Sync to upstream/release/566

Analysis/include/Luau/Breadcrumb.h

@@ -0,0 +1,75 @@
+// This file is part of the Luau programming language and is licensed under MIT License; see LICENSE.txt for details
+#pragma once
+
+#include "Luau/Def.h"
+#include "Luau/NotNull.h"
+#include "Luau/Variant.h"
+
+#include <string>
+#include <optional>
+
+namespace Luau
+{
+
+using NullableBreadcrumbId = const struct Breadcrumb*;
+using BreadcrumbId = NotNull<const struct Breadcrumb>;
+
+struct FieldMetadata
+{
+    std::string prop;
+};
+
+struct SubscriptMetadata
+{
+    BreadcrumbId key;
+};
+
+using Metadata = Variant<FieldMetadata, SubscriptMetadata>;
+
+struct Breadcrumb
+{
+    NullableBreadcrumbId previous;
+    DefId def;
+    std::optional<Metadata> metadata;
+    std::vector<BreadcrumbId> children;
+};
+
+inline Breadcrumb* asMutable(NullableBreadcrumbId breadcrumb)
+{
+    LUAU_ASSERT(breadcrumb);
+    return const_cast<Breadcrumb*>(breadcrumb);
+}
+
+template<typename T>
+const T* getMetadata(NullableBreadcrumbId breadcrumb)
+{
+    if (!breadcrumb || !breadcrumb->metadata)
+        return nullptr;
+
+    return get_if<T>(&*breadcrumb->metadata);
+}
+
+struct BreadcrumbArena
+{
+    TypedAllocator<Breadcrumb> allocator;
+
+    template<typename... Args>
+    BreadcrumbId add(NullableBreadcrumbId previous, DefId def, Args&&... args)
+    {
+        Breadcrumb* bc = allocator.allocate(Breadcrumb{previous, def, std::forward<Args>(args)...});
+        if (previous)
+            asMutable(previous)->children.push_back(NotNull{bc});
+        return NotNull{bc};
+    }
+
+    template<typename T, typename... Args>
+    BreadcrumbId emplace(NullableBreadcrumbId previous, DefId def, Args&&... args)
+    {
+        Breadcrumb* bc = allocator.allocate(Breadcrumb{previous, def, Metadata{T{std::forward<Args>(args)...}}});
+        if (previous)
+            asMutable(previous)->children.push_back(NotNull{bc});
+        return NotNull{bc};
+    }
+};
+
+} // namespace Luau

Analysis/include/Luau/Constraint.h

@@ -2,7 +2,6 @@
 #pragma once
 
 #include "Luau/Ast.h" // Used for some of the enumerations
-#include "Luau/Def.h"
 #include "Luau/DenseHash.h"
 #include "Luau/NotNull.h"
 #include "Luau/Type.h"

Analysis/include/Luau/ConstraintGraphBuilder.h

@@ -224,7 +224,7 @@ struct ConstraintGraphBuilder
      * @param inTypeArguments whether we are resolving a type that's contained within type arguments, `<...>`.
      * @return the type of the AST annotation.
      **/
-    TypeId resolveType(const ScopePtr& scope, AstType* ty, bool inTypeArguments);
+    TypeId resolveType(const ScopePtr& scope, AstType* ty, bool inTypeArguments, bool replaceErrorWithFresh = false);
 
     /**
      * Resolves a type pack from its AST annotation.
@@ -233,7 +233,7 @@ struct ConstraintGraphBuilder
      * @param inTypeArguments whether we are resolving a type that's contained within type arguments, `<...>`.
      * @return the type pack of the AST annotation.
      **/
-    TypePackId resolveTypePack(const ScopePtr& scope, AstTypePack* tp, bool inTypeArguments);
+    TypePackId resolveTypePack(const ScopePtr& scope, AstTypePack* tp, bool inTypeArguments, bool replaceErrorWithFresh = false);
 
