[Info-vax] The future of Ada on VMS

[johnwallace4 at yahoo.co.uk]

On Thursday, 24 May 2018 14:46:01 UTC+1, gérard Calliet  wrote:
> > 
> > Your effort so far in building the Open source GNAT ADA compiler on OpenVMS appears to me to be the option that has made the most progress so it seems strange that VSI won't pursue this.
> > 
> The best summary I read.
> 
> I think VSI has a lot of difficulties dealing with the Open Source 
> strategies.
> 
> Understandable in a culture of "everything is under control" (which is 
> good).
> 
> But they don't understand that the survival of VMS depends sometimes on 
> best effort strategies, and that Open Source could be a very good 
> solution in specific cases, if the limits are known.
> 
> They have to be more relax, and more opened to all efforts in the 
> community. The way they manage Open Source projects on which they are 
> doing (often very good) work is also problematic : not very opened, not 
> very integrated in the Open Sources communities. And I think there is 
> there also a cultural issue.
> 
> About Ada, yes we hope we'll make other progresses, and perhaps VSI will 
> understand we are more relax than they imagine about collaboration: 
> sometimes, a little (mutual) help is worth it, without necessecity of 
> stone contracts.
> 
> Gérard Calliet
> 
> ---
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> https://www.avast.com/antivirus

Gerard, with greatest respect, I still don't 
understand exactly who is expecting to provide 
what facilities to who in the picture you 
described, let alone what (if any) commercial 
implications might be involved.

Is there a different description somewhere else,
perhaps with some background information on
why VSI might expect this to be financially 
significant enough for them to devote resources
to it? (Why does it have to be VSI?)

I have spent several decades on and off working
with people doing variants on this kind of 
thing, developing on VMS and elsewhere, 
targeting VMS and elsewhere, targeting DEC and 
non-DEC kit, some using 'pure Ada' for design
reasons and some using Ada as an 'intermediate
language' because it's what's in the contract.
 
I don't get out much these days, but questions 
that might help me (and/or VSI) understand the 
vision might include:

Where (e.g. what OS) do the Ada developers sit? 
On VMS, on a Linux box, on a Window box?

Where does the application run? On VMS? On
'bare metal' ? Some other environment?

What does the Ada source code look like?
Is it user coded from scratch or is it 
autogenerated by a higher level tool, e.g.
some kind of "Model Based Systems Engineering"
tool which uses Ada output as a contractual
obligation rather than another important part
of the design verification chain.

Is it pure Ada? Pure Ada plus calls to 
libraries (and if so, which)? Pure Ada plus 
libraries with system services (and if so, 
which target OS, and which particular 
services)?

Without knowing those answers, it's hard
to understand what will be required.

Regardless of those answers...
I've also spent an embarrassing amount of time
working with, maintaining (and occasionally 
rewriting) software test and validation tools 
and runtime environments for safety critical 
code and such, with object+debug formats from 
COFF/STABS in the 1980s through to ELF/DWARF
more recently, and various instruction sets 
and runtimes too. Most recently, when I was 
trying to work with DWARF output from gnat, 
DWARF itself was a bit of a challenge, but any 
non-trivial use with output of Ada compilations 
seemed to require far too much knowledge of 
obscure gnat internals (e.g. use of 'proprietary' 
name-mangling conventions instead of facilities 
defined in the DWARF V3 standard). Maybe that's 
changed.

Basically, there's a lot of work here. Most
of it isn't really related to 'open source'
or even to VSIVMS's (lack of) standards 
compliance (e.g. POSIX). 

How much of it needs to be done ASAP to 
keep VMS in this picture? Which parts 
of the picture need VMS and/or VSI 
involvement? How much can other folks 
deliver with advice from experts elsewhere?

Most of those questions are backward-facing.
Some of the answers might be different five
years from now. The costs and timescales 
and commercial implications of anything
which results will depend on who 'owns'
the various pieces of whatever the end
product turns out to be.


Predictions are hard at the best of times.



Further enlightenment very welcome.