[pacman-dev] [PATCH v2 2/2] Update the question callback

[Andrew Gregory]

On 07/02/14 at 01:02am, Olivier Brunel wrote:
> On 07/02/14 00:03, Andrew Gregory wrote:
> > On 07/01/14 at 08:27pm, Olivier Brunel wrote:
> >> On 07/01/14 06:56, Allan McRae wrote:
> >>> On 29/06/14 21:35, Olivier Brunel wrote:
> >>>> On 06/29/14 03:50, Allan McRae wrote:
> >>>>> On 24/06/14 20:18, Olivier Brunel wrote:
> >>>>>> On 06/24/14 08:14, Allan McRae wrote:
> >>>>>>> On 26/05/14 01:30, Andrew Gregory wrote:
> >>>>>>>> The earlier changes to the event callback have the same issue and also
> >>>>>>>> give errors about using non-literal strings with vprintf:
> >>>>>>>>
> >>>>>>>>  testdb.c:53:11: error: format string is not a string literal
> >>>>>>>>        [-Werror,-Wformat-nonliteral]
> >>>>>>>>                  vprintf(event->fmt, event->args);
> >>>>>>>>                          ^~~~~~~~~~
> >>>>>>>
> >>>>>>> BAH!   Why did gcc no see this?
> >>>>>>>
> >>>>>>> Unless someone comes up with something else, I'll do the revert soon.
> >>>>>>
> >>>>>> I can't think of another way to silence the warning, but there's a way
> >>>>>> to "work around" it: instead of putting fmt & args inside
> >>>>>> alpm_event_log_t, we put the resulting string (i.e. call pm_asprintf()
> >>>>>> in alpm and send the resulting string in the event).
> >>>>>>
> >>>>>> No more false warnings then (but a malloc/free for each log event). I
> >>>>>> can send a patch if you'd like.
> >>>>>
> >>>>> Can not do that.   Translations of messages happen in the front-end.
> >>>>
> >>>> um, no? Translations obviously happen in ALPM, the call to gettext
> >>>> happens before calling _alpm_log(), so by then whether we send the
> >>>> message to the front-end as a pointer to the full string, or a pointer
> >>>> to a format string and a va_list, doesn't really matter.
> >>>>
> >>>> All the front-end does is decide whether or not (e.g. based on level),
> >>>> and how, to show the message to the user.
> >>>>
> >>>> Or did I not understand what you meant at all?
> >>>
> >>> Some parts are, some are not (the prefixes).  Also, pm_asprintf is not
> >>> available in the backend.
> >>
> >> I assume by prefixes you mean the front-end could add e.g. "warning:"
> >> before the message itself? Then sure, that part would be translated in
> >> the front-end, but I fail to see how getting the message as a string and
> >> not a format string & va_list would change/break anything?
> >>
> >> Either way, the front-end has no idea what the message is, nor does it
> >> care/do anything other than showing it to the user.
> >>
> >> (And pm_asprintf could simply be moved to util-common.c no?)
> >>
> >>> I am in favour of reverting the log callback as the solution here.
> >>
> >> I feel it's a little sad there isn't a way to silence this
> >> false-positive warning, since this is really all it's about.
> >>
> >> I guess the log already had its own callback separated from events,
> >> although looking at the history it seems more to be because the log_cb
> >> was created first than for any actual reason, and "merging it" into
> >> events was a good idea IMO.
> >>
> >> (Of course, if there's ever another event with such a generated
> >> string/message, it'll have to be an event, and that'll make the log
> >> stand out even more for no good reason...)
> >>
> >> I just think making it an event was a good thing, but I don't feel very
> >> strongly about this, so I guess you could just revert to a separate log
> >> callback -- though I'm curious what's the main motivation for favoring
> >> this solution? Avoiding the malloc/free calls (A buffer could also be
> >> used/printed into then, leaving the malloc only for extra-long messages) ?
> > 
> > Incorporating log messages into the event callback also silenced log
> > messages when --print is used, including debug messages, which needs
> 
> I don't understand. The commit that introduced log messages as event,
> that Allan will likely revert, shouldn't have changed anything in
> how/when said messages are printed, only how they are sent to the
> front-end (as in, which callback function is used).
> 
> Also, I just ran `pacman --debug -S --print pacman` and I see debug
> messages just fine. So I'm not sure what you mean, could you tell me how
> to reproduce it?

 void cb_event(alpm_event_t *event)
 {
 	if(config->print) {
 		return;
 	}

The only messages you see are from pacman not alpm.

apg