Use ordinal string comparison in string manipulation methods

StartsWith, EndsWith, Compare, etc

fcs/FSharp.Compiler.Service.ProjectCrackerTool/Program.fs

@@ -10,8 +10,8 @@ module Program =
     let addMSBuildv14BackupResolution () =
         let onResolveEvent = new ResolveEventHandler(fun sender evArgs ->
             let requestedAssembly = AssemblyName(evArgs.Name)
-            if requestedAssembly.Name.StartsWith("Microsoft.Build") &&
-                not (requestedAssembly.Name.EndsWith(".resources")) && 
+            if requestedAssembly.Name.StartsWith("Microsoft.Build", StringComparison.Ordinal) &&
+                not (requestedAssembly.Name.EndsWith(".resources", StringComparison.Ordinal)) && 
                 not (requestedAssembly.Version.ToString().Contains("12.0.0.0")) 
             then
                 // If the version of MSBuild that we're using wasn't present on the machine, then 

src/absil/il.fs

@@ -362,14 +362,13 @@ let compareVersions x y =
         else 0
 
 let isMscorlib data =
-    if System.String.Compare(data.assemRefName, "mscorlib") = 0 then true 
-    else false
+    data.assemRefName = "mscorlib"
 
 let GetReferenceUnifiedVersion data = 
     let mutable highest = data.assemRefVersion
     if not (isMscorlib data) then 
         for ref in AssemblyRefUniqueStampGenerator.Table do
-            if System.String.Compare(ref.assemRefName, data.assemRefName) = 0 && highest < ref.assemRefVersion then 
+            if ref.assemRefName = data.assemRefName && highest < ref.assemRefVersion then 
                 highest <- ref.assemRefVersion
     highest
 

src/absil/illib.fs

@@ -538,7 +538,7 @@ module String =
     let (|StartsWith|_|) pattern value =
         if String.IsNullOrWhiteSpace value then
             None
-        elif value.StartsWith pattern then
+        elif value.StartsWith(pattern, StringComparison.Ordinal) then
             Some()
         else None
 
@@ -556,7 +556,7 @@ module String =
         while not (isNull !line) do
             yield !line
             line := reader.ReadLine()
-        if str.EndsWith("\n") then
+        if str.EndsWith("\n", StringComparison.Ordinal) then
             // last trailing space not returned
             // http://stackoverflow.com/questions/19365404/stringreader-omits-trailing-linebreak
             yield String.Empty

src/fsharp/CompileOps.fs

@@ -695,7 +695,7 @@ let OutputPhasedErrorR (os:StringBuilder) (err:PhasedDiagnostic) =
           | ContextInfo.TupleInRecordFields ->
                 os.Append(ErrorFromAddingTypeEquation1E().Format t2 t1 tpcs) |> ignore
                 os.Append(System.Environment.NewLine + FSComp.SR.commaInsteadOfSemicolonInRecord()) |> ignore
-          | _ when t2 = "bool" && t1.EndsWith " ref" ->
+          | _ when t2 = "bool" && t1.EndsWith(" ref", StringComparison.Ordinal) ->
                 os.Append(ErrorFromAddingTypeEquation1E().Format t2 t1 tpcs) |> ignore
                 os.Append(System.Environment.NewLine + FSComp.SR.derefInsteadOfNot()) |> ignore
           | _ -> os.Append(ErrorFromAddingTypeEquation1E().Format t2 t1 tpcs) |> ignore
@@ -1603,7 +1603,7 @@ let SanitizeFileName fileName implicitIncludeDir =
         let currentDir = implicitIncludeDir
 
         // if the file name is not rooted in the current directory, return the full path
-        if not(fullPath.StartsWith(currentDir)) then
+        if not(fullPath.StartsWith(currentDir, StringComparison.Ordinal)) then
             fullPath
         // if the file name is rooted in the current directory, return the relative path
         else
@@ -1795,7 +1795,7 @@ type private TypeInThisAssembly = class end
 let GetDefaultSystemValueTupleReference () =
     try
         let asm = typeof<System.ValueTuple<int, int>>.Assembly 
-        if asm.FullName.StartsWith "System.ValueTuple" then  
+        if asm.FullName.StartsWith("System.ValueTuple", StringComparison.Ordinal) then  
             Some asm.Location
         else
             let location = Path.GetDirectoryName(typeof<TypeInThisAssembly>.Assembly.Location)
@@ -3752,28 +3752,29 @@ type TcAssemblyResolutions(tcConfig: TcConfig, results: AssemblyResolution list,
 //--------------------------------------------------------------------------
 
