Better error range for `struct` and restricted super types `inherit` (#17886)

* Better error range for struct inherit * CheckSuperType * release notes * E_RestrictedSuperTypes * neg6.bsl * neg4.bsl
2024-10-16 13:39:58 +01:00 · 2024-10-16 13:39:58 +01:00 · 346a59f93e
--- a/docs/release-notes/.FSharp.Compiler.Service/9.0.200.md
+++ b/docs/release-notes/.FSharp.Compiler.Service/9.0.200.md
@ -21,5 +21,6 @@
 * Better ranges for CE `match!`. ([PR #17789](https://github.com/dotnet/fsharp/pull/17789))
 * Better ranges for CE `use` error reporting. ([PR #17811](https://github.com/dotnet/fsharp/pull/17811))
 * Better ranges for `inherit` error reporting. ([PR #17879](https://github.com/dotnet/fsharp/pull/17879))
+* Better ranges for `inherit` `struct` error reporting. ([PR #17886](https://github.com/dotnet/fsharp/pull/17886))

 ### Breaking Changes
--- a/src/Compiler/Checking/CheckDeclarations.fs
+++ b/src/Compiler/Checking/CheckDeclarations.fs
@ -3322,7 +3322,7 @@ module EstablishTypeDefinitionCores =
                  | SynTypeDefnSimpleRepr.Record _ ->
                      if tycon.IsStructRecordOrUnionTycon then Some(g.system_Value_ty)
                      else None
-                  | SynTypeDefnSimpleRepr.General (kind, _, slotsigs, fields, isConcrete, _, _, _) ->
+                  | SynTypeDefnSimpleRepr.General (kind, inherits, slotsigs, fields, isConcrete, _, _, _) ->
                      let kind = InferTyconKind g (kind, attrs, slotsigs, fields, inSig, isConcrete, m)
                                           
                      match inheritedTys with 
@ -3333,15 +3333,20 @@ module EstablishTypeDefinitionCores =
                          | SynTypeDefnKind.Opaque | SynTypeDefnKind.Class | SynTypeDefnKind.Interface -> None
                          | _ -> error(InternalError("should have inferred tycon kind", m)) 

-                      | [(ty, m)] -> 
-                          if not firstPass && not (match kind with SynTypeDefnKind.Class -> true | _ -> false) then 
-                              errorR (Error(FSComp.SR.tcStructsInterfacesEnumsDelegatesMayNotInheritFromOtherTypes(), m)) 
-                          CheckSuperType cenv ty m 
+                      | [(ty, m)] ->
+                          let inheritRange =
+                                match inherits with
+                                | [] -> m
+                                | (synType, _, _) :: _ -> synType.Range
+                          if not firstPass && not (match kind with SynTypeDefnKind.Class -> true | _ -> false) then
+                              errorR (Error(FSComp.SR.tcStructsInterfacesEnumsDelegatesMayNotInheritFromOtherTypes(), inheritRange)) 
+                          CheckSuperType cenv ty inheritRange 
                          if isTyparTy g ty then 
                              if firstPass then 
-                                  errorR(Error(FSComp.SR.tcCannotInheritFromVariableType(), m)) 
+                                  errorR(Error(FSComp.SR.tcCannotInheritFromVariableType(), inheritRange)) 
                              Some g.obj_ty_noNulls // a "super" that is a variable type causes grief later
-                          else                          
+                          else             
+                                       
                              Some ty 
                      | _ -> 
                          error(Error(FSComp.SR.tcTypesCannotInheritFromMultipleConcreteTypes(), m))
--- a/src/Compiler/Checking/Expressions/CheckExpressions.fs
+++ b/src/Compiler/Checking/Expressions/CheckExpressions.fs
@ -7140,7 +7140,7 @@ and CheckSuperType (cenv: cenv) ty m =
       typeEquiv g ty g.system_Array_ty ||
       typeEquiv g ty g.system_MulticastDelegate_ty ||
       typeEquiv g ty g.system_Delegate_ty then
-         error(Error(FSComp.SR.tcPredefinedTypeCannotBeUsedAsSuperType(), m))
+         errorR(Error(FSComp.SR.tcPredefinedTypeCannotBeUsedAsSuperType(), m))

    if isErasedType g ty then
        errorR(Error(FSComp.SR.tcCannotInheritFromErasedType(), m))
--- a/tests/FSharp.Compiler.ComponentTests/Conformance/Types/StructTypes/E_Inheritance.fs
+++ b/tests/FSharp.Compiler.ComponentTests/Conformance/Types/StructTypes/E_Inheritance.fs
@ -0,0 +1,7 @@
+type TK_I_005 =
+  abstract M  : unit -> unit
+  
+[<Struct>]
+type TK_I_006b = 
+   inherit TK_I_005
+  
--- a/tests/FSharp.Compiler.ComponentTests/Conformance/Types/StructTypes/StructTypes.fs
+++ b/tests/FSharp.Compiler.ComponentTests/Conformance/Types/StructTypes/StructTypes.fs
@ -38,3 +38,15 @@ module StructTypes =
        |> shouldSucceed
        |> ignore

