runner: Add support for code coverage

The gcc compiler has a feature that enables checking the code coverage
in runtime[1].

[1] See https://www.kernel.org/doc/html/latest/dev-tools/gcov.html

The Linux Kernel comes with an option to enable such feature:

	./scripts/config -e DEBUG_FS -e GCOV_KERNEL

The driver's Makefile also needs change to enable it. For instance, in
order to enable GCOV for all DRM drivers, one would need to run:

	for i in $(find drivers/gpu/drm/ -name Makefile); do
                sed '1 a GCOV_PROFILE := y' -i $i
        done

This patch adds support for it by:

a) Implementing a logic to cleanup the code coverage counters via sysfs;
b) Calling a script responsible for collecging code coverage data.

The implementation works with two modes:

1) It zeroes the counters, run all IGT tests and collects the code
   coverage results at the end.

   This implies that no tests would crash the driver, as otherwise the
   results won't be collected;

   This is faster, as collecting code coverage data can take several
   seconds.

2) For each test, it will clean the code coverage counters, run the and
   collect the results.

   This is more reliable, as a Kernel crash/OOPS won't affect the
   results of the previously ran tests.

Reviewed-by: Petri Latvala <petri.latvala@intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

0 files changed, 0 insertions, 0 deletions