[U-Boot] [RFC PATCH] kbuild: use "cc-cross-prefix" to choose CROSS_COMPILE

[Detlev Zundel <dzu@denx.de>]

Hi Masahiro,

> CROSS_COMPILE is generally passed from the command line
> or by the environment variable because cross tools
> vary from user to user.
>
> But, having some choices of often used CROSS_COMPILE
> seems reasonable.
>
> $(call cc-cross-prefix, ...) returns the first prefix
> where a prefix$(CC) is found in PATH.
>
> If your cross tools exist in the argument of
> $(call cc-cross-prefix, ...), you do not have to
> specify it explicitly.
>
> Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>

I have to admit that I don't really like this approach.  On the one hand
it is an heuristic trying to guess the intentions of the user.  This is
nice if it works but can be very surprising when it goes wrong.

But more imprtantly, it will blur the the boundaries of the build
process as we trade the very self contained determinism of "use what
CROSS_COMPILE" says to "use what we may find in the rest of the system".

It would even be possible that a "once working" build process will not
work anymore because the user has installed a new toolchain in the
meantime and then this completely unrelated action has an (unwanted)
impact.

In short, I would rather want to stay with our current (clearly defined)
setup :)

Best wishes
  Detlev

-- 
He who can properly define and divide is to be considered a god.
                                        -- Plato
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