Re: master 32fe187bdf1: Install rcs2log within Emacs packages for Android

[Eli Zaretskii <eliz@gnu.org>]

> From: Po Lu <luangruo@yahoo.com>
> Cc: emacs-devel@gnu.org
> Date: Thu, 24 Aug 2023 16:42:44 +0800
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> >>     * src/callproc.c (syms_of_callproc) <Vrcs2log_program_name>: New
> >>     defvar.  Define to `librcs2log.so' under Android, `rcs2log'
> >
> > Why do we need this variable defined and initialized in C?  Can't we
> > do that in Lisp instead?  Since vc-rcs.el needs it, can't the variable
> > be defined there, for example?
> 
> We do this for consistency with the other -program-name variables for
> programs within exec-directory.

Those other variables should be moved out of there as well, IMO.  They
are recent additions, AFAIU as part of the Android merge.  I see no
reason to have them defined in C, as they are not invoked from any C
code, are they?

> Moreover, Lisp other than vc-rcs.el may want to use rcs2log: it
> helps to have its name defined in a central location, instead of
> forcing everyone to either require vc or duplicate the definition
> within syms_of_callproc.

OK, then let's have them in simple.el or in files.el.  Or any other
preloaded Lisp, if those two don't sound appropriate.