 let IsSignatureDataResource         (r: ILResource) = 
-    r.Name.StartsWith FSharpSignatureDataResourceName ||
-    r.Name.StartsWith FSharpSignatureDataResourceName2
+    r.Name.StartsWith(FSharpSignatureDataResourceName, StringComparison.Ordinal) ||
+    r.Name.StartsWith(FSharpSignatureDataResourceName2, StringComparison.Ordinal)
 
 let IsOptimizationDataResource      (r: ILResource) = 
-    r.Name.StartsWith FSharpOptimizationDataResourceName || 
-    r.Name.StartsWith FSharpOptimizationDataResourceName2
+    r.Name.StartsWith(FSharpOptimizationDataResourceName, StringComparison.Ordinal)|| 
+    r.Name.StartsWith(FSharpOptimizationDataResourceName2, StringComparison.Ordinal)
 
 let GetSignatureDataResourceName    (r: ILResource) = 
-    if r.Name.StartsWith FSharpSignatureDataResourceName then 
+    if r.Name.StartsWith(FSharpSignatureDataResourceName, StringComparison.Ordinal) then 
         String.dropPrefix r.Name FSharpSignatureDataResourceName
-    elif r.Name.StartsWith FSharpSignatureDataResourceName2 then 
+    elif r.Name.StartsWith(FSharpSignatureDataResourceName2, StringComparison.Ordinal) then 
         String.dropPrefix r.Name FSharpSignatureDataResourceName2
     else failwith "GetSignatureDataResourceName"
 
 let GetOptimizationDataResourceName (r: ILResource) = 
-    if r.Name.StartsWith FSharpOptimizationDataResourceName then 
+    if r.Name.StartsWith(FSharpOptimizationDataResourceName, StringComparison.Ordinal) then 
         String.dropPrefix r.Name FSharpOptimizationDataResourceName
-    elif r.Name.StartsWith FSharpOptimizationDataResourceName2 then 
+    elif r.Name.StartsWith(FSharpOptimizationDataResourceName2, StringComparison.Ordinal) then 
         String.dropPrefix r.Name FSharpOptimizationDataResourceName2
     else failwith "GetOptimizationDataResourceName"
 
-let IsReflectedDefinitionsResource  (r: ILResource) = r.Name.StartsWith QuotationPickler.SerializedReflectedDefinitionsResourceNameBase
+let IsReflectedDefinitionsResource (r: ILResource) =
+    r.Name.StartsWith(QuotationPickler.SerializedReflectedDefinitionsResourceNameBase, StringComparison.Ordinal)
 
 let MakeILResource rname bytes = 
     { Name = rname

src/fsharp/CompileOptions.fs

@@ -188,7 +188,7 @@ module ResponseFile =
         let parseLine (l: string) =
             match l with
             | s when String.IsNullOrWhiteSpace(s) -> None
-            | s when l.StartsWith("#") -> Some (ResponseFileLine.Comment (s.TrimStart('#')))
+            | s when l.StartsWith("#", StringComparison.Ordinal) -> Some (ResponseFileLine.Comment (s.TrimStart('#')))
             | s -> Some (ResponseFileLine.CompilerOptionSpec (s.Trim()))
 
         try
@@ -224,7 +224,7 @@ let ParseCompilerOptions (collectOtherArgument : string -> unit, blocks: Compile
       if opt.Length = 2 || isSlashOpt opt then
         opt <- opt.[1 ..]
       // else, it should be a non-abbreviated option starting with "--"
-      elif opt.Length > 3 && opt.StartsWith("--") then
+      elif opt.Length > 3 && opt.StartsWith("--", StringComparison.Ordinal) then
         opt <- opt.[2 ..]
       else
         opt <- ""
@@ -259,7 +259,7 @@ let ParseCompilerOptions (collectOtherArgument : string -> unit, blocks: Compile
   let rec processArg args =    
     match args with 
     | [] -> ()
-    | ((rsp: string) :: t) when rsp.StartsWith("@") ->
+    | ((rsp: string) :: t) when rsp.StartsWith("@", StringComparison.Ordinal) ->
         let responseFileOptions =
             let fullpath =
                 try

src/fsharp/ConstraintSolver.fs

@@ -32,8 +32,8 @@
 
 module internal Microsoft.FSharp.Compiler.ConstraintSolver
 
+open System
 open Internal.Utilities.Collections
-
 open Microsoft.FSharp.Compiler 
 open Microsoft.FSharp.Compiler.AbstractIL 
 open Microsoft.FSharp.Compiler.AbstractIL.Internal.Library
@@ -1216,8 +1216,8 @@ and SolveMemberConstraint (csenv:ConstraintSolverEnv) ignoreUnresolvedOverload p
 
