dotnet · KevinRansom · Aug 23, 2016 · Aug 23, 2016 · Aug 23, 2016 · Aug 23, 2016
diff --git a/src/absil/illib.fs b/src/absil/illib.fs
@@ -716,8 +716,8 @@ type LazyWithContext<'T,'ctxt> =
           funcOrException = box f;
           findOriginalException = findOriginalException }
     static member NotLazy(x:'T) : LazyWithContext<'T,'ctxt> = 
-        { value = x;
-          funcOrException = null;
+        { value = x
+          funcOrException = null
           findOriginalException = id }
     member x.IsDelayed = (match x.funcOrException with null -> false | :? LazyWithContextFailure -> false | _ -> true)
     member x.IsForced = (match x.funcOrException with null -> true | _ -> false)

diff --git a/src/absil/ilwritepdb.fs b/src/absil/ilwritepdb.fs
@@ -205,10 +205,9 @@ let writePortablePdbInfo (fixupSPs:bool) showTimes fpdb (info:PdbData) =
     let _spCounts, _allSps = fixupOverlappingSequencePoints fixupSPs showTimes info.Methods
     let externalRowCounts = getRowCounts info.TableRowCounts
     let docs = 
-        if info.Documents = null then 
-            Array.empty<PdbDocumentData>
-        else
-            info.Documents
+        match info.Documents with
+        | null -> Array.empty<PdbDocumentData>
+        | _ -> info.Documents
 
     let metadata = MetadataBuilder()
     let serializeDocumentName (name:string) =
@@ -251,9 +250,9 @@ let writePortablePdbInfo (fixupSPs:bool) showTimes fpdb (info:PdbData) =
     info.Methods |> Array.iteri (fun _i minfo ->
         let docHandle, sequencePointBlob =
             let sps =
-                if minfo.SequencePoints = null then
-                    Array.empty<PdbSequencePoint>
-                else 
+                match minfo.SequencePoints with
+                | null -> Array.empty<PdbSequencePoint>
+                | _ ->
                     match minfo.Range with
                     | None -> Array.empty<PdbSequencePoint>
                     | Some (_,_) -> minfo.SequencePoints
@@ -266,7 +265,7 @@ let writePortablePdbInfo (fixupSPs:bool) showTimes fpdb (info:PdbData) =
                     | false, _ -> Unchecked.defaultof<DocumentHandle>
                     | true, f  -> f
 
-            // Return a document that the entire method body is declared within. 
+            // Return a document that the entire method body is declared within.
             // If part of the method body is in another document returns nil handle.
             let tryGetSingleDocumentIndex =
                 let mutable singleDocumentIndex = 0

diff --git a/src/fsharp/ErrorLogger.fs b/src/fsharp/ErrorLogger.fs
@@ -518,7 +518,7 @@ let NewlineifyErrorString (message:string) = message.Replace(stringThatIsAProxyF
 /// NOTE: newlines are recognized and replaced with stringThatIsAProxyForANewlineInFlatErrors (ASCII 29, the 'group separator'), 
 /// which is decoded by the IDE with 'NewlineifyErrorString' back into newlines, so that multi-line errors can be displayed in QuickInfo
 let NormalizeErrorString (text : string) =    
-    if text = null then nullArg "text"
+    if isNull text then nullArg "text"
     let text = text.Trim()
 
     let buf = System.Text.StringBuilder()

diff --git a/src/fsharp/FSharp.Core/control.fs b/src/fsharp/FSharp.Core/control.fs
@@ -50,7 +50,7 @@ namespace System.Threading
 
             member this.Equals(ctr:CancellationTokenRegistration) =
                 match this.source with
-                |   null -> ctr.source = null
+                |   null -> isNull ctr.source
                 |   _ ->  this.source.Equals(ctr.source) && this.id = ctr.id
 
             override this.Equals(o:obj) =
@@ -91,7 +91,7 @@ namespace System.Threading
 
             member this.Equals(ct:CancellationToken) =
                 match this.source with
-                |   null -> ct.source = null
+                |   null -> isNull ct.source
                 |   _ -> this.source.Equals(ct.source)
 
             override this.Equals(o:obj) =

diff --git a/src/fsharp/FSharp.Core/math/z.fs b/src/fsharp/FSharp.Core/math/z.fs
@@ -305,7 +305,7 @@ namespace System.Numerics
             | _ -> invalidArg "x" "signs should be +/- 1 or 0"
 
         static member Parse(text:string) =
-            if text = null then raise (new ArgumentNullException("text"))
+            if isNull text then raise (new ArgumentNullException("text"))
             let text = text.Trim()
             let len = text.Length 
             if len = 0 then raise (new System.FormatException(SR.GetString(SR.badFormatString)))

diff --git a/src/fsharp/FSharp.Core/prim-types.fs b/src/fsharp/FSharp.Core/prim-types.fs
@@ -4128,7 +4128,7 @@ namespace Microsoft.FSharp.Core
 #if FX_NO_CHAR_PARSE
         // replace System.Char.Parse
         let inline charParse (s: string) =
-            if s = null then raise (System.ArgumentNullException())
+            if isNull s then raise (System.ArgumentNullException())
             elif s.Length = 1 then s.[0]
             else raise (System.FormatException "String must be exactly one character long.")
 #endif

diff --git a/src/fsharp/FSharp.Core/printf.fs b/src/fsharp/FSharp.Core/printf.fs
@@ -490,7 +490,10 @@ module internal PrintfImpl =
     let invariantCulture = System.Globalization.CultureInfo.InvariantCulture 
 
     let inline boolToString v = if v then "true" else "false"
-    let inline stringToSafeString v = if v = null then "" else v
+    let inline stringToSafeString v = 
+        match v with
+        | null -> ""
+        | _ -> v
 
     [<Literal>]
     let DefaultPrecision = 6
@@ -1001,25 +1004,30 @@ module internal PrintfImpl =
     type private PrintfBuilder<'S, 'Re, 'Res>() =
 
         let mutable count = 0
-
-        let verifyMethodInfoWasTaken (_mi : System.Reflection.MemberInfo) =
 #if DEBUG
-            if _mi = null then 
+        let verifyMethodInfoWasTaken (mi : System.Reflection.MemberInfo) =
+            if isNull mi then 
                 ignore (System.Diagnostics.Debugger.Launch())
 #else
-            ()
 #endif
 
         let buildSpecialChained(spec : FormatSpecifier, argTys : Type[], prefix : string, tail : obj, retTy) = 
             if spec.TypeChar = 'a' then
                 let mi = typeof<Specializations<'S, 'Re, 'Res>>.GetMethod("LittleAChained", NonPublicStatics)
+#if DEBUG
                 verifyMethodInfoWasTaken mi
+#else
+#endif
+
                 let mi = mi.MakeGenericMethod([| argTys.[1];  retTy |])
                 let args = [| box prefix; tail   |]
                 mi.Invoke(null, args)
             elif spec.TypeChar = 't' then
                 let mi = typeof<Specializations<'S, 'Re, 'Res>>.GetMethod("TChained", NonPublicStatics)
+#if DEBUG
                 verifyMethodInfoWasTaken mi
+#else
+#endif
                 let mi = mi.MakeGenericMethod([| retTy |])
                 let args = [| box prefix; tail |]
                 mi.Invoke(null, args)
@@ -1031,9 +1039,10 @@ module internal PrintfImpl =
                     let prefix = if spec.TypeChar = '%' then "PercentStarChained" else "StarChained"
                     let name = prefix + (string n)
                     typeof<Specializations<'S, 'Re, 'Res>>.GetMethod(name, NonPublicStatics)
-
+#if DEBUG                
                 verifyMethodInfoWasTaken mi
-
+#else
+#endif                
                 let argTypes, args =
                     if spec.TypeChar = '%' then
                         [| retTy |], [| box prefix; tail |]
@@ -1048,13 +1057,19 @@ module internal PrintfImpl =
         let buildSpecialFinal(spec : FormatSpecifier, argTys : Type[], prefix : string, suffix : string) =
             if spec.TypeChar = 'a' then
                 let mi = typeof<Specializations<'S, 'Re, 'Res>>.GetMethod("LittleAFinal", NonPublicStatics)
+#if DEBUG
                 verifyMethodInfoWasTaken mi
+#else
+#endif
                 let mi = mi.MakeGenericMethod(argTys.[1] : Type)
                 let args = [| box prefix; box suffix |]
                 mi.Invoke(null, args)
             elif spec.TypeChar = 't' then
                 let mi = typeof<Specializations<'S, 'Re, 'Res>>.GetMethod("TFinal", NonPublicStatics)
+#if DEBUG
                 verifyMethodInfoWasTaken mi
+#else
+#endif
                 let args = [| box prefix; box suffix |]
                 mi.Invoke(null, args)
             else
@@ -1065,8 +1080,10 @@ module internal PrintfImpl =
                     let prefix = if spec.TypeChar = '%' then "PercentStarFinal" else "StarFinal"
                     let name = prefix + (string n)
                     typeof<Specializations<'S, 'Re, 'Res>>.GetMethod(name, NonPublicStatics)
-               
+#if DEBUG
                 verifyMethodInfoWasTaken mi
+#else
+#endif
 
