On Tue, Oct 13, 2026 at 12:40 PM Mark Brown <[email protected]> wrote:
>
> The kselftest_deps.sh script currently takes a compiler as the first
> argument and uses it to check that libraries needed by the selftests
> are installed. This works well for GCC where a separate binary is
> provided for each target architecture but is less of a good fit for
> LLVM where a single compiler binary can target all of the supported
> architetures. Extend the script to accept "LLVM" as the compiler with
> an additional optional ARCH= argument so that it can be used when
> building with LLVM in a similar fashion to how the actual build works.
>
> The duplication with the main Makefile isn't ideal here.
>
> Signed-off-by: Mark Brown <[email protected]>
> ---
> tools/testing/selftests/kselftest_deps.sh | 83
> +++++++++++++++++++++++++++++--
> 1 file changed, 80 insertions(+), 3 deletions(-)
>
> diff --git a/tools/testing/selftests/kselftest_deps.sh
> b/tools/testing/selftests/kselftest_deps.sh
> index 487e49fdf2a6..70b834361cb7 100755
> --- a/tools/testing/selftests/kselftest_deps.sh
> +++ b/tools/testing/selftests/kselftest_deps.sh
> @@ -10,13 +10,20 @@
> usage()
> {
>
> -echo -e "Usage: $0 -[p] <compiler> [test_name]\n"
> +echo -e "Usage: $0 -[p] <compiler> [ARCH=<arch>] [test_name]\n"
> echo -e "\tkselftest_deps.sh [-p] gcc"
> echo -e "\tkselftest_deps.sh [-p] gcc mm"
> echo -e "\tkselftest_deps.sh [-p] aarch64-linux-gnu-gcc"
> -echo -e "\tkselftest_deps.sh [-p] aarch64-linux-gnu-gcc mm\n"
> +echo -e "\tkselftest_deps.sh [-p] aarch64-linux-gnu-gcc mm"
> +echo -e "\tkselftest_deps.sh [-p] LLVM"
> +echo -e "\tkselftest_deps.sh [-p] LLVM ARCH=arm64 mm\n"
> echo "- Should be run in selftests directory in the kernel repo."
> echo "- Checks if Kselftests can be built/cross-built on a system."
> +echo "- Compiler can be given as LLVM to use clang, as with LLVM=1 in"
> +echo " the kselftest build. LLVM=<prefix>/ and LLVM=-<suffix> select"
> +echo " the clang binary as in the kselftest build. ARCH=<arch> selects"
> +echo " the clang target architecture, defaulting to the host; it is"
> +echo " ignored for other compilers."
> echo "- Parses all test/sub-test Makefile to find library dependencies."
> echo "- Runs compile test on a trivial C file with LDLIBS specified"
> echo " in the test Makefiles to identify missing library dependencies."
> @@ -53,13 +60,32 @@ while getopts "p" arg; do
> esac
> done
>
> +# Pull an optional ARCH=<arch> out of the remaining arguments. The
> +# environment is used if it is not given on the command line, as with
> +# make.
> +args=()
> +for arg in "$@"; do
> + case "$arg" in
> + ARCH=*)
> + ARCH=${arg#ARCH=};;
> + *)
> + args+=("$arg");;
> + esac
> +done
> +set -- "${args[@]}"
> +
> if [ $# -eq 0 ]
> then
> usage
> fi
>
> # Compiler
> -CC=$1
> +case "$1" in
> + LLVM|LLVM=*)
> + setup_llvm "${1#LLVM}";;
> + *)
> + CC=$1;;
> +esac
>
> tmp_file=$(mktemp).c
> trap "rm -f $tmp_file.o $tmp_file $tmp_file.bin" EXIT
> @@ -178,6 +204,56 @@ exit $?
> }
> # end main()
>
> +# Mirror the LLVM handling in lib.mk: LLVM=<prefix>/ or LLVM=-<suffix>
> +# select the clang binary, and ARCH selects the target triple with the
> +# host as the default.
> +setup_llvm()
> +{
> + local llvm=${1#=}
> + local llvm_prefix=""
> + local llvm_suffix=""
> + local clang
> + local target
> +
> + declare -A clang_target
> + clang_target[arm]=arm-linux-gnueabi
> + clang_target[arm64]=aarch64-linux-gnu
> + clang_target[hexagon]=hexagon-linux-musl
> + clang_target[i386]=i386-linux-gnu
> + clang_target[m68k]=m68k-linux-gnu
> + clang_target[mips]=mipsel-linux-gnu
> + clang_target[powerpc]=powerpc64le-linux-gnu
> + clang_target[riscv]=riscv64-linux-gnu
> + clang_target[s390]=s390x-linux-gnu
> + clang_target[x86]=x86_64-linux-gnu
^ should this be either i386-linux-gnu or i686-linux-gnu, or does
`-m32` get set somewhere?
> + clang_target[x86_64]=x86_64-linux-gnu
> +
> + case "$llvm" in
> + */)
> + llvm_prefix=$llvm;;
> + -*)
> + llvm_suffix=$llvm;;
> + esac
> + clang=${llvm_prefix}clang${llvm_suffix}
> +
> + if [ -z "$ARCH" ]; then
> + target=$($clang -print-target-triple 2>/dev/null)
> + if [ -z "$target" ]; then
> + echo -e "\tUnable to run $clang ..."
> + exit 1
> + fi
> + else
> + target=${clang_target[$ARCH]}
> + if [ -z "$target" ]; then
> + echo -e "\tUnknown ARCH $ARCH for LLVM, supported:"
> + echo -e "\t$(echo "${!clang_target[*]}" | xargs -n1 |
> sort | xargs)"
> + exit 1
> + fi
> + fi
> +
> + CC="$clang --target=$target -fintegrated-as"
> +}
> +
> all_tests()
> {
> for test in $l1_tests; do
> @@ -285,6 +361,7 @@ print_results()
> {
> echo -e "========================================================";
> echo -e "Kselftest Dependency Check for [$0 $1 $2] results..."
> + echo -e "Compiler: $CC"
>
> if [ $print_targets -ne 0 ]
> then
>
> ---
> base-commit: 24a19b953e2a3d0ea5a8c4951a0ab8f32720c907
> base-tree: git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
> master
> change-id: 20261013-kselftest-deps-llvm-51be8d160008
>
> Best regards,
> --
> Mark Brown <[email protected]>
>
--
Thanks,
~Nick Desaulniers
