Re: A question for my personal knowledge.

[<bglbv@my-dejanews.com>]

Charlie McCutcheon <"cmccutcheon@NOSPAMbegin"@enet.dec.com> writes:

> Parts of OpenVMS, most recent versions, I think at least 6.2 on.

At that level of certainty I might as well reiterate my own vague
recollection. (Unfortunately, when I tried to track down the specifics
recently I found that DejaNews had not preserved the postings where
the most detailed and reliable information appeared, and the OpenVMS
FAQ is short on specifics.)

Anyway, my recollection is that use of Ada in VMS development started
with version 4.0 of the operating system. This would place the
beginnings of such activity in the 1983-1984 time frame, more or less
when DEC's first Ada compiler for the VAX came out. It is good
practice to test new software products by exercising them in-house,
so this makes at least some sense.

I have a hunch that the SMG$ screen management routines may have been
written in Ada, but this is just a guess on my part (I won't say how
educated).

I suppose someone with access to a VMS system could go through system
executables and shared libraries and watch for the Ada compiler's
idiosyncracies in code generation. (Things like working out the size
of everything in bits rather than bytes, for example. Certainly if I
wanted to search for GNAT-generated code on an x86 I would look for
sections with a high density of arithmetic shifts left by 5. Similar
heuristics should work with other compilers and on other platforms.)

> Not major parts mind you.  Some sub-sections where the programmers involved
> wanted to use Ada.

My understanding is that the use of Ada resulted in measurable
productivity gains. Pity I don't have the original reference anymore.