(/*subTy=*/exprType, /*superTy=*/expectedType, unifier->scope);
-            return result.isSubtype ? expectedType : exprType;
-        }
-        else
-            return exprType;
-    }
+        return exprType;
 
     expectedType = follow(expectedType);
     exprType = follow(exprType);
 
-    if (FFlag::LuauBidirectionalInferenceCollectIndexerTypes)
+    if (get<AnyType>(expectedType) || get<UnknownType>(expectedType))
     {
-        // The intent of `matchLiteralType` is to upcast values when it's safe
-        // to do so. it's always safe to upcast to `any` or `unknown`, so we
-        // can unconditionally do so here.
-        if (is<AnyType, UnknownType>(expectedType))
-            return expectedType;
+        // "Narrowing" to unknown or any is not going to do anything useful.
+        return exprType;
     }
-    else
-    {
-        if (get<AnyType>(expectedType) || get<UnknownType>(expectedType))
-        {
-            // "Narrowing" to unknown or any is not going to do anything useful.
-            return exprType;
-        }
-    }
-
 
     if (expr->is<AstExprConstantString>())
     {
@@ -237,29 +210,11 @@ TypeId matchLiteralType(
         return exprType;
     }
 
-
-    if (FFlag::LuauBidirectionalInferenceUpcast && expr->is<AstExprFunction>())
-    {
-        // TODO: Push argument / return types into the lambda. For now, just do 
-        // the non-literal thing: check for a subtype and upcast if valid.
-        auto result = subtyping->isSubtype(/*subTy=*/exprType, /*superTy=*/expectedType, unifier->scope);
-        return result.isSubtype 
-            ? expectedType
-            : exprType;
-    }
+    // TODO: lambdas
 
     if (auto exprTable = expr->as<AstExprTable>())
     {
         TableType* const tableTy = getMutable<TableType>(exprType);
-
-        // This can occur if we have an expression like:
-        //
-        //  { x = {}, x = 42 }
-        //
-        // The type of this will be `{ x: number }`
-        if (FFlag::LuauBidirectionalFailsafe && !tableTy)
-            return exprType;
-
         LUAU_ASSERT(tableTy);
 
         const TableType* expectedTableTy = get<TableType>(expectedType);
@@ -274,7 +229,7 @@ TypeId matchLiteralType(
 
                 if (tt)
                 {
-                    TypeId res = matchLiteralType(astTypes, astExpectedTypes, builtinTypes, arena, unifier, subtyping, *tt, exprType, expr, toBlock);
+                    TypeId res = matchLiteralType(astTypes, astExpectedTypes, builtinTypes, arena, unifier, *tt, exprType, expr, toBlock);
 
                     parts.push_back(res);
                     return arena->addType(UnionType{std::move(parts)});
@@ -286,9 +241,6 @@ TypeId matchLiteralType(
 
         DenseHashSet<AstExprConstantString*> keysToDelete{nullptr};
 
-        DenseHashSet<TypeId> indexerKeyTypes{nullptr};
-        DenseHashSet<TypeId> indexerValueTypes{nullptr};
-
         for (const AstExprTable::Item& item : exprTable->items)
         {
             if (isRecord(item))
@@ -296,20 +248,23 @@ TypeId matchLiteralType(
                 const AstArray<char>& s = item.key->as<AstExprConstantString>()->value;
                 std::string keyStr{s.data, s.data + s.size};
                 auto it = tableTy->props.find(keyStr);
-
-                // This can occur, potentially, if we are re-entrant.
-                if (FFlag::LuauBidirectionalFailsafe && it == tableTy->props.end())
-                    continue;
-
                 LUAU_ASSERT(it != tableTy->props.end());
 
                 Property& prop = it->second;
 
-                // If we encounter a duplcate property, we may have already
-                // set it to be read-only. If that's the case, the only thing
-                // that will definitely crash is trying to access a write
-                // only property.
-                LUAU_ASSERT(!prop.isWriteOnly());
+                if (FFlag::LuauAllowNonSharedTableTypesInLiteral)
+                {
+                    // If we encounter a duplcate property, we may have already
+                    // set it to be read-only. If that's the case, the only thing
+                    // that will definitely crash is trying to access a write
+                    // only property.
+                    LUAU_ASSERT(!prop.isWriteOnly());
+                }
+                else
+                {
+                    // Table literals always initially result in shared read-write types
+                    LUAU_ASSERT(prop.isShared());
+                }
                 TypeId propTy = *prop.readTy;
 
                 auto it2 = expectedTableTy->props.find(keyStr);
@@ -330,28 +285,21 @@ TypeId matchLiteralType(
                             builtinTypes,
                             arena,
                             unifier,
-                            subtyping,
                             expectedTableTy->indexer->indexResultType,
                             propTy,
                             item.value,
                             toBlock
                         );
 
-                        if (FFlag::LuauBidirectionalInferenceCollectIndexerTypes)
-                        {
-                            indexerKeyTypes.insert(arena->addType(SingletonType{StringSingleton{keyStr}}));
-                            indexerValueTypes.insert(matchedType);
-                        }
+                        if (tableTy->indexer)
+                            unifier->unify(matchedType, tableTy->indexer->indexResultType);
                         else
-                        {
-                            if (tableTy->indexer)
-                                unifier->unify(matchedType, tableTy->indexer->indexResultType);
-                            else
-                                tableTy->indexer = TableIndexer{expectedTableTy->indexer->indexType, matchedType};
-                        }
-
-                        keysToDelete.insert(item.key->as<AstExprConstantString>());
+                            tableTy->indexer = TableIndexer{expectedTableTy->indexer->indexType, matchedType};
 
+                        if (FFlag::LuauDontInPlaceMutateTableType)
+                            keysToDelete.insert(item.key->as<AstExprConstantString>());
+                        else
+                            tableTy->props.erase(keyStr);
                     }
 
                     // If it's just an extra property and the expected type
@@ -375,21 +323,21 @@ TypeId matchLiteralType(
                 if (expectedProp.isShared())
                 {
                     matchedType =
-                        matchLiteralType(astTypes, astExpectedTypes, builtinTypes, arena, unifier, subtyping, *expectedReadTy, propTy, item.value, toBlock);
+                        matchLiteralType(astTypes, astExpectedTypes, builtinTypes, arena, unifier, *expectedReadTy, propTy, item.value, toBlock);
                     prop.readTy = matchedType;
                     prop.writeTy = matchedType;
                 }
                 else if (expectedReadTy)
                 {
                     matchedType =
-                        matchLiteralType(astTypes, astExpectedTypes, builtinTypes, arena, unifier, subtyping, *expectedReadTy, propTy, item.value, toBlock);
+                        matchLiteralType(astTypes, astExpectedTypes, builtinTypes, arena, unifier, *expectedReadTy, propTy, item.value, toBlock);
                     prop.readTy = matchedType;
                     prop.writeTy.reset();
                 }
                 else if (expectedWriteTy)
                 {
                     matchedType =
-                        matchLiteralType(astTypes, astExpectedTypes, builtinTypes, arena, unifier, subtyping, *expectedWriteTy, propTy, item.value, toBlock);
+                        matchLiteralType(astTypes, astExpectedTypes, builtinTypes, arena, unifier, *expectedWriteTy, propTy, item.value, toBlock);
                     prop.readTy.reset();
                     prop.writeTy = matchedType;
                 }
@@ -406,11 +354,6 @@ TypeId matchLiteralType(
                 LUAU_ASSERT(matchedType);
 
                 (*astExpectedTypes)[item.value] = matchedType;
-                // NOTE: We do *not* add to the potential indexer types here.
-                // I think this is correct to support something like:
-                //
-                //  { [string]: number, foo: boolean }
-                //
             }
             else if (item.kind == AstExprTable::Item::List)
             {
@@ -428,25 +371,15 @@ TypeId matchLiteralType(
                         builtinTypes,
                         arena,
                         unifier,
-                        subtyping,
                         expectedTableTy->indexer->indexResultType,
                         *propTy,
                         item.value,
                         toBlock
                     );
 
-                    if (FFlag::LuauBidirectionalInferenceCollectIndexerTypes)
-                    {
-                        indexerKeyTypes.insert(builtinTypes->numberType);
-                        indexerValueTypes.insert(matchedType);
-                    }
-                    else
-                    {
-                        // if the index result type is the prop type, we can replace it with the matched type here.
-                        if (tableTy->indexer->indexResultType == *propTy)
-                            tableTy->indexer->indexResultType = matchedType;
-                    }
-
+                    // if the index result type is the prop type, we can replace it with the matched type here.
+                    if (tableTy->indexer->indexResultType == *propTy)
+                        tableTy->indexer->indexResultType = matchedType;
                 }
             }
             else if (item.kind == AstExprTable::Item::General)
@@ -468,23 +401,19 @@ TypeId matchLiteralType(
                 // Populate expected types for non-string keys declared with [] (the code below will handle the case where they are strings)
                 if (!item.key->as<AstExprConstantString>() && expectedTableTy->indexer)
                     (*astExpectedTypes)[item.key] = expectedTableTy->indexer->indexType;
-
-                if (FFlag::LuauBidirectionalInferenceCollectIndexerTypes)
-                {
-                    indexerKeyTypes.insert(tKey);
-                    indexerValueTypes.insert(tProp);
-                }
-
             }
             else
                 LUAU_ASSERT(!"Unexpected");
         }
 
-        for (const auto& key : keysToDelete)
+        if (FFlag::LuauDontInPlaceMutateTableType)
         {
-            const AstArray<char>& s = key->value;
-            std::string keyStr{s.data, s.data + s.size};
-            tableTy->props.erase(keyStr);
+            for (const auto& key : keysToDelete)
+            {
+                const AstArray<char>& s = key->value;
+                std::string keyStr{s.data, s.data + s.size};
+                tableTy->props.erase(keyStr);
+            }
         }
 
         // Keys that the expectedType says we should have, but that aren't
@@ -536,39 +465,9 @@ TypeId matchLiteralType(
         // have one too.
         // TODO: If the expected table also has an indexer, we might want to
         // push the expected indexer's types into it.
-        if (FFlag::LuauBidirectionalInferenceCollectIndexerTypes && expectedTableTy->indexer)
+        if (expectedTableTy->indexer && !tableTy->indexer)
         {
-            if (indexerValueTypes.size() > 0 && indexerKeyTypes.size() > 0)
-            {
-                TypeId inferredKeyType = builtinTypes->neverType;
-                TypeId inferredValueType = builtinTypes->neverType;
-                for (auto kt: indexerKeyTypes)
-                {
-                    auto simplified = simplifyUnion(builtinTypes, arena, inferredKeyType, kt);
-                    inferredKeyType = simplified.result;
-                }
-                for (auto vt: indexerValueTypes)
-                {
-                    auto simplified = simplifyUnion(builtinTypes, arena, inferredValueType, vt);
-                    inferredValueType = simplified.result;
-                }
-                tableTy->indexer = TableIndexer{inferredKeyType, inferredValueType};
-                auto keyCheck = subtyping->isSubtype(inferredKeyType, expectedTableTy->indexer->indexType, unifier->scope);
-                if (keyCheck.isSubtype)
-                    tableTy->indexer->indexType = expectedTableTy->indexer->indexType;
-                auto valueCheck = subtyping->isSubtype(inferredValueType, expectedTableTy->indexer->indexResultType, unifier->scope);
-                if (valueCheck.isSubtype)
-                    tableTy->indexer->indexResultType = expectedTableTy->indexer->indexResultType;
-            }
-            else
-                LUAU_ASSERT(indexerKeyTypes.empty() && indexerValueTypes.empty());
-        }
-        else
-        {
-            if (expectedTableTy->indexer && !tableTy->indexer)
-            {
-                tableTy->indexer = expectedTableTy->indexer;
-            }
+            tableTy->indexer = expectedTableTy->indexer;
         }
     }
 

Analysis/src/Transpiler.cpp

@@ -10,12 +10,10 @@
 #include <limits>
 #include <math.h>
 
-LUAU_FASTFLAG(LuauStoreCSTData2)
+LUAU_FASTFLAG(LuauStoreCSTData)
 LUAU_FASTFLAG(LuauExtendStatEndPosWithSemicolon)
-LUAU_FASTFLAG(LuauAstTypeGroup3)
+LUAU_FASTFLAG(LuauAstTypeGroup)
 LUAU_FASTFLAG(LuauFixDoBlockEndLocation)
-LUAU_FASTFLAG(LuauParseOptionalAsNode2)
-LUAU_FASTFLAG(LuauFixFunctionWithAttributesStartLocation)
 
 namespace
 {
@@ -168,7 +166,7 @@ struct StringWriter : Writer
 
     void symbol(std::string_view s) override
     {
-        if (FFlag::LuauStoreCSTData2)
+        if (FFlag::LuauStoreCSTData)
         {
             write(s);
         }
@@ -258,7 +256,7 @@ public:
             first = !first;
         else
         {
-            if (FFlag::LuauStoreCSTData2 && commaPosition)
+            if (FFlag::LuauStoreCSTData && commaPosition)
             {
                 writer.advance(*commaPosition);
                 commaPosition++;
@@ -273,43 +271,6 @@ private:
     const Position* commaPosition;
 };
 
-class ArgNameInserter
-{
-public:
-    ArgNameInserter(Writer& w, AstArray<std::optional<AstArgumentName>> names, AstArray<std::optional<Position>> colonPositions)
-        : writer(w)
-        , names(names)
-        , colonPositions(colonPositions)
-    {
-    }
-
-    void operator()()
-    {
-        if (idx < names.size)
-        {
-            const auto name = names.data[idx];
-            if (name.has_value())
-            {
-                writer.advance(name->second.begin);
-                writer.identifier(name->first.value);
-                if (idx < colonPositions.size)
-                {
-                    LUAU_ASSERT(colonPositions.data[idx].has_value());
-                    writer.advance(*colonPositions.data[idx]);
-                }
-                writer.symbol(":");
-            }
-        }
-        idx++;
-    }
-
-private:
-    Writer& writer;
-    AstArray<std::optional<AstArgumentName>> names;
-    AstArray<std::optional<Position>> colonPositions;
-    size_t idx = 0;
-};
-
 struct Printer_DEPRECATED
 {
     explicit Printer_DEPRECATED(Writer& writer)
@@ -369,7 +330,7 @@ struct Printer_DEPRECATED
         else if (typeCount == 1)
         {
             bool shouldParenthesize = unconditionallyParenthesize && (list.types.size == 0 || !list.types.data[0]->is<AstTypeGroup>());
-            if (FFlag::LuauAstTypeGroup3 ? shouldParenthesize : unconditionallyParenthesize)
+            if (FFlag::LuauAstTypeGroup ? shouldParenthesize : unconditionallyParenthesize)
                 writer.symbol("(");
 
             // Only variadic tail
@@ -382,7 +343,7 @@ struct Printer_DEPRECATED
                 visualizeTypeAnnotation(*list.types.data[0]);
             }
 
-            if (FFlag::LuauAstTypeGroup3 ? shouldParenthesize : unconditionallyParenthesize)
+            if (FFlag::LuauAstTypeGroup ? shouldParenthesize : unconditionallyParenthesize)
                 writer.symbol(")");
         }
         else
@@ -1230,18 +1191,9 @@ struct Printer_DEPRECATED
                 AstType* l = a->types.data[0];
                 AstType* r = a->types.data[1];
 
-                if (FFlag::LuauParseOptionalAsNode2)
-                {
-                    auto lta = l->as<AstTypeReference>();
-                    if (lta && lta->name == "nil" && !r->is<AstTypeOptional>())
-                        std::swap(l, r);
-                }
-                else
-                {
-                    auto lta = l->as<AstTypeReference>();
-                    if (lta && lta->name == "nil")
-                        std::swap(l, r);
-                }
+                auto lta = l->as<AstTypeReference>();
+                if (lta && lta->name == "nil")
+                    std::swap(l, r);
 
                 // it's still possible that we had a (T | U) or (T | nil) and not (nil | T)
                 auto rta = r->as<AstTypeReference>();
@@ -1264,15 +1216,6 @@ struct Printer_DEPRECATED
 
             for (size_t i = 0; i < a->types.size; ++i)
             {
-                if (FFlag::LuauParseOptionalAsNode2)
-                {
-                    if (a->types.data[i]->is<AstTypeOptional>())
-                    {
-                        writer.symbol("?");
-                        continue;
-                    }
-                }
-
                 if (i > 0)
                 {
                     writer.maybeSpace(a->types.data[i]->location.begin, 2);
@@ -1369,7 +1312,7 @@ struct Printer
         }
     }
 
-    void visualizeTypePackAnnotation(AstTypePack& annotation, bool forVarArg)
+    void visualizeTypePackAnnotation(const AstTypePack& annotation, bool forVarArg)
     {
         advance(annotation.location.begin);
         if (const AstTypePackVariadic* variadicTp = annotation.as<AstTypePackVariadic>())
@@ -1379,22 +1322,15 @@ struct Printer
 
             visualizeTypeAnnotation(*variadicTp->variadicType);
         }
-        else if (AstTypePackGeneric* genericTp = annotation.as<AstTypePackGeneric>())
+        else if (const AstTypePackGeneric* genericTp = annotation.as<AstTypePackGeneric>())
         {
             writer.symbol(genericTp->genericName.value);
-            if (const auto cstNode = lookupCstNode<CstTypePackGeneric>(genericTp))
-                advance(cstNode->ellipsisPosition);
             writer.symbol("...");
         }
-        else if (AstTypePackExplicit* explicitTp = annotation.as<AstTypePackExplicit>())
+        else if (const AstTypePackExplicit* explicitTp = annotation.as<AstTypePackExplicit>())
         {
             LUAU_ASSERT(!forVarArg);
-            if (const auto cstNode = lookupCstNode<CstTypePackExplicit>(explicitTp))
-                visualizeTypeList(
-                    explicitTp->typeList, true, cstNode->openParenthesesPosition, cstNode->closeParenthesesPosition, cstNode->commaPositions
-                );
-            else
-                visualizeTypeList(explicitTp->typeList, true);
+            visualizeTypeList(explicitTp->typeList, true);
         }
         else
         {
@@ -1402,37 +1338,19 @@ struct Printer
         }
     }
 
-    void visualizeNamedTypeList(
-        const AstTypeList& list,
-        bool unconditionallyParenthesize,
-        std::optional<Position> openParenthesesPosition,
-        std::optional<Position> closeParenthesesPosition,
-        AstArray<Position> commaPositions,
-        AstArray<std::optional<AstArgumentName>> argNames,
-        AstArray<std::optional<Position>> argNamesColonPositions
-    )
+    void visualizeTypeList(const AstTypeList& list, bool unconditionallyParenthesize)
     {
         size_t typeCount = list.types.size + (list.tailType != nullptr ? 1 : 0);
         if (typeCount == 0)
         {
-            if (openParenthesesPosition)
-                advance(*openParenthesesPosition);
             writer.symbol("(");
-            if (closeParenthesesPosition)
-                advance(*closeParenthesesPosition);
             writer.symbol(")");
         }
         else if (typeCount == 1)
         {
             bool shouldParenthesize = unconditionallyParenthesize && (list.types.size == 0 || !list.types.data[0]->is<AstTypeGroup>());
-            if (FFlag::LuauAstTypeGroup3 ? shouldParenthesize : unconditionallyParenthesize)
-            {
-                if (openParenthesesPosition)
-                    advance(*openParenthesesPosition);
+            if (FFlag::LuauAstTypeGroup ? shouldParenthesize : unconditionallyParenthesize)
                 writer.symbol("(");
-            }
-
-            ArgNameInserter(writer, argNames, argNamesColonPositions)();
 
