Chore :: Remove #IF NULLABLE, MaybeNull and other leftovers from bootstrap times of Nullable feature

src/Compiler/AbstractIL/ilnativeres.fs

@@ -27,7 +27,7 @@ type WORD = uint16
 
 let inline WORD s = uint16 s
 
-type ResourceException(name: string, ?inner: Exception MaybeNull) =
+type ResourceException(name: string, ?inner: (Exception | null)) =
     inherit Exception(name, Option.toObj inner)
 
 type RESOURCE_STRING() =

src/Compiler/AbstractIL/ilread.fs

@@ -226,7 +226,7 @@ type WeakByteFile(fileName: string, chunk: (int * int) option) =
     let fileStamp = FileSystem.GetLastWriteTimeShim fileName
 
     /// The weak handle to the bytes for the file
-    let weakBytes = WeakReference<byte[] MaybeNull>(null)
+    let weakBytes = WeakReference<byte[] | null>(null)
 
     member _.FileName = fileName
 

src/Compiler/AbstractIL/ilreflect.fs

@@ -550,7 +550,7 @@ let emEnv0 =
         delayedFieldInits = []
     }
 
-let envBindTypeRef emEnv (tref: ILTypeRef) (typT: Type MaybeNull, typB, typeDef) =
+let envBindTypeRef emEnv (tref: ILTypeRef) (typT: Type | null, typB, typeDef) =
     match typT with
     | Null -> failwithf "binding null type in envBindTypeRef: %s\n" tref.Name
     | NonNull typT ->
@@ -697,7 +697,7 @@ let rec convTypeSpec cenv emEnv preferCreated (tspec: ILTypeSpec) =
     let typT = convTypeRef cenv emEnv preferCreated tspec.TypeRef
     let tyargs = List.map (convTypeAux cenv emEnv preferCreated) tspec.GenericArgs
 
-    let res: Type MaybeNull =
+    let res: Type | null =
         match isNil tyargs, typT.IsGenericType with
         | _, true -> typT.MakeGenericType(List.toArray tyargs)
         | true, false -> typT
@@ -1013,7 +1013,7 @@ let queryableTypeGetMethod cenv emEnv parentT (mref: ILMethodRef) : MethodInfo =
     else
         queryableTypeGetMethodBySearch cenv emEnv parentT mref
 
-let nonQueryableTypeGetMethod (parentTI: Type) (methInfo: MethodInfo) : MethodInfo MaybeNull =
+let nonQueryableTypeGetMethod (parentTI: Type) (methInfo: MethodInfo) : MethodInfo | null =
     if
         (parentTI.IsGenericType
          && not (equalTypes parentTI (getTypeConstructor parentTI)))
@@ -1102,7 +1102,7 @@ let queryableTypeGetConstructor cenv emEnv (parentT: Type) (mref: ILMethodRef) =
         )
     | NonNull res -> res
 
-let nonQueryableTypeGetConstructor (parentTI: Type) (consInfo: ConstructorInfo) : ConstructorInfo MaybeNull =
+let nonQueryableTypeGetConstructor (parentTI: Type) (consInfo: ConstructorInfo) : ConstructorInfo | null =
     if parentTI.IsGenericType then
         TypeBuilder.GetConstructor(parentTI, consInfo)
     else

src/Compiler/AbstractIL/ilsign.fs

@@ -171,7 +171,7 @@ let RSAParametersFromBlob blob keyType =
     key.D <- reader.ReadBigInteger byteLen
     key
 
-let validateRSAField (field: byte array MaybeNull) expected (name: string) =
+let validateRSAField (field: byte array | null) expected (name: string) =
     match field with
     | Null -> ()
     | NonNull field ->
@@ -237,7 +237,7 @@ let toCLRKeyBlob (rsaParameters: RSAParameters) (algId: int) : byte array =
 
             buffer
 
-        let safeArrayRev (buffer: _ MaybeNull) =
+        let safeArrayRev (buffer: _ | null) =
             match buffer with
             | Null -> Array.empty<byte>
             | NonNull buffer -> buffer |> Array.rev

