[Info-vax] VSI C/C++ compiler for OpenVMS expired yesterday!

[Chris Townley]

On 04/09/2023 22:23, John Reagan wrote:
> On Monday, September 4, 2023 at 4:12:19 PM UTC-4, Single Stage to Orbit wrote:
>> On Mon, 2023-09-04 at 12:57 -0700, John Reagan wrote:
>>> On Monday, September 4, 2023 at 8:18:49 AM UTC-4, Simon Clubley
>>> wrote:
>>>> On 2023-09-02, John Reagan <xyzz... at gmail.com> wrote:
>>>>> Again, my apologies for the ancient timebomb (long story)
>>>>>
>>>> It happens :-) however much it would be nice it didn't... :-)
>>>>
>>>> Has anyone checked to make sure there are no timebombs waiting
>>>> to go off in the other products ?
>>>
>>> C++ was the first native compiler prior to all of the LMF code (and
>>> PAKs) being in place.
>>> All of the other compilers and LPs rely on the termination date
>>> feature of a PAK.
>> That makes complete sense, can't bootstrap without a working toolchain.
>> What did you use as the host to build the toolchains and all the x86_64
>> bits for VMS jut out of interest? Is OpenVMS for x86 now self hosting
>> and can it build itself?
>> -- 
>> Tactical Nuclear Kittens
> 
> For the Itanium-hosted cross-compilers, I grabbed LLVM 3.4.2 (the last LLVM
> release that claims to be buildable with a C++03 compiler) and compiled it
> on OpenVMS Itanium.  Our GEM-to-LLVM converter is also written in C++03.
> 
> We hooked these pieces to the Itanium frontends for C and BLISS and they just
> think they are talking to GEM.  The G2L/LLVM 3.4.2, we then had working cross-compilers
> to build the OS and for bootstrap some of the compiler pieces (our frontends are written
> either in C and/or BLISS)   The Macro compilers is similar but used a smaller portion of
> LLVM and needed other work (think of it as the equivalent of G2L).  And the Macro-32
> parser is written in Macro-32.
> 
> For native compilers, we initially used those cross-compilers to build x86 versions of the C
> and BLISS frontend.  For C++, we had no cross-compiler (clang 3.4.2 wouldn't go thru the
> Itanium C++ compiler no matter how hard I pounded on it it).
> 
> For the building LLVM (and G2L) that were OpenVMS aware, we first took LLVM/clang 10.0.1
> (the current version at the time) and built them on Linux.  We then added some OpenVMS
> features and again built those compilers on Linux (call them clang 10.0.1v).  Now use THAT
> compiler (Linux-hosted, OpenVMS-target) to build clang 10.0.1v again with more features.
> Move those objects over to an OpenVMS box.  Do the same thing with libcxx.  Link them all
> together.  libcxxabi needs work to layer the code which wants libunwind onto a system with
> the LIB$CALLING standard routines.  Same concepts, different names (and we have some
> of a GPL-free libunwind inside of the LIB$ routines).
> 
> We are now using those 1st generation native compilers to build the 2nd generation
> native compilers except for C++.  We're still doing the Linux thing for now as the LLVM/clang
> build needs things like CMake (which of course is written in C++ and needs to be bootstrapped
> with a C++ compiler).  Those 2nd generation compiler builds are done on OpenVMS x86 V9.2-1
> systems on a hypervisor.  Testing is also done on virtual machines.
> 
> The native compilers have most of the optimization but those 1st generation compilers themselves
> are unoptimized (they are built with cross-compilers).  The 2nd generation native compilers are themselves
> built with optimization and generate optimized code.
> 
> As for the OS itself, the build system is a little more complex (and baroque) and is still being worked on.

Thanks for that - it is nice to see some of the hoops you have had to 
jump through!

-- 
Chris