Warnings for invalid #nowarn arguments

docs/release-notes/.FSharp.Compiler.Service/9.0.200.md

@@ -27,5 +27,6 @@
 * Better ranges for `inherit` error reporting. ([PR #17879](https://github.com/dotnet/fsharp/pull/17879))
 * Better ranges for `inherit` `struct` error reporting. ([PR #17886](https://github.com/dotnet/fsharp/pull/17886))
 * Better ranges for `inherit` objects error reporting. ([PR #17893](https://github.com/dotnet/fsharp/pull/17893))
+* Better ranges for #nowarn error reporting; bring back #nowarn warnings for --langVersion:80; add warnings under feature flag ([PR #17871](https://github.com/dotnet/fsharp/pull/17871))
 
 ### Breaking Changes

src/Compiler/Driver/CompilerConfig.fs

@@ -27,6 +27,7 @@ open FSharp.Compiler.Text.Range
 open FSharp.Compiler.Xml
 open FSharp.Compiler.TypedTree
 open FSharp.Compiler.BuildGraph
+open System.Text.RegularExpressions
 
 #if !NO_TYPEPROVIDERS
 open FSharp.Core.CompilerServices
@@ -91,24 +92,37 @@ let ResolveFileUsingPaths (paths, m, fileName) =
         let searchMessage = String.concat "\n " paths
         raise (FileNameNotResolved(fileName, searchMessage, m))
 
-let GetWarningNumber (m, warningNumber: string, prefixSupported) =
-    try
-        let warningNumber =
-            if warningNumber.StartsWithOrdinal "FS" then
-                if prefixSupported then
-                    warningNumber.Substring 2
-                else
-                    raise (new ArgumentException())
-            else
-                warningNumber
+let GetWarningNumber (m, numStr: string, langVersion: LanguageVersion, isCompilerOption: bool) =
+    let argFeature = LanguageFeature.ParsedHashDirectiveArgumentNonQuotes
+    let errorInvalid = Error(FSComp.SR.buildInvalidWarningNumber numStr, m)
+    let rxOptions = RegexOptions.CultureInvariant
+
+    let getNumber regexString failAction =
+        let mtch = Regex(regexString, rxOptions).Match(numStr)
 
-        if Char.IsDigit(warningNumber[0]) then
-            Some(int32 warningNumber)
+        if mtch.Success then
+            Some(int mtch.Groups[2].Captures[0].Value)
         else
+            failAction ()
             None
-    with _ ->
-        warning (Error(FSComp.SR.buildInvalidWarningNumber warningNumber, m))
+
+    let matches regexString =
+        Regex(regexString, rxOptions).Match(numStr).Success
+
+    if isCompilerOption then
+        getNumber """^(FS)?(\d+)$""" (fun () ->
+            if not (matches """^([A-Z]+)(\d+)$""") then
+                warning errorInvalid)
+    elif langVersion.SupportsFeature(argFeature) then
+        getNumber """^("?)(?:(?:FS)?(\d+))\1$""" (fun () -> warning errorInvalid)
+    elif matches """^[^"].+$""" then
+        errorR (languageFeatureError langVersion argFeature m)
+        None
+    elif matches """^"FS.*"$""" then
+        warning errorInvalid
         None
+    else
+        getNumber """^(")(\d+)"$""" (fun () -> ())
 
 let ComputeMakePathAbsolute implicitIncludeDir (path: string) =
     try
@@ -931,7 +945,7 @@ type TcConfigBuilder =
     member tcConfigB.TurnWarningOff(m, s: string) =
         use _ = UseBuildPhase BuildPhase.Parameter
 
-        match GetWarningNumber(m, s, tcConfigB.langVersion.SupportsFeature(LanguageFeature.ParsedHashDirectiveArgumentNonQuotes)) with
+        match GetWarningNumber(m, s, tcConfigB.langVersion, true) with
         | None -> ()
         | Some n ->
             // nowarn:62 turns on mlCompatibility, e.g. shows ML compat items in intellisense menus
@@ -946,7 +960,7 @@ type TcConfigBuilder =
     member tcConfigB.TurnWarningOn(m, s: string) =
         use _ = UseBuildPhase BuildPhase.Parameter
 
-        match GetWarningNumber(m, s, tcConfigB.langVersion.SupportsFeature(LanguageFeature.ParsedHashDirectiveArgumentNonQuotes)) with
+        match GetWarningNumber(m, s, tcConfigB.langVersion, true) with
         | None -> ()
         | Some n ->
             // warnon 62 turns on mlCompatibility, e.g. shows ML compat items in intellisense menus

src/Compiler/Driver/CompilerConfig.fsi

@@ -922,7 +922,7 @@ val TryResolveFileUsingPaths: paths: string seq * m: range * fileName: string ->
 
 val ResolveFileUsingPaths: paths: string seq * m: range * fileName: string -> string
 
-val GetWarningNumber: m: range * warningNumber: string * prefixSupported: bool -> int option
+val GetWarningNumber: m: range * numStr: string * langVersion: LanguageVersion * isCompilerOption: bool -> int option
 
 /// Get the name used for FSharp.Core
 val GetFSharpCoreLibraryName: unit -> string

src/Compiler/Driver/CompilerOptions.fs

@@ -832,15 +832,15 @@ let errorsAndWarningsFlags (tcConfigB: TcConfigBuilder) =
         CompilerOption(
             "nowarn",
             tagWarnList,
-            OptionStringList(fun n -> tcConfigB.TurnWarningOff(rangeCmdArgs, trimFS n)),
+            OptionStringList(fun n -> tcConfigB.TurnWarningOff(rangeCmdArgs, n)),
             None,
             Some(FSComp.SR.optsNowarn ())
         )
 
         CompilerOption(
             "warnon",
             tagWarnList,
-            OptionStringList(fun n -> tcConfigB.TurnWarningOn(rangeCmdArgs, trimFS n)),
+            OptionStringList(fun n -> tcConfigB.TurnWarningOn(rangeCmdArgs, n)),
             None,
             Some(FSComp.SR.optsWarnOn ())
         )

src/Compiler/Driver/ParseAndCheckInputs.fs

@@ -217,20 +217,15 @@ let PostParseModuleSpec (_i, defaultNamespace, isLastCompiland, fileName, intf)
         SynModuleOrNamespaceSig(lid, isRecursive, kind, decls, xmlDoc, attributes, None, range, trivia)
 
 let GetScopedPragmasForHashDirective hd (langVersion: LanguageVersion) =
-    let supportsNonStringArguments =
-        langVersion.SupportsFeature(LanguageFeature.ParsedHashDirectiveArgumentNonQuotes)
-
     [
         match hd with
-        | ParsedHashDirective("nowarn", numbers, m) ->
-            for s in numbers do
+        | ParsedHashDirective("nowarn", args, m) ->
+            for s in args do
                 let warningNumber =
-                    match supportsNonStringArguments, s with
-                    | _, ParsedHashDirectiveArgument.SourceIdentifier _ -> None
-                    | true, ParsedHashDirectiveArgument.LongIdent _ -> None
-                    | true, ParsedHashDirectiveArgument.Int32(n, _) -> GetWarningNumber(m, string n, true)
-                    | true, ParsedHashDirectiveArgument.Ident(s, _) -> GetWarningNumber(m, s.idText, true)
-                    | _, ParsedHashDirectiveArgument.String(s, _, _) -> GetWarningNumber(m, s, true)
+                    match s with
+                    | ParsedHashDirectiveArgument.Int32(n, m) -> GetWarningNumber(m, string n, langVersion, false)
+                    | ParsedHashDirectiveArgument.Ident(s, m) -> GetWarningNumber(m, s.idText, langVersion, false)
+                    | ParsedHashDirectiveArgument.String(s, _, m) -> GetWarningNumber(m, $"\"{s}\"", langVersion, false)
                     | _ -> None
 
                 match warningNumber with
@@ -912,7 +907,9 @@ let ProcessMetaCommandsFromInput
                 state
 
             | ParsedHashDirective("nowarn", hashArguments, m) ->
-                let arguments = parsedHashDirectiveArguments hashArguments tcConfig.langVersion
+                let arguments =
+                    parsedHashDirectiveArgumentsNoCheck hashArguments tcConfig.langVersion
+
                 List.fold (fun state d -> nowarnF state (m, d)) state arguments
 
             | ParsedHashDirective(("reference" | "r") as c, [], m) ->

src/Compiler/Interactive/fsi.fs

@@ -3844,7 +3844,9 @@ type FsiInteractionProcessor
             istate, Completed None
 
         | ParsedHashDirective("nowarn", nowarnArguments, m) ->
-            let numbers = (parsedHashDirectiveArguments nowarnArguments tcConfigB.langVersion)
+            let numbers =
+                (parsedHashDirectiveArgumentsNoCheck nowarnArguments tcConfigB.langVersion)
+
             List.iter (fun (d: string) -> tcConfigB.TurnWarningOff(m, d)) numbers
             istate, Completed None
 

src/Compiler/SyntaxTree/SyntaxTreeOps.fs

@@ -1005,6 +1005,16 @@ let parsedHashDirectiveArguments (input: ParsedHashDirectiveArgument list) (lang
             | false -> None)
         input
 
+let parsedHashDirectiveArgumentsNoCheck (input: ParsedHashDirectiveArgument list) (langVersion: LanguageVersion) =
+    List.choose
+        (function
+        | ParsedHashDirectiveArgument.String(s, _, _) -> Some s
+        | ParsedHashDirectiveArgument.SourceIdentifier(_, v, _) -> Some v
+        | ParsedHashDirectiveArgument.Int32(n, m) -> Some(string n)
+        | ParsedHashDirectiveArgument.Ident(ident, m) -> Some(ident.idText)
+        | ParsedHashDirectiveArgument.LongIdent(ident, m) -> Some(longIdentToString ident))
+        input
+
 let parsedHashDirectiveStringArguments (input: ParsedHashDirectiveArgument list) (_langVersion: LanguageVersion) =
     List.choose
         (function

src/Compiler/SyntaxTree/SyntaxTreeOps.fsi

@@ -322,6 +322,8 @@ val synExprContainsError: inpExpr: SynExpr -> bool
 
 val parsedHashDirectiveArguments: ParsedHashDirectiveArgument list -> LanguageVersion -> string list
 
+val parsedHashDirectiveArgumentsNoCheck: ParsedHashDirectiveArgument list -> LanguageVersion -> string list
+
 val parsedHashDirectiveStringArguments: ParsedHashDirectiveArgument list -> LanguageVersion -> string list
 
 /// 'e1 && e2'

tests/FSharp.Compiler.ComponentTests/CompilerDirectives/NonStringArgs.fs

@@ -24,15 +24,20 @@ module NonStringArgs =
         |> asExe
         |> compile
         |> shouldFail
-        |> withDiagnostics[
+        |> withDiagnostics [
             if languageVersion = "8.0" then
-                (Warning 203, Line 6, Col 1, Line 6, Col 13, "Invalid warning number 'FS'")
                 (Error 3350, Line 3, Col 9, Line 3, Col 11, "Feature '# directives with non-quoted string arguments' is not available in F# 8.0. Please use language version 9.0 or greater.")
                 (Error 3350, Line 4, Col 9, Line 4, Col 15, "Feature '# directives with non-quoted string arguments' is not available in F# 8.0. Please use language version 9.0 or greater.")
                 (Error 3350, Line 5, Col 9, Line 5, Col 13, "Feature '# directives with non-quoted string arguments' is not available in F# 8.0. Please use language version 9.0 or greater.")
+                (Warning 203, Line 6, Col 9, Line 6, Col 13, """Invalid warning number '"FS"'""");
+                (Warning 203, Line 7, Col 9, Line 7, Col 17, """Invalid warning number '"FSBLAH"'""");
             else
-                (Warning 203, Line 3, Col 1, Line 3, Col 11, "Invalid warning number 'FS'")
-                (Warning 203, Line 6, Col 1, Line 6, Col 13, "Invalid warning number 'FS'")
+                (Warning 203, Line 3, Col 9, Line 3, Col 11, "Invalid warning number 'FS'");
+                (Warning 203, Line 4, Col 9, Line 4, Col 15, "Invalid warning number 'FSBLAH'");
+                (Warning 203, Line 5, Col 9, Line 5, Col 13, "Invalid warning number 'ACME'");
+                (Warning 203, Line 6, Col 9, Line 6, Col 13, """Invalid warning number '"FS"'""");
+                (Warning 203, Line 7, Col 9, Line 7, Col 17, """Invalid warning number '"FSBLAH"'""");
+                (Warning 203, Line 8, Col 9, Line 8, Col 15, """Invalid warning number '"ACME"'""")
             ]
 
 
@@ -55,14 +60,20 @@ module NonStringArgs =
         |> asExe
         |> compile
         |> shouldFail
-        |> withDiagnostics[
+        |> withDiagnostics [
             if languageVersion = "8.0" then
-                (Warning 203, Line 2, Col 1, Line 9, Col 11, "Invalid warning number 'FS'")
                 (Error 3350, Line 4, Col 5, Line 4, Col 7, "Feature '# directives with non-quoted string arguments' is not available in F# 8.0. Please use language version 9.0 or greater.")
                 (Error 3350, Line 5, Col 5, Line 5, Col 11, "Feature '# directives with non-quoted string arguments' is not available in F# 8.0. Please use language version 9.0 or greater.")
                 (Error 3350, Line 6, Col 5, Line 6, Col 9, "Feature '# directives with non-quoted string arguments' is not available in F# 8.0. Please use language version 9.0 or greater.")
+                (Warning 203, Line 7, Col 5, Line 7, Col 9, """Invalid warning number '"FS"'""");
+                (Warning 203, Line 8, Col 5, Line 8, Col 13, """Invalid warning number '"FSBLAH"'""");
             else
-                (Warning 203, Line 2, Col 1, Line 9, Col 11, "Invalid warning number 'FS'")
+                (Warning 203, Line 4, Col 5, Line 4, Col 7, "Invalid warning number 'FS'");
+                (Warning 203, Line 5, Col 5, Line 5, Col 11, "Invalid warning number 'FSBLAH'");
+                (Warning 203, Line 6, Col 5, Line 6, Col 9, "Invalid warning number 'ACME'");
+                (Warning 203, Line 7, Col 5, Line 7, Col 9, """Invalid warning number '"FS"'""");
+                (Warning 203, Line 8, Col 5, Line 8, Col 13, """Invalid warning number '"FSBLAH"'""");
+                (Warning 203, Line 9, Col 5, Line 9, Col 11, """Invalid warning number '"ACME"'""")
             ]
 
 
@@ -81,12 +92,18 @@ module NonStringArgs =
         |> shouldFail
         |> withDiagnostics [
             if languageVersion = "8.0" then
-                (Warning 203, Line 3, Col 1, Line 3, Col 44, "Invalid warning number 'FS'")
                 (Error 3350, Line 3, Col 9, Line 3, Col 11, "Feature '# directives with non-quoted string arguments' is not available in F# 8.0. Please use language version 9.0 or greater.")
                 (Error 3350, Line 3, Col 12, Line 3, Col 18, "Feature '# directives with non-quoted string arguments' is not available in F# 8.0. Please use language version 9.0 or greater.")
                 (Error 3350, Line 3, Col 19, Line 3, Col 23, "Feature '# directives with non-quoted string arguments' is not available in F# 8.0. Please use language version 9.0 or greater.")
+                (Warning 203, Line 3, Col 24, Line 3, Col 28, """Invalid warning number '"FS"'""");
+                (Warning 203, Line 3, Col 29, Line 3, Col 37, """Invalid warning number '"FSBLAH"'""");
             else
-                (Warning 203, Line 3, Col 1, Line 3, Col 44, "Invalid warning number 'FS'")
+                (Warning 203, Line 3, Col 9, Line 3, Col 11, "Invalid warning number 'FS'");
+                (Warning 203, Line 3, Col 12, Line 3, Col 18, "Invalid warning number 'FSBLAH'");
+                (Warning 203, Line 3, Col 19, Line 3, Col 23, "Invalid warning number 'ACME'");
+                (Warning 203, Line 3, Col 24, Line 3, Col 28, """Invalid warning number '"FS"'""");
+                (Warning 203, Line 3, Col 29, Line 3, Col 37, """Invalid warning number '"FSBLAH"'""");
+                (Warning 203, Line 3, Col 38, Line 3, Col 44, """Invalid warning number '"ACME"'""")
             ]
 
 
@@ -128,12 +145,34 @@ module DoBinding =
                 (Warning 1104, Line 5, Col 15, Line 5, Col 31, "Identifiers containing '@' are reserved for use in F# code generation")
                 (Error 3350, Line 2, Col 9, Line 2, Col 11, "Feature '# directives with non-quoted string arguments' is not available in F# 8.0. Please use language version 9.0 or greater.")
                 (Error 3350, Line 2, Col 12, Line 2, Col 18, "Feature '# directives with non-quoted string arguments' is not available in F# 8.0. Please use language version 9.0 or greater.")
+                (Warning 203, Line 2, Col 26, Line 2, Col 34, """Invalid warning number '"FS3221"'""")
                 ]
         else
             compileResult
             |> shouldSucceed
 
 
+    [<InlineData("8.0")>]
+    [<InlineData("9.0")>]
+    [<Theory>]
+    let ``#nowarn - errors - compiler options`` (languageVersion) =
+
+        FSharp """
+match None with None -> ()      // creates FS0025 - ignored due to flag
+""                              // creates FS0020 - ignored due to flag
+        """                     // creates FS0988 - not ignored, different flag prefix
+        |> withLangVersion languageVersion
+        |> withOptions ["--nowarn:NU0988"; "--nowarn:FS25"; "--nowarn:20"; "--nowarn:FS"; "--nowarn:FSBLAH"]
+        |> asExe
+        |> compile
+        |> shouldFail
+        |> withDiagnostics [
+                (Warning 203, Line 0, Col 1, Line 0, Col 1, "Invalid warning number 'FS'")
+                (Warning 203, Line 0, Col 1, Line 0, Col 1, "Invalid warning number 'FSBLAH'")
+                (Warning 988, Line 3, Col 3, Line 3, Col 3, "Main module of program is empty: nothing will happen when it is run")
+            ]
+
+
     [<InlineData("8.0")>]
     [<InlineData("9.0")>]
     [<Theory>]
@@ -248,7 +287,7 @@ printfn "Hello, World"
         |> asExe
         |> compile
         |> shouldFail
-        |> withDiagnostics[
+        |> withDiagnostics [
             (Error 76, Line 2, Col 9, Line 2, Col 11, "This directive may only be used in F# script files (extensions .fsx or .fsscript). Either remove the directive, move this code to a script file or delimit the directive with '#if INTERACTIVE'/'#endif'.")
             (Error 76, Line 3, Col 9, Line 3, Col 14, "This directive may only be used in F# script files (extensions .fsx or .fsscript). Either remove the directive, move this code to a script file or delimit the directive with '#if INTERACTIVE'/'#endif'.")
             (Error 76, Line 4, Col 9, Line 4, Col 17, "This directive may only be used in F# script files (extensions .fsx or .fsscript). Either remove the directive, move this code to a script file or delimit the directive with '#if INTERACTIVE'/'#endif'.")