public inbox for gcc@gcc.gnu.org
 help / color / mirror / Atom feed
From: Alex Colomar <alx.manpages@gmail.com>
To: Jakub Jelinek <jakub@redhat.com>
Cc: "Stefan Puiu" <stefan.puiu@gmail.com>,
	"GNU C Library" <libc-alpha@sourceware.org>,
	linux-man <linux-man@vger.kernel.org>,
	gcc@gcc.gnu.org, "Igor Sysoev" <igor@sysoev.ru>,
	"Bastien Roucariès" <rouca@debian.org>
Subject: Re: struct sockaddr_storage
Date: Tue, 24 Jan 2023 17:40:32 +0100	[thread overview]
Message-ID: <34c803d2-d994-63cf-2a49-f57f9c0eb6fe@gmail.com> (raw)
In-Reply-To: <Y8633MfNxeI9StbW@tucnak>


[-- Attachment #1.1: Type: text/plain, Size: 938 bytes --]

Hi Jakub,

On 1/23/23 17:37, Jakub Jelinek wrote:
> Please see transparent_union documentation in GCC documentation.
> E.g. https://gcc.gnu.org/onlinedocs/gcc-12.2.0/gcc/Common-Type-Attributes.html#index-transparent_005funion-type-attribute
> transparent_union doesn't change anything regarding type punning, it is
> solely about function arguments, how arguments of that type are passed
> (as first union member) and that no casts to the union are needed from
> the member types.

Yep, when I wrote that I didn't fully understand it.  Now I got it. 
I'll prepare some better suggestion about a fix.

Thanks.

> And, with LTO TU boundaries are lost, inlining or other IPA optimizations
> (including say modref) work in between TUs.

Yeah, that's why we need a fix.  Compilers will only get better at 
optimizing, so UB will sooner or later be a problem.

Cheers,

Alex

-- 
<http://www.alejandro-colomar.es/>


[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 833 bytes --]

  reply	other threads:[~2023-01-24 16:40 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-01-19 14:11 Alejandro Colomar
2023-01-20 10:06 ` Stefan Puiu
2023-01-20 12:39   ` Alejandro Colomar
2023-01-23  7:40     ` Stefan Puiu
2023-01-23 16:03       ` Alejandro Colomar
2023-01-23 16:28         ` Richard Biener
2023-01-24 16:38           ` Alex Colomar
2023-01-23 16:37         ` Jakub Jelinek
2023-01-24 16:40           ` Alex Colomar [this message]
2023-01-24 18:00           ` Alex Colomar
2023-01-24 11:16   ` Rich Felker
2023-01-24 16:53     ` Alex Colomar

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=34c803d2-d994-63cf-2a49-f57f9c0eb6fe@gmail.com \
    --to=alx.manpages@gmail.com \
    --cc=gcc@gcc.gnu.org \
    --cc=igor@sysoev.ru \
    --cc=jakub@redhat.com \
    --cc=libc-alpha@sourceware.org \
    --cc=linux-man@vger.kernel.org \
    --cc=rouca@debian.org \
    --cc=stefan.puiu@gmail.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).