Re: [Chicken-hackers] how to -block?

[Jörg F . Wittenberger]

On Apr 5 2013, Felix wrote:

> From: Jörg F. Wittenberger <address@hidden>
> Subject: [Chicken-hackers] how to -block?
> Date: 31 Mar 2013 20:51:19 +0200
>
> > I'm trying to figure out howto use -block optimization.
> >
> > Whenever I use it with any module no matter how simple it is,
> > the resulting binary will segfault immediately.
> >
> > Which restrictions should I watch?
>
> If you get a segfault, do you compile/run code in unsafe mode?

Yes.

Accidentally.

The uses/import consusion as it turned out. … Took me >2 full days
to work that out.

Maybe we should recommend in the manual to NOT ever have "uses"
and "import" in the same file.  By doing so, I managed to make
the compiler miss unbound variables.  For whatever reason those
where eventually bound when accessed - at least most of the time.

By cutting out all "uses" from all modules and accumulating them into
a single "link-file" (having no code except for a single import
of the toplevel "main" procedure and call it I've been able to
track several unboudn variables down.  (Those came from code-
rearrangements done under the safe-feeling that chicken points
unbound variables out anyway.  You should never trust…)

Now I shall go back and retry with the -block.


Thanks

/Jörg

> Block-optimization should normally not result in crashes, but will
> produce runtime-errors when variables are referenced that are not
> bound. In block mode, defined toplevel variables will not be exposed
> and not be visible to code outside of the file compiled in that mode.
> This is really the only difference to compilation in normal mode.
>
>
> cheers,
> felix