src/Compiler/Checking/AccessibilityLogic.fs

@@ -374,7 +374,7 @@ let IsPropInfoAccessible g amap m ad = function
     | ProvidedProp (amap, tppi, m) as pp-> 
         let access = 
             let a = tppi.PUntaint((fun ppi -> 
-                let tryGetILAccessForProvidedMethodBase (mi : ProvidedMethodInfo MaybeNull) =
+                let tryGetILAccessForProvidedMethodBase (mi : (ProvidedMethodInfo | null)) =
                     match mi with
                     | Null -> None
                     | NonNull mi -> 

src/Compiler/Checking/MethodCalls.fs

@@ -1871,7 +1871,7 @@ module ProvidedMethodCalls =
              allArgs: Exprs,
              paramVars: Tainted<ProvidedVar>[],
              g, amap, mut, isProp, isSuperInit, m,
-             expr: Tainted<ProvidedExpr MaybeNull>) = 
+             expr: Tainted<(ProvidedExpr | null)>) = 
 
         let varConv =
             // note: Assuming the size based on paramVars
@@ -1881,8 +1881,8 @@ module ProvidedMethodCalls =
                 dict.Add(v, (None, e))
             dict
 
-        let rec exprToExprAndWitness top (ea: Tainted<ProvidedExpr MaybeNull>) =
-            let fail() = error(Error(FSComp.SR.etUnsupportedProvidedExpression(ea.PUntaint((fun etree -> etree.UnderlyingExpressionString), m)), m))
+        let rec exprToExprAndWitness top (ea: Tainted<(ProvidedExpr | null)>) =
+            let fail() = error(Error(FSComp.SR.etUnsupportedProvidedExpression(ea.PUntaint((fun etree -> match etree with null -> "<null>" | e -> e.UnderlyingExpressionString), m)), m))
             match ea with
             | Tainted.Null -> error(Error(FSComp.SR.etNullProvidedExpression(ea.TypeProviderDesignation), m))
             | Tainted.NonNull ea ->

src/Compiler/Checking/import.fs

@@ -38,7 +38,7 @@ type AssemblyLoader =
     /// Get a flag indicating if an assembly is a provided assembly, plus the
     /// table of information recording remappings from type names in the provided assembly to type
     /// names in the statically linked, embedded assembly.
-    abstract GetProvidedAssemblyInfo : CompilationThreadToken * range * Tainted<ProvidedAssembly MaybeNull> -> bool * ProvidedAssemblyStaticLinkingMap option
+    abstract GetProvidedAssemblyInfo : CompilationThreadToken * range * Tainted<(ProvidedAssembly | null)> -> bool * ProvidedAssemblyStaticLinkingMap option
 
     /// Record a root for a [<Generate>] type to help guide static linking & type relocation
     abstract RecordGeneratedTypeRoot : ProviderGeneratedType -> unit

src/Compiler/Checking/import.fsi

@@ -28,7 +28,7 @@ type AssemblyLoader =
     /// table of information recording remappings from type names in the provided assembly to type
     /// names in the statically linked, embedded assembly.
     abstract GetProvidedAssemblyInfo:
-        CompilationThreadToken * range * Tainted<ProvidedAssembly MaybeNull> ->
+        CompilationThreadToken * range * Tainted<(ProvidedAssembly | null)> ->
             bool * ProvidedAssemblyStaticLinkingMap option
 
     /// Record a root for a [<Generate>] type to help guide static linking & type relocation

src/Compiler/Checking/infos.fs

@@ -341,7 +341,7 @@ let CrackParamAttribsInfo g (ty: TType, argInfo: ArgReprInfo) =
 type ILFieldInit with
 
     /// Compute the ILFieldInit for the given provided constant value for a provided enum type.
-    static member FromProvidedObj m (v: obj MaybeNull) =
+    static member FromProvidedObj m (v: obj | null) =
         match v with
         | Null -> ILFieldInit.Null
         | NonNull v ->
@@ -393,8 +393,8 @@ let OptionalArgInfoOfProvidedParameter (amap: ImportMap) m (provParam : Tainted<
         NotOptional
 
