[igt-dev] [PATH i-g-t 2/2] core: Show backtrace from igt_skip_on_simulation

[Daniel Vetter]

On Fri, Sep 14, 2018 at 10:19:29AM +0100, Tvrtko Ursulin wrote:
> 
> On 14/09/2018 10:12, Daniel Vetter wrote:
> > On Wed, Sep 12, 2018 at 10:33:06AM +0100, Tvrtko Ursulin wrote:
> > > From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> > > 
> > > igt_skip_on_simulation is called both directly from tests but also from
> > > library helpers. In the latter case especially the logged caller name is
> > > useless since it is always the helper itself. What we instead want to know
> > > is who is the caller.
> > > 
> > > Trivial approach would be to move the helper to a header as static inline,
> > > but due the longjmp in it it can never be inlined. Alternative option is
> > > to print a backtrace from it.
> > > 
> > > Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> > > Cc: Radoslaw Szwichtenberg <radoslaw.szwichtenberg at intel.com>
> > > ---
> > >   lib/igt_core.c | 20 ++++++++++++++++----
> > >   1 file changed, 16 insertions(+), 4 deletions(-)
> > > 
> > > diff --git a/lib/igt_core.c b/lib/igt_core.c
> > > index 23bb858fd886..990abc5a36b3 100644
> > > --- a/lib/igt_core.c
> > > +++ b/lib/igt_core.c
> > > @@ -2065,14 +2065,26 @@ bool igt_run_in_simulation(void)
> > >    */
> > >   void igt_skip_on_simulation(void)
> > >   {
> > > +	bool in_simulation;
> > > +
> > >   	if (igt_only_list_subtests())
> > >   		return;
> > > +	in_simulation = igt_run_in_simulation();
> > > +
> > >   	if (!igt_can_fail()) {
> > > -		igt_fixture
> > > -			igt_require(!igt_run_in_simulation());
> > > -	} else
> > > -		igt_require(!igt_run_in_simulation());
> > > +		igt_fixture {
> > > +			if (in_simulation) {
> > > +				print_backtrace();
> > > +				igt_require(!in_simulation);
> > > +			}
> > > +		}
> > > +	} else {
> > > +		if (in_simulation) {
> > > +			print_backtrace();
> > > +			igt_require(!in_simulation);
> > 
> > Hm, why don't we go right ahead and push this into igt_skip()? There's a
> > pile of other igt_require, and we tend to push a lot of these into the
> > library. So they have all the same problem.
> 
> Maybe.. I wasn't 100% this was a good idea to start with, or in another
> words, that other people would consider it a problem. Since the downside is
> test output gets more verbose on skips, or some could say more noisy.
> 
> So I basically floated the patch to see if it will provoke some responses.
> :)

We have the backtrace already in igt_fail, makes total sense to add it to
igt_skip too. Has my ack at least.

Aside: I kinda wonder whether we need an __igt_require, which embeds the
if (igt_can_fail) igt_require() else igt_fixture igt_require() thing. But
that's just an aside.

Cheers, Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch