Merge main to release/dev17.8

src/Compiler/Checking/CheckFormatStrings.fs

@@ -458,6 +458,8 @@ let parseFormatStringInternal
 
             // residue of hole "...{n}..." in interpolated strings become %P(...)
             | 'P' when isInterpolated ->
+                let (code, message) = FSComp.SR.alwaysUseTypedStringInterpolation()
+                warning(DiagnosticWithText(code, message, m))
                 checkOtherFlags ch
                 let i = requireAndSkipInterpolationHoleFormat (i+1)
                 // Note, the fragCol doesn't advance at all as these are magically inserted.

src/Compiler/Driver/CompilerDiagnostics.fs

@@ -377,13 +377,14 @@ type PhasedDiagnostic with
         | 1182 -> false // chkUnusedValue - off by default
         | 3180 -> false // abImplicitHeapAllocation - off by default
         | 3186 -> false // pickleMissingDefinition - off by default
-        | 3366 -> false //tcIndexNotationDeprecated - currently off by default
+        | 3366 -> false // tcIndexNotationDeprecated - currently off by default
         | 3517 -> false // optFailedToInlineSuggestedValue - off by default
         | 3388 -> false // tcSubsumptionImplicitConversionUsed - off by default
         | 3389 -> false // tcBuiltInImplicitConversionUsed - off by default
         | 3390 -> false // xmlDocBadlyFormed - off by default
         | 3395 -> false // tcImplicitConversionUsedForMethodArg - off by default
         | 3559 -> false // typrelNeverRefinedAwayFromTop - off by default
+        | 3579 -> false // alwaysUseTypedStringInterpolation - off by default
         | _ ->
             match x.Exception with
             | DiagnosticEnabledWithLanguageFeature (_, _, _, enabled) -> enabled

src/Compiler/FSComp.txt

@@ -1721,3 +1721,4 @@ featureAccessorFunctionShorthand,"underscore dot shorthand for accessor only fun
 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')."
 featureUnmanagedConstraintCsharpInterop,"Interop between C#'s and F#'s unmanaged generic constraint (emit additional modreq)"
 3578,chkCopyUpdateSyntaxInAnonRecords,"This expression is an anonymous record, use {{|...|}} instead of {{...}}."
+3579,alwaysUseTypedStringInterpolation,"Interpolated string contains untyped identifiers. Adding typed format specifiers is recommended."

src/Compiler/Service/ServiceParsedInputOps.fs

@@ -1418,7 +1418,12 @@ module ParsedInput =
 
                     | _ -> None
 
-                member _.VisitBinding(path, defaultTraverse, (SynBinding (headPat = headPat; trivia = trivia) as synBinding)) =
+                member _.VisitBinding
+                    (
+                        path,
+                        defaultTraverse,
+                        (SynBinding (headPat = headPat; trivia = trivia; returnInfo = returnInfo) as synBinding)
+                    ) =
 
                     let isOverride leadingKeyword =
                         match leadingKeyword with
@@ -1431,38 +1436,41 @@ module ParsedInput =
                             Some(CompletionContext.MethodOverride enclosingType.idRange)
                         | _ -> Some CompletionContext.Invalid
 
-                    match headPat with
+                    match returnInfo with
+                    | Some (SynBindingReturnInfo (range = m)) when rangeContainsPos m pos -> Some CompletionContext.Type
+                    | _ ->
+                        match headPat with
 
-                    // override _.|
-                    | SynPat.FromParseError _ when isOverride trivia.LeadingKeyword -> overrideContext path
+                        // override _.|
+                        | SynPat.FromParseError _ when isOverride trivia.LeadingKeyword -> overrideContext path
 
-                    // override this.|
-                    | SynPat.Named(ident = SynIdent (ident = selfId)) when
-                        isOverride trivia.LeadingKeyword && selfId.idRange.End.IsAdjacentTo pos
-                        ->
-                        overrideContext path
+                        // override this.|
+                        | SynPat.Named(ident = SynIdent (ident = selfId)) when
+                            isOverride trivia.LeadingKeyword && selfId.idRange.End.IsAdjacentTo pos
+                            ->
+                            overrideContext path
 
-                    // override this.ToStr|
-                    | SynPat.LongIdent(longDotId = SynLongIdent(id = [ _; methodId ])) when
-                        isOverride trivia.LeadingKeyword && rangeContainsPos methodId.idRange pos
-                        ->
-                        overrideContext path
+                        // override this.ToStr|
+                        | SynPat.LongIdent(longDotId = SynLongIdent(id = [ _; methodId ])) when
+                            isOverride trivia.LeadingKeyword && rangeContainsPos methodId.idRange pos
+                            ->
+                            overrideContext path
 
-                    | SynPat.LongIdent (longDotId = lidwd; argPats = SynArgPats.Pats pats; range = m) when rangeContainsPos m pos ->
-                        if rangeContainsPos lidwd.Range pos then
-                            // let fo|o x = ()
-                            Some CompletionContext.Invalid
-                        else
-                            pats
-                            |> List.tryPick (fun pat -> TryGetCompletionContextInPattern true pat None pos)
-                            |> Option.orElseWith (fun () -> defaultTraverse synBinding)
+                        | SynPat.LongIdent (longDotId = lidwd; argPats = SynArgPats.Pats pats; range = m) when rangeContainsPos m pos ->
+                            if rangeContainsPos lidwd.Range pos then
+                                // let fo|o x = ()
+                                Some CompletionContext.Invalid
+                            else
+                                pats
+                                |> List.tryPick (fun pat -> TryGetCompletionContextInPattern true pat None pos)
+                                |> Option.orElseWith (fun () -> defaultTraverse synBinding)
 
-                    | SynPat.Named (range = range)
-                    | SynPat.As (_, SynPat.Named (range = range), _) when rangeContainsPos range pos ->
-                        // let fo|o = 1
-                        Some CompletionContext.Invalid
+                        | SynPat.Named (range = range)
+                        | SynPat.As (_, SynPat.Named (range = range), _) when rangeContainsPos range pos ->
+                            // let fo|o = 1
+                            Some CompletionContext.Invalid
 
-                    | _ -> defaultTraverse synBinding
+                        | _ -> defaultTraverse synBinding
 
                 member _.VisitHashDirective(_, _directive, range) =
                     // No completions in a directive