 /// Compute the ILFieldInit for the given provided constant value for a provided enum type.
-let GetAndSanityCheckProviderMethod m (mi: Tainted<'T :> ProvidedMemberInfo>) (get : 'T -> ProvidedMethodInfo MaybeNull) err = 
-    match mi.PApply((fun mi -> (get mi :> ProvidedMethodBase MaybeNull)),m) with 
+let GetAndSanityCheckProviderMethod m (mi: Tainted<'T :> ProvidedMemberInfo>) (get : 'T -> (ProvidedMethodInfo | null)) err = 
+    match mi.PApply((fun mi -> (get mi :> (ProvidedMethodBase | null))),m) with 
     | Tainted.Null -> error(Error(err(mi.PUntaint((fun mi -> mi.Name),m),mi.PUntaint((fun mi -> (nonNull mi.DeclaringType).Name), m)), m))
     | Tainted.NonNull meth -> meth
 

src/Compiler/CodeGen/IlxGen.fs

@@ -12194,7 +12194,7 @@ let LookupGeneratedValue (cenv: cenv) (ctxt: ExecutionContext) eenv (v: Val) =
                 if hasLiteralAttr then
                     let staticTy = ctxt.LookupTypeRef fspec.DeclaringTypeRef
                     // Checked: This FieldInfo (FieldBuilder) supports GetValue().
-                    (!!staticTy.GetField(fspec.Name)).GetValue(null: obj MaybeNull)
+                    (!!staticTy.GetField(fspec.Name)).GetValue(null: obj | null)
                 else
                     let staticTy = ctxt.LookupTypeRef ilContainerTy.TypeRef
                     // We can't call .Invoke on the ILMethodRef's MethodInfo,

src/Compiler/DependencyManager/DependencyProvider.fsi

@@ -106,11 +106,11 @@ type DependencyProvider =
 
     /// Returns a formatted help messages for registered dependencymanagers for the host to present
     member GetRegisteredDependencyManagerHelpText:
-        string seq * string MaybeNull * sdkDirOverride: string option * ResolvingErrorReport -> string[]
+        string seq * (string | null) * sdkDirOverride: string option * ResolvingErrorReport -> string[]
 
     /// Clear the DependencyManager results caches
     member ClearResultsCache:
-        string seq * string MaybeNull * sdkDirOverride: string option * ResolvingErrorReport -> unit
+        string seq * (string | null) * sdkDirOverride: string option * ResolvingErrorReport -> unit
 
     /// Returns a formatted error message for the host to present
     member CreatePackageManagerUnknownError:
@@ -123,7 +123,7 @@ type DependencyProvider =
         packageManagerTextLines: (string * string) seq *
         reportError: ResolvingErrorReport *
         executionTfm: string *
-        [<Optional; DefaultParameterValue(null: string MaybeNull)>] executionRid: string MaybeNull *
+        [<Optional; DefaultParameterValue(null: (string | null))>] executionRid: (string | null) *
         [<Optional; DefaultParameterValue("")>] implicitIncludeDir: string *
         [<Optional; DefaultParameterValue("")>] mainScriptName: string *
         [<Optional; DefaultParameterValue("")>] fileName: string *

src/Compiler/Driver/CompilerImports.fs

@@ -1455,7 +1455,7 @@ and [<Sealed>] TcImports
         | _ -> None
 
 #if !NO_TYPEPROVIDERS
-    member tcImports.GetProvidedAssemblyInfo(ctok, m, assembly: Tainted<ProvidedAssembly MaybeNull>) =
+    member tcImports.GetProvidedAssemblyInfo(ctok, m, assembly: Tainted<(ProvidedAssembly | null)>) =
         match assembly with
         | Tainted.Null -> false, None
         | Tainted.NonNull assembly ->

src/Compiler/Driver/FxResolver.fs

@@ -58,12 +58,12 @@ type internal FxResolver
             let mutable errorslock = obj
             let mutable outputlock = obj
 
-            let outputDataReceived (message: string MaybeNull) =
+            let outputDataReceived (message: string | null) =
                 match message with
                 | Null -> ()
                 | NonNull message -> lock outputlock (fun () -> outputList.Add(message))
 
