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Re: Intel's new rte_memcpy()
- From: Luke Gorrie <luke at snabb dot co>
- To: Luke Gorrie <luke at snabb dot co>, OndÅej BÃlka <neleai at seznam dot cz>, "H.J. Lu" <hjl dot tools at gmail dot com>, éå(åå) <ling dot ml at alibaba-inc dot com>, GNU C Library <libc-alpha at sourceware dot org>
- Date: Wed, 11 Mar 2015 14:15:27 +0100
- Subject: Re: Intel's new rte_memcpy()
- Authentication-results: sourceware.org; auth=none
- References: <CAA2XHbendDcfydewf2nrpPQkSsDWPdEH0SMsnqZAFsLF9q4Fzg at mail dot gmail dot com> <CAMe9rOpELuXQLvHQLLAeZitTTcz-xeg=ROoDm0dHe-fg4m-Jew at mail dot gmail dot com> <20150131184837 dot GA3539 at domone> <CAA2XHbcvDWjrshkdyo3++PnViOs5MdOC_+8qZoEb5UXJ21F1zA at mail dot gmail dot com> <20150305174741 dot GC6730 at vapier> <CAA2XHbfmbpjvqmJKbEASa86pwz-N-rB3noRmC9qrbuZeCwG7hQ at mail dot gmail dot com> <20150310152419 dot GV9455 at vapier>
On 10 March 2015 at 16:24, Mike Frysinger <email@example.com> wrote:
> just to be clear, the ABI change for memcpy was unrelated to the function
> signature. if you do hit a function that has a newer glibc symbol, it's
> usually because the function signature changed, and using the .symver
> redirect hack won't help you there.
Thanks for that heads-up. I will keep it in mind.
> getting an older distro is one way, but that's not what i said ... you can build
> a sep toolchain that uses an older glibc & gcc on a newer distro.
I'd like to avoid this for my particular application. The idea is that
people will download the source, make extensions, then build a release
and distribute it to their friends. The users are networking people
rather than professional programmers and I want to keep the "build my
first application" experience simple. (I'm probably in a similar boat
to the people creating build-your-own-stand-alone-video-game toolkits,
a bit away from the Linux/GNU mainstream :-))
> you should also note that gcc itself has symbol versioning with libgcc_s.so &
> libstdc++.so and you are tying yourself to that version when you link against
> them. depending on the target, libgcc_s.so might be pulled in implicitly.
Thanks for the tip. I'll treat these issues as bugs and add tests for
them if they come up. For now I have only sanity-tested by running
"myapp --help" inside docker containers of various distros to make
sure that it links and starts. I hope that automating this some fine
day will be a sufficient test for catching dependencies like this that