Re: Very elementry query

Re: Very elementry query

[Gisle S�lensminde]

In article <7vn60o$6km$1@nnrp1.deja.com>, rishikeshjha@my-deja.com wrote:
>Hi gurus,
>
>I am an absolute newbie to ADA. I have been assigned the task of sizing
>a project wherein a ADA app. has to be ported from Solaris to NT. Can
>someone tell me how complicated such efforts are.
>
>I know this question is severly lacking in detail but then I need a
>very appx answer too.
>
>TIA (and thanks for your patience too ;-) )
>Rishikesh Jha
>GGN

It depends. If the application is written in standard Ada (83 or 95),
and it don't use any compiler or platform specific libraries, it should
be straightforward. Since Solaris normally don't give direct access
to the hardware, problems due to that is not likely.

It the program contains compiler specific extensions, and these
extensions don't exists on your compiler on NT, there will be 
more or less porting. If the program use any platform specific 
libraries, you will need to port or rewrite parts of the program.
If such libraries are isolated to a part of the program or a module,
that will ease the porting.

To be able to give a more precise answer we need to know the following:

  - The Ada compiler used at the Sun computer. 
  - The Ada compiler you want to use in NT. 
  - Is it Ada 83 or Ada 95 ?
  - Does the program use any platform or compiler specific libraries ?
  - Does the program depend upon any compiler specific language extensions?

--
Gisle S�lensminde ( gisle@ii.uib.no )   

Re: Very elementry query

[Marin David Condic]

rishikeshjha@my-deja.com wrote:

> I am an absolute newbie to ADA. I have been assigned the task of sizing
> a project wherein a ADA app. has to be ported from Solaris to NT. Can
> someone tell me how complicated such efforts are.
>

Please note that the language is "Ada" - named after Ada Byron and not
"ADA" (Americans with Disabilities Act? American Dental Association?). For
some reason we have a tendancy to be touchy about this. :-)

I don't think your problems are going to be Ada specific. My experience in
porting Ada between PC's and Unix has been very positive. But then, the
applications were simple command-line-interface driven and made little to
no system calls. Given that GNAT exists on both platforms, I found that
compilation had zero problems and things ran mostly identically. (Some
problems with byte sex differences in external, custom built data files,
but this may be avoided if the Ada code is structured to detect this
possibility.) With a large number of applications I've built/ported, the
effort was near zero - just recompile and go.

Your real problem is going to be in the area of OS dependencies. You will
want to assess how much of the application performs GUI functions, asks for
OS services, manipulates files with unusual design, etc. That's the code
you will need to worry about and the level of porting effort will depend on
the skill of the programmers, the portability/isolation of the original
design and so on.

If it were me, I'd assess what portion of the app has such sensitive
features and count up the SLOCs. Anything that does more or less general
computational stuff ought to port very easily. Since our organization has
several years of productivity data (counting SLOCs per fortnight) I could
take a SWAG at how many hours would be needed to review/rewrite that
portion of code which may be bound to the OS. If you have similar data for
your organization, this would be a major help. (There is no way that one
organization's productivity measures will have anything to do with another
organization's behavior, so it wouldn't be much use for me to share that
data)

If you have more information about the nature of the app, and you are free
to post it here, its possible you may get more helpful answers.

MDC
--
Marin David Condic
If you act quick, you may still find me at.......
Real Time & Embedded Systems, Propulsion Systems Analysis
United Technologies, Pratt & Whitney, Large Military Engines
M/S 731-95, P.O.B. 109600, West Palm Beach, FL, 33410-9600
***To reply, remove "bogon" from the domain name.***

Visit my web page at: http://www.mcondic.com/

Very elementry query

[rishikeshjha]

Hi gurus,

I am an absolute newbie to ADA. I have been assigned the task of sizing
a project wherein a ADA app. has to be ported from Solaris to NT. Can
someone tell me how complicated such efforts are.

I know this question is severly lacking in detail but then I need a
very appx answer too.

TIA (and thanks for your patience too ;-) )
Rishikesh Jha
GGN


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Re: Very elementry query

[Ted Dennison]

In article <7vn60o$6km$1@nnrp1.deja.com>,
  rishikeshjha@my-deja.com wrote:
> I am an absolute newbie to ADA. I have been assigned the task of
> sizing a project wherein a ADA app. has to be ported from Solaris to
> NT. Can someone tell me how complicated such efforts are.
>
> I know this question is severly lacking in detail but then I need a
> very appx answer too.

Ada itself is farily portable. So its quite possible it will be *no*
work, just a matter of recompiling the software. But of course any OS
calls made outside the language, or compiler specific features used will
be a fair bit of work to port. And there's also the related issue of
porting from Ada 83 to Ada 95, which may come up. So the answer really
has everything with how the code in question is written and what it
does.

My suggestion would be to hook up with an Ada vendor or two and ask for
their help in this estimate. Most of them have a lot of experience with
these issues.

Failing that, you'll have to go through the source youself, looking for
unportable things, with an eye towards how much redesign will be
required to get them working on the new platform. We here on c.l.a can
certianly be of help if you have specific "Is this construct guaranteed
portable?" or "How can I accomplish this in Ada on NT?" questions.

But of course no one here is going to be able to just tell you "200
hours". :-)

--
T.E.D.


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