public inbox for gcc-bugs@sourceware.org
help / color / mirror / Atom feed
From: "matz at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug libstdc++/53646] Surprising effects of cxx11 vs cxx98 ABI compatibility
Date: Tue, 12 Jun 2012 15:36:00 -0000 [thread overview]
Message-ID: <bug-53646-4-9K81jZzLet@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-53646-4@http.gcc.gnu.org/bugzilla/>
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53646
--- Comment #5 from Michael Matz <matz at gcc dot gnu.org> 2012-06-12 15:36:01 UTC ---
(In reply to comment #2)
> N.B. std::pair is not a POD in c++98 or c++11, so I don't know what libstdc++
> could have done to cause the FE to change how it returns a std::pair.
I don't know if it's PODness (but I believe that it is), but the calling
convention is changed by the existence of this c++11 construct in std::pair:
pair(pair&& __p)
noexcept(__and_<is_nothrow_move_constructible<_T1>,
is_nothrow_move_constructible<_T2>>::value)
: first(std::forward<first_type>(__p.first)),
second(std::forward<second_type>(__p.second)) { }
It's some sort of copy-ctor, right? In any case when it's there (and it's
only there when compiling/preprocessing in c++11 mode), then the frontend
makes this type be TREE_ADDRESSABLE, aggregate_value_p will return true,
and that makes the ABI use an invisible reference.
next prev parent reply other threads:[~2012-06-12 15:36 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-06-12 13:18 [Bug c++/53646] New: " matz at gcc dot gnu.org
2012-06-12 13:38 ` [Bug libstdc++/53646] " redi at gcc dot gnu.org
2012-06-12 14:19 ` redi at gcc dot gnu.org
2012-06-12 14:28 ` redi at gcc dot gnu.org
2012-06-12 14:29 ` redi at gcc dot gnu.org
2012-06-12 15:36 ` matz at gcc dot gnu.org [this message]
2012-06-12 15:42 ` matz at gcc dot gnu.org
2012-06-12 15:50 ` redi at gcc dot gnu.org
2012-06-12 15:53 ` redi at gcc dot gnu.org
2012-06-12 15:57 ` redi at gcc dot gnu.org
2012-06-12 16:02 ` matz at gcc dot gnu.org
2012-06-12 16:05 ` paolo.carlini at oracle dot com
2012-06-12 16:13 ` paolo.carlini at oracle dot com
2012-06-13 9:39 ` paolo.carlini at oracle dot com
2012-06-13 10:23 ` redi at gcc dot gnu.org
2012-06-13 12:08 ` matz at gcc dot gnu.org
2012-06-13 14:55 ` [Bug c++/53646] " redi at gcc dot gnu.org
2012-06-14 6:33 ` jason at gcc dot gnu.org
2012-06-21 14:37 ` matz at gcc dot gnu.org
2012-06-21 14:47 ` redi at gcc dot gnu.org
2012-06-21 15:26 ` matz at gcc dot gnu.org
2012-06-21 15:33 ` matz at gcc dot gnu.org
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=bug-53646-4-9K81jZzLet@http.gcc.gnu.org/bugzilla/ \
--to=gcc-bugzilla@gcc.gnu.org \
--cc=gcc-bugs@gcc.gnu.org \
/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).