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Re: Possible unsafe use of strncat in sbin/sysctl/sysctl.c

On 2011-08-24 00:22, Marc Balmer wrote:
Am 24.08.11 00:08, schrieb Joerg Sonnenberger:
On Tue, Aug 23, 2011 at 09:58:53PM +0000, David Holland wrote:
On Tue, Aug 23, 2011 at 11:52:11PM +0200, Marc Balmer wrote:
  >  (void)wait!  That was a pure personal remark.  I really don't know where
  >  that (void)bla idiom comes from, and I obviously don't (void)like it.

It's an artifact of our stupid lint(1).

Not really, it is used by other analyzers to mean "yes, I know this
returns something, but I don't care". The major exception of course is
that GCC broke it for the attributed usage -- half of the pain of
dealing with modern glibc in this regard.

But that is kind of, well, unneeded.  A compiler can detect that I don't
use the return value by seeing that I don't use the return value.

Why tell the compiler that I don't want to use the return value?  It's a
stupid rule, to say the least.

How do you distinguish between:

"I ignore the return value of this function. I know this, I'm prefectly happy with that, and it is intentional."


"I forgot to check the return value."


Both cases mean I don't use the return value. But in one case, this is ok, while in the other, it's a bug. Do your compiler know something I don't?


Next thing will be adding a (really) and (maybe) statement to functions
which we really or maybe want to execute, and maybe (never) for
functions that we never call:

int (really)
main(int argc, char *argc[])

int (maybe)

void (never)
        /* NOTREACHED */

Johnny Billquist                  || "I'm on a bus
                                  ||  on a psychedelic trip
email:             ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol

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