Always write static hidebysig to ref assembly

src/Compiler/AbstractIL/ilwrite.fs

@@ -1151,8 +1151,11 @@ let canGenMethodDef (tdef: ILTypeDef) cenv (mdef: ILMethodDef) =
         match mdef.Access with
         | ILMemberAccess.Public -> true
         // When emitting a reference assembly, do not emit methods that are private/protected/internal unless they are virtual/abstract or provide an explicit interface implementation.
+        // REVIEW: Addded(vlza, fixes #14937):
+        //   We also emit methods that are marked as HideBySig and static,
+        //   since they're not virtual or abstract, but we want (?) the same behaviour as normal instance implementations.
         | ILMemberAccess.Private | ILMemberAccess.Family | ILMemberAccess.Assembly | ILMemberAccess.FamilyOrAssembly
-            when mdef.IsVirtual || mdef.IsAbstract || mdef.IsNewSlot || mdef.IsFinal || mdef.IsEntryPoint -> true
+            when (mdef.IsHideBySig && mdef.IsStatic) || mdef.IsVirtual || mdef.IsAbstract || mdef.IsNewSlot || mdef.IsFinal || mdef.IsEntryPoint -> true
         // When emitting a reference assembly, only generate internal methods if the assembly contains a System.Runtime.CompilerServices.InternalsVisibleToAttribute.
         | ILMemberAccess.FamilyOrAssembly | ILMemberAccess.Assembly
             when cenv.hasInternalsVisibleToAttrib -> true
@@ -2678,7 +2681,7 @@ let GenMethodImplPass3 cenv env _tgparams tidx mimpl =
     let midx2Tag, midx2Row = GetOverridesSpecAsMethodDefOrRef cenv env mimpl.Overrides
     AddUnsharedRow cenv TableNames.MethodImpl
         (UnsharedRow
-             [| SimpleIndex (TableNames.TypeDef, tidx)
+            [|  SimpleIndex (TableNames.TypeDef, tidx)
                 MethodDefOrRef (midxTag, midxRow)
                 MethodDefOrRef (midx2Tag, midx2Row) |]) |> ignore
 