           // First look for a solution by a record property
           let recdPropSearch = 
-              let isGetProp = nm.StartsWith "get_" 
-              let isSetProp = nm.StartsWith "set_" 
+              let isGetProp = nm.StartsWith("get_", StringComparison.Ordinal) 
+              let isSetProp = nm.StartsWith("set_", StringComparison.Ordinal) 
               if argtys.IsEmpty && isGetProp || isSetProp then 
                   let propName = nm.[4..]
                   let props = 

src/fsharp/ErrorResolutionHints.fs

@@ -4,6 +4,7 @@
 module internal Microsoft.FSharp.Compiler.ErrorResolutionHints
 
 open Internal.Utilities
+open System
 
 let maxSuggestions = 5
 let minThresholdForSuggestions = 0.7
@@ -28,17 +29,18 @@ let FilterPredictions (idText:string) (suggestionF:ErrorLogger.Suggestions) =
     let allSuggestions = suggestionF()
 
     let demangle (nm:string) =
-        if nm.StartsWith "( " && nm.EndsWith " )" then
+        if nm.StartsWith("( ", StringComparison.Ordinal) && nm.EndsWith(" )", StringComparison.Ordinal) then
             let cleanName = nm.[2..nm.Length - 3]
             cleanName
         else nm
 
     /// Returns `true` if given string is an operator display name, e.g. ( |>> )
     let IsOperatorName (name: string) =
-        if not (name.StartsWith "( " && name.EndsWith " )") then false else
-        let name =  name.[2..name.Length - 3]
-        let res = name |> Seq.forall (fun c -> c <> ' ')
-        res        
+        if not (name.StartsWith("( ", StringComparison.Ordinal) && name.EndsWith(" )", StringComparison.Ordinal)) then
+            false
+        else
+            let name = name.[2..name.Length - 3]
+            name |> Seq.forall (fun c -> c <> ' ')
 
     if allSuggestions.Contains idText then [] else // some other parsing error occurred
     allSuggestions
@@ -47,11 +49,11 @@ let FilterPredictions (idText:string) (suggestionF:ErrorLogger.Suggestions) =
         // value as well as to formally squelch the associated compiler
         // error/warning (FS1182), we remove such names from the suggestions,
         // both to prevent accidental usages as well as to encourage good taste
-        if IsOperatorName suggestion || suggestion.StartsWith "_" then None else
+        if IsOperatorName suggestion || suggestion.StartsWith("_", StringComparison.Ordinal) then None else
         let suggestion:string = demangle suggestion
         let suggestedText = suggestion.ToUpperInvariant()
         let similarity = EditDistance.JaroWinklerDistance uppercaseText suggestedText
-        if similarity >= highConfidenceThreshold || suggestion.EndsWith ("." + idText) then
+        if similarity >= highConfidenceThreshold || suggestion.EndsWith("." + idText, StringComparison.Ordinal) then
             Some(similarity, suggestion)
         elif similarity < minThresholdForSuggestions && suggestedText.Length > minStringLengthForThreshold then
             None

src/fsharp/MethodCalls.fs

@@ -3,6 +3,7 @@
 /// Logic associated with resolving method calls.
 module internal Microsoft.FSharp.Compiler.MethodCalls
 
+open System
 open Microsoft.FSharp.Compiler 
 open Microsoft.FSharp.Compiler.AbstractIL.IL 
 open Microsoft.FSharp.Compiler.AbstractIL.Internal.Library 
@@ -23,6 +24,7 @@ open Microsoft.FSharp.Compiler.AttributeChecking
 
 #if !NO_EXTENSIONTYPING
 open Microsoft.FSharp.Compiler.ExtensionTyping
+
 #endif
 
 
@@ -1260,7 +1262,9 @@ let MethInfoChecks g amap isInstance tyargsOpt objArgs ad m (minfo:MethInfo)  =
     if not (IsTypeAndMethInfoAccessible amap m adOriginal ad minfo) then 
       error (Error (FSComp.SR.tcMethodNotAccessible(minfo.LogicalName), m))
 
-    if isAnyTupleTy g minfo.ApparentEnclosingType && not minfo.IsExtensionMember && (minfo.LogicalName.StartsWith "get_Item" || minfo.LogicalName.StartsWith "get_Rest") then
+    if isAnyTupleTy g minfo.ApparentEnclosingType && not minfo.IsExtensionMember &&
+        (minfo.LogicalName.StartsWith("get_Item", StringComparison.Ordinal) ||
+         minfo.LogicalName.StartsWith("get_Rest", StringComparison.Ordinal)) then
       warning (Error (FSComp.SR.tcTupleMemberNotNormallyUsed(), m))
 
