[Info-vax] The future of Ada on VMS

[gérard Calliet]

Le 24/05/2018 à 22:23, Simon Clubley a écrit :
> On 2018-05-24, gérard Calliet <gerard.calliet at pia-sofer.fr> wrote:
>> Wrong story, Simon. I never got the GNAT Ada pro, because Adacore didn't
>> want to give it anymore. VSI had a pcsi GNAT Ada pro, and at that time
>> they didn't yet unpack it, and didn't do anything for us and our
>> customer (first VSI license in the world).
>> [[About all the discution about VSI: you are totaly right, they are
>> totaly right. And Digital, Compaq, HP, HPE have always been totaly
>> right. I know it.]]
>>
> 
> Interesting. I thought you had mentioned doing it by starting with
> GNAT Pro. My mistake, sorry.
It's just the beginning of a long term conversation :)
> 
>> So we (AdaLabs, me) did rebuild the compiler from FSF sources,
>> integrating some bits of code specific to VMS from "friends" (very
>> little) and patching some code (very little). It is a canadian
>> cross-compilation operation.
>>
> 
> What are the licence terms for those bits of code ?
hum. A big world company gave some things to another company, and we got 
the sources, copyrighted by the big world company. I can't say more. 
Another personal risk. Discution with VSI could have resolve that 
officialy. But.
>
>> The limitation is that we used an old gcc because it was much simpler.
> 
> Now that's where we took a very different approach, I wanted the
> latest Ada compiler so I had to try and deal with the C++ problem
> from gcc 4.8.0 onwards. I did that by taking the Linux based cross
> compiler approach.
The best approach. But more complicated, and perhaps with not tractable 
issues. We choosed something more easy. We had a deadline.
> 
> I was also targeting VMS Alpha and it looked to me like the code
> for VMS Itanium was in better shape than that for VMS Alpha in the
> gcc and binutils versions I looked at.
I think so.
> 
>> But when  the built is done, IT IS the gnat Ada Pro : Adacore has to be
>> compliant to the license Open Source, so the sources in FSF ARE the
>> sources of Gnat Ada pro. And, of course, a lot of context tools can be
>> ported, but we didn't get time and/or investment.
>>
> 
> No they are not the same sources. Adacore maintains its own branch of
> the GNAT source code which it uses for GNAT Pro. Every so often, it
> pushes changes from this tree into the FSF tree but it is not actually
> legally required to push anything.
> 
> If you read the GPL, you will see that Adacore are only required to
> supply its customers (and only its customers) with the source code
> for the compiler those customers have bought. They are not required
> to push everything into the FSF code base.
> 
> The code bases are not identical. For example, the number of targets
> supported by GNAT Pro is larger than the number of targets supported
> by FSF GNAT.
> 
> Did ACATS pick up any issues or missing features in your Itanium compiler ?
> 
> Also, I have a good reason to ask about GPL contamination. As well as
> GNAT Pro and FSF GNAT, there is also the Community Edition directly
> available from the Adacore website.
> 
> However, any user programs compiled using this version of GNAT fall
> under the GPL because the RTL in this version of GNAT is pure GPL.
> This means that if you took anything from the RTL in the Community
> Edition of the GNAT compiler available from the Adacore website then
> that code is pure GPL and so is anything that it is inserted into.
> 
> Unlike FSF GNAT, there is no runtime exception for the Community Edition
> of the Adacore GNAT compiler.
> 
> Yes, I know it's a real mess that only makes things confusing. :-( :-(
All very interesting, and very complicated things. Thanks.
> 
> And yes, there has been much discussion about this over in the Ada world.
I'm a younger Ada guy now. I wander how my initiatives will integrate 
this world. I can say to them that I'm fighting for Ada as I'm fighting 
for VMS: two realms a little bit tired but which deserves these ighting :)
To be continued, thanks.
> 
>> With a little effort, everything is in FSF sources. I work now on dwarf
>> issues. Just beginning. I'll say more later.
>>
> 
> Simon.
> 


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