Re: Upstreaming very old changes

[Jeff Law <law at redhat dot com>]

On 08/04/2017 11:20 AM, coypu@sdf.org wrote:
> Hi, GCC!
> 
> I believe netbsd is the primary user of the vax target. its status is:
> 
> good: netbsd uses gcc 5.4.0, and cross compiles its userland+kernel with
> this. it runs and is also able to natively build useful programs like perl.
> 
> bad: -O0 in places, text relocations. obvious signs of more bugs not yet
> investigated.
> 
> however, this is with a large diff to gcc. the author of most of the
> changes is Matt Thomas, who is also the GCC vax port maintainer. the
> biggest change is probably shared library support (... from 1998).
> 
> I'm not sure why he hasn't committed his work upstream, but it would be
> nice to bridge the gap, to make it easier for anyone (possibly myself,
> in some future time after education) to adapt the code to non-deprecated
> GCC APIs.
> 
> legal - I don't think this is a real issue - most people involved have
> already signed FSF paperwork, and there's commit history, so I can
> explicitly ask all the people involved to state they are OK with it.
> 
> technical - I am not a compiler expert, and this is a large unexplained
> diff. even originally, the commit messages weren't very verbose. It also
> adds 20 years of effectively "merge local diff to head". however, the
> end result does work well enough to boot, run, etc.
> 
> if I go down this road, how can I begin bridging this gap?
Best advice is to break things down into a series of independent
changes.  Ideally with testcases.

Jeff