From: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>
To: Alessandro Rubini <rubini-list@gnudd.com>
Cc: barebox@lists.infradead.org, embedded24@evers-fischer.de
Subject: Re: [PATCH] automount: check for recursive automount
Date: Thu, 3 Jul 2014 11:33:21 +0200 [thread overview]
Message-ID: <20140703093321.GU14781@pengutronix.de> (raw)
In-Reply-To: <20140703090045.GA21384@mail.gnudd.com>
On Thu, Jul 03, 2014 at 11:00:45AM +0200, Alessandro Rubini wrote:
> > static variables are initialized to 0 (for pointers: NULL) by the
> > compiler.
>
> Well, not really. The compiler just places them in the .bss area. It
> is barebox, it is run-time initialization, that zeroes bss.
>
> So it is barebox, not the compiler.
Yeah, in general it's even worse because there might be platforms where
NULL isn't represented by a literal 0. (Not sure if something like this
exists, but it's allowed by the standard.)
C99 tells us:
If an object that has automatic storage duration is not initialized explicitly,
its value is indeterminate. If an object that has static storage duration is
not initialized explicitly, then:
- if it has pointer type, it is initialized to a null pointer;
- if it has arithmetic type, it is initialized to (positive or unsigned) zero;
- if it is an aggregate, every member is initialized (recursively) according to
these rules;
- if it is a union, the first named member is initialized (recursively)
according to these rules.
I assume it's included in earlier standards, too, but I don't have these
handy.
Best regards
Uwe
--
Pengutronix e.K. | Uwe Kleine-König |
Industrial Linux Solutions | http://www.pengutronix.de/ |
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next prev parent reply other threads:[~2014-07-03 9:33 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-07-03 8:34 Rolf Evers-Fischer
2014-07-03 8:51 ` Uwe Kleine-König
2014-07-03 9:00 ` Alessandro Rubini
2014-07-03 9:33 ` Uwe Kleine-König [this message]
2014-07-03 11:05 ` Rolf Evers-Fischer
-- strict thread matches above, loose matches on Subject: below --
2014-07-03 6:21 Sascha Hauer
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