[TUHS] Software written in B

[Sebastien F4GRX]

Hello,


my own compiler choked on if.b and mail.b because of this invalid 
expression in nxtarg:

if(ap>ac) return(0*ap++);


I believe it should instead read:

if(ap>ac) return 0;


What do you think about this?


PS: The original code gives this AST which shows how my compiler 
interprets this source :

function name nxtarg
.  env: ref to function nxtarg
.  env: ref to function main
.  compound stmt
.  .  env: extern ap
.  .  env: extern ac
.  .  env: extern argv
.  .  env: ref to function nxtarg
.  .  env: ref to function main
.  .  if test
.  .  .  operation: GT
.  .  .  .  extern declaration ap
.  .  .  .  extern declaration ac
.  .  then stmt
.  .  .  return stmt
.  .  .  .  operation: MUL
.  .  .  .  .  value: 0
.  .  .  .  .  operation: POSTINC
.  .  .  .  .  .  extern declaration ap
.  .  return stmt
.  .  .  [LVALUE] operation: INDEX
.  .  .  .  extern declaration argv
.  .  .  .  operation: POSTINC
.  .  .  .  .  extern declaration ap

Sebastien


Le 17/06/2023 à 10:19, Angelo Papenhoff a écrit :
> Update: I'm now done with the first pass of this.
> I reversed all the programs and successfully ran them through my
> compiler (i haven't assembled or linked anything though).
> http://squoze.net/B/programs/
>
> To check for correctness, the files should of course be compiled,
> assembled and linked again. Unfortunately my compiler currently
> does not generate quite the same code as the original one. I will
> have to work on this.
> Most importantly & and | are only bitwise operators in the version
> of B that compiled these programs, but some other differences (like
> the fixup chain and the way strings are stored) exist too.
>
> It would be nice to have a fully working B system on v1/v2 UNIX again,
> with everything built from source, we can even reconstruct different
> versions of the runtime (and perhaps standard library). So far the
> PDP-11 version of my B system has only run on v6 and 2.11BSD.
>
> best,
> aap
>
> On 14/06/23, Angelo Papenhoff wrote:
>> I will hopefully continue with this in the next time (if, goto, mail and
>> glob are left).