Date: Sat, 03 May 2003 08:29:58 -0400 From: "Louis A. Mamakos" <louie@TransSys.COM> To: "Jacques A. Vidrine" <nectar@freebsd.org> Cc: Dag-Erling Smorgrav <des@ofug.org> Subject: Re: incorrect enum warning? Message-ID: <200305031229.h43CTw1L067503@whizzo.transsys.com> In-Reply-To: Your message of "Thu, 01 May 2003 10:07:13 CDT." <20030501150713.GA34992@madman.celabo.org> References: <xzp7k9a67pf.fsf@flood.ping.uio.no> <20030501150713.GA34992@madman.celabo.org>
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> On Thu, May 01, 2003 at 04:51:40PM +0200, Dag-Erling Smorgrav wrote:
> > Why does the following code in OpenPAM headers:
> >
> > /*
> > * XSSO 5.4
> > */
> > enum {
> > PAM_SILENT = 0x80000000,
> > PAM_DISALLOW_NULL_AUTHTOK = 0x1,
> > PAM_ESTABLISH_CRED = 0x1,
> > PAM_DELETE_CRED = 0x2,
> > PAM_REINITIALIZE_CRED = 0x4,
> > PAM_REFRESH_CRED = 0x8,
> > PAM_PRELIM_CHECK = 0x1,
> > PAM_UPDATE_AUTHTOK = 0x2,
> > PAM_CHANGE_EXPIRED_AUTHTOK = 0x4
> > };
> >
> > cause the following warning when compiled with CSTD=c99:
> >
> > /usr/src/contrib/openpam/include/security/pam_constants.h:100: warning: ISO C restricts enumerator values to range of `int'
> >
> > when 0x80000000 is clearly within the range of 'int' on all platforms
> > we support?
>
> Guessing:
> C does not specify one's complement or two's complement representation
> of integers. On a one's complement 32-bit platform, 0x80000000 is -0
> (negative zero), which cannot be an `int'.
That's incorrect; on a 32-bit 1's complement CPU, 0xffffffff is -0. You're
thinking of the signed magnitude representation.
louie
>
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