             // Only variadic tail
             if (list.types.size == 0)
@@ -1444,51 +1362,34 @@ struct Printer
                 visualizeTypeAnnotation(*list.types.data[0]);
             }
 
-            if (FFlag::LuauAstTypeGroup3 ? shouldParenthesize : unconditionallyParenthesize)
-            {
-                if (closeParenthesesPosition)
-                    advance(*closeParenthesesPosition);
+            if (FFlag::LuauAstTypeGroup ? shouldParenthesize : unconditionallyParenthesize)
                 writer.symbol(")");
-            }
         }
         else
         {
-            if (openParenthesesPosition)
-                advance(*openParenthesesPosition);
             writer.symbol("(");
 
-            CommaSeparatorInserter comma(writer, commaPositions.size > 0 ? commaPositions.begin() : nullptr);
-            ArgNameInserter argName(writer, argNames, argNamesColonPositions);
+            bool first = true;
             for (const auto& el : list.types)
             {
-                comma();
-                argName();
+                if (first)
+                    first = false;
+                else
+                    writer.symbol(",");
+
                 visualizeTypeAnnotation(*el);
             }
 
             if (list.tailType)
             {
-                comma();
+                writer.symbol(",");
                 visualizeTypePackAnnotation(*list.tailType, false);
             }
 
-            if (closeParenthesesPosition)
-                advance(*closeParenthesesPosition);
             writer.symbol(")");
         }
     }
 
-    void visualizeTypeList(
-        const AstTypeList& list,
-        bool unconditionallyParenthesize,
-        std::optional<Position> openParenthesesPosition = std::nullopt,
-        std::optional<Position> closeParenthesesPosition = std::nullopt,
-        AstArray<Position> commaPositions = {}
-    )
-    {
-        visualizeNamedTypeList(list, unconditionallyParenthesize, openParenthesesPosition, closeParenthesesPosition, commaPositions, {}, {});
-    }
-
     bool isIntegerish(double d)
     {
         if (d <= std::numeric_limits<int>::max() && d >= std::numeric_limits<int>::min())
@@ -1499,14 +1400,13 @@ struct Printer
 
     void visualize(AstExpr& expr)
     {
-        if (!expr.is<AstExprFunction>() || FFlag::LuauFixFunctionWithAttributesStartLocation)
-            advance(expr.location.begin);
+        advance(expr.location.begin);
 
         if (const auto& a = expr.as<AstExprGroup>())
         {
             writer.symbol("(");
             visualize(*a->expr);
-            advanceBefore(a->location.end, 1);
+            advance(Position{a->location.end.line, a->location.end.column - 1});
             writer.symbol(")");
         }
         else if (expr.is<AstExprConstantNil>())
@@ -1634,17 +1534,6 @@ struct Printer
         }
         else if (const auto& a = expr.as<AstExprFunction>())
         {
-            for (const auto& attribute : a->attributes)
-                visualizeAttribute(*attribute);
-            if (FFlag::LuauFixFunctionWithAttributesStartLocation)
-            {
-                if (const auto cstNode = lookupCstNode<CstExprFunction>(a))
-                    advance(cstNode->functionKeywordPosition);
-            }
-            else
-            {
-                advance(a->location.begin);
-            }
             writer.keyword("function");
             visualizeFunctionBody(*a);
         }
@@ -1886,18 +1775,9 @@ struct Printer
         writer.advance(newPos);
     }
 
-    void advanceBefore(const Position& newPos, unsigned int tokenLength)
-    {
-        if (newPos.column >= tokenLength)
-            advance(Position{newPos.line, newPos.column - tokenLength});
-        else
-            advance(newPos);
-    }
-
     void visualize(AstStat& program)
     {
-        if ((!program.is<AstStatLocalFunction>() && !program.is<AstStatFunction>()) || FFlag::LuauFixFunctionWithAttributesStartLocation)
-            advance(program.location.begin);
+        advance(program.location.begin);
 
         if (const auto& block = program.as<AstStatBlock>())
         {
@@ -1937,8 +1817,8 @@ struct Printer
             visualizeBlock(*a->body);
             if (const auto cstNode = lookupCstNode<CstStatRepeat>(a))
                 writer.advance(cstNode->untilPosition);
-            else
-                advanceBefore(a->condition->location.begin, 6);
+            else if (a->condition->location.begin.column > 5)
+                writer.advance(Position{a->condition->location.begin.line, a->condition->location.begin.column - 6});
             writer.keyword("until");
             visualize(*a->condition);
         }
@@ -2134,36 +2014,13 @@ struct Printer
         }
         else if (const auto& a = program.as<AstStatFunction>())
         {
-            for (const auto& attribute : a->func->attributes)
-                visualizeAttribute(*attribute);
-            if (FFlag::LuauFixFunctionWithAttributesStartLocation)
-            {
-                if (const auto cstNode = lookupCstNode<CstStatFunction>(a))
-                    advance(cstNode->functionKeywordPosition);
-            }
-            else
-            {
-                advance(a->location.begin);
-            }
             writer.keyword("function");
             visualize(*a->name);
             visualizeFunctionBody(*a->func);
         }
         else if (const auto& a = program.as<AstStatLocalFunction>())
         {
-            for (const auto& attribute : a->func->attributes)
-                visualizeAttribute(*attribute);
-
             const auto cstNode = lookupCstNode<CstStatLocalFunction>(a);
-            if (FFlag::LuauFixFunctionWithAttributesStartLocation)
-            {
-                if (cstNode)
-                    advance(cstNode->localKeywordPosition);
-            }
-            else
-            {
-                advance(a->location.begin);
-            }
 
             writer.keyword("local");
 
@@ -2264,20 +2121,7 @@ struct Printer
         {
             if (writeTypes)
             {
-                const auto cstNode = lookupCstNode<CstStatTypeFunction>(t);
-                if (t->exported)
-                    writer.keyword("export");
-                if (cstNode)
-                    advance(cstNode->typeKeywordPosition);
-                else
-                    writer.space();
-                writer.keyword("type");
-                if (cstNode)
-                    advance(cstNode->functionKeywordPosition);
-                else
-                    writer.space();
-                writer.keyword("function");
-                advance(t->nameLocation.begin);
+                writer.keyword("type function");
                 writer.identifier(t->name.value);
                 visualizeFunctionBody(*t->body);
             }
@@ -2307,23 +2151,17 @@ struct Printer
 
         if (program.hasSemicolon)
         {
-            if (FFlag::LuauStoreCSTData2)
-                advanceBefore(program.location.end, 1);
+            if (FFlag::LuauStoreCSTData)
+                advance(Position{program.location.end.line, program.location.end.column - 1});
             writer.symbol(";");
         }
     }
 
     void visualizeFunctionBody(AstExprFunction& func)
     {
-        const auto cstNode = lookupCstNode<CstExprFunction>(&func);
-
-        // TODO(CLI-139347): need to handle return type (incl. parentheses of return type)
-
         if (func.generics.size > 0 || func.genericPacks.size > 0)
         {
-            CommaSeparatorInserter comma(writer, cstNode ? cstNode->genericsCommaPositions.begin() : nullptr);
-            if (cstNode)
-                advance(cstNode->openGenericsPosition);
+            CommaSeparatorInserter comma(writer);
             writer.symbol("<");
             for (const auto& o : func.generics)
             {
@@ -2338,19 +2176,13 @@ struct Printer
 
                 writer.advance(o->location.begin);
                 writer.identifier(o->name.value);
-                if (const auto* genericTypePackCstNode = lookupCstNode<CstGenericTypePack>(o))
-                    advance(genericTypePackCstNode->ellipsisPosition);
                 writer.symbol("...");
             }
-            if (cstNode)
-                advance(cstNode->closeGenericsPosition);
             writer.symbol(">");
         }
 
-        if (func.argLocation)
-            advance(func.argLocation->begin);
         writer.symbol("(");
-        CommaSeparatorInserter comma(writer, cstNode ? cstNode->argsCommaPositions.begin() : nullptr);
+        CommaSeparatorInserter comma(writer);
 
         for (size_t i = 0; i < func.args.size; ++i)
         {
@@ -2380,14 +2212,10 @@ struct Printer
             }
         }
 
-        if (func.argLocation)
-            advanceBefore(func.argLocation->end, 1);
         writer.symbol(")");
 
         if (writeTypes && func.returnAnnotation)
         {
-            if (cstNode)
-                advance(cstNode->returnSpecifierPosition);
             writer.symbol(":");
             writer.space();
 
@@ -2473,23 +2301,6 @@ struct Printer
         }
     }
 
-    void visualizeAttribute(AstAttr& attribute)
-    {
-        advance(attribute.location.begin);
-        switch (attribute.type)
-        {
-        case AstAttr::Checked:
-            writer.keyword("@checked");
-            break;
-        case AstAttr::Native:
-            writer.keyword("@native");
-            break;
-        case AstAttr::Deprecated:
-            writer.keyword("@deprecated");
-            break;
-        }
-    }
-
     void visualizeTypeAnnotation(AstType& typeAnnotation)
     {
         advance(typeAnnotation.location.begin);
@@ -2529,13 +2340,9 @@ struct Printer
         }
         else if (const auto& a = typeAnnotation.as<AstTypeFunction>())
         {
-            const auto cstNode = lookupCstNode<CstTypeFunction>(a);
-
             if (a->generics.size > 0 || a->genericPacks.size > 0)
             {
-                CommaSeparatorInserter comma(writer, cstNode ? cstNode->genericsCommaPositions.begin() : nullptr);
-                if (cstNode)
-                    advance(cstNode->openGenericsPosition);
+                CommaSeparatorInserter comma(writer);
                 writer.symbol("<");
                 for (const auto& o : a->generics)
                 {
@@ -2550,29 +2357,15 @@ struct Printer
 
                     writer.advance(o->location.begin);
                     writer.identifier(o->name.value);
-                    if (const auto* genericTypePackCstNode = lookupCstNode<CstGenericTypePack>(o))
-                        advance(genericTypePackCstNode->ellipsisPosition);
                     writer.symbol("...");
                 }
-                if (cstNode)
-                    advance(cstNode->closeGenericsPosition);
                 writer.symbol(">");
             }
 
             {
-                visualizeNamedTypeList(
-                    a->argTypes,
-                    true,
-                    cstNode ? std::make_optional(cstNode->openArgsPosition) : std::nullopt,
-                    cstNode ? std::make_optional(cstNode->closeArgsPosition) : std::nullopt,
-                    cstNode ? cstNode->argumentsCommaPositions : Luau::AstArray<Position>{},
-                    a->argNames,
-                    cstNode ? cstNode->argumentNameColonPositions : Luau::AstArray<std::optional<Position>>{}
-                );
+                visualizeTypeList(a->argTypes, true);
             }
 
-            if (cstNode)
-                advance(cstNode->returnArrowPosition);
             writer.symbol("->");
             visualizeTypeList(a->returnTypes, true);
         }
@@ -2734,25 +2527,14 @@ struct Printer
         }
         else if (const auto& a = typeAnnotation.as<AstTypeUnion>())
         {
-            const auto cstNode = lookupCstNode<CstTypeUnion>(a);
-
-            if (!cstNode && a->types.size == 2)
+            if (a->types.size == 2)
             {
                 AstType* l = a->types.data[0];
                 AstType* r = a->types.data[1];
 
-                if (FFlag::LuauParseOptionalAsNode2)
-                {
-                    auto lta = l->as<AstTypeReference>();
-                    if (lta && lta->name == "nil" && !r->is<AstTypeOptional>())
-                        std::swap(l, r);
-                }
-                else
-                {
-                    auto lta = l->as<AstTypeReference>();
-                    if (lta && lta->name == "nil")
-                        std::swap(l, r);
-                }
+                auto lta = l->as<AstTypeReference>();
+                if (lta && lta->name == "nil")
+                    std::swap(l, r);
 
                 // it's still possible that we had a (T | U) or (T | nil) and not (nil | T)
                 auto rta = r->as<AstTypeReference>();
@@ -2773,39 +2555,15 @@ struct Printer
                 }
             }
 
-            if (cstNode && cstNode->leadingPosition)
-            {
-                advance(*cstNode->leadingPosition);
-                writer.symbol("|");
-            }
-
-            size_t separatorIndex = 0;
             for (size_t i = 0; i < a->types.size; ++i)
             {
-                if (FFlag::LuauParseOptionalAsNode2)
-                {
-                    if (const auto optional = a->types.data[i]->as<AstTypeOptional>())
-                    {
-                        advance(optional->location.begin);
-                        writer.symbol("?");
-                        continue;
-                    }
-                }
-
                 if (i > 0)
                 {
-                    if (cstNode && FFlag::LuauParseOptionalAsNode2)
-                    {
-                        // separatorIndex is only valid if `?` is handled as an AstTypeOptional
-                        advance(cstNode->separatorPositions.data[separatorIndex]);
-                        separatorIndex++;
-                    }
-                    else
-                        writer.maybeSpace(a->types.data[i]->location.begin, 2);
+                    writer.maybeSpace(a->types.data[i]->location.begin, 2);
                     writer.symbol("|");
                 }
 
-                bool wrap = !cstNode && (a->types.data[i]->as<AstTypeIntersection>() || a->types.data[i]->as<AstTypeFunction>());
+                bool wrap = a->types.data[i]->as<AstTypeIntersection>() || a->types.data[i]->as<AstTypeFunction>();
 
                 if (wrap)
                     writer.symbol("(");
@@ -2818,27 +2576,15 @@ struct Printer
         }
         else if (const auto& a = typeAnnotation.as<AstTypeIntersection>())
         {
-            const auto cstNode = lookupCstNode<CstTypeIntersection>(a);
-
-            // If the sizes are equal, we know there is a leading & token
-            if (cstNode && cstNode->leadingPosition)
-            {
-                advance(*cstNode->leadingPosition);
-                writer.symbol("&");
-            }
-
             for (size_t i = 0; i < a->types.size; ++i)
             {
                 if (i > 0)
                 {
-                    if (cstNode)
-                        advance(cstNode->separatorPositions.data[i - 1]);
-                    else
-                        writer.maybeSpace(a->types.data[i]->location.begin, 2);
+                    writer.maybeSpace(a->types.data[i]->location.begin, 2);
                     writer.symbol("&");
                 }
 
-                bool wrap = !cstNode && (a->types.data[i]->as<AstTypeUnion>() || a->types.data[i]->as<AstTypeFunction>());
+                bool wrap = a->types.data[i]->as<AstTypeUnion>() || a->types.data[i]->as<AstTypeFunction>();
 
                 if (wrap)
                     writer.symbol("(");
@@ -2853,7 +2599,6 @@ struct Printer
         {
             writer.symbol("(");
             visualizeTypeAnnotation(*a->type);
-            advanceBefore(a->location.end, 1);
             writer.symbol(")");
         }
         else if (const auto& a = typeAnnotation.as<AstTypeSingletonBool>())
@@ -2887,7 +2632,7 @@ std::string toString(AstNode* node)
     StringWriter writer;
     writer.pos = node->location.begin;
 
-    if (FFlag::LuauStoreCSTData2)
+    if (FFlag::LuauStoreCSTData)
     {
         Printer printer(writer, CstNodeMap{nullptr});
         printer.writeTypes = true;
@@ -2923,7 +2668,7 @@ void dump(AstNode* node)
 std::string transpile(AstStatBlock& block, const CstNodeMap& cstNodeMap)
 {
     StringWriter writer;
-    if (FFlag::LuauStoreCSTData2)
+    if (FFlag::LuauStoreCSTData)
     {
         Printer(writer, cstNodeMap).visualizeBlock(block);
     }
@@ -2937,7 +2682,7 @@ std::string transpile(AstStatBlock& block, const CstNodeMap& cstNodeMap)
 std::string transpileWithTypes(AstStatBlock& block, const CstNodeMap& cstNodeMap)
 {
     StringWriter writer;
-    if (FFlag::LuauStoreCSTData2)
+    if (FFlag::LuauStoreCSTData)
     {
         Printer printer(writer, cstNodeMap);
         printer.writeTypes = true;

Analysis/src/TypeAttach.cpp

@@ -13,8 +13,6 @@
 
 #include <string>
 
-LUAU_FASTFLAG(LuauStoreCSTData2)
-
 static char* allocateString(Luau::Allocator& allocator, std::string_view contents)
 {
     char* result = (char*)allocator.allocate(contents.size() + 1);
@@ -307,8 +305,7 @@ public:
             std::optional<AstArgumentName>* arg = &argNames.data[i++];
 
             if (el)
-                new (arg)
-                    std::optional<AstArgumentName>(AstArgumentName(AstName(el->name.c_str()), FFlag::LuauStoreCSTData2 ? Location() : el->location));
+                new (arg) std::optional<AstArgumentName>(AstArgumentName(AstName(el->name.c_str()), el->location));
             else
                 new (arg) std::optional<AstArgumentName>();
         }

Analysis/src/TypeChecker2.cpp

@@ -26,14 +26,11 @@
 #include "Luau/VisitType.h"
 
 #include <algorithm>
-#include <sstream>
 
 LUAU_FASTFLAG(DebugLuauMagicTypes)
 
