Re: [PATCH] selftests/nolibc: add 7 tests for memcmp()

[Willy Tarreau <w@1wt.eu>]

On Fri, Oct 21, 2022 at 10:07:38AM -0700, Paul E. McKenney wrote:
> > I see. In the worst case, a preliminary "make clean" will do it. We just
> > need to decide what's the best solution for everyone (i.e. not waste too
> > much time between tests while not getting misleading results by accident).
> 
> Maybe just document the careful/slow way, then people doing it more
> frequently can do it the clever/fast way.
> 
> My guess is that the careful/slow is this:
> 
> 	pushd tools/include/nolibc
> 	make clean
> 	make
> 	popd
> 	pushd tools/testing/selftests/nolibc
> 	make clean
> 	make -j32 run
> 
> Or did I miss a turn in there somewhere?

It's even easier, you don't even need the clean phase in include/nolibc.
I'm doing this and it's sufficient:

  make -C tools/testing/selftests/nolibc clean
  make -C tools/testing/selftests/nolibc nolibc-test
  tools/testing/selftests/nolibc/nolibc-test

Or for the test under QEMU, which involves a kernel build:

  make -C tools/testing/selftests/nolibc clean
  make -C tools/testing/selftests/nolibc -j $(nproc) run

Where would you first look for such a hint ? Maybe the help output of
the default "make" command could send as a hint that a clean is needed
after patching nolibc and that could be sufficient ? I just want to make
sure users don't waste their time trying to find what they could be doing
wrong.

Willy