[Intel-gfx] [PATCH i-g-t 1/3] lib/core: Avoid unused result in backtrace printing

[Chris Wilson]

Quoting Tvrtko Ursulin (2017-11-03 12:04:15)
> 
> On 03/11/2017 11:52, Chris Wilson wrote:
> > Quoting Tvrtko Ursulin (2017-11-03 11:47:54)
> >> From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> >>
> >> Add helpers for direct write to stderr to consolidate the code
> >> and avoid the unused result warning in build.
> >>
> >> Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> >> ---
> >>   lib/igt_core.c | 23 ++++++++++++++++-------
> >>   1 file changed, 16 insertions(+), 7 deletions(-)
> >>
> >> diff --git a/lib/igt_core.c b/lib/igt_core.c
> >> index 538a4472e209..351859eaa04c 100644
> >> --- a/lib/igt_core.c
> >> +++ b/lib/igt_core.c
> >> @@ -1239,7 +1239,7 @@ static const char hex[] = "0123456789abcdef";
> >>   static void
> >>   xputch(int c)
> >>   {
> >> -       write(STDERR_FILENO, (const void *) &c, 1);
> >> +       igt_assert_eq(write(STDERR_FILENO, (const void *) &c, 1), 1);
> > 
> > Infinite recursion, you can't use an assert from inside the assert
> > handler.
> 
> I thought it is the signal handler. Tested sending some signals and it 
> survived. If there is a flaw there could instead nerf them with void 
> cast, don't know.

I do recall these are meant to be fail safe, so using something like
assert which may end up here again is no-no. igt_ignore_warn()?
-Chris