+LUAU_FASTFLAGVARIABLE(LuauTableKeysAreRValues)
 LUAU_FASTFLAG(LuauFreeTypesMustHaveBounds)
-LUAU_FASTFLAGVARIABLE(LuauImproveTypePathsInErrors)
-LUAU_FASTFLAG(LuauUserTypeFunTypecheck)
-LUAU_FASTFLAGVARIABLE(LuauTypeCheckerAcceptNumberConcats)
 
 namespace Luau
 {
@@ -1205,8 +1202,7 @@ void TypeChecker2::visit(AstStatTypeAlias* stat)
 
 void TypeChecker2::visit(AstStatTypeFunction* stat)
 {
-    if (FFlag::LuauUserTypeFunTypecheck)
-        visit(stat->body);
+    // TODO: add type checking for user-defined type functions
 }
 
 void TypeChecker2::visit(AstTypeList types)
@@ -1852,8 +1848,16 @@ void TypeChecker2::visit(AstExprTable* expr)
 {
     for (const AstExprTable::Item& item : expr->items)
     {
-        if (item.key)
-            visit(item.key, ValueContext::RValue);
+        if (FFlag::LuauTableKeysAreRValues)
+        {
+            if (item.key)
+                visit(item.key, ValueContext::RValue);
+        }
+        else
+        {
+            if (item.key)
+                visit(item.key, ValueContext::LValue);
+        }
         visit(item.value, ValueContext::RValue);
     }
 }
@@ -2230,21 +2234,10 @@ TypeId TypeChecker2::visit(AstExprBinary* expr, AstNode* overrideKey)
 
         return builtinTypes->numberType;
     case AstExprBinary::Op::Concat:
-    {
-        if (FFlag::LuauTypeCheckerAcceptNumberConcats)
-        {
-            const TypeId numberOrString = module->internalTypes.addType(UnionType{{builtinTypes->numberType, builtinTypes->stringType}});
-            testIsSubtype(leftType, numberOrString, expr->left->location);
-            testIsSubtype(rightType, numberOrString, expr->right->location);
-        }
-        else
-        {
-            testIsSubtype(leftType, builtinTypes->stringType, expr->left->location);
-            testIsSubtype(rightType, builtinTypes->stringType, expr->right->location);
-        }
+        testIsSubtype(leftType, builtinTypes->stringType, expr->left->location);
+        testIsSubtype(rightType, builtinTypes->stringType, expr->right->location);
 
         return builtinTypes->stringType;
-    }
     case AstExprBinary::Op::CompareGe:
     case AstExprBinary::Op::CompareGt:
     case AstExprBinary::Op::CompareLe:
@@ -2717,61 +2710,20 @@ Reasonings TypeChecker2::explainReasonings_(TID subTy, TID superTy, Location loc
         if (!subLeafTy && !superLeafTy && !subLeafTp && !superLeafTp)
             ice->ice("Subtyping test returned a reasoning where one path ends at a type and the other ends at a pack.", location);
 
-        if (FFlag::LuauImproveTypePathsInErrors)
-        {
-            std::string relation = "a subtype of";
-            if (reasoning.variance == SubtypingVariance::Invariant)
-                relation = "exactly";
-            else if (reasoning.variance == SubtypingVariance::Contravariant)
-                relation = "a supertype of";
+        std::string relation = "a subtype of";
+        if (reasoning.variance == SubtypingVariance::Invariant)
+            relation = "exactly";
+        else if (reasoning.variance == SubtypingVariance::Contravariant)
+            relation = "a supertype of";
 
-            std::string subLeafAsString = toString(subLeaf);
-            // if the string is empty, it must be an empty type pack
-            if (subLeafAsString.empty())
-                subLeafAsString = "()";
-
-            std::string superLeafAsString = toString(superLeaf);
-            // if the string is empty, it must be an empty type pack
-            if (superLeafAsString.empty())
-                superLeafAsString = "()";
-
-            std::stringstream baseReasonBuilder;
-            baseReasonBuilder << "`" << subLeafAsString << "` is not " << relation << " `" << superLeafAsString << "`";
-            std::string baseReason = baseReasonBuilder.str();
-
-            std::stringstream reason;
-
-            if (reasoning.subPath == reasoning.superPath)
-                reason << toStringHuman(reasoning.subPath) << "`" << subLeafAsString << "` in the former type and `" << superLeafAsString
-                       << "` in the latter type, and " << baseReason;
-            else if (!reasoning.subPath.empty() && !reasoning.superPath.empty())
-                reason << toStringHuman(reasoning.subPath) << "`" << subLeafAsString << "` and " << toStringHuman(reasoning.superPath) << "`"
-                       << superLeafAsString << "`, and " << baseReason;
-            else if (!reasoning.subPath.empty())
-                reason << toStringHuman(reasoning.subPath) << "`" << subLeafAsString << "`, which is not " << relation << " `" << superLeafAsString
-                       << "`";
-            else
-                reason << toStringHuman(reasoning.superPath) << "`" << superLeafAsString << "`, and " << baseReason;
-
-            reasons.push_back(reason.str());
-        }
+        std::string reason;
+        if (reasoning.subPath == reasoning.superPath)
+            reason = "at " + toString(reasoning.subPath) + ", " + toString(subLeaf) + " is not " + relation + " " + toString(superLeaf);
         else
-        {
-            std::string relation = "a subtype of";
-            if (reasoning.variance == SubtypingVariance::Invariant)
-                relation = "exactly";
-            else if (reasoning.variance == SubtypingVariance::Contravariant)
-                relation = "a supertype of";
+            reason = "type " + toString(subTy) + toString(reasoning.subPath, /* prefixDot */ true) + " (" + toString(subLeaf) + ") is not " +
+                     relation + " " + toString(superTy) + toString(reasoning.superPath, /* prefixDot */ true) + " (" + toString(superLeaf) + ")";
 
-            std::string reason;
-            if (reasoning.subPath == reasoning.superPath)
-                reason = "at " + toString(reasoning.subPath) + ", " + toString(subLeaf) + " is not " + relation + " " + toString(superLeaf);
-            else
-                reason = "type " + toString(subTy) + toString(reasoning.subPath, /* prefixDot */ true) + " (" + toString(subLeaf) + ") is not " +
-                         relation + " " + toString(superTy) + toString(reasoning.superPath, /* prefixDot */ true) + " (" + toString(superLeaf) + ")";
-
-            reasons.push_back(reason);
-        }
+        reasons.push_back(reason);
 
         // if we haven't already proved this isn't suppressing, we have to keep checking.
         if (suppressed)

Analysis/src/TypeFunctionRuntime.cpp

@@ -13,8 +13,11 @@
 #include <set>
 #include <vector>
 
+LUAU_FASTFLAGVARIABLE(LuauTypeFunFixHydratedClasses)
 LUAU_DYNAMIC_FASTINT(LuauTypeFunctionSerdeIterationLimit)
-LUAU_FASTFLAGVARIABLE(LuauTypeFunReadWriteParents)
+LUAU_FASTFLAGVARIABLE(LuauTypeFunSingletonEquality)
+LUAU_FASTFLAGVARIABLE(LuauUserTypeFunTypeofReturnsType)
+LUAU_FASTFLAGVARIABLE(LuauTypeFunPrintFix)
 
 namespace Luau
 {
@@ -1107,7 +1110,7 @@ static int getFunctionGenerics(lua_State* L)
 
 // Luau: `self:parent() -> type`
 // Returns the parent of a class type
-static int getClassParent_DEPRECATED(lua_State* L)
+static int getClassParent(lua_State* L)
 {
     int argumentCount = lua_gettop(L);
     if (argumentCount != 1)
@@ -1119,54 +1122,10 @@ static int getClassParent_DEPRECATED(lua_State* L)
         luaL_error(L, "type.parent: expected self to be a class, but got %s instead", getTag(L, self).c_str());
 
     // If the parent does not exist, we should return nil
-    if (!tfct->parent_DEPRECATED)
+    if (!tfct->parent)
         lua_pushnil(L);
     else
-        allocTypeUserData(L, (*tfct->parent_DEPRECATED)->type);
-
-    return 1;
-}
-
-// Luau: `self:readparent() -> type`
-// Returns the read type of the class' parent
-static int getReadParent(lua_State* L)
-{
-    int argumentCount = lua_gettop(L);
-    if (argumentCount != 1)
-        luaL_error(L, "type.parent: expected 1 arguments, but got %d", argumentCount);
-
-    TypeFunctionTypeId self = getTypeUserData(L, 1);
-    auto tfct = get<TypeFunctionClassType>(self);
-    if (!tfct)
-        luaL_error(L, "type.parent: expected self to be a class, but got %s instead", getTag(L, self).c_str());
-
-    // If the parent does not exist, we should return nil
-    if (!tfct->readParent)
-        lua_pushnil(L);
-    else
-        allocTypeUserData(L, (*tfct->readParent)->type);
-
-    return 1;
-}
-//
-// Luau: `self:writeparent() -> type`
-// Returns the write type of the class' parent
-static int getWriteParent(lua_State* L)
-{
-    int argumentCount = lua_gettop(L);
-    if (argumentCount != 1)
-        luaL_error(L, "type.parent: expected 1 arguments, but got %d", argumentCount);
-
-    TypeFunctionTypeId self = getTypeUserData(L, 1);
-    auto tfct = get<TypeFunctionClassType>(self);
-    if (!tfct)
-        luaL_error(L, "type.parent: expected self to be a class, but got %s instead", getTag(L, self).c_str());
-
-    // If the parent does not exist, we should return nil
-    if (!tfct->writeParent)
-        lua_pushnil(L);
-    else
-        allocTypeUserData(L, (*tfct->writeParent)->type);
+        allocTypeUserData(L, (*tfct->parent)->type);
 
     return 1;
 }
@@ -1594,7 +1553,7 @@ void registerTypeUserData(lua_State* L)
         {"components", getComponents},
 
         // Class type methods
-        {FFlag::LuauTypeFunReadWriteParents ? "readparent" : "parent", FFlag::LuauTypeFunReadWriteParents ? getReadParent : getClassParent_DEPRECATED},
+        {"parent", getClassParent},
 
         // Function type methods (cont.)
         {"setgenerics", setFunctionGenerics},
@@ -1604,17 +1563,17 @@ void registerTypeUserData(lua_State* L)
         {"name", getGenericName},
         {"ispack", getGenericIsPack},
 
-        // move this under Class type methods when removing FFlagLuauTypeFunReadWriteParents
-        {FFlag::LuauTypeFunReadWriteParents ? "writeparent" : nullptr, FFlag::LuauTypeFunReadWriteParents ? getWriteParent : nullptr},
-
         {nullptr, nullptr}
     };
 
     // Create and register metatable for type userdata
     luaL_newmetatable(L, "type");
 
-    lua_pushstring(L, "type");
-    lua_setfield(L, -2, "__type");
+    if (FFlag::LuauUserTypeFunTypeofReturnsType)
+    {
+        lua_pushstring(L, "type");
+        lua_setfield(L, -2, "__type");
+    }
 
     // Protect metatable from being changed
     lua_pushstring(L, "The metatable is locked");
@@ -1655,7 +1614,10 @@ static int print(lua_State* L)
         const char* s = luaL_tolstring(L, i, &l); // convert to string using __tostring et al
         if (i > 1)
         {
-            result.append(1, '\t');
+            if (FFlag::LuauTypeFunPrintFix)
+                result.append(1, '\t');
+            else
+                result.append('\t', 1);
         }
         result.append(s, l);
         lua_pop(L, 1);
@@ -1748,14 +1710,14 @@ bool areEqual(SeenSet& seen, const TypeFunctionSingletonType& lhs, const TypeFun
 
     {
         const TypeFunctionBooleanSingleton* lp = get<TypeFunctionBooleanSingleton>(&lhs);
-        const TypeFunctionBooleanSingleton* rp = get<TypeFunctionBooleanSingleton>(&rhs);
+        const TypeFunctionBooleanSingleton* rp = get<TypeFunctionBooleanSingleton>(FFlag::LuauTypeFunSingletonEquality ? &rhs : &lhs);
         if (lp && rp)
             return lp->value == rp->value;
     }
 
     {
         const TypeFunctionStringSingleton* lp = get<TypeFunctionStringSingleton>(&lhs);
-        const TypeFunctionStringSingleton* rp = get<TypeFunctionStringSingleton>(&rhs);
+        const TypeFunctionStringSingleton* rp = get<TypeFunctionStringSingleton>(FFlag::LuauTypeFunSingletonEquality ? &rhs : &lhs);
         if (lp && rp)
             return lp->value == rp->value;
     }
@@ -1908,7 +1870,10 @@ bool areEqual(SeenSet& seen, const TypeFunctionClassType& lhs, const TypeFunctio
     if (seenSetContains(seen, &lhs, &rhs))
         return true;
 
-    return lhs.classTy == rhs.classTy;
+    if (FFlag::LuauTypeFunFixHydratedClasses)
+        return lhs.classTy == rhs.classTy;
+    else
+        return lhs.name_DEPRECATED == rhs.name_DEPRECATED;
 }
 
 bool areEqual(SeenSet& seen, const TypeFunctionType& lhs, const TypeFunctionType& rhs)

Analysis/src/TypeFunctionRuntimeBuilder.cpp

@@ -19,7 +19,7 @@
 // used to control the recursion limit of any operations done by user-defined type functions
 // currently, controls serialization, deserialization, and `type.copy`
 LUAU_DYNAMIC_FASTINTVARIABLE(LuauTypeFunctionSerdeIterationLimit, 100'000);
-LUAU_FASTFLAG(LuauTypeFunReadWriteParents)
+LUAU_FASTFLAG(LuauTypeFunFixHydratedClasses)
 
 namespace Luau
 {
@@ -208,11 +208,19 @@ private:
         }
         else if (auto c = get<ClassType>(ty))
         {
-            // Since there aren't any new class types being created in type functions, we will deserialize by using a direct reference to the original
-            // class
-            target = typeFunctionRuntime->typeArena.allocate(
-                TypeFunctionClassType{{}, std::nullopt, std::nullopt, std::nullopt, std::nullopt, std::nullopt, ty}
-            );
+            if (FFlag::LuauTypeFunFixHydratedClasses)
+            {
+                // Since there aren't any new class types being created in type functions, we will deserialize by using a direct reference to the
+                // original class
+                target = typeFunctionRuntime->typeArena.allocate(TypeFunctionClassType{{}, std::nullopt, std::nullopt, std::nullopt, ty});
+            }
+            else
+            {
+                state->classesSerialized_DEPRECATED[c->name] = ty;
+                target = typeFunctionRuntime->typeArena.allocate(
+                    TypeFunctionClassType{{}, std::nullopt, std::nullopt, std::nullopt, /* classTy */ nullptr, c->name}
+                );
+            }
         }
         else if (auto g = get<GenericType>(ty))
         {
@@ -433,20 +441,7 @@ private:
             c2->metatable = shallowSerialize(*c1->metatable);
 
         if (c1->parent)
-        {
-            TypeFunctionTypeId parent = shallowSerialize(*c1->parent);
-
-            if (FFlag::LuauTypeFunReadWriteParents)
-            {
-                // we don't yet have read/write parents in the type inference engine.
-                c2->readParent = parent;
-                c2->writeParent = parent;
-            }
-            else
-            {
-                c2->parent_DEPRECATED = parent;
-            }
-        }
+            c2->parent = shallowSerialize(*c1->parent);
     }
 
     void serializeChildren(const GenericType* g1, TypeFunctionGenericType* g2)
@@ -704,7 +699,17 @@ private:
         }
         else if (auto c = get<TypeFunctionClassType>(ty))
         {
-            target = c->classTy;
+            if (FFlag::LuauTypeFunFixHydratedClasses)
+            {
+                target = c->classTy;
+            }
+            else
+            {
+                if (auto result = state->classesSerialized_DEPRECATED.find(c->name_DEPRECATED))
+                    target = *result;
+                else
+                    state->ctx->ice->ice("Deserializing user defined type function arguments: mysterious class type is being deserialized");
+            }
         }
         else if (auto g = get<TypeFunctionGenericType>(ty))
         {

Analysis/src/TypeInfer.cpp

@@ -32,11 +32,10 @@ LUAU_FASTINTVARIABLE(LuauVisitRecursionLimit, 500)
 LUAU_FASTFLAG(LuauKnowsTheDataModel3)
 LUAU_FASTFLAGVARIABLE(DebugLuauFreezeDuringUnification)
 LUAU_FASTFLAG(LuauInstantiateInSubtyping)
+LUAU_FASTFLAGVARIABLE(LuauOldSolverCreatesChildScopePointers)
 LUAU_FASTFLAG(LuauPreserveUnionIntersectionNodeForLeadingTokenSingleType)
 LUAU_FASTFLAG(LuauFreeTypesMustHaveBounds)
 
-LUAU_FASTFLAG(LuauModuleHoldsAstRoot)
-
 namespace Luau
 {
 
@@ -256,8 +255,6 @@ ModulePtr TypeChecker::checkWithoutRecursionCheck(const SourceModule& module, Mo
     currentModule->type = module.type;
     currentModule->allocator = module.allocator;
     currentModule->names = module.names;
-    if (FFlag::LuauModuleHoldsAstRoot)
-        currentModule->root = module.root;
 
     iceHandler->moduleName = module.name;
     normalizer.arena = &currentModule->internalTypes;
@@ -5215,9 +5212,12 @@ LUAU_NOINLINE void TypeChecker::reportErrorCodeTooComplex(const Location& locati
 ScopePtr TypeChecker::childFunctionScope(const ScopePtr& parent, const Location& location, int subLevel)
 {
     ScopePtr scope = std::make_shared<Scope>(parent, subLevel);
-    scope->location = location;
-    scope->returnType = parent->returnType;
-    parent->children.emplace_back(scope.get());
+    if (FFlag::LuauOldSolverCreatesChildScopePointers)
+    {
+        scope->location = location;
+        scope->returnType = parent->returnType;
+        parent->children.emplace_back(scope.get());
+    }
 
     currentModule->scopes.push_back(std::make_pair(location, scope));
     return scope;
@@ -5229,9 +5229,12 @@ ScopePtr TypeChecker::childScope(const ScopePtr& parent, const Location& locatio
     ScopePtr scope = std::make_shared<Scope>(parent);
     scope->level = parent->level;
     scope->varargPack = parent->varargPack;
-    scope->location = location;
-    scope->returnType = parent->returnType;
-    parent->children.emplace_back(scope.get());
+    if (FFlag::LuauOldSolverCreatesChildScopePointers)
+    {
+        scope->location = location;
+        scope->returnType = parent->returnType;
+        parent->children.emplace_back(scope.get());
+    }
 
     currentModule->scopes.push_back(std::make_pair(location, scope));
     return scope;
@@ -5721,10 +5724,6 @@ TypeId TypeChecker::resolveTypeWorker(const ScopePtr& scope, const AstType& anno
         TypeId ty = checkExpr(scope, *typeOf->expr).type;
         return ty;
     }
-    else if (annotation.is<AstTypeOptional>())
-    {
-        return builtinTypes->nilType;
-    }
     else if (const auto& un = annotation.as<AstTypeUnion>())
     {
         if (FFlag::LuauPreserveUnionIntersectionNodeForLeadingTokenSingleType)

Analysis/src/TypePath.cpp

@@ -14,7 +14,6 @@
 #include <type_traits>
 
 LUAU_FASTFLAG(LuauSolverV2);
-LUAU_FASTFLAGVARIABLE(LuauDisableNewSolverAssertsInMixedMode)
 
 // Maximum number of steps to follow when traversing a path. May not always
 // equate to the number of components in a path, depending on the traversal
@@ -157,16 +156,14 @@ Path PathBuilder::build()
 
 PathBuilder& PathBuilder::readProp(std::string name)
 {
-    if (!FFlag::LuauDisableNewSolverAssertsInMixedMode)
-        LUAU_ASSERT(FFlag::LuauSolverV2);
+    LUAU_ASSERT(FFlag::LuauSolverV2);
     components.push_back(Property{std::move(name), true});
     return *this;
 }
 
 PathBuilder& PathBuilder::writeProp(std::string name)
 {
-    if (!FFlag::LuauDisableNewSolverAssertsInMixedMode)
-        LUAU_ASSERT(FFlag::LuauSolverV2);
+    LUAU_ASSERT(FFlag::LuauSolverV2);
     components.push_back(Property{std::move(name), false});
     return *this;
 }
@@ -639,247 +636,6 @@ std::string toString(const TypePath::Path& path, bool prefixDot)
     return result.str();
 }
 
-std::string toStringHuman(const TypePath::Path& path)
-{
-    LUAU_ASSERT(FFlag::LuauSolverV2);
-
-    enum class State
-    {
-        Initial,
-        Normal,
-        Property,
-        PendingIs,
-        PendingAs,
-        PendingWhich,
-    };
-
-    std::stringstream result;
-    State state = State::Initial;
-    bool last = false;
-
-    auto strComponent = [&](auto&& c)
-    {
-        using T = std::decay_t<decltype(c)>;
-        if constexpr (std::is_same_v<T, TypePath::Property>)
-        {
-            if (state == State::PendingIs)
-                result << ", ";
-
-            switch (state)
-            {
-            case State::Initial:
-            case State::PendingIs:
-                if (c.isRead)
-                    result << "accessing `";
-                else
-                    result << "writing to `";
-                break;
-            case State::Property:
-                // if the previous state was a property, then we're doing a sequence of indexing
-                result << '.';
-                break;
-            default:
-                break;
-            }
-
-            result << c.name;
-
-            state = State::Property;
-        }
-        else if constexpr (std::is_same_v<T, TypePath::Index>)
-        {
-            size_t humanIndex = c.index + 1;
-
-            if (state == State::Initial && !last)
-                result << "in" << ' ';
-            else if (state == State::PendingIs)
-                result << ' ' << "has" << ' ';
-            else if (state == State::Property)
-                result << '`' << ' ' << "has" << ' ';
-
-            result << "the " << humanIndex;
-            switch (humanIndex)
-            {
-            case 1:
-                result << "st";
-                break;
-            case 2:
-                result << "nd";
-                break;
-            case 3:
-                result << "rd";
-                break;
-            default:
-                result << "th";
-            }
-
-            switch (c.variant)
-            {
-            case TypePath::Index::Variant::Pack:
-                result << ' ' << "entry in the type pack";
-                break;
-            case TypePath::Index::Variant::Union:
-                result << ' ' << "component of the union";
-                break;
-            case TypePath::Index::Variant::Intersection:
-                result << ' ' << "component of the intersection";
-                break;
-            }
-
-            if (state == State::PendingWhich)
-                result << ' ' << "which";
-
-            if (state == State::PendingIs || state == State::Property)
-                state = State::PendingAs;
-            else
-                state = State::PendingIs;
-        }
-        else if constexpr (std::is_same_v<T, TypePath::TypeField>)
-        {
-            if (state == State::Initial && !last)
-                result << "in" << ' ';
-            else if (state == State::PendingIs)
-                result << ", ";
-            else if (state == State::Property)
-                result << '`' << ' ' << "has" << ' ';
-
-            switch (c)
-            {
-            case TypePath::TypeField::Table:
-                result << "the table portion";
-                if (state == State::Property)
-                    state = State::PendingAs;
-                else
-                    state = State::PendingIs;
-                break;
-            case TypePath::TypeField::Metatable:
-                result << "the metatable portion";
-                if (state == State::Property)
-                    state = State::PendingAs;
-                else
-                    state = State::PendingIs;
-                break;
-            case TypePath::TypeField::LowerBound:
-                result << "the lower bound of" << ' ';
-                state = State::Normal;
-                break;
-            case TypePath::TypeField::UpperBound:
-                result << "the upper bound of" << ' ';
-                state = State::Normal;
-                break;
-            case TypePath::TypeField::IndexLookup:
-                result << "the index type";
-                if (state == State::Property)
-                    state = State::PendingAs;
-                else
-                    state = State::PendingIs;
-                break;
-            case TypePath::TypeField::IndexResult:
-                result << "the result of indexing";
-                if (state == State::Property)
-                    state = State::PendingAs;
-                else
-                    state = State::PendingIs;
-                break;
-            case TypePath::TypeField::Negated:
-                result << "the negation" << ' ';
-                state = State::Normal;
-                break;
-            case TypePath::TypeField::Variadic:
-                result << "the variadic" << ' ';
-                state = State::Normal;
-                break;
-            }
-        }
-        else if constexpr (std::is_same_v<T, TypePath::PackField>)
-        {
-            if (state == State::PendingIs)
-                result << ", ";
-            else if (state == State::Property)
-                result << "`, ";
-
-            switch (c)
-            {
-            case TypePath::PackField::Arguments:
-                if (state == State::Initial)
-                    result << "it" << ' ';
-                else if (state == State::PendingIs)
-                    result << "the function" << ' ';
-
-                result << "takes";
-                break;
-            case TypePath::PackField::Returns:
-                if (state == State::Initial)
-                    result << "it" << ' ';
-                else if (state == State::PendingIs)
-                    result << "the function" << ' ';
-
-                result << "returns";
-                break;
-            case TypePath::PackField::Tail:
-                if (state == State::Initial)
-                    result << "it has" << ' ';
-                result << "a tail of";
-                break;
-            }
-
-            if (state == State::PendingIs)
-            {
-                result << ' ';
-                state = State::PendingWhich;
-            }
-            else
-            {
-                result << ' ';
-                state = State::Normal;
-            }
-        }
-        else if constexpr (std::is_same_v<T, TypePath::Reduction>)
-        {
-            if (state == State::Initial)
-                result << "it" << ' ';
-            result << "reduces to" << ' ';
-            state = State::Normal;
-        }
-        else
-        {
-            static_assert(always_false_v<T>, "Unhandled Component variant");
-        }
-    };
-
-    size_t count = 0;
-
-    for (const TypePath::Component& component : path.components)
-    {
-        count++;
-        if (count == path.components.size())
-            last = true;
-
-        Luau::visit(strComponent, component);
-    }
-
-    switch (state)
-    {
-    case State::Property:
-        result << "` results in ";
-        break;
-    case State::PendingWhich:
-        // pending `which` becomes `is` if it's at the end
-        result << "is" << ' ';
-        break;
-    case State::PendingIs:
-        result << ' ' << "is" << ' ';
-        break;
-    case State::PendingAs:
-        result << ' ' << "as" << ' ';
-        break;
-    default:
-        break;
-    }
-
-    return result.str();
-}
-
 static bool traverse(TraversalState& state, const Path& path)
 {
     auto step = [&state](auto&& c)

Analysis/src/TypeUtils.cpp

@@ -14,7 +14,7 @@ LUAU_FASTFLAG(LuauSolverV2);
 LUAU_FASTFLAG(LuauAutocompleteRefactorsForIncrementalAutocomplete);
 LUAU_FASTFLAG(LuauTrackInteriorFreeTypesOnScope);
 LUAU_FASTFLAG(LuauFreeTypesMustHaveBounds)
-LUAU_FASTFLAG(LuauDisableNewSolverAssertsInMixedMode)
+
 namespace Luau
 {
 
@@ -550,10 +550,7 @@ std::vector<TypeId> findBlockedArgTypesIn(AstExprCall* expr, NotNull<DenseHashMa
 
 void trackInteriorFreeType(Scope* scope, TypeId ty)
 {
-    if (FFlag::LuauDisableNewSolverAssertsInMixedMode)
-        LUAU_ASSERT(FFlag::LuauTrackInteriorFreeTypesOnScope);
-    else
-        LUAU_ASSERT(FFlag::LuauSolverV2 && FFlag::LuauTrackInteriorFreeTypesOnScope);
+    LUAU_ASSERT(FFlag::LuauSolverV2 && FFlag::LuauTrackInteriorFreeTypesOnScope);
     for (; scope; scope = scope->parent.get())
     {
         if (scope->interiorFreeTypes)

Analysis/src/TypedAllocator.cpp

@@ -24,7 +24,6 @@ const size_t kPageSize = sysconf(_SC_PAGESIZE);
 #endif
 #endif
 
-#include <stdint.h>
 #include <stdlib.h>
 
 LUAU_FASTFLAG(DebugLuauFreezeArena)

Analysis/src/Unifier.cpp

@@ -33,20 +33,38 @@ struct PromoteTypeLevels final : TypeOnceVisitor
     const TypeArena* typeArena = nullptr;
     TypeLevel minLevel;
 
-    PromoteTypeLevels(TxnLog& log, const TypeArena* typeArena, TypeLevel minLevel)
+    Scope* outerScope = nullptr;
+    bool useScopes;
+
+    PromoteTypeLevels(TxnLog& log, const TypeArena* typeArena, TypeLevel minLevel, Scope* outerScope, bool useScopes)
         : log(log)
         , typeArena(typeArena)
         , minLevel(minLevel)
+        , outerScope(outerScope)
+        , useScopes(useScopes)
     {
     }
 
     template<typename TID, typename T>
     void promote(TID ty, T* t)
     {
+        if (useScopes && !t)
+            return;
+
         LUAU_ASSERT(t);
 
-        if (minLevel.subsumesStrict(t->level))
-            log.changeLevel(ty, minLevel);
+        if (useScopes)
+        {
+            if (subsumesStrict(outerScope, t->scope))
+                log.changeScope(ty, NotNull{outerScope});
+        }
+        else
+        {
+            if (minLevel.subsumesStrict(t->level))
+            {
+                log.changeLevel(ty, minLevel);
+            }
+        }
     }
 
     bool visit(TypeId ty) override
@@ -123,23 +141,23 @@ struct PromoteTypeLevels final : TypeOnceVisitor
     }
 };
 
-static void promoteTypeLevels(TxnLog& log, const TypeArena* typeArena, TypeLevel minLevel, TypeId ty)
+static void promoteTypeLevels(TxnLog& log, const TypeArena* typeArena, TypeLevel minLevel, Scope* outerScope, bool useScopes, TypeId ty)
 {
     // Type levels of types from other modules are already global, so we don't need to promote anything inside
     if (ty->owningArena != typeArena)
         return;
 
-    PromoteTypeLevels ptl{log, typeArena, minLevel};
+    PromoteTypeLevels ptl{log, typeArena, minLevel, outerScope, useScopes};
     ptl.traverse(ty);
 }
 
-void promoteTypeLevels(TxnLog& log, const TypeArena* typeArena, TypeLevel minLevel, TypePackId tp)
+void promoteTypeLevels(TxnLog& log, const TypeArena* typeArena, TypeLevel minLevel, Scope* outerScope, bool useScopes, TypePackId tp)
 {
     // Type levels of types from other modules are already global, so we don't need to promote anything inside
     if (tp->owningArena != typeArena)
         return;
 
-    PromoteTypeLevels ptl{log, typeArena, minLevel};
+    PromoteTypeLevels ptl{log, typeArena, minLevel, outerScope, useScopes};
     ptl.traverse(tp);
 }
 
@@ -352,9 +370,12 @@ static std::optional<std::pair<Luau::Name, const SingletonType*>> getTableMatchT
 }
 
 template<typename TY_A, typename TY_B>
-static bool subsumes(TY_A* left, TY_B* right)
+static bool subsumes(bool useScopes, TY_A* left, TY_B* right)
 {
-    return left->level.subsumes(right->level);
+    if (useScopes)
+        return subsumes(left->scope, right->scope);
+    else
+        return left->level.subsumes(right->level);
 }
 
 TypeMismatch::Context Unifier::mismatchContext()
@@ -443,7 +464,7 @@ void Unifier::tryUnify_(TypeId subTy, TypeId superTy, bool isFunctionCall, bool
     auto superFree = log.getMutable<FreeType>(superTy);
     auto subFree = log.getMutable<FreeType>(subTy);
 
-    if (superFree && subFree && subsumes(superFree, subFree))
+    if (superFree && subFree && subsumes(useNewSolver, superFree, subFree))
     {
         if (!occursCheck(subTy, superTy, /* reversed = */ false))
             log.replace(subTy, BoundType(superTy));
@@ -454,7 +475,7 @@ void Unifier::tryUnify_(TypeId subTy, TypeId superTy, bool isFunctionCall, bool
     {
         if (!occursCheck(superTy, subTy, /* reversed = */ true))
         {
-            if (subsumes(superFree, subFree))
+            if (subsumes(useNewSolver, superFree, subFree))
             {
                 log.changeLevel(subTy, superFree->level);
             }
@@ -468,7 +489,7 @@ void Unifier::tryUnify_(TypeId subTy, TypeId superTy, bool isFunctionCall, bool
     {
         // Unification can't change the level of a generic.
         auto subGeneric = log.getMutable<GenericType>(subTy);
-        if (subGeneric && !subsumes(subGeneric, superFree))
+        if (subGeneric && !subsumes(useNewSolver, subGeneric, superFree))
         {
             // TODO: a more informative error message? CLI-39912
             reportError(location, GenericError{"Generic subtype escaping scope"});
@@ -477,7 +498,7 @@ void Unifier::tryUnify_(TypeId subTy, TypeId superTy, bool isFunctionCall, bool
 
         if (!occursCheck(superTy, subTy, /* reversed = */ true))
         {
-            promoteTypeLevels(log, types, superFree->level, subTy);
+            promoteTypeLevels(log, types, superFree->level, superFree->scope, useNewSolver, subTy);
 
             Widen widen{types, builtinTypes};
             log.replace(superTy, BoundType(widen(subTy)));
@@ -494,7 +515,7 @@ void Unifier::tryUnify_(TypeId subTy, TypeId superTy, bool isFunctionCall, bool
 
         // Unification can't change the level of a generic.
         auto superGeneric = log.getMutable<GenericType>(superTy);
-        if (superGeneric && !subsumes(superGeneric, subFree))
+        if (superGeneric && !subsumes(useNewSolver, superGeneric, subFree))
         {
             // TODO: a more informative error message? CLI-39912
             reportError(location, GenericError{"Generic supertype escaping scope"});
@@ -503,7 +524,7 @@ void Unifier::tryUnify_(TypeId subTy, TypeId superTy, bool isFunctionCall, bool
 
         if (!occursCheck(subTy, superTy, /* reversed = */ false))
         {
-            promoteTypeLevels(log, types, subFree->level, superTy);
+            promoteTypeLevels(log, types, subFree->level, subFree->scope, useNewSolver, superTy);
             log.replace(subTy, BoundType(superTy));
         }
 
@@ -515,7 +536,7 @@ void Unifier::tryUnify_(TypeId subTy, TypeId superTy, bool isFunctionCall, bool
         auto superGeneric = log.getMutable<GenericType>(superTy);
         auto subGeneric = log.getMutable<GenericType>(subTy);
 
-        if (superGeneric && subGeneric && subsumes(superGeneric, subGeneric))
+        if (superGeneric && subGeneric && subsumes(useNewSolver, superGeneric, subGeneric))
         {
             if (!occursCheck(subTy, superTy, /* reversed = */ false))
                 log.replace(subTy, BoundType(superTy));
@@ -732,6 +753,9 @@ void Unifier::tryUnifyUnionWithType(TypeId subTy, const UnionType* subUnion, Typ
         std::unique_ptr<Unifier> innerState = makeChildUnifier();
         innerState->tryUnify_(type, superTy);
 
+        if (useNewSolver)
+            logs.push_back(std::move(innerState->log));
+
         if (auto e = hasUnificationTooComplex(innerState->errors))
             unificationTooComplex = e;
         else if (innerState->failure)
@@ -846,8 +870,13 @@ void Unifier::tryUnifyTypeWithUnion(TypeId subTy, TypeId superTy, const UnionTyp
         if (!innerState->failure)
         {
             found = true;
-            log.concat(std::move(innerState->log));
-            break;
+            if (useNewSolver)
+                logs.push_back(std::move(innerState->log));
+            else
+            {
+                log.concat(std::move(innerState->log));
+                break;
+            }
         }
         else if (innerState->errors.empty())
         {
@@ -866,6 +895,9 @@ void Unifier::tryUnifyTypeWithUnion(TypeId subTy, TypeId superTy, const UnionTyp
         }
     }
 
+    if (useNewSolver)
+        log.concatAsUnion(combineLogsIntoUnion(std::move(logs)), NotNull{types});
+
     if (unificationTooComplex)
     {
         reportError(*unificationTooComplex);
@@ -943,10 +975,16 @@ void Unifier::tryUnifyTypeWithIntersection(TypeId subTy, TypeId superTy, const I
                 firstFailedOption = {innerState->errors.front()};
         }
 
-        log.concat(std::move(innerState->log));
+        if (useNewSolver)
+            logs.push_back(std::move(innerState->log));
+        else
+            log.concat(std::move(innerState->log));
         failure |= innerState->failure;
     }
 
+    if (useNewSolver)
+        log.concat(combineLogsIntoIntersection(std::move(logs)));
+
     if (unificationTooComplex)
         reportError(*unificationTooComplex);
     else if (firstFailedOption)
@@ -994,6 +1032,28 @@ void Unifier::tryUnifyIntersectionWithType(TypeId subTy, const IntersectionType*
         }
     }
 
+    if (useNewSolver && normalize)
+    {
+        // Sometimes a negation type is inside one of the types, e.g. { p: number } & { p: ~number }.
+        NegationTypeFinder finder;
+        finder.traverse(subTy);
+
+        if (finder.found)
+        {
+            // It is possible that A & B <: T even though A </: T and B </: T
+            // for example (string?) & ~nil <: string.
+            // We deal with this by type normalization.
+            std::shared_ptr<const NormalizedType> subNorm = normalizer->normalize(subTy);
+            std::shared_ptr<const NormalizedType> superNorm = normalizer->normalize(superTy);
+            if (subNorm && superNorm)
+                tryUnifyNormalizedTypes(subTy, superTy, *subNorm, *superNorm, "none of the intersection parts are compatible");
+            else
+                reportError(location, NormalizationTooComplex{});
+
+            return;
+        }
+    }
+
     std::vector<TxnLog> logs;
 
     for (size_t i = 0; i < uv->parts.size(); ++i)
@@ -1010,7 +1070,7 @@ void Unifier::tryUnifyIntersectionWithType(TypeId subTy, const IntersectionType*
         {
             found = true;
             errorsSuppressed = innerState->failure;
-            if (innerState->failure)
+            if (useNewSolver || innerState->failure)
                 logs.push_back(std::move(innerState->log));
             else
             {
@@ -1025,7 +1085,9 @@ void Unifier::tryUnifyIntersectionWithType(TypeId subTy, const IntersectionType*
         }
     }
 
-    if (errorsSuppressed)
+    if (useNewSolver)
+        log.concat(combineLogsIntoIntersection(std::move(logs)));
+    else if (errorsSuppressed)
         log.concat(std::move(logs.front()));
 
     if (unificationTooComplex)
@@ -1139,6 +1201,24 @@ void Unifier::tryUnifyNormalizedTypes(
             }
         }
 