+    [<Theory; Directory(__SOURCE_DIRECTORY__, Includes=[|"E_Inheritance.fs"|])>]
+    let ``StructTypes - E_Inheritance.fs`` compilation =
+        compilation
+        |> asFsx
+        |> withOptions ["--warnaserror+"; "--nowarn:988"]
+        |> typecheck
+        |> shouldFail
+        |> withDiagnostics [
+            (Error 931, Line 6, Col 12, Line 6, Col 20, "Structs, interfaces, enums and delegates cannot inherit from other types");
+            (Error 946, Line 6, Col 12, Line 6, Col 20, "Cannot inherit from interface type. Use interface ... with instead.")
+        ]
+
--- a/tests/FSharp.Compiler.ComponentTests/ErrorMessages/ClassesTests.fs
+++ b/tests/FSharp.Compiler.ComponentTests/ErrorMessages/ClassesTests.fs
@ -830,4 +830,23 @@ type Class() =
        |> withDiagnostics [
            (Error 961, Line 5, Col 5, Line 5, Col 12, "This 'inherit' declaration specifies the inherited type but no arguments. Consider supplying arguments, e.g. 'inherit BaseType(args)'.")
            (Error 946, Line 5, Col 13, Line 5, Col 15, "Cannot inherit from interface type. Use interface ... with instead.")
+        ]
+
+    [<Fact>]
+    let ``The types System.ValueType, System.Enum, System.Delegate, System.MulticastDelegate and System.Array cannot be used as super types in an object expression or class.`` () =
+        Fsx """
+type C1 = class inherit System.ValueType override x.ToString() = ""  end
+type C2 = class inherit System.Array override x.ToString() = ""  end
+type C3 = class inherit System.Enum override x.ToString() = ""  end
+type C4 = class inherit System.Delegate override x.ToString() = ""  end
+type C5 = class inherit System.MulticastDelegate override x.ToString() = ""  end
+        """
+        |> typecheck
+        |> shouldFail
+        |> withDiagnostics [
+            (Error 771, Line 2, Col 25, Line 2, Col 41, "The types System.ValueType, System.Enum, System.Delegate, System.MulticastDelegate and System.Array cannot be used as super types in an object expression or class");
+            (Error 771, Line 3, Col 25, Line 3, Col 37, "The types System.ValueType, System.Enum, System.Delegate, System.MulticastDelegate and System.Array cannot be used as super types in an object expression or class");
+            (Error 771, Line 4, Col 25, Line 4, Col 36, "The types System.ValueType, System.Enum, System.Delegate, System.MulticastDelegate and System.Array cannot be used as super types in an object expression or class")
+            (Error 771, Line 5, Col 25, Line 5, Col 40, "The types System.ValueType, System.Enum, System.Delegate, System.MulticastDelegate and System.Array cannot be used as super types in an object expression or class");
+            (Error 771, Line 6, Col 25, Line 6, Col 49, "The types System.ValueType, System.Enum, System.Delegate, System.MulticastDelegate and System.Array cannot be used as super types in an object expression or class")
        ]
--- a/tests/fsharp/typeProviders/negTests/neg4.bsl
+++ b/tests/fsharp/typeProviders/negTests/neg4.bsl
@ -17,12 +17,12 @@ neg4.fsx(30,5,30,22): typecheck error FS3062: This type test with a provided typ

 neg4.fsx(36,5,36,28): typecheck error FS3060: This type test or downcast will erase the provided type 'HelloWorldType' to the type 'System.Object'

-neg4.fsx(42,8,42,33): typecheck error FS3063: Cannot inherit from erased provided type
+neg4.fsx(42,16,42,33): typecheck error FS3063: Cannot inherit from erased provided type

-neg4.fsx(42,8,42,33): typecheck error FS3063: Cannot inherit from erased provided type
+neg4.fsx(42,16,42,33): typecheck error FS3063: Cannot inherit from erased provided type

