Re: i370 port

["Joseph S. Myers" <joseph at codesourcery dot com>]

On Fri, 5 Jun 2009, Paul Edwards wrote:

> It was dropped from GCC 4 when there was supposedly no
> maintainer available.  Actually, Dave Pitts and myself were
> both maintaining it at that time, but we were both still working
> on an old version of it (3.2). So gcc 3.4.6, circa 2004, was the
> last time it was included in the normal GCC distribution.

(For reference, the port was removed in SVN revision 77216; before then it 
had had various largely mechanical changes as part of changes to multiple 
back ends or target-independent code, with r69086 as the last vaguely 
i370-only change but no changes appearing to come from someone 
specifically working and testing on i370 for some years before then.  "svn 
log svn://gcc.gnu.org/svn/gcc/trunk/gcc/config/i370@77215" shows the 
history.)

> We were both maintaining it, and continue to maintain it,
> because MVS doesn't have any alternate free C compiler
> available.

To merge back into FSF GCC, the people who have made changes that would be 
merged back will need to have copyright assignments on file at the FSF 
(and disclaimers from any relevant employers).  I don't have a current 
copy of the assignments list (my very old copy does show assignments from 
David G. Pitts with an employer disclaimer dating from 1993).

> So, my question is - what is required to get the i370 port reinstated
> into the GCC mainline?

The basic requirements for a resurrected port are the same as for a new 
port; it needs to be assigned to the FSF, to pass the normal technical 
review, and the SC needs to approve someone as a maintainer of the port 
(there may be a bottleneck with the last stage, since there are currently 
at least three new ports pending approval).  It is a very good idea if you 
can run the testsuite for the port and will be posting results to 
gcc-testresults regularly.

I would encourage going through all the changes made to the i370 port on 
GCC mainline, after 3.1/3.2 branched and before the port was removed, to 
see what should be merged into your version for mainline; ultimately it 
would be up to you how you get it updated for all the mechanical changes 
on mainline since 3.2, but those changes (see command above to get logs) 
may be a useful guide to how to do some of the updates.

-- 
Joseph S. Myers
joseph@codesourcery.com