Sema: make StructuralTypeRequest use CacheKind::Cached

Author: xymus

include/swift/AST/ASTTypeIDZone.def

@@ -20,3 +20,4 @@ SWIFT_TYPEID(Type)
 SWIFT_TYPEID(PropertyDelegateBackingPropertyInfo)
 SWIFT_TYPEID(PropertyDelegateTypeInfo)
 SWIFT_TYPEID_NAMED(CustomAttr *, CustomAttr)
+SWIFT_TYPEID_NAMED(TypeAliasDecl *, TypeAliasDecl)

include/swift/AST/ASTTypeIDs.h

@@ -26,6 +26,7 @@ struct PropertyDelegateBackingPropertyInfo;
 struct PropertyDelegateTypeInfo;
 class Type;
 class VarDecl;
+class TypeAliasDecl;
 
 #define SWIFT_AST_TYPEID_ZONE 1
 

include/swift/AST/TypeCheckRequests.h

@@ -551,7 +551,7 @@ class PropertyDelegateBackingPropertyInfoRequest :
 /// Retrieve the structural type of an alias type.
 class StructuralTypeRequest :
     public SimpleRequest<StructuralTypeRequest,
-                         CacheKind::SeparatelyCached,
+                         CacheKind::Cached,
                          Type,
                          TypeAliasDecl*> {
 public:
@@ -568,13 +568,10 @@ class StructuralTypeRequest :
   void diagnoseCycle(DiagnosticEngine &diags) const;
   void noteCycleStep(DiagnosticEngine &diags) const;
 
-  // Separate caching.
-  bool isCached() const { return true; };
-  Optional<Type> getCachedResult() const;
-  void cacheResult(Type value) const;
+  // Caching.
+  bool isCached() const { return true; }
 };
 
-
 // Allow AnyValue to compare two Type values, even though Type doesn't
 // support ==.
 template<>

lib/AST/TypeCheckRequests.cpp

@@ -672,15 +672,3 @@ void StructuralTypeRequest::diagnoseCycle(DiagnosticEngine &diags) const {
 void StructuralTypeRequest::noteCycleStep(DiagnosticEngine &diags) const {
   diags.diagnose(SourceLoc(), diag::circular_reference_through);
 }
-
-Optional<Type> StructuralTypeRequest::getCachedResult() const {
-  auto decl = std::get<0>(getStorage());
-  if (decl->getUnderlyingTypeLoc().getType())
-    return decl->getUnderlyingTypeLoc().getType();
-  return None;
-}
-
-void StructuralTypeRequest::cacheResult(Type value) const {
-  auto decl = std::get<0>(getStorage());
-  decl->getUnderlyingTypeLoc().setType(value);
-}