[PATCH 0/2] powerpc: Clang build fixes

[Joel Stanley]

Two fixes to get us closer to building with clang. With a one patch[1]
on top of clang master I can build and boot a powernv kernel:

$ make ARCH=powerpc powernv_defconfig
$ ./scripts/config -e PPC_DISABLE_WERROR -d FTRACE -d BTRFS_FS -d MD_RAID456
$ make CC=/scratch/joel/llvm-build/bin/clang-8 CLANG_TRIPLE=powerpc64le-linux-gnu -j128

$ qemu-system-ppc64 -M powernv -m 3G -nographic -kernel zImage.epapr \
 -L ~/skiboot/ -initrd ~/rootfs.cpio.xz

Linux version 4.19.0-rc3-00003-g728b25f26bce (joel at ozrom3) (clang version 8.0.0 (trunk 341773)) #12 SMP Mon Sep 10 17:32:05 ACST 2018

The DISABLE_WERROR is due to clang's -Wduplicate-decl-specifier. Some
macros we have in arch/powerpc/include/asm/uaccess.h warn on 'const
typeof(var)', where as the GCC version doesn't. Anton did fix this a
while ago, but the fix was 'reverted' to resolve some sparse warnings.
I think we should re-apply Anton's patch[2].

[1] https://reviews.llvm.org/D50965
[2] http://git.kernel.org/torvalds/c/b91c1e3e7a6f22a6b898e345b745b6a43273c973

Joel Stanley (2):
  powerpc/boot: Fix crt0.S syntax for clang
  powerpc/boot: Ensure _zimage_start is a weak symbol

 arch/powerpc/boot/crt0.S | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

-- 
2.17.1