Re: [Caml-list] segfault in simple program with 4.02 native

[Martin Jambon <martin.jambon@ens-lyon.org>]

On Sun 07 Sep 2014 11:47:43 AM PDT, Alain Frisch wrote:
> On 9/6/2014 7:51 AM, Martin Jambon wrote:
>> Thanks for the explanation, Jeremy. I guess atdgen will have to use
>> "option refs" after all unless someone has a better idea.
>
> I might be missing some context, but the current code seems to playing
> two different tricks with the type system:  using (Obj.magic 0.) as a
> dummy initial default value (to avoid references) and mutating
> normally immutable fields with Obj.set_field.  Is that right?

Yes, exactly.

>  You
> might be able to keep the first trick, but storing the values in local
> references instead of field of the the target record (if those
> references don't espace from the function, they will be represented as
> local mutable variables, whose mutation might actually be more
> efficient than those of the record fields),  building the target
> record at the end by reading from those references.

Christophe Troestler also suggested this solution in a private reply. I 
was afraid of the cost of the refs, so it's great to know that they're 
optimized away.

I want to thank everyone for their suggestions. It's very helpful.

Martin