Fix virtual static call (dotnet#17013)

* Fix calling virtual static methods via interface

* InterfaceTests: fix test label and minor code cleanup

* 8.0.300: add fix to release notes

* InterfaceTests: fix braces in quoted code

* StaticsInInterfaces: clarify test cases on virtual static

* StaticsInInterfaces: test SRTP works with overridden virtual static methods

* StaticInInterfaces: add back white spaces

Required for IL comparison.

* Release notes

* Update 8.0.400.md

* Update 8.0.400.md

---------

Co-authored-by: Kevin Ransom (msft) <[email protected]>
Co-authored-by: Vlad Zarytovskii <[email protected]>
Co-authored-by: Petr <[email protected]>

docs/release-notes/.FSharp.Compiler.Service/8.0.400.md

@@ -2,3 +2,4 @@
 
 * Various parenthesization API fixes. ([PR #16977](https://github.com/dotnet/fsharp/pull/16977)) 
 * Fix bug in optimization of for-loops over integral ranges with steps and units of measure. ([Issue #17025](https://github.com/dotnet/fsharp/issues/17025), [PR #17040](https://github.com/dotnet/fsharp/pull/17040))
+* Fix calling an overridden virtual static method via the interface ([PR #17013](https://github.com/dotnet/fsharp/pull/17013))

src/Compiler/Checking/MethodCalls.fs

@@ -906,8 +906,8 @@ let IsBaseCall objArgs =
 /// For example, when calling an interface method on a struct, or a method on a constrained 
 /// variable type. 
 let ComputeConstrainedCallInfo g amap m staticTyOpt args (minfo: MethInfo) =
-    match args, staticTyOpt with 
-    | _, Some staticTy when not minfo.IsExtensionMember && not minfo.IsInstance && minfo.IsAbstract -> Some staticTy
+    match args, staticTyOpt with
+    | _, Some staticTy when not minfo.IsExtensionMember && not minfo.IsInstance && (minfo.IsAbstract || minfo.IsVirtual) -> Some staticTy
 
     | (objArgExpr :: _), _ when minfo.IsInstance && not minfo.IsExtensionMember -> 
         let methObjTy = minfo.ApparentEnclosingType

tests/FSharp.Compiler.ComponentTests/Interop/StaticsInInterfaces.fs

@@ -606,6 +606,49 @@ module Test =
 #endif
         ]
 
+    [<FactForNETCOREAPP>]
+    let ``F# can call overwritten static virtual member from interface``() =
+        let CSharpLib =
+            CSharp """
+namespace Test;
+
+public interface I
+{
+    static virtual string Echo(string x) => $"I.Echo: {x}";
+}
+            """
+            |> withCSharpLanguageVersion CSharpLanguageVersion.CSharp11
+            |> withName "CsLibAssembly"
+
+        FSharp """
+type Imp() =
+    interface Test.I with
+        static member Echo (x: string) = $"Imp.I.Echo: {x}"
+
+    static member Echo (x: string) = $"Imp.Echo: {x}"
+
+let echo<'T when 'T :> Test.I> x = 'T.Echo(x)
+
+let inline echo_srtp<'T when 'T : (static member Echo: string -> string)> x = 'T.Echo(x)
+
+match echo<Imp> "a" with
+| "Imp.I.Echo: a" -> printfn "success"
+| "Imp.Echo: a" -> failwith "incorrectly invoked the class 'Echo'"
+| "I.Echo: a" -> failwith "incorrectly invoked the base interface 'Echo'"
+| _ -> failwith "incorrect value"
+
+match echo_srtp<Imp> "a" with
+| "Imp.Echo: a" -> printfn "success"
+| "Imp.I.Echo: a" -> failwith "incorrectly invoked the interface 'Echo'"
+| "I.Echo: a" -> failwith "incorrectly invoked the base interface 'Echo'"
+| _ -> failwith "incorrect value"
+"""
+        |> withReferences [CSharpLib]
+        |> withLangVersion80
+        |> asExe
+        |> compileAndRun
+        |> shouldSucceed
+
     [<FactForNETCOREAPP>]
     let ``C# can call constrained method defined in F#`` () =
         let FSharpLib =

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

@@ -4,8 +4,8 @@ open Xunit
 open FSharp.Test.Compiler
 
 [<Fact>]
-let ``Concrete instance method is not allowed in interfaces in lang preview``() =
-    FSharp $"""
+let ``Concrete instance method is not allowed in interfaces in lang version80``() =
+    FSharp """
 [<Interface>]
 type I =
     member _.X () = 1
@@ -18,8 +18,8 @@ type I =
     ]
 
 [<Fact>]
-let ``Concrete instance property is not allowed in interfaces in lang preview``() =
-    FSharp $"""
+let ``Concrete instance property is not allowed in interfaces in lang version80``() =
+    FSharp """
 [<Interface>]
 type I =
     member _.Prop = "x"
@@ -32,8 +32,8 @@ type I =
     ]
 
 [<Fact>]
-let ``Concrete static members are allowed in interfaces in lang preview``() =
-    FSharp $"""
+let ``Concrete static members are allowed in interfaces in lang version80``() =
+    FSharp """
 [<Interface>]
 type I<'T> =
     static member Echo (x: 'T) = x
@@ -49,7 +49,7 @@ if I<int>.Echo 42 <> 42 || I<int>.Prop <> 0 || not (isNull I<string>.Prop) then
 
 [<Fact>]
 let ``Concrete static members are not allowed in interfaces in lang version70``() =
-    FSharp $"""
+    FSharp """
 [<Interface>]
 type I<'T> =
     static member Echo (x: 'T) = x
@@ -63,8 +63,8 @@ type I<'T> =
     ]
 
 [<Fact>]
-let ``Concrete static members are allowed in interfaces as intrinsics in lang preview``() =
-    FSharp $"""
+let ``Concrete static members are allowed in interfaces as intrinsics in lang version80``() =
+    FSharp """
 [<Interface>]
 type I<'T> = 
     static member Prop = Unchecked.defaultof<'T>
@@ -81,8 +81,8 @@ if I<int>.Echo 42 <> 42 || I<int>.Prop <> 0 || not (isNull I<string>.Prop) then
 
 
 [<Fact>]
-let ``Interface with concrete static members can be implemented in lang preview``() =
-    FSharp $"""
+let ``Interface with concrete static members can be implemented in lang version80``() =
+    FSharp """
 [<Interface>]
 type I =
     static member Echo (x: string) = x
@@ -92,12 +92,12 @@ type Imp () =
     interface I with
         member _.Blah = 3
 
-let o = {{ new I with member _.Blah = 4 }}
+let o = { new I with member _.Blah = 4 }
 
 if I.Echo "yup" <> "yup" || (Imp() :> I).Blah <> 3 || o.Blah <> 4 then
     failwith "failed"
     """
     |> withLangVersion80
     |> asExe
     |> compileAndRun
-    |> shouldSucceed
+    |> shouldSucceed