Re: sparc: clang: error: unknown argument: '-mno-fpu'

From: Nick Desaulniers
Date: Fri Mar 19 2021 - 14:10:03 EST


On Fri, Mar 19, 2021 at 4:56 AM Arnd Bergmann <arnd@xxxxxxxx> wrote:
>
> On Fri, Mar 19, 2021 at 12:38 PM John Paul Adrian Glaubitz
> <glaubitz@xxxxxxxxxxxxxxxxxxx> wrote:
> > On 3/19/21 12:31 PM, Arnd Bergmann wrote:
> > > On Fri, Mar 19, 2021 at 8:36 AM Naresh Kamboju
> > > <naresh.kamboju@xxxxxxxxxx> wrote:
> > >>
> > >> Linux mainline master build breaks for sparc defconfig.
> > >> There are multiple errors / warnings with clang-12 and clang-11 and 10.
> > >> - sparc (defconfig) with clang-12, clang-11 and clang-10
> > >> - sparc (tinyconfig) with clang-12, clang-11 and clang-10
> > >> - sparc (allnoconfig) with clang-12, clang-11 and clang-10
> > >>
> > >> make --silent --keep-going --jobs=8
> > >> O=/home/tuxbuild/.cache/tuxmake/builds/1/tmp ARCH=sparc
> > >> CROSS_COMPILE=sparc64-linux-gnu- 'HOSTCC=sccache clang' 'CC=sccache
> > >> clang'
> > >
> > > I don't think anyone has successfully built a sparc kernel with clang,
> > > and I don't
> > > think it's worth trying either, given how little upstream work the
> > > sparc port sees overall.
> >
> > We'll get there. There are some other SPARC-related clang bugs that need
> > to be squashed first. We have made quite some improvements and it's actually
> > maintained by the community. Of course, we don't have a commercial backer
> > but that shouldn't be necessary for open source to work.
>
> I meant there is no point for Naresh to do it as part of his build
> testing with tuxmake.
> If someone else gets it working, they can tell Naresh to try again, but until
> then, I'd limit clang regression testing to x86, arm, powerpc, s390, mips, riscv
> and arc.

We definitely cannot yet build arc.
$ cmake ... -DLLVM_EXPERIMENTAL_TARGETS_TO_BUILD="ARC"
$ ARCH=arc CROSS_COMPILE=arc-linux-gnu- make LLVM=1 -j72 defconfig vmlinux
...
clang-13: error: unknown argument: '-mmedium-calls'
clang-13: error: unknown argument: '-fsection-anchors'
clang-13: error: unknown argument: '-mlock'
clang-13: error: unknown argument: '-mswape'
clang-13: error: unknown argument: '-mno-sdata'
clang-13: error: unknown argument: '-fcall-used-gp'


--
Thanks,
~Nick Desaulniers