From: Richard Henderson <rth@twiddle.net>
To: Carlos O'Donell <carlos@systemhalted.org>
Cc: Thomas Schwinge <thomas@codesourcery.com>,
libc-alpha@sourceware.org, libc-ports@sourceware.org
Subject: Re: Usage of __attribute__used__ in (system) headers?
Date: Mon, 18 Feb 2013 19:21:00 -0000 [thread overview]
Message-ID: <51227F2E.5060103@twiddle.net> (raw)
In-Reply-To: <CAE2sS1hXkxSq_sr=ySEeaV99O5WOAmaygufmeGmwMuc2d+EnZw@mail.gmail.com>
On 02/18/2013 11:00 AM, Carlos O'Donell wrote:
>> > static union { unsigned char __c[4]; float __d; } __nan_union
>> > - __attribute_used__ = { __nan_bytes };
>> > + = { __nan_bytes };
>> > # define NAN (__nan_union.__d)
>> >
>> > #endif /* GCC. */
> I disagree, it's useful to mark the non-GCC version with
> an __attribute_used__ such that in the future we might
> use another compiler without problems.
The annotation should not be attribute used at all, but rather unused.
Used says that the object is referenced in some non-visible way by
assembly, and thus cannot be elided. Unused says that we understand the
variable may not be referenced, and don't warn; but do, in particular,
remove it if it is unused.
As for whether or not to annotate for non-GCC... I'm ok with either.
r~
next prev parent reply other threads:[~2013-02-18 19:21 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <87r4khnbqm.fsf@kepler.schwinge.homeip.net>
2013-02-18 19:00 ` Carlos O'Donell
2013-02-18 19:21 ` Richard Henderson [this message]
2013-02-18 19:41 ` Carlos O'Donell
2013-02-20 16:06 ` Thomas Schwinge
2013-02-20 16:25 ` Carlos O'Donell
2013-02-20 17:56 ` Thomas Schwinge
2013-02-20 18:02 ` Carlos O'Donell
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=51227F2E.5060103@twiddle.net \
--to=rth@twiddle.net \
--cc=carlos@systemhalted.org \
--cc=libc-alpha@sourceware.org \
--cc=libc-ports@sourceware.org \
--cc=thomas@codesourcery.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).