Gentoo Archives: gentoo-dev

From: Mike Frysinger <vapier@g.o>
To: gentoo-dev@l.g.o
Subject: Re: [gentoo-dev] gcc-5 news item wrt C++ ABI
Date: Tue, 20 Oct 2015 18:18:04
Message-Id: 20151020181746.GH3918@vapier.lan
In Reply to: Re: [gentoo-dev] gcc-5 news item wrt C++ ABI by "Anthony G. Basile"
1 On 03 Oct 2015 19:53, Anthony G. Basile wrote:
2 > On 10/3/15 7:16 PM, hasufell wrote:
3 > > On 10/03/2015 04:13 AM, Mike Frysinger wrote:
4 > >> Title: GCC 5 Defaults to the New C++11 ABI
5 > >> Author: Mike Frysinger <vapier@g.o>
6 > >> Content-Type: text/plain
7 > >> Posted: 2015-10-02
8 > >> Revision: 1
9 > >> News-Item-Format: 1.0
10 > >> Display-If-Installed: >=sys-devel/gcc-5
11 > >>
12 > >> GCC 5 uses the new C++ ABI by default. When building new code, you might run
13 > >> into link time errors like:
14 > >> ...: undefined reference to '_ZNSt6chrono12steady_clock3nowEv@GLIBCXX_3.4.17'
15 > >> Or you might see linkage failures with "std::__cxx11::string" in the output.
16 > >>
17 > >> These are signs that you need to rebuild packages using the new C++ ABI.
18 > >> You can quickly do so by using revdep-rebuild like so:
19 > >> # revdep-rebuild --library 'libstdc\+\+\.so\.6'
20 > >>
21 > > We shouldn't assume a particular PM/toolset in news items, IMO. Just
22 > > saying that people might have to rebuild packages linked against
23 > > libstdc++.so.6 should be enough.
24 > >
25 > > They can read the docs if they don't know how.
26 >
27 > Nothing precludes adding "see .... if you use paludis or clang."
28 > However, I'd like to see the above in there.
29
30 what is the alternative suggestion for paludis ?
31
32 wrt clang, i thought we were using gcc's libstdc++ and not the libc++ project.
33 if people are using libc++ & clang, then this news entry does not change ...
34 you'd still need to rebuild anything using libstdc++. that said, i'm not sure
35 libc++ & clang builds are common enough to warrant mentioning here.
36 -mike

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