Re: [Caml-list] When to (not) use -no-naked-pointers?

[Fabrice Le Fessant <Fabrice.Le_fessant@inria.fr>]

Hi,

  Naked pointers only appear in C bindings when pointers to C
structures are passed directly as OCaml values. Non-naked pointers are
the ones which are hidden within either a custom block or a block with
the "abstract" tag (Tag_abstract). It is normally easy to modify a
binding to switch from naked-pointers to non-naked pointers (it could
even be a configure script option of the binding). The only case where
there is a (big) problem is when the binding is allocating OCaml
values outside of the heap: it is the case for the "ancient" library,
for example, that copies OCaml values outside of the heap to avoid
garbage collections; it is also the case for some bindings that create
OCaml string headers in front of C buffers, to be able to manipulate
them directly in OCaml (I did that once to share OCaml strings between
processes, using shared memory).

--Fabrice
INRIA &OCamlPro


On Mon, May 25, 2015 at 8:25 AM, Jez <jezreel@gmail.com> wrote:
> Hi,
>
> I noticed that 4.02 now has the no-naked-pointers option. I'd like to better
> understand when I shouldn't use it -- i.e. what kinds of operations create
> naked pointers? I suppose that these pointers can only be generated by C
> code; an example of when their use may arise would be nice :)
>
> Jez



-- 
Fabrice LE FESSANT
Chercheur en Informatique
INRIA Paris Rocquencourt -- OCamlPro
Programming Languages and Distributed Systems