GCC version for RTEMS 6?

[Chris Johns]

On 28/4/2022 6:04 pm, Sebastian Huber wrote:
> On 28.04.22 09:52, Chris Johns wrote:
>> On 27/4/2022 4:57 pm, Sebastian Huber wrote:
>>> Hello,
>>>
>>> we have to select a GCC version for the RTEMS 6 release. Currently, GCC 10 is
>>> used, however, with the release of GCC 10.4 this year it will reach its end of
>>> life. Other options are GCC 11 and 12. GCC 12 will be released in the next
>>> weeks. It has some nice features:
>>>
>>> * Initialization of stack variables:
>>>
>>> https://gcc.gnu.org/onlinedocs/gcc/Optimize-Options.html#index-ftrivial-auto-var-init
>>>
>>>
>>>
>>> * Improved static analysis with -fanalyzer
>>>
>>> * Improved gcov support, with the ability to back port changes from GCC 13:
>>>
>>> https://gcc.gnu.org/pipermail/gcc-patches/2022-April/593536.html
>>>
>>> * Upstream maintenance for the next three years
>>>
>>> The draw back is that it is brand new.
>>>
>> What about rtems 6 shipping with 10 and then we move to 12 and test and if it
>> looks good we release 7?
>>
>> The rational is my testing with rtems 6 + gcc 10 is good so we have a stable
>> base to move from. Without this step we have no means for users to move back if
>> there are issues.
> 
> More releases means more maintenance overhead. Since GCC 12 is under active
> upstream maintenance, compiler issues can be fixed by the GCC maintainers in
> contrast to GCC 10.

Yes it does mean that could happen but it also means 6 and 7 are closer in terms
of rtems.git etc so back ports here are simpler. Plus if rtems 6 is not working
and 7 is the user can just move forward to 7.

I suppose there is no prefect solution and we do not have a crystal ball so we
will have to decide and hope we are OK.

The positive aspect is 6 and 7 will both be waf based and that helps deployment
solutions user have, eg EPICS.

Chris