On 6/3/24 10:09 AM, John Hubbard wrote:
On 6/3/24 8:32 AM, Mark Brown wrote:
On Fri, May 31, 2024 at 11:37:50AM -0700, John Hubbard wrote:
The kselftests may be built in a couple different ways:
make LLVM=1
make CC=clang
In order to handle both cases, set LLVM=1 if CC=clang. That way,the rest
of lib.mk, and any Makefiles that include lib.mk, can base decisions
solely on whether or not LLVM is set.
ICBW but I believe there are still some architectures with clang but not
lld support where there's a use case for using CC=clang.
I'm inclined to wait for those to make themselves known... :)
...but thinking about this some more, maybe this patch is actually
a Bad Idea. Because it is encouraging weirdness and divergence from
how kbuild does it. And kbuild is very clear [1]:
Building with LLVM
Invoke make via:
make LLVM=1
to compile for the host target. For cross compiling:
make LLVM=1 ARCH=arm64
The LLVM= argument
LLVM has substitutes for GNU binutils utilities. They can be enabled individually. The full list of supported make variables:
make CC=clang LD=ld.lld AR=llvm-ar NM=llvm-nm STRIP=llvm-strip \
OBJCOPY=llvm-objcopy OBJDUMP=llvm-objdump READELF=llvm-readelf \
HOSTCC=clang HOSTCXX=clang++ HOSTAR=llvm-ar HOSTLD=ld.lld
LLVM=1 expands to the above.
[1] https://docs.kernel.org/kbuild/llvm.html
thanks,
--
John Hubbard
NVIDIA
