[vlc-devel] [PATCH 2/2] thread: fix compilation with clang 7 or older

[Rémi Denis-Courmont]

Hi,

Well I think all build tools are just as hard to upgrade with the exception of those that get back-ported.

And Clang is in the later category due to LLVM-based reverse dependencies, much easier to update than Meson.

But in any case, what's really hard to update is the runtime. Not any build tool.

Le 25 février 2020 11:33:18 GMT+02:00, Alexandre Janniaux <ajanni at videolabs.io> a écrit :
>Hi,
>
>The main issue with requiring earlier version of Clang is
>that it needs to be shipped in android NDK release too.
>
>Currently it seems to be failing with android NDK 18 (which
>is previous VLC 3 NDK version) but is ok with NDK 21 (which
>is LTS and the current version on VLC 4 and latest VLC 3).
>
>Is it planned to drop support of NDK 18? (or done?).
>
>> Especially not old bugs from a compiler that will be already 3 major
>releases behind by the time VLC 4.0 comes out, while on the other hand
>C++ devs are craving to use C++17 and we require bleeding edge version
>of some other build tools (Meson requirement is so new that you can't
>build contribs on current Ubuntu LTS).
>
>I don't think toolchains and buildsystems are comparable
>with regards to version update. You can be stuck on old
>compilers but still be able to use bleeding edge build
>systems. The case of android is typically one of them.
>
>Regards,
>--
>Alexandre Janniaux
>Videolabs
>
>On Tue, Feb 25, 2020 at 11:06:20AM +0200, Rémi Denis-Courmont wrote:
>> Hi,
>>
>> I don't think it makes sense in general to try to work around
>compiler bugs.
>>
>> Especially not old bugs from a compiler that will be already 3 major
>releases behind by the time VLC 4.0 comes out, while on the other hand
>C++ devs are craving to use C++17 and we require bleeding edge version
>of some other build tools (Meson requirement is so new that you can't
>build contribs on current Ubuntu LTS).
>>
>> Le 25 février 2020 10:24:33 GMT+02:00, Thomas Guillem
><thomas at gllm.fr> a écrit :
>> >
>> >
>> >On Tue, Feb 25, 2020, at 08:34, Rémi Denis-Courmont wrote:
>> >> Hi,
>> >>
>> >> Clang 7 supports what you call C17. It even has a compiler flag
>for
>> >it explicitly. That's all in the LLVM and Clang documentation.
>> >>
>> >> Ergo it works or your compiler is buggy.
>> >
>> >I think that is what ePirat said, clang 7 has the bug.
>> >
>> >Could it be possible to enable this cast on a ifdef clang < 7 ?
>> >
>> >That way, we can easily remove later when we drop clang 7 support.
>> >
>> >>
>> >> Le 25 février 2020 08:36:39 GMT+02:00, Marvin Scholz
>> ><epirat07 at gmail.com> a écrit :
>> >>> On 25 Feb 2020, at 6:56, Rémi Denis-Courmont wrote:
>> >>>
>> >>>> Le maanantaina 24. helmikuuta 2020, 17.45.07 EET Marvin Scholz a
>> >>>> écrit :
>> >>>>> even though it never modifies it.
>> >>>>> Clang versions 7 or older did implement this quite strictly and
>> >>>>> therefore errors when compiling this code:
>> >>>> That's either a bug in that compiler version or possibly a minor
>> >>>> update not
>> >>>> installed, or mistaken compiler flag (in other words, configure
>> >script
>> >>>> bug).
>> >>>> Clang 7 officially supports C17/C18.
>> >>>
>> >>> I tested all major versions before 7 and all are affected.
>> >>> I can’t easily test minor versions between 7 or 8 as they are not
>> >>> available
>> >>> on godbolt. Looking at the git repository though it seems the
>first
>> >>> fixed
>> >>> version was 8.0.0.
>> >>>
>> >>> Not sure what you mean by mistaken compiler flag here?
>> >>>
>> >>> >
>> >>>>  And to call it C17 is a bit of a stretch. It's really just an
>> >>>>  re-edition of
>> >>>>  C11 with editorial corrections gathered. The atomic spelling
>error
>> >was
>> >>>>  already
>> >>>>  found and corrected in 2014.
>> >>>
>> >>> It’s called C17 on open-std.org, thats why I used that here, not
>> >sure
>> >>> what else to
>> >>> call it.
>> >>>
>> >>>>  --
>> >>>>  Реми Дёни-Курмон
>> >>>>  http://www.remlab.net/ vlc-devel mailing list
>> >>>>  To unsubscribe or modify your subscription options:
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>> >>> vlc-devel mailing list
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>> >>
>> >> --
>> >> Envoyé de mon appareil Android avec Courriel K-9 Mail. Veuillez
>> >excuser ma brièveté.
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>> --
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>excuser ma brièveté.
>
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-- 
Envoyé de mon appareil Android avec Courriel K-9 Mail. Veuillez excuser ma brièveté.
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