[Info-vax] ADA and VMS (was Safer programming languages)

[Bill Gunshannon]

On 11/15/21 7:35 PM, Arne Vajhøj wrote:
> On 11/15/2021 6:28 PM, Bill Gunshannon wrote:
>> On 11/15/21 4:18 PM, Robert A. Brooks wrote:
>>> On 11/15/2021 4:01 PM, Bill Gunshannon wrote:
>>>> This talk of Ada, VMS and Systems programming has raised a new
>>>> question in my mind.
>>>>
>>>> Given that Ada got it's start on VMS (one of the first validated
>>>> Ada Compilers was on VMS) has any attempt ever been made to write
>>>> any part of VMS using Ada?  Device Driver? Anything?
>>>
>>> ACME_SERVER and SECURITY_SERVER are written in ADA.
>>>
>>> Both are being rewritten in C.
>>
>> Were there ever any internal benchmarks run against them so that
>> a comparison of performance when the C conversion is done could
>> be looked at?
> 
> Depending on how many checks were disabled in the Ada version, then
> the C version may be a little or a lot faster,
> 
> But I cannot imagine it having any significance on modern hardware.
> 
> They did not rewrite in C to save CPU cycles but because they did
> not have an Ada compiler for the new platform.
> 

I realize all that.  I would just like to see some comparisons.
I don't know that any were actually done.  It all goes back to
a comment I got from someone from the Ada Users Group about 30
years ago.  I mentioned an interest in a version of Unix rewritten
in Ada and was quickly informed that while it could be done it
would result in a useless operating system because the Ada version
would be very inefficient.  Needless to say, I never tried it.
Might be fun to dig up some benchmarks and try it, but I always
prefer real world examples to contrived benchmarks.

bill