Date: Sun, 1 Oct 2006 11:16:48 -0700
From: Randy Dunlap <rdunlap@xenotime.net>
To: Jeff Garzik <jeff@garzik.org>
Cc: Linux Kernel <linux-kernel@vger.kernel.org>, Andrew Morton <akpm@osdl.org>
Subject: Re: Announce: gcc bogus warning repository
Message-Id: <20061001111648.226596a8.rdunlap@xenotime.net>
In-Reply-To: <451FF8ED.9080507@garzik.org>
References: <451FC657.6090603@garzik.org>
	<20061001100747.d1842273.rdunlap@xenotime.net>
	<451FF8ED.9080507@garzik.org>
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On Sun, 01 Oct 2006 13:20:45 -0400 Jeff Garzik wrote:

> Randy Dunlap wrote:
> > On Sun, 01 Oct 2006 09:44:55 -0400 Jeff Garzik wrote:
> > 
> >> The level of warnings in a kernel build has lately increased to the 
> >> point where it is hiding bugs and otherwise making life difficult.
> >>
> >> In particular, recent gcc versions throw warnings when it thinks a 
> >> variable "MAY be used uninitialized", which is not terribly helpful due 
> >> to the fact that most of these warnings are bogus.
> >>
> >> For those that may find this valuable, I have started a git repo that 
> >> silences these bogus warnings, after careful auditing of code paths to 
> >> ensure that the warning truly is bogus.
> >>
> >> The results may be found in the "gccbug" branch of
> >> git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/misc-2.6.git
> >>
> >> This repository will NEVER EVER be pushed upstream.  It exists solely 
> >> for those who want to decrease their build noise, thereby exposing true 
> >> bugs.
> >>
> >> The audit has already uncovered several minor bugs, lending credence to 
> >> my theory that too many warnings hides bugs.
> > 
> > I usually build with must_check etc. enabled then grep them
> > away if I want to look for other messages.  I think that the situation
> > is not so disastrous.
> 
> I think it's both sad, and telling, that the high level of build noise 
> has trained kernel hackers to tune out warnings, and/or build tools of 
> ever-increasing sophistication just to pick out the useful messages from 
> all the noise.
> 
> If you have to grep useful stuff out of the noise, you've already lost.

I often build with C=1 (sparse checking), so the amount of output
has to be grepped IMO.  It's certainly too much to read otherwise.
We just have different perspectives, I guess.

---
~Randy
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