Re: Add comments for a postgres program in bootstrap mode

Hello folks,

On Fri, Sep 27, 2019 at 1:59 PM Amit Langote <amitlangote09(at)gmail(dot)com> wrote:
>
> On Fri, Sep 27, 2019 at 12:52 PM Youki Shiraishi <shiraishi(at)computer(dot)org> wrote:
> > On Fri, Sep 27, 2019 at 12:10 AM Amit Langote <amitlangote09(at)gmail(dot)com> wrote:
> > > On Thu, Sep 26, 2019 at 6:32 PM Youki Shiraishi <shiraishi(at)computer(dot)org> wrote:
> > > > On Thu, Sep 26, 2019 at 5:38 PM Amit Langote <amitlangote09(at)gmail(dot)com> wrote:
> > > > > + /* Bootstrap mode for initdb */
> > > > > if (argc > 1 && strcmp(argv[1], "--boot") == 0)
> > > > > AuxiliaryProcessMain(argc, argv); /* does not return */
> > > > > else if (argc > 1 && strcmp(argv[1], "--describe-config") == 0)
> > > > >
> > > > > How about expanding that comment just a little bit, say:
> > > > >
> > > > > /*
> > > > > * Bootstrapping is handled by AuxiliaryProcessMain() for historic
> > > > > * reasons.
> > > > > */
> > >
> > > Do you any thoughts on this suggestion?
> >
> > Sorry, I missed your suggestion.
> > The purpose of a comment here is to direct hackers to initdb.c because
> > the --boot option is used only by initdb.
> > initdb.c describes why it uses the --boot option (i.e., historical
> > reason), so I think it should not be described in main.c.
>
> Sorry, I didn't really mean to take out the "for initdb" part. So, I
> should've suggested this
>
> /*
> * Bootstrap mode for initdb. Bootstrapping is handled by
> * AuxiliaryProcessMain() for historical reasons.
> */
>
> IMO, it would be good for this comment to say why
> AuxiliaryProcessMain() is invoked here instead of, say,
> PostgresMain(). "for historical reasons" may not be enough but maybe
> it is.

I totally agree with that.
It might also help to tell that AuxiliaryProcessMain() is special
entry point compared to others.

According to the discussion so far, I revised my patch as attached.
I believe the patch might help beginners.

Many thanks,

--
Youki Shiraishi
NTT Software Innovation Center
Phone: +81-(0)3-5860-5115
Email: shiraishi(at)computer(dot)org