From: prj@po.cwru.edu (Paul Jarc)
To: Joe Buck <Joe.Buck@synopsys.COM>
Cc: Nick Ing-Simmons <nick@ing-simmons.net>,
jamie@shareable.org, gcc@gcc.gnu.org,
"'Morten Welinder'" <terra@gnome.org>, Dave Korn <dk@artimi.com>
Subject: Re: signed vs unsigned pointer warning
Date: Fri, 08 Oct 2004 19:57:00 -0000 [thread overview]
Message-ID: <m3mzyxgkil.fsf@multivac.cwru.edu> (raw)
In-Reply-To: <20041008100853.A2207@synopsys.com> (Joe Buck's message of "Fri, 8 Oct 2004 10:08:53 -0700")
Joe Buck <Joe.Buck@synopsys.COM> wrote:
> No, (unsigned)-1 does not turn into 255, it turns into a very large
> number.
But character 255, as a signed char, is also -1, and so will also
become the same large number. The caller must cast char to unsigned
char to ensure that EOF is distinct. *Only* the caller can make the
distinction reliably, since only the caller knows whether this
particular -1 is supposed to be EOF.
paul
next prev parent reply other threads:[~2004-10-08 17:59 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-09-22 16:43 Morten Welinder
2004-09-22 17:17 ` Paul Koning
2004-09-22 17:27 ` Morten Welinder
2004-09-22 17:49 ` Dave Korn
2004-09-22 17:20 ` Dave Korn
2004-09-23 1:31 ` Andreas Schwab
2004-09-23 12:29 ` Dave Korn
2004-09-23 18:57 ` Joe Buck
2004-09-23 19:38 ` Dave Korn
2004-09-27 2:04 ` Jamie Lokier
2004-10-08 13:29 ` Nick Ing-Simmons
2004-10-08 13:32 ` Dave Korn
2004-10-08 17:20 ` Joe Buck
2004-10-08 17:28 ` Paul Jarc
2004-10-08 17:59 ` Joe Buck
2004-10-08 18:15 ` Dave Korn
2004-10-08 18:22 ` Joe Buck
2004-10-08 18:24 ` Jamie Lokier
2004-10-08 19:57 ` Paul Jarc [this message]
2004-10-09 7:05 ` Jamie Lokier
2004-10-09 8:48 ` Paul Jarc
2004-10-11 16:34 ` Richard Earnshaw
2004-10-08 18:57 ` Morten Welinder
2004-10-08 20:59 ` Matthias B.
2004-10-08 22:34 ` Paul Koning
2004-10-10 2:03 ` Matthias B.
2004-10-09 1:39 ` Andreas Schwab
2004-10-11 0:11 ` Kai Henningsen
-- strict thread matches above, loose matches on Subject: below --
2004-09-21 20:52 Richard Henderson
2004-09-21 22:36 ` Linus Torvalds
2004-09-22 14:35 ` Dave Korn
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