Improving the DuplicateAttribute reassignment

Author: Visckmart

lib/Parse/ParseDecl.cpp

@@ -2987,14 +2987,13 @@ ParserStatus Parser::parseNewDeclAttribute(DeclAttributes &Attributes,
       // Normal access control attribute.
       AttrRange = Loc;
 
-      
       if (!DiscardAttribute) {
         Attributes.add(new (Context) AccessControlAttr(AtLoc, Loc, access));
         break;
       }
 
       if (access != cast<AccessControlAttr>(*DuplicateAttribute).getAccess()) {
-        // Diagnose if there is already an access control attribute on
+        // Diagnose if there's already an access control attribute on
         // this declaration with a different access level.
         diagnose(Loc, diag::multiple_access_level_modifiers)
           .highlight(AttrRange);
@@ -3036,15 +3035,17 @@ ParserStatus Parser::parseNewDeclAttribute(DeclAttributes &Attributes,
       return makeParserSuccess();
     }
 
+    // Check for duplicate setter access control attributes.
     DuplicateAttribute = Attributes.getAttribute<SetterAccessAttr>();
-    
-    if (!DuplicateAttribute) {
+    DiscardAttribute = DuplicateAttribute != nullptr;
+        
+    if (!DiscardAttribute) {
       Attributes.add(new (Context) SetterAccessAttr(AtLoc, AttrRange, access));
       break;
     }
 
     if (access != cast<SetterAccessAttr>(*DuplicateAttribute).getAccess()) {
-      // Diagnose if there is already an access control attribute on
+      // Diagnose if there's already an access control attribute on
       // this declaration with a different access level.
       diagnose(Loc, diag::multiple_access_level_modifiers)
         .highlight(AttrRange);