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From: Ingo Molnar <mingo@kernel.org>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>, Sam Ravnborg <sam@ravnborg.org>,
	lkml <linux-kernel@vger.kernel.org>, Michael Matz <matz@suse.de>,
	Linux Kbuild mailing list <linux-kbuild@vger.kernel.org>,
	x86-ml <x86@kernel.org>
Subject: Re: [PATCH] Kbuild: Move -Wmaybe-uninitialized to W=1
Date: Thu, 28 Jul 2016 22:28:14 +0200	[thread overview]
Message-ID: <20160728202814.GA16950@gmail.com> (raw)
In-Reply-To: <CA+55aFxSTYww0ZJ75q9p4RRwPVSxGji-OJ8vYdjVXuFs-2H3dw@mail.gmail.com>


* Linus Torvalds <torvalds@linux-foundation.org> wrote:

> On Thu, Jul 28, 2016 at 12:03 PM, Linus Torvalds
> <torvalds@linux-foundation.org> wrote:
> >
> > Once we get to the point that the warning is no longer useful, and is more 
> > pain than gain, it gets disabled.
> 
> Btw, I have a suspicion that you didn't realize that "-Wmaybe-uninitialized" is 
> separate from "-Wuninitialized" (which is *not* disabled).

I very much know the difference, as you can see from the commit IDs I cited.

> The "maybe-uninitialized" warning is literally gcc saying "I haven't really 
> followed all the logic, but from my broken understanding it isn't _obvious_ that 
> it is initialized".
> 
> And the problem is that a lot of gcc optimization choices basically move the 
> pointer of "obvious". So the warning is a bit random to begin with. And when the 
> gcc people screw thigns up, things go to hell in a handbasket.

Fair enough.

Thanks,

	Ingo

  reply	other threads:[~2016-07-28 20:28 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-06-16 13:20 [RFC] Turn off -Wmaybe-uninitialized completely and move it to W=1 Borislav Petkov
2014-06-16 21:14 ` Sam Ravnborg
2014-06-24 21:38   ` [PATCH] Kbuild: Move -Wmaybe-uninitialized " Borislav Petkov
2014-07-07 10:53     ` Borislav Petkov
2014-07-08  9:25       ` Paul Bolle
2014-07-08 11:37         ` Borislav Petkov
2014-07-10 10:42           ` Borislav Petkov
2014-07-10 11:03             ` Paul Bolle
2016-07-28  4:20       ` Borislav Petkov
2016-07-28  8:29         ` Ingo Molnar
2016-07-28  8:46           ` Borislav Petkov
2016-07-28 16:49             ` Ingo Molnar
2016-07-28 17:04               ` Ingo Molnar
2016-07-28 17:56             ` Markus Trippelsdorf
2016-07-28 19:03           ` Linus Torvalds
2016-07-28 19:08             ` Linus Torvalds
2016-07-28 20:28               ` Ingo Molnar [this message]
2016-07-28 21:22             ` Linus Torvalds
2016-07-29 10:08               ` Arnd Bergmann
2016-07-29 10:19                 ` Borislav Petkov
2016-07-29 10:35                   ` Arnd Bergmann
2016-07-29 18:26                   ` Linus Torvalds

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