Merge main to release/dev17.12

DEVGUIDE.md

@@ -215,6 +215,17 @@ or
 > **Note**
 > Please note, that by default, **Release** version of IL baseline tests will be running in CI, so when updating baseline (.bsl) files, make sure to add `-c Release` flag to the build command.
 
+
+### Updating FCS surface area baselines
+
+```bash
+$env:TEST_UPDATE_BSL=1
+dotnet test tests/FSharp.Compiler.Service.Tests/FSharp.Compiler.Service.Tests.fsproj --filter "SurfaceAreaTest" /p:BUILDING_USING_DOTNET=true
+dotnet test tests/FSharp.Compiler.Service.Tests/FSharp.Compiler.Service.Tests.fsproj --filter "SurfaceAreaTest" /p:BUILDING_USING_DOTNET=true
+dotnet test tests/FSharp.Compiler.Service.Tests/FSharp.Compiler.Service.Tests.fsproj --filter "SurfaceAreaTest" -c Release /p:BUILDING_USING_DOTNET=true
+dotnet test tests/FSharp.Compiler.Service.Tests/FSharp.Compiler.Service.Tests.fsproj --filter "SurfaceAreaTest" -c Release /p:BUILDING_USING_DOTNET=true
+```
+
 ## Automated Source Code Formatting
 
 Some of the code in this repository is formatted automatically by [Fantomas](https://github.com/fsprojects/fantomas). To format all files use:

docs/release-notes/.FSharp.Compiler.Service/9.0.100.md

@@ -15,7 +15,7 @@
 * Parser: recover on missing union case fields (PR [#17452](https://github.com/dotnet/fsharp/pull/17452))
 * Parser: recover on missing union case field types (PR [#17455](https://github.com/dotnet/fsharp/pull/17455))
 * Sink: report function domain type ([PR #17470](https://github.com/dotnet/fsharp/pull/17470))
-* Allow access modifies to auto properties getters and setters ([PR 16687](https://github.com/dotnet/fsharp/pull/16687), [PR 16861](https://github.com/dotnet/fsharp/pull/16861), [Language suggestion #430](https://github.com/fsharp/fslang-suggestions/issues/430))
+* Allow access modifies to auto properties getters and setters ([Language suggestion #430](https://github.com/fsharp/fslang-suggestions/issues/430), [PR 16687](https://github.com/dotnet/fsharp/pull/16687), [PR 16861](https://github.com/dotnet/fsharp/pull/16861), [PR 17522](https://github.com/dotnet/fsharp/pull/17522))
 * Render C# nullable-analysis attributes in tooltips ([PR #17485](https://github.com/dotnet/fsharp/pull/17485))
 
 ### Changed
@@ -27,4 +27,5 @@
 * Enforce `AttributeTargets` on unions. ([PR #17389](https://github.com/dotnet/fsharp/pull/17389))
 * Ensure that isinteractive multi-emit backing fields are not public. ([Issue #17439](https://github.com/dotnet/fsharp/issues/17438)), ([PR #17439](https://github.com/dotnet/fsharp/pull/17439))
 * Enable FSharp 9.0 Language Version ([Issue #17497](https://github.com/dotnet/fsharp/issues/17438)), [PR](https://github.com/dotnet/fsharp/pull/17500)))
+* Better error reporting for unions with duplicated fields. ([PR #17521](https://github.com/dotnet/fsharp/pull/17521))
 ### Breaking Changes

