RL02 version of UNIX6?

[Paul Koning]

> On Feb 1, 2017, at 9:30 PM, Noel Chiappa <jnc at mercury.lcs.mit.edu> wrote:
> 
>> From: Paul Koning
> 
>> Yes, GCC should do that correctly. ... Dealing with the output might be
>> a nuisance ... You may need some post-processing to cast the output
>> into the syntax that V6 "as" expects.
> 
> Actually, dealing with the _input_ is going to be a PITA (so my suggestion
> was, in retrospect, not really a plausible one). The problem is that V6 is
> written in an early dialect of C, one which I am sure would cause GCC would
> toss its cookies, if fed to it.
> 
> Some things, like "a =+ b;" would be easy to fix; likewise "int a 1;" instead
> of "int a = 1;". But the Unix kernel is shot through with places where are
> int is used as a structure pointer, etc, without benefit of a cast (casts
> weren't invented until later). And a lot of stuff like that.

Yes, that would be an interesting issue.  One answer would be to write a new front end ("Old C").  That's probably more work than can easily be justified, though.

	paul