     CheckMethInfoAttributes g m tyargsOpt minfo |> CommitOperationResult

src/fsharp/NameResolution.fs

@@ -4,6 +4,7 @@
 /// Name environment and name resolution 
 module internal Microsoft.FSharp.Compiler.NameResolution
 
+open System
 open Internal.Utilities
 open Microsoft.FSharp.Compiler 
 open Microsoft.FSharp.Compiler.Range
@@ -2872,7 +2873,7 @@ let rec ResolveTypeLongIdentPrim sink (ncenv:NameResolver) occurence first fully
                             | ItemOccurence.UseInAttribute -> 
                                 [yield e.Value.DisplayName
                                  yield e.Value.DemangledModuleOrNamespaceName
-                                 if e.Value.DisplayName.EndsWith "Attribute" then
+                                 if e.Value.DisplayName.EndsWith("Attribute", StringComparison.Ordinal) then
                                      yield e.Value.DisplayName.Replace("Attribute","")]
                             | _ -> [e.Value.DisplayName; e.Value.DemangledModuleOrNamespaceName])
                         |> HashSet
@@ -3580,7 +3581,7 @@ let ResolveCompletionsInType (ncenv: NameResolver) nenv (completionTargets: Reso
                 if methsWithStaticParams.IsEmpty then minfos
                 else minfos |> List.filter (fun minfo -> 
                         let nm = minfo.LogicalName
-                        not (nm.Contains "," && methsWithStaticParams |> List.exists (fun m -> nm.StartsWith(m))))
+                        not (nm.Contains "," && methsWithStaticParams |> List.exists (fun m -> nm.StartsWith(m, StringComparison.Ordinal))))
 #endif
 
             minfos 
@@ -4209,7 +4210,7 @@ let ResolveCompletionsInTypeForItem (ncenv: NameResolver) nenv m ad statics typ
                         if methsWithStaticParams.IsEmpty then minfos
                         else minfos |> List.filter (fun minfo -> 
                                 let nm = minfo.LogicalName
-                                not (nm.Contains "," && methsWithStaticParams |> List.exists (fun m -> nm.StartsWith(m))))
+                                not (nm.Contains "," && methsWithStaticParams |> List.exists (fun m -> nm.StartsWith(m, StringComparison.Ordinal))))
         #endif
 
                     minfos 

src/fsharp/NicePrint.fs

@@ -6,6 +6,7 @@
 
 module internal Microsoft.FSharp.Compiler.NicePrint
 
+open System
 open Microsoft.FSharp.Compiler.AbstractIL 
 open Microsoft.FSharp.Compiler.AbstractIL.IL 
 open Microsoft.FSharp.Compiler.AbstractIL.Internal 
@@ -71,7 +72,7 @@ module internal PrintUtilities =
                     tcref.DisplayName // has no static params
                 else
                     tcref.DisplayName+"<...>" // shorten
-            if isAttribute && name.EndsWith "Attribute" then
+            if isAttribute && name.EndsWith("Attribute", StringComparison.Ordinal) then
                 String.dropSuffix name "Attribute"
             else 
                 name
@@ -655,7 +656,7 @@ module private PrintTypes =
         | ILAttrib ilMethRef -> 
             let trimmedName = 
                 let name = ilMethRef.DeclaringTypeRef.Name
-                if name.EndsWith "Attribute" then
+                if name.EndsWith("Attribute", StringComparison.Ordinal) then
                     String.dropSuffix name "Attribute"
                 else
                     name

src/fsharp/PostInferenceChecks.fs

@@ -23,6 +23,7 @@ open Microsoft.FSharp.Compiler.Infos
 open Microsoft.FSharp.Compiler.PrettyNaming
 open Microsoft.FSharp.Compiler.InfoReader
 open Microsoft.FSharp.Compiler.TypeRelations
+open System
 
 //--------------------------------------------------------------------------
 // TestHooks - for dumping range to support source transforms
@@ -1309,14 +1310,14 @@ let CheckModuleBinding cenv env (TBind(v,e,_) as bind) =
 
                 // Default augmentation contains the nasty 'Case<UnionCase>' etc.
                 let prefix = "New"
-                if nm.StartsWith prefix then
+                if nm.StartsWith(prefix, StringComparison.Ordinal) then
                     match tcref.GetUnionCaseByName(nm.[prefix.Length ..]) with 
                     | Some(uc) -> error(NameClash(nm,kind,v.DisplayName,v.Range, FSComp.SR.chkUnionCaseCompiledForm(),uc.DisplayName,uc.Range))
                     | None -> ()
 
