Show warning when DU is access without type but RequiredQualifiedAcce…

…ss was set - closes dotnet#95

src/fsharp/infos.fs

@@ -1526,13 +1526,16 @@ type RecdFieldInfo =
 /// Describes an F# use of a union case
 [<NoComparison; NoEquality>]
 type UnionCaseInfo = 
-    | UnionCaseInfo of TypeInst * Tast.UnionCaseRef 
+    | UnionCaseInfo of TypeInst * Tast.UnionCaseRef * bool
 
     /// Get the generic instantiation of the declaring type of the union case
-    member x.TypeInst = let (UnionCaseInfo(tinst,_)) = x in tinst
+    member x.TypeInst = let (UnionCaseInfo(tinst,_,_)) = x in tinst
+
+    /// Determines if the union case usage is deprecated
+    member x.ShowDeprecated = let (UnionCaseInfo(_,_,showDeprecated)) = x in showDeprecated    
 
     /// Get a reference to the F# metadata for the uninstantiated union case
-    member x.UnionCaseRef = let (UnionCaseInfo(_,ucref)) = x in ucref
+    member x.UnionCaseRef = let (UnionCaseInfo(_,ucref,_)) = x in ucref
 
     /// Get the F# metadata for the uninstantiated union case
     member x.UnionCase = x.UnionCaseRef.UnionCase

src/fsharp/nameres.fs

@@ -498,7 +498,7 @@ let AddActivePatternResultTagsToNameEnv (apinfo: PrettyNaming.ActivePatternInfo)
 
 /// Generalize a union case, from Cons --> List<T>.Cons
 let GeneralizeUnionCaseRef (ucref:UnionCaseRef) = 
-    UnionCaseInfo (fst (generalizeTyconRef ucref.TyconRef), ucref)
+    UnionCaseInfo (fst (generalizeTyconRef ucref.TyconRef), ucref, false)
 
 
 /// Add type definitions to the sub-table of the environment indexed by name and arity
@@ -747,14 +747,14 @@ let FreshenTycon (ncenv: NameResolver) m (tcref:TyconRef) =
 
 /// Convert a reference to a union case into a UnionCaseInfo that includes
 /// a fresh set of inference type variables for the type parameters of the union type.
-let FreshenUnionCaseRef (ncenv: NameResolver) m (ucref:UnionCaseRef) = 
+let FreshenUnionCaseRef showDeprecated (ncenv: NameResolver) m (ucref:UnionCaseRef) = 
     let tinst = ncenv.InstantiationGenerator m (ucref.TyconRef.Typars m)
-    UnionCaseInfo(tinst,ucref)
+    UnionCaseInfo(tinst,ucref,showDeprecated)
 
 /// This must be called after fetching unqualified items that may need to be freshened
 let FreshenUnqualifiedItem (ncenv: NameResolver) m res = 
     match res with 
-    | Item.UnionCase (UnionCaseInfo(_,ucref)) -> Item.UnionCase (FreshenUnionCaseRef ncenv m ucref)
+    | Item.UnionCase (UnionCaseInfo(_,ucref,_)) -> Item.UnionCase (FreshenUnionCaseRef false ncenv m ucref)
     | _ -> res
 
 
@@ -1496,7 +1496,7 @@ let TryFindUnionCaseOfType g typ nm =
         let tcref,tinst = destAppTy g typ
         match tcref.GetUnionCaseByName nm with 
         | None -> None
-        | Some ucase -> Some(UnionCaseInfo(tinst,mkNestedUnionCaseRef tcref ucase))
+        | Some ucase -> Some(UnionCaseInfo(tinst,mkNestedUnionCaseRef tcref ucase,false))
     else 
         None
 
@@ -1652,7 +1652,8 @@ let rec ResolveExprLongIdentInModuleOrNamespace (ncenv:NameResolver) nenv (typeN
         match  TryFindTypeWithUnionCase modref id with
         | Some tycon when IsTyconReprAccessible ncenv.amap m ad (modref.MkNestedTyconRef tycon) -> 
             let ucref = mkUnionCaseRef (modref.MkNestedTyconRef tycon) id.idText 
-            let ucinfo = FreshenUnionCaseRef ncenv m ucref
+            let showDeprecated = HasFSharpAttribute ncenv.g ncenv.g.attrib_RequireQualifiedAccessAttribute tycon.Attribs
+            let ucinfo = FreshenUnionCaseRef showDeprecated ncenv m ucref
             success (resInfo,Item.UnionCase ucinfo,rest)
         | _ -> 
         match mty.ExceptionDefinitionsByDemangledName.TryFind(id.idText) with
@@ -1854,7 +1855,8 @@ let rec ResolvePatternLongIdentInModuleOrNamespace (ncenv:NameResolver) nenv num
         | Some tycon when IsTyconReprAccessible ncenv.amap m ad (modref.MkNestedTyconRef tycon) -> 
             let tcref = modref.MkNestedTyconRef tycon
             let ucref = mkUnionCaseRef tcref id.idText
-            let ucinfo = FreshenUnionCaseRef ncenv m ucref
+            let showDeprecated = HasFSharpAttribute ncenv.g ncenv.g.attrib_RequireQualifiedAccessAttribute tycon.Attribs
+            let ucinfo = FreshenUnionCaseRef showDeprecated ncenv m ucref
             success (resInfo,Item.UnionCase ucinfo,rest)
         | _ -> 
         match mty.ExceptionDefinitionsByDemangledName.TryFind(id.idText) with
@@ -2466,7 +2468,7 @@ let ResolveCompletionsInType (ncenv: NameResolver) nenv isApplicableMeth m ad st
             let tc,tinst = destAppTy g typ
             tc.UnionCasesAsRefList 
             |> List.filter (IsUnionCaseUnseen ad g ncenv.amap m >> not)
-            |> List.map (fun ucref ->  Item.UnionCase(UnionCaseInfo(tinst,ucref)))
+            |> List.map (fun ucref ->  Item.UnionCase(UnionCaseInfo(tinst,ucref,false)))
         else []
 