                 let mi, args = 
                     if spec.TypeChar = '%' then 
@@ -1081,13 +1098,19 @@ module internal PrintfImpl =
 
         let buildPlainFinal(args : obj[], argTypes : Type[]) = 
             let mi = typeof<Specializations<'S, 'Re, 'Res>>.GetMethod("Final" + (argTypes.Length.ToString()), NonPublicStatics)
+#if DEBUG
             verifyMethodInfoWasTaken mi
+#else
+#endif
             let mi = mi.MakeGenericMethod(argTypes)
             mi.Invoke(null, args)
 
         let buildPlainChained(args : obj[], argTypes : Type[]) = 
             let mi = typeof<Specializations<'S, 'Re, 'Res>>.GetMethod("Chained" + ((argTypes.Length - 1).ToString()), NonPublicStatics)
+#if DEBUG
             verifyMethodInfoWasTaken mi
+#else
+#endif
             let mi = mi.MakeGenericMethod(argTypes)
             mi.Invoke(null, args)   
 

diff --git a/src/fsharp/FSharp.Core/quotations.fs b/src/fsharp/FSharp.Core/quotations.fs
@@ -931,7 +931,7 @@ module Patterns =
             | Some methInfo -> methInfo 
 
     let bindMethodHelper (parentT: Type, nm,marity,argtys,rty) =
-      if parentT = null then invalidArg "parentT" (SR.GetString(SR.QparentCannotBeNull))
+      if isNull parentT then invalidArg "parentT" (SR.GetString(SR.QparentCannotBeNull))
       if marity = 0 then 
           let tyargTs = if parentT.IsGenericType then parentT.GetGenericArguments() else [| |] 
           let argTs = Array.ofList (List.map (instFormal tyargTs) argtys) 

diff --git a/src/fsharp/TypeChecker.fs b/src/fsharp/TypeChecker.fs
@@ -5162,7 +5162,7 @@ and TcPat warnOnUpper cenv env topValInfo vFlags (tpenv,names,takenNames) ty pat
                             | _ ->
                                 error(Error(FSComp.SR.tcUnionCaseFieldCannotBeUsedMoreThanOnce(id.idText), id.idRange))
                     for i = 0 to nargtys - 1 do
-                        if box result.[i] = null then
+                        if isNull (box result.[i]) then
                             result.[i] <- SynPat.Wild(m.MakeSynthetic())
 
                     let args = List.ofArray result
@@ -8299,7 +8299,7 @@ and TcItemThen cenv overallTy env tpenv (item,mItem,rest,afterOverloadResolution
                     for (_, id, arg) in namedCallerArgs do
                         match argNames |> List.tryFindIndex (fun id2 -> id.idText = id2.idText) with
                         | Some i -> 
-                            if box fittedArgs.[i] = null then
+                            if isNull(box fittedArgs.[i]) then
                                 fittedArgs.[i] <- arg
                                 let argContainerOpt = match item with
                                                       | Item.UnionCase(uci,_) -> Some(ArgumentContainer.UnionCase(uci))
@@ -8325,7 +8325,7 @@ and TcItemThen cenv overallTy env tpenv (item,mItem,rest,afterOverloadResolution
                                 | _ -> false
 
