Warn unsupported attributes

src/fsharp/FSComp.txt

@@ -31,6 +31,7 @@ buildUnexpectedTypeArgs,"The non-generic type '%s' does not expect any type argu
 returnUsedInsteadOfReturnBang,"Consider using 'return!' instead of 'return'."
 yieldUsedInsteadOfYieldBang,"Consider using 'yield!' instead of 'yield'."
 tupleRequiredInAbstractMethod,"\nA tuple type is required for one or more arguments. Consider wrapping the given arguments in additional parentheses or review the definition of the interface."
+202,unsupportedAttribute,"This attribute is currently unsupported by the F# compiler. Applying it will not achieve its intended effect."
 203,buildInvalidWarningNumber,"Invalid warning number '%s'"
 204,buildInvalidVersionString,"Invalid version string '%s'"
 205,buildInvalidVersionFile,"Invalid version file '%s'"

src/fsharp/PostInferenceChecks.fs

@@ -1639,7 +1639,9 @@ and CheckDecisionTreeTest cenv env m discrim =
     | DecisionTreeTest.ActivePatternCase (exp, _, _, _, _, _) -> CheckExprNoByrefs cenv env exp
     | DecisionTreeTest.Error _ -> ()
 
-and CheckAttrib cenv env (Attrib(_, _, args, props, _, _, _)) = 
+and CheckAttrib cenv env (Attrib(tcref, _, args, props, _, _, m)) =
+    if List.exists (tyconRefEq cenv.g tcref) cenv.g.attribs_Unsupported then
+        warning(Error(FSComp.SR.unsupportedAttribute(), m))
     props |> List.iter (fun (AttribNamedArg(_, _, _, expr)) -> CheckAttribExpr cenv env expr)
     args |> List.iter (CheckAttribExpr cenv env)
 

src/fsharp/TcGlobals.fs

@@ -1202,6 +1202,10 @@ type public TcGlobals(compilingFslib: bool, ilg:ILGlobals, fslibCcu: CcuThunk, d
   member val attrib_CallerFilePathAttribute = findSysAttrib "System.Runtime.CompilerServices.CallerFilePathAttribute"
   member val attrib_CallerMemberNameAttribute = findSysAttrib "System.Runtime.CompilerServices.CallerMemberNameAttribute"
   member val attrib_SkipLocalsInitAttribute  = findSysAttrib "System.Runtime.CompilerServices.SkipLocalsInitAttribute"
+  member val attribs_Unsupported = [
+        tryFindSysAttrib "System.Runtime.CompilerServices.ModuleInitializerAttribute"
+        tryFindSysAttrib "System.Runtime.CompilerServices.CallerArgumentExpressionAttribute"
+                                   ] |> List.choose (Option.map (fun x -> x.TyconRef))
 
   member val attrib_ProjectionParameterAttribute           = mk_MFCore_attrib "ProjectionParameterAttribute"
   member val attrib_CustomOperationAttribute               = mk_MFCore_attrib "CustomOperationAttribute"

src/fsharp/xlf/FSComp.txt.cs.xlf

@@ -607,6 +607,11 @@
         <target state="translated">Zvažte použití parametru return! namísto return.</target>
         <note />
       </trans-unit>
+      <trans-unit id="unsupportedAttribute">
+        <source>This attribute is currently unsupported by the F# compiler. Applying it will not achieve its intended effect.</source>
+        <target state="new">This attribute is currently unsupported by the F# compiler. Applying it will not achieve its intended effect.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="useSdkRefs">
         <source>Use reference assemblies for .NET framework references when available (Enabled by default).</source>
         <target state="translated">Pro odkazy na rozhraní .NET používejte referenční sestavení, pokud jsou k dispozici (ve výchozím nastavení povolené).</target>

