<html><head><style type='text/css'>p { margin: 0; }</style></head><body><div style='font-family: arial,helvetica,sans-serif; font-size: 10pt; color: #000000'>This makes sense to me. Especially since, in practice, we've already done it ;)<br><br> -Hal<br><br><hr id="zwchr"><blockquote style="border-left: 2px solid rgb(16, 16, 255); margin-left: 5px; padding-left: 5px; color: rgb(0, 0, 0); font-weight: normal; font-style: normal; text-decoration: none; font-family: Helvetica,Arial,sans-serif; font-size: 12pt;"><b>From: </b>"Reid Kleckner via llvm-dev" <llvm-dev@lists.llvm.org><br><b>To: </b>"Teresa Johnson" <tejohnson@google.com><br><b>Cc: </b>"llvm-dev" <llvm-dev@lists.llvm.org><br><b>Sent: </b>Wednesday, October 12, 2016 6:05:39 PM<br><b>Subject: </b>Re: [llvm-dev] [RFC] Increase minimum supported GCC version for building LLVM to 4.8<br><br><div dir="ltr">+1. I've been bitten by the 4.7 STL's lack of std::map::emplace a few times, so I support this.</div><div class="gmail_extra"><br><div class="gmail_quote">On Wed, Oct 12, 2016 at 3:51 PM, Teresa Johnson via llvm-dev <span dir="ltr"><<a href="mailto:llvm-dev@lists.llvm.org" target="_blank">llvm-dev@lists.llvm.org</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;"><div dir="ltr">According to the documentation at <a href="http://llvm.org/docs/GettingStarted.html#software" target="_blank">http://llvm.org/docs/GettingStarted.html#software</a>, compiling LLVM with GCC requires at least version 4.7.0. However, there are apparently several problems building current LLVM/Clang with gcc 4.7.X. This proposal is to increase the minimum required GCC to 4.8.<div><br></div><div>This is split off of the thread started here:</div><div> <a href="http://lists.llvm.org/pipermail/llvm-dev/2016-October/105742.html" target="_blank">http://lists.llvm.org/pipermail/llvm-dev/2016-October/105742.html</a></div><div>which is a fairly recent regression in being able to compile LTO.cpp with GCC 4.7.4, which I tracked down to a known GCC bug.<br></div><div><br></div><div>According to James Knight, it is not the only place where GCC 4.7.X cannot compile the clang toolchain, which apparently hasn't been buildable by GCC 4.7.X in >3 months:</div><div> <a href="http://lists.llvm.org/pipermail/llvm-dev/2016-October/105825.html" target="_blank">http://lists.llvm.org/pipermail/llvm-dev/2016-October/105825.html</a></div><div><br></div><div>Renato also suggests bumping the minimum to 4.8, as that is the oldest shipped version in most stable Linux distributions:</div><div> <a href="http://lists.llvm.org/pipermail/llvm-dev/2016-October/105826.html" target="_blank">http://lists.llvm.org/pipermail/llvm-dev/2016-October/105826.html</a></div><div><br></div><div>We currently have many buildbots building with GCC 4.8, but none with GCC 4.7.X, which is why this issue was not discovered previously.</div><div><br></div><div>Thoughts?</div><div><br></div><div>Thanks,</div><div>Teresa</div><span class="HOEnZb"><font color="#888888"><div><div><br></div>-- <br><div class="m_-4327606693312860139gmail_signature"><span style="font-family: times; font-size: medium;"><table cellpadding="0" cellspacing="0"><tbody><tr style="color: rgb(85, 85, 85); font-family: sans-serif; font-size: small;"><td style="border-top: 2px solid rgb(213, 15, 37);" nowrap="nowrap">Teresa Johnson |</td><td style="border-top: 2px solid rgb(51, 105, 232);" nowrap="nowrap"> Software Engineer |</td><td style="border-top: 2px solid rgb(0, 153, 57);" nowrap="nowrap"> <a href="mailto:tejohnson@google.com" target="_blank">tejohnson@google.com</a> |</td><td style="border-top: 2px solid rgb(238, 178, 17);" nowrap="nowrap"> <a href="tel:408-460-2413" target="_blank">408-460-2413</a></td></tr></tbody></table></span></div>
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<br>_______________________________________________<br>LLVM Developers mailing list<br>llvm-dev@lists.llvm.org<br>http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev<br></blockquote><br><br><br>-- <br><div><span name="x"></span>Hal Finkel<br>Lead, Compiler Technology and Programming Languages<br>Leadership Computing Facility<br>Argonne National Laboratory<span name="x"></span><br></div></div></body></html>