Subject: Re: [PATCH net-next v2 1/2] Makefile.extrawarn: Add symbol for W=1 warnings for today

From: Andrew Lunn <[email-masked]>
Date: Mon, 5 Oct 2020 21:49:13 +0200

> Sorry, to be more specific about my concern; I like the idea of
> exporting the W=* flags, then selectively applying them via
> subdir-ccflags-y.  I don't like the idea of supporting W=1 as defined
> at a precise point in time via multiple date specific symbols.  If
> someone adds something to W=1, then they should need to ensure subdirs
> build warning-free, so I don't think you need to "snapshot" W=1 based
> on what it looked like on 20200930.

Hi Nick

That then contradicts what Masahiro Yamada said to the first version i
posted:

https://www.spinics.net/lists/netdev/msg685284.html
> With this patch series applied, where should we add -Wfoo-bar?
> Adding it to W=1 would emit warnings under drivers/net/ since W=1 is
> now the default for the net subsystem.

The idea with the date stamps was to allow new warnings to be added to
W=1 without them immediately causing warnings on normal builds. You
are saying that whoever adds a new warning to W=1 needs to cleanup the
tree which is already W=1 clean? That might have the side effect that
no more warnings are added to W=1 :-(

   Andrew