                             if isSpecialCaseForBackwardCompatibility then
-                                assert (box fittedArgs.[currentIndex] = null)
+                                assert (isNull(box fittedArgs.[currentIndex]))
                                 fittedArgs.[currentIndex] <- List.item currentIndex args // grab original argument, not item from the list of named parametere
                                 currentIndex <- currentIndex + 1
                             else

diff --git a/src/fsharp/infos.fs b/src/fsharp/infos.fs
@@ -561,24 +561,26 @@ type ParamData =
 type ILFieldInit with 
     /// Compute the ILFieldInit for the given provided constant value for a provided enum type.
     static member FromProvidedObj m (v:obj) = 
-        if v = null then ILFieldInit.Null else
-        let objTy = v.GetType()
-        let v = if objTy.IsEnum then objTy.GetField("value__").GetValue(v) else v
-        match v with 
-        | :? single as i -> ILFieldInit.Single i
-        | :? double as i -> ILFieldInit.Double i
-        | :? bool as i -> ILFieldInit.Bool i
-        | :? char as i -> ILFieldInit.Char (uint16 i)
-        | :? string as i -> ILFieldInit.String i
-        | :? sbyte as i -> ILFieldInit.Int8 i
-        | :? byte as i -> ILFieldInit.UInt8 i
-        | :? int16 as i -> ILFieldInit.Int16 i
-        | :? uint16 as i -> ILFieldInit.UInt16 i
-        | :? int as i -> ILFieldInit.Int32 i
-        | :? uint32 as i -> ILFieldInit.UInt32 i
-        | :? int64 as i -> ILFieldInit.Int64 i
-        | :? uint64 as i -> ILFieldInit.UInt64 i
-        | _ -> error(Error(FSComp.SR.infosInvalidProvidedLiteralValue(try v.ToString() with _ -> "?"),m))
+        match v with
+        | null -> ILFieldInit.Null
+        | _ ->
+            let objTy = v.GetType()
+            let v = if objTy.IsEnum then objTy.GetField("value__").GetValue(v) else v
+            match v with 
+            | :? single as i -> ILFieldInit.Single i
+            | :? double as i -> ILFieldInit.Double i
+            | :? bool as i -> ILFieldInit.Bool i
+            | :? char as i -> ILFieldInit.Char (uint16 i)
+            | :? string as i -> ILFieldInit.String i
+            | :? sbyte as i -> ILFieldInit.Int8 i
+            | :? byte as i -> ILFieldInit.UInt8 i
+            | :? int16 as i -> ILFieldInit.Int16 i
+            | :? uint16 as i -> ILFieldInit.UInt16 i
+            | :? int as i -> ILFieldInit.Int32 i
+            | :? uint32 as i -> ILFieldInit.UInt32 i
+            | :? int64 as i -> ILFieldInit.Int64 i
+            | :? uint64 as i -> ILFieldInit.UInt64 i
+            | _ -> error(Error(FSComp.SR.infosInvalidProvidedLiteralValue(try v.ToString() with _ -> "?"),m))
 
 
 /// Compute the OptionalArgInfo for a provided parameter. 

diff --git a/src/fsharp/vs/ServiceDeclarations.fs b/src/fsharp/vs/ServiceDeclarations.fs
@@ -1243,7 +1243,7 @@ type FSharpDeclarationListItem(name, glyph:int, info) =
 
                 // The dataTipSpinWaitTime limits how long we block the UI thread while a tooltip pops up next to a selected item in an IntelliSense completion list.
                 // This time appears to be somewhat amortized by the time it takes the VS completion UI to actually bring up the tooltip after selecting an item in the first place.
-                if task = null then
+                if isNull task then
                     // kick off the actual (non-cooperative) work
                     task <- System.Threading.Tasks.Task.Factory.StartNew(fun() -> 
                         let text = decl.DescriptionTextAsync |> Async.RunSynchronously

diff --git a/src/utils/CompilerLocationUtils.fs b/src/utils/CompilerLocationUtils.fs
@@ -99,12 +99,13 @@ module internal FSharpEnvironment =
         Option.ofString
             (try
                 let key = RegistryKey.OpenBaseKey(RegistryHive.LocalMachine, RegistryView.Registry32)
-                if key = null then null
-                else
+                match key with
+                | null -> null
+                | _ ->
                     let sub = key.OpenSubKey(subKey)
-                    if sub = null then null
-                    else 
-                        downcast (sub.GetValue(null, null))
+                    match sub with
+                    | null -> null
+                    | _ -> downcast (sub.GetValue(null, null))
              with e->
                 System.Diagnostics.Debug.Assert(false, sprintf "Failed in Get32BitRegistryStringValueViaDotNet: %s" (e.ToString()))
                 null)

diff --git a/src/utils/sformat.fs b/src/utils/sformat.fs
@@ -832,7 +832,7 @@ namespace Microsoft.FSharp.Text.StructuredFormat
                             | res -> 
                                let attr = (res.[0] :?> StructuredFormatDisplayAttribute) 
                                let txt = attr.Value
-                               if txt = null || txt.Length <= 1 then  
+                               if isNull txt || txt.Length <= 1 then  
                                    None
                                else
                                   let messageRegexPattern = @"^(?<pre>.*?)(?<!\\){(?<prop>.*?)(?<!\\)}(?<post>.*)$"
@@ -1169,8 +1169,11 @@ namespace Microsoft.FSharp.Text.StructuredFormat
             | :? unativeint  as d -> d.ToString() + "un"
             | :? bool   as b -> (if b then "true" else "false")
             | :? char   as c -> "\'" + formatChar true c + "\'"
-            | _ -> try  let text = obj.ToString()
-                        if text = null then "" else text
+            | _ -> try 
+                        let text = obj.ToString()
+                        match text with
+                        | null -> ""
+                        | _ -> text
                    with e ->
                      // If a .ToString() call throws an exception, catch it and use the message as the result.
                      // This may be informative, e.g. division by zero etc...

diff --git a/vsintegration/src/FSharp.LanguageService/BackgroundRequests.fs b/vsintegration/src/FSharp.LanguageService/BackgroundRequests.fs
@@ -256,7 +256,7 @@ type internal FSharpLanguageServiceBackgroundRequests
     // Called before a Goto Definition to wait a moment to synchonize the parse
     member fls.TrySynchronizeParseFileInformation(view: IVsTextView, source: ISource, millisecondsTimeout:int) =
 
-        if (lastParseFileRequest = null || lastParseFileRequest.Timestamp <> source.ChangeCount) then
+        if isNull lastParseFileRequest || lastParseFileRequest.Timestamp <> source.ChangeCount then
             let req = fls.TriggerParseFile(view, source)
 
             if req <> null && (req.IsSynchronous || req.Result <> null) then

diff --git a/vsintegration/src/FSharp.LanguageService/FSharpSource.fs b/vsintegration/src/FSharp.LanguageService/FSharpSource.fs
@@ -438,7 +438,7 @@ type internal FSharpSource(service:LanguageService, textLines, colorizer, vsFile
         member source.HandleCompletionResponse(req) =
             match req with
             | null -> source.ResetFSharpIntelliSenseToAppearAdornment()
-            | _ when req.View = null || req.ResultIntellisenseInfo = null -> source.ResetFSharpIntelliSenseToAppearAdornment()
+            | _ when isNull req.View || isNull req.ResultIntellisenseInfo -> source.ResetFSharpIntelliSenseToAppearAdornment()
             | _ when (req.Timestamp <> source.ChangeCount) -> source.ResetFSharpIntelliSenseToAppearAdornment()
             | _ ->
                   source.HandleResponseHelper(req)
@@ -448,7 +448,7 @@ type internal FSharpSource(service:LanguageService, textLines, colorizer, vsFile
                   async {
                       let! decls = req.ResultIntellisenseInfo.GetDeclarations(req.Snapshot, req.Line, req.Col, reason)
                       do! Async.SwitchToContext UIThread.TheSynchronizationContext
-                      if (decls = null || decls.IsEmpty()) && req.Timestamp <> req.ResultTimestamp then
+                      if (isNull decls || decls.IsEmpty()) && req.Timestamp <> req.ResultTimestamp then
                           // Second chance intellisense: we didn't get any result and the basis typecheck was stale. We need to retrigger the completion.
                           source.Completion(req.View, req.TokenInfo, req.Reason, RequireFreshResults.Yes)
                       else