[llvm-dev] [RFC] migrating past C++11

Thu Feb 7 10:28:32 PST 2019

Indeed this has finally stuck, with just clang-with-lto-ubuntu broken at the moment. I’m inclined to leave it checked in, and try to get it into the LLVM 8 branch as well.

> On Feb 7, 2019, at 9:18 AM, paul.robinson at sony.com wrote:
> 
> It seems the CMake changes have landed; but the docs are still a bit out of date?
> CMake.html talks about LLVM_FORCE_USE_OLD_TOOLCHAIN but not LLVM_TEMPORARILY_ALLOW_OLD_TOOLCHAIN.

I’m. Not sure how one updates the website’s docs, I had assumed the RST files would automatically get rebuilt and pushed? Agreed we want it fixed, but I don’t think it’s good reason to revert since the error message is pretty clear.

> Also, it looks like LLVM_TEMPORARILY_ALLOW_OLD_TOOLCHAIN is not propagated down to the NATIVE configuration when you set LLVM_OPTIMIZED_TABLEGEN.  If that's going to be a permanent deficiency, it should be mentioned in the docs as well.

Someone mentioned MSVC was having issues that way? https://reviews.llvm.org/rL353374#624722 <https://reviews.llvm.org/rL353374#624722>
That seems like general badness in the way that configuration is set up, no? It should probably get fixed separately.

> Thanks,
> --paulr
>   <>
> From: llvm-dev [mailto:llvm-dev-bounces at lists.llvm.org] On Behalf Of JF Bastien via llvm-dev
> Sent: Saturday, February 02, 2019 1:04 AM
> To: via llvm-dev
> Subject: Re: [llvm-dev] [RFC] migrating past C++11
>  
> After a few attempts I think we’re in sight of success: we only have the two following bots remaining with old versions of libstdc++ and new versions of clang:
>  
> polly-amd64-linux
> polly-arm-linux
>  
> Once fixed the toolchain bump should stick.
> 
> 
> On Jan 31, 2019, at 2:07 PM, JF Bastien via llvm-dev <llvm-dev at lists.llvm.org <mailto:llvm-dev at lists.llvm.org>> wrote:
>  
> 
> 
> 
> On Jan 31, 2019, at 2:03 PM, Alex Bradbury <asb at asbradbury.org <mailto:asb at asbradbury.org>> wrote:
>  
> On Tue, 29 Jan 2019 at 21:05, JF Bastien via llvm-dev
> <llvm-dev at lists.llvm.org <mailto:llvm-dev at lists.llvm.org>> wrote:
> 
> 
> The patch is about ready to land, which means any older compiler will soft-error (which you can turn off with LLVM_TEMPORARILY_ALLOW_OLD_TOOLCHAIN). I think we should then cherry-pick the patch to the LLVM 8 branch.
> 
> The last remaining issue are the buildbots. I audited *all* bots in http://lab.llvm.org:8011/buildslaves <http://lab.llvm.org:8011/buildslaves> (there's so many!). Some of them are down, I therefore have no idea what they run. Here are the bots that will definitely break, with their maintainers:
> 
> Galina Kistanova <gkistanova at gmail.com <mailto:gkistanova at gmail.com>>
> am1i-slv1 -- gcc (Ubuntu 4.8.4-2ubuntu1~14.04.3) 4.8.4
> as-bldslv4 -- Microsoft (R) Visual Studio (R) 2015 (14.0)
> ps4-buildslave2 -- Microsoft (R) Visual Studio (R) 2015 (14.0)
> 
> Hexagon QA <llvm.buildmaster at quicinc.com <mailto:llvm.buildmaster at quicinc.com>>
> hexagon-build-02 -- gcc (Ubuntu 4.9.2-10ubuntu13) 4.9.2
> hexagon-build-03 -- gcc (Ubuntu 4.9.2-10ubuntu13) 4.9.2
> 
> Vitaly Buka <vitalybuka at google.com <mailto:vitalybuka at google.com>>
> sanitizer-buildbot6 -- gcc (Ubuntu 4.8.4-2ubuntu1~14.04.3) 4.8.4
> 
> Reid Kleckner <rnk at google.com <mailto:rnk at google.com>>
> sanitizer-windows -- Microsoft (R) Visual Studio (R) 2015 (14.0)
> 
> Ilia Taraban <mstester.llvm at gmail.com <mailto:mstester.llvm at gmail.com>>
> windows7-buildbot -- Microsoft (R) Visual Studio (R) 2015 (14.0)
> 
> 
> The maintainers have 3 options:
> 
> 1. Pass LLVM_TEMPORARILY_ALLOW_OLD_TOOLCHAIN to their bot, suffer breakage later.
> 2. Update the bot to a newer compiler version.
> 3. Entirely turn down the bot.
> 
> I’ve emailed the maintainers and some have already responded. Once all bots are in a good state I’ll commit the patch (unless someone else chimes in with new information).
> 
> Did anyone pick option 1)? If I understand correctly, we probably want
> to ensure that at least some bots do this, so we can ensure an old
> compiler + LLVM_TEMPORARILY_ALLOW_OLD_TOOLCHAIN build actually remains
> functional up until the point support for the old compiler is actually
> removed.
>  
> Reid asked me to do so for sanitizer-windows:
> https://reviews.llvm.org/D57525 <https://reviews.llvm.org/D57525>
>  
> Ideally yes we’d have bots covering all eventualities, but this is but one of many holes in our coverage. On the upside, that hole is disappearing in a few months :)
>  
> 
> 
> Best,
> 
> Alex
> 
> _______________________________________________
> LLVM Developers mailing list
> llvm-dev at lists.llvm.org <mailto:llvm-dev at lists.llvm.org>
> https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev <https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20190207/2be24bec/attachment-0001.html>