How will user's compile with Makefiles? Was: Re: large bss size for sample applications

[Pavel Pisa]

Hello Chris,

On Friday 02 of October 2015 11:25:23 Chris Johns wrote:
> I am not really following this. To use 'rtems-config' in GNU make all
> you need to do is something like (this is made up by me):
>
>  CC=$(shell rtems-config cc)
>  LD=$(shell rtems-config ld)
>  CFLAGS=$(shell rtems-config cflags)
>  LDFLAGS=$(shell rtems-config ldflags)
>
> This could be in a template in a git repo on rtems.org or a wiki page.
> What ever works. Pavel has raised possible performance issues and we
> need to consider this when the time comes. In my example this is just a
> few shell forks which is fast.

Yes that is generally OK. You are right that overhead is small
and we use same setup with pkgconfig in some cases already.
If caching is required then it is probably better
on application side then on infrastructural.

But rtems-config tool makes me a little nervous. If it is part
of RTEMS BSP install directory then it is in a perfect match with
RTEMS sources version used to build BSP. If it is installed
to /opt/rtems4.xx (given version install prefix) then it can be
problem if there are more BSPs build at different time and you do not use
different prefix for each. If rtems-config is global then you have
to maintain solution to be compatible with all RTEMS builds and versions
in future. So from my side, I would prefer mostly stable file location
and format as the values source than the tool.

But both would work and if the tool has pkgconfig compatible syntax
then it would have some advances. Or even "database" format can be
directly compatible with pkgconfig even that it is not my
preferred format.

Important form me is if solution is checked/discussed enough
to catch possible problems which would be hard to correct
in future.

Best wishes,

              Pavel