[Property Wrappers] Fix computation of lvalue-ness in buildStorageReference

include/swift/AST/ASTTypeIDZone.def

@@ -43,6 +43,8 @@ SWIFT_TYPEID_NAMED(NamedPattern *, NamedPattern)
 SWIFT_TYPEID_NAMED(NominalTypeDecl *, NominalTypeDecl)
 SWIFT_TYPEID_NAMED(OpaqueTypeDecl *, OpaqueTypeDecl)
 SWIFT_TYPEID_NAMED(OperatorDecl *, OperatorDecl)
+SWIFT_TYPEID_NAMED(Optional<PropertyWrapperLValueness>,
+                   PropertyWrapperLValueness)
 SWIFT_TYPEID_NAMED(Optional<PropertyWrapperMutability>,
                    PropertyWrapperMutability)
 SWIFT_TYPEID_NAMED(ParamDecl *, ParamDecl)

include/swift/AST/ASTTypeIDs.h

@@ -46,6 +46,7 @@ class PrecedenceGroupDecl;
 struct PropertyWrapperBackingPropertyInfo;
 struct PropertyWrapperTypeInfo;
 enum class CtorInitializerKind;
+struct PropertyWrapperLValueness;
 struct PropertyWrapperMutability;
 class ProtocolDecl;
 class Requirement;

include/swift/AST/PropertyWrappers.h

@@ -123,6 +123,20 @@ struct PropertyWrapperMutability {
 
 void simple_display(llvm::raw_ostream &os, PropertyWrapperMutability m);
 
+/// Describes whether the reference to a property wrapper instance used for
+/// accessing a wrapped property should be an l-value or not.
+struct PropertyWrapperLValueness {
+  llvm::SmallVector<bool, 1> isLValueForGetAccess;
+  llvm::SmallVector<bool, 1> isLValueForSetAccess;
+
+  bool operator==(PropertyWrapperLValueness other) const {
+    return (isLValueForGetAccess == other.isLValueForGetAccess &&
+            isLValueForSetAccess == other.isLValueForSetAccess);
+  }
+};
+
+void simple_display(llvm::raw_ostream &os, PropertyWrapperLValueness l);
+
 /// Describes the backing property of a property that has an attached wrapper.
 struct PropertyWrapperBackingPropertyInfo {
   /// The backing property.

include/swift/AST/TypeCheckRequests.h

@@ -39,6 +39,7 @@ class DefaultArgumentExpr;
 class GenericParamList;
 class PrecedenceGroupDecl;
 struct PropertyWrapperBackingPropertyInfo;
+struct PropertyWrapperLValueness;
 struct PropertyWrapperMutability;
 class RequirementRepr;
 class SpecializeAttr;
@@ -619,6 +620,26 @@ class PropertyWrapperMutabilityRequest :
   bool isCached() const;
 };
 
+/// Request information about the l-valueness of composed property wrappers.
+class PropertyWrapperLValuenessRequest :
+    public SimpleRequest<PropertyWrapperLValuenessRequest,
+                         Optional<PropertyWrapperLValueness> (VarDecl *),
+                         CacheKind::Cached> {
+public:
+  using SimpleRequest::SimpleRequest;
+
+private:
+  friend SimpleRequest;
+
+  // Evaluation.
+  llvm::Expected<Optional<PropertyWrapperLValueness>>
+  evaluate(Evaluator &evaluator, VarDecl *var) const;
+
+public:
+  // Caching
+  bool isCached() const;
+};
+
 /// Request information about the backing property for properties that have
 /// attached property wrappers.
 class PropertyWrapperBackingPropertyInfoRequest :

include/swift/AST/TypeCheckerTypeIDZone.def

@@ -136,6 +136,9 @@ SWIFT_REQUEST(TypeChecker, PropertyWrapperBackingPropertyInfoRequest,
               NoLocationInfo)
 SWIFT_REQUEST(TypeChecker, PropertyWrapperBackingPropertyTypeRequest,
               Type(VarDecl *), Cached, NoLocationInfo)
+SWIFT_REQUEST(TypeChecker, PropertyWrapperLValuenessRequest,
+              Optional<PropertyWrapperLValueness>(VarDecl *), Cached,
+              NoLocationInfo)
 SWIFT_REQUEST(TypeChecker, PropertyWrapperMutabilityRequest,
               Optional<PropertyWrapperMutability>(VarDecl *), Cached,
               NoLocationInfo)

lib/AST/TypeCheckRequests.cpp

@@ -547,6 +547,11 @@ bool PropertyWrapperMutabilityRequest::isCached() const {
   return !var->getAttrs().isEmpty();
 }
 
+bool PropertyWrapperLValuenessRequest::isCached() const {
+  auto var = std::get<0>(getStorage());
+  return !var->getAttrs().isEmpty();
+}
+
 void swift::simple_display(
     llvm::raw_ostream &out, const PropertyWrapperTypeInfo &propertyWrapper) {
   out << "{ ";
@@ -589,6 +594,14 @@ void swift::simple_display(llvm::raw_ostream &os, PropertyWrapperMutability m) {
   os << "getter " << names[m.Getter] << ", setter " << names[m.Setter];
 }
 
+void swift::simple_display(llvm::raw_ostream &out, PropertyWrapperLValueness l) {
+  out << "is lvalue for get: {";
+  simple_display(out, l.isLValueForGetAccess);
+  out << "}, is lvalue for set: {";
+  simple_display(out, l.isLValueForSetAccess);
+  out << "}";
+}
+
 void swift::simple_display(llvm::raw_ostream &out,
                            const ResilienceExpansion &value) {
   out << value;