Re: [PATCH 4/4] coccicheck: add indexing enhancement options

[Julia Lawall]

On Wed, 15 Jun 2016, Luis R. Rodriguez wrote:

> On Tue, Jun 14, 2016 at 11:17:13PM +0200, Julia Lawall wrote:
> >
> >
> > On Tue, 14 Jun 2016, Luis R. Rodriguez wrote:
> >
> > > On Tue, Jun 14, 2016 at 10:47:32PM +0200, Julia Lawall wrote:
> > > >
> > > >
> > > > On Tue, 14 Jun 2016, Luis R. Rodriguez wrote:
> > > >
> > > > > On Tue, Jun 14, 2016 at 07:22:03AM +0200, Julia Lawall wrote:
> > > > > >
> > > > > >
> > > > > > On Mon, 13 Jun 2016, Luis R. Rodriguez wrote:
> > > > > >
> > > > > > > On Mon, Jun 13, 2016 at 09:50:15PM +0200, Julia Lawall wrote:
> > > > > > > >
> > > > > > > >
> > > > > > > > On Mon, 13 Jun 2016, Luis R. Rodriguez wrote:
> > > > > > > > >
> > > > > > > > > I'll redirect stderr to stdout by default when parmap support is used then.
> > > > > > > >
> > > > > > > > Usually I put them in different files.
> > > > > > >
> > > > > > > We can do that as well but I would only want to deal with parmap support
> > > > > > > case. Any preference? How about .coccicheck.stderr.$PID where PID would
> > > > > > > be the PID of the shell script?
> > > > > >
> > > > > > I don't understand the connection with parmap.
> > > > >
> > > > > When parmap support is not available the cocciscript will currently
> > > > > disregard stderr, output is provided as it comes to stdout from each
> > > > > thread I guess.
> > > >
> > > > Deepa's recent patch to coccicheck made apparent that Coccicheck uses
> > > > --very-quiet, so there is standard error.
> > >
> > > OK I'm disegarding the redirect for non-parmap for now but we'd have to
> > > determine if we want to append or add one per PID... I rather leave that
> > > stuff as-is and encourage folks to upgrade coccinelle.
> >
> > If coccicheck is using --very-quiet, there will not be much stderr of
> > interest when using parmap either.
>
> OK I don't follow. Does coccinelle only direct error to stderr when --very-quiet
> is used ? Or does using --very-quiet suppress stderr ?

--very-quiet suppresses most administrative messages that go to stderr.
There are still actual errors.  Bu you don't see eg what file is being
currently processed.

> > > > > > Originally our use of parmap made output, specia files based on pids.  Maybe this
> > > > > > is the default for parmap.  I found this completely unusable.  I guess one
> > > > > > could look at the dates to see which file is the most recent one, but it
> > > > > > seems tedious.  If you are putting the standard output in x.out, then put
> > > > > > the standard error in x.err.
> > > > >
> > > > > I'll use ${DIR}/coccicheck.$$.err for stderr.
> > > >
> > > > What is ${DIR}? and what is $$?
> > >
> > > When you run scripts/coccicheck we take the absolute directory
> > > of it and then go down one level of directory, so in this case it
> > > would be the base directory of the Linux kernel.
> > >
> > > $$ is the PID of the bash script.
> >
> > OK.  I still don't find PIDs useful, but I guess if we are talking about
> > the entire output of coccicheck, there is not much else to do.  Normally,
> > I don't want these files accumulating, and just write over the old ones.
>
> Which is why I would much prefer to instead just redirect in coccicheck
> case stderr to stdout from coccinelle. Is that preferred?

Then things will be merged in strange ways.

Why not just let the user decide what to do with these things?

julia