+        if (useNewSolver)
+        {
+            for (TypeId superTable : superNorm.tables)
+            {
+                std::unique_ptr<Unifier> innerState = makeChildUnifier();
+                innerState->tryUnify(subClass, superTable);
+
+                if (innerState->errors.empty())
+                {
+                    found = true;
+                    log.concat(std::move(innerState->log));
+                    break;
+                }
+                else if (auto e = hasUnificationTooComplex(innerState->errors))
+                    return reportError(*e);
+            }
+        }
+
         if (!found)
         {
             return reportError(location, TypeMismatch{superTy, subTy, reason, error, mismatchContext()});
@@ -1423,6 +1503,12 @@ struct WeirdIter
     }
 };
 
+void Unifier::enableNewSolver()
+{
+    useNewSolver = true;
+    log.useScopes = true;
+}
+
 ErrorVec Unifier::canUnify(TypeId subTy, TypeId superTy)
 {
     std::unique_ptr<Unifier> s = makeChildUnifier();
@@ -1502,6 +1588,8 @@ void Unifier::tryUnify_(TypePackId subTp, TypePackId superTp, bool isFunctionCal
         if (!occursCheck(superTp, subTp, /* reversed = */ true))
         {
             Widen widen{types, builtinTypes};
+            if (useNewSolver)
+                promoteTypeLevels(log, types, superFree->level, superFree->scope, /*useScopes*/ true, subTp);
             log.replace(superTp, Unifiable::Bound<TypePackId>(widen(subTp)));
         }
     }
@@ -1509,6 +1597,8 @@ void Unifier::tryUnify_(TypePackId subTp, TypePackId superTp, bool isFunctionCal
     {
         if (!occursCheck(subTp, superTp, /* reversed = */ false))
         {
+            if (useNewSolver)
+                promoteTypeLevels(log, types, subFree->level, subFree->scope, /*useScopes*/ true, superTp);
             log.replace(subTp, Unifiable::Bound<TypePackId>(superTp));
         }
     }
@@ -1598,28 +1688,74 @@ void Unifier::tryUnify_(TypePackId subTp, TypePackId superTp, bool isFunctionCal
             // If both are at the end, we're done
             if (!superIter.good() && !subIter.good())
             {
-                const bool lFreeTail = superTpv->tail && log.getMutable<FreeTypePack>(log.follow(*superTpv->tail)) != nullptr;
-                const bool rFreeTail = subTpv->tail && log.getMutable<FreeTypePack>(log.follow(*subTpv->tail)) != nullptr;
-                if (lFreeTail && rFreeTail)
+                if (useNewSolver)
                 {
-                    tryUnify_(*subTpv->tail, *superTpv->tail);
-                }
-                else if (lFreeTail)
-                {
-                    tryUnify_(emptyTp, *superTpv->tail);
-                }
-                else if (rFreeTail)
-                {
-                    tryUnify_(emptyTp, *subTpv->tail);
-                }
-                else if (subTpv->tail && superTpv->tail)
-                {
-                    if (log.getMutable<VariadicTypePack>(superIter.packId))
-                        tryUnifyVariadics(subIter.packId, superIter.packId, false, int(subIter.index));
-                    else if (log.getMutable<VariadicTypePack>(subIter.packId))
-                        tryUnifyVariadics(superIter.packId, subIter.packId, true, int(superIter.index));
+                    if (subIter.tail() && superIter.tail())
+                        tryUnify_(*subIter.tail(), *superIter.tail());
+                    else if (subIter.tail())
+                    {
+                        const TypePackId subTail = log.follow(*subIter.tail());
+
+                        if (log.get<FreeTypePack>(subTail))
+                            tryUnify_(subTail, emptyTp);
+                        else if (log.get<GenericTypePack>(subTail))
+                            reportError(location, TypePackMismatch{subTail, emptyTp});
+                        else if (log.get<VariadicTypePack>(subTail) || log.get<ErrorTypePack>(subTail))
+                        {
+                            // Nothing.  This is ok.
+                        }
+                        else
+                        {
+                            ice("Unexpected subtype tail pack " + toString(subTail), location);
+                        }
+                    }
+                    else if (superIter.tail())
+                    {
+                        const TypePackId superTail = log.follow(*superIter.tail());
+
+                        if (log.get<FreeTypePack>(superTail))
+                            tryUnify_(emptyTp, superTail);
+                        else if (log.get<GenericTypePack>(superTail))
+                            reportError(location, TypePackMismatch{emptyTp, superTail});
+                        else if (log.get<VariadicTypePack>(superTail) || log.get<ErrorTypePack>(superTail))
+                        {
+                            // Nothing.  This is ok.
+                        }
+                        else
+                        {
+                            ice("Unexpected supertype tail pack " + toString(superTail), location);
+                        }
+                    }
                     else
+                    {
+                        // Nothing.  This is ok.
+                    }
+                }
+                else
+                {
+                    const bool lFreeTail = superTpv->tail && log.getMutable<FreeTypePack>(log.follow(*superTpv->tail)) != nullptr;
+                    const bool rFreeTail = subTpv->tail && log.getMutable<FreeTypePack>(log.follow(*subTpv->tail)) != nullptr;
+                    if (lFreeTail && rFreeTail)
+                    {
                         tryUnify_(*subTpv->tail, *superTpv->tail);
+                    }
+                    else if (lFreeTail)
+                    {
+                        tryUnify_(emptyTp, *superTpv->tail);
+                    }
+                    else if (rFreeTail)
+                    {
+                        tryUnify_(emptyTp, *subTpv->tail);
+                    }
+                    else if (subTpv->tail && superTpv->tail)
+                    {
+                        if (log.getMutable<VariadicTypePack>(superIter.packId))
+                            tryUnifyVariadics(subIter.packId, superIter.packId, false, int(subIter.index));
+                        else if (log.getMutable<VariadicTypePack>(subIter.packId))
+                            tryUnifyVariadics(superIter.packId, subIter.packId, true, int(superIter.index));
+                        else
+                            tryUnify_(*subTpv->tail, *superTpv->tail);
+                    }
                 }
 
                 break;
@@ -2076,7 +2212,7 @@ void Unifier::tryUnifyTables(TypeId subTy, TypeId superTy, bool isIntersection,
                 variance = Invariant;
 
             std::unique_ptr<Unifier> innerState = makeChildUnifier();
-            if (FFlag::LuauFixIndexerSubtypingOrdering)
+            if (useNewSolver || FFlag::LuauFixIndexerSubtypingOrdering)
                 innerState->tryUnify_(prop.type(), superTable->indexer->indexResultType);
             else
             {
@@ -2361,8 +2497,49 @@ void Unifier::tryUnifyWithMetatable(TypeId subTy, TypeId superTy, bool reversed)
         {
         case TableState::Free:
         {
-            tryUnify_(subTy, superMetatable->table);
-            log.bindTable(subTy, superTy);
+            if (useNewSolver)
+            {
+                std::unique_ptr<Unifier> innerState = makeChildUnifier();
+                bool missingProperty = false;
+
+                for (const auto& [propName, prop] : subTable->props)
+                {
+                    if (std::optional<TypeId> mtPropTy = findTablePropertyRespectingMeta(superTy, propName))
+                    {
+                        innerState->tryUnify(prop.type(), *mtPropTy);
+                    }
+                    else
+                    {
+                        reportError(mismatchError);
+                        missingProperty = true;
+                        break;
+                    }
+                }
+
+                if (const TableType* superTable = log.get<TableType>(log.follow(superMetatable->table)))
+                {
+                    // TODO: Unify indexers.
+                }
+
+                if (auto e = hasUnificationTooComplex(innerState->errors))
+                    reportError(*e);
+                else if (!innerState->errors.empty())
+                    reportError(TypeError{
+                        location,
+                        TypeMismatch{reversed ? subTy : superTy, reversed ? superTy : subTy, "", innerState->errors.front(), mismatchContext()}
+                    });
+                else if (!missingProperty)
+                {
+                    log.concat(std::move(innerState->log));
+                    log.bindTable(subTy, superTy);
+                    failure |= innerState->failure;
+                }
+            }
+            else
+            {
+                tryUnify_(subTy, superMetatable->table);
+                log.bindTable(subTy, superTy);
+            }
 
             break;
         }
@@ -2688,9 +2865,18 @@ std::optional<TypeId> Unifier::findTablePropertyRespectingMeta(TypeId lhsType, N
     return Luau::findTablePropertyRespectingMeta(builtinTypes, errors, lhsType, name, location);
 }
 
+TxnLog Unifier::combineLogsIntoIntersection(std::vector<TxnLog> logs)
+{
+    LUAU_ASSERT(useNewSolver);
+    TxnLog result(useNewSolver);
+    for (TxnLog& log : logs)
+        result.concatAsIntersections(std::move(log), NotNull{types});
+    return result;
+}
+
 TxnLog Unifier::combineLogsIntoUnion(std::vector<TxnLog> logs)
 {
-    TxnLog result;
+    TxnLog result(useNewSolver);
     for (TxnLog& log : logs)
         result.concatAsUnion(std::move(log), NotNull{types});
     return result;
@@ -2835,6 +3021,9 @@ std::unique_ptr<Unifier> Unifier::makeChildUnifier()
     u->normalize = normalize;
     u->checkInhabited = checkInhabited;
 
+    if (useNewSolver)
+        u->enableNewSolver();
+
     return u;
 }
 

Analysis/src/Unifier2.cpp

@@ -18,8 +18,6 @@
 #include <optional>
 
 LUAU_FASTINT(LuauTypeInferRecursionLimit)
-LUAU_FASTFLAGVARIABLE(LuauUnifyMetatableWithAny)
-LUAU_FASTFLAG(LuauExtraFollows)
 
 namespace Luau
 {
@@ -237,10 +235,6 @@ bool Unifier2::unify(TypeId subTy, TypeId superTy)
     auto superMetatable = get<MetatableType>(superTy);
     if (subMetatable && superMetatable)
         return unify(subMetatable, superMetatable);
-    else if (FFlag::LuauUnifyMetatableWithAny && subMetatable && superAny)
-        return unify(subMetatable, superAny);
-    else if (FFlag::LuauUnifyMetatableWithAny && subAny && superMetatable)
-        return unify(subAny, superMetatable);
     else if (subMetatable) // if we only have one metatable, unify with the inner table
         return unify(subMetatable->table, superTy);
     else if (superMetatable) // if we only have one metatable, unify with the inner table
@@ -283,7 +277,7 @@ bool Unifier2::unifyFreeWithType(TypeId subTy, TypeId superTy)
     if (superArgTail)
         return doDefault();
 
-    const IntersectionType* upperBoundIntersection = get<IntersectionType>(FFlag::LuauExtraFollows ? upperBound : subFree->upperBound);
+    const IntersectionType* upperBoundIntersection = get<IntersectionType>(subFree->upperBound);
     if (!upperBoundIntersection)
         return doDefault();
 
@@ -530,16 +524,6 @@ bool Unifier2::unify(const TableType* subTable, const AnyType* superAny)
     return true;
 }
 
-bool Unifier2::unify(const MetatableType* subMetatable, const AnyType*)
-{
-    return unify(subMetatable->metatable, builtinTypes->anyType) && unify(subMetatable->table, builtinTypes->anyType);
-}
-
-bool Unifier2::unify(const AnyType*, const MetatableType* superMetatable)
-{
-    return unify(builtinTypes->anyType, superMetatable->metatable) && unify(builtinTypes->anyType, superMetatable->table);
-}
-
 // FIXME?  This should probably return an ErrorVec or an optional<TypeError>
 // rather than a boolean to signal an occurs check failure.
 bool Unifier2::unify(TypePackId subTp, TypePackId superTp)
@@ -650,33 +634,38 @@ struct FreeTypeSearcher : TypeVisitor
     {
     }
 
-    Polarity polarity = Polarity::Positive;
+    enum Polarity
+    {
+        Positive,
+        Negative,
+        Both,
+    };
+
+    Polarity polarity = Positive;
 
     void flip()
     {
         switch (polarity)
         {
-        case Polarity::Positive:
-            polarity = Polarity::Negative;
+        case Positive:
+            polarity = Negative;
             break;
-        case Polarity::Negative:
-            polarity = Polarity::Positive;
+        case Negative:
+            polarity = Positive;
             break;
-        case Polarity::Mixed:
+        case Both:
             break;
-        default:
-            LUAU_ASSERT(!"Unreachable");
         }
     }
 
     DenseHashSet<const void*> seenPositive{nullptr};
     DenseHashSet<const void*> seenNegative{nullptr};
 
-    bool seenWithCurrentPolarity(const void* ty)
+    bool seenWithPolarity(const void* ty)
     {
         switch (polarity)
         {
-        case Polarity::Positive:
+        case Positive:
         {
             if (seenPositive.contains(ty))
                 return true;
@@ -684,7 +673,7 @@ struct FreeTypeSearcher : TypeVisitor
             seenPositive.insert(ty);
             return false;
         }
-        case Polarity::Negative:
+        case Negative:
         {
             if (seenNegative.contains(ty))
                 return true;
@@ -692,7 +681,7 @@ struct FreeTypeSearcher : TypeVisitor
             seenNegative.insert(ty);
             return false;
         }
-        case Polarity::Mixed:
+        case Both:
         {
             if (seenPositive.contains(ty) && seenNegative.contains(ty))
                 return true;
@@ -701,8 +690,6 @@ struct FreeTypeSearcher : TypeVisitor
             seenNegative.insert(ty);
             return false;
         }
-        default:
-            LUAU_ASSERT(!"Unreachable");
         }
 
         return false;
@@ -716,7 +703,7 @@ struct FreeTypeSearcher : TypeVisitor
 
     bool visit(TypeId ty) override
     {
-        if (seenWithCurrentPolarity(ty))
+        if (seenWithPolarity(ty))
             return false;
 
         LUAU_ASSERT(ty);
@@ -725,7 +712,7 @@ struct FreeTypeSearcher : TypeVisitor
 
     bool visit(TypeId ty, const FreeType& ft) override
     {
-        if (seenWithCurrentPolarity(ty))
+        if (seenWithPolarity(ty))
             return false;
 
         if (!subsumes(scope, ft.scope))
@@ -733,18 +720,16 @@ struct FreeTypeSearcher : TypeVisitor
 
         switch (polarity)
         {
-        case Polarity::Positive:
+        case Positive:
             positiveTypes[ty]++;
             break;
-        case Polarity::Negative:
+        case Negative:
             negativeTypes[ty]++;
             break;
-        case Polarity::Mixed:
+        case Both:
             positiveTypes[ty]++;
             negativeTypes[ty]++;
             break;
-        default:
-            LUAU_ASSERT(!"Unreachable");
         }
 
         return true;
@@ -752,25 +737,23 @@ struct FreeTypeSearcher : TypeVisitor
 
     bool visit(TypeId ty, const TableType& tt) override
     {
-        if (seenWithCurrentPolarity(ty))
+        if (seenWithPolarity(ty))
             return false;
 
         if ((tt.state == TableState::Free || tt.state == TableState::Unsealed) && subsumes(scope, tt.scope))
         {
             switch (polarity)
             {
-            case Polarity::Positive:
+            case Positive:
                 positiveTypes[ty]++;
                 break;
-            case Polarity::Negative:
+            case Negative:
                 negativeTypes[ty]++;
                 break;
-            case Polarity::Mixed:
+            case Both:
                 positiveTypes[ty]++;
                 negativeTypes[ty]++;
                 break;
-            default:
-                LUAU_ASSERT(!"Unreachable");
             }
         }
 
@@ -783,7 +766,7 @@ struct FreeTypeSearcher : TypeVisitor
                 LUAU_ASSERT(prop.isShared());
 
                 Polarity p = polarity;
-                polarity = Polarity::Mixed;
+                polarity = Both;
                 traverse(prop.type());
                 polarity = p;
             }
@@ -800,7 +783,7 @@ struct FreeTypeSearcher : TypeVisitor
 
     bool visit(TypeId ty, const FunctionType& ft) override
     {
-        if (seenWithCurrentPolarity(ty))
+        if (seenWithPolarity(ty))
             return false;
 
         flip();
@@ -819,7 +802,7 @@ struct FreeTypeSearcher : TypeVisitor
 
     bool visit(TypePackId tp, const FreeTypePack& ftp) override
     {
-        if (seenWithCurrentPolarity(tp))
+        if (seenWithPolarity(tp))
             return false;
 
         if (!subsumes(scope, ftp.scope))
@@ -827,18 +810,16 @@ struct FreeTypeSearcher : TypeVisitor
 
         switch (polarity)
         {
-        case Polarity::Positive:
+        case Positive:
             positiveTypes[tp]++;
             break;
-        case Polarity::Negative:
+        case Negative:
             negativeTypes[tp]++;
             break;
-        case Polarity::Mixed:
+        case Both:
             positiveTypes[tp]++;
             negativeTypes[tp]++;
             break;
-        default:
-            LUAU_ASSERT(!"Unreachable");
         }
 
         return true;

Ast/include/Luau/Ast.h

@@ -194,7 +194,6 @@ public:
     {
         Checked,
         Native,
-        Deprecated,
     };
 
     AstAttr(const Location& location, Type type);
@@ -454,7 +453,6 @@ public:
     void visit(AstVisitor* visitor) override;
 
     bool hasNativeAttribute() const;
-    bool hasAttribute(AstAttr::Type attributeType) const;
 
     AstArray<AstAttr*> attributes;
     AstArray<AstGenericType*> generics;
@@ -892,22 +890,14 @@ class AstStatTypeFunction : public AstStat
 public:
     LUAU_RTTI(AstStatTypeFunction);
 
-    AstStatTypeFunction(
-        const Location& location,
-        const AstName& name,
-        const Location& nameLocation,
-        AstExprFunction* body,
-        bool exported,
-        bool hasErrors
-    );
+    AstStatTypeFunction(const Location& location, const AstName& name, const Location& nameLocation, AstExprFunction* body, bool exported);
 
     void visit(AstVisitor* visitor) override;
 
     AstName name;
     Location nameLocation;
-    AstExprFunction* body = nullptr;
-    bool exported = false;
-    bool hasErrors = false;
+    AstExprFunction* body;
+    bool exported;
 };
 
 class AstStatDeclareGlobal : public AstStat
@@ -960,7 +950,6 @@ public:
     void visit(AstVisitor* visitor) override;
 
     bool isCheckedFunction() const;
-    bool hasAttribute(AstAttr::Type attributeType) const;
 
     AstArray<AstAttr*> attributes;
     AstName name;
@@ -1117,7 +1106,6 @@ public:
     void visit(AstVisitor* visitor) override;
 
     bool isCheckedFunction() const;
-    bool hasAttribute(AstAttr::Type attributeType) const;
 
     AstArray<AstAttr*> attributes;
     AstArray<AstGenericType*> generics;
@@ -1139,16 +1127,6 @@ public:
     AstExpr* expr;
 };
 
