Bugfix :: Nullness in signature file is not considered by implementation and vice versa

src/Compiler/AbstractIL/ilreflect.fs

@@ -2548,7 +2548,7 @@ let EmitDynamicAssemblyFragment
             ignore (typB.InvokeMemberAndLog(methodName, BindingFlags.InvokeMethod ||| BindingFlags.Public ||| BindingFlags.Static, [||]))
             None
         with :? TargetInvocationException as exn ->
-            Some exn.InnerException
+            Option.ofObj exn.InnerException
 
     let emEnv, entryPts = envPopEntryPts emEnv
     let execs = List.map execEntryPtFun entryPts

src/Compiler/Checking/CheckDeclarations.fs

@@ -4244,7 +4244,7 @@ module TcDeclarations =
                 // For historical reasons we only give a warning for incorrect type parameters on intrinsic extensions
                 if nReqTypars <> synTypars.Length then 
                     errorR(Error(FSComp.SR.tcDeclaredTypeParametersForExtensionDoNotMatchOriginal(tcref.DisplayNameWithStaticParametersAndUnderscoreTypars), m))
-                if not (typarsAEquiv g TypeEquivEnv.Empty reqTypars declaredTypars) then 
+                if not (typarsAEquiv g (TypeEquivEnv.EmptyWithNullChecks g) reqTypars declaredTypars) then 
                     warning(Error(FSComp.SR.tcDeclaredTypeParametersForExtensionDoNotMatchOriginal(tcref.DisplayNameWithStaticParametersAndUnderscoreTypars), m))
                 // Note we return 'reqTypars' for intrinsic extensions since we may only have given warnings
                 IntrinsicExtensionBinding, reqTypars
@@ -4253,7 +4253,7 @@ module TcDeclarations =
                     errorR(Error(FSComp.SR.tcMembersThatExtendInterfaceMustBePlacedInSeparateModule(), tcref.Range))
                 if nReqTypars <> synTypars.Length then 
                     error(Error(FSComp.SR.tcDeclaredTypeParametersForExtensionDoNotMatchOriginal(tcref.DisplayNameWithStaticParametersAndUnderscoreTypars), m))
-                if not (typarsAEquiv g TypeEquivEnv.Empty reqTypars declaredTypars) then 
+                if not (typarsAEquiv g (TypeEquivEnv.EmptyWithNullChecks g) reqTypars declaredTypars) then 
                     errorR(Error(FSComp.SR.tcDeclaredTypeParametersForExtensionDoNotMatchOriginal(tcref.DisplayNameWithStaticParametersAndUnderscoreTypars), m))
                 ExtrinsicExtensionBinding, declaredTypars
 
@@ -5695,7 +5695,7 @@ let CheckModuleSignature g (cenv: cenv) m denvAtEnd rootSigOpt implFileTypePrior
                 |]
 
         // We want to show imperative type variables in any types in error messages at this late point 
-        let denv = { denvAtEnd with showInferenceTyparAnnotations=true }
+        let denv = { denvAtEnd with showInferenceTyparAnnotations=true;showNullnessAnnotations=Some g.checkNullness }
         try 
 
             // As typechecked the signature and implementation use different tycons etc. 
@@ -5707,7 +5707,7 @@ let CheckModuleSignature g (cenv: cenv) m denvAtEnd rootSigOpt implFileTypePrior
             // Compute the remapping from implementation to signature
             let remapInfo, _ = ComputeRemappingFromInferredSignatureToExplicitSignature g implFileTypePriorToSig sigFileType
 
-            let aenv = { TypeEquivEnv.Empty with EquivTycons = TyconRefMap.OfList remapInfo.RepackagedEntities }
+            let aenv = { TypeEquivEnv.EmptyWithNullChecks g with EquivTycons = TyconRefMap.OfList remapInfo.RepackagedEntities }
 
             if not (SignatureConformance.Checker(g, cenv.amap, denv, remapInfo, true).CheckSignature aenv cenv.infoReader (mkLocalModuleRef implFileSpecPriorToSig) sigFileType) then
                 // We can just raise 'ReportedError' since CheckModuleOrNamespace raises its own error 

src/Compiler/Checking/ConstraintSolver.fs

@@ -344,7 +344,7 @@ let MakeConstraintSolverEnv contextInfo css m denv =
       eContextInfo = contextInfo
       MatchingOnly = false
       ErrorOnFailedMemberConstraintResolution = false
-      EquivEnv = TypeEquivEnv.Empty 
+      EquivEnv = TypeEquivEnv.EmptyIgnoreNulls
       DisplayEnv = denv
       IsSpeculativeForMethodOverloading = false
       IsSupportsNullFlex = false

src/Compiler/Checking/Expressions/CheckExpressions.fs

@@ -12670,7 +12670,7 @@ and FixupLetrecBind (cenv: cenv) denv generalizedTyparsForRecursiveBlock (bind:
     | Some _ ->
        match PartitionValTyparsForApparentEnclosingType g vspec with
        | Some(parentTypars, memberParentTypars, _, _, _) ->
-          ignore(SignatureConformance.Checker(g, cenv.amap, denv, SignatureRepackageInfo.Empty, false).CheckTypars vspec.Range TypeEquivEnv.Empty memberParentTypars parentTypars)
+          ignore(SignatureConformance.Checker(g, cenv.amap, denv, SignatureRepackageInfo.Empty, false).CheckTypars vspec.Range TypeEquivEnv.EmptyIgnoreNulls memberParentTypars parentTypars)
        | None ->
           errorR(Error(FSComp.SR.tcMemberIsNotSufficientlyGeneric(), vspec.Range))
     | _ -> ()

src/Compiler/Checking/MethodOverrides.fs

@@ -269,7 +269,7 @@ module DispatchSlotChecking =
         // Compare the types. CompiledSigOfMeth, GetObjectExprOverrideInfo and GetTypeMemberOverrideInfo have already 
         // applied all relevant substitutions except the renamings from fvtmps <-> methTypars 
 
-        let aenv = TypeEquivEnv.FromEquivTypars fvmethTypars methTypars 
+        let aenv = (TypeEquivEnv.EmptyIgnoreNulls).FromEquivTypars fvmethTypars methTypars 
 
         List.forall2 (List.lengthsEqAndForall2 (typeAEquiv g aenv)) vargTys argTys &&
         returnTypesAEquiv g aenv vrty retTy &&
@@ -305,7 +305,7 @@ module DispatchSlotChecking =
                 ComposeTyparInsts ttpinst (ReverseTyparRenaming g memberToParentInst)
 
         // Compare under the composed substitutions 
-        let aenv = TypeEquivEnv.FromTyparInst ttpinst 
+        let aenv = (TypeEquivEnv.EmptyIgnoreNulls).FromTyparInst ttpinst 
 
         typarsAEquiv g aenv fvmethTypars methTypars
 

src/Compiler/Checking/NicePrint.fs

@@ -764,7 +764,7 @@ module PrintTypes =
             |> ListSet.setify (fun (_, cx1) (_, cx2) ->
                 match cx1, cx2 with 
                 | TyparConstraint.MayResolveMember(traitInfo1, _),
-                  TyparConstraint.MayResolveMember(traitInfo2, _) -> traitsAEquiv denv.g TypeEquivEnv.Empty traitInfo1 traitInfo2
+                  TyparConstraint.MayResolveMember(traitInfo2, _) -> traitsAEquiv denv.g (TypeEquivEnv.EmptyWithNullChecks denv.g) traitInfo1 traitInfo2
                 | _ -> false)
 
