Teresa Johnson via llvm-dev
2016-Oct-12 22:51 UTC
[llvm-dev] [RFC] Increase minimum supported GCC version for building LLVM to 4.8
According to the documentation at http://llvm.org/docs/GettingStarted.html#software, 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. This is split off of the thread started here: http://lists.llvm.org/pipermail/llvm-dev/2016-October/105742.html 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. 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: http://lists.llvm.org/pipermail/llvm-dev/2016-October/105825.html Renato also suggests bumping the minimum to 4.8, as that is the oldest shipped version in most stable Linux distributions: http://lists.llvm.org/pipermail/llvm-dev/2016-October/105826.html 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. Thoughts? Thanks, Teresa -- Teresa Johnson | Software Engineer | tejohnson at google.com | 408-460-2413 -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20161012/bf735024/attachment.html>
Reid Kleckner via llvm-dev
2016-Oct-12 23:05 UTC
[llvm-dev] [RFC] Increase minimum supported GCC version for building LLVM to 4.8
+1. I've been bitten by the 4.7 STL's lack of std::map::emplace a few times, so I support this. On Wed, Oct 12, 2016 at 3:51 PM, Teresa Johnson via llvm-dev < llvm-dev at lists.llvm.org> wrote:> According to the documentation at http://llvm.org/docs/ > GettingStarted.html#software, 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. > > This is split off of the thread started here: > http://lists.llvm.org/pipermail/llvm-dev/2016-October/105742.html > 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. > > 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: > http://lists.llvm.org/pipermail/llvm-dev/2016-October/105825.html > > Renato also suggests bumping the minimum to 4.8, as that is the oldest > shipped version in most stable Linux distributions: > http://lists.llvm.org/pipermail/llvm-dev/2016-October/105826.html > > 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. > > Thoughts? > > Thanks, > Teresa > > -- > Teresa Johnson | Software Engineer | tejohnson at google.com | > 408-460-2413 > > _______________________________________________ > LLVM Developers mailing list > llvm-dev at lists.llvm.org > http://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/20161012/d80bfd1c/attachment.html>
Hal Finkel via llvm-dev
2016-Oct-12 23:09 UTC
[llvm-dev] [RFC] Increase minimum supported GCC version for building LLVM to 4.8
This makes sense to me. Especially since, in practice, we've already done it ;) -Hal ----- Original Message -----> From: "Reid Kleckner via llvm-dev" <llvm-dev at lists.llvm.org> > To: "Teresa Johnson" <tejohnson at google.com> > Cc: "llvm-dev" <llvm-dev at lists.llvm.org> > Sent: Wednesday, October 12, 2016 6:05:39 PM > Subject: Re: [llvm-dev] [RFC] Increase minimum supported GCC version > for building LLVM to 4.8> +1. I've been bitten by the 4.7 STL's lack of std::map::emplace a few > times, so I support this.> On Wed, Oct 12, 2016 at 3:51 PM, Teresa Johnson via llvm-dev < > llvm-dev at lists.llvm.org > wrote:> > According to the documentation at > > http://llvm.org/docs/GettingStarted.html#software , 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. >> > This is split off of the thread started here: > > > http://lists.llvm.org/pipermail/llvm-dev/2016-October/105742.html > > > 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. >> > 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: > > > http://lists.llvm.org/pipermail/llvm-dev/2016-October/105825.html >> > Renato also suggests bumping the minimum to 4.8, as that is the > > oldest shipped version in most stable Linux distributions: > > > http://lists.llvm.org/pipermail/llvm-dev/2016-October/105826.html >> > 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. >> > Thoughts? >> > Thanks, > > > Teresa >> > -- >> > Teresa Johnson | Software Engineer | tejohnson at google.com | > > 408-460-2413 > > > _______________________________________________ > > > LLVM Developers mailing list > > > llvm-dev at lists.llvm.org > > > http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev >> _______________________________________________ > LLVM Developers mailing list > llvm-dev at lists.llvm.org > http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev-- Hal Finkel Lead, Compiler Technology and Programming Languages Leadership Computing Facility Argonne National Laboratory -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20161012/80206d5a/attachment.html>
Krzysztof Parzyszek via llvm-dev
