Re: [Chicken-users] Segmentation violation with chicken 5.1.0

[Sven Hartrumpf]

Peter Bex wrote, 2019-06-23 14:51:
> On Sun, Jun 23, 2019 at 02:33:10PM +0200, Peter Bex wrote:
>> [panic] Low-level type assertion 
>> C_blockp((C_word)C_VAL1(C__PREV_TMPST.n1))=#t failed at chickenprob3.c:93488 
>> - execution terminated
>
> Here's a minimal reproducible testcase:
>
> (define (test-it)
>   (let loop ((done #f))
>     (if done
>         '()
>         (cons  (or (read) 0.0) (loop #t)))))
>
> (print (test-it))
>
> This generates exactly the same construct:
> f0=C_flonum_magnitude((C_truep(t1)?t1:lf[1]));

Very good!

> If you type in a fixnum integer, this will break too.
>
> I've filed a bug to track this: https://bugs.call-cc.org/ticket/1624
>
>
> A quick workaround for your program might be to return the 0.0 from a
> foreign lambda, like so:
>
> (define return-zero
>   (foreign-lambda* float () "C_return(0.0);"))
>
> (define (test-it)
>   (let loop ((done #f))
>     (if done
>         '()
>         (cons  (or (read) (return-zero)) (loop #t)))))
>
> (print (test-it))
>
> It's stupid, but it works.

Thanks for the suggestion. I will use another Scheme compiler
until this is fixed because there are more cases like this in
my (non-reduced) source, if I recall correctly :-)

Ciao
Sven