On Fri, Aug 21, 2020 at 4:01 PM Jens Axboe <axboe@xxxxxxxxx> wrote:
>
> The tree is totally warning clean right now on build, but that's usually
> not the case, and missing a single warning isn't that hard.
Actually, my tree is generally entirely warning-free and has been for
years, because I absolutely hate warnings.
You're not the only person I haven't pulled from because I saw a
single warning. This is the second one just this release window. I'm
not singling you out. A warning to me is simply a hard "No".
Because I know very well that if there is even a single warning,
people will then ignore the other warnings.
So there is no such thing as a harmless warning - it doesn't matter
_what_ it warns about, it's a bad thing, because even one bogus
warning will then mean that people ignore warnings that _aren't_
bogus, and it goes all downhill from there.
So the reason I notice is exactly because I keep my build tree 100%
clean. I do allmodconfig builds that are entirely clean, and I check
it after each and every pull I do, and each patch series I apply.
Mistakes can happen, but I try _very_ hard to keep my tree clean.
Now, that said, I'll miss warnings too, because I don't do
cross-builds for other architectures, and I really only do a couple of
fairly basic configurations.
But perhaps more importantly - I don't build with a lot of different
compilers. I do in fact test two different compilers (both gcc and
clang), but I use two different configurations, so it's not really
overlapping testing, it's more that these days I make sure the clang
build is warning free at least for the core kernel too.
So "warning free" is always relative to some compiler base (and some
config base). But the baseline should absolutely be "zero warnings".
Generally, new warnings in my tree is because of a compiler upgrade or
similar congifuration issues.
And it's sadly the "different compilers" thing that then means that
*my* clean tree might not then necessarily be clean for others. It's
also why I can't just enable "-Werror" to make it harder to miss.
But I've been tempted. Many times. There's been a couple of times I've
added that "-Werror" to the Makefile, only to never commit it.
But if you have warnings that you see due to different compilers or
configurations, holler. We'll get them fixed.
Linus
