Better anonymous record error reporting

src/Compiler/Checking/CheckExpressions.fs

@@ -1796,12 +1796,20 @@ let FreshenAbstractSlot g amap m synTyparDecls absMethInfo =
     let retTyFromAbsSlot = retTy |> GetFSharpViewOfReturnType g |> instType typarInstFromAbsSlot
     typarsFromAbsSlotAreRigid, typarsFromAbsSlot, argTysFromAbsSlot, retTyFromAbsSlot
 
+let private CheckCopyUpdateSyntaxInAnonRecords sink (g: TcGlobals) ty (tyIdent: Ident option) (fldId: Ident) nenv ad =
+    match TryFindAnonRecdFieldOfType g ty fldId.idText, tyIdent with
+    | Some item, Some tpId ->
+        CallNameResolutionSink sink (fldId.idRange, nenv, item, emptyTyparInst, ItemOccurence.UseInType, ad)
+        error(Error(FSComp.SR.chkCopyUpdateSyntaxInAnonRecords(item.DisplayNameCore, tpId.idText, fldId.idText), fldId.idRange))
+    | _, _ ->
+        error(UndefinedName(0, FSComp.SR.undefinedNameRecordLabel, fldId, NoSuggestions))
+
 //-------------------------------------------------------------------------
 // Helpers to typecheck expressions and patterns
 //-------------------------------------------------------------------------
 
 /// Helper used to check record expressions and record patterns
-let BuildFieldMap (cenv: cenv) env isPartial ty (flds: ((Ident list * Ident) * 'T) list) m =
+let BuildFieldMap (cenv: cenv) env isPartial ty (tyIdent: Ident option) (flds: ((Ident list * Ident) * 'T) list) m =
     let g = cenv.g
     let ad = env.eAccessRights
 
@@ -1813,10 +1821,14 @@ let BuildFieldMap (cenv: cenv) env isPartial ty (flds: ((Ident list * Ident) * '
         let allFields = flds |> List.map (fun ((_, ident), _) -> ident)
         flds
         |> List.choose (fun (fld, fldExpr) ->
+            let fldPath, fldId = fld
             try
-                let fldPath, fldId = fld
-                let frefSet = ResolveField cenv.tcSink cenv.nameResolver env.eNameResEnv ad ty fldPath fldId allFields
-                Some(fld, frefSet, fldExpr)
+                if isAnonRecdTy cenv.g ty || isStructAnonRecdTy cenv.g ty then
+                    CheckCopyUpdateSyntaxInAnonRecords cenv.tcSink cenv.g ty tyIdent fldId env.eNameResEnv ad
+                    None
+                else
+                    let frefSet = ResolveField cenv.tcSink cenv.nameResolver env.eNameResEnv ad ty fldPath fldId allFields
+                    Some(fld, frefSet, fldExpr)
             with e ->
                 errorRecoveryNoRange e
                 None
@@ -7388,7 +7400,11 @@ and TcRecdExpr cenv overallTy env tpenv (inherits, withExprOpt, synRecdFields, m
         match flds with
         | [] -> []
         | _ ->
-            match BuildFieldMap cenv env hasOrigExpr overallTy flds mWholeExpr with
+            let tyIdent =
+                match withExprOpt with
+                | Some (SynExpr.Ident ident, _) -> Some ident
+                | _ -> None
+            match BuildFieldMap cenv env hasOrigExpr overallTy tyIdent flds mWholeExpr with
             | None -> []
             | Some(tinst, tcref, _, fldsList) ->
 

src/Compiler/Checking/CheckExpressions.fsi

@@ -893,6 +893,7 @@ val BuildFieldMap:
     env: TcEnv ->
     isPartial: bool ->
     ty: TType ->
+    tyIdent: Ident option ->
     flds: ((Ident list * Ident) * 'T) list ->
     m: range ->
         (TypeInst * TyconRef * Map<string, 'T> * (string * 'T) list) option

src/Compiler/Checking/CheckPatterns.fs

@@ -441,7 +441,7 @@ and TcPatArrayOrList warnOnUpper cenv env vFlags patEnv ty isArray args m =
 
 and TcRecordPat warnOnUpper cenv env vFlags patEnv ty fieldPats m =
     let fieldPats = fieldPats |> List.map (fun (fieldId, _, fieldPat) -> fieldId, fieldPat)
-    match BuildFieldMap cenv env true ty fieldPats m with
+    match BuildFieldMap cenv env true ty None fieldPats m with
     | None -> (fun _ -> TPat_error m), patEnv
     | Some(tinst, tcref, fldsmap, _fldsList) ->
 

src/Compiler/Checking/NameResolution.fs

@@ -3716,8 +3716,7 @@ let ResolveFieldPrim sink (ncenv: NameResolver) nenv ad ty (mp, id: Ident) allFi
                     error(ErrorWithSuggestions(errorText, m, id.idText, suggestLabels))
                 else
                     lookup()
-        | _ ->
-            lookup()
+        | ValueNone -> lookup()
     | _ ->
         let lid = (mp@[id])
         let tyconSearch ad () =

src/Compiler/FSComp.txt

@@ -1708,4 +1708,5 @@ featureAccessorFunctionShorthand,"underscore dot shorthand for accessor only fun
 3569,chkNotTailRecursive,"The member or function '%s' has the 'TailCallAttribute' attribute, but is not being used in a tail recursive way."
 3570,tcStaticBindingInExtrinsicAugmentation,"Static bindings cannot be added to extrinsic augmentations. Consider using a 'static member' instead."
 3571,pickleFsharpCoreBackwardsCompatible,"Newly added pickle state cannot be used in FSharp.Core, since it must be working in older compilers+tooling as well. The time window is at least 3 years after feature introduction. Violation: %s . Context: \n %s "
-3577,tcOverrideUsesMultipleArgumentsInsteadOfTuple,"This override takes a tuple instead of multiple arguments. Try to add an additional layer of parentheses at the method definition (e.g. 'member _.Foo((x, y))'), or remove parentheses at the abstract method declaration (e.g. 'abstract member Foo: 'a * 'b -> 'c')."
+3577,tcOverrideUsesMultipleArgumentsInsteadOfTuple,"This override takes a tuple instead of multiple arguments. Try to add an additional layer of parentheses at the method definition (e.g. 'member _.Foo((x, y))'), or remove parentheses at the abstract method declaration (e.g. 'abstract member Foo: 'a * 'b -> 'c')."
+3578,chkCopyUpdateSyntaxInAnonRecords,"Label '%s' is part of anonymous record. Use {{| %s with %s = ... |}} instead."