Bugfix : Struct DU with DefaultAugment(false) and a non-nullary field (…

…#16326) * fix bug with defaultaugment(false) * without newline * Making sure that nullary case works
dotnet · Nov 23, 2023 · 363e876 · 363e876
1 parent 2a25184
commit 363e876
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Showing 2 changed files with 70 additions and 45 deletions.
diff --git a/src/Compiler/CodeGen/EraseUnions.fs b/src/Compiler/CodeGen/EraseUnions.fs
@@ -751,6 +751,53 @@ let convAlternativeDef
     // within FSharp.Core.dll on fresh unpublished cons cells.
     let isTotallyImmutable = (cud.HasHelpers <> SpecialFSharpListHelpers)
 
+    let makeNonNullaryMakerMethod () =
+        let locals, ilInstrs =
+            if repr.RepresentAlternativeAsStructValue info then
+                let local = mkILLocal baseTy None
+                let ldloca = I_ldloca(0us)
+
+                let ilInstrs =
+                    [
+                        ldloca
+                        ILInstr.I_initobj baseTy
+                        if (repr.DiscriminationTechnique info) = IntegerTag && num <> 0 then
+                            ldloca
+                            mkLdcInt32 num
+                            mkSetTagToField g.ilg cuspec baseTy
+                        for i in 0 .. fields.Length - 1 do
+                            ldloca
+                            mkLdarg (uint16 i)
+                            mkNormalStfld (mkILFieldSpecInTy (baseTy, fields[i].LowerName, fields[i].Type))
+                        mkLdloc 0us
+                    ]
+
+                [ local ], ilInstrs
+            else
+                let ilInstrs =
+                    [
+                        for i in 0 .. fields.Length - 1 do
+                            mkLdarg (uint16 i)
+                        yield! convNewDataInstrInternal g.ilg cuspec num
+                    ]
+
+                [], ilInstrs
+
+        let mdef =
+            mkILNonGenericStaticMethod (
+                mkMakerName cuspec altName,
+                cud.HelpersAccessibility,
+                fields
+                |> Array.map (fun fd -> mkILParamNamed (fd.LowerName, fd.Type))
+                |> Array.toList,
+                mkILReturn baseTy,
+                mkMethodBody (true, locals, fields.Length + locals.Length, nonBranchingInstrsToCode ilInstrs, attr, imports)
+            )
+            |> addMethodGeneratedAttrs
+            |> addAltAttribs
+
+        mdef
+
     let altUniqObjMeths =
 
         // This method is only generated if helpers are not available. It fetches the unique object for the alternative
@@ -885,54 +932,13 @@ let convAlternativeDef
                     [ nullaryMeth ], [ nullaryProp ]
 
                 else
-                    let locals, ilInstrs =
-                        if repr.RepresentAlternativeAsStructValue info then
-                            let local = mkILLocal baseTy None
-                            let ldloca = I_ldloca(0us)
-
-                            let ilInstrs =
-                                [
-                                    ldloca
-                                    ILInstr.I_initobj baseTy
-                                    if (repr.DiscriminationTechnique info) = IntegerTag && num <> 0 then
-                                        ldloca
-                                        mkLdcInt32 num
-                                        mkSetTagToField g.ilg cuspec baseTy
-                                    for i in 0 .. fields.Length - 1 do
-                                        ldloca
-                                        mkLdarg (uint16 i)
-                                        mkNormalStfld (mkILFieldSpecInTy (baseTy, fields[i].LowerName, fields[i].Type))
-                                    mkLdloc 0us
-                                ]
-
-                            [ local ], ilInstrs
-                        else
-                            let ilInstrs =
-                                [
-                                    for i in 0 .. fields.Length - 1 do
-                                        mkLdarg (uint16 i)
-                                    yield! convNewDataInstrInternal g.ilg cuspec num
-                                ]
-
-                            [], ilInstrs
-
-                    let mdef =
-                        mkILNonGenericStaticMethod (
-                            mkMakerName cuspec altName,
-                            cud.HelpersAccessibility,
-                            fields
-                            |> Array.map (fun fd -> mkILParamNamed (fd.LowerName, fd.Type))
-                            |> Array.toList,
-                            mkILReturn baseTy,
-                            mkMethodBody (true, locals, fields.Length + locals.Length, nonBranchingInstrsToCode ilInstrs, attr, imports)
-                        )
-                        |> addMethodGeneratedAttrs
-                        |> addAltAttribs
-
-                    [ mdef ], []
+                    [ makeNonNullaryMakerMethod () ], []
 
             (baseMakerMeths @ baseTesterMeths), (baseMakerProps @ baseTesterProps)
 
+        | NoHelpers when not (alt.IsNullary) && cuspecRepr.RepresentAlternativeAsStructValue(cuspec) ->
+            // For non-nullary struct DUs, maker method is used to create their values.
+            [ makeNonNullaryMakerMethod () ], []
         | NoHelpers -> [], []
 
     let typeDefs, altDebugTypeDefs, altNullaryFields =

diff --git a/tests/FSharp.Compiler.ComponentTests/Conformance/Types/UnionTypes/UnionStructTypes.fs b/tests/FSharp.Compiler.ComponentTests/Conformance/Types/UnionTypes/UnionStructTypes.fs
@@ -701,6 +701,25 @@ type GenericStructDu<'T> = EmptyFirst | SingleVal of f:'T | DoubleVal of f2:'T *
         |> compile
         |> shouldSucceed
 
+    [<Fact>]
+    let ``Regression 16282 DefaultAugment false on a struct union with fields`` ()  =
+        Fsx """
+[<Struct>]
+[<DefaultAugmentation(false)>]
+type Foo =
+    | Baz of int
+    | Bat
+    | Batman
+
+
+let foo = [Baz 42; Bat; Batman]
+printf "%A" foo"""
+        |> asExe
+        |> compile
+        |> shouldSucceed
+        |> run
+        |> verifyOutput "[Baz 42; Bat; Batman]"
+
     [<Fact>]
     let ``Struct DU ValueOption keeps working`` ()  =
         Fsx """