Re: [boost] Let's discuss dropping support for msvc <= 9.0 (2008), gcc < 4.6, clang < 3.4

Subject: Re: [boost] Let's discuss dropping support for msvc <= 9.0 (2008), gcc < 4.6, clang < 3.4
From: jrmarsha (jrmarsha_at_[hidden])
Date: 2018-12-12 16:55:53

Wouldn't dropping gcc 4.6 drop support for RHEL 7.x?  That might cause 
some off-the-wall problems for some users.  Can anyone speak to this 
with any more knowledge?

On 12/12/18 9:53 AM, James E. King III via Boost wrote:
> During the Boost 1.69.0 release there was a regression on Visual Studio
> 2005 (msvc-8.0).  Microsoft ended support for msvc-8.0 on December 4,
> 2016.  I was going to argue we let it happen, but it wasn't the right time
> to discuss that sort of change.
>
> Boost has a very large compatibility matrix which increases the effort
> required, and sometimes limits solutions development, to get out a quality
> release.  The boost project as a whole agreed in summer 2018 that if
> repository maintainers wanted to drop C++03 support per repository to make
> substantial improvements or simplifications, or to ease maintenance then
> they are able to do so.  *Folks who need support for older language levels
> and older compilers can always download an older version of Boost.*
>
> The compilers I mentioned in the subject have trouble with C++11 and are no
> longer maintained.
>
> msvc-8.0 (Visual Studio 2005) ended support Dec 10 2016
> msvc-9.0 (Visual Studio 2018) ended support April 10 2018
> The last release of gcc 4.6 was April 12, 2013
> The last release of gcc 4.5 was July 02, 2012
> The last release of gcc 4.4 was March 13, 2012
> The compilers by default in Ubuntu Trusty 14.04.5 LTS, supported through
> April 2019, is gcc-4.8, currently at gcc-4.8.2, and clang 3.4 (however
> clang-3.8 is available).
>
> My argument is that this is a huge project, and maintaining backwards
> compatibility is not always efficiently possible.  We spend build matrix
> resources testing and analyzing those tests.  We find and develop fixes and
> workarounds.  In some cases we hobble potential solutions to cater to
> decade-old compilers.
>
> Given the summer 2018 discussions about language level, and the aging
> vendor support matrix, I'd like us to consider dropping support for msvc <=
> 9.0 (2008), gcc < 4.6, clang < 3.4.  What does this mean exactly?
>
> 1. We no longer test these compilers in the post-commit build matrix.
> 2. We no longer test these compilers in continuous integration.
> 3. We no longer develop fixes for issues that affect these compilers.
> 4. We are allowed, over time, to remove workarounds for these compilers.
> 5. We no longer block releases due to incompatibility with these compilers.
> 6. We remove these compilers from the documented environments in the
> release notes.
> 7. We direct anyone looking for support of these compilers to download a
> previous release of Boost that given them that support.
> 8. We do not update older Boost releases to fix issues with older compiler
> support.
>
> What would we remove from the release notes as a result?
>
> primary:
>    linux:
>      clang:
>        c++03: 3.0
>        c++0x: 3.0
>        c++11: 3.0, 3.1, 3.2, 3.3
>      gcc:
>        c++03: 4.4.7, 4.5.3
>        c++0x: 4.4.7
>    windows:
>      gcc:
>        c++03: 3.4.5, 4.1.2, 4.2.4, 4.3.3, 4.4.0, 4.5.4
>      msvc:
>        - msvc-7.0 (Visual C++ 7.1)
>        - msvc-8.0 (Visual Studio 2005)
>        - msvc-9.0 (Visual Studio 2008)
> additional:
>    linux:
>      clang:
>        c++03: 3.0, 3.8.1, 3.9.1, 4.0.1
>        c++0x: 3.0
>        c++11: 3.0, 3.1, 3.2, 3.3
>      gcc:
>        c++03: 4.4.7, 4.5.3
>        c++0x: 4.4.7
>    windows:
>      gcc:
>        c++03: 3.4.5, 4.1.2, 4.2.4, 4.3.3, 4.4.0, 4.5.4
>      msvc:
>        - msvc-7.0 (Visual C++ 7.1)
>        - msvc-8.0 (Visual Studio 2005)
>        - msvc-9.0 (Visual Studio 2008)
>
> The release notes section on compiler compatibility should probably be
> updated to match the current state of the post-commit matrix and duplicates
> in the "additional" section that are present in the "primary" section
> should be removed, or simply merge them.  Why do we have a distinction here?
>
> Thanks for your consideration,
>
> Jim
>
> _______________________________________________
> Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost