Thanks Jim. I’ve merged the PR to enable this change.
> On Jan 5, 2018, at 2:38 PM, Jim Ingham <jing...@apple.com> wrote: > > I have no formal objections to switching lldb to C++14. I haven't been > following what is in C++14, but presumably it's purely additive? If so then > except for bugs this should be a no-op. > > My only reservation is it seems a little odd to adopt a "use C++14" policy > for Swift lldb and not for llvm.org lldb. Is clang going to move to C++14 > some time soon? I don't remember seeing anything about this on the lldb dev > lists. If we're going to build GitHub lldb this way it would be worth > raising the suggestion on the lldb-dev as well. > > And of course, all this is dependent on lldb actually building and passing > the testsuite built with C++14. Has somebody tried that? > > Jim > > > >> On Jan 3, 2018, at 8:46 PM, Ted Kremenek via swift-lldb-dev >> <swift-lldb-...@swift.org> wrote: >> >> I’m pinging some folks, but not everybody is back yet. I hope to resolve >> this ASAP. >> >> On Jan 2, 2018, at 11:33 AM, Saleem Abdulrasool <compn...@compnerd.org> >> wrote: >> >>> On Wed, Dec 20, 2017 at 4:26 PM, Ted Kremenek <kreme...@apple.com> wrote: >>> >>> On Dec 19, 2017, 8:33 PM -0800, Ted Kremenek via swift-dev >>> <swift-dev@swift.org>, wrote: >>>> >>>> >>>> On Dec 19, 2017, at 5:08 PM, Saleem Abdulrasool <compn...@compnerd.org> >>>> wrote: >>>> >>>>> >>>>> >>>>>> On Dec 19, 2017, at 3:59 PM, Ted Kremenek <kreme...@apple.com> wrote: >>>>>> >>>>>> >>>>>> >>>>>>> On Dec 19, 2017, at 2:31 PM, Daniel Dunbar <daniel_dun...@apple.com> >>>>>>> wrote: >>>>>>> >>>>>>> >>>>>>> >>>>>>>> On Dec 19, 2017, at 2:27 PM, Ted Kremenek <kreme...@apple.com> wrote: >>>>>>>> >>>>>>>> Fair enough. >>>>>>>> >>>>>>>> We care about swiftc and llbuild building a variety of platforms today >>>>>>>> — FreeBSD, Rasberry Pi, etc. My impression is that C++14 is generally >>>>>>>> supported by both (a) the mininum versions of the distributions we >>>>>>>> support today and (b) the current versions of the platforms we’d like >>>>>>>> to expand Swift to in the future. Does that sound right? I suspect >>>>>>>> you went through the same kind of reasoning with llbuild. >>>>>>> >>>>>>> It sounds reasonable, but to be honest I never did an audit of what >>>>>>> platforms supported C++14. >>>>>> >>>>>> Interesting. Was that not a concern when that choice was made for >>>>>> llbuild, or was the context different? >>>>>> >>>>>>> >>>>>>> I do think that we could always use the Clang++ we build as part of >>>>>>> Swift to build Swift itself. By that logic, it seems reasonable to >>>>>>> expect we could always have C++14 support, although it does mean that >>>>>>> porters would need modern Clang to support their platform. However, >>>>>>> that is likely largely a prerequisite for Swift to work as well. >>>>>> >>>>>> That’s a significant change to make just to get C++14 support >>>>>> guaranteed, and (I believe) would have a non-trivial impact on those >>>>>> using development environments that expect to use the Clang bundled with >>>>>> them to build projects. >>>>> >>>>> Agreed. However, the current supported platforms already support this >>>>> minimum. I think that future platforms will need to provide that >>>>> anyways. If the system doesn’t have a modern toolchain available, I >>>>> suspect that it already would not have C++11 available either. In such a >>>>> scenario, they need to provide a newer toolchain, and so the difference >>>>> there is minimal as we already require C++11. >>>> >>>> OK, I’m convinced. >>>> >>>> I want to hold off for a tiny bit just to see if anyone else has any >>>> commentary on this thread before we make a change. >>> >>> We’d also need to make this change on the LLDB side, and I realize now that >>> a few people I’d like to weigh in are on vacation until the holidays. How >>> about we pick this up immediately in the new year once it’s clear everyone >>> that should weigh in has had a chance to do so. >>> >>> Just a post-holiday bump to bring this back up :-). I'd like to get this >>> merged so that the other Windows stuff is unblocked. >>> >>>> >>>> >>>>> >>>>>>> >>>>>>> - Daniel >>>>>>> >>>>>>>> >>>>>>>> On Dec 19, 2017, 2:23 PM -0800, Daniel Dunbar >>>>>>>> <daniel_dun...@apple.com>, wrote: >>>>>>>>> It wasn’t changed, it has *always* been C++14 since the day we open >>>>>>>>> sourced it. I only investigated the platforms we officially support >>>>>>>>> (Ubuntu 14.04/15.10 at the time, and macOS 10.10+ IIRC). >>>>>>>>> >>>>>>>>> - Daniel >>>>>>>>> >>>>>>>>>> On Dec 19, 2017, at 2:21 PM, Ted Kremenek <kreme...@apple.com> wrote: >>>>>>>>>> >>>>>>>>>> Daniel, >>>>>>>>>> >>>>>>>>>> When you changed llbuild to require C++14, what platforms did you >>>>>>>>>> take into account with that change? If you have already done the >>>>>>>>>> assessment here it could speed a resolution of a decision. >>>>>>>>>> >>>>>>>>>> Thanks, >>>>>>>>>> Ted >>>>>>>>>> >>>>>>>>>>> On Dec 13, 2017, at 3:19 PM, Daniel Dunbar via swift-lldb-dev >>>>>>>>>>> <swift-lldb-...@swift.org> wrote: >>>>>>>>>>> >>>>>>>>>>> FWIW, llbuild requires C++14. >>>>>>>>>>> >>>>>>>>>>> We have to do some minor shenanigans to workaround bugs in >>>>>>>>>>> libstdc++ on 14.04, and our use is probably minimal, but just >>>>>>>>>>> throwing that out there. >>>>>>>>>>> >>>>>>>>>>> - Daniel >>>>>>>>>>> >>>>>>>>>>>> On Dec 13, 2017, at 1:45 PM, Jordan Rose via swift-lldb-dev >>>>>>>>>>>> <swift-lldb-...@swift.org> wrote: >>>>>>>>>>>> >>>>>>>>>>>> No one else has commented on this yet today, so I'll put in that I >>>>>>>>>>>> don't have any objections to this and don't foresee any major >>>>>>>>>>>> problems. The one place where we'd need to be careful is with >>>>>>>>>>>> LLDB, which imports Swift headers; if Swift is going to move to >>>>>>>>>>>> C++14, then Swift-LLDB probably has to as well. LLDB folks, what >>>>>>>>>>>> do you think? >>>>>>>>>>>> >>>>>>>>>>>> The other thing to check is if our minimum Clang or libstdc++ >>>>>>>>>>>> requirements on Linux didn't support C++14. It looks like our >>>>>>>>>>>> README is vague on that, but LLDB already suggests a minimum >>>>>>>>>>>> requirement of Clang 3.5, which is new enough. I suspect we're >>>>>>>>>>>> okay here. >>>>>>>>>>>> >>>>>>>>>>>> Jordan >>>>>>>>>>>> >>>>>>>>>>>> >>>>>>>>>>>>> On Dec 13, 2017, at 10:36, Saleem Abdulrasool via swift-dev >>>>>>>>>>>>> <swift-dev@swift.org> wrote: >>>>>>>>>>>>> >>>>>>>>>>>>> Hi, >>>>>>>>>>>>> >>>>>>>>>>>>> The newer Windows SDK requires the use of C++14 (the SDK headers >>>>>>>>>>>>> use `auto` return types without trailing type information). Joe >>>>>>>>>>>>> mentioned that there was some interest in switching the rest of >>>>>>>>>>>>> swift to C++14 as well. I figured that I would just start a >>>>>>>>>>>>> thread here to determine if this is okay to do globally rather >>>>>>>>>>>>> than just specifically for the Windows builds to ensure that we >>>>>>>>>>>>> can build the Windows components. >>>>>>>>>>>>> >>>>>>>>>>>>> Thanks. >>>>>>>>>>>>> >>>>>>>>>>>>> -- >>>>>>>>>>>>> Saleem Abdulrasool >>>>>>>>>>>>> compnerd (at) compnerd (dot) org >>>>>>>>>>>>> _______________________________________________ >>>>>>>>>>>>> swift-dev mailing list >>>>>>>>>>>>> swift-dev@swift.org >>>>>>>>>>>>> https://lists.swift.org/mailman/listinfo/swift-dev >>>>>>>>>>>> >>>>>>>>>>>> _______________________________________________ >>>>>>>>>>>> swift-lldb-dev mailing list >>>>>>>>>>>> swift-lldb-...@swift.org >>>>>>>>>>>> https://lists.swift.org/mailman/listinfo/swift-lldb-dev >>>>>>>>>>> >>>>>>>>>>> _______________________________________________ >>>>>>>>>>> swift-lldb-dev mailing list >>>>>>>>>>> swift-lldb-...@swift.org >>>>>>>>>>> https://lists.swift.org/mailman/listinfo/swift-lldb-dev >>>>> >>>> _______________________________________________ >>>> swift-dev mailing list >>>> swift-dev@swift.org >>>> https://lists.swift.org/mailman/listinfo/swift-dev >>> >>> >>> >>> -- >>> Saleem Abdulrasool >>> compnerd (at) compnerd (dot) org >> _______________________________________________ >> swift-lldb-dev mailing list >> swift-lldb-...@swift.org >> https://lists.swift.org/mailman/listinfo/swift-lldb-dev > _______________________________________________ swift-dev mailing list swift-dev@swift.org https://lists.swift.org/mailman/listinfo/swift-dev