src/fsharp/xlf/FSComp.txt.de.xlf

@@ -607,6 +607,11 @@
         <target state="translated">Verwenden Sie ggf. "return!" anstelle von "return".</target>
         <note />
       </trans-unit>
+      <trans-unit id="unsupportedAttribute">
+        <source>This attribute is currently unsupported by the F# compiler. Applying it will not achieve its intended effect.</source>
+        <target state="new">This attribute is currently unsupported by the F# compiler. Applying it will not achieve its intended effect.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="useSdkRefs">
         <source>Use reference assemblies for .NET framework references when available (Enabled by default).</source>
         <target state="translated">Verweisassemblys für .NET Framework-Verweise verwenden, wenn verfügbar (standardmäßig aktiviert).</target>

src/fsharp/xlf/FSComp.txt.es.xlf

@@ -607,6 +607,11 @@
         <target state="translated">Considere la posibilidad de usar "return!" en lugar de "return".</target>
         <note />
       </trans-unit>
+      <trans-unit id="unsupportedAttribute">
+        <source>This attribute is currently unsupported by the F# compiler. Applying it will not achieve its intended effect.</source>
+        <target state="new">This attribute is currently unsupported by the F# compiler. Applying it will not achieve its intended effect.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="useSdkRefs">
         <source>Use reference assemblies for .NET framework references when available (Enabled by default).</source>
         <target state="translated">Use ensamblados de referencia para las referencias de .NET Framework cuando estén disponibles (habilitado de forma predeterminada).</target>

src/fsharp/xlf/FSComp.txt.fr.xlf

@@ -607,6 +607,11 @@
         <target state="translated">Utilisez 'return!' à la place de 'return'.</target>
         <note />
       </trans-unit>
+      <trans-unit id="unsupportedAttribute">
+        <source>This attribute is currently unsupported by the F# compiler. Applying it will not achieve its intended effect.</source>
+        <target state="new">This attribute is currently unsupported by the F# compiler. Applying it will not achieve its intended effect.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="useSdkRefs">
         <source>Use reference assemblies for .NET framework references when available (Enabled by default).</source>
         <target state="translated">Utilisez des assemblys de référence pour les références .NET Framework quand ils sont disponibles (activé par défaut).</target>

src/fsharp/xlf/FSComp.txt.it.xlf

@@ -607,6 +607,11 @@
         <target state="translated">Provare a usare 'return!' invece di 'return'.</target>
         <note />
       </trans-unit>
+      <trans-unit id="unsupportedAttribute">
+        <source>This attribute is currently unsupported by the F# compiler. Applying it will not achieve its intended effect.</source>
+        <target state="new">This attribute is currently unsupported by the F# compiler. Applying it will not achieve its intended effect.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="useSdkRefs">
         <source>Use reference assemblies for .NET framework references when available (Enabled by default).</source>
         <target state="translated">Usa gli assembly di riferimento per i riferimenti a .NET Framework quando disponibili (abilitato per impostazione predefinita).</target>

src/fsharp/xlf/FSComp.txt.ja.xlf

@@ -607,6 +607,11 @@
         <target state="translated">'return' の代わりに 'return!' を使うことを検討してください。</target>
         <note />
       </trans-unit>
+      <trans-unit id="unsupportedAttribute">
+        <source>This attribute is currently unsupported by the F# compiler. Applying it will not achieve its intended effect.</source>
+        <target state="new">This attribute is currently unsupported by the F# compiler. Applying it will not achieve its intended effect.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="useSdkRefs">
         <source>Use reference assemblies for .NET framework references when available (Enabled by default).</source>
         <target state="translated">使用可能な場合は、.NET Framework リファレンスの参照アセンブリを使用します (既定で有効)。</target>

src/fsharp/xlf/FSComp.txt.ko.xlf

@@ -607,6 +607,11 @@
         <target state="translated">'return'이 아니라 'return!'를 사용하세요.</target>
         <note />
       </trans-unit>
+      <trans-unit id="unsupportedAttribute">
+        <source>This attribute is currently unsupported by the F# compiler. Applying it will not achieve its intended effect.</source>
+        <target state="new">This attribute is currently unsupported by the F# compiler. Applying it will not achieve its intended effect.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="useSdkRefs">
         <source>Use reference assemblies for .NET framework references when available (Enabled by default).</source>
         <target state="translated">기본적으로 활성화되는 참조 어셈블리를 .NET Framework 참조에 사용합니다(사용 가능한 경우).</target>

src/fsharp/xlf/FSComp.txt.pl.xlf

@@ -607,6 +607,11 @@
         <target state="translated">Rozważ użycie polecenia „return!” zamiast „return”.</target>
         <note />
       </trans-unit>
+      <trans-unit id="unsupportedAttribute">
+        <source>This attribute is currently unsupported by the F# compiler. Applying it will not achieve its intended effect.</source>
+        <target state="new">This attribute is currently unsupported by the F# compiler. Applying it will not achieve its intended effect.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="useSdkRefs">
         <source>Use reference assemblies for .NET framework references when available (Enabled by default).</source>
         <target state="translated">Użyj zestawów odwołań dla odwołań do programu .NET Framework, gdy są dostępne (domyślnie włączone).</target>

src/fsharp/xlf/FSComp.txt.pt-BR.xlf

@@ -607,6 +607,11 @@
         <target state="translated">Considere usar 'return!' em vez de 'return'.</target>
         <note />
       </trans-unit>
+      <trans-unit id="unsupportedAttribute">
+        <source>This attribute is currently unsupported by the F# compiler. Applying it will not achieve its intended effect.</source>
+        <target state="new">This attribute is currently unsupported by the F# compiler. Applying it will not achieve its intended effect.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="useSdkRefs">
         <source>Use reference assemblies for .NET framework references when available (Enabled by default).</source>
         <target state="translated">Use assemblies de referência para referências do .NET Framework quando disponível (habilitado por padrão).</target>

src/fsharp/xlf/FSComp.txt.ru.xlf

@@ -607,6 +607,11 @@
         <target state="translated">Рекомендуется использовать "return!" вместо "return".</target>
         <note />
       </trans-unit>
+      <trans-unit id="unsupportedAttribute">
+        <source>This attribute is currently unsupported by the F# compiler. Applying it will not achieve its intended effect.</source>
+        <target state="new">This attribute is currently unsupported by the F# compiler. Applying it will not achieve its intended effect.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="useSdkRefs">
         <source>Use reference assemblies for .NET framework references when available (Enabled by default).</source>
         <target state="translated">Использовать базовые сборки для ссылок на платформу .NET, если базовые сборки доступны (включено по умолчанию).</target>

src/fsharp/xlf/FSComp.txt.tr.xlf

@@ -607,6 +607,11 @@
         <target state="translated">'return' yerine 'return!' kullanmayı deneyin.</target>
         <note />
       </trans-unit>
+      <trans-unit id="unsupportedAttribute">
+        <source>This attribute is currently unsupported by the F# compiler. Applying it will not achieve its intended effect.</source>
+        <target state="new">This attribute is currently unsupported by the F# compiler. Applying it will not achieve its intended effect.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="useSdkRefs">
         <source>Use reference assemblies for .NET framework references when available (Enabled by default).</source>
         <target state="translated">Kullanılabilir olduğunda, .NET Framework başvuruları için başvuru bütünleştirilmiş kodlarını kullanın (Varsayılan olarak etkindir).</target>

src/fsharp/xlf/FSComp.txt.zh-Hans.xlf

@@ -607,6 +607,11 @@
         <target state="translated">考虑使用 "return!"，而非 "return"。</target>
         <note />
       </trans-unit>
+      <trans-unit id="unsupportedAttribute">
+        <source>This attribute is currently unsupported by the F# compiler. Applying it will not achieve its intended effect.</source>
+        <target state="new">This attribute is currently unsupported by the F# compiler. Applying it will not achieve its intended effect.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="useSdkRefs">
         <source>Use reference assemblies for .NET framework references when available (Enabled by default).</source>
         <target state="translated">如果可用，请对 .NET Framework 引用使用引用程序集(默认启用)。</target>