                 // Default augmentation contains the nasty 'Is<UnionCase>' etc.
                 let prefix = "Is"
-                if nm.StartsWith prefix && hasDefaultAugmentation then
+                if nm.StartsWith(prefix, StringComparison.Ordinal) && hasDefaultAugmentation then
                     match tcref.GetUnionCaseByName(nm.[prefix.Length ..]) with 
                     | Some(uc) -> error(NameClash(nm,kind,v.DisplayName,v.Range, FSComp.SR.chkUnionCaseDefaultAugmentation(),uc.DisplayName,uc.Range))
                     | None -> ()

src/fsharp/PrettyNaming.fs

@@ -18,6 +18,7 @@ module public Microsoft.FSharp.Compiler.PrettyNaming
     open Internal.Utilities
     open Internal.Utilities.StructuredFormat
     open Internal.Utilities.StructuredFormat.LayoutOps
+    open System
 
 #if FX_RESHAPED_REFLECTION
     open Microsoft.FSharp.Core.ReflectionAdapters
@@ -136,13 +137,15 @@ module public Microsoft.FSharp.Compiler.PrettyNaming
 
     /// Returns `true` if given string is an operator display name, e.g. ( |>> )
     let IsOperatorName (name: string) =
-        let name = if name.StartsWith "( " && name.EndsWith " )" then name.[2..name.Length - 3] else name
+        let name =
+            if name.StartsWith("( ", StringComparison.Ordinal) && name.EndsWith(" )", StringComparison.Ordinal) then
+                name.[2 .. name.Length - 3]
+            else name
         // there is single operator containing a space - range operator with step: `.. ..`
-        let res = name = ".. .." || name |> Seq.forall (fun c -> opCharSet.Contains c && c <> ' ')
-        res
+        name = ".. .." || name |> Seq.forall (fun c -> opCharSet.Contains c && c <> ' ')
 
     let IsMangledOpName (n:string) =
-        n.StartsWith (opNamePrefix, StringComparison.Ordinal)
+        n.StartsWith(opNamePrefix, StringComparison.Ordinal)
 
     /// Compiles a custom operator into a mangled operator name.
     /// For example, "!%" becomes "op_DereferencePercent".
@@ -468,7 +471,7 @@ module public Microsoft.FSharp.Compiler.PrettyNaming
         if IsCompilerGeneratedName nm then nm else nm+compilerGeneratedMarker
 
     let GetBasicNameOfPossibleCompilerGeneratedName (name:string) =
-            match name.IndexOf compilerGeneratedMarker with 
+            match name.IndexOf(compilerGeneratedMarker, StringComparison.Ordinal) with 
             | -1 | 0 -> name
             | n -> name.[0..n-1]
 

src/fsharp/QuotationTranslator.fs

@@ -15,6 +15,7 @@ open Microsoft.FSharp.Compiler.PrettyNaming
 open Microsoft.FSharp.Compiler.ErrorLogger
 open Microsoft.FSharp.Compiler.TcGlobals
 open Microsoft.FSharp.Compiler.Range
+open System
 open System.Collections.Generic
 
 module QP = Microsoft.FSharp.Compiler.QuotationPickler
@@ -161,7 +162,7 @@ let (|ObjectInitializationCheck|_|) g expr =
            [| TTarget([], Expr.App(Expr.Val(failInitRef, _, _), _, _, _, _), _); _ |], _, resultTy
         ) when 
             IsCompilerGeneratedName name &&
-            name.StartsWith "init" &&
+            name.StartsWith("init", StringComparison.Ordinal) &&
             selfRef.BaseOrThisInfo = MemberThisVal &&
             valRefEq g failInitRef (ValRefForIntrinsic g.fail_init_info) &&
             isUnitTy g resultTy -> Some()

src/fsharp/SimulatedMSBuildReferenceResolver.fs

@@ -103,7 +103,7 @@ let internal SimulatedMSBuildResolver =
 #if !FX_RESHAPED_MSBUILD
                 // For this one we need to get the version search exactly right, without doing a load
                 try 
-                    if not found && r.StartsWith("FSharp.Core, Version=")  && Environment.OSVersion.Platform = PlatformID.Win32NT then 
+                    if not found && r.StartsWith("FSharp.Core, Version=", StringComparison.Ordinal) && Environment.OSVersion.Platform = PlatformID.Win32NT then 
                         let n = AssemblyName(r)
                         let fscoreDir0 = 
                             let PF =