On Mon, Oct 5, 2020 at 9:49 PM Andrew Lunn <andrew@xxxxxxx> wrote: > > > 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. > > 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 :-( It depends a lot on what portion of the kernel gets enabled for W=1. As long as it's only drivers that are actively maintained, and they make up a fairly small portion of all code, it should not be a problem to find someone to fix useful warnings. The only reason to add a flag to W=1 would be that the bugs it reports are important enough to look at the false positives and address those as well. Whoever decided to enable W=1 by default for their subsystem should then also be interested in adding the new warnings. If I wanted to add a new flag to W=1 and this introduces output for allmodconfig, I would start by mailing that output to the respective maintainers. Arnd