-class AstTypeOptional : public AstType
-{
-public:
-    LUAU_RTTI(AstTypeOptional)
-
-    AstTypeOptional(const Location& location);
-
-    void visit(AstVisitor* visitor) override;
-};
-
 class AstTypeUnion : public AstType
 {
 public:
@@ -1471,10 +1449,6 @@ public:
     {
         return visit(static_cast<AstStat*>(node));
     }
-    virtual bool visit(class AstStatTypeFunction* node)
-    {
-        return visit(static_cast<AstStat*>(node));
-    }
     virtual bool visit(class AstStatDeclareFunction* node)
     {
         return visit(static_cast<AstStat*>(node));
@@ -1514,10 +1488,6 @@ public:
     {
         return visit(static_cast<AstType*>(node));
     }
-    virtual bool visit(class AstTypeOptional* node)
-    {
-        return visit(static_cast<AstType*>(node));
-    }
     virtual bool visit(class AstTypeUnion* node)
     {
         return visit(static_cast<AstType*>(node));

Ast/include/Luau/Cst.h

@@ -105,21 +105,6 @@ public:
     Position closeBracketPosition;
 };
 
-class CstExprFunction : public CstNode
-{
-public:
-    LUAU_CST_RTTI(CstExprFunction)
-
-    CstExprFunction();
-
-    Position functionKeywordPosition{0, 0};
-    Position openGenericsPosition{0,0};
-    AstArray<Position> genericsCommaPositions;
-    Position closeGenericsPosition{0,0};
-    AstArray<Position> argsCommaPositions;
-    Position returnSpecifierPosition{0,0};
-};
-
 class CstExprTable : public CstNode
 {
 public:
@@ -275,24 +260,13 @@ public:
     Position opPosition;
 };
 
-class CstStatFunction : public CstNode
-{
-public:
-    LUAU_CST_RTTI(CstStatFunction)
-
-    explicit CstStatFunction(Position functionKeywordPosition);
-
-    Position functionKeywordPosition;
-};
-
 class CstStatLocalFunction : public CstNode
 {
 public:
     LUAU_CST_RTTI(CstStatLocalFunction)
 
-    explicit CstStatLocalFunction(Position localKeywordPosition, Position functionKeywordPosition);
+    explicit CstStatLocalFunction(Position functionKeywordPosition);
 
-    Position localKeywordPosition;
     Position functionKeywordPosition;
 };
 
@@ -337,17 +311,6 @@ public:
     Position equalsPosition;
 };
 
-class CstStatTypeFunction : public CstNode
-{
-public:
-    LUAU_CST_RTTI(CstStatTypeFunction)
-
-    CstStatTypeFunction(Position typeKeywordPosition, Position functionKeywordPosition);
-
-    Position typeKeywordPosition;
-    Position functionKeywordPosition;
-};
-
 class CstTypeReference : public CstNode
 {
 public:
@@ -396,32 +359,6 @@ public:
     bool isArray = false;
 };
 
-class CstTypeFunction : public CstNode
-{
-public:
-    LUAU_CST_RTTI(CstTypeFunction)
-
-    CstTypeFunction(
-        Position openGenericsPosition,
-        AstArray<Position> genericsCommaPositions,
-        Position closeGenericsPosition,
-        Position openArgsPosition,
-        AstArray<std::optional<Position>> argumentNameColonPositions,
-        AstArray<Position> argumentsCommaPositions,
-        Position closeArgsPosition,
-        Position returnArrowPosition
-    );
-
-    Position openGenericsPosition;
-    AstArray<Position> genericsCommaPositions;
-    Position closeGenericsPosition;
-    Position openArgsPosition;
-    AstArray<std::optional<Position>> argumentNameColonPositions;
-    AstArray<Position> argumentsCommaPositions;
-    Position closeArgsPosition;
-    Position returnArrowPosition;
-};
-
 class CstTypeTypeof : public CstNode
 {
 public:
@@ -433,28 +370,6 @@ public:
     Position closePosition;
 };
 
-class CstTypeUnion : public CstNode
-{
-public:
-    LUAU_CST_RTTI(CstTypeUnion)
-
-    CstTypeUnion(std::optional<Position> leadingPosition, AstArray<Position> separatorPositions);
-
-    std::optional<Position> leadingPosition;
-    AstArray<Position> separatorPositions;
-};
-
-class CstTypeIntersection : public CstNode
-{
-public:
-    LUAU_CST_RTTI(CstTypeIntersection)
-
-    explicit CstTypeIntersection(std::optional<Position> leadingPosition, AstArray<Position> separatorPositions);
-
-    std::optional<Position> leadingPosition;
-    AstArray<Position> separatorPositions;
-};
-
 class CstTypeSingletonString : public CstNode
 {
 public:
@@ -467,26 +382,4 @@ public:
     unsigned int blockDepth;
 };
 
-class CstTypePackExplicit : public CstNode
-{
-public:
-    LUAU_CST_RTTI(CstTypePackExplicit)
-
-    CstTypePackExplicit(Position openParenthesesPosition, Position closeParenthesesPosition, AstArray<Position> commaPositions);
-
-    Position openParenthesesPosition;
-    Position closeParenthesesPosition;
-    AstArray<Position> commaPositions;
-};
-
-class CstTypePackGeneric : public CstNode
-{
-public:
-    LUAU_CST_RTTI(CstTypePackGeneric)
-
-    explicit CstTypePackGeneric(Position ellipsisPosition);
-
-    Position ellipsisPosition;
-};
-
 } // namespace Luau

Ast/include/Luau/Lexer.h

@@ -187,11 +187,6 @@ public:
     static bool fixupQuotedString(std::string& data);
     static void fixupMultilineString(std::string& data);
 
-    unsigned int getOffset() const
-    {
-        return offset;
-    }
-
 private:
     char peekch() const;
     char peekch(unsigned int lookahead) const;

Ast/include/Luau/ParseResult.h

@@ -71,19 +71,6 @@ struct ParseResult
     CstNodeMap cstNodeMap{nullptr};
 };
 
-struct ParseExprResult
-{
-    AstExpr* expr;
-    size_t lines = 0;
-
-    std::vector<HotComment> hotcomments;
-    std::vector<ParseError> errors;
-
-    std::vector<Comment> commentLocations;
-
-    CstNodeMap cstNodeMap{nullptr};
-};
-
 static constexpr const char* kParseNameError = "%error-id%";
 
 } // namespace Luau

Ast/include/Luau/Parser.h

@@ -63,14 +63,6 @@ public:
         ParseOptions options = ParseOptions()
     );
 
-    static ParseExprResult parseExpr(
-        const char* buffer,
-        std::size_t bufferSize,
-        AstNameTable& names,
-        Allocator& allocator,
-        ParseOptions options = ParseOptions()
-    );
-
 private:
     struct Name;
     struct Binding;
@@ -125,7 +117,7 @@ private:
     AstStat* parseFor();
 
     // funcname ::= Name {`.' Name} [`:' Name]
-    AstExpr* parseFunctionName(bool& hasself, AstName& debugname);
+    AstExpr* parseFunctionName(Location start_DEPRECATED, bool& hasself, AstName& debugname);
 
     // function funcname funcbody
     LUAU_FORCEINLINE AstStat* parseFunctionStat(const AstArray<AstAttr*>& attributes = {nullptr, 0});
@@ -155,11 +147,9 @@ private:
     AstStat* parseTypeAlias(const Location& start, bool exported, Position typeKeywordPosition);
 
     // type function Name ... end
-    AstStat* parseTypeFunction(const Location& start, bool exported, Position typeKeywordPosition);
-
-    AstDeclaredClassProp parseDeclaredClassMethod(const AstArray<AstAttr*>& attributes);
-    AstDeclaredClassProp parseDeclaredClassMethod_DEPRECATED();
+    AstStat* parseTypeFunction(const Location& start, bool exported);
 
+    AstDeclaredClassProp parseDeclaredClassMethod();
 
     // `declare global' Name: Type |
     // `declare function' Name`(' [parlist] `)' [`:` Type]
@@ -194,8 +184,7 @@ private:
     std::tuple<bool, Location, AstTypePack*> parseBindingList(
         TempVector<Binding>& result,
         bool allowDot3 = false,
-        AstArray<Position>* commaPositions = nullptr,
-        std::optional<Position> initialCommaPosition = std::nullopt
+        TempVector<Position>* commaPositions = nullptr
     );
 
     AstType* parseOptionalType();
@@ -212,14 +201,9 @@ private:
     //      |   `(' [TypeList] `)' `->` ReturnType
 
     // Returns the variadic annotation, if it exists.
-    AstTypePack* parseTypeList(
-        TempVector<AstType*>& result,
-        TempVector<std::optional<AstArgumentName>>& resultNames,
-        TempVector<Position>* commaPositions = nullptr,
-        TempVector<std::optional<Position>>* nameColonPositions = nullptr
-    );
+    AstTypePack* parseTypeList(TempVector<AstType*>& result, TempVector<std::optional<AstArgumentName>>& resultNames);
 
-    std::optional<AstTypeList> parseOptionalReturnType(Position* returnSpecifierPosition = nullptr);
+    std::optional<AstTypeList> parseOptionalReturnType();
     std::pair<Location, AstTypeList> parseReturnType();
 
     struct TableIndexerResult
@@ -230,9 +214,9 @@ private:
         Position colonPosition;
     };
 
-    TableIndexerResult parseTableIndexer(AstTableAccess access, std::optional<Location> accessLocation, Lexeme begin);
-    // Remove with FFlagLuauStoreCSTData2
-    AstTableIndexer* parseTableIndexer_DEPRECATED(AstTableAccess access, std::optional<Location> accessLocation, Lexeme begin);
+    TableIndexerResult parseTableIndexer(AstTableAccess access, std::optional<Location> accessLocation);
+    // Remove with FFlagLuauStoreCSTData
+    AstTableIndexer* parseTableIndexer_DEPRECATED(AstTableAccess access, std::optional<Location> accessLocation);
 
     AstTypeOrPack parseFunctionType(bool allowPack, const AstArray<AstAttr*>& attributes);
     AstType* parseFunctionTypeTail(
@@ -313,7 +297,7 @@ private:
     std::pair<AstArray<AstGenericType*>, AstArray<AstGenericTypePack*>> parseGenericTypeList(
         bool withDefaultValues,
         Position* openPosition = nullptr,
-        AstArray<Position>* commaPositions = nullptr,
+        TempVector<Position>* commaPositions = nullptr,
         Position* closePosition = nullptr
     );
 
@@ -499,7 +483,6 @@ private:
     std::vector<AstGenericTypePack*> scratchGenericTypePacks;
     std::vector<std::optional<AstArgumentName>> scratchOptArgName;
     std::vector<Position> scratchPosition;
-    std::vector<std::optional<Position>> scratchOptPosition;
     std::string scratchData;
 
     CstNodeMap cstNodeMap;

Ast/src/Ast.cpp

@@ -3,24 +3,9 @@
 
 #include "Luau/Common.h"
 
-LUAU_FASTFLAG(LuauDeprecatedAttribute);
-
 namespace Luau
 {
 
-static bool hasAttributeInArray(const AstArray<AstAttr*> attributes, AstAttr::Type attributeType)
-{
-    LUAU_ASSERT(FFlag::LuauDeprecatedAttribute);
-
-    for (const auto attribute : attributes)
-    {
-        if (attribute->type == attributeType)
-            return true;
-    }
-
-    return false;
-}
-
 static void visitTypeList(AstVisitor* visitor, const AstTypeList& list)
 {
     for (AstType* ty : list.types)
@@ -292,13 +277,6 @@ bool AstExprFunction::hasNativeAttribute() const
     return false;
 }
 
-bool AstExprFunction::hasAttribute(const AstAttr::Type attributeType) const
-{
-    LUAU_ASSERT(FFlag::LuauDeprecatedAttribute);
-
-    return hasAttributeInArray(attributes, attributeType);
-}
-
 AstExprTable::AstExprTable(const Location& location, const AstArray<Item>& items)
     : AstExpr(ClassIndex(), location)
     , items(items)
@@ -813,15 +791,13 @@ AstStatTypeFunction::AstStatTypeFunction(
     const AstName& name,
     const Location& nameLocation,
     AstExprFunction* body,
-    bool exported,
-    bool hasErrors
+    bool exported
 )
     : AstStat(ClassIndex(), location)
     , name(name)
     , nameLocation(nameLocation)
     , body(body)
     , exported(exported)
-    , hasErrors(hasErrors)
 {
 }
 
@@ -918,13 +894,6 @@ bool AstStatDeclareFunction::isCheckedFunction() const
     return false;
 }
 
-bool AstStatDeclareFunction::hasAttribute(AstAttr::Type attributeType) const
-{
-    LUAU_ASSERT(FFlag::LuauDeprecatedAttribute);
-
-    return hasAttributeInArray(attributes, attributeType);
-}
-
 AstStatDeclareClass::AstStatDeclareClass(
     const Location& location,
     const AstName& name,
@@ -1088,13 +1057,6 @@ bool AstTypeFunction::isCheckedFunction() const
     return false;
 }
 
-bool AstTypeFunction::hasAttribute(AstAttr::Type attributeType) const
-{
-    LUAU_ASSERT(FFlag::LuauDeprecatedAttribute);
-
-    return hasAttributeInArray(attributes, attributeType);
-}
-
 AstTypeTypeof::AstTypeTypeof(const Location& location, AstExpr* expr)
     : AstType(ClassIndex(), location)
     , expr(expr)
@@ -1107,16 +1069,6 @@ void AstTypeTypeof::visit(AstVisitor* visitor)
         expr->visit(visitor);
 }
 
-AstTypeOptional::AstTypeOptional(const Location& location)
-    : AstType(ClassIndex(), location)
-{
-}
-
-void AstTypeOptional::visit(AstVisitor* visitor)
-{
-    visitor->visit(this);
-}
-
 AstTypeUnion::AstTypeUnion(const Location& location, const AstArray<AstType*>& types)
     : AstType(ClassIndex(), location)
     , types(types)

Ast/src/Cst.cpp

@@ -38,10 +38,6 @@ CstExprIndexExpr::CstExprIndexExpr(Position openBracketPosition, Position closeB
 {
 }
 
-CstExprFunction::CstExprFunction() : CstNode(CstClassIndex())
-{
-}
-
 CstExprTable::CstExprTable(const AstArray<Item>& items)
     : CstNode(CstClassIndex())
     , items(items)
@@ -129,19 +125,12 @@ CstStatCompoundAssign::CstStatCompoundAssign(Position opPosition)
 {
 }
 
-CstStatFunction::CstStatFunction(Position functionKeywordPosition)
+CstStatLocalFunction::CstStatLocalFunction(Position functionKeywordPosition)
     : CstNode(CstClassIndex())
     , functionKeywordPosition(functionKeywordPosition)
 {
 }
 
-CstStatLocalFunction::CstStatLocalFunction(Position localKeywordPosition, Position functionKeywordPosition)
-    : CstNode(CstClassIndex())
-    , localKeywordPosition(localKeywordPosition)
-    , functionKeywordPosition(functionKeywordPosition)
-{
-}
-
 CstGenericType::CstGenericType(std::optional<Position> defaultEqualsPosition)
     : CstNode(CstClassIndex())
     , defaultEqualsPosition(defaultEqualsPosition)
@@ -171,13 +160,6 @@ CstStatTypeAlias::CstStatTypeAlias(
 {
 }
 
-CstStatTypeFunction::CstStatTypeFunction(Position typeKeywordPosition, Position functionKeywordPosition)
-    : CstNode(CstClassIndex())
-    , typeKeywordPosition(typeKeywordPosition)
-    , functionKeywordPosition(functionKeywordPosition)
-{
-}
-
 CstTypeReference::CstTypeReference(
     std::optional<Position> prefixPointPosition,
     Position openParametersPosition,
@@ -199,28 +181,6 @@ CstTypeTable::CstTypeTable(AstArray<Item> items, bool isArray)
 {
 }
 
-CstTypeFunction::CstTypeFunction(
-    Position openGenericsPosition,
-    AstArray<Position> genericsCommaPositions,
-    Position closeGenericsPosition,
-    Position openArgsPosition,
-    AstArray<std::optional<Position>> argumentNameColonPositions,
-    AstArray<Position> argumentsCommaPositions,
-    Position closeArgsPosition,
-    Position returnArrowPosition
-)
-    : CstNode(CstClassIndex())
-    , openGenericsPosition(openGenericsPosition)
-    , genericsCommaPositions(genericsCommaPositions)
-    , closeGenericsPosition(closeGenericsPosition)
-    , openArgsPosition(openArgsPosition)
-    , argumentNameColonPositions(argumentNameColonPositions)
-    , argumentsCommaPositions(argumentsCommaPositions)
-    , closeArgsPosition(closeArgsPosition)
-    , returnArrowPosition(returnArrowPosition)
-{
-}
-
 CstTypeTypeof::CstTypeTypeof(Position openPosition, Position closePosition)
     : CstNode(CstClassIndex())
     , openPosition(openPosition)
@@ -228,20 +188,6 @@ CstTypeTypeof::CstTypeTypeof(Position openPosition, Position closePosition)
 {
 }
 
-CstTypeUnion::CstTypeUnion(std::optional<Position> leadingPosition, AstArray<Position> separatorPositions)
-    : CstNode(CstClassIndex())
-    , leadingPosition(leadingPosition)
-    , separatorPositions(separatorPositions)
-{
-}
-
-CstTypeIntersection::CstTypeIntersection(std::optional<Position> leadingPosition, AstArray<Position> separatorPositions)
-    : CstNode(CstClassIndex())
-    , leadingPosition(leadingPosition)
-    , separatorPositions(separatorPositions)
-{
-}
-
 CstTypeSingletonString::CstTypeSingletonString(AstArray<char> sourceString, CstExprConstantString::QuoteStyle quoteStyle, unsigned int blockDepth)
     : CstNode(CstClassIndex())
     , sourceString(sourceString)
@@ -251,18 +197,4 @@ CstTypeSingletonString::CstTypeSingletonString(AstArray<char> sourceString, CstE
     LUAU_ASSERT(quoteStyle != CstExprConstantString::QuotedInterp);
 }
 
-CstTypePackExplicit::CstTypePackExplicit(Position openParenthesesPosition, Position closeParenthesesPosition, AstArray<Position> commaPositions)
-    : CstNode(CstClassIndex())
-    , openParenthesesPosition(openParenthesesPosition)
-    , closeParenthesesPosition(closeParenthesesPosition)
-    , commaPositions(commaPositions)
-{
-}
-
-CstTypePackGeneric::CstTypePackGeneric(Position ellipsisPosition)
-    : CstNode(CstClassIndex())
-    , ellipsisPosition(ellipsisPosition)
-{
-}
-
 } // namespace Luau

