Re: TODO additions

[Dave Love <d.love@dl.ac.uk>]

Richard Stallman <rms@gnu.org> writes:

> When Autoconf handles a specific issue, it is a good idea to switch
> over to using Autoconf to handle it.  But I'd be extremely surprised
> if Autoconf handled all the issues that Emacs needs to know about.

It may not have canned tests for everything, but I don't think writing
tests where necessary and providing explicit info which can't be
tested is so difficult.  I don't see how Emacs is special, especially
compared with gcc and gdb, say (having been through this with gcc).
If a test is useful for Emacs, it's likely to be useful elsewhere.

> To implement an Autoconf test for any given issue might be easy or it
> might be hard.

Yes, but I have a fair idea what's involved, since I did a lot of it
once.

> Even when it seems easy enough to write the Autoconf
> test, verifying that it really tests the right thing is substantial
> effort.

The point is that you don't have to test everywhere.  I know that
doesn't provide real guarantees, but it's better than the current
situation, where the configuration keeps falling over on mainstream
platforms (even on GNU at least once).  There doesn't seem to be much
testing of the sort of systems I have to deal with anyhow.  I've
recently addressed issues on current versions of Solaris, Irix and
Tru64 which wouldn't have occurred with canonical autoconf.  The
Solaris issue with bcopy & al was actually the same as what I'd
already addressed specifically for Irix; using autoconf tests in that
case avoids more systems breaking that way in future.

> This is not worth the trouble, when the code is stable
> and not giving us trouble.

But the code isn't stable -- a change since the emacs-unicode branch
broke the Tru64 build -- and it's certainly still giving me trouble.
That's why I raised the topic again.