Re: [PATCH] upload-pack.c: use of parse-options API

From: Antoine Queru <antoine.queru@ensimag.grenoble-inp.fr>
Date: May 19, 2016, 10:10 UTC
Message-ID: <721240639.4127450.1463652631815.JavaMail.zimbra@ensimag.grenoble-inp.fr>
In-Reply-To: <20160518180800.GC5796@sigill.intra.peff.net>

Thanks for your input.

Show 16 quoted lines

> > -static const char upload_pack_usage[] = "git upload-pack [--strict]
> > [--timeout=<n>] <dir>";
> > +static const char * const upload_pack_usage[] = {
> > +	N_("git upload-pack [--strict] [--timeout=<n>] <dir>"),
> > +	NULL
> > +};
> 
> Do we need to enumerate the options here now? The usage message should
> list the options from "struct options", which make these redundant.
> 
> Something like:
> 
>   git -upload-pack [options] <dir>
> 
> probably makes more sense.
>

Yes, you are right.

Show 19 quoted lines

> Of course, it's hard to read the usage message because...
> 
> > +	struct option options[] = {
> > +		OPT_HIDDEN_BOOL(0, "stateless-rpc", &stateless_rpc, NULL),
> > +		OPT_HIDDEN_BOOL(0, "advertise-refs", &advertise_refs, NULL),
> > +		OPT_BOOL(0, "strict", &strict, NULL),
> > +		OPT_INTEGER(0, "timeout", &timeout, NULL),
> > +		OPT_END()
> > +	};
> 
> You've left the description text for each of these options as NULL, so
> running "git-upload-pack -h" segfaults.
> 
> I'm not sure whether it is worth hiding the first two options. We
> typically hide "internal" options like this for user-facing programs, so
> as not to clutter the "-h" output. But upload-pack isn't a user-facing
> program. Anybody who is calling it directly with "-h" may be interested
> in even its more esoteric options.
>

In fact, to do this, I looked at builtin/receive-pack.c, where the parser API was already implemented, and these first two options were hidden. There were also no description for any options, so I thought it was not needed. Maybe we could update this file too ?

> As a style nit, we usually spell comparison-with-zero as just:
> 
>   if (timeout)
> 	daemon_mode = 1;

Because timeout is an int, I personnally think it is more understable to treat it as it. But I'll update itfor consistency.

Show 6 quoted lines

> > +	argc = parse_options(argc, (const char **)argv, NULL, options,
> > upload_pack_usage, 0);
> 
> Perhaps this is a good opportunity to use "const" in the declaration of
> main(), as most other git programs do. Then you can drop this cast.
>

Ok.

Show 21 quoted lines

> >  	setup_path();
> >  
> > -	dir = argv[i];
> > +	dir = argv[0];
> >  
> >  	if (!enter_repo(dir, strict))
> >  		die("'%s' does not appear to be a git repository", dir);
> 
> Prior to your patch, we used to check:
> 
>   -       if (i != argc-1)
>   -               usage(upload_pack_usage);
> 
> which ensured that "dir" was non-NULL. But with your patch, we may pass
> NULL to enter_repo. It fortunately catches this, but then we pass the
> NULL to die, which can segfault (though on glibc systems, stdio is kind
> enough to replace it with the "(null)").
> 
> Related, we silently accept extra arguments after your patch (whereas
> before we showed the usage message). You probably want to check "argc ==
> 1", and otherwise show the usage message.

Ok.

-Antoine