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-v1-1-2f9ed7d1c49f@valentinobst.de/
Fixes: 6e29225af9 ("binderfs: port tests to test harness infrastructure")
Cc: Christian Brauner <brauner@kernel.org>
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
019baf635e