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From: "rguenth at gcc dot gnu dot org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c/42884] GCC (v4.3.3) fails to detect uninitialized variable
Date: Wed, 27 Jan 2010 16:51:00 -0000 [thread overview]
Message-ID: <20100127165108.21490.qmail@sourceware.org> (raw)
In-Reply-To: <bug-42884-18720@http.gcc.gnu.org/bugzilla/>
------- Comment #16 from rguenth at gcc dot gnu dot org 2010-01-27 16:51 -------
(In reply to comment #15)
> (In reply to comment #14)
> > As diglen has its address taken and we do not warn about uninitialized use
> > of memory we do not warn.
> >
>
> I get that the compiler can't track if an external function actually
> initializes a value through a pointer, but the "diglen = sizeof..." line should
> be good enough for the positive case. In the false path though "diglen" is not
> initialized nor its address taken.
No, it's an implementation detail. Uninitialized variable use tracking
works with detecting uses of SSA name default definitions. Memory
is not in SSA form so this mechanism does not work.
Uninitialized memory detection is not done at all.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42884
next prev parent reply other threads:[~2010-01-27 16:51 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-01-27 13:58 [Bug c/42884] New: " tstdenis at elliptictech dot com
2010-01-27 14:01 ` [Bug c/42884] " paolo dot carlini at oracle dot com
2010-01-27 14:01 ` paolo dot carlini at oracle dot com
2010-01-27 14:01 ` tstdenis at elliptictech dot com
2010-01-27 14:03 ` tstdenis at elliptictech dot com
2010-01-27 14:07 ` paolo dot carlini at oracle dot com
2010-01-27 14:07 ` paolo dot carlini at oracle dot com
2010-01-27 14:09 ` tstdenis at elliptictech dot com
2010-01-27 14:13 ` paolo dot carlini at oracle dot com
2010-01-27 14:28 ` tstdenis at elliptictech dot com
2010-01-27 14:37 ` paolo dot carlini at oracle dot com
2010-01-27 15:43 ` tstdenis at elliptictech dot com
2010-01-27 15:47 ` paolo dot carlini at oracle dot com
2010-01-27 15:58 ` tstdenis at elliptictech dot com
2010-01-27 15:59 ` paolo dot carlini at oracle dot com
2010-01-27 16:05 ` tstdenis at elliptictech dot com
2010-01-27 16:06 ` rguenth at gcc dot gnu dot org
2010-01-27 16:22 ` tstdenis at elliptictech dot com
2010-01-27 16:23 ` paolo dot carlini at oracle dot com
2010-01-27 16:51 ` rguenth at gcc dot gnu dot org [this message]
2010-01-27 17:55 ` tstdenis at elliptictech dot com
2010-01-27 19:51 ` rguenth at gcc dot gnu dot org
2010-09-02 16:01 ` tadhunt at gmail dot com
2010-09-02 23:11 ` manu at gcc dot gnu dot org
2010-09-03 13:08 ` thutt at vmware dot com
2010-09-03 14:07 ` manu at gcc dot gnu dot org
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