     /**
      * Resolves a type pack from its AST annotation.
@@ -242,7 +242,7 @@ struct ConstraintGraphBuilder
      * @param inTypeArguments whether we are resolving a type that's contained within type arguments, `<...>`.
      * @return the type pack of the AST annotation.
      **/
-    TypePackId resolveTypePack(const ScopePtr& scope, const AstTypeList& list, bool inTypeArguments);
+    TypePackId resolveTypePack(const ScopePtr& scope, const AstTypeList& list, bool inTypeArguments, bool replaceErrorWithFresh = false);
 
     /**
      * Creates generic types given a list of AST definitions, resolving default
@@ -282,10 +282,17 @@ struct ConstraintGraphBuilder
      * initial scan of the AST and note what globals are defined.
      */
     void prepopulateGlobalScope(const ScopePtr& globalScope, AstStatBlock* program);
+
+    /** Given a function type annotation, return a vector describing the expected types of the calls to the function
+     *  For example, calling a function with annotation ((number) -> string & ((string) -> number))
+     *  yields a vector of size 1, with value: [number | string]
+     */
+    std::vector<std::optional<TypeId>> getExpectedCallTypesForFunctionOverloads(const TypeId fnType);
 };
 
 /** Borrow a vector of pointers from a vector of owning pointers to constraints.
  */
 std::vector<NotNull<Constraint>> borrowConstraints(const std::vector<ConstraintPtr>& constraints);
 
+
 } // namespace Luau

Analysis/include/Luau/ConstraintSolver.h

@@ -132,8 +132,8 @@ struct ConstraintSolver
     bool tryDispatchIterableFunction(
         TypeId nextTy, TypeId tableTy, TypeId firstIndexTy, const IterableConstraint& c, NotNull<const Constraint> constraint, bool force);
 
-    std::optional<TypeId> lookupTableProp(TypeId subjectType, const std::string& propName);
-    std::optional<TypeId> lookupTableProp(TypeId subjectType, const std::string& propName, std::unordered_set<TypeId>& seen);
+    std::pair<std::vector<TypeId>, std::optional<TypeId>> lookupTableProp(TypeId subjectType, const std::string& propName);
+    std::pair<std::vector<TypeId>, std::optional<TypeId>> lookupTableProp(TypeId subjectType, const std::string& propName, std::unordered_set<TypeId>& seen);
 
     void block(NotNull<const Constraint> target, NotNull<const Constraint> constraint);
     /**

Analysis/include/Luau/DataFlowGraph.h

@@ -3,6 +3,7 @@
 
 // Do not include LValue. It should never be used here.
 #include "Luau/Ast.h"
+#include "Luau/Breadcrumb.h"
 #include "Luau/DenseHash.h"
 #include "Luau/Def.h"
 #include "Luau/Symbol.h"
@@ -17,39 +18,44 @@ struct DataFlowGraph
     DataFlowGraph(DataFlowGraph&&) = default;
     DataFlowGraph& operator=(DataFlowGraph&&) = default;
 
-    // TODO: AstExprLocal, AstExprGlobal, and AstLocal* are guaranteed never to return nullopt.
-    // We leave them to return an optional as we build it out, but the end state is for them to return a non-optional DefId.
-    std::optional<DefId> getDef(const AstExpr* expr) const;
-    std::optional<DefId> getDef(const AstLocal* local) const;
+    NullableBreadcrumbId getBreadcrumb(const AstExpr* expr) const;
 
-    /// Retrieve the Def that corresponds to the given Symbol.
-    ///
-    /// We do not perform dataflow analysis on globals, so this function always
-    /// yields nullopt when passed a global Symbol.
-    std::optional<DefId> getDef(const Symbol& symbol) const;
+    BreadcrumbId getBreadcrumb(const AstLocal* local) const;
+    BreadcrumbId getBreadcrumb(const AstExprLocal* local) const;
+    BreadcrumbId getBreadcrumb(const AstExprGlobal* global) const;
+
+    BreadcrumbId getBreadcrumb(const AstStatDeclareGlobal* global) const;
+    BreadcrumbId getBreadcrumb(const AstStatDeclareFunction* func) const;
 
 private:
     DataFlowGraph() = default;
 
     DataFlowGraph(const DataFlowGraph&) = delete;
     DataFlowGraph& operator=(const DataFlowGraph&) = delete;
 
-    DefArena arena;
-    DenseHashMap<const AstExpr*, const Def*> astDefs{nullptr};
-    DenseHashMap<const AstLocal*, const Def*> localDefs{nullptr};
+    DefArena defs;
+    BreadcrumbArena breadcrumbs;
+
+    DenseHashMap<const AstExpr*, NullableBreadcrumbId> astBreadcrumbs{nullptr};
+
+    // Sometimes we don't have the AstExprLocal* but we have AstLocal*, and sometimes we need to extract that DefId.
+    DenseHashMap<const AstLocal*, NullableBreadcrumbId> localBreadcrumbs{nullptr};
+
+    // There's no AstStatDeclaration, and it feels useless to introduce it just to enforce an invariant in one place.
+    // All keys in this maps are really only statements that ambiently declares a symbol.
+    DenseHashMap<const AstStat*, NullableBreadcrumbId> declaredBreadcrumbs{nullptr};
 
     friend struct DataFlowGraphBuilder;
 };
 
 struct DfgScope
 {
     DfgScope* parent;
-    DenseHashMap<Symbol, const Def*> bindings{Symbol{}};
-};
+    DenseHashMap<Symbol, NullableBreadcrumbId> bindings{Symbol{}};
+    DenseHashMap<const Def*, std::unordered_map<std::string, NullableBreadcrumbId>> props{nullptr};
 
-struct ExpressionFlowGraph
-{
-    std::optional<DefId> def;
+    NullableBreadcrumbId lookup(Symbol symbol) const;
+    NullableBreadcrumbId lookup(DefId def, const std::string& key) const;
 };
 
 // Currently unsound. We do not presently track the control flow of the program.
@@ -65,23 +71,19 @@ struct DataFlowGraphBuilder
     DataFlowGraphBuilder& operator=(const DataFlowGraphBuilder&) = delete;
 
     DataFlowGraph graph;
-    NotNull<DefArena> arena{&graph.arena};
-    struct InternalErrorReporter* handle;
-    std::vector<std::unique_ptr<DfgScope>> scopes;
+    NotNull<DefArena> defs{&graph.defs};
+    NotNull<BreadcrumbArena> breadcrumbs{&graph.breadcrumbs};
 
-    // Does not belong in DataFlowGraphBuilder, but the old solver allows properties to escape the scope they were defined in,
-    // so we will need to be able to emulate this same behavior here too. We can kill this once we have better flow sensitivity.
-    DenseHashMap<const Def*, std::unordered_map<std::string, const Def*>> props{nullptr};
+    struct InternalErrorReporter* handle = nullptr;
+    DfgScope* moduleScope = nullptr;
 
-    DfgScope* childScope(DfgScope* scope);
+    std::vector<std::unique_ptr<DfgScope>> scopes;
 
-    std::optional<DefId> use(DfgScope* scope, Symbol symbol, AstExpr* e);
-    DefId use(DefId def, AstExprIndexName* e);
+    DfgScope* childScope(DfgScope* scope);
 
     void visit(DfgScope* scope, AstStatBlock* b);
     void visitBlockWithoutChildScope(DfgScope* scope, AstStatBlock* b);
 