docs/release-notes/.Language/preview.md

@@ -7,7 +7,7 @@
 * Bidirectional F#/C# interop for 'unmanaged' constraint. ([PR #12154](https://github.com/dotnet/fsharp/pull/12154))
 * Make `.Is*` discriminated union properties visible. ([Language suggestion #222](https://github.com/fsharp/fslang-suggestions/issues/222), [PR #16341](https://github.com/dotnet/fsharp/pull/16341))
 * Allow returning bool instead of unit option for partial active patterns. ([Language suggestion #1041](https://github.com/fsharp/fslang-suggestions/issues/1041), [PR #16473](https://github.com/dotnet/fsharp/pull/16473))
-* Allow access modifies to auto properties getters and setters ([PR 16687](https://github.com/dotnet/fsharp/pull/16687), [PR 16861](https://github.com/dotnet/fsharp/pull/16861), [Language suggestion #430](https://github.com/fsharp/fslang-suggestions/issues/430))
+* Allow access modifies to auto properties getters and setters ([Language suggestion #430](https://github.com/fsharp/fslang-suggestions/issues/430), [PR 16687](https://github.com/dotnet/fsharp/pull/16687), [PR 16861](https://github.com/dotnet/fsharp/pull/16861), [PR 17522](https://github.com/dotnet/fsharp/pull/17522))
 * Allow #nowarn to support the FS prefix on error codes to disable warnings ([Issue #17206](https://github.com/dotnet/fsharp/issues/16447), [PR #17209](https://github.com/dotnet/fsharp/pull/17209))
 * Allow ParsedHashDirectives to have argument types other than strings ([Issue #17240](https://github.com/dotnet/fsharp/issues/16447), [PR #17209](https://github.com/dotnet/fsharp/pull/17209))
 * Support empty-bodied computation expressions. ([Language suggestion #1232](https://github.com/fsharp/fslang-suggestions/issues/1232), [PR #17352](https://github.com/dotnet/fsharp/pull/17352))

src/Compiler/Checking/CheckDeclarations.fs

@@ -500,18 +500,26 @@ module TcRecdUnionAndEnumDeclarations =
             if not (String.isLeadingIdentifierCharacterUpperCase name) && name <> opNameCons && name <> opNameNil then
                 errorR(NotUpperCaseConstructor(id.idRange))
 
-    let ValidateFieldNames (synFields: SynField list, tastFields: RecdField list) = 
+    let private CheckUnionDuplicateFields (elems: Ident list) =
+        elems |> List.iteri (fun i (uc1: Ident) -> 
+            elems |> List.iteri (fun j (uc2: Ident) -> 
+                if j > i && uc1.idText = uc2.idText then 
+                   errorR(Error(FSComp.SR.tcFieldNameIsUsedModeThanOnce(uc1.idText), uc1.idRange))))
+
+    let ValidateFieldNames (synFields: SynField list, tastFields: RecdField list) =
+        let fields = synFields |> List.choose (function SynField(idOpt = Some ident) -> Some ident | _ -> None)
+        if fields.Length > 1 then
+            CheckUnionDuplicateFields fields
+
         let seen = Dictionary()
         (synFields, tastFields) ||> List.iter2 (fun sf f ->
             match seen.TryGetValue f.LogicalName with
             | true, synField ->
                 match sf, synField with
-                | SynField(idOpt = Some id), SynField(idOpt = Some _) ->
-                    error(Error(FSComp.SR.tcFieldNameIsUsedModeThanOnce(id.idText), id.idRange))
                 | SynField(idOpt = Some id), SynField(idOpt = None)
                 | SynField(idOpt = None), SynField(idOpt = Some id) ->
-                    error(Error(FSComp.SR.tcFieldNameConflictsWithGeneratedNameForAnonymousField(id.idText), id.idRange))
-                | _ -> assert false
+                    errorR(Error(FSComp.SR.tcFieldNameConflictsWithGeneratedNameForAnonymousField(id.idText), id.idRange))
+                | _ -> ()
             | _ ->
                 seen.Add(f.LogicalName, sf))
 

src/Compiler/FSComp.txt

@@ -1771,10 +1771,10 @@ featureReuseSameFieldsInStructUnions,"Share underlying fields in a [<Struct>] di
 3868,tcActivePatternArgsCountNotMatchOnlyPat,"This active pattern expects exactly one pattern argument, e.g., '%s pat'."
 3868,tcActivePatternArgsCountNotMatchArgs,"This active pattern expects %d expression argument(s), e.g., '%s%s'."
 3868,tcActivePatternArgsCountNotMatchArgsAndPat,"This active pattern expects %d expression argument(s) and a pattern argument, e.g., '%s%s pat'."
-featureAllowAccessModifiersToAutoPropertiesGettersAndSetters,"Allow access modifiers to auto properties getters and setters"
-3869,tcAccessModifiersNotAllowedInSRTPConstraint,"Access modifiers cannot be applied to an SRTP constraint."
 featureParsedHashDirectiveArgumentNonString,"# directives with non-quoted string arguments"
-3870,featureParsedHashDirectiveUnexpectedInteger,"Unexpected integer literal '%d'."
-3870,featureParsedHashDirectiveUnexpectedIdentifier,"Unexpected identifier '%s'."
+3869,featureParsedHashDirectiveUnexpectedInteger,"Unexpected integer literal '%d'."
+3869,featureParsedHashDirectiveUnexpectedIdentifier,"Unexpected identifier '%s'."
 featureEmptyBodiedComputationExpressions,"Support for computation expressions with empty bodies: builder {{ }}"
 3870,parsExpectingUnionCaseField,"Expecting union case field"
+featureAllowAccessModifiersToAutoPropertiesGettersAndSetters,"Allow access modifiers to auto properties getters and setters"
+3871,tcAccessModifiersNotAllowedInSRTPConstraint,"Access modifiers cannot be applied to an SRTP constraint."

src/Compiler/SyntaxTree/SyntaxTree.fsi

@@ -1489,7 +1489,7 @@ type SynComponentInfo =
     /// Gets the syntax range of this construct
     member Range: range
 
-/// Represents two access
+/// Represents one or two access modifier(s) in a property signature
 [<NoEquality; NoComparison; RequireQualifiedAccess>]
 type SynValSigAccess =
     | Single of accessibility: SynAccess option

src/FSharp.Core/option.fs

@@ -148,7 +148,7 @@ module Option =
     [<CompiledName("OfNullable")>]
     let inline ofNullable (value: System.Nullable<'T>) =
         if value.HasValue then
-            Some value.Value
+            Some (value.GetValueOrDefault())
         else
             None
 
@@ -338,7 +338,7 @@ module ValueOption =
     [<CompiledName("OfNullable")>]
     let inline ofNullable (value: System.Nullable<'T>) =
         if value.HasValue then
-            ValueSome value.Value
+            ValueSome (value.GetValueOrDefault())
         else
             ValueNone
 

tests/FSharp.Compiler.ComponentTests/Conformance/BasicGrammarElements/ExceptionDefinitions/E_ExnFieldConflictingName.fs

@@ -5,4 +5,6 @@
 
 exception AAA of Data1 : int * string
 
-exception BBB of A : int * A : string
+exception BBB of A : int * A : string
+
+exception CCC of A : int * A : string * A : int

tests/FSharp.Compiler.ComponentTests/Conformance/BasicGrammarElements/ExceptionDefinitions/ExceptionDefinitions.fs

@@ -226,8 +226,10 @@ module ExceptionDefinition =
         |> compile
         |> shouldFail
         |> withDiagnostics [
-            (Error 3176, Line 6, Col 18, Line 6, Col 23, "Named field 'Data1' conflicts with autogenerated name for anonymous field.")
-            (Error 3176, Line 8, Col 28, Line 8, Col 29, "Named field 'A' is used more than once.")
+            (Error 3176, Line 6, Col 18, Line 6, Col 23, "Named field 'Data1' conflicts with autogenerated name for anonymous field.");
+            (Error 3176, Line 8, Col 18, Line 8, Col 19, "Named field 'A' is used more than once.");
+            (Error 3176, Line 10, Col 18, Line 10, Col 19, "Named field 'A' is used more than once.");
+            (Error 3176, Line 10, Col 28, Line 10, Col 29, "Named field 'A' is used more than once.")
         ]
 
     // SOURCE=E_FieldNameUsedMulti.fs                      SCFLAGS="--test:ErrorRanges"        # E_FieldNameUsedMulti.fs

tests/FSharp.Compiler.ComponentTests/Conformance/Types/TypeConstraints/IWSAMsAndSRTPs/IWSAMsAndSRTPsTests.fs

@@ -1282,10 +1282,10 @@ let inline length4 (x: ^a when ^a: (member public get_Length: unit -> int)) = x.
         |> typecheck
         |> shouldFail
         |> withDiagnostics [
-            (Error 3869, Line 2, Col 43, Line 2, Col 49, "Access modifiers cannot be applied to an SRTP constraint.")
-            (Error 3869, Line 3, Col 61, Line 3, Col 67, "Access modifiers cannot be applied to an SRTP constraint.")
-            (Error 3869, Line 4, Col 61, Line 4, Col 67, "Access modifiers cannot be applied to an SRTP constraint.")
-            (Error 3869, Line 5, Col 44, Line 5, Col 50, "Access modifiers cannot be applied to an SRTP constraint.")
+            (Error 3871, Line 2, Col 43, Line 2, Col 49, "Access modifiers cannot be applied to an SRTP constraint.")
+            (Error 3871, Line 3, Col 61, Line 3, Col 67, "Access modifiers cannot be applied to an SRTP constraint.")
+            (Error 3871, Line 4, Col 61, Line 4, Col 67, "Access modifiers cannot be applied to an SRTP constraint.")
+            (Error 3871, Line 5, Col 44, Line 5, Col 50, "Access modifiers cannot be applied to an SRTP constraint.")
         ]
 
