C stubs with many args.

C stubs with many args.

[Guillaume Yziquel]

Hi.

I've been recently reworking Maxence Guesdon's OCaml-R binding in order 
to provide a tighter integration with, and I'm currently trying to 
reverse-engineer the way closures are handled in R. So I've written up 
this small C stub code for a function with 6 parameters:

> void Rf_begincontext (RCNTXT * cptr, int flags, SEXP syscall, SEXP env, SEXP sysp, SEXP promargs, SEXP callfun);
> CAMLprim value r_reveng_begin_context_native (value flags, value syscall, value env, value sysp, value promargs, value callfun) {
>   CAMLparam5(flags, syscall, env, sysp, promargs);
>   CAMLxparam1(callfun);
>   CAMLlocal1(result);
>   result = caml_alloc(1, Abstract_tag);
>   Rf_begincontext ( (context) Field(result, 0), Int_val(flags), Sexp_val(syscall), Sexp_val(env),
>                     Sexp_val(sysp), Sexp_val(promargs), Sexp_val(callfun));
>   CAMLreturn(result);
> }
> CAMLprim value r_reveng_begin_context_bytecode (value * argv, int argn) {
>   
> } 

I've been trying to follow section 18.1.2 of:

	http://caml.inria.fr/pub/docs/manual-ocaml/manual032.html

Unfortunately, I'm a bit confused as to what should the CAMLparam and 
such be for the bytecode stub.

Could someone provide me with an example somewhere?

All the best,

-- 
      Guillaume Yziquel
http://yziquel.homelinux.org/

Re: [Caml-list] C stubs with many args.

[Guillaume Yziquel]

Guillaume Yziquel a écrit :
> Hi.
> 
> I've been recently reworking Maxence Guesdon's OCaml-R binding in order 
> to provide a tighter integration with, and I'm currently trying to 
> reverse-engineer the way closures are handled in R. So I've written up 
> this small C stub code for a function with 6 parameters:

OK. Figured it out. Stupid me:

> void Rf_begincontext (RCNTXT * cptr, int flags, SEXP syscall, SEXP env, SEXP sysp, SEXP promargs, SEXP callfun);
> CAMLprim value r_reveng_begin_context_native (value flags, value syscall, value env, value sysp, value promargs, value callfun) {
>   CAMLparam5(flags, syscall, env, sysp, promargs);
>   CAMLxparam1(callfun);
>   CAMLlocal1(result);
>   result = caml_alloc(1, Abstract_tag);
>   Rf_begincontext ( (context) Field(result, 0), Int_val(flags), Sexp_val(syscall), Sexp_val(env),
>                     Sexp_val(sysp), Sexp_val(promargs), Sexp_val(callfun));
>   CAMLreturn(result);
> }
> CAMLprim value r_reveng_begin_context_bytecode (value * argv, int argn) {
>   return r_reveng_begin_context_native(argv[0], argv[1], argv[2], argv[3], argv[4], argv[5]);
> }

All the best,

-- 
      Guillaume Yziquel
http://yziquel.homelinux.org/

Re: [Caml-list] C stubs with many args.

[Richard Jones]

On Sun, Nov 29, 2009 at 04:31:11PM +0100, Guillaume Yziquel wrote:
> I've been trying to follow section 18.1.2 of:
> 
> 	http://caml.inria.fr/pub/docs/manual-ocaml/manual032.html
> 
> Unfortunately, I'm a bit confused as to what should the CAMLparam and 
> such be for the bytecode stub.
> 
> Could someone provide me with an example somewhere?

In case you still have problems, you could look at the code we
autogenerate in libguestfs, eg: ocaml/guestfs_c_actions.c.  We
generate bindings for functions that have various numbers of arguments
(up to 9).

Rich.

-- 
Richard Jones
Red Hat