Re: [PATCH v4] sysdeps/nanosleep: Use clock_nanosleep_time64 if avaliable

[Paul Eggert <eggert at cs dot ucla dot edu>]

On 11/6/19 10:01 AM, Alistair Francis wrote:
> > > +  ts32 = valid_timespec64_to_timespec (*req);
> > The man pages for clock_nanosleep (e.g. [2], [3]) do not mention about
> > the possibility to have *req equal to NULL, hence I do assume that we
> > don't need to do it here as well...
> I really don't like accessing a pointer without first checking it.
> __clock_nanosleep is going to be called from inside glibc so I think
> it makes sense to keep the check in.

Sorry, I'm not understanding this part of the discussion. req is a 
pointer to a structure, so I assumed that "*req equal to NULL" was 
intended to read "req equal to NULL" and Lukasz was commenting that he 
was assuming that the code was correct as-is and does not need a "req != 
NULL" test. But your reply makes it sound like there's already such a 
test, which is not something that I see in the proposed patch.

As I understand it, the glibc tradition generally is as Lukasz 
suggested, in that if there's no requirement to check for null pointers 
we generally don't add one. (Of course there are exceptions for 
historical reasons etc.)