[Buildroot] [PATCH v2 next 1/7] toolchain: add common binutils version hidden config options

[Thomas Petazzoni <thomas.petazzoni@free-electrons.com>]

Hello,

On Tue, 31 May 2016 12:11:12 +0100, Vicente Olivert Riera wrote:
> This commit adds a number of hidden Config.in options, that will be used
> to handle dependencies on the binutils version. We mimic the model that
> was used for the kernel headers dependency mechanism.
> 
> These hidden options will be selected by the internal and external
> toolchain backend logic respectively, in follow-up commits.
> 
> These options will be helpful when we need to make packages depend on
> certain version of binutils. Further patches will do this for gcc and
> valgrind packages.
> 
> Signed-off-by: Vicente Olivert Riera <Vincent.Riera@imgtec.com>
> Reviewed-by: "Yann E. MORIN" <yann.morin.1998@free.fr>

I was about to apply this series, but in fact, I'm going to reject it,
as I believe the annoyance / benefit ratio is not good.

You are introducing those binutils version selectors to solve two
problems:

 * The fact that gcc 4.8 does not work on MIPS with binutils >= 2.25.
   binutils 2.25 is already our default, and as soon as binutils 2.27
   is released, 2.26 will be the default, and 2.24 will be removed,
   leaving in fact no way to select gcc 4.8 on MIPS.

   So I would prefer that we simply disallow gcc 4.8 on MIPS completely.

 * The fact that Valgrind doesn't work on MIPS soft-float with binutils
   >= 2.25. Same comment here: just disable Valgrind on MIPS soft-float
   and that's it.

Normally, the version option are used to indicate that something
*works* only after a certain version (like kernel headers >= 3.10, or
gcc >= 4.9).

But here, you're using the options in the opposite way: to say that
anything after binutils 2.25 (included) is broken. With 2.24 going away
in the near future, I rather prefer the above solutions that to add
those additional binutils version options.

So could you instead submit patches that:

 1/ Disallow gcc 4.8 on MIPS
 2/ Disallow valgrind on MIPS soft-float

Thanks!

Thomas
-- 
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com