-neg4.fsx(47,8,47,35): typecheck error FS3063: Cannot inherit from erased provided type
+neg4.fsx(47,16,47,33): typecheck error FS3063: Cannot inherit from erased provided type

-neg4.fsx(47,8,47,35): typecheck error FS3063: Cannot inherit from erased provided type
+neg4.fsx(47,16,47,33): typecheck error FS3063: Cannot inherit from erased provided type

 neg4.fsx(52,25,52,42): typecheck error FS3063: Cannot inherit from erased provided type
--- a/tests/fsharp/typeProviders/negTests/neg6.bsl
+++ b/tests/fsharp/typeProviders/negTests/neg6.bsl
@ -1,12 +1,12 @@

-neg6.fsx(8,3,8,27): typecheck error FS3063: Cannot inherit from erased provided type
+neg6.fsx(8,11,8,25): typecheck error FS3063: Cannot inherit from erased provided type

-neg6.fsx(8,3,8,27): typecheck error FS3063: Cannot inherit from erased provided type
+neg6.fsx(8,11,8,25): typecheck error FS3063: Cannot inherit from erased provided type

-neg6.fsx(11,3,11,30): typecheck error FS3063: Cannot inherit from erased provided type
+neg6.fsx(11,11,11,28): typecheck error FS3063: Cannot inherit from erased provided type

-neg6.fsx(11,3,11,30): typecheck error FS3063: Cannot inherit from erased provided type
+neg6.fsx(11,11,11,28): typecheck error FS3063: Cannot inherit from erased provided type

-neg6.fsx(14,3,14,35): typecheck error FS3063: Cannot inherit from erased provided type
+neg6.fsx(14,11,14,33): typecheck error FS3063: Cannot inherit from erased provided type

-neg6.fsx(14,3,14,35): typecheck error FS3063: Cannot inherit from erased provided type
+neg6.fsx(14,11,14,33): typecheck error FS3063: Cannot inherit from erased provided type
--- a/tests/fsharpqa/Source/Conformance/ObjectOrientedTypeDefinitions/ClassTypes/Misc/E_RestrictedSuperTypes.fs
+++ b/tests/fsharpqa/Source/Conformance/ObjectOrientedTypeDefinitions/ClassTypes/Misc/E_RestrictedSuperTypes.fs
@ -5,16 +5,16 @@
 //<Expects id="FS0771" span="(22,16)" status="error">The types System\.ValueType, System\.Enum, System\.Delegate, System\.MulticastDelegate and System\.Array cannot be used as super types in an object expression or class</Expects>
 //<Expects id="FS0771" span="(23,16)" status="error">The types System\.ValueType, System\.Enum, System\.Delegate, System\.MulticastDelegate and System\.Array cannot be used as super types in an object expression or class</Expects>
 //<Expects id="FS0771" span="(24,16)" status="error">The types System\.ValueType, System\.Enum, System\.Delegate, System\.MulticastDelegate and System\.Array cannot be used as super types in an object expression or class</Expects>
-//<Expects id="FS0771" span="(26,17)" status="error">The types System\.ValueType, System\.Enum, System\.Delegate, System\.MulticastDelegate and System\.Array cannot be used as super types in an object expression or class</Expects>
-//<Expects id="FS0771" span="(26,17)" status="error">The types System\.ValueType, System\.Enum, System\.Delegate, System\.MulticastDelegate and System\.Array cannot be used as super types in an object expression or class</Expects>
-//<Expects id="FS0771" span="(27,17)" status="error">The types System\.ValueType, System\.Enum, System\.Delegate, System\.MulticastDelegate and System\.Array cannot be used as super types in an object expression or class</Expects>
-//<Expects id="FS0771" span="(27,17)" status="error">The types System\.ValueType, System\.Enum, System\.Delegate, System\.MulticastDelegate and System\.Array cannot be used as super types in an object expression or class</Expects>
-//<Expects id="FS0771" span="(28,17)" status="error">The types System\.ValueType, System\.Enum, System\.Delegate, System\.MulticastDelegate and System\.Array cannot be used as super types in an object expression or class</Expects>
-//<Expects id="FS0771" span="(28,17)" status="error">The types System\.ValueType, System\.Enum, System\.Delegate, System\.MulticastDelegate and System\.Array cannot be used as super types in an object expression or class</Expects>
-//<Expects id="FS0771" span="(29,17)" status="error">The types System\.ValueType, System\.Enum, System\.Delegate, System\.MulticastDelegate and System\.Array cannot be used as super types in an object expression or class</Expects>
-//<Expects id="FS0771" span="(29,17)" status="error">The types System\.ValueType, System\.Enum, System\.Delegate, System\.MulticastDelegate and System\.Array cannot be used as super types in an object expression or class</Expects>
-//<Expects id="FS0771" span="(30,17)" status="error">The types System\.ValueType, System\.Enum, System\.Delegate, System\.MulticastDelegate and System\.Array cannot be used as super types in an object expression or class</Expects>
-//<Expects id="FS0771" span="(30,17)" status="error">The types System\.ValueType, System\.Enum, System\.Delegate, System\.MulticastDelegate and System\.Array cannot be used as super types in an object expression or class</Expects>
+//<Expects id="FS0771" span="(26,25)" status="error">The types System\.ValueType, System\.Enum, System\.Delegate, System\.MulticastDelegate and System\.Array cannot be used as super types in an object expression or class</Expects>
+//<Expects id="FS0771" span="(26,25)" status="error">The types System\.ValueType, System\.Enum, System\.Delegate, System\.MulticastDelegate and System\.Array cannot be used as super types in an object expression or class</Expects>
+//<Expects id="FS0771" span="(27,25)" status="error">The types System\.ValueType, System\.Enum, System\.Delegate, System\.MulticastDelegate and System\.Array cannot be used as super types in an object expression or class</Expects>
+//<Expects id="FS0771" span="(27,25)" status="error">The types System\.ValueType, System\.Enum, System\.Delegate, System\.MulticastDelegate and System\.Array cannot be used as super types in an object expression or class</Expects>
+//<Expects id="FS0771" span="(28,25)" status="error">The types System\.ValueType, System\.Enum, System\.Delegate, System\.MulticastDelegate and System\.Array cannot be used as super types in an object expression or class</Expects>
+//<Expects id="FS0771" span="(28,25)" status="error">The types System\.ValueType, System\.Enum, System\.Delegate, System\.MulticastDelegate and System\.Array cannot be used as super types in an object expression or class</Expects>
+//<Expects id="FS0771" span="(29,25)" status="error">The types System\.ValueType, System\.Enum, System\.Delegate, System\.MulticastDelegate and System\.Array cannot be used as super types in an object expression or class</Expects>
+//<Expects id="FS0771" span="(29,25)" status="error">The types System\.ValueType, System\.Enum, System\.Delegate, System\.MulticastDelegate and System\.Array cannot be used as super types in an object expression or class</Expects>
+//<Expects id="FS0771" span="(30,25)" status="error">The types System\.ValueType, System\.Enum, System\.Delegate, System\.MulticastDelegate and System\.Array cannot be used as super types in an object expression or class</Expects>
+//<Expects id="FS0771" span="(30,25)" status="error">The types System\.ValueType, System\.Enum, System\.Delegate, System\.MulticastDelegate and System\.Array cannot be used as super types in an object expression or class</Expects>