     [<Fact>]
@@ -1300,10 +1300,10 @@ let inline length4 (x: ^a when ^a: (member public get_Length: unit -> int)) = x.
         |> typecheck
         |> shouldFail
         |> withDiagnostics [
-            (Warning 3869, Line 2, Col 43, Line 2, Col 49, "Access modifiers cannot be applied to an SRTP constraint.")
-            (Warning 3869, Line 3, Col 61, Line 3, Col 67, "Access modifiers cannot be applied to an SRTP constraint.")
-            (Warning 3869, Line 4, Col 61, Line 4, Col 67, "Access modifiers cannot be applied to an SRTP constraint.")
-            (Warning 3869, Line 5, Col 44, Line 5, Col 50, "Access modifiers cannot be applied to an SRTP constraint.")
+            (Warning 3871, Line 2, Col 43, Line 2, Col 49, "Access modifiers cannot be applied to an SRTP constraint.")
+            (Warning 3871, Line 3, Col 61, Line 3, Col 67, "Access modifiers cannot be applied to an SRTP constraint.")
+            (Warning 3871, Line 4, Col 61, Line 4, Col 67, "Access modifiers cannot be applied to an SRTP constraint.")
+            (Warning 3871, Line 5, Col 44, Line 5, Col 50, "Access modifiers cannot be applied to an SRTP constraint.")
         ]
 
     [<FactForNETCOREAPP>]

tests/FSharp.Compiler.ComponentTests/Conformance/Types/UnionTypes/E_UnionFieldConflictingName.fs

@@ -7,4 +7,4 @@ type MyDU =
     | Case1 of Item2 : int * string
 
 type MyDU2 = 
-    | Case1 of A : int * A : string
+    | Case1 of A : int * A : string * A : int

tests/FSharp.Compiler.ComponentTests/Conformance/Types/UnionTypes/UnionStructTypes.fs

@@ -402,7 +402,9 @@ type StructUnion =
         |> typecheck
         |> shouldFail
         |> withDiagnostics [
-            (Error 3176, Line 5, Col 27, Line 5, Col 31, "Named field 'item' is used more than once.")
+            (Error 3176, Line 5, Col 12, Line 5, Col 16, "Named field 'item' is used more than once.");
+            (Error 3585, Line 5, Col 12, Line 5, Col 16, "If a multicase union type is a struct, then all fields with the same name must be of the same type. This rule applies also to the generated 'Item' name in case of unnamed fields.");
+            (Error 3585, Line 5, Col 27, Line 5, Col 31, "If a multicase union type is a struct, then all fields with the same name must be of the same type. This rule applies also to the generated 'Item' name in case of unnamed fields.")
         ]
 
     [<Fact>]
@@ -417,7 +419,10 @@ type StructUnion =
         |> typecheck
         |> shouldFail
         |> withDiagnostics [
-            (Error 3176, Line 5, Col 27, Line 5, Col 31, "Named field 'Item' is used more than once.")
+            (Error 3176, Line 5, Col 12, Line 5, Col 16, "Named field 'Item' is used more than once.");
+            (Error 3585, Line 5, Col 12, Line 5, Col 16, "If a multicase union type is a struct, then all fields with the same name must be of the same type. This rule applies also to the generated 'Item' name in case of unnamed fields.");
+            (Error 3585, Line 5, Col 27, Line 5, Col 31, "If a multicase union type is a struct, then all fields with the same name must be of the same type. This rule applies also to the generated 'Item' name in case of unnamed fields.");
+            (Error 3585, Line 6, Col 12, Line 6, Col 18, "If a multicase union type is a struct, then all fields with the same name must be of the same type. This rule applies also to the generated 'Item' name in case of unnamed fields.")
         ]
 
     [<Fact>]

tests/FSharp.Compiler.ComponentTests/Conformance/Types/UnionTypes/UnionTypes.fs

@@ -272,7 +272,8 @@ module UnionTypes =
         |> verifyCompile
         |> shouldFail
         |> withDiagnostics [
-            (Error 3176, Line 7, Col 16, Line 7, Col 21, "Named field 'Item2' conflicts with autogenerated name for anonymous field.")
+            (Error 3176, Line 7, Col 16, Line 7, Col 21, "Named field 'Item2' conflicts with autogenerated name for anonymous field.");
+            (Error 3176, Line 10, Col 16, Line 10, Col 17, "Named field 'A' is used more than once.");
             (Error 3176, Line 10, Col 26, Line 10, Col 27, "Named field 'A' is used more than once.")
         ]
 
@@ -750,3 +751,59 @@ type MyId =
             (Error 23, Line 7, Col 17, Line 7, Col 20, "The member 'IdA' can not be defined because the name 'IdA' clashes with the union case 'IdA' in this type or module")
             (Error 23, Line 17, Col 17, Line 17, Col 20, "The member 'IdC' can not be defined because the name 'IdC' clashes with the union case 'IdC' in this type or module")
         ]
+
+
+    [<Fact>]
+    let ``Union field appears multiple times in union declaration`` () =
+        Fsx """
+type X =
+    | A of a: int * a: int
+        """
+        |> typecheck
+        |> shouldFail
+        |> withDiagnostics [
+            (Error 3176, Line 3, Col 12, Line 3, Col 13, "Named field 'a' is used more than once.")
+        ]
+
+    [<Fact>]
+    let ``Union field appears multiple times in union declaration 2`` () =
+        Fsx """
+type X =
+    | A of a: int * a: int
+    | B of a: int * a: int
+        """
+        |> typecheck
+        |> shouldFail
+        |> withDiagnostics [
+            (Error 3176, Line 3, Col 12, Line 3, Col 13, "Named field 'a' is used more than once.")
+            (Error 3176, Line 4, Col 12, Line 4, Col 13, "Named field 'a' is used more than once.")
+        ]
+
+    [<Fact>]
+    let ``Union field appears multiple times in union declaration 3`` () =
+        Fsx """
+type X =
+    | A of a: int * a: int * a: int
+        """
+        |> typecheck
+        |> shouldFail
+        |> withDiagnostics [
+            (Error 3176, Line 3, Col 12, Line 3, Col 13, "Named field 'a' is used more than once.")
+            (Error 3176, Line 3, Col 21, Line 3, Col 22, "Named field 'a' is used more than once.")
+        ]
+
+    [<Fact>]
+    let ``Union field appears multiple times in union declaration 4`` () =
+        Fsx """
+type X =
+    | A of a: int * a: int
+let x = A (1, 2)
+match x with
+| A(a = 1) -> ()
+| _ -> ()
+        """
+        |> typecheck
+        |> shouldFail
+        |> withDiagnostics [
+            (Error 3176, Line 3, Col 12, Line 3, Col 13, "Named field 'a' is used more than once.")
+        ]

tests/FSharp.Compiler.ComponentTests/ErrorMessages/Directives.fs

@@ -275,10 +275,10 @@ printfn "Hello, World"
         |> asExe
         |> compile
         |> shouldFail
-        |> withDiagnostics[
+        |> withDiagnostics [
             (Warning 3353, Line 2, Col 9, Line 2, Col 11, "Invalid directive '#r '")
             (Warning 213, Line 3, Col 9, Line 3, Col 14, "'' is not a valid assembly name")
-            (Error 3870, Line 4, Col 12, Line 4, Col 17, "Unexpected identifier 'Ident'.")
-            (Error 3870, Line 5, Col 12, Line 5, Col 22, "Unexpected identifier 'Long.Ident'.")
-            (Error 3870, Line 6, Col 12, Line 6, Col 15, "Unexpected integer literal '123'.")
-            ]
+            (Error 3869, Line 4, Col 12, Line 4, Col 17, "Unexpected identifier 'Ident'.")
+            (Error 3869, Line 5, Col 12, Line 5, Col 22, "Unexpected identifier 'Long.Ident'.")
+            (Error 3869, Line 6, Col 12, Line 6, Col 15, "Unexpected integer literal '123'.")
+        ]