NOCC: a new occam-pi compiler

Welcome to the "new occam-pi compiler" webpage, an attempt to collate information/resources/documentation on the new occam-pi compiler.

[ status | introduction | intentions | download ]

• latest is nocc-0.1.4

Current Status

The bulk of the compiler documentation, including status, has been moved into the research-group Wiki, here: https://www.cs.kent.ac.uk/research/groups/sys/wiki/NOCC/

Introduction

This compiler is a modern re-implementation of the existing occam-pi compiler (originally from the Inmos occam toolset), that attempts to by highly dynamic and extensible, as well as being reasonably efficient. Like the original, this compiler is programmed in C (but supports several internal "mini-languages" to ease compiler construction).

I've probably had a bit too much fun hacking in places.. ;-). Some parts of the compiler, particularly its aggressive use of function-pointers, hint towards C++. But generally, C is more efficient and I prefer the more direct representation of what's going on in a program, not hidden behaviours as introduced by inheritance/etc. in OO. Also, this compiler is not garbage-collected, and some unpleasant surprises come about as a result of that in C++. Thus, I've used C. Live with it. :-)

On a side note, gdb and valgrind make excellent debugging tools.

Intentions

Here are some things that I've been keeping in mind whilst writing this compiler:

• Compiler maintanence shouldn't be a complete nightmare, as is the case with the current compiler
• Should be easy, e.g., to change the language grammar slightly
• Should be reasonably easy to support other language syntaxes (e.g. a C-style syntax)
• Should be reasonably easy to extend the language, e.g. for things like INITIAL parameters, infrastructure for KRoC.net
• Should be possible to do some of this at run-time, e.g. loading a 3rd-party add-on that provides some new type and any specific language bindings for it
• This should ultimately be an industrial-strength compiler, yet, it'd be nice to put experimentation in the realm of ordinary programmers (e.g. students)

Download and Installation

Here it is..! still very much under construction. The latest/current versions are available from the subversion repository. If you would like write access to the repository, sign up for an account on projects.cs.kent.ac.uk and let me know your username (and why you want write access, of course!).

• 17/11/2007: nocc-0.1.4.tar.gz
• 31/12/2005: nocc-0.1.3.tar.gz
• 31/12/2005: nocc-0.1.3.tar.gz
• 29/05/2005: nocc-0.1.2.tar.gz
• 09/05/2005: nocc-0.1.1.tar.gz

To use the compiler in practice:

• get the latest KRoC release (1.5.0-pre3 or greater), or find your existing source tree
• reconfigure the KRoC package to use nocc, if using an existing source-tree, do:

  
      bash$ ./build --reconf -A --force-configure configure-kroc make-kroc install-kroc
  			

  else if using a fresh source-tree, do:

  
      bash$ ./build -A
  			

  in the configuration, select "I" (i) to set the NOCC compiler path:

  
       I. path to NOCC install: 
  
      1-7 to change path, A-E, F-XK to toggle/set feature, Ctrl-C to abort,
          return to confirm and install: i
      path to NOCC install: /path/to/nocc/tree
  			

  kroc expects to find the compiler executable and the "nocc.specs.xml" file in the given directory.
• then build/install the KRoC system or re-configured 'kroc' (by pressing return at the configuration menu generally).
• run kroc as you would normally, but with the additional "--nocc" flag, e.g.:

  
      bash$ kroc -v --nocc myprog.occ
  			

  the kroc flag --nocc-opts=... can be used to pass extra options to nocc.