First of all, in order to build with clang at all, one must first apply Valentin Obst's build fix for LLVM [1]. Once that is done, then when building with clang, via:

make LLVM=1 -C tools/testing/selftests

...the following error occurs:

clang: error: cannot specify -o when generating multiple output files

This is because clang, unlike gcc, won't accept invocations of this form:

clang file1.c header2.h

While trying to fix this, I noticed that:

a) selftests/lib.mk already avoids the problem, and

b) The binderfs Makefile indavertently bypasses the selftests/lib.mk build system, and quitely uses Make's implicit build rules for .c files instead.

The Makefile attempts to set up both a dependency and a source file, neither of which was needed, because lib.mk is able to automatically handle both. This line:

binderfs_test: binderfs_test.c

...causes Make's implicit rules to run, which builds binderfs_test without ever looking at lib.mk.

Fix this by simply deleting the "binderfs_test:" Makefile target and letting lib.mk handle it instead.

[1] https://lore.kernel.org/all/20240329-selftests-libmk-llvm-rfc-v1-1-2f9ed7d1c...

Fixes: 6e29225af902 ("binderfs: port tests to test harness infrastructure") Cc: Christian Brauner brauner@kernel.org Signed-off-by: John Hubbard jhubbard@nvidia.com --- tools/testing/selftests/filesystems/binderfs/Makefile | 2 -- 1 file changed, 2 deletions(-)

diff --git a/tools/testing/selftests/filesystems/binderfs/Makefile b/tools/testing/selftests/filesystems/binderfs/Makefile index c2f7cef919c0..eb4c3b411934 100644 --- a/tools/testing/selftests/filesystems/binderfs/Makefile +++ b/tools/testing/selftests/filesystems/binderfs/Makefile @@ -3,6 +3,4 @@ CFLAGS += $(KHDR_INCLUDES) -pthread TEST_GEN_PROGS := binderfs_test

-binderfs_test: binderfs_test.c ../../kselftest.h ../../kselftest_harness.h - include ../../lib.mk

base-commit: f03359bca01bf4372cf2c118cd9a987a5951b1c8 prerequisite-patch-id: b901ece2a5b78503e2fb5480f20e304d36a0ea27