Improve error reporting for abstract members when used in classes

src/Compiler/Checking/CheckDeclarations.fs

@@ -54,6 +54,8 @@ type cenv = TcFileState
 type MutRecDataForOpen = MutRecDataForOpen of SynOpenDeclTarget * range * appliedScope: range * OpenDeclaration list ref
 type MutRecDataForModuleAbbrev = MutRecDataForModuleAbbrev of Ident * LongIdent * range
 
+exception TypeIsImplicitlyAbstract of range
+
 /// Represents the shape of a mutually recursive group of declarations including nested modules
 [<RequireQualifiedAccess>]
 type MutRecShape<'TypeData, 'LetsData, 'ModuleData> = 
@@ -3629,8 +3631,10 @@ module EstablishTypeDefinitionCores =
                                   noSealedAttributeCheck FSComp.SR.tcTypesAreAlwaysSealedStruct
                                   noAbstractClassAttributeCheck()
                                   noAllowNullLiteralAttributeCheck()
-                                  if not (isNil slotsigs) then 
-                                    errorR (Error(FSComp.SR.tcStructTypesCannotContainAbstractMembers(), m)) 
+
+                                  for slot in abstractSlots do
+                                    errorR (Error(FSComp.SR.tcStructTypesCannotContainAbstractMembers(), slot.Range))
+
                                   structLayoutAttributeCheck true
 
                                   TFSharpStruct
@@ -3647,8 +3651,11 @@ module EstablishTypeDefinitionCores =
                                   structLayoutAttributeCheck(not isIncrClass)
                                   allowNullLiteralAttributeCheck()
                                   for slot in abstractSlots do
-                                      if not slot.IsInstanceMember then
-                                          errorR(Error(FSComp.SR.chkStaticAbstractMembersOnClasses(), slot.Range))
+                                    if not slot.IsInstanceMember then
+                                        errorR(Error(FSComp.SR.chkStaticAbstractMembersOnClasses(), slot.Range))
+                                    elif not hasAbstractAttr then
+                                        errorR(TypeIsImplicitlyAbstract(slot.Range))
+
                                   TFSharpClass
                               | SynTypeDefnKind.Delegate (ty, arity) -> 
                                   noCLIMutableAttributeCheck()

src/Compiler/Checking/CheckDeclarations.fsi

@@ -79,3 +79,5 @@ val CheckOneSigFile:
 exception NotUpperCaseConstructor of range: range
 
 exception NotUpperCaseConstructorWithoutRQA of range: range
+
+exception TypeIsImplicitlyAbstract of range

src/Compiler/Checking/MethodOverrides.fs

@@ -103,7 +103,6 @@ type SlotImplSet =
         availablePriorOverrides: OverrideInfo list *
         requiredProperties: PropInfo list
 
-exception TypeIsImplicitlyAbstract of range
 exception OverrideDoesntOverride of DisplayEnv * OverrideInfo * MethInfo option * TcGlobals * Import.ImportMap * range
 
 module DispatchSlotChecking =
@@ -828,11 +827,7 @@ module DispatchSlotChecking =
 
                 if isImplementation && not (isInterfaceTy g overallTy) then 
                     let overrides = allImmediateMembersThatMightImplementDispatchSlots |> List.map snd
-                    let allCorrect = CheckDispatchSlotsAreImplemented (denv, infoReader, m, nenv, sink, tcaug.tcaug_abstract, false, reqdTy, dispatchSlots, availPriorOverrides, overrides)
-
-                    // Tell the user to mark the thing abstract if it was missing implementations
-                    if not allCorrect && not tcaug.tcaug_abstract && not (isInterfaceTy g reqdTy) then 
-                        errorR(TypeIsImplicitlyAbstract(m))
+                    let _ = CheckDispatchSlotsAreImplemented (denv, infoReader, m, nenv, sink, tcaug.tcaug_abstract, false, reqdTy, dispatchSlots, availPriorOverrides, overrides)
 
                     let overridesToCheck = 
                         allImmediateMembersThatMightImplementDispatchSlots 
@@ -882,7 +877,7 @@ module DispatchSlotChecking =
             overrideBy.MemberInfo.Value.ImplementedSlotSigs <- overriden)
 
