Allow F# compiler directives like #nowarn to span less than an entire file.

[baronfel]

Submitted by Robert Nielsen on 6/22/2014 12:00:00 AM
7 votes on UserVoice prior to migration

Idea posted here:
http://visualstudio.uservoice.com/forums/121579-visual-studio/suggestions/3338653-allow-f-compiler-directives-like-nowarn-to-span
A possibly related issue / suggestion is listed here:
/archive/suggestion-5676502-disable-compiler-warnings-per-line

Original UserVoice Submission
Archived Uservoice Comments

[gusty]

Is this approved?

I think it's important not to disable warnings unintentionally.

Maybe something like:

#nowarn "44"
 ...
#endnowarn "44"

or just:

#nowarn "44"
...
#warn "44"    

[abelbraaksma]

@gusty, I agree, I really miss this feature in everyday development. Something like nowarnonce "44" may be another alternative.

[dsyme]

Is there a corresponding C# feature? (sorry - on mobile, haven't checked...)

If so we should maintain alignment

[OnurGumus]

@dsyme #pragma warning disable

https://docs.microsoft.com/en-us/dotnet/csharp/language-reference/preprocessor-directives/preprocessor-pragma-warning

[abelbraaksma]

Is there a corresponding C# feature? (sorry - on mobile, haven't checked...)
If so we should maintain alignment

@dsyme, I believe we are quite behind with alignment when it comes down to compiler directives and similar statements. We support only a small amount of them. Think of #line, #region, #define and pragma warning disable in conjunction with pragma warning restore.

In C# they don't have #pragma warning disable once, but it would definitely be a nice-to-have. I don't think we need to stick to the #pragma syntax, expaning on #nowarn seems fine with me.

[gusty]

Having to disable many potential warnings in order to address a single one is an issue and AFAIK there is no workaround it.

I'm currently being impacted by this issue in a real world project.

[ReedCopsey]

C# does this well with #pragma warning. I'd vote to steal their approach, as it seems like less friction when using both in solutions: https://docs.microsoft.com/en-us/dotnet/csharp/language-reference/preprocessor-directives/preprocessor-pragma-warning I like that you can disable multiple warnings, and reenable selectively if needed.

…

On Fri, May 4, 2018, 8:13 AM Gustavo Leon ***@***.***> wrote: Having to disable many potential warnings in order to address a single one is an issue and AFAIK there is no workaround it. I'm currently being impacted by this issue in a real world project. — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#278 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AFCUmouiHRzyNEvuCu2tD_emP8Bealxuks5tvHACgaJpZM4KbqYL> .

[abelbraaksma]

@ReedCopsey, I agree, with the caveat that we already have the #nowarn syntax and no #pragma syntax. It may be more orthogonal to stay close to the syntax we already have. I'd think of #nowarn once or current syntax plus #warn enable to re-enable a set of warnings.

While we're at it, I'd like to suggest alignment with #warning and #error in C# as well. I really miss the #warning, which can help keep large code bases sane by adding warnings on tricky code paths that require attention in the near future (not the same as, but related to, //TODO, which is currently not recognized automatically either, but is so in C#).

[kkm000]

@abelbraaksma, I am a little concerned about the scope of #nowarn once. What happens if you put the directive before the construct that causes a warning, but then change it in a way the warning is no longer issued? Will this inadvertently suppress the same warning below?

Explicit #nowarn/#warn brackets, akin to C#, or VC++ stack-style exclusions, e. g. #nowarn "42" "44" push/#nowarn pop, look safer in this regard.

[kkm000]

@dsyme, is this ready for a "needs rfc" status?

[dsyme]

@kkm000 Yes - For this sort of thing we're pretty much always happy to follow the C# approach to the same problem, as long as it is fully implemented and tested.