From: Jeff King <peff@peff.net>
To: Andreas Schwab <schwab@linux-m68k.org>
Cc: "Ævar Arnfjörð Bjarmason" <avarab@gmail.com>,
git@vger.kernel.org, "Junio C Hamano" <gitster@pobox.com>,
"Jim Meyering" <jim@meyering.net>,
"Fredrik Gustafsson" <iveqy@iveqy.com>
Subject: Re: [PATCH 3/3] grep: get rid of useless x < 0 comparison on an enum member
Date: Mon, 7 Nov 2011 13:55:36 -0500 [thread overview]
Message-ID: <20111107185536.GA5450@sigill.intra.peff.net> (raw)
In-Reply-To: <20111107183402.GA5118@sigill.intra.peff.net>
On Mon, Nov 07, 2011 at 01:34:02PM -0500, Jeff King wrote:
> > The whole point of the statement is a sanity check to uncover bugs. If
> > you remove the first condition you completely ruin its point.
> [...]
> Yes, static analysis can miss some bugs (like passing the address of the
> enum through a void pointer (e.g., when memset'ing a struct)). But
> couldn't it just as easily be out of range in the other direction?
Oops, I just looked at the actual conditional, and it is indeed
range-checking the whole enum. So if you are going to do that at all,
then yes, checking both sides is sensible, and that is what the original
conditional does. Sorry for my confusion.
I do still question the value of the check at all, though, given that
static analysis can find those bugs.
-Peff
next prev parent reply other threads:[~2011-11-07 18:55 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-11-06 12:06 [PATCH 0/3] Fix code issues spotted by clang Ævar Arnfjörð Bjarmason
2011-11-06 12:06 ` [PATCH 1/3] apply: get rid of useless x < 0 comparison on a size_t type Ævar Arnfjörð Bjarmason
2011-11-06 18:35 ` Junio C Hamano
2011-11-07 19:09 ` Giuseppe Bilotta
2011-11-06 12:06 ` [PATCH 2/3] diff/apply: cast variable in call to free() Ævar Arnfjörð Bjarmason
2011-11-06 12:06 ` [PATCH 3/3] grep: get rid of useless x < 0 comparison on an enum member Ævar Arnfjörð Bjarmason
2011-11-06 15:03 ` Andreas Schwab
2011-11-07 12:42 ` Ævar Arnfjörð Bjarmason
2011-11-07 13:12 ` Andreas Schwab
2011-11-07 16:38 ` Jeff King
2011-11-07 18:24 ` Andreas Schwab
2011-11-07 18:34 ` Jeff King
2011-11-07 18:55 ` Jeff King [this message]
2011-11-07 19:06 ` Ævar Arnfjörð Bjarmason
2011-11-07 20:13 ` Andreas Schwab
2011-11-07 19:49 ` Jonathan Nieder
2011-11-07 21:18 ` Junio C Hamano
2011-11-07 21:32 ` Jonathan Nieder
2011-11-07 21:48 ` Junio C Hamano
2011-11-07 22:21 ` Jonathan Nieder
2011-11-06 12:33 ` [PATCH 0/3] Fix code issues spotted by clang Ævar Arnfjörð Bjarmason
2011-11-08 16:05 ` Elijah Newren
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