         let cxsL = List.collect (layoutConstraintWithInfo denv env) cxs

src/Compiler/Checking/SignatureConformance.fs

@@ -352,14 +352,22 @@ type Checker(g, amap, denv, remapInfo: SignatureRepackageInfo, checkingSig) =
             else 
                 let implTypars, implValTy = implVal.GeneralizedType
                 let sigTypars, sigValTy = sigVal.GeneralizedType
-                if implTypars.Length <> sigTypars.Length then (err {denv with showTyparBinding=true} FSComp.SR.ValueNotContainedMutabilityParameterCountsDiffer) else
-                let aenv = aenv.BindEquivTypars implTypars sigTypars 
-                checkTypars m aenv implTypars sigTypars &&
-                if not (typeAEquiv g aenv implValTy sigValTy) then err denv FSComp.SR.ValueNotContainedMutabilityTypesDiffer
-                elif not (checkValInfo aenv (err denv) implVal sigVal) then false
-                elif implVal.IsExtensionMember <> sigVal.IsExtensionMember then err denv FSComp.SR.ValueNotContainedMutabilityExtensionsDiffer
-                elif not (checkMemberDatasConform (err denv) (implVal.Attribs, implVal, implVal.MemberInfo) (sigVal.Attribs, sigVal, sigVal.MemberInfo)) then false
-                else checkAttribs aenv implVal.Attribs sigVal.Attribs (fun attribs -> implVal.SetAttribs attribs)              
+                if implTypars.Length <> sigTypars.Length then (err {denv with showTyparBinding=true} FSComp.SR.ValueNotContainedMutabilityParameterCountsDiffer) 
+                else
+                    let aenv = aenv.BindEquivTypars implTypars sigTypars 
+                    checkTypars m aenv implTypars sigTypars &&
+                        let strictTyEquals = typeAEquiv g aenv implValTy sigValTy
+                        let onlyDiffersInNullness = not(strictTyEquals) && g.checkNullness && typeAEquiv g {aenv with NullnessMustEqual = false} implValTy sigValTy
+
+                        // The types would be equal if we did not have nullness checks => lets just generate a warning, not an error
+                        if onlyDiffersInNullness then
+                            warning(mk_err denv FSComp.SR.ValueNotContainedMutabilityTypesDiffer)
+
+                        if not strictTyEquals && not onlyDiffersInNullness then err denv FSComp.SR.ValueNotContainedMutabilityTypesDiffer                          
+                        elif not (checkValInfo aenv (err denv) implVal sigVal) then false
+                        elif implVal.IsExtensionMember <> sigVal.IsExtensionMember then err denv FSComp.SR.ValueNotContainedMutabilityExtensionsDiffer
+                        elif not (checkMemberDatasConform (err denv) (implVal.Attribs, implVal, implVal.MemberInfo) (sigVal.Attribs, sigVal, sigVal.MemberInfo)) then false
+                        else checkAttribs aenv implVal.Attribs sigVal.Attribs (fun attribs -> implVal.SetAttribs attribs)              
 
 
         and checkExnInfo err aenv (infoReader: InfoReader) (enclosingImplTycon: Tycon) (enclosingSigTycon: Tycon) implTypeRepr sigTypeRepr =
@@ -394,15 +402,29 @@ type Checker(g, amap, denv, remapInfo: SignatureRepackageInfo, checkingSig) =
         and checkField aenv infoReader (enclosingImplTycon: Tycon) (enclosingSigTycon: Tycon) implField sigField =
             implField.SetOtherXmlDoc(sigField.XmlDoc)
 
-            let err f = errorR(FieldNotContained(denv, infoReader, enclosingImplTycon, enclosingSigTycon, implField, sigField, f)); false
+            let diag f = FieldNotContained(denv, infoReader, enclosingImplTycon, enclosingSigTycon, implField, sigField, f)
+            let err f = errorR(diag f); false
+
+            let areTypesDifferent() =
+                let strictTyEquals = typeAEquiv g aenv implField.FormalType sigField.FormalType
+                let onlyDiffersInNullness = not(strictTyEquals) && g.checkNullness &&  typeAEquiv g {aenv with NullnessMustEqual = false} implField.FormalType sigField.FormalType
+
+                // The types would be equal if we did not have nullness checks => lets just generate a warning, not an error
+                if onlyDiffersInNullness then
+                    warning(diag FSComp.SR.FieldNotContainedTypesDiffer)
+                    false
+                else
+                    not strictTyEquals  
+
+
             sigField.rfield_other_range <- Some (implField.Range, true)
             implField.rfield_other_range <- Some (sigField.Range, false)
             if implField.rfield_id.idText <> sigField.rfield_id.idText then err FSComp.SR.FieldNotContainedNamesDiffer
             elif isLessAccessible implField.Accessibility sigField.Accessibility then err FSComp.SR.FieldNotContainedAccessibilitiesDiffer
             elif implField.IsStatic <> sigField.IsStatic then err FSComp.SR.FieldNotContainedStaticsDiffer
             elif implField.IsMutable <> sigField.IsMutable then err FSComp.SR.FieldNotContainedMutablesDiffer
             elif implField.LiteralValue <> sigField.LiteralValue then err FSComp.SR.FieldNotContainedLiteralsDiffer
-            elif not (typeAEquiv g aenv implField.FormalType sigField.FormalType) then err FSComp.SR.FieldNotContainedTypesDiffer
+            elif areTypesDifferent() then err FSComp.SR.FieldNotContainedTypesDiffer
             else 
                 checkAttribs aenv implField.FieldAttribs sigField.FieldAttribs (fun attribs -> implField.rfield_fattribs <- attribs) &&
                 checkAttribs aenv implField.PropertyAttribs sigField.PropertyAttribs (fun attribs -> implField.rfield_pattribs <- attribs)

src/Compiler/Checking/infos.fs

@@ -2503,7 +2503,7 @@ let MethInfosEquivByPartialSig erasureFlag ignoreFinal g amap m (minfo: MethInfo
     let argTys = minfo.GetParamTypes(amap, m, fminst)
     let argTys2 = minfo2.GetParamTypes(amap, m, fminst2)
     (argTys, argTys2) ||> List.lengthsEqAndForall2 (List.lengthsEqAndForall2 (fun ty1 ty2 ->
-        typeAEquivAux erasureFlag g (TypeEquivEnv.FromEquivTypars formalMethTypars formalMethTypars2) (stripByrefTy g ty1) (stripByrefTy g ty2)))
+        typeAEquivAux erasureFlag g (TypeEquivEnv.EmptyIgnoreNulls.FromEquivTypars formalMethTypars formalMethTypars2) (stripByrefTy g ty1) (stripByrefTy g ty2)))
 
 /// Used to hide/filter members from super classes based on signature
 /// Inref and outref parameter types will be treated as a byref type for equivalency.
@@ -2525,7 +2525,7 @@ let MethInfosEquivByNameAndSig erasureFlag ignoreFinal g amap m minfo minfo2 =
     let (CompiledSig(_, retTy2, formalMethTypars2, _)) = CompiledSigOfMeth g amap m minfo2
     match retTy, retTy2 with
     | None, None -> true
-    | Some retTy, Some retTy2 -> typeAEquivAux erasureFlag g (TypeEquivEnv.FromEquivTypars formalMethTypars formalMethTypars2) retTy retTy2
+    | Some retTy, Some retTy2 -> typeAEquivAux erasureFlag g (TypeEquivEnv.EmptyIgnoreNulls.FromEquivTypars formalMethTypars formalMethTypars2) retTy retTy2
     | _ -> false
 
 /// Used to hide/filter members from super classes based on signature

src/Compiler/DependencyManager/AssemblyResolveHandler.fs

@@ -113,7 +113,7 @@ type AssemblyResolveHandler internal (assemblyProbingPaths: AssemblyResolutionPr
             else
                 new AssemblyResolveHandlerDeskTop(assemblyProbingPaths) :> IDisposable)
 
-    new(assemblyProbingPaths: AssemblyResolutionProbe MaybeNull) = new AssemblyResolveHandler(Option.ofObj assemblyProbingPaths)
+    new(assemblyProbingPaths: AssemblyResolutionProbe | null) = new AssemblyResolveHandler(Option.ofObj assemblyProbingPaths)
 
     interface IDisposable with
         member _.Dispose() =

src/Compiler/DependencyManager/AssemblyResolveHandler.fsi

@@ -12,7 +12,7 @@ type AssemblyResolutionProbe = delegate of Unit -> seq<string>
 type AssemblyResolveHandler =
 
     /// Construct a new DependencyProvider
-    new: assemblyProbingPaths: AssemblyResolutionProbe -> AssemblyResolveHandler
+    new: assemblyProbingPaths: AssemblyResolutionProbe|null -> AssemblyResolveHandler
 
     /// Construct a new DependencyProvider
     internal new: assemblyProbingPaths: AssemblyResolutionProbe option -> AssemblyResolveHandler

src/Compiler/DependencyManager/NativeDllResolveHandler.fs

@@ -184,7 +184,7 @@ type NativeDllResolveHandler(nativeProbingRoots: NativeResolutionProbe option) =
         |> Option.filter (fun _ -> isRunningOnCoreClr)
         |> Option.map (fun _ -> new NativeDllResolveHandlerCoreClr(nativeProbingRoots))
 
-    new(nativeProbingRoots: NativeResolutionProbe MaybeNull) = new NativeDllResolveHandler(Option.ofObj nativeProbingRoots)
+    new(nativeProbingRoots: NativeResolutionProbe | null) = new NativeDllResolveHandler(Option.ofObj nativeProbingRoots)
 
     member internal _.RefreshPathsInEnvironment(roots: string seq) =
         handler |> Option.iter (fun handler -> handler.RefreshPathsInEnvironment(roots))

src/Compiler/DependencyManager/NativeDllResolveHandler.fsi

@@ -12,7 +12,7 @@ type NativeResolutionProbe = delegate of Unit -> seq<string>
 type NativeDllResolveHandler =
 
     /// Construct a new NativeDllResolveHandler
-    new: nativeProbingRoots: NativeResolutionProbe -> NativeDllResolveHandler
+    new: nativeProbingRoots: NativeResolutionProbe|null -> NativeDllResolveHandler
 
