[RFC] A policy for supported ports and targets

[Bob Wilson]

Steven wrote:
> These proposals are not to bash port maintainers.  It's just as much the
> responsibility of other developers who want to move ahead with some
> improvement to help out with updating the existing ports.  But again, it
> should be the responsibility of the port maintainer to start this work.
> After all, for many targets nobody but the port maintainer knows enough
> about the internals of the port to work on it.

As the maintainer of one of the ports on your list, I'd like to add my 
perspective to the discussion.  I think your proposals sound reasonable.  I'm 
not sure if they will actually improve the situation very much, but I won't yell 
too loudly if the consensus is to adopt your new rules.

So, anyway, here is my perspective: I have a lot of other responsibilities 
besides maintaining the Xtensa port of GCC, and time is scarce.  I usually end 
up allocating my time to whatever is most urgent.  Updating the Xtensa port to 
use the new scheduler is a good example (and by the way, thanks very much for 
the work you did to update it!)  I was planning to do this work myself, but the 
old scheduler was working just fine and the Xtensa pipeline is simple enough 
that I wasn't expecting the new scheduler to provide significantly better 
results.  As you can guess, this project wasn't very high on my list of 
priorities.  There are many other similar changes that I'd like to make as soon 
as I get a chance to work on them.

One thing that would help me a lot would be an easier way of finding out about 
changes that I need to make to keep the Xtensa port well-maintained.  I spend a 
significant fraction of my time trying to keep up with this mailing list.  Even 
so, I've had a hard time finding out what the current expectations are for GCC 
ports.  Going back to the DFA scheduler example, if I had known that you were 
planning to remove it for the next release, I would have made sure to to do that 
work sooner.  If you mentioned it on the mailing list, I guess I must have 
missed it.  Since contributing the Xtensa port, I've found a number of things 
that I've needed to change to keep up with the latest standards for GCC ports. 
In almost every case, I stumbled across these things while looking at other 
ports, browsing ChangeLogs, etc.  The backends.html matrix has been helpful, I 
guess.  I'm not sure what to suggest to solve this problem.  Informative subject 
lines in messages certainly helps (e.g., "old scheduler being removed for next 
release" would get my attention).

I think it would also be reasonable to push more work onto port maintainers.  If 
someone wants to make an infrastructure change, I wouldn't mind if they sent me 
an email asking me to handle the Xtensa-specific portions.  I might not be able 
to do the work immediately, and the Xtensa port may be temporarily broken, but 
that's probably acceptable for minor ports.  I guess other port maintainers 
might disagree, but this seems like it might be a good way to balance the need 
to make infrastructure changes easier while still supporting lots of different 
ports.

--Bob