Re: ISO: The Eiffel OO programming language and IDE, on VMS

On 3/26/2025 8:14 AM, Dan Cross wrote:

In article <vs0qdf$1mlt9$1@dont-email.me>,
Arne Vajhøj  <arne@vajhoej.dk> wrote:

On 3/26/2025 1:09 AM, David Meyer wrote:

Is there anything in the VSI licensing that would prevent a community of
VMS and Rust (for example) fans from developing a VMS port of a Rust
compiler and releasing the compiler as open source?

>
No.
>
VMS users can write or port all the compilers they want to. And
they have done so in the past: old versions of GCC C and C++ ran on
VMS VAX and VMS Alpha, old versions of Gnat Ada ran on VMS Alpha
and VMS Itanium.
>
The reason it is not happening is not license restrictions, but
lack of interest (willing to do work type of interest - not
it would be nice if somebody else did the work interest) in
the VMS community.
>
The specific discussion was about the LLVM compiler backend,
that VSI use for their compilers. If VSI made that available
(it is open source) then it would be easier for people to
write or port new compilers using LLVM as backend.

 The official Rust compiler is an interesting case in point, as
it's already built on LLVM.  Getting it running on VMS probably
wouldn't be that hard; getting it to output code targetting VMS
is probably harder, but certainly doable.

Oversimplified I believe work would be:
"frontend" - should not be VMS specific, but it is written
in Rust so a bootstrapping process is needed - compiler bootstrapping
is a known concept, but still some work
"backend" - LLVM, if VSI release their VMS LLVM changes some integration
work, if not a huge porting work
"library" - effort will depend on how much is directly calling the OS
(meaning LIB$ or SYS$ calls on VMS) and how much it is utilizing the
C RTL - I don't know that so it can be little or much work
"VMS stuff" - installation script, VMS debugger support,
the equivalent to the C descrip.h, starlet.h and lib$routines.h etc. -
also some work (but when that work start then the goal post
is in sight!)
Certainly doable. It is being done all the time. Similar work has
been done on VMS in the past.
But still let us call it "non trivial".
Arne