Re: [gentoo-dev] [PATCH v2] kernel-2.eclass: Respect portage CC & AR variables

[James Beddek]

On Friday, 17 December 2021 8:29:18 AM NZDT Adrian Ratiu wrote:
> Hi Andrew,
>
> On Thu, 16 Dec 2021, Andrew Savchenko <bircoph@g.o> wrote:
> > On Thu, 16 Dec 2021 03:32:10 +0300 Andrew Savchenko wrote:
> >> On Wed, 15 Dec 2021 16:58:26 +0200 Adrian Ratiu wrote:
> >> > Starting with kernel>=v5.7 the build system can override the
> >> > tools vars by setting LLVM=1 [1], but older kernels still use
> >> > the default GNU tools, so to be able to use a full LLVM/Clang
> >> > build, CC should be set together with AR to the portage set
> >> > values.   Doing this avoids situations like building the
> >> > kernel with clang (using the set HOSTCC) but using gcc/gnu-ar
> >> > for headers.   [1] a0d1c951ef08 kbuild: support LLVM=1 to
> >> > switch the default tools to Clang/LLVM  Co-authored-by: Manoj
> >> > Gupta <manojgupta@××××××××.org> Signed-off-by: Adrian Ratiu
> >> > <adrian.ratiu@×××××××××.com> ---
> >> >
> >> >  eclass/kernel-2.eclass | 2 +- 1 file changed, 1
> >> >  insertion(+), 1 deletion(-)
> >> >  diff --git a/eclass/kernel-2.eclass b/eclass/kernel-2.eclass
> >> >
> >> > index adc1425bc2e..caeec86ff59 100644 ---
> >> > a/eclass/kernel-2.eclass +++ b/eclass/kernel-2.eclass @@
> >> > -692,7 +692,7 @@ env_setup_xmakeopts() {
> >> >
> >> >  	elif type -p ${CHOST}-ar >/dev/null; then
> >> >
> >> >  xmakeopts="${xmakeopts} CROSS_COMPILE=${CHOST}-" fi
> >> >
> >> > -	xmakeopts="${xmakeopts} HOSTCC=$(tc-getBUILD_CC)" +
> >> > xmakeopts="${xmakeopts} HOSTCC=$(tc-getBUILD_CC)
> >> > CC=$(tc-getCC) AR=$(tc-getAR)"
> >>
> >>  OBJDUMP should be exported as well (e.g. used by
> >>
> >> scripts/Makefile.build)
> >
> > And LD as well.
>
> Thank you very much for the suggestions!
>
> I only set CC and AR because there were the two which failed in my
> testing, but yes, it is a good idea to be prudent and set them all
> if nobody is oopposed to it.
>

I assume by set them all you're referring to what the kernel makefile uses? I 
think CC, LD, AR, NM, OBJCOPY, OBJDUMP, READELF, and STRIP is the exhaustive 
list for the kernel. (would match the new clang profile feature too)

Thanks

> I will leave this patch on the ML a bit in case there is more
> feedback (it is also EoY season so people might be busy), then I
> will send a v3 with the new variables included.
>
> Thanks again,
> Adrian
>
> >> >  	export xmakeopts
> >> >
> >> >  }
> >>
> >> Best regards,
> >> Andrew Savchenko
> >
> > Best regards,
> > Andrew Savchenko