[libcamera-devel] [PATCH 2/4] meson: enable no-psabi for gcc 9+

[Tomi Valkeinen]

On 09/10/2020 04:37, Laurent Pinchart wrote:

>> I don't think I get this whole thing =). But I'm fine with increasing
>> the version check to < 10, as I'm currently using gcc 9. I'll probably
>> switch my buildroot to gcc 10 at some point in the near future, and
>> then I can send a new patch.
> 
> The idea is that I'd like to keep an eye on ABI breakages introduced by
> gcc, in a "just for my information" fashion for the moment. I don't know
> at this point how such breakages would even be handled (if at all).
> 
> "Just for my information" is probably not a good enough excuse to annoy
> everybody with warnings when using new compiler versions though. I'd
> thus agree to drop the version check. I wonder how the gcc developers
> had envisioned this being used though, if there's a warning (which is
> actually not even a warning, but a note), I imagine it was put there
> with a target audience in mind. Or maybe this is just a mess and nobody
> should really pay attention :-)

Ok. Yes, I don't get this either. What would make sense is, e.g. "-Wno-psabi=1,4", which would
disable warnings for ABI breakages #1 and #4, but allow all the other warnings.

What I did in kms++ was just:

if (cpp.get_id() == 'gcc' and
    host_machine.cpu_family() == 'arm' and
    cpp.has_argument('-Wno-psabi'))

    cpp_arguments += [
        '-Wno-psabi',
    ]
endif

It's silly to always disable the warning, but I haven't found much info about it while googling, so
currently I'm guessing it's the "this is just a mess" case.

 Tomi