src/fsharp/xlf/FSComp.txt.zh-Hant.xlf

@@ -607,6 +607,11 @@
         <target state="translated">請考慮使用 'return!'，而不使用 'return'。</target>
         <note />
       </trans-unit>
+      <trans-unit id="unsupportedAttribute">
+        <source>This attribute is currently unsupported by the F# compiler. Applying it will not achieve its intended effect.</source>
+        <target state="new">This attribute is currently unsupported by the F# compiler. Applying it will not achieve its intended effect.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="useSdkRefs">
         <source>Use reference assemblies for .NET framework references when available (Enabled by default).</source>
         <target state="translated">請在可行的情況下使用適用於 .NET 架構參考的參考組件 (預設會啟用)。</target>

tests/FSharp.Compiler.ComponentTests/ErrorMessages/UnsupportedAttributes.fs

@@ -0,0 +1,55 @@
+// Copyright (c) Microsoft Corporation.  All Rights Reserved.  See License.txt in the project root for license information.
+
+namespace FSharp.Compiler.ComponentTests.ErrorMessages
+
+#if NETCOREAPP
+open Xunit
+open FSharp.Test.Utilities.Compiler
+
+module ``Unsupported Attributes`` =
+
+    [<Fact>]
+    let ``Warn successfully`` () =
+        """
+open System.Runtime.CompilerServices
+let f (w, [<CallerArgumentExpression "w">] x : string) = ()
+let [<ModuleInitializer>] g () = ()
+type C() =
+    member _.F (w, [<System.Runtime.CompilerServices.CallerArgumentExpression "w">] x : string) = ()
+    [<System.Runtime.CompilerServices.ModuleInitializer>]
+    member _.G() = ()
+        """
+        |> FSharp
+        |> typecheck
+        |> shouldFail
+        |> withResults [
+            { Error = Warning 202
+              Range = { StartLine = 3
+                        StartColumn = 13
+                        EndLine = 3
+                        EndColumn = 37 }
+              Message =
+               "This attribute is currently unsupported by the F# compiler. Applying it will not achieve its intended effect." }
+            { Error = Warning 202
+              Range = { StartLine = 4
+                        StartColumn = 7
+                        EndLine = 4
+                        EndColumn = 24 }
+              Message =
+               "This attribute is currently unsupported by the F# compiler. Applying it will not achieve its intended effect." }
+            { Error = Warning 202
+              Range = { StartLine = 6
+                        StartColumn = 22
+                        EndLine = 6
+                        EndColumn = 78 }
+              Message =
+               "This attribute is currently unsupported by the F# compiler. Applying it will not achieve its intended effect." }
+            { Error = Warning 202
+              Range = { StartLine = 7
+                        StartColumn = 7
+                        EndLine = 7
+                        EndColumn = 56 }
+              Message =
+               "This attribute is currently unsupported by the F# compiler. Applying it will not achieve its intended effect." }
+        ]
+#endif

tests/FSharp.Compiler.ComponentTests/FSharp.Compiler.ComponentTests.fsproj

@@ -26,6 +26,7 @@
     <Compile Include="EmittedIL\StringFormatAndInterpolation.fs" />
     <Compile Include="EmittedIL\TailCalls.fs" />
     <Compile Include="EmittedIL\TupleElimination.fs" />
+    <Compile Include="ErrorMessages\UnsupportedAttributes.fs" />
     <Compile Include="ErrorMessages\TypeEqualsMissingTests.fs" />
     <Compile Include="ErrorMessages\AccessOfTypeAbbreviationTests.fs" />
     <Compile Include="ErrorMessages\AssignmentErrorTests.fs" />