Re: [PATCH 1/4] selftests: lib: allow to override CC in the top-level Makefile

[Daniel DÃaz]

Hello!

On Wed, 16 Jan 2019 at 15:56, shuah <shuah@xxxxxxxxxx> wrote:
>
> On 1/16/19 10:43 AM, Daniel DÃaz wrote:
> > From: Fathi Boudra <fathi.boudra@xxxxxxxxxx>
> >
> > Relax CC assignment to allow to override CC in the top-level Makefile.
> >
> > Signed-off-by: Denys Dmytriyenko <denys@xxxxxx>
> > ---
> >   tools/testing/selftests/lib.mk | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/tools/testing/selftests/lib.mk b/tools/testing/selftests/lib.mk
> > index 8b0f16409ed7..0f9c47eaaa6f 100644
> > --- a/tools/testing/selftests/lib.mk
> > +++ b/tools/testing/selftests/lib.mk
> > @@ -1,6 +1,6 @@
> >   # This mimics the top-level Makefile. We do it explicitly here so that this
> >   # Makefile can operate with or without the kbuild infrastructure.
> > -CC := $(CROSS_COMPILE)gcc
> > +CC ?= $(CROSS_COMPILE)gcc
> >
> >   ifeq (0,$(MAKELEVEL))
> >   OUTPUT := $(shell pwd)
> >
>
> What problem does this fix?

Sometimes "$(CROSS_COMPILE)gcc" is not enough: For instance, we need
to pass --sysroot to CC:
  CC="aarch64-linaro-linux-gcc
--sysroot=/oe/build/tmp-lkft-glibc/work/hikey-linaro-linux/kselftests-mainline/4.19-r0/recipe-sysroot"

Greetings!

Daniel DÃaz
daniel.diaz@xxxxxxxxxx