From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <john@johnnowak.com>
X-Original-To: caml-list@yquem.inria.fr
Delivered-To: caml-list@yquem.inria.fr
Received: from mail1-relais-roc.national.inria.fr (mail1-relais-roc.national.inria.fr [192.134.164.82])
	by yquem.inria.fr (Postfix) with ESMTP id 08AA0BBAF
	for <caml-list@yquem.inria.fr>; Sun, 15 Nov 2009 14:27:56 +0100 (CET)
X-IronPort-Anti-Spam-Filtered: true
X-IronPort-Anti-Spam-Result: ApMCAOuQ/0quhHTij2dsb2JhbACcGwEBAQEJCwgctHqEPASBbQ
X-IronPort-AV: E=Sophos;i="4.44,746,1249250400"; 
   d="scan'208";a="40135125"
Received: from birch.site5.com ([174.132.116.226])
  by mail1-smtp-roc.national.inria.fr with ESMTP/TLS/DHE-RSA-AES256-SHA; 15 Nov 2009 14:27:55 +0100
Received: from pool-96-232-2-87.nycmny.east.verizon.net ([96.232.2.87] helo=[192.168.0.105])
	by birch.site5.com with esmtp (Exim 4.69)
	(envelope-from <john@johnnowak.com>)
	id 1N9f8z-0002Lb-Ff
	for caml-list@yquem.inria.fr; Sun, 15 Nov 2009 07:27:53 -0600
Message-Id: <EB0C6A62-9DD3-48E6-BAE8-AB68A78699A5@johnnowak.com>
From: John Nowak <john@johnnowak.com>
To: caml-list@yquem.inria.fr
Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes
Content-Transfer-Encoding: 7bit
Mime-Version: 1.0 (Apple Message framework v936)
Subject: calling OCaml from C on non-Mac platforms?
Date: Sun, 15 Nov 2009 08:27:49 -0500
X-Mailer: Apple Mail (2.936)
X-ACL-Warn: {
X-AntiAbuse: This header was added to track abuse, please include it with any abuse report
X-AntiAbuse: Primary Hostname - birch.site5.com
X-AntiAbuse: Original Domain - yquem.inria.fr
X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12]
X-AntiAbuse: Sender Address Domain - johnnowak.com
X-Source: 
X-Source-Args: 
X-Source-Dