Re: Clair Grant on VMS code base

Simon Clubley <clubley@remove_me.eisner.decus.org-Earth.UFP> writes:

On 2025-04-03, Arne Vajh�j <arne@vajhoej.dk> wrote:

On 4/3/2025 2:15 PM, Simon Clubley wrote:

On 2025-04-01, Arne Vajh�j <arne@vajhoej.dk> wrote:

He looks at size 6.2 -> 7.2 -> 8.2 -> 9.2 and .mar vs .c 6.2 -> 9.2.

https://vmssoftware.com/resources/blog/2025-03-31-how-big-is-vms/

How the hell does DCL have 30,000+ lines of code ? :-)
(Even allowing for the fact most of it is in Macro-32)

Just for fun I downloaded bash and counted. 117 KLOC.

Wow. I had no idea it was now that big. OTOH, bash has got a _lot_ more
functionality in it than DCL does.

Also, regarding those BLISS/Macro-32 figures across the various modules
in general, I wonder how much smaller the code would have been if it had
been written in C ?

C is a relative high LOC/FP language.

Most LOC/FP tables have C in the 100-125 range and macro-assembler
in the 200-250 range.

If we adjust for VAX instructions being more powerful/complex
than average ISA, add a random number and subtract wind speed I
will estimate the Macro-32 / C ratio to be around 1.5-1.75.

If you buy that then the DCL 33 KLOC would be 19-22 KLOC in C
to be compared with bash 117 KLOC.

The problem with that analysis is what DCL does.

It basically parses, validates, and executes commands it has been given.
That is something which can be implemented a lot more easily and concisely
in a HLL with abstracted data structure capabilities (which includes
even C) than an assembly language with no such capabilities.

That also depends on the operating system environment.

TOPS-20, on later PDP-10 systems including clones, has a built in system call
COMND% which is a fully capable command parser which includes context sensitive
help, switch parsing, etc.

High-level languages on TOPS-20 have COMND% calls in their run time systems.

--
Rich Alderson   news@alderson.users.panix.com
      Audendum est, et veritas investiganda; quam etiamsi non assequamur,
  omnino tamen proprius, quam nunc sumus, ad eam perveniemus.
--Galen