     /// Construct a new NativeDllResolveHandler
     internal new: nativeProbingRoots: NativeResolutionProbe option -> NativeDllResolveHandler

src/Compiler/Driver/ParseAndCheckInputs.fs

@@ -1907,7 +1907,10 @@ let CheckMultipleInputsUsingGraphMode
         let (Finisher(finisher = finisher)) =
             cancellable {
                 use _ = UseDiagnosticsLogger logger
-                let checkForErrors2 () = priorErrors || (logger.ErrorCount > 0)
+
+                let checkForErrors2 () =
+                    priorErrors || (logger.CheckForRealErrorsIgnoringWarnings)
+
                 let tcSink = TcResultsSink.NoSink
 
                 return!
@@ -1922,7 +1925,7 @@ let CheckMultipleInputsUsingGraphMode
             (fun (state: State) ->
                 let tcState, priorErrors = state
                 let (partialResult: PartialResult, tcState) = finisher tcState
-                let hasErrors = logger.ErrorCount > 0
+                let hasErrors = logger.CheckForRealErrorsIgnoringWarnings
                 let priorOrCurrentErrors = priorErrors || hasErrors
                 let state: State = tcState, priorOrCurrentErrors
                 partialResult, state)

src/Compiler/FSharp.Compiler.Service.fsproj

@@ -12,6 +12,10 @@
     <NoWarn>$(NoWarn);NU5125</NoWarn>
     <NoWarn>$(NoWarn);64;1182;1204</NoWarn>         <!--Temporary fix for sourcebuild -->
     <OtherFlags>$(OtherFlags) --warnaserror-:1182</OtherFlags>         <!--Temporary fix for sourcebuild -->
+	<OtherFlags>$(OtherFlags) --warnaserror-:34</OtherFlags>
+	  <OtherFlags>$(OtherFlags) --warnaserror-:193</OtherFlags>
+	  <!-- for the love of god I cannot see all errors at once -->
+
     <AssemblyName>FSharp.Compiler.Service</AssemblyName>
     <AllowCrossTargeting>true</AllowCrossTargeting>
     <DefineConstants>$(DefineConstants);COMPILER</DefineConstants>

src/Compiler/Facilities/CompilerLocation.fs

@@ -32,6 +32,7 @@ module internal FSharpEnvironment =
     let FSharpCoreLibRunningVersion =
         try
             match versionOf<Unit> with
+            | null -> None
             | s when String.IsNullOrEmpty(s) -> None
             | s -> Some(s)
         with _ ->

src/Compiler/Facilities/DiagnosticsLogger.fs

@@ -795,8 +795,7 @@ let NewlineifyErrorString (message: string) =
 /// fixes given string by replacing all control chars with spaces.
 /// NOTE: newlines are recognized and replaced with stringThatIsAProxyForANewlineInFlatErrors (ASCII 29, the 'group separator'),
 /// which is decoded by the IDE with 'NewlineifyErrorString' back into newlines, so that multi-line errors can be displayed in QuickInfo
-let NormalizeErrorString (text: string MaybeNull) =
-    let text = nullArgCheck "text" text
+let NormalizeErrorString (text: string) =
     let text = text.Trim()
 
     let buf = System.Text.StringBuilder()

src/Compiler/Facilities/prim-parsing.fs

@@ -5,6 +5,7 @@
 namespace Internal.Utilities.Text.Parsing
 
 open Internal.Utilities.Text.Lexing
+open Internal.Utilities.Library
 
 open System
 open System.Buffers
@@ -28,7 +29,7 @@ type internal IParseState
 
     member _.ResultEndPosition = lhsPos[1]
 
-    member _.GetInput index = ruleValues[index - 1]
+    member _.GetInput index = !!ruleValues[index - 1]
 
     member _.ResultRange = (lhsPos[0], lhsPos[1])
 
@@ -572,7 +573,7 @@ module internal Implementation =
                 else if Flags.debug then
                     Console.WriteLine("ALARM!!! drop through case in parser")
         // OK, we're done - read off the overall generated value
-        valueStack.Peep().value
+        !!valueStack.Peep().value
 
 type internal Tables<'Token> with
 

src/Compiler/SyntaxTree/PrettyNaming.fs

@@ -670,8 +670,8 @@ let IsLogicalPrefixOperator logicalName =
     if String.IsNullOrEmpty logicalName then
         false
     else
-        let displayName = ConvertValLogicalNameToDisplayNameCore !!logicalName
-        displayName <> !!logicalName && IsValidPrefixOperatorDefinitionName displayName
+        let displayName = ConvertValLogicalNameToDisplayNameCore logicalName
+        displayName <> logicalName && IsValidPrefixOperatorDefinitionName displayName
 
 let IsLogicalTernaryOperator logicalName =
     let displayName = ConvertValLogicalNameToDisplayNameCore logicalName