Re: [PATCH] Project out of sources compilation

[Eli Zaretskii <eliz@gnu.org>]

> From: Konstantin Kharlamov <Hi-Angel@yandex.ru>
> Cc: rms@gnu.org, spacibba@aol.com, dmitry@gutov.dev, emacs-devel@gnu.org
> Date: Wed, 03 Apr 2024 16:31:30 +0300
> 
> On Wed, 2024-04-03 at 14:45 +0300, Eli Zaretskii wrote:
> > > From: Konstantin Kharlamov <Hi-Angel@yandex.ru>
> > > Cc: dmitry@gutov.dev, emacs-devel@gnu.org
> > > Date: Wed, 03 Apr 2024 13:40:59 +0300
> > > 
> > > 1: Emacs does not fully support it though, because while object
> > > files
> > > and configs do end up inside `build`, however `*.elc` files are
> > > still
> > > scattered all over the repo. But I hope you get the idea.
> > 
> > The *.elc files are considered part of the source tree (they are in
> > the release tarball, and are portable, so no need to rebuild them
> > when
> > changing some configuration options).  
> 
> They are generated during compilation and are not commited into git. 
> That makes them build artifacts.

How is this relevant to whether or not Emacs supports out of tree
builds?  Building from Git is a special kind of activity; it has its
own INSTALL file and _must_ build some of the files in the source
tree.  Are you aware of many projects whose build from Git can be done
without first populating the source tree with some files?  Heck, you
don't even have the configure script when you clone the repository,
and out-of-tree build works by invoking the configure script from a
directory _other_ than the one where the script lives.  Right?

> The fact they're distributed in release tarballs does not make it
> less true.  Distributing them in tarballs is not strictly necessary,
> exactly because they can be generated by anyone.

Not true.

> Having .elc files in the source tree results in problems when a user
> created a dir `build-feature1` for one feature branch, and a dir
> `build-feature2` for another; and then `build-feature1` somehow ends up
> having "feature2".  Which is because it's using build artifacts that
> are outside `build-feature1`.

Again, not relevant to the aspect on which I commented.

> Thus, Emacs certainly does not fully support "out of tree" builds.

It does.  You are just talking about a very different kind of "out of
tree build".