Re: [PATCH] ARM: mtd-xip: work around clang/llvm bug

From: Arnd Bergmann
Date: Tue Jul 09 2019 - 14:41:12 EST


On Tue, Jul 9, 2019 at 8:08 PM 'Nick Desaulniers' via Clang Built
Linux <clang-built-linux@xxxxxxxxxxxxxxxx> wrote:
> On Tue, Jul 9, 2019 at 1:41 AM Linus Walleij <linus.walleij@xxxxxxxxxx> wrote:
>
> > I guess this brings up the old question whether the compiler should
> > be worked around or just considered immature, but as it happens this
>
> Definitely a balancing act; we prioritize work based on what's
> feasible to work around vs must be implemented. A lot of my time is
> going into validation of asm goto right now, but others are ramping up
> on the integrated assembler (clang itself can be invoked as a
> substitute for GNU AS; but there's not enough support to do `make
> AS=clang` for the kernel just yet).

Note that this bug is the same with both gas and AS=clang, which also
indicates that clang implemented the undocumented .rep directive
for compatibility.

Overall I think we are at the point where building the kernel with clang-8
is mature enough that we should work around bugs like this where it is
easy enough rather than waiting for clang-9.

Arnd