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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Thanks, I'm glad we don't necessarily have to upgrade OS to get upgraded compilers. I've never been too clear on these Unix sys-admin sorts of things.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><a name="_MailEndCompose"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">I'm happy this is going forward, I'm happy there is a plan, and I am *especially* happy that we have a reasonable amount of time to
get ready for it. If there's some place that someone is going to write down the general desire/policy for future advances in the minimum language standard used by the project, please make sure that statement includes reasonable advance notice to allow everyone
time to go through acquisition, validation, and deployment steps. Which has to include time for corporate procurement and IT engagement. I'd say 3 months is definitely a minimum lead time, and some contributors might need more.<o:p></o:p></span></a></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Are all the bot owners on board?<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">--paulr<o:p></o:p></span></p>
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<p class="MsoNormal"><b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> jfbastien@apple.com [mailto:jfbastien@apple.com]
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<b>Sent:</b> Friday, October 19, 2018 2:37 PM<br>
<b>To:</b> Robinson, Paul<br>
<b>Cc:</b> zturner@google.com; llvm-dev@lists.llvm.org<br>
<b>Subject:</b> Re: [llvm-dev] [cfe-dev] LLVM C++14/C++17 BoF - Summary<o:p></o:p></span></p>
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<p class="MsoNormal">On Oct 19, 2018, at 11:27 AM, via llvm-dev <<a href="mailto:llvm-dev@lists.llvm.org">llvm-dev@lists.llvm.org</a>> wrote:<o:p></o:p></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">So, there was agreement that the default gcc for recent-but-not-latest distros was not important? That is, it's okay to require people to upgrade their tools
in order to work with LLVM?</span><o:p></o:p></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">In my team's case, a lot of us are on Ubuntu 16.04 which comes with gcc 5.4, which is not gcc 7. And currently for Windows we're on MSVC 2015.</span><o:p></o:p></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">I suppose by March we can persuade our IT to upgrade all the people and bots to Ubuntu 18.04 (gcc 7.3?) and deploy MSVC 2017. But it's something we need to
plan for.</span><o:p></o:p></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">(I suppose I should thank the Google folks for being such slugs<span class="apple-converted-space"> </span></span><span style="font-size:11.0pt;font-family:Wingdings;color:#1F497D">J</span><span class="apple-converted-space"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"> </span></span><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">about
being ready to switch, because it will give us time to get things organized for ourselves.)</span><o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">The discussion from folks using Linux as well as from Linux vendors was that distros which come with older versions of GCC also provide easy ways to install newer versions of GCC, without upgrading the distro.<o:p></o:p></p>
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<p class="MsoNormal">There was little discussion of MSVC, besides praising its C++17 support in the latest version.<o:p></o:p></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">--paulr</span><o:p></o:p></p>
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<p class="MsoNormal"><b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span class="apple-converted-space"><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> </span></span><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">cfe-dev
[<a href="mailto:cfe-dev-bounces@lists.llvm.org"><span style="color:purple">mailto:cfe-dev-bounces@lists.llvm.org</span></a>]<span class="apple-converted-space"> </span><b>On Behalf Of<span class="apple-converted-space"> </span></b>Zachary Turner via cfe-dev<br>
<b>Sent:</b><span class="apple-converted-space"> </span>Friday, October 19, 2018 9:58 AM<br>
<b>To:</b><span class="apple-converted-space"> </span>llvm-dev; Clang Dev<br>
<b>Subject:</b><span class="apple-converted-space"> </span>[cfe-dev] LLVM C++14/C++17 BoF - Summary</span><o:p></o:p></p>
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<p class="MsoNormal">For those of you who were not able to attend the LLVM Developer Meeting (and as a recap for those who were), we had a productive BoF about enabling C++14 or C++17 in LLVM. The outcome of this can be generally summarized as:<o:p></o:p></p>
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<p class="MsoNormal">* There were no major objections to moving to C++14 / C++17 "as soon as possible"<o:p></o:p></p>
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<p class="MsoNormal">* "As soon as possible" is not immediately, but we are currently targeting March of 2019 due to some downstream contributors' needing to resolve some blockages before it can be possible.<o:p></o:p></p>
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<p class="MsoNormal">* There did not seem to be a strong sentiment that we should only move to C++14, so for the sake of this discussion we're assuming 17 unless someone presents a strong argument why 17 is *less* desirable than 14.<o:p></o:p></p>
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<p class="MsoNormal"> <o:p></o:p></p>
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<p class="MsoNormal">Minimum Compiler Versions for "Reasonable C++17 Support" (Mostly everything minus CTAD)<o:p></o:p></p>
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<p class="MsoNormal">GCC - Version 7 [1] (Version 8 for CTAD)<o:p></o:p></p>
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<p class="MsoNormal">Clang - Version 4 [2] (Version 5 for CTAD)<o:p></o:p></p>
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<p class="MsoNormal">MSVC - 2017 Update 5 [3] (Update 7 for CTAD)<o:p></o:p></p>
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<p class="MsoNormal"> <o:p></o:p></p>
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<p class="MsoNormal">We plan to add a CMake warning if your compiler version is below these versions soon. Around January, we will promote this to a CMake error which you must manually override by passing -DCMAKE_ALLLOW_DEPRECATED_COMPILER.<o:p></o:p></p>
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<p class="MsoNormal"> <o:p></o:p></p>
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<p class="MsoNormal">If I'm forgetting anything or misrepresenting anything that was said at the BoF please feel free to correct me.<o:p></o:p></p>
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<p class="MsoNormal"> <o:p></o:p></p>
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<p class="MsoNormal">[1] - <a href="https://www.gnu.org/software/gcc/projects/cxx-status.html"><span style="color:purple">https://www.gnu.org/software/gcc/projects/cxx-status.html</span></a><o:p></o:p></p>
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<p class="MsoNormal">[2] - <a href="https://clang.llvm.org/cxx_status.html"><span style="color:purple">https://clang.llvm.org/cxx_status.html</span></a><o:p></o:p></p>
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<p class="MsoNormal">[3] - <a href="https://docs.microsoft.com/en-us/cpp/visual-cpp-language-conformance?view=vs-2017"><span style="color:purple">https://docs.microsoft.com/en-us/cpp/visual-cpp-language-conformance?view=vs-2017</span></a><o:p></o:p></p>
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<p class="MsoNormal"><span style="font-size:9.0pt;font-family:"Helvetica","sans-serif"">_______________________________________________<br>
LLVM Developers mailing list<br>
</span><a href="mailto:llvm-dev@lists.llvm.org"><span style="font-size:9.0pt;font-family:"Helvetica","sans-serif";color:purple">llvm-dev@lists.llvm.org</span></a><span style="font-size:9.0pt;font-family:"Helvetica","sans-serif""><br>
</span><a href="http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev"><span style="font-size:9.0pt;font-family:"Helvetica","sans-serif";color:purple">http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev</span></a><o:p></o:p></p>
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