Re: [PATCH 3/3] kunit: test: Drop CONFIG_MODULE ifdeffery

[Petr Pavlu <petr.pavlu@suse.com>]

On 6/12/25 4:53 PM, Thomas Weißschuh wrote:
> The function stubs exposed by module.h allow the code to compile properly
> without the ifdeffery. The generated object code stays the same, as the
> compiler can optimize away all the dead code.
> As the code is still typechecked developer errors can be detected faster.
> 
> Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>

I'm worried that patches #2 and #3 make the code harder to understand
because they hide what is compiled and when.

Normally, '#ifdef CONFIG_XYZ' or IS_ENABLED(CONFIG_XYZ) directly
surrounds functionality that should be conditional. This makes it clear
what is used and when.

The patches obscure whether, for instance, kunit_module_notify() in
lib/kunit/test.c is actually used and present in the resulting binary
behind several steps. Understanding its usage requires tracing the code
from kunit_module_notify() to the definition of kunit_mod_nb, then to
the register_module_notifier() call, and finally depends on an ifdef in
another file, include/linux/module.h.

Is this really better? Are there places where this pattern is already
used? Does it actually help in practice, considering that CONFIG_MODULES
is enabled in most cases?

-- 
Thanks,
Petr