Ast/src/Lexer.cpp

@@ -8,6 +8,9 @@
 
 #include <limits.h>
 
+LUAU_FASTFLAGVARIABLE(LexerResumesFromPosition2)
+LUAU_FASTFLAGVARIABLE(LexerFixInterpStringStart)
+
 namespace Luau
 {
 
@@ -339,9 +342,12 @@ Lexer::Lexer(const char* buffer, size_t bufferSize, AstNameTable& names, Positio
     : buffer(buffer)
     , bufferSize(bufferSize)
     , offset(0)
-    , line(startPosition.line)
-    , lineOffset(0u - startPosition.column)
-    , lexeme((Location(Position(startPosition.line, startPosition.column), 0)), Lexeme::Eof)
+    , line(FFlag::LexerResumesFromPosition2 ? startPosition.line : 0)
+    , lineOffset(FFlag::LexerResumesFromPosition2 ? 0u - startPosition.column : 0)
+    , lexeme(
+          (FFlag::LexerResumesFromPosition2 ? Location(Position(startPosition.line, startPosition.column), 0) : Location(Position(0, 0), 0)),
+          Lexeme::Eof
+      )
     , names(names)
     , skipComments(false)
     , readNames(true)
@@ -787,7 +793,7 @@ Lexeme Lexer::readNext()
             return Lexeme(Location(start, 1), '}');
         }
 
-        return readInterpolatedStringSection(start, Lexeme::InterpStringMid, Lexeme::InterpStringEnd);
+        return readInterpolatedStringSection(FFlag::LexerFixInterpStringStart ? start : position(), Lexeme::InterpStringMid, Lexeme::InterpStringEnd);
     }
 
     case '=':

CLI/src/Flags.cpp

@@ -31,7 +31,7 @@ static void setLuauFlags(bool state)
 void setLuauFlagsDefault()
 {
     for (Luau::FValue<bool>* flag = Luau::FValue<bool>::list; flag; flag = flag->next)
-        if (strncmp(flag->name, "Luau", 4) == 0 && !Luau::isAnalysisFlagExperimental(flag->name))
+        if (strncmp(flag->name, "Luau", 4) == 0 && !Luau::isFlagExperimental(flag->name))
             flag->value = true;
 }
 

CLI/src/Repl.cpp

@@ -791,6 +791,8 @@ int replMain(int argc, char** argv)
 {
     Luau::assertHandler() = assertionHandler;
 
+    setLuauFlagsDefault();
+
 #ifdef _WIN32
     SetConsoleOutputCP(CP_UTF8);
 #endif

CLI/src/ReplEntry.cpp

@@ -1,10 +1,7 @@
 // This file is part of the Luau programming language and is licensed under MIT License; see LICENSE.txt for details
 #include "Luau/Repl.h"
-#include "Luau/Flags.h"
 
 int main(int argc, char** argv)
 {
-    setLuauFlagsDefault();
-
     return replMain(argc, argv);
 }

CodeGen/src/CodeGen.cpp

@@ -44,6 +44,7 @@
 LUAU_FASTFLAGVARIABLE(DebugCodegenNoOpt)
 LUAU_FASTFLAGVARIABLE(DebugCodegenOptSize)
 LUAU_FASTFLAGVARIABLE(DebugCodegenSkipNumbering)
+LUAU_FASTFLAGVARIABLE(CodegenWiderLoweringStats)
 
 // Per-module IR instruction count limit
 LUAU_FASTINTVARIABLE(CodegenHeuristicsInstructionLimit, 1'048'576) // 1 M

CodeGen/src/CodeGenLower.h

@@ -25,6 +25,7 @@
 LUAU_FASTFLAG(DebugCodegenNoOpt)
 LUAU_FASTFLAG(DebugCodegenOptSize)
 LUAU_FASTFLAG(DebugCodegenSkipNumbering)
+LUAU_FASTFLAG(CodegenWiderLoweringStats)
 LUAU_FASTINT(CodegenHeuristicsInstructionLimit)
 LUAU_FASTINT(CodegenHeuristicsBlockLimit)
 LUAU_FASTINT(CodegenHeuristicsBlockInstructionLimit)
@@ -299,7 +300,8 @@ inline bool lowerFunction(
     CodeGenCompilationResult& codeGenCompilationResult
 )
 {
-    ir.function.stats = stats;
+    if (FFlag::CodegenWiderLoweringStats)
+        ir.function.stats = stats;
 
     killUnusedBlocks(ir.function);
 

CodeGen/src/IrLoweringA64.cpp

@@ -13,6 +13,7 @@
 #include "lgc.h"
 
 LUAU_FASTFLAG(LuauVectorLibNativeDot)
+LUAU_FASTFLAG(LuauCodeGenLerp)
 
 namespace Luau
 {
@@ -705,6 +706,7 @@ void IrLoweringA64::lowerInst(IrInst& inst, uint32_t index, const IrBlock& next)
     }
     case IrCmd::SELECT_NUM:
     {
+        LUAU_ASSERT(FFlag::LuauCodeGenLerp);
         inst.regA64 = regs.allocReuse(KindA64::d, index, {inst.a, inst.b, inst.c, inst.d});
 
         RegisterA64 temp1 = tempDouble(inst.a);

CodeGen/src/IrLoweringX64.cpp

@@ -17,6 +17,7 @@
 #include "lgc.h"
 
 LUAU_FASTFLAG(LuauVectorLibNativeDot)
+LUAU_FASTFLAG(LuauCodeGenLerp)
 
 namespace Luau
 {
@@ -624,6 +625,7 @@ void IrLoweringX64::lowerInst(IrInst& inst, uint32_t index, const IrBlock& next)
     }
     case IrCmd::SELECT_NUM:
     {
+        LUAU_ASSERT(FFlag::LuauCodeGenLerp);
         inst.regX64 = regs.allocRegOrReuse(SizeX64::xmmword, index, {inst.a, inst.c, inst.d}); // can't reuse b if a is a memory operand
 
         ScopedRegX64 tmp{regs, SizeX64::xmmword};

CodeGen/src/IrTranslateBuiltins.cpp

@@ -13,7 +13,9 @@
 static const int kMinMaxUnrolledParams = 5;
 static const int kBit32BinaryOpUnrolledParams = 5;
 
+LUAU_FASTFLAGVARIABLE(LuauVectorLibNativeCodegen);
 LUAU_FASTFLAGVARIABLE(LuauVectorLibNativeDot);
+LUAU_FASTFLAGVARIABLE(LuauCodeGenLerp);
 
 namespace Luau
 {
@@ -295,6 +297,8 @@ static BuiltinImplResult translateBuiltinMathLerp(
     int pcpos
 )
 {
+    LUAU_ASSERT(FFlag::LuauCodeGenLerp);
+
     if (nparams < 3 || nresults > 1)
         return {BuiltinImplType::None, -1};
 
@@ -932,6 +936,8 @@ static BuiltinImplResult translateBuiltinVectorMagnitude(
     int pcpos
 )
 {
+    LUAU_ASSERT(FFlag::LuauVectorLibNativeCodegen);
+
     IrOp arg1 = build.vmReg(arg);
 
     if (nparams != 1 || nresults > 1 || arg1.kind == IrOpKind::Constant)
@@ -979,6 +985,8 @@ static BuiltinImplResult translateBuiltinVectorNormalize(
     int pcpos
 )
 {
+    LUAU_ASSERT(FFlag::LuauVectorLibNativeCodegen);
+
     IrOp arg1 = build.vmReg(arg);
 
     if (nparams != 1 || nresults > 1 || arg1.kind == IrOpKind::Constant)
@@ -1029,6 +1037,8 @@ static BuiltinImplResult translateBuiltinVectorNormalize(
 
 static BuiltinImplResult translateBuiltinVectorCross(IrBuilder& build, int nparams, int ra, int arg, IrOp args, IrOp arg3, int nresults, int pcpos)
 {
+    LUAU_ASSERT(FFlag::LuauVectorLibNativeCodegen);
+
     IrOp arg1 = build.vmReg(arg);
 
     if (nparams != 2 || nresults > 1 || arg1.kind == IrOpKind::Constant || args.kind == IrOpKind::Constant)
@@ -1066,6 +1076,8 @@ static BuiltinImplResult translateBuiltinVectorCross(IrBuilder& build, int npara
 
 static BuiltinImplResult translateBuiltinVectorDot(IrBuilder& build, int nparams, int ra, int arg, IrOp args, IrOp arg3, int nresults, int pcpos)
 {
+    LUAU_ASSERT(FFlag::LuauVectorLibNativeCodegen);
+
     IrOp arg1 = build.vmReg(arg);
 
     if (nparams != 2 || nresults > 1 || arg1.kind == IrOpKind::Constant || args.kind == IrOpKind::Constant)
@@ -1118,6 +1130,8 @@ static BuiltinImplResult translateBuiltinVectorMap1(
     int pcpos
 )
 {
+    LUAU_ASSERT(FFlag::LuauVectorLibNativeCodegen);
+
     IrOp arg1 = build.vmReg(arg);
 
     if (nparams != 1 || nresults > 1 || arg1.kind == IrOpKind::Constant)
@@ -1151,6 +1165,8 @@ static BuiltinImplResult translateBuiltinVectorClamp(
     int pcpos
 )
 {
+    LUAU_ASSERT(FFlag::LuauVectorLibNativeCodegen);
+
     IrOp arg1 = build.vmReg(arg);
 
     if (nparams != 3 || nresults > 1 || arg1.kind == IrOpKind::Constant || args.kind == IrOpKind::Constant || arg3.kind == IrOpKind::Constant)
@@ -1215,6 +1231,8 @@ static BuiltinImplResult translateBuiltinVectorMap2(
     int pcpos
 )
 {
+    LUAU_ASSERT(FFlag::LuauVectorLibNativeCodegen);
+
     IrOp arg1 = build.vmReg(arg);
 
     if (nparams != 2 || nresults > 1 || arg1.kind == IrOpKind::Constant || args.kind == IrOpKind::Constant)
@@ -1255,6 +1273,8 @@ BuiltinImplResult translateBuiltin(
     int pcpos
 )
 {
+    BuiltinImplResult noneResult = {BuiltinImplType::None, -1};
+
     // Builtins are not allowed to handle variadic arguments
     if (nparams == LUA_MULTRET)
         return {BuiltinImplType::None, -1};
@@ -1376,29 +1396,36 @@ BuiltinImplResult translateBuiltin(
     case LBF_BUFFER_WRITEF64:
         return translateBuiltinBufferWrite(build, nparams, ra, arg, args, arg3, nresults, pcpos, IrCmd::BUFFER_WRITEF64, 8, IrCmd::NOP);
     case LBF_VECTOR_MAGNITUDE:
-        return translateBuiltinVectorMagnitude(build, nparams, ra, arg, args, arg3, nresults, pcpos);
+        return FFlag::LuauVectorLibNativeCodegen ? translateBuiltinVectorMagnitude(build, nparams, ra, arg, args, arg3, nresults, pcpos) : noneResult;
     case LBF_VECTOR_NORMALIZE:
-        return translateBuiltinVectorNormalize(build, nparams, ra, arg, args, arg3, nresults, pcpos);
+        return FFlag::LuauVectorLibNativeCodegen ? translateBuiltinVectorNormalize(build, nparams, ra, arg, args, arg3, nresults, pcpos) : noneResult;
     case LBF_VECTOR_CROSS:
-        return translateBuiltinVectorCross(build, nparams, ra, arg, args, arg3, nresults, pcpos);
+        return FFlag::LuauVectorLibNativeCodegen ? translateBuiltinVectorCross(build, nparams, ra, arg, args, arg3, nresults, pcpos) : noneResult;
     case LBF_VECTOR_DOT:
-        return translateBuiltinVectorDot(build, nparams, ra, arg, args, arg3, nresults, pcpos);
+        return FFlag::LuauVectorLibNativeCodegen ? translateBuiltinVectorDot(build, nparams, ra, arg, args, arg3, nresults, pcpos) : noneResult;
     case LBF_VECTOR_FLOOR:
-        return translateBuiltinVectorMap1(build, IrCmd::FLOOR_NUM, nparams, ra, arg, args, arg3, nresults, pcpos);
+        return FFlag::LuauVectorLibNativeCodegen ? translateBuiltinVectorMap1(build, IrCmd::FLOOR_NUM, nparams, ra, arg, args, arg3, nresults, pcpos)
+                                                 : noneResult;
     case LBF_VECTOR_CEIL:
-        return translateBuiltinVectorMap1(build, IrCmd::CEIL_NUM, nparams, ra, arg, args, arg3, nresults, pcpos);
+        return FFlag::LuauVectorLibNativeCodegen ? translateBuiltinVectorMap1(build, IrCmd::CEIL_NUM, nparams, ra, arg, args, arg3, nresults, pcpos)
+                                                 : noneResult;
     case LBF_VECTOR_ABS:
-        return translateBuiltinVectorMap1(build, IrCmd::ABS_NUM, nparams, ra, arg, args, arg3, nresults, pcpos);
+        return FFlag::LuauVectorLibNativeCodegen ? translateBuiltinVectorMap1(build, IrCmd::ABS_NUM, nparams, ra, arg, args, arg3, nresults, pcpos)
+                                                 : noneResult;
     case LBF_VECTOR_SIGN:
-        return translateBuiltinVectorMap1(build, IrCmd::SIGN_NUM, nparams, ra, arg, args, arg3, nresults, pcpos);
+        return FFlag::LuauVectorLibNativeCodegen ? translateBuiltinVectorMap1(build, IrCmd::SIGN_NUM, nparams, ra, arg, args, arg3, nresults, pcpos)
+                                                 : noneResult;
     case LBF_VECTOR_CLAMP:
-        return translateBuiltinVectorClamp(build, nparams, ra, arg, args, arg3, nresults, fallback, pcpos);
+        return FFlag::LuauVectorLibNativeCodegen ? translateBuiltinVectorClamp(build, nparams, ra, arg, args, arg3, nresults, fallback, pcpos)
+                                                 : noneResult;
     case LBF_VECTOR_MIN:
-        return translateBuiltinVectorMap2(build, IrCmd::MIN_NUM, nparams, ra, arg, args, arg3, nresults, pcpos);
+        return FFlag::LuauVectorLibNativeCodegen ? translateBuiltinVectorMap2(build, IrCmd::MIN_NUM, nparams, ra, arg, args, arg3, nresults, pcpos)
+                                                 : noneResult;
     case LBF_VECTOR_MAX:
-        return translateBuiltinVectorMap2(build, IrCmd::MAX_NUM, nparams, ra, arg, args, arg3, nresults, pcpos);
+        return FFlag::LuauVectorLibNativeCodegen ? translateBuiltinVectorMap2(build, IrCmd::MAX_NUM, nparams, ra, arg, args, arg3, nresults, pcpos)
+                                                 : noneResult;
     case LBF_MATH_LERP:
-        return translateBuiltinMathLerp(build, nparams, ra, arg, args, arg3, nresults, fallback, pcpos);
+        return FFlag::LuauCodeGenLerp ? translateBuiltinMathLerp(build, nparams, ra, arg, args, arg3, nresults, fallback, pcpos) : noneResult;
     default:
         return {BuiltinImplType::None, -1};
     }

CodeGen/src/IrUtils.cpp

@@ -17,6 +17,7 @@
 #include <math.h>
 
 LUAU_FASTFLAG(LuauVectorLibNativeDot);
+LUAU_FASTFLAG(LuauCodeGenLerp);
 
 namespace Luau
 {
@@ -662,6 +663,7 @@ void foldConstants(IrBuilder& build, IrFunction& function, IrBlock& block, uint3
         }
         break;
     case IrCmd::SELECT_NUM:
+        LUAU_ASSERT(FFlag::LuauCodeGenLerp);
         if (inst.c.kind == IrOpKind::Constant && inst.d.kind == IrOpKind::Constant)
         {
             double c = function.doubleOp(inst.c);

CodeGen/src/OptimizeConstProp.cpp

@@ -22,6 +22,7 @@ LUAU_FASTINTVARIABLE(LuauCodeGenReuseUdataTagLimit, 64)
 LUAU_FASTINTVARIABLE(LuauCodeGenLiveSlotReuseLimit, 8)
 LUAU_FASTFLAGVARIABLE(DebugLuauAbortingChecks)
 LUAU_FASTFLAG(LuauVectorLibNativeDot)
+LUAU_FASTFLAGVARIABLE(LuauCodeGenLimitLiveSlotReuse)
 
 namespace Luau
 {
@@ -199,7 +200,11 @@ struct ConstPropState
     // Same goes for table array elements as well
     void invalidateHeapTableData()
     {
-        getSlotNodeCache.clear();
+        if (FFlag::LuauCodeGenLimitLiveSlotReuse)
+            getSlotNodeCache.clear();
+        else
+            getSlotNodeCache_DEPRECATED.clear();
+
         checkSlotMatchCache.clear();
 
         getArrAddrCache.clear();
@@ -423,6 +428,8 @@ struct ConstPropState
     // Note that this pressure is approximate, as some values that might have been live at one point could have been marked dead later
     int getMaxInternalOverlap(std::vector<NumberedInstruction>& set, size_t slot)
     {
+        CODEGEN_ASSERT(FFlag::LuauCodeGenLimitLiveSlotReuse);
+
         // Start with one live range for the slot we want to reuse
         int curr = 1;
 
@@ -480,7 +487,9 @@ struct ConstPropState
             regs[i] = RegisterInfo();
 
         maxReg = 0;
-        instPos = 0u;
+
+        if (FFlag::LuauCodeGenLimitLiveSlotReuse)
+            instPos = 0u;
 
         inSafeEnv = false;
         checkedGc = false;
@@ -517,6 +526,7 @@ struct ConstPropState
 
     // Heap changes might affect table state
     std::vector<NumberedInstruction> getSlotNodeCache; // Additionally, pcpos argument might be different
+    std::vector<uint32_t> getSlotNodeCache_DEPRECATED; // Additionally, pcpos argument might be different
     std::vector<uint32_t> checkSlotMatchCache; // Additionally, fallback block argument might be different
 
     std::vector<uint32_t> getArrAddrCache;
@@ -641,7 +651,8 @@ static void handleBuiltinEffects(ConstPropState& state, LuauBuiltinFunction bfid
 
 static void constPropInInst(ConstPropState& state, IrBuilder& build, IrFunction& function, IrBlock& block, IrInst& inst, uint32_t index)
 {
-    state.instPos++;
+    if (FFlag::LuauCodeGenLimitLiveSlotReuse)
+        state.instPos++;
 
     switch (inst.cmd)
     {
@@ -1249,30 +1260,49 @@ static void constPropInInst(ConstPropState& state, IrBuilder& build, IrFunction&
             state.getArrAddrCache.push_back(index);
         break;
     case IrCmd::GET_SLOT_NODE_ADDR:
-        for (size_t i = 0; i < state.getSlotNodeCache.size(); i++)
+        if (FFlag::LuauCodeGenLimitLiveSlotReuse)
         {
-            auto&& [prevIdx, num, lastNum] = state.getSlotNodeCache[i];
-
-            const IrInst& prev = function.instructions[prevIdx];
-
-            if (prev.a == inst.a && prev.c == inst.c)
+            for (size_t i = 0; i < state.getSlotNodeCache.size(); i++)
             {
-                // Check if this reuse will increase the overall register pressure over the limit
-                int limit = FInt::LuauCodeGenLiveSlotReuseLimit;
+                auto&& [prevIdx, num, lastNum] = state.getSlotNodeCache[i];
 