-            let errorDataReceived (message: string MaybeNull) =
+            let errorDataReceived (message: string | null) =
                 match message with
                 | Null -> ()
                 | NonNull message -> lock errorslock (fun () -> errorsList.Add(message))

src/Compiler/FSharp.Compiler.Service.fsproj

@@ -101,7 +101,7 @@
   </ItemGroup>
 
   <ItemGroup>
-    <Compile Include="Utilities\NullnessShims.fs" />
+    <Compile Include="Utilities\NullHelpers.fs" />
     <EmbeddedText Include="FSComp.txt">
       <Link>FSComp.txt</Link>
     </EmbeddedText>

src/Compiler/Facilities/CompilerLocation.fs

@@ -22,7 +22,7 @@ module internal FSharpEnvironment =
 
     let FSharpProductName = UtilsStrings.SR.buildProductName (FSharpBannerVersion)
 
-    let versionOf<'t> : MaybeNull<string> =
+    let versionOf<'t> : (string | null) =
         match typeof<'t>.Assembly.GetName().Version with
         | null -> null
         | v -> v.ToString()

src/Compiler/Facilities/SimulatedMSBuildReferenceResolver.fs

@@ -69,7 +69,7 @@ let private SimulatedMSBuildResolver =
         let isDesktop = typeof<int>.Assembly.GetName().Name = "mscorlib"
 
         if isDesktop then
-            match (System.Runtime.InteropServices.RuntimeEnvironment.GetRuntimeDirectory(): string MaybeNull) with
+            match (System.Runtime.InteropServices.RuntimeEnvironment.GetRuntimeDirectory(): string | null) with
             | null -> []
             | x -> [ x ]
         else

src/Compiler/Interactive/fsi.fs

@@ -376,7 +376,7 @@ type ILMultiInMemoryAssemblyEmitEnv
         let typT = convTypeRef tref
         let tyargs = List.map convTypeAux tspec.GenericArgs
 
-        let res: Type MaybeNull =
+        let res: Type | null =
             match isNil tyargs, typT.IsGenericType with
             | _, true -> typT.MakeGenericType(List.toArray tyargs)
             | true, false -> typT
@@ -974,11 +974,15 @@ type internal FsiCommandLineOptions(fsi: FsiEvaluationSessionHostConfig, argv: s
     let executableFileNameWithoutExtension =
         lazy
             let getFsiCommandLine () =
-                let fileNameWithoutExtension (path: string MaybeNull) = Path.GetFileNameWithoutExtension(path)
+                let fileNameWithoutExtension (path: string | null) = Path.GetFileNameWithoutExtension(path)
 
                 let currentProcess = Process.GetCurrentProcess()
                 let mainModule = currentProcess.MainModule
-                let processFileName = fileNameWithoutExtension (mainModule ^ _.FileName)
+
+                let processFileName =
+                    match mainModule with
+                    | null -> null
+                    | m -> fileNameWithoutExtension m.FileName
 
                 let commandLineExecutableFileName =
                     try
@@ -2468,7 +2472,7 @@ type internal FsiDynamicCompiler
     member _.DynamicAssemblies = dynamicAssemblies.ToArray()
 
     member _.FindDynamicAssembly(name, useFullName: bool) =
-        let getName (assemblyName: AssemblyName) : string MaybeNull =
+        let getName (assemblyName: AssemblyName) : string | null =
             if useFullName then
                 assemblyName.FullName
             else
@@ -3316,7 +3320,7 @@ type internal MagicAssemblyResolution() =
             fsiDynamicCompiler: FsiDynamicCompiler,
             fsiConsoleOutput: FsiConsoleOutput,
             fullAssemName: string
-        ) : Assembly MaybeNull =
+        ) : Assembly | null =
 
         try
             // Grab the name of the assembly
@@ -3472,7 +3476,7 @@ type internal MagicAssemblyResolution() =
             fsiDynamicCompiler: FsiDynamicCompiler,
             fsiConsoleOutput: FsiConsoleOutput,
             fullAssemName: string
-        ) : Assembly MaybeNull =
+        ) : Assembly | null =
 
         //Eliminate recursive calls to Resolve which can happen via our callout to msbuild resolution
         if MagicAssemblyResolution.resolving then
@@ -3534,7 +3538,7 @@ type FsiStdinLexerProvider
         lexResourceManager: LexResourceManager
     ) =
 