 /// "Type Completion" inference and a few other checks at the end of the inference scope
-let FinalTypeDefinitionChecksAtEndOfInferenceScope (infoReader: InfoReader, nenv, sink, isImplementation, denv, tycon: Tycon) =
+let FinalTypeDefinitionChecksAtEndOfInferenceScope (infoReader: InfoReader, nenv: NameResolutionEnv, sink: TcResultsSink, isImplementation, denv: DisplayEnv, tycon: Tycon) =
 
     let g = infoReader.g
     let amap = infoReader.amap

src/Compiler/Checking/MethodOverrides.fsi

@@ -77,8 +77,6 @@ type SlotImplSet =
         availablePriorOverrides: OverrideInfo list *
         requiredProperties: PropInfo list
 
-exception TypeIsImplicitlyAbstract of range
-
 exception OverrideDoesntOverride of DisplayEnv * OverrideInfo * MethInfo option * TcGlobals * ImportMap * range
 
 module DispatchSlotChecking =

tests/FSharp.Compiler.ComponentTests/Conformance/GeneratedEqualityHashingComparison/Basic/Basic.fs

@@ -62,15 +62,12 @@ module Basic =
             (Error 344, Line 13, Col 6, Line 13, Col 7, "The struct, record or union type 'R' has an explicit implementation of 'Object.GetHashCode' or 'Object.Equals'. You must apply the 'CustomEquality' attribute to the type")
             (Warning 345, Line 13, Col 6, Line 13, Col 7, "The struct, record or union type 'R' has an explicit implementation of 'Object.GetHashCode'. Consider implementing a matching override for 'Object.Equals(obj)'")
             (Error 359, Line 13, Col 6, Line 13, Col 7, "More than one override implements 'GetHashCode: unit -> int'")
-            (Error 54, Line 13, Col 6, Line 13, Col 7, "This type is 'abstract' since some abstract members have not been given an implementation. If this is intentional then add the '[<AbstractClass>]' attribute to your type.")
             (Error 344, Line 17, Col 6, Line 17, Col 7, "The struct, record or union type 'U' has an explicit implementation of 'Object.GetHashCode' or 'Object.Equals'. You must apply the 'CustomEquality' attribute to the type")
             (Warning 345, Line 17, Col 6, Line 17, Col 7, "The struct, record or union type 'U' has an explicit implementation of 'Object.GetHashCode'. Consider implementing a matching override for 'Object.Equals(obj)'")
             (Error 359, Line 17, Col 6, Line 17, Col 7, "More than one override implements 'GetHashCode: unit -> int'")
-            (Error 54, Line 17, Col 6, Line 17, Col 7, "This type is 'abstract' since some abstract members have not been given an implementation. If this is intentional then add the '[<AbstractClass>]' attribute to your type.")
             (Error 344, Line 21, Col 6, Line 21, Col 7, "The struct, record or union type 'S' has an explicit implementation of 'Object.GetHashCode' or 'Object.Equals'. You must apply the 'CustomEquality' attribute to the type")
             (Warning 345, Line 21, Col 6, Line 21, Col 7, "The struct, record or union type 'S' has an explicit implementation of 'Object.GetHashCode'. Consider implementing a matching override for 'Object.Equals(obj)'")
             (Error 359, Line 21, Col 6, Line 21, Col 7, "More than one override implements 'GetHashCode: unit -> int'")
-            (Error 54, Line 21, Col 6, Line 21, Col 7, "This type is 'abstract' since some abstract members have not been given an implementation. If this is intentional then add the '[<AbstractClass>]' attribute to your type.")
            ]
 
     // SOURCE=E_ExceptionsNoComparison.fs SCFLAGS="--test:ErrorRanges"          # E_ExceptionsNoComparison.fs