Re: Octave Compiler

[JD Cole]

Jens,
   I've looked (and done) a little bit of work in this same direction. 
Are you talking about writing an actual compiler, or an Octave to C++ 
code generator? In the case of the latter, you might consider 
integrating the code generator into the main Octave source. That said, 
when developing a new, semi-large addition to this source tree, 
recompilation is a bit cumbersome, so, what I have taken to doing is 
developing via ".oct" files. This should give you access to all of the 
Octave internals,  while allowing you to only recompile your source 
code. (Take note that there are a few gotcha's in developing this way, I 
recall having some trouble when I wanted to check if a symbol was a 
function or not.)
   Since you're probably going to start with parsing, you should 
familiarize yourself with the parse-tree structures, base class is 
"tree" and tree walking stuff, base class "tree_walker", found in "pt.h" 
and "pt-walk.h", respectively. The tree_walker class allows you to visit 
each node in the parse tree in an ordered fashion. I will attach the bit 
of code which I started. The code is basically what you find in 
pt-pr-code.cc, with a few additions so I can see what goes where. You 
should be able to just do a 'make' to produce 'compile.oct" and then, 
using the example 'mysum.m', start up octave and 'compile('mysum')', it 
should produce just a simple template and then some debug information. 
(The code worked as of Octave version 2.1.45, but I haven't tried it 
with new versions yet.) If you're going to compile it, you'll also want 
to remove any references to "parallel" in pt-emit-cplusplus, these are 
additions I've made to try to give Octave some parallel support.
   I'd be happy to work with you on this project, if you're so 
inclined, or, at the very least, pass on the other tidbits I'd been 
thinking about with respect to octave to c++ converter. That will just 
take a little revival.
   There are two quite interesting alternatives to converting to C++ 
that I had been kicking around. One was creating a Just-In-Time compiler 
for Octave. The other is actually writing a front end for gcc to compile 
directly to binary from octave code. While the former could potentially 
provide a good performance increase for the standard Octave user, the 
latter may not be relevant, it just sounds like a cool project to me. 
There is plenty of literature on the JIT compiler in regards to Matlab.

Hope this helps,
JD
Jens Ruecknagel wrote:

> To whom in concerns,
>
> As a student research project I want to develop an Octave to C++ 
> compiler.
>
> About me:
> My name is Jens Ruecknagel. I am a student at Technical University of 
> Ilmenau, Germany in the course computer science in my 4th and final 
> year. After finishing my degree I am going to be am diploma computer 
> scientist (comparable to a master degree). I already have some 
> experience in developing programming languages.
>
> My project:
> I am trying to adapt the Lex/Yacc grammar of Octave to fit the needs 
> of an Octave to C++ compiler. And I am developing a backend to 
> generate C++ code.
>
> I am just starting to work on this project, therefore I am still 
> “reading” the Octave code to find out which parts of the Octave 
> project I can use.
>
> I think, I can use the Lex/Yacc parser which (I suppose) constructs an 
> abstract syntax tree which then will be feed to the my compilers backend.
> I’m still thinking about which numerical libs the generated code shall 
> depend on – I’ll probably use liboctave first and maybe replace it later.
>
>
> So I hope you answer some questions about Octave:
>
> Do you have any additional documentation on the Octave source code?
> On which Octave version should the compiler be based on? I was 
> thinking I use 2.1.50.
> Can you give me some hints about my task?
>
>
>
> May I bother you again, if I run into problems? (I am sure there will 
> be some problems :-))
>
>
> Tanks a lot,
>
> Jens Ruecknagel

oct-compiler.tar.gz
Description: GNU Zip compressed data