-                if (int(state.getSlotNodeCache.size()) > limit && state.getMaxInternalOverlap(state.getSlotNodeCache, i) > limit)
-                    return;
+                const IrInst& prev = function.instructions[prevIdx];
 
-                // Update live range of the value from the optimization standpoint
-                lastNum = state.instPos;
+                if (prev.a == inst.a && prev.c == inst.c)
+                {
+                    // Check if this reuse will increase the overall register pressure over the limit
+                    int limit = FInt::LuauCodeGenLiveSlotReuseLimit;
 
-                substitute(function, inst, IrOp{IrOpKind::Inst, prevIdx});
-                return; // Break out from both the loop and the switch
+                    if (int(state.getSlotNodeCache.size()) > limit && state.getMaxInternalOverlap(state.getSlotNodeCache, i) > limit)
+                        return;
+
+                    // Update live range of the value from the optimization standpoint
+                    lastNum = state.instPos;
+
+                    substitute(function, inst, IrOp{IrOpKind::Inst, prevIdx});
+                    return; // Break out from both the loop and the switch
+                }
             }
-        }
 
-        if (int(state.getSlotNodeCache.size()) < FInt::LuauCodeGenReuseSlotLimit)
-            state.getSlotNodeCache.push_back({index, state.instPos, state.instPos});
+            if (int(state.getSlotNodeCache.size()) < FInt::LuauCodeGenReuseSlotLimit)
+                state.getSlotNodeCache.push_back({index, state.instPos, state.instPos});
+        }
+        else
+        {
+            for (uint32_t prevIdx : state.getSlotNodeCache_DEPRECATED)
+            {
+                const IrInst& prev = function.instructions[prevIdx];
+
+                if (prev.a == inst.a && prev.c == inst.c)
+                {
+                    substitute(function, inst, IrOp{IrOpKind::Inst, prevIdx});
+                    return; // Break out from both the loop and the switch
+                }
+            }
+
+            if (int(state.getSlotNodeCache_DEPRECATED.size()) < FInt::LuauCodeGenReuseSlotLimit)
+                state.getSlotNodeCache_DEPRECATED.push_back(index);
+        }
         break;
     case IrCmd::GET_HASH_NODE_ADDR:
     case IrCmd::GET_CLOSURE_UPVAL_ADDR:

Common/include/Luau/ExperimentalFlags.h

@@ -6,11 +6,10 @@
 namespace Luau
 {
 
-inline bool isAnalysisFlagExperimental(const char* flag)
+inline bool isFlagExperimental(const char* flag)
 {
     // Flags in this list are disabled by default in various command-line tools. They may have behavior that is not fully final,
-    // or critical bugs that are found after the code has been submitted. This list is intended _only_ for flags that affect
-    // Luau's type checking. Flags that may change runtime behavior (e.g.: parser or VM flags) are not appropriate for this list.
+    // or critical bugs that are found after the code has been submitted.
     static const char* const kList[] = {
         "LuauInstantiateInSubtyping",      // requires some fixes to lua-apps code
         "LuauFixIndexerSubtypingOrdering", // requires some small fixes to lua-apps code since this fixes a false negative

Compiler/src/BuiltinFolding.cpp

@@ -5,6 +5,9 @@
 
 #include <math.h>
 
+LUAU_FASTFLAGVARIABLE(LuauVector2Constants)
+LUAU_FASTFLAG(LuauCompileMathLerp)
+
 namespace Luau
 {
 namespace Compile
@@ -473,7 +476,7 @@ Constant foldBuiltin(int bfid, const Constant* args, size_t count)
     case LBF_VECTOR:
         if (count >= 2 && args[0].type == Constant::Type_Number && args[1].type == Constant::Type_Number)
         {
-            if (count == 2)
+            if (count == 2 && FFlag::LuauVector2Constants)
                 return cvector(args[0].valueNumber, args[1].valueNumber, 0.0, 0.0);
             else if (count == 3 && args[2].type == Constant::Type_Number)
                 return cvector(args[0].valueNumber, args[1].valueNumber, args[2].valueNumber, 0.0);
@@ -483,7 +486,8 @@ Constant foldBuiltin(int bfid, const Constant* args, size_t count)
         break;
 
     case LBF_MATH_LERP:
-        if (count == 3 && args[0].type == Constant::Type_Number && args[1].type == Constant::Type_Number && args[2].type == Constant::Type_Number)
+        if (FFlag::LuauCompileMathLerp && count == 3 && args[0].type == Constant::Type_Number && args[1].type == Constant::Type_Number &&
+            args[2].type == Constant::Type_Number)
         {
             double a = args[0].valueNumber;
             double b = args[1].valueNumber;

Compiler/src/Builtins.cpp

@@ -7,6 +7,8 @@
 
 #include <array>
 
+LUAU_FASTFLAGVARIABLE(LuauCompileMathLerp)
+
 namespace Luau
 {
 namespace Compile
@@ -137,7 +139,7 @@ static int getBuiltinFunctionId(const Builtin& builtin, const CompileOptions& op
             return LBF_MATH_SIGN;
         if (builtin.method == "round")
             return LBF_MATH_ROUND;
-        if (builtin.method == "lerp")
+        if (FFlag::LuauCompileMathLerp && builtin.method == "lerp")
             return LBF_MATH_LERP;
     }
 
@@ -554,6 +556,7 @@ BuiltinInfo getBuiltinInfo(int bfid)
         return {-1, 1}; // variadic
 
     case LBF_MATH_LERP:
+        LUAU_ASSERT(FFlag::LuauCompileMathLerp);
         return {3, 1, BuiltinInfo::Flag_NoneSafe};
     }
 

Compiler/src/Compiler.cpp

@@ -26,8 +26,6 @@ LUAU_FASTINTVARIABLE(LuauCompileInlineThreshold, 25)
 LUAU_FASTINTVARIABLE(LuauCompileInlineThresholdMaxBoost, 300)
 LUAU_FASTINTVARIABLE(LuauCompileInlineDepth, 5)
 
-LUAU_FASTFLAGVARIABLE(LuauSeparateCompilerTypeInfo)
-
 namespace Luau
 {
 
@@ -4271,40 +4269,20 @@ void compileOrThrow(BytecodeBuilder& bytecode, const ParseResult& parseResult, c
     }
 
     // computes type information for all functions based on type annotations
-    if (FFlag::LuauSeparateCompilerTypeInfo)
-    {
-        if (options.typeInfoLevel >= 1 || options.optimizationLevel >= 2)
-            buildTypeMap(
-                compiler.functionTypes,
-                compiler.localTypes,
-                compiler.exprTypes,
-                root,
-                options.vectorType,
-                compiler.userdataTypes,
-                compiler.builtinTypes,
-                compiler.builtins,
-                compiler.globals,
-                options.libraryMemberTypeCb,
-                bytecode
-            );
-    }
-    else
-    {
-        if (options.typeInfoLevel >= 1)
-            buildTypeMap(
-                compiler.functionTypes,
-                compiler.localTypes,
-                compiler.exprTypes,
-                root,
-                options.vectorType,
-                compiler.userdataTypes,
-                compiler.builtinTypes,
-                compiler.builtins,
-                compiler.globals,
-                options.libraryMemberTypeCb,
-                bytecode
-            );
-    }
+    if (options.typeInfoLevel >= 1)
+        buildTypeMap(
+            compiler.functionTypes,
+            compiler.localTypes,
+            compiler.exprTypes,
+            root,
+            options.vectorType,
+            compiler.userdataTypes,
+            compiler.builtinTypes,
+            compiler.builtins,
+            compiler.globals,
+            options.libraryMemberTypeCb,
+            bytecode
+        );
 
     for (AstExprFunction* expr : functions)
     {

Compiler/src/Types.cpp

@@ -125,10 +125,6 @@ static LuauBytecodeType getType(
     {
         return getType(group->type, generics, typeAliases, resolveAliases, hostVectorType, userdataTypes, bytecode);
     }
-    else if (const AstTypeOptional* optional = ty->as<AstTypeOptional>())
-    {
-        return LBC_TYPE_NIL;
-    }
 
     return LBC_TYPE_ANY;
 }

Sources.cmake

@@ -169,6 +169,7 @@ target_sources(Luau.CodeGen PRIVATE
 # Luau.Analysis Sources
 target_sources(Luau.Analysis PRIVATE
     Analysis/include/Luau/Anyification.h
+    Analysis/include/Luau/AnyTypeSummary.h
     Analysis/include/Luau/ApplyTypeFunction.h
     Analysis/include/Luau/AstJsonEncoder.h
     Analysis/include/Luau/AstQuery.h
@@ -247,6 +248,7 @@ target_sources(Luau.Analysis PRIVATE
     Analysis/include/Luau/VisitType.h
 
     Analysis/src/Anyification.cpp
+    Analysis/src/AnyTypeSummary.cpp
     Analysis/src/ApplyTypeFunction.cpp
     Analysis/src/AstJsonEncoder.cpp
     Analysis/src/AstQuery.cpp
@@ -264,7 +266,6 @@ target_sources(Luau.Analysis PRIVATE
     Analysis/src/EmbeddedBuiltinDefinitions.cpp
     Analysis/src/Error.cpp
     Analysis/src/EqSatSimplification.cpp
-    Analysis/src/FileResolver.cpp
     Analysis/src/FragmentAutocomplete.cpp
     Analysis/src/Frontend.cpp
     Analysis/src/Generalization.cpp
@@ -431,6 +432,7 @@ endif()
 if(TARGET Luau.UnitTest)
     # Luau.UnitTest Sources
     target_sources(Luau.UnitTest PRIVATE
+        tests/AnyTypeSummary.test.cpp
         tests/AssemblyBuilderA64.test.cpp
         tests/AssemblyBuilderX64.test.cpp
         tests/AstJsonEncoder.test.cpp

VM/include/lua.h

@@ -327,12 +327,9 @@ LUA_API void lua_setuserdatadtor(lua_State* L, int tag, lua_Destructor dtor);
 LUA_API lua_Destructor lua_getuserdatadtor(lua_State* L, int tag);
 
 // alternative access for metatables already registered with luaL_newmetatable
-// used by lua_newuserdatataggedwithmetatable to create tagged userdata with the associated metatable assigned
-LUA_API void lua_setuserdatametatable(lua_State* L, int tag);
+LUA_API void lua_setuserdatametatable(lua_State* L, int tag, int idx);
 LUA_API void lua_getuserdatametatable(lua_State* L, int tag);
 
-LUA_API void lua_setuserdatametatable_DEPRECATED(lua_State* L, int tag, int idx); // Deprecated for incorrect behavior with 'idx != -1'
-
 LUA_API void lua_setlightuserdataname(lua_State* L, int tag, const char* name);
 LUA_API const char* lua_getlightuserdataname(lua_State* L, int tag);
 

VM/src/lapi.cpp

@@ -1470,16 +1470,7 @@ lua_Destructor lua_getuserdatadtor(lua_State* L, int tag)
     return L->global->udatagc[tag];
 }
 
-void lua_setuserdatametatable(lua_State* L, int tag)
-{
-    api_check(L, unsigned(tag) < LUA_UTAG_LIMIT);
-    api_check(L, !L->global->udatamt[tag]); // reassignment not supported
-    api_check(L, ttistable(L->top - 1));
-    L->global->udatamt[tag] = hvalue(L->top - 1);
-    L->top--;
-}
-
-void lua_setuserdatametatable_DEPRECATED(lua_State* L, int tag, int idx)
+void lua_setuserdatametatable(lua_State* L, int tag, int idx)
 {
     api_check(L, unsigned(tag) < LUA_UTAG_LIMIT);
     api_check(L, !L->global->udatamt[tag]); // reassignment not supported

VM/src/lbuflib.cpp

@@ -10,6 +10,8 @@
 
 #include <string.h>
 
+LUAU_FASTFLAGVARIABLE(LuauBufferBitMethods2)
+
 // while C API returns 'size_t' for binary compatibility in case of future extensions,
 // in the current implementation, length and offset are limited to 31 bits
 // because offset is limited to an integer, a single 64bit comparison can be used and will not overflow
@@ -328,6 +330,34 @@ static int buffer_writebits(lua_State* L)
     return 0;
 }
 
+static const luaL_Reg bufferlib_DEPRECATED[] = {
+    {"create", buffer_create},
+    {"fromstring", buffer_fromstring},
+    {"tostring", buffer_tostring},
+    {"readi8", buffer_readinteger<int8_t>},
+    {"readu8", buffer_readinteger<uint8_t>},
+    {"readi16", buffer_readinteger<int16_t>},
+    {"readu16", buffer_readinteger<uint16_t>},
+    {"readi32", buffer_readinteger<int32_t>},
+    {"readu32", buffer_readinteger<uint32_t>},
+    {"readf32", buffer_readfp<float, uint32_t>},
+    {"readf64", buffer_readfp<double, uint64_t>},
+    {"writei8", buffer_writeinteger<int8_t>},
+    {"writeu8", buffer_writeinteger<uint8_t>},
+    {"writei16", buffer_writeinteger<int16_t>},
+    {"writeu16", buffer_writeinteger<uint16_t>},
+    {"writei32", buffer_writeinteger<int32_t>},
+    {"writeu32", buffer_writeinteger<uint32_t>},
+    {"writef32", buffer_writefp<float, uint32_t>},
+    {"writef64", buffer_writefp<double, uint64_t>},
+    {"readstring", buffer_readstring},
+    {"writestring", buffer_writestring},
+    {"len", buffer_len},
+    {"copy", buffer_copy},
+    {"fill", buffer_fill},
+    {NULL, NULL},
+};
+
 static const luaL_Reg bufferlib[] = {
     {"create", buffer_create},
     {"fromstring", buffer_fromstring},
@@ -360,7 +390,7 @@ static const luaL_Reg bufferlib[] = {
 
 int luaopen_buffer(lua_State* L)
 {
-    luaL_register(L, LUA_BUFFERLIBNAME, bufferlib);
+    luaL_register(L, LUA_BUFFERLIBNAME, FFlag::LuauBufferBitMethods2 ? bufferlib : bufferlib_DEPRECATED);
 
     return 1;
 }

VM/src/lbuiltins.cpp

@@ -25,6 +25,8 @@
 #endif
 #endif
 
+LUAU_FASTFLAG(LuauVector2Constructor)
+
 // luauF functions implement FASTCALL instruction that performs a direct execution of some builtin functions from the VM
 // The rule of thumb is that FASTCALL functions can not call user code, yield, fail, or reallocate stack.
 // If types of the arguments mismatch, luauF_* needs to return -1 and the execution will fall back to the usual call path
@@ -1055,33 +1057,60 @@ 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 (nparams >= 2 && nresults <= 1 && ttisnumber(arg0) && ttisnumber(args))
+    if (FFlag::LuauVector2Constructor)
     {
-        float x = (float)nvalue(arg0);
-        float y = (float)nvalue(args);
-        float z = 0.0f;
-
-        if (nparams >= 3)
+        if (nparams >= 2 && nresults <= 1 && ttisnumber(arg0) && ttisnumber(args))
         {
-            if (!ttisnumber(args + 1))
-                return -1;
-            z = (float)nvalue(args + 1);
-        }
+            float x = (float)nvalue(arg0);
+            float y = (float)nvalue(args);
+            float z = 0.0f;
+
+            if (nparams >= 3)
+            {
+                if (!ttisnumber(args + 1))
+                    return -1;
+                z = (float)nvalue(args + 1);
+            }
 
 #if LUA_VECTOR_SIZE == 4
-        float w = 0.0f;
-        if (nparams >= 4)
-        {
-            if (!ttisnumber(args + 2))
-                return -1;
-            w = (float)nvalue(args + 2);
-        }
-        setvvalue(res, x, y, z, w);
+            float w = 0.0f;
+            if (nparams >= 4)
+            {
+                if (!ttisnumber(args + 2))
+                    return -1;
+                w = (float)nvalue(args + 2);
+            }
+            setvvalue(res, x, y, z, w);
 #else
-        setvvalue(res, x, y, z, 0.0f);
+            setvvalue(res, x, y, z, 0.0f);
 #endif
 
-        return 1;
+            return 1;
+        }
+    }
+    else
+    {
+        if (nparams >= 3 && nresults <= 1 && ttisnumber(arg0) && ttisnumber(args) && ttisnumber(args + 1))
+        {
+            double x = nvalue(arg0);
+            double y = nvalue(args);
+            double z = nvalue(args + 1);
+
+#if LUA_VECTOR_SIZE == 4
+            double w = 0.0;
+            if (nparams >= 4)
+            {
+                if (!ttisnumber(args + 2))
+                    return -1;
+                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;
+        }
     }
 
     return -1;

VM/src/lmathlib.cpp

@@ -7,6 +7,8 @@
 #include <math.h>
 #include <time.h>
 
+LUAU_FASTFLAGVARIABLE(LuauMathLerp)
+
 #undef PI
 #define PI (3.14159265358979323846)
 #define RADIANS_PER_DEGREE (PI / 180.0)
@@ -461,7 +463,6 @@ static const luaL_Reg mathlib[] = {
     {"sign", math_sign},
     {"round", math_round},
     {"map", math_map},
-    {"lerp", math_lerp},
     {NULL, NULL},
 };
 
@@ -482,5 +483,11 @@ int luaopen_math(lua_State* L)
     lua_pushnumber(L, HUGE_VAL);
     lua_setfield(L, -2, "huge");
 
+    if (FFlag::LuauMathLerp)
+    {
+        lua_pushcfunction(L, math_lerp, "lerp");
+        lua_setfield(L, -2, "lerp");
+    }
+
     return 1;
 }

VM/src/lveclib.cpp

@@ -6,6 +6,8 @@
 
 #include <math.h>
 
+LUAU_FASTFLAGVARIABLE(LuauVector2Constructor)
+
 static int vector_create(lua_State* L)
 {
     // checking argument count to avoid accepting 'nil' as a valid value
@@ -13,7 +15,7 @@ static int vector_create(lua_State* L)
 
     double x = luaL_checknumber(L, 1);
     double y = luaL_checknumber(L, 2);
-    double z = count >= 3 ? luaL_checknumber(L, 3) : 0.0;
+    double z = FFlag::LuauVector2Constructor ? (count >= 3 ? luaL_checknumber(L, 3) : 0.0) : luaL_checknumber(L, 3);
 
 #if LUA_VECTOR_SIZE == 4
     double w = count >= 4 ? luaL_checknumber(L, 4) : 0.0;