[U-Boot] [PATCH v3] config.mk: fix -fstack-usage support test

[Masahiro Yamada]

Hello Albert


> Much better than the previous one (with a nitpick: superfluous "s" in
> "This commits")... But now we lack the rationale part, which was
> dropped rather than moved after the '---' line. 

I will add the rationale part in v4 along with s/commits/commit/.
Thanks.


> Regarding the patch itself, why a shell script rather than a variant
> of cc-option?

We cannot simply test -fstack-option support by $(call cc-option,...)

This was mentioned in version 1 discussion,
(I should have written this below the '---')

> So, I looked into it more closely and
> I found gcc can compile the input file /dev/null successfully
> even if -fstack-usage is not supported.
> 
> 
>     $ bfin-uclinux-gcc -fstack-usage -S -xc /dev/null 
>     $ echo $?
>     0
>     $ bfin-uclinux-gcc -Werror -fstack-usage -S -xc /dev/null 
>     $ echo $?
>     0


I chose a shell script because I wanted to keep Makefile cleaner
and this is the way Linux Kernel often uses.

Please refer to
 - scripts/gcc-goto.sh
 - scripts/gcc-version.sh
etc. of Linux Kernel.


Best Regards
Masahiro Yamada