Re: MS-Windows build using Posix configury

[Glenn Morris <rgm@gnu.org>]

Eli Zaretskii wrote:

> 'ln' does work on Windows, but evidently not good enough for Autoconf.

Sounds like an autoconf bug that should be reported.

> And indeed, the Windows documentation clearly says that hard links to
> directories are not supported.
>
> I could, of course, force LN_S to be 'ln' for the Windows build, but
> then what if one day we will need to make a hard link to a directory?

This isn't portable, so we should never do this.
For example, on the AFS file system, hard links cannot span directories.
We should only ever use links in the way that we currently do, between
files in the same directory. From the autoconf manual:

     If you make a link in a directory other than the current
     directory, its meaning depends on whether `ln' or `ln -s' is used.
     To safely create links using `$(LN_S)', either find out which form
     is used and adjust the arguments, or always invoke `ln' in the
     directory where the link is to be created.

So it is totally fine for you to just set LN_S=ln on MS Windows until
autoconf gets fixed to do this anyway.

> OTOH, Paul suggested to use 'ln' on all platforms when installing
> Emacs (which is the only place where this issue arises), in which case
> this is a moot point.

I already said that symlinks are better here IMO.
http://lists.gnu.org/archive/html/emacs-devel/2013-04/msg00230.html

> On the third hand, there's talk about not creating any links as part
> of "make install" (see
> http://lists.gnu.org/archive/html/emacs-devel/2013-04/msg00450.html).

We'll always have the emacs-XX.YY -> emacs link.

> So I'm not sure this is worth any effort.

The least effort, and the right thing IMO is for you to just set
LN_S=ln. If ln works, we never want to use "cp -p".