Re: [PATCH v3] trace2: refactor to avoid gcc warning under -O3

> Jeff King <peff@peff.net> writes:
> 
> >> @@ -287,7 +285,7 @@ static int tr2_dst_try_unix_domain_socket(struct tr2_dst *dst,
> >>  	if (tr2_dst_want_warning())
> >>  		warning("trace2: could not connect to socket '%s' for '%s' tracing: %s",
> >>  			path, tr2_sysenv_display_name(dst->sysenv_var),
> >> -			strerror(e));
> >> +			strerror(errno));
> >
> > We expect the value of errno to persist across tr2_dst_want_warning()
> > and tr2_sysenv_display_name() here. The former may call getenv() and
> > atoi(). I think that's probably fine, but if we wanted to be really
> > paranoid, we'd have to preserve errno manually here, too.
> 
> Being "really paranoid" consistently within the file would mean a
> change like the attached, I would think, on top of what was posted.
> 
> Or tr2_dst_want_warning() and tr2_sysenv_display_name() can be
> taught to preserve errno like tr2_dst_dry_uds_connect() was taught
> to do so by the patch under discussion, which may reduce the amount
> of apparent change, but constantly moving the contents of errno
> around just in case we later might want to use its value feels
> dirty.
> 
> I dunno.
> 
>  trace2/tr2_dst.c | 14 +++++++++++---
>  1 file changed, 11 insertions(+), 3 deletions(-)