 #light
 let o1 = { new System.ValueType with member x.ToString() = "" }
--- a/tests/fsharpqa/Source/Conformance/ObjectOrientedTypeDefinitions/TypeKindInference/infer_interface002e.fs
+++ b/tests/fsharpqa/Source/Conformance/ObjectOrientedTypeDefinitions/TypeKindInference/infer_interface002e.fs
@ -1,10 +1,10 @@
 // #Regression #Conformance #ObjectOrientedTypes #TypeInference 
 // attribute must match inferred type
 //<Expects id="FS0927" span="(16,6-16,15)" status="error">The kind of the type specified by its attributes does not match the kind implied by its definition</Expects>
-//<Expects id="FS0931" span="(20,4-20,20)" status="error">Structs, interfaces, enums and delegates cannot inherit from other types</Expects>
+//<Expects id="FS0931" span="(20,12-20,20)" status="error">Structs, interfaces, enums and delegates cannot inherit from other types</Expects>
 //<Expects id="FS0946" span="(20,12-20,20)" status="error">Cannot inherit from interface type\. Use interface \.\.\. with instead</Expects>
 //<Expects id="FS0927" span="(28,6-28,15)" status="error">The kind of the type specified by its attributes does not match the kind implied by its definition</Expects>
-//<Expects id="FS0931" span="(32,4-32,20)" status="error">Structs, interfaces, enums and delegates cannot inherit from other types</Expects>
+//<Expects id="FS0931" span="(32,12-32,20)" status="error">Structs, interfaces, enums and delegates cannot inherit from other types</Expects>
 //<Expects id="FS0946" span="(32,12-32,20)" status="error">Cannot inherit from interface type\. Use interface \.\.\. with instead</Expects>

 // An interface