Re: [powerpc:next-test 54/220] arch/powerpc/kernel/vdso32/vgettimeofday.c:13:5: warning: no previous prototype for function '__c_kernel_clock_gettime64'

On Mon, Dec 7, 2020 at 4:23 AM Michael Ellerman [off-list ref] wrote:

So is clang defining __powerpc64__ even for 32-bit code?

And the answer appears to be yes:

  $ clang --version
  Ubuntu clang version 11.0.0-2
  Target: powerpc64le-unknown-linux-gnu

  $ clang -m32 -dM -E - < /dev/null | grep powerpc
  #define __powerpc64__ 1
  #define __powerpc__ 1

Compare to gcc:

  $ gcc --version
  gcc (Ubuntu 10.2.0-13ubuntu1) 10.2.0

  $ gcc -m32 -dM -E - < /dev/null | grep powerpc
  #define __powerpc__ 1
  #define powerpc 1
  #define __powerpc 1


Which is fairly problematic, because we use the presence/absence of
__powerpc64__ to determine if we're building 64-bit/32-bit code in
several places.

Not sure what the best approach for fixing that is.

Thanks for the triage; we should fix our preprocessor:
https://bugs.llvm.org/show_bug.cgi?id=48427
-- 
Thanks,
~Nick Desaulniers