Re: [PATCH] kbuild: add script check for cross compilation utilities

Masahiro Yamada
2019-05-12T03:05:31Z

On Sat, May 11, 2019 at 11:25 AM Nathan Chancellor
<natechancellor@gmail.com> wrote:
>
> Few comments below but nothing major, this seems to work fine as is.
>
> On Thu, May 09, 2019 at 01:19:21PM -0700, 'Nick Desaulniers' via Clang Built Linux wrote:
> > When cross compiling via setting CROSS_COMPILE, if the prefixed tools
> > are not found, then the host utilities are often instead invoked, and
> > produce often difficult to understand errors. This is most commonly the
> > case for developers new to cross compiling the kernel that have yet to
> > install the proper cross compilation toolchain. Rather than charge
> > headlong into a build that will fail obscurely, check that the tools
> > exist before starting to compile, and fail with a friendly error
> > message.
>
> This part of the commit message makes it sound like this is a generic
> problem when it is actually specific to clang. make will fail on its
> own when building with gcc if CROSS_COMPILE is not properly set (since
> gcc won't be found).
>
> On a side note, seems kind of odd that clang falls back to the host
> tools when a non-host --target argument is used... (how in the world is
> that expected to work?)

I agree.
Failure is much better than falling back to host tools.

--
Best Regards
Masahiro Yamada