Re: Dynamic module building and reloading

[Eli Zaretskii <eliz@gnu.org>]

> From: Nicolas Martyanoff <nicolas@n16f.net>
> Date: Tue, 13 Jun 2023 18:11:47 +0200
> 
> 1. There does not seem to be any builtin utilities to deal with
> the process of building and loading shared library. I ended up writing a
> couple elisp functions to find the location of the C file, spawn cc,
> load the shared library… Is this the expected method? In this state, it
> would seem that every Emacs packages using dynamic modules has to write
> its own build/load code.

The expected method of building a shared library is the same as you'd
use for building any other shared library out there.  The Emacs
modules aren't special in any way, and the details of their build
procedures depend on what code you are compiling in, which other
libraries you need to link against, etc.  There's no way an Emacs
command could cover all that.  However, if you write a Makefile to
compile and link the module, you can use "M-x compile" to run the Make
utility to build your module.

> 2. It seems that once a dynamic module has been loaded, it cannot be
> reloaded after the shared library has been rebuilt. A Google search
> seems to confirm it. Is there a workaround? If I pursue my little
> project, I'll have to write quite a lot of C code in the dynamic module;
> I *really* do not want to restart Emacs to test every single
> modification.

We don't have a facility to unload a module, no.  The usual way of
testing your development code is to start a new scratch session (in
addition to your production Emacs session) each time you recompile a
module.