Emitting IsReadOnly/In attributes on abstract properties (dotnet#10542)

xamarin · Feb 22, 2021 · e94c59d · e94c59d
1 parent e27cda2
commit e94c59d
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Showing 2 changed files with 43 additions and 5 deletions.
diff --git a/src/fsharp/IlxGen.fs b/src/fsharp/IlxGen.fs
@@ -7129,14 +7129,22 @@ and GenAbstractBinding cenv eenv tref (vref: ValRef) =
     let memberInfo = Option.get vref.MemberInfo
     let attribs = vref.Attribs
     let hasPreserveSigImplFlag, hasSynchronizedImplFlag, hasNoInliningFlag, hasAggressiveInliningImplFlag, attribs = ComputeMethodImplAttribs cenv vref.Deref attribs
-    if memberInfo.MemberFlags.IsDispatchSlot && not memberInfo.IsImplemented then
-        let ilAttrs =
-            [ yield! GenAttrs cenv eenv attribs
-              yield! GenCompilationArgumentCountsAttr cenv vref.Deref ]
-
+    if memberInfo.MemberFlags.IsDispatchSlot && not memberInfo.IsImplemented then    
         let mspec, _mspecW, ctps, mtps, _curriedArgInfos, argInfos, retInfo, witnessInfos, methArgTys, returnTy =
             GetMethodSpecForMemberVal cenv.amap cenv.g memberInfo vref
 
+        let ilAttrs =
+            [ yield! GenAttrs cenv eenv attribs
+              yield! GenCompilationArgumentCountsAttr cenv vref.Deref
+
+              match vref.MemberInfo, returnTy with
+              | Some memberInfo, Some returnTy when 
+                memberInfo.MemberFlags.MemberKind = MemberKind.PropertyGet ||
+                memberInfo.MemberFlags.MemberKind = MemberKind.PropertySet ||
+                memberInfo.MemberFlags.MemberKind = MemberKind.PropertyGetSet ->
+                   match GenReadOnlyAttributeIfNecessary g returnTy with Some ilAttr -> ilAttr | _ -> ()
+              | _ -> () ]
+
         assert witnessInfos.IsEmpty
 
         let eenvForMeth = EnvForTypars (ctps@mtps) eenv
@@ -7175,6 +7183,7 @@ and GenAbstractBinding cenv eenv tref (vref: ValRef) =
              else
                  let ilPropDef =
                      let ilPropTy = GenType cenv.amap m eenvForMeth.tyenv vtyp
+                     let ilPropTy = GenReadOnlyModReqIfNecessary g vtyp ilPropTy
                      let ilArgTys = v |> ArgInfosOfPropertyVal g |> List.map fst |> GenTypes cenv.amap m eenvForMeth.tyenv
                      GenPropertyForMethodDef compileAsInstance tref mdef v memberInfo ilArgTys ilPropTy (mkILCustomAttrs ilAttrs) None
                  let mdef = mdef.WithSpecialName

diff --git a/tests/fsharp/Compiler/Language/ByrefTests.fs b/tests/fsharp/Compiler/Language/ByrefTests.fs
@@ -341,4 +341,33 @@ type C<'T>() =
         FSharp src
         |> compile
         |> verifyIL [verifyMethod]
+        |> ignore
+
+    [<Test>]
+    let ``Returning an 'inref<_>' from an abstract property should emit System.Runtime.CompilerServices.IsReadOnlyAttribute on the return type of the signature`` () =
+        let src =
+            """
+module Test
+
+type C =
+    abstract X: inref<int> 
+            """
+
+        let verifyProperty = """.property instance int32& modreq([runtime]System.Runtime.InteropServices.InAttribute)
+                X()
+        {
+          .custom instance void [runtime]System.Runtime.CompilerServices.IsReadOnlyAttribute::.ctor() = ( 01 00 00 00 ) 
+          .get instance int32& modreq([runtime]System.Runtime.InteropServices.InAttribute) Test/C::get_X()
+        }"""
+
+        let verifyMethod = """.method public hidebysig specialname abstract virtual
+                instance int32& modreq([runtime]System.Runtime.InteropServices.InAttribute) 
+                get_X() cil managed
+        {
+          .param [0]
+          .custom instance void [runtime]System.Runtime.CompilerServices.IsReadOnlyAttribute::.ctor() = ( 01 00 00 00 )"""
+
+        FSharp src
+        |> compile
+        |> verifyIL [verifyProperty;verifyMethod]
         |> ignore