-    // TODO: visit type aliases
     void visit(DfgScope* scope, AstStat* s);
     void visit(DfgScope* scope, AstStatIf* i);
     void visit(DfgScope* scope, AstStatWhile* w);
@@ -97,24 +99,52 @@ struct DataFlowGraphBuilder
     void visit(DfgScope* scope, AstStatCompoundAssign* c);
     void visit(DfgScope* scope, AstStatFunction* f);
     void visit(DfgScope* scope, AstStatLocalFunction* l);
-
-    ExpressionFlowGraph visitExpr(DfgScope* scope, AstExpr* e);
-    ExpressionFlowGraph visitExpr(DfgScope* scope, AstExprLocal* l);
-    ExpressionFlowGraph visitExpr(DfgScope* scope, AstExprGlobal* g);
-    ExpressionFlowGraph visitExpr(DfgScope* scope, AstExprCall* c);
-    ExpressionFlowGraph visitExpr(DfgScope* scope, AstExprIndexName* i);
-    ExpressionFlowGraph visitExpr(DfgScope* scope, AstExprIndexExpr* i);
-    ExpressionFlowGraph visitExpr(DfgScope* scope, AstExprFunction* f);
-    ExpressionFlowGraph visitExpr(DfgScope* scope, AstExprTable* t);
-    ExpressionFlowGraph visitExpr(DfgScope* scope, AstExprUnary* u);
-    ExpressionFlowGraph visitExpr(DfgScope* scope, AstExprBinary* b);
-    ExpressionFlowGraph visitExpr(DfgScope* scope, AstExprTypeAssertion* t);
-    ExpressionFlowGraph visitExpr(DfgScope* scope, AstExprIfElse* i);
-    ExpressionFlowGraph visitExpr(DfgScope* scope, AstExprInterpString* i);
-
-    // TODO: visitLValue
-    // TODO: visitTypes (because of typeof which has access to values namespace, needs unreachable scope)
-    // TODO: visitTypePacks (because of typeof which has access to values namespace, needs unreachable scope)
+    void visit(DfgScope* scope, AstStatTypeAlias* t);
+    void visit(DfgScope* scope, AstStatDeclareGlobal* d);
+    void visit(DfgScope* scope, AstStatDeclareFunction* d);
+    void visit(DfgScope* scope, AstStatDeclareClass* d);
+    void visit(DfgScope* scope, AstStatError* error);
+
+    BreadcrumbId visitExpr(DfgScope* scope, AstExpr* e);
+    BreadcrumbId visitExpr(DfgScope* scope, AstExprLocal* l);
+    BreadcrumbId visitExpr(DfgScope* scope, AstExprGlobal* g);
+    BreadcrumbId visitExpr(DfgScope* scope, AstExprCall* c);
+    BreadcrumbId visitExpr(DfgScope* scope, AstExprIndexName* i);
+    BreadcrumbId visitExpr(DfgScope* scope, AstExprIndexExpr* i);
+    BreadcrumbId visitExpr(DfgScope* scope, AstExprFunction* f);
+    BreadcrumbId visitExpr(DfgScope* scope, AstExprTable* t);
+    BreadcrumbId visitExpr(DfgScope* scope, AstExprUnary* u);
+    BreadcrumbId visitExpr(DfgScope* scope, AstExprBinary* b);
+    BreadcrumbId visitExpr(DfgScope* scope, AstExprTypeAssertion* t);
+    BreadcrumbId visitExpr(DfgScope* scope, AstExprIfElse* i);
+    BreadcrumbId visitExpr(DfgScope* scope, AstExprInterpString* i);
+    BreadcrumbId visitExpr(DfgScope* scope, AstExprError* error);
+
+    void visitLValue(DfgScope* scope, AstExpr* e);
+    void visitLValue(DfgScope* scope, AstExprLocal* l);
+    void visitLValue(DfgScope* scope, AstExprGlobal* g);
+    void visitLValue(DfgScope* scope, AstExprIndexName* i);
+    void visitLValue(DfgScope* scope, AstExprIndexExpr* i);
+    void visitLValue(DfgScope* scope, AstExprError* e);
+
+    void visitType(DfgScope* scope, AstType* t);
+    void visitType(DfgScope* scope, AstTypeReference* r);
+    void visitType(DfgScope* scope, AstTypeTable* t);
+    void visitType(DfgScope* scope, AstTypeFunction* f);
+    void visitType(DfgScope* scope, AstTypeTypeof* t);
+    void visitType(DfgScope* scope, AstTypeUnion* u);
+    void visitType(DfgScope* scope, AstTypeIntersection* i);
+    void visitType(DfgScope* scope, AstTypeError* error);
+
+    void visitTypePack(DfgScope* scope, AstTypePack* p);
+    void visitTypePack(DfgScope* scope, AstTypePackExplicit* e);
+    void visitTypePack(DfgScope* scope, AstTypePackVariadic* v);
+    void visitTypePack(DfgScope* scope, AstTypePackGeneric* g);
+
+    void visitTypeList(DfgScope* scope, AstTypeList l);
+
+    void visitGenerics(DfgScope* scope, AstArray<AstGenericType> g);
+    void visitGenericPacks(DfgScope* scope, AstArray<AstGenericTypePack> g);
 };
 
