fix 4715 (#12910)

Author: dsyme

src/fsharp/IlxGen.fs

@@ -1250,16 +1250,12 @@ let ComputeFieldSpecForVal(optIntraAssemblyInfo: IlxGenIntraAssemblyInfo option,
     match optIntraAssemblyInfo with
     | None -> generate()
     | Some intraAssemblyInfo ->
-        if vspec.IsMutable && vspec.IsCompiledAsTopLevel && isStructTy g vspec.Type then
-            let ok, res = intraAssemblyInfo.StaticFieldInfo.TryGetValue ilGetterMethRef
-            if ok then
-                res
-            else
-                let res = generate()
-                intraAssemblyInfo.StaticFieldInfo.[ilGetterMethRef] <- res
-                res
-        else
-            generate()
+        match intraAssemblyInfo.StaticFieldInfo.TryGetValue ilGetterMethRef with
+        | true, res -> res
+        | _ ->
+            let res = generate()
+            intraAssemblyInfo.StaticFieldInfo.[ilGetterMethRef] <- res
+            res
 
 /// Compute the representation information for an F#-declared value (not a member nor a function).
 /// Mutable and literal static fields must have stable names and live in the "public" location

tests/fsharp/regression/4715/date.fs

@@ -0,0 +1,27 @@
+#light
+[<RequireQualifiedAccess>]
+module app.date
+
+open System
+open System.Threading
+
+type T = private T of DateTime
+
+let mutable private _today = None
+
+let set_today (dt:DateTime) = Interlocked.Exchange(&_today, Some (T dt.Date))
+
+let today () =
+    match _today with
+    | Some d -> d
+    | None -> T DateTime.Today.Date
+
+let yesterday () =
+    let today = DateTime.Today.Date
+    T (today - TimeSpan(1, 0, 0, 0))
+
+let inline private unwrap (T d) = d
+
+let fromdt (dt:DateTime) = T dt.Date
+
+let year d = (unwrap d).Year

tests/fsharp/regression/4715/env.fs

@@ -0,0 +1,36 @@
+#light
+[<RequireQualifiedAccess>]
+module app.env
+
+open System
+//open System.Runtime.CompilerServices
+open System.Threading
+
+let mutable private _processing_date:date.T option = None
+let mutable private _irs_received_date:date.T option = None
+
+//[<MethodImpl (MethodImplOptions.NoInlining)>]
+let set_processing_date d = Interlocked.Exchange(&_processing_date, Some d)
+
+//[<MethodImpl (MethodImplOptions.NoInlining)>]
+let set_irs_received_dt d = Interlocked.Exchange(&_irs_received_date, Some d)
+
+let processing_date () =
+    match _processing_date with
+    | Some d -> d
+    | None -> date.fromdt DateTime.Today
+
+let processing_year () =
+    let d = processing_date ()
+    date.year d
+
+let tax_year () =
+    let yr = processing_year ()
+    yr - 1
+
+let irs_received_date () = _irs_received_date
+
+let irs_received_date_exn () =
+    match _irs_received_date with
+    | Some d -> d
+    | None -> failwith "env.irs_received_date uninitialized via set_irs_received_dt"

tests/fsharp/regression/4715/main.fs

@@ -0,0 +1,25 @@
+#light
+module app.main
+
+open System
+
+let private init_dates rdate pdate =
+    match rdate with
+    | Some d -> env.set_irs_received_dt d |> ignore
+    | None -> ()
+
+    match pdate with
+    | Some d -> env.set_processing_date d |> ignore
+    | None -> ()
+
+[<EntryPoint>]
+let main argv =
+    try
+        
+        let rdate = Some (date.yesterday ()) 
+        let pdate = Some (date.today () )
+        init_dates rdate pdate
+    with
+     | ex -> eprintfn "Unhandled exception: %s" (ex.ToString()) ; exit 1
+
+    0

tests/fsharp/tests.fs

@@ -2143,6 +2143,11 @@ module RegressionTests =
     [<Test >]
     let ``12383-FSC_OPTIMIZED`` () = singleTestBuildAndRun "regression/12383" FSC_OPTIMIZED
 
+    [<Test >]
+    let ``4715-optimized`` () =
+        let cfg = testConfig "regression/4715"
+        fsc cfg "%s -o:test.exe --optimize+" cfg.fsc_flags ["date.fs"; "env.fs"; "main.fs"]
+
 #if NETCOREAPP
     [<Test >]
     let ``Large inputs 12322 fsc.dll 64-bit fsc.dll .NET SDK generating optimized code`` () =