2016-Oct-12 23:11 UTC
[llvm-dev] [RFC] Increase minimum supported GCC version for building LLVM to 4.8
On 10/12/2016 6:05 PM, Reid Kleckner via llvm-dev wrote:> +1. I've been bitten by the 4.7 STL's lack of std::map::emplace a few > times, so I support this.Same here. I still remember the disappointment about the emplace. +1 -Krzysztof
Joerg Sonnenberger via llvm-dev
2016-Oct-12 23:28 UTC
[llvm-dev] [RFC] Increase minimum supported GCC version for building LLVM to 4.8
On Wed, Oct 12, 2016 at 03:51:07PM -0700, Teresa Johnson via llvm-dev wrote:> According to the documentation at > http://llvm.org/docs/GettingStarted.html#software, 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.Fine with me. Joerg
Pete Cooper via llvm-dev
2016-Oct-12 23:59 UTC
[llvm-dev] [RFC] Increase minimum supported GCC version for building LLVM to 4.8
+1 from me. But which version of 4.8.x? 4.8.0 was released in March 2013 while 4.8.5 is June 2015 (see https://gcc.gnu.org/releases.html <https://gcc.gnu.org/releases.html>) Thats an awfully long time between those dates, so i can’t imagine everyone being on 4.8.5, but shouldn’t we aim for the highest possible one if we’re bumping versions anyway? Looking at Ubuntu 14.04 LTS (http://packages.ubuntu.com/search?keywords=gcc-4.8 <http://packages.ubuntu.com/search?keywords=gcc-4.8>), appears that 4.8.4 is available for many platforms, so if possible that might be a good version to do. Cheers, Pete> On Oct 12, 2016, at 4:28 PM, Joerg Sonnenberger via llvm-dev <llvm-dev at lists.llvm.org> wrote: > > On Wed, Oct 12, 2016 at 03:51:07PM -0700, Teresa Johnson via llvm-dev wrote: >> According to the documentation at >> http://llvm.org/docs/GettingStarted.html#software, 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. > > Fine with me. > > Joerg > _______________________________________________ > LLVM Developers mailing list > llvm-dev at lists.llvm.org > http://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/20161012/3a209e27/attachment.html>
Justin Bogner via llvm-dev
2016-Oct-13 04:14 UTC
[llvm-dev] [RFC] Increase minimum supported GCC version for building LLVM to 4.8
Teresa Johnson via llvm-dev <llvm-dev at lists.llvm.org> writes:> According to the documentation at > http://llvm.org/docs/GettingStarted.html#software, 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.-1 unless it's particularly hard to fix the incompatibilities that have been introduced or there are strong pain points in supporting 4.7.4. We should only increase the minimum version of our host compilers if we have strong motivation to do so.
Daniel Berlin via llvm-dev
2016-Oct-13 04:42 UTC
[llvm-dev] [RFC] Increase minimum supported GCC version for building LLVM to 4.8
On Wed, Oct 12, 2016 at 9:14 PM, Justin Bogner via llvm-dev < llvm-dev at lists.llvm.org> wrote:> Teresa Johnson via llvm-dev <llvm-dev at lists.llvm.org> writes: > > According to the documentation at > > http://llvm.org/docs/GettingStarted.html#software, 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. > > -1 unless it's particularly hard to fix the incompatibilities that have > been introduced or there are strong pain points in supporting 4.7.4. We > should only increase the minimum version of our host compilers if we > have strong motivation to do so. >We do: Everyone we care about has already done so, including not just all developers, but all users anyone can find. Nobody is testing or ensuring it builds with 4.7, nor is there any compelling reason anyone can give to do so Testing with 4.7 would actually require people go and install non-default compilers for their long term supported distros in the buildbots, etc (that's a pain point right there). Last i looked, 3.9 did not even build with gcc 4.7, and not a single complaint, bug filed, etc. (note: I haven't double checked this, it was definitely true at one point). Even the case where someone noticed that Teresa points out is an odd case, and not a normal usage. I think the above is a pretty strong motivation, even if it's not the typical motivation of "it adds x feature we want". We can certainly offer support for 4.7 if we want to, but if we are offering 4.7 just because 4.8 doesn't have magical new features that we would upgrade to, that seems wrong. We should offer support for 4.7 because someone actually wants it, and we care about that someone. Otherwise, it fails the very trivial test of "who cares if we support 4.7 or not" -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20161012/b47adf05/attachment.html>
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