Error for primary constructor in delegate definition (#13078)

Co-authored-by: Vlad Zarytovskii <[email protected]>

Author: edgarfgp

DEVGUIDE.md

@@ -128,8 +128,11 @@ If your changes involve modifying the list of language keywords in any way, (e.g
 ```shell
 dotnet build src\Compiler /t:UpdateXlf
 ```
+If you are on a Mac, you can run this command from the root of the repository:
 
-This only works on Windows/.NETStandard framework, so changing this from any other platform requires editing and syncing all of the XLF files manually.
+```shell
+sh build.sh -c Release
+```
 
 ## Updating baselines in tests
 

src/Compiler/Checking/CheckDeclarations.fs

@@ -3985,7 +3985,13 @@ module EstablishTypeDefinitionCores =
                 match fields' with 
                 | rf :: _ -> errorR (Error(FSComp.SR.tcInterfaceTypesAndDelegatesCannotContainFields(), rf.Range))
                 | _ -> ()
-
+            
+            let primaryConstructorInDelegateCheck(implicitCtorSynPats : SynSimplePats option) =
+                match implicitCtorSynPats with 
+                | None -> ()
+                | Some spats ->
+                    let ctorArgNames, _ = TcSimplePatsOfUnknownType cenv true CheckCxs envinner tpenv spats
+                    if not ctorArgNames.IsEmpty then errorR (Error(FSComp.SR.parsOnlyClassCanTakeValueArguments(), m))
 
             let envinner = AddDeclaredTypars CheckForDuplicateTypars (tycon.Typars m) envinner
             let envinner = MakeInnerEnvForTyconRef envinner thisTyconRef false 
@@ -4182,6 +4188,7 @@ module EstablishTypeDefinitionCores =
                                   noAllowNullLiteralAttributeCheck()
                                   noAbstractClassAttributeCheck()
                                   noFieldsCheck userFields
+                                  primaryConstructorInDelegateCheck(implicitCtorSynPats)
                                   let tyR, _ = TcTypeAndRecover cenv NoNewTypars CheckCxs ItemOccurence.UseInType envinner tpenv ty
                                   let _, _, curriedArgInfos, returnTy, _ = GetTopValTypeInCompiledForm g (arity |> TranslateSynValInfo m (TcAttributes cenv envinner)  |> TranslatePartialValReprInfo []) 0 tyR m
                                   if curriedArgInfos.Length < 1 then error(Error(FSComp.SR.tcInvalidDelegateSpecification(), m))

tests/FSharp.Compiler.ComponentTests/Conformance/DelegateTypes/DelegateDefinition.fs

@@ -0,0 +1,45 @@
+// Copyright (c) Microsoft Corporation.  All Rights Reserved.  See License.txt in the project root for license information.
+
+namespace FSharp.Compiler.ComponentTests.Conformance.DelegateTypes
+
+open Xunit
+open FSharp.Test.Compiler
+
+module DelegateDefinition =
+
+    [<Fact>]
+    let ``Delegate definition with primary constructor and argument.`` () =
+        FSharp
+            """
+namespace FSharpTest
+    type T(x: int) =
+        delegate of int -> int
+        """
+        |> compile
+        |> shouldFail
+        |> withErrorCode 552
+        |> withErrorMessage "Only class types may take value arguments"
+        
+    [<Fact>]
+    let ``Delegate definition with primary constructor no argument.`` () =
+        FSharp
+            """
+namespace FSharpTest
+    type T() =
+        delegate of int -> int
+        """
+        |> compile
+        |> shouldFail
+        |> withErrorCode 552
+        |> withErrorMessage "Only class types may take value arguments"
+
+    [<Fact>]
+    let ``Delegate definition`` () =
+        FSharp
+            """
+namespace FSharpTest
+    type T =
+        delegate of int -> int
+        """
+        |> compile
+        |> shouldSucceed

tests/FSharp.Compiler.ComponentTests/Conformance/DelegateTypes/invalid_delegate_definition.fs

@@ -0,0 +1,5 @@
+type T(x: int) =
+    delegate of int -> int
+
+type T() =
+    delegate of int -> int

tests/FSharp.Compiler.ComponentTests/Conformance/DelegateTypes/invalid_delegate_definition.fs.err.bsl

@@ -0,0 +1,3 @@
+invalid_delegate_definition.fs (1,6)-(1,15) Only class types may take value arguments
+invalid_delegate_definition.fs (4,6)-(1,9) Only class types may take value arguments
+

tests/FSharp.Compiler.ComponentTests/FSharp.Compiler.ComponentTests.fsproj

@@ -32,6 +32,7 @@
     <Compile Include="Conformance\ClassTypes\ExplicitObjectConstructors\ExplicitObjectConstructors.fs" />
     <Compile Include="Conformance\ClassTypes\ImplicitObjectConstructors\ImplicitObjectConstructors.fs" />
     <Compile Include="Conformance\ClassTypes\ValueRestriction\ValueRestriction.fs" />
+	<Compile Include="Conformance\DelegateTypes\DelegateDefinition.fs" />
     <Compile Include="Conformance\DeclarationElements\AccessibilityAnnotations\Basic\Basic.fs" />
     <Compile Include="Conformance\DeclarationElements\AccessibilityAnnotations\OnOverridesAndIFaceImpl\OnOverridesAndIFaceImpl.fs" />
     <Compile Include="Conformance\DeclarationElements\AccessibilityAnnotations\OnTypeMembers\OnTypeMembers.fs" />

tests/fsharp/typecheck/sigs/neg06.fs

@@ -24,7 +24,7 @@ type BadSealedInterface =
 type BadSealedAbbreviatedType = System.Object 
 
 [<Sealed>]
-type UnnecessarilySealedDelegate() = delegate of int -> int
+type UnnecessarilySealedDelegate = delegate of int -> int
 
 type BadExtensionOfSealedType() = 
     class

tests/fsharpqa/Source/Conformance/ObjectOrientedTypeDefinitions/DelegateTypes/env.lst

@@ -1,10 +1,9 @@
 	SOURCE=ByrefArguments01.fs			# ByrefArguments01.fs
 	SOURCE=E_InvalidSignature01.fs			# E_InvalidSignature01.fs
 	SOURCE=E_InvalidSignature02.fs			# E_InvalidSignature02.fs
-
 	SOURCE=ValidSignature_MultiArg01.fs		# ValidSignature_MultiArg01.fs
 	SOURCE=ValidSignature_ReturningValues01.fs	# ValidSignature_ReturningValues01.fs
 
 # This test has a dependency on NetFx3.5 (i.e. CSC_PIPE must be 3.5 or better)
 # For this reason, we exclude it from MT
-NoMT		SOURCE=DelegateBindingInvoke01.fs    PRECMD="\$CSC_PIPE /t:library IDelegateBinding.cs"    SCFLAGS="-r:IDelegateBinding.dll"	# DelegateBindingInvoke01.fs 
+NoMT		SOURCE=DelegateBindingInvoke01.fs    PRECMD="\$CSC_PIPE /t:library IDelegateBinding.cs"    SCFLAGS="-r:IDelegateBinding.dll"	# DelegateBindingInvoke01.fs