Flatten always-on LanguageFeature.NameOf flag

src/Compiler/Checking/CheckPatterns.fs

@@ -628,8 +628,7 @@ and TcPatLongIdentNewDef warnOnUpperForId warnOnUpper (cenv: cenv) env ad valRep
     | [] ->
         TcPat warnOnUpperForId cenv env valReprInfo vFlags patEnv ty (mkSynPatVar vis id)
 
-    | [arg]
-        when g.langVersion.SupportsFeature LanguageFeature.NameOf && IsNameOf cenv env ad m id ->
+    | [arg] when IsNameOf cenv env ad m id ->
         match TcNameOfExpr cenv env tpenv (ConvSynPatToSynExpr arg) with
         | Expr.Const(Const.String s, m, _) ->
             // Record the resolution of the `nameof` usage so that we can classify it correctly later.

src/Compiler/Checking/Expressions/CheckExpressions.fs

@@ -8990,7 +8990,7 @@ and TcApplicationThen (cenv: cenv) (overallTy: OverallTy) env tpenv mExprAndArg
             checkHighPrecedenceFunctionApplicationToList [synArg] atomicFlag mExprAndArg
 
         match leftExpr with
-        | ApplicableExpr(expr=NameOfExpr g _) when g.langVersion.SupportsFeature LanguageFeature.NameOf ->
+        | ApplicableExpr(expr=NameOfExpr g _) ->
             let replacementExpr = TcNameOfExpr cenv env tpenv synArg
             TcDelayed cenv overallTy env tpenv mExprAndArg (ApplicableExpr(cenv, replacementExpr, true, None)) g.string_ty ExprAtomicFlag.Atomic delayed
         | _ ->
@@ -9726,7 +9726,7 @@ and TcValueItemThen cenv overallTy env vref tpenv mItem mItemIdent afterResoluti
         //   - it isn't a VSlotDirectCall (uses of base values do not take type arguments
         // Allow `nameof<'T>` for a generic parameter
         match vref with
-        | _ when isNameOfValRef g vref && g.langVersion.SupportsFeature LanguageFeature.NameOf ->
+        | _ when isNameOfValRef g vref ->
             // Record the resolution of the `nameof` usage so that we can classify it correctly later.
             do
                 match afterResolution with

src/Compiler/Checking/NameResolution.fs

@@ -60,7 +60,6 @@ type NameResolver(g: TcGlobals,
     member nr.g = g
     member nr.amap = amap
     member nr.InfoReader = infoReader
-    member nr.languageSupportsNameOf = g.langVersion.SupportsFeature LanguageFeature.NameOf
 
 //-------------------------------------------------------------------------
 // Helpers for unionconstrs and recdfields
@@ -3468,15 +3467,6 @@ let rec ResolveExprLongIdentPrim sink (ncenv: NameResolver) first fullyQualified
 
     let lookupKind = LookupKind.Expr LookupIsInstance.No
 
-    let canSuggestThisItem (item:Item) =
-        // All items can be suggested except nameof when it comes from FSharp.Core.dll and the nameof feature is not enabled
-        match item with
-        | Item.Value v ->
-            let isNameOfOperator = valRefEq ncenv.g ncenv.g.nameof_vref v
-            if isNameOfOperator && not (ncenv.g.langVersion.SupportsFeature LanguageFeature.NameOf) then false
-            else true
-        | _ -> true
-
     if first && id.idText = MangledGlobalName then
         match rest with
         | [] ->
@@ -3515,15 +3505,7 @@ let rec ResolveExprLongIdentPrim sink (ncenv: NameResolver) first fullyQualified
 
                 | true, res ->
                     let fresh = ResolveUnqualifiedItem ncenv nenv m res
-                    match fresh with
-                    | Item.Value value ->
-                        let isNameOfOperator = valRefEq ncenv.g ncenv.g.nameof_vref value
-                        if isNameOfOperator && not ncenv.languageSupportsNameOf then
-                            // Do not resolve `nameof` if the feature is unsupported, even if it is FSharp.Core
-                            None
-                         else
-                            Some (emptyEnclosingTypeInst, fresh, rest)
-                    | _ -> Some (emptyEnclosingTypeInst, fresh, rest)
+                    Some (emptyEnclosingTypeInst, fresh, rest)
                 | _ ->
                     None
 
@@ -3574,8 +3556,7 @@ let rec ResolveExprLongIdentPrim sink (ncenv: NameResolver) first fullyQualified
 
                     let suggestNamesAndTypes (addToBuffer: string -> unit) =
                         for e in nenv.eUnqualifiedItems do
-                            if canSuggestThisItem e.Value then
-                                addToBuffer e.Value.DisplayName
+                            addToBuffer e.Value.DisplayName
 
                         for e in nenv.TyconsByDemangledNameAndArity fullyQualified do
                             if IsEntityAccessible ncenv.amap m ad e.Value then
@@ -3671,8 +3652,7 @@ let rec ResolveExprLongIdentPrim sink (ncenv: NameResolver) first fullyQualified
                                 addToBuffer tcref.DisplayName
 
