Public Domain Ada83 for Windows NT

Public Domain Ada83 for Windows NT

[Colin James 0621]

  
What is necessary to obtain, by ftp or otherwise, and from where exactly,
for building a public domain type Ada83 compiler for Windows NT?
  
Thanks in advance for any info.
  

Re: Public Domain Ada83 for Windows NT

[Michael Feldman]

In article <9307242022.aa24198@dsc.blm.gov> cjames@DSC.BLM.GOV (Colin James 062
1) writes:
>
>  
>What is necessary to obtain, by ftp or otherwise, and from where exactly,
>for building a public domain type Ada83 compiler for Windows NT?
>  
>Thanks in advance for any info.
>  
Well, there is as yet no public-domain-type _true_ compiler for Ada on
any platform. Ada/Ed is there, which handles full Ada83 except for some
Chapter 13 stuff that doesn't make sense for its virtual-machine execution.

Is Ada/Ed a compiler? Certainly it is. It has the usual lexical, syntactic,
semantic, and code-generation phases, and sure looks like a compiler.
It's just that the back-end delivers instructions for a virtual machine.
Ada/Ed just happens to come with a software emulator for that machine; some
would call that emulator an interpreter.

You could probably build Ada/Ed on NT; the C source code is available from
wuarchive.wustl.edu, in languages/ada/compiler/adaed. It should be pretty
straightforward if your C compiler is gcc-compatible. 

So Ada/Ed is both a compiler and not a compiler. Suppose you need real code?

As far as I know, nobody has written a virtual-code-to-real-code back-end
for Ada/Ed. It certainly would be possible, though I think it's a bit late in
the day to start with that (if only it had been done 5 years ago...).
Better to get your arms around the structure of GNAT, which will shortly
(December 93) be able to handle all of Ada9X and be freely available
via the usual GNU distribution channels.

GNAT is available now for SPARC, but that is an interim release that doesn't 
yet compile all of Ada, though it will syntax-analyze all of Ada9X and 
do partial semantic analysis as well. It is written in Ada83; ports to
other platforms will apparently be handled via the gcc cross-compilation
scheme, though NYU has not finalized the method yet. The goal is to permit
distribution and porting using only gcc facilities, without needing to
have an Ada compiler to compile your Ada compiler :-) Indeed, as NYU has
explained here, their current work uses GNAT to compile new versions
of itself, so it's a classical bootstrapping situation. You can ftp
GNAT from cs.nyu.edu, directory pub/gnat.

I'm not sure whether NYU is planning explicitly to do an NT port of GNAT,
though they are readying a release for OS/2, which is - so I've read -
resonably similar.

We should see commercial NT systems soon. Alsys and Meridian are (if I'm 
not mistaken) both getting NT compilers together; I think they have mentioned 
that on this group. I don't know about RR. 

If they aren't, they certainly oughta be! :-)

Mike Feldman
------------------------------------------------------------------------
Michael B. Feldman -  co-chair, SIGAda Education Committee
Professor, Dept. of Electrical Engineering and Computer Science
The George Washington University -  Washington, DC 20052 USA
202-994-5253 (voice) - 202-994-0227 (fax) - mfeldman@seas.gwu.edu (Internet)
"We just changed our CONFIG.SYS, then pressed CTRL-ALT-DEL. It was easy."
-- Alexandre Giglavyi, director Lyceum of Information Technologies, Moscow.
------------------------------------------------------------------------