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From: Arnd Bergmann <arnd@arndb.de>
To: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Dan Carpenter <dan.carpenter@oracle.com>,
	ksummit@lists.linux.dev,  Julia Lawall <julia.lawall@inria.fr>
Subject: Re: Potential static analysis ideas
Date: Sat, 24 Jul 2021 16:08:38 +0200	[thread overview]
Message-ID: <CAK8P3a2K0cj-k0MHkZGeLD6UnbqWvH4nL_0eK5LGXw1ErfT2EQ@mail.gmail.com> (raw)
In-Reply-To: <CAMuHMdWwSdXppWo=sYm+ajVdR=zXzNJpP2xZWbCLdxxu55MZoA@mail.gmail.com>

On Sat, Jul 24, 2021 at 3:33 PM Geert Uytterhoeven <geert@linux-m68k.org> wrote:
>
> Hi Dan,
>
> On Fri, Jul 23, 2021 at 9:11 PM Dan Carpenter <dan.carpenter@oracle.com> wrote:
> > These days we have disabled GCC's uninitialized warnings so it falls
> > to static analysis devs to review all the new warnings.  I sometimes
> > ignore warnings if they look like probably they aren't a bug.  Does this
> > function allow zero size writes?  Does this switch statement really need
> > a default case?  Maybe sometimes I miss bugs.
>
> Yeah, I tended to find a few real bugs every release using the good old
> gcc 4.2, before support for it was dropped.
> I hope someone still runs modern compilers with GCC's uninitialized
> warnings enabled again?

Unfortunately, the new inlining in gcc-10 and up has made the
Wmaybe-uninitialized option pretty much unusable, especially since
all the uninitialized_var() annotations are gone. I tried for a while to
keep that running on my randconfig build machine, but the number of
warnings that got added was overwhelming after a while.

This does contain a number of real bugs, and at least clang and
smatch can both catch a notable subset of those, but it would be
good to have a replacement that warns developers about not
adding uninitialized variable uses in the first place.

    Arnd

  parent reply	other threads:[~2021-07-24 14:08 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-07-23 19:10 Potential static analysis ideas Dan Carpenter
2021-07-24 13:33 ` Geert Uytterhoeven
2021-07-24 13:40   ` Julia Lawall
2021-07-24 14:08   ` Arnd Bergmann [this message]
2021-07-24 23:18   ` Laurent Pinchart
2021-07-24 23:45     ` NeilBrown
2021-07-26  7:25       ` Arnd Bergmann
2021-07-26  7:53         ` Geert Uytterhoeven
2021-07-26  8:20           ` Arnd Bergmann
2021-07-26  8:39             ` Geert Uytterhoeven
2021-07-26  8:52               ` Arnd Bergmann
2021-07-26  9:11                 ` Geert Uytterhoeven
2021-07-26  8:55             ` Julia Lawall
2021-07-26  9:08               ` Hannes Reinecke
2021-07-26  9:16                 ` Geert Uytterhoeven
2021-07-26  9:28                   ` Julia Lawall
2021-07-26  9:35                     ` Hannes Reinecke
2021-07-26 10:03                       ` Julia Lawall
2021-07-26 17:54                   ` James Bottomley
2021-07-26 18:16                     ` Linus Torvalds
2021-07-26 21:53                       ` NeilBrown
2021-07-26 18:31                     ` Laurent Pinchart
2021-07-26  9:17                 ` Dan Carpenter
2021-07-26  9:13             ` Dan Carpenter
2021-07-26 21:43         ` NeilBrown
2021-07-26  7:05   ` Dan Carpenter
2021-07-26 15:50 ` Paul E. McKenney
2021-07-27  9:38   ` Dan Carpenter
2021-07-27  9:50     ` Geert Uytterhoeven
2021-07-27 16:06     ` Paul E. McKenney

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