                         for KeyValue(_,item) in nenv.eUnqualifiedItems do
-                            if canSuggestThisItem item then
-                                addToBuffer item.DisplayName
+                            addToBuffer item.DisplayName
 
                       match innerSearch with
                       | Exception (UndefinedName(0, _, id1, suggestionsF)) when equals id.idRange id1.idRange ->
@@ -4739,9 +4719,7 @@ let IsUnionCaseUnseen ad g amap m allowObsolete (ucref: UnionCaseRef) =
 
 let ItemIsUnseen ad g amap m allowObsolete item =
     match item with
-    | Item.Value x -> 
-        let isUnseenNameOfOperator = valRefEq g g.nameof_vref x && not (g.langVersion.SupportsFeature LanguageFeature.NameOf)
-        isUnseenNameOfOperator || IsValUnseen ad g m allowObsolete x
+    | Item.Value x -> IsValUnseen ad g m allowObsolete x
     | Item.UnionCase(x, _) -> IsUnionCaseUnseen ad g amap m allowObsolete x.UnionCaseRef
     | Item.ExnCase x -> IsTyconUnseen ad g amap m allowObsolete x
     | Item.ILField finfo -> not allowObsolete && ILFieldInfoIsUnseen finfo

src/Compiler/Checking/NameResolution.fsi

@@ -30,8 +30,6 @@ type NameResolver =
 
     member g: TcGlobals
 
-    member languageSupportsNameOf: bool
-
 /// Get the active pattern elements defined in a module, if any. Cache in the slot in the module type.
 val ActivePatternElemsOfModuleOrNamespace: g: TcGlobals -> ModuleOrNamespaceRef -> NameMap<ActivePatternElemRef>
 

src/Compiler/FSComp.txt

@@ -1559,7 +1559,6 @@ optsAlwaysInline,"Always inline 'inline' functions"
 nativeResourceFormatError,"Stream does not begin with a null resource and is not in '.RES' format."
 nativeResourceHeaderMalformed,"Resource header beginning at offset %s is malformed."
 formatDashItem," - %s"
-featureNameOf,"nameof"
 featureDotlessFloat32Literal,"dotless float32 literal"
 featurePackageManagement,"package management"
 featureFromEndSlicing,"from-end slicing"
@@ -1788,7 +1787,7 @@ featurePreprocessorElif,"#elif preprocessor directive"
 featureExtensionConstraintSolutions,"Allow extension members to participate in SRTP constraint resolution"
 featureErrorOnBitwiseOpsOnNonIntegralEnums,"Error when bitwise operators are used on enums whose underlying type is not an integer type (e.g. char)."
 3880,optsLangVersionOutOfSupport,"Language version '%s' is out of support. The last .NET SDK supporting it is available at https://dotnet.microsoft.com/en-us/download/dotnet/%s"
-3881,optsUnrecognizedLanguageFeature,"Unrecognized language feature name: '%s'. Use a valid feature name such as 'NameOf' or 'StringInterpolation'."
+3881,optsUnrecognizedLanguageFeature,"Unrecognized language feature name: '%s'. Use a valid feature name such as 'StringInterpolation' or 'FromEndSlicing'."
 3882,lexHashElifMustBeFirst,"#elif directive must appear as the first non-whitespace character on a line"
 3883,lexHashElifMustHaveIdent,"#elif directive should be immediately followed by an identifier"
 3884,tcFunctionValueUsedAsInterpolatedStringArg,"This expression is a function value. When used in an interpolated string it will be formatted using its 'ToString' method, which is likely not the intended behavior. Consider applying the function to its arguments."

src/Compiler/Facilities/LanguageFeatures.fs

@@ -16,7 +16,6 @@ module internal FSharp.Compiler.Features
 
 [<RequireQualifiedAccess>]
 type LanguageFeature =
-    | NameOf
     | DotlessFloat32Literal
     | PackageManagement
     | FromEndSlicing
@@ -142,7 +141,6 @@ type LanguageVersion(versionText, ?disabledFeaturesArray: LanguageFeature array)
                 LanguageFeature.DefaultInterfaceMemberConsumption, languageVersion50
                 LanguageFeature.PackageManagement, languageVersion50
                 LanguageFeature.WitnessPassing, languageVersion50
-                LanguageFeature.NameOf, languageVersion50
                 LanguageFeature.StringInterpolation, languageVersion50
 
                 // F# 6.0
@@ -328,7 +326,6 @@ type LanguageVersion(versionText, ?disabledFeaturesArray: LanguageFeature array)
     /// Get a string name for the given feature.
     static member GetFeatureString feature =
         match feature with
-        | LanguageFeature.NameOf -> FSComp.SR.featureNameOf ()
         | LanguageFeature.DotlessFloat32Literal -> FSComp.SR.featureDotlessFloat32Literal ()
         | LanguageFeature.PackageManagement -> FSComp.SR.featurePackageManagement ()
         | LanguageFeature.FromEndSlicing -> FSComp.SR.featureFromEndSlicing ()

src/Compiler/Facilities/LanguageFeatures.fsi

@@ -6,7 +6,6 @@ module internal FSharp.Compiler.Features
 /// LanguageFeature enumeration
 [<RequireQualifiedAccess>]
 type LanguageFeature =
-    | NameOf
     | DotlessFloat32Literal
     | PackageManagement
     | FromEndSlicing

src/Compiler/TypedTree/TypedTreeOps.Transforms.fs

@@ -2351,7 +2351,7 @@ module internal ConstantEvaluation =
             | UncheckedDefaultOfExpr g _
             | SizeOfExpr g _
             | TypeOfExpr g _ -> true
-            | NameOfExpr g _ when g.langVersion.SupportsFeature LanguageFeature.NameOf -> true
+            | NameOfExpr g _ -> true
             // All others are not simple constant expressions
             | _ -> false