[Oberon] OP2 compiler assessment

[Chris Burrows]

> -----Original Message-----
> From: skulski at pas.rochester.edu [mailto:skulski at pas.rochester.edu]
> Sent: Sunday, 2 November 2014 4:10 AM
> To: Richard Hable
> Cc: oberon at lists.inf.ethz.ch
> Subject: [Oberon] OP2 compiler assessment
> 
>   thank you for describing the OP2. I have heard many times it was
> not an easy piece to digest. OK, down the list of things "to do" we
> can put the
> OP2 compiler cleanup and a book titled "Compiler Construction In Real
> World".
> 

The 'right time' to do that for OP2 came and went many years ago. If you
want a 'Real World' book that already exists you should read "Compiling for
the .NET Common Language Runtime" by John Gough the author of the Gardens
Point series of Modula-2, Oberon-2 and Component Pascal compilers. Code
snippets in the book are written in Component Pascal. 

GPCP is another Oberon-2+ compiler which uses intermediate language to
separate the front-end from the back-end but it is not a descendant of the
OP-2 compiler. The full source code for the GP Component Pascal compilers
(both CLI and JVM versions) can be downloaded from:

http://gpcp.codeplex.com/

A previous message in this mailing list mentioned the possibility of a
version of GPCP which targets LLVM (the favour of the month in the world of
intermediate languages).

https://lists.inf.ethz.ch/pipermail/oberon/2012/006605.html

For those who haven't hear of LLVM a good introduction is here:

http://www.aosabook.org/en/llvm.html

 
> Is MIPS open-source and royalty free? Wikipedia says "Companies can
> also obtain an MIPS architectural licence for designing their own CPU
> cores using the MIPS instruction set". See
> http://en.wikipedia.org/wiki/MIPS_Technologies
> 

A MIPS core that runs on the same Digilent Spartan 3 Starter board used for
RISC5 Project Oberon is available: 

http://opencores.org/project,plasma

It is stated to be a "clean room" implementation. In the "Avoiding
limitations" section it does refer to operations that were the subject of a
1986 patent.

Regards,
Chris

Chris Burrows
CFB Software
http://www.cfbsoftware.com/gpcp