Re: [Caml-list] problem creating .cma library

[Basile STARYNKEVITCH <basile@starynkevitch.net>]

Guillaume Yziquel wrote:
> 
> However, I had a look at
> 
>     https://yquem.inria.fr/caml/svn/ocaml/version/3.09/byterun/sys.c
> 
> and more specifically at the function
> 
>> CAMLprim value caml_sys_exit(value retcode)
>> {
>> #ifndef NATIVE_CODE
>>   caml_debugger(PROGRAM_EXIT);
>> #endif
>>   exit(Int_val(retcode));
>>   return Val_unit;
>> }
> 
> or the function
> 
>> CAMLprim value caml_sys_close(value fd)
>> {
>>   close(Int_val(fd));
>>   return Val_unit;
>> }
> 
> Why do these functions not follow the usual CAMLparam/CAMLreturn macro 
> stuff?
> 

Because they are written by the Ocaml guys (Damien knows really well the Ocaml garbage collector; he wrote it). And 
also, because these particular functions do not do any allocation of Ocaml values (either directly or indirectly).

My advice for people coding C code for ocaml is the following:

1. *always* use the CAMLparam/CAMLreturn/... macros.

2. if you dare not using them for some very few functions (because they don't allocate, ...) add a big fat comment with 
a warning inside.

Regards


-- 
Basile STARYNKEVITCH         http://starynkevitch.net/Basile/
email: basile<at>starynkevitch<dot>net mobile: +33 6 8501 2359
8, rue de la Faiencerie, 92340 Bourg La Reine, France
*** opinions {are only mines, sont seulement les miennes} ***