Warning or error is raised when consuming IL Event with an Obsolete attribute

src/Compiler/Checking/AttributeChecking.fs

@@ -412,6 +412,9 @@ let CheckEntityAttributes g (tcref: TyconRef) m =
         CheckILAttributes g (isByrefLikeTyconRef g m tcref) tcref.ILTyconRawMetadata.CustomAttrs m
     else 
         CheckFSharpAttributes g tcref.Attribs m
+
+let CheckILEventAttributes g (tcref: TyconRef) cattrs m  =    
+    CheckILAttributes g (isByrefLikeTyconRef g m tcref) cattrs m 
 
 /// Check the attributes associated with a method, returning warnings and errors as data.
 let CheckMethInfoAttributes g m tyargsOpt (minfo: MethInfo) = 

src/Compiler/Checking/AttributeChecking.fsi

@@ -101,3 +101,5 @@ val IsSecurityAttribute:
 val IsSecurityCriticalAttribute: g: TcGlobals -> Attrib -> bool
 
 val IsAssemblyVersionAttribute: g: TcGlobals -> Attrib -> bool
+
+val CheckILEventAttributes: g: TcGlobals -> tcref: TyconRef -> cattrs: ILAttributes -> m: range -> OperationResult<unit>

src/Compiler/Checking/CheckExpressions.fs

@@ -9095,7 +9095,9 @@ and TcEventItemThen (cenv: cenv) overallTy env tpenv mItem mExprAndItem objDetai
     let (SigOfFunctionForDelegate(delInvokeMeth, delArgTys, _, _)) = GetSigOfFunctionForDelegate cenv.infoReader delTy mItem ad
     let objArgs = Option.toList (Option.map fst objDetails)
     MethInfoChecks g cenv.amap true None objArgs env.eAccessRights mItem delInvokeMeth
-
+
+    CheckILEventAttributes g einfo.DeclaringTyconRef (einfo.GetCustomAttrs()) mItem |> CommitOperationResult
+
     // This checks for and drops the 'object' sender
     let argsTy = ArgsTypeOfEventInfo cenv.infoReader mItem ad einfo
     if not (slotSigHasVoidReturnTy (delInvokeMeth.GetSlotSig(cenv.amap, mItem))) then errorR (nonStandardEventError einfo.EventName mItem)

src/Compiler/Checking/infos.fs

@@ -2275,6 +2275,12 @@ type EventInfo =
         | ProvidedEvent (_, ei, _) -> ProvidedEventInfo.TaintedGetHashCode ei
 #endif
     override x.ToString() = "event " + x.EventName
+
+    /// Get custom attributes for events (only applicable for IL events)
+    member x.GetCustomAttrs() =
+        match x with
+        | ILEvent(ILEventInfo(_, ilEventDef))-> ilEventDef.CustomAttrs
+        | _ -> ILAttributes.Empty
 
 //-------------------------------------------------------------------------
 // Helpers associated with getting and comparing method signatures

src/Compiler/Checking/infos.fsi

@@ -1009,6 +1009,9 @@ type EventInfo =
     /// Get the delegate type associated with the event.
     member GetDelegateType: amap: ImportMap * m: range -> TType
 
+    /// Get custom attributes for events (only applicable for IL events)
+    member GetCustomAttrs: unit -> ILAttributes
+
 /// An exception type used to raise an error using the old error system.
 ///
 /// Error text: "A definition to be compiled as a .NET event does not have the expected form. Only property members can be compiled as .NET events."

tests/FSharp.Compiler.ComponentTests/Language/ObsoleteAttributeCheckingTests.fs

@@ -917,6 +917,7 @@ Class.ObsoleteEvent |> ignore
             (Warning 44, Line 3, Col 1, Line 3, Col 20, "This construct is deprecated. Field is obsolete");
             (Warning 44, Line 4, Col 1, Line 4, Col 21, "This construct is deprecated. Method is obsolete");
             (Warning 44, Line 5, Col 1, Line 5, Col 23, "This construct is deprecated. Property is obsolete")
+            (Warning 44, Line 6, Col 1, Line 6, Col 20, "This construct is deprecated. Event is obsolete")
         ]
 
     [<Fact>]
@@ -955,4 +956,5 @@ Class.ObsoleteEvent |> ignore
             (Error 101, Line 3, Col 1, Line 3, Col 20, "This construct is deprecated. Field is obsolete");
             (Error 101, Line 4, Col 1, Line 4, Col 21, "This construct is deprecated. Method is obsolete");
             (Error 101, Line 5, Col 1, Line 5, Col 23, "This construct is deprecated. Property is obsolete")
+            (Error 101, Line 6, Col 1, Line 6, Col 20, "This construct is deprecated. Event is obsolete")
         ]