 } // namespace Luau

Analysis/include/Luau/Def.h

@@ -14,12 +14,6 @@ namespace Luau
 struct Def;
 using DefId = NotNull<const Def>;
 
-struct FieldMetadata
-{
-    DefId parent;
-    std::string propName;
-};
-
 /**
  * A cell is a "single-object" value.
  *
@@ -29,7 +23,6 @@ struct FieldMetadata
  */
 struct Cell
 {
-    std::optional<struct FieldMetadata> field;
 };
 
 /**
@@ -83,7 +76,6 @@ struct DefArena
     TypedAllocator<Def> allocator;
 
     DefId freshCell();
-    DefId freshCell(DefId parent, const std::string& prop);
     // TODO: implement once we have cases where we need to merge in definitions
     // DefId phi(const std::vector<DefId>& defs);
 };

Analysis/include/Luau/Frontend.h

@@ -162,8 +162,7 @@ struct Frontend
     ScopePtr getGlobalScope();
 
 private:
-    ModulePtr check(const SourceModule& sourceModule, Mode mode, std::vector<RequireCycle> requireCycles,
-        bool forAutocomplete = false);
+    ModulePtr check(const SourceModule& sourceModule, Mode mode, std::vector<RequireCycle> requireCycles, bool forAutocomplete = false, bool recordJsonLog = false);
 
     std::pair<SourceNode*, SourceModule*> getSourceNode(const ModuleName& name);
     SourceModule parse(const ModuleName& name, std::string_view src, const ParseOptions& parseOptions);
@@ -202,16 +201,12 @@ struct Frontend
     ScopePtr globalScope;
 };
 
-ModulePtr check(
-    const SourceModule& sourceModule,
-    const std::vector<RequireCycle>& requireCycles,
-    NotNull<BuiltinTypes> builtinTypes,
-    NotNull<InternalErrorReporter> iceHandler,
-    NotNull<ModuleResolver> moduleResolver,
-    NotNull<FileResolver> fileResolver,
-    const ScopePtr& globalScope,
-    NotNull<UnifierSharedState> unifierState,
-    FrontendOptions options
-);
+ModulePtr check(const SourceModule& sourceModule, const std::vector<RequireCycle>& requireCycles, NotNull<BuiltinTypes> builtinTypes,
+    NotNull<InternalErrorReporter> iceHandler, NotNull<ModuleResolver> moduleResolver, NotNull<FileResolver> fileResolver,
+    const ScopePtr& globalScope, FrontendOptions options);
+
+ModulePtr check(const SourceModule& sourceModule, const std::vector<RequireCycle>& requireCycles, NotNull<BuiltinTypes> builtinTypes,
+    NotNull<InternalErrorReporter> iceHandler, NotNull<ModuleResolver> moduleResolver, NotNull<FileResolver> fileResolver,
+    const ScopePtr& globalScope, FrontendOptions options, bool recordJsonLog);
 
 } // namespace Luau