From: Rich Felker <dalias@libc.org>
To: musl@lists.openwall.com
Subject: Re: x86_64 and x32 fail to build
Date: Mon, 20 Apr 2015 21:35:25 -0400 [thread overview]
Message-ID: <20150421013525.GT6817@brightrain.aerifal.cx> (raw)
In-Reply-To: <alpine.LNX.2.11.1504210232480.2677@monopod.intra.ispras.ru>
On Tue, Apr 21, 2015 at 02:56:27AM +0300, Alexander Monakov wrote:
> > When building without --enable-warnings, there are many false positives from
> > -Wpointer-to-int-cast about x32 __scc(); at least from 4.5 onwards GCC enables
> > this warning by default, so perhaps if musl really wants to silence it, it
> > should test the corresponding -Wno-... flag outside of x$warnings == xyes
> > test?
>
> Could it be possible that implementation of __scc() can be adjusted to avoid
> triggering the warning? I hoped the following would achieve that:
>
> // Cast X to signed integral type of corresponding size
> #define __scc1(X) (__typeof__((X)-(__typeof__(1?(X):0))0)) (X)
> #define __scc(X) sizeof(1?(X):0ULL) < 8 ? (unsigned long) __scc1(X) : (long long) __scc1(X)
>
> .... but unfortunately it doesn't work with -Werror=pointer-arith when type of
> X is 'void *'.
Indeed, introducing invalid C to make a warning go away is not a nice
tradeoff.
Rich
next prev parent reply other threads:[~2015-04-21 1:35 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-04-20 19:21 Alexander Monakov
2015-04-20 21:13 ` Rich Felker
2015-04-20 21:30 ` Alexander Monakov
2015-04-20 22:00 ` Alexander Monakov
2015-04-20 23:56 ` Alexander Monakov
2015-04-21 1:35 ` Rich Felker [this message]
2015-04-21 7:30 ` Jens Gustedt
2015-04-21 8:56 ` Alexander Monakov
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