[m-users.] Building Mercury on RiscOS, anybody tried ?

[Sean Charles (emacstheviking)]

Um, yeah. Thanks.
Moving on….
:D

> On 15 Jun 2021, at 11:27, Julien Fischer <jfischer at opturion.com> wrote:
> 
> 
> Hi Sean,
> 
> On Tue, 15 Jun 2021, Sean Charles (emacstheviking) wrote:
> 
>> I have RiscOS on a Pi4 with 4GB of RAM… and it occurred to me that,
>> with the rigour and beauty of Mercury, it would make a wonderful
>> development tool, the FFI layer would be the first goal I guess to
>> talk to the native UI libraries etc.
>> 
>> I absolutely cannot believe how fast RiscOS runs even compared to
>> 64-bit Ubuntu on the Pi, it feels like the good old days when a 1MHz
>> 6502 was state of the art.
> 
> I'm not aware of anyone porting Mercury to RISC OS.
> 
>> I wondered what the technical hurdles might be… initially setting up a
>> compiler environment for one thing and then, addressing the ‘unusual’
>> way in which the RiscOS compiler addresses C files through a tree
>> rather than a file extension, as I understand it so far.
> 
> A few pointers, when porting Mercury to a new platform you need to
> consider:
> 
> * Does the Boehm GC work on the new platform?
> 
> * Is thre a usable build toolchain: C compiler, POSIX style shell,
>  GNU make, flex and bison available?
> 
> * Threads in Mecury currently assume the presence the POSIX threads
>  API.
> 
> Things may minimally work at that point, but most new ports also
> require at least some of the following:
> 
> * Changes to runtime/mercury_conf_param.h to add macros related
>  to the new platform.
> 
> * Changes to the configure script, e.g. to tell the Mercury compiler
>  what flags to pass to the linker, how to build share objects on the
>  new platform.
> 
>  Some tests in the configure script may need to be disabled or have
>  their results forced.
> 
> * To support the asm_fast and reg grades, various changes may need
>  to be made the runtime such as defining global registers (in
>  runtime/machdeps) and (maybe) runtime/mercury_goto.h.  Also,
>  possibly to runtime/mercury_atomic_ops.h if the .par grades
>  are to be supported.
> 
> * Various places in scripts/mgnuc.in and scripts/ml.in may need
>  additions for the new platform.  (Those scripts are what mmake
>  uses to "drive" the C compiler and linker respectively.)
> 
>  The Mercury compiler itself may require similar changes in
>  compiler/compile_target_code.m so that mmc --make knows how
>  drive the C compiler toolchain.
> 
> * Platform dependent foreign_procs in the standard library may
>  need to be extended or have alternatives for the new platform
>  added.  The io, dir and time modules are likely candidates for
>  requiring such changes.
> 
>> It MIGHT be easier to cross compile for ARM7 on my Mac though, if
>> that’s possible with Mercury ?!
> 
> ARM7 should be supported, although it's been a while since anyone
> has reported using it with Mercury.  (It was being used with Linux,
> last I heard anything about it.)
> 
> Recent ROTDs have a script for configuring Mercury as a cross compiler,
> in tools/configure_cross.  It currently supports cross compiling to
> i686-*-mingw32, x86_64-*-mingw32 and aarch64-linux-gnu (see README.cross
> for details), but it should be fairly straightforward to extend to other
> platforms.
> 
> Julien.