tests/fsharp/Compiler/CodeGen/EmittedIL/ReferenceAssemblyTests.fs

@@ -1404,5 +1404,141 @@ Console.WriteLine("Hello World!")"""
 """
         ]
         |> ignore
+#if NETCOREAPP
+    [<Test>]
+#endif
+    let ``Refassembly_emits_static_abstracts_implementations_the_same_way_it_does_for_instance_with_empty_signature`` () =
+
+        let signature = """namespace Foobar
+type IHasStaticAbstractBase<'a> =
+    static abstract BoomStatic: unit -> 'a
+    abstract BoomInstance: unit -> 'a
+
+type CompilerGoesBoom<'a> =
+    interface IHasStaticAbstractBase<'a>
+    new: unit -> CompilerGoesBoom<'a>"""
+
+        let implementation = """namespace Foobar
+type IHasStaticAbstractBase<'a> =
+    abstract BoomInstance: unit -> 'a
+    static abstract BoomStatic: unit -> 'a
+
+type CompilerGoesBoom<'a>() =
+    interface IHasStaticAbstractBase<'a> with
+        member (*virtual*) this.BoomInstance() = Unchecked.defaultof<'a>
+        static member (*non-virtual*) BoomStatic() = Unchecked.defaultof<'a>
+    """
+
+        Fsi signature
+        |> withAdditionalSourceFile (FsSource implementation)
+        |> withOptions [ "--refonly" ]
+        |> ignoreWarnings
+        |> compile
+        |> shouldSucceed
+        |> verifyIL
+            [
+                referenceAssemblyAttributeExpectedIL
+                """.class interface public abstract auto ansi serializable beforefieldinit Foobar.IHasStaticAbstractBase`1<a>
+{
+  .custom instance void [FSharp.Core]Microsoft.FSharp.Core.CompilationMappingAttribute::.ctor(valuetype [FSharp.Core]Microsoft.FSharp.Core.SourceConstructFlags) = ( 01 00 03 00 00 00 00 00 )
+  .method public hidebysig abstract virtual
+          instance !a  BoomInstance() cil managed
+  {
+  }
+
+  .method public hidebysig static abstract virtual
+          !a  BoomStatic() cil managed
+  {
+  }
+
+}"""
+                """.method private hidebysig newslot virtual
+            instance !a  'Foobar.IHasStaticAbstractBase<\'a>.BoomInstance'() cil managed
+    {
+      .override  method instance !0 class Foobar.IHasStaticAbstractBase`1<!a>::BoomInstance()
+
+      .maxstack  8
+      IL_0000:  ldnull
+      IL_0001:  throw
+    }
+
+    .method assembly hidebysig static !a  'Foobar.IHasStaticAbstractBase<\'a>.BoomStatic'() cil managed
+    {
+      .override  method !0 class Foobar.IHasStaticAbstractBase`1<!a>::BoomStatic()
+
+      .maxstack  8
+      IL_0000:  ldnull
+      IL_0001:  throw
+    }"""
+        ]
+
+
+#if NETCOREAPP
+    [<Test>]
+#endif
+    let ``Refassembly_emits_static_abstracts_implementations_the_same_way_it_does_for_instance_with_signature`` () =
+        let signature = """namespace Foobar
+type IHasStaticAbstractBase<'a> =
+    static abstract BoomStatic: unit -> 'a
+    abstract BoomInstance: unit -> 'a
+
+type CompilerGoesBoom<'a> =
+    interface IHasStaticAbstractBase<'a>
+    new: unit -> CompilerGoesBoom<'a>"""
+
+        let implementation = """namespace Foobar
+type IHasStaticAbstractBase<'a> =
+    abstract BoomInstance: unit -> 'a
+    static abstract BoomStatic: unit -> 'a
+
+type CompilerGoesBoom<'a>() =
+    interface IHasStaticAbstractBase<'a> with
+        member (*virtual*) this.BoomInstance() = Unchecked.defaultof<'a>
+        static member (*non-virtual*) BoomStatic() = Unchecked.defaultof<'a>
+    """
+
+        Fsi signature
+        |> withAdditionalSourceFile (FsSource implementation)
+        |> withOptions ["--refonly"]
+        |> ignoreWarnings
+        |> compile
+        |> shouldSucceed
+        |> verifyIL
+            [
+                referenceAssemblyAttributeExpectedIL
+                """.class interface public abstract auto ansi serializable beforefieldinit Foobar.IHasStaticAbstractBase`1<a>
+{
+  .custom instance void [FSharp.Core]Microsoft.FSharp.Core.CompilationMappingAttribute::.ctor(valuetype [FSharp.Core]Microsoft.FSharp.Core.SourceConstructFlags) = ( 01 00 03 00 00 00 00 00 )
+  .method public hidebysig abstract virtual
+          instance !a  BoomInstance() cil managed
+  {
+  }
+
+  .method public hidebysig static abstract virtual
+          !a  BoomStatic() cil managed
+  {
+  }
+
+}"""
+                """.method private hidebysig newslot virtual
+            instance !a  'Foobar.IHasStaticAbstractBase<\'a>.BoomInstance'() cil managed
+    {
+      .override  method instance !0 class Foobar.IHasStaticAbstractBase`1<!a>::BoomInstance()
+
+      .maxstack  8
+      IL_0000:  ldnull
+      IL_0001:  throw
+    }
+
+    .method assembly hidebysig static !a  'Foobar.IHasStaticAbstractBase<\'a>.BoomStatic'() cil managed
+    {
+      .override  method !0 class Foobar.IHasStaticAbstractBase`1<!a>::BoomStatic()
+
+      .maxstack  8
+      IL_0000:  ldnull
+      IL_0001:  throw
+    }"""
+            ]
+
 
     // TODO: Add tests for internal functions, types, interfaces, abstract types (with and without IVTs), (private, internal, public) fields, properties (+ different visibility for getters and setters), events.