     let einfos = 

src/fsharp/tc.fs

@@ -1877,6 +1877,10 @@ let rec ApplyUnionCaseOrExn (makerForUnionCase,makerForExnTag) m cenv env overal
         mkf,recdFieldTysOfExnDefRef ecref, [ for f in (recdFieldsOfExnDefRef ecref) -> f.Name ]
 
     | Item.UnionCase ucinfo ->   
+        if ucinfo.ShowDeprecated then
+            let message = sprintf "The union type for union case '%s' was definded with the RequireQualifiedAccessAttribute. Include the name of the union type ('%s') in the name you are using.'" ucinfo.Name ucinfo.Tycon.DisplayName
+            warning(Deprecated(message,m))
+
         let ucref = ucinfo.UnionCaseRef 
         CheckUnionCaseAttributes cenv.g ucref m  |> CommitOperationResult
         CheckUnionCaseAccessible cenv.amap m ad ucref |> ignore
@@ -7870,7 +7874,7 @@ and TcItemThen cenv overallTy env tpenv (item,mItem,rest,afterOverloadResolution
               | _ ->
                   let ucref = mkChoiceCaseRef cenv.g mItem aparity n
                   let _,_,tinst,_ = infoOfTyconRef mItem ucref.TyconRef
-                  let ucinfo = UnionCaseInfo(tinst,ucref)
+                  let ucinfo = UnionCaseInfo(tinst,ucref,false)
                   ApplyUnionCaseOrExnTypes mItem cenv env ucaseAppTy (Item.UnionCase ucinfo)
           | _ -> 
               ApplyUnionCaseOrExnTypes mItem cenv env ucaseAppTy item
@@ -14020,7 +14024,7 @@ module EstablishTypeDefinitionCores = begin
                 let nenv = envinner.NameEnv
                 // Constructors should be visible from IntelliSense, so add fake names for them 
                 for unionCase in unionCases do
-                    let info = UnionCaseInfo(thisTyInst,mkUnionCaseRef thisTyconRef unionCase.Id.idText)
+                    let info = UnionCaseInfo(thisTyInst,mkUnionCaseRef thisTyconRef unionCase.Id.idText,false)
                     let nenv' = AddFakeNameToNameEnv unionCase.Id.idText nenv (Item.UnionCase info) 
                     // Report to both - as in previous function
                     let item = Item.UnionCase info

src/fsharp/vs/ServiceDeclarations.fs

@@ -511,7 +511,7 @@ module internal ItemDescriptionsImpl =
               | Wrap(Item.Value vref1 | Item.CustomBuilder (_,vref1)), Wrap(Item.Value vref2 | Item.CustomBuilder (_,vref2)) -> valRefEq g vref1 vref2
               | Wrap(Item.ActivePatternCase(APElemRef(_apinfo1, vref1, idx1))), Wrap(Item.ActivePatternCase(APElemRef(_apinfo2, vref2, idx2))) ->
                   idx1 = idx2 && valRefEq g vref1 vref2
-              | Wrap(Item.UnionCase(UnionCaseInfo(_, ur1))), Wrap(Item.UnionCase(UnionCaseInfo(_, ur2))) -> g.unionCaseRefEq ur1 ur2
+              | Wrap(Item.UnionCase(UnionCaseInfo(_, ur1,_))), Wrap(Item.UnionCase(UnionCaseInfo(_, ur2,false))) -> g.unionCaseRefEq ur1 ur2
               | Wrap(Item.RecdField(RecdFieldInfo(_, RFRef(tcref1, n1)))), Wrap(Item.RecdField(RecdFieldInfo(_, RFRef(tcref2, n2)))) -> 
                   (tyconRefEq g tcref1 tcref2) && (n1 = n2) // there is no direct function as in the previous case
               | Wrap(Item.Property(_, pi1s)), Wrap(Item.Property(_, pi2s)) -> 
@@ -542,7 +542,7 @@ module internal ItemDescriptionsImpl =
               | Wrap(Item.Value vref | Item.CustomBuilder (_,vref)) -> hash vref.LogicalName
               | Wrap(Item.ActivePatternCase(APElemRef(_apinfo, vref, idx))) -> hash (vref.LogicalName, idx)
               | Wrap(Item.ExnCase(tcref)) -> hash tcref.Stamp
-              | Wrap(Item.UnionCase(UnionCaseInfo(_, UCRef(tcref, n)))) -> hash(tcref.Stamp, n)
+              | Wrap(Item.UnionCase(UnionCaseInfo(_, UCRef(tcref, n),false))) -> hash(tcref.Stamp, n)
               | Wrap(Item.RecdField(RecdFieldInfo(_, RFRef(tcref, n)))) -> hash(tcref.Stamp, n)
               | Wrap(Item.Event evt) -> evt.ComputeHashCode()
               | Wrap(Item.Property(_name, pis)) -> hash (pis |> List.map (fun pi -> pi.ComputeHashCode()))