-    let LexbufFromLineReader (fsiStdinSyphon: FsiStdinSyphon) (readF: unit -> string MaybeNull) =
+    let LexbufFromLineReader (fsiStdinSyphon: FsiStdinSyphon) (readF: unit -> string | null) =
         UnicodeLexing.FunctionAsLexbuf(
             true,
             tcConfigB.langVersion,
@@ -3578,7 +3582,7 @@ type FsiStdinLexerProvider
     // Reading stdin as a lex stream
     //----------------------------------------------------------------------------
 
-    let removeZeroCharsFromString (str: string MaybeNull) : string MaybeNull =
+    let removeZeroCharsFromString (str: string | null) : string | null =
         match str with
         | Null -> str
         | NonNull str ->

src/Compiler/Service/QuickParse.fs

@@ -180,7 +180,7 @@ module QuickParse =
                         let pos = r + MagicalAdjustmentConstant
                         Some(ident, pos, false))
 
-    let GetCompleteIdentifierIslandImpl (lineStr: string MaybeNull) (index: int) : (string * int * bool) option =
+    let GetCompleteIdentifierIslandImpl (lineStr: string | null) (index: int) : (string * int * bool) option =
         match lineStr with
         | Null -> None
         | NonNull lineStr -> GetCompleteIdentifierIslandImplAux lineStr index
@@ -208,7 +208,7 @@ module QuickParse =
     /// a call to `DeclItemsForNamesAtPosition` for intellisense. This will
     /// allow us to use find the correct qualified items rather than resorting
     /// to the more expensive and less accurate environment lookup.
-    let GetCompleteIdentifierIsland (tolerateJustAfter: bool) (lineStr: string MaybeNull) (index: int) : (string * int * bool) option =
+    let GetCompleteIdentifierIsland (tolerateJustAfter: bool) (lineStr: string | null) (index: int) : (string * int * bool) option =
         if String.IsNullOrEmpty lineStr then
             None
         else
@@ -274,7 +274,7 @@ module QuickParse =
             let result = InResidue(index, index)
             result
 
-    let GetPartialLongName (lineStr: string MaybeNull, index: int) =
+    let GetPartialLongName (lineStr: string | null, index: int) =
         match lineStr with
         | Null -> defaultName
         | NonNull lineStr -> GetPartialLongNameAux(lineStr, index)
@@ -429,7 +429,7 @@ module QuickParse =
                     QualifyingIdents = plid
                 }
 
-    let GetPartialLongNameEx (lineStr: string MaybeNull, index: int) : PartialLongName =
+    let GetPartialLongNameEx (lineStr: string | null, index: int) : PartialLongName =
         match lineStr with
         | Null -> PartialLongName.Empty(index)
         | NonNull lineStr -> GetPartialLongNameExAux(lineStr, index)

src/Compiler/Service/QuickParse.fsi

@@ -73,14 +73,14 @@ module public QuickParse =
     /// allow us to use find the correct qualified items rather than resorting
     /// to the more expensive and less accurate environment lookup.
     val GetCompleteIdentifierIsland:
-        tolerateJustAfter: bool -> lineStr: string MaybeNull -> index: int -> (string * int * bool) option
+        tolerateJustAfter: bool -> lineStr: (string | null) -> index: int -> (string * int * bool) option
 
     /// Get the partial long name of the identifier to the left of index.
-    val GetPartialLongName: lineStr: string MaybeNull * index: int -> string list * string
+    val GetPartialLongName: lineStr: (string | null) * index: int -> string list * string
 
     /// Get the partial long name of the identifier to the left of index.
     /// For example, for `System.DateTime.Now` it returns PartialLongName ([|"System"; "DateTime"|], "Now", Some 32), where "32" pos of the last dot.
-    val GetPartialLongNameEx: lineStr: string MaybeNull * index: int -> PartialLongName
+    val GetPartialLongNameEx: lineStr: (string | null) * index: int -> PartialLongName
 
     /// Tests whether the user is typing something like "member x." or "override (*comment*) x."
     val TestMemberOrOverrideDeclaration: tokens: FSharpTokenInfo[] -> bool