[LTP] [PATCH v2] syscalls/timer_getoverrun01: use kernel_timer_t type

[Jan Stancek]

On Fri, Mar 22, 2024 at 10:35 AM Petr Vorel <pvorel@suse.cz> wrote:
>
> > On Fri, Mar 22, 2024 at 6:11 AM Petr Vorel <pvorel@suse.cz> wrote:
>
> > > Hi Jan,
>
> > > ...
> > > > +++ b/testcases/kernel/syscalls/timer_getoverrun/timer_getoverrun01.c
> > > > @@ -19,10 +19,11 @@
> > > >  #include <time.h>
> > > >  #include "tst_safe_clocks.h"
> > > >  #include "lapi/syscalls.h"
> > > > +#include "lapi/common_timers.h"
>
> > > >  static void run(void)
> > > >  {
> > > > -     timer_t timer;
> > > > +     kernel_timer_t timer;
>
> > > Good catch.
> > > Reviewed-by: Petr Vorel <pvorel@suse.cz>

Pushed.

>
> > > BTW in v1 you used memset(&timer, 0, sizeof(timer_t));
> > > Could have we used with current compilers just timer_t timer = {} instead of
> > > memset()? Or what is the reason we keep using memset() instead of {}?
>
> > I treated it as opaque type. If it was a scalar, plain {} doesn't work with all
> > compilers. For example this fails to compile for me with gcc 11:
> > int main() { int i = {}; return i; }
>
> > $ gcc  -Wpedantic a.c
> > a.c: In function ‘main’:
> > a.c:1:22: warning: ISO C forbids empty initializer braces [-Wpedantic]
> >     1 | int main() { int i = {}; return i; }
> >       |                      ^
> > a.c:1:22: error: empty scalar initializer
> > a.c:1:22: note: (near initialization for ‘i’)
>
> > "{0}" should work - I guess I was just being too careful.
>
> Thanks for info, Jan. I suppose the problem is also on older
> gcc (nothing gcc 11 specific). We compile also on gcc 4.8 and 7.3.
>
> Is it also problem for older clang?

It is with clang 16:

# clang a.c
a.c:1:22: error: scalar initializer cannot be empty
int main() { int i = {}; return i; }

>
> If I understand correctly it should be safe to use {0}, and {} probably waits
> for the future.
>
> Kind regards,
> Petr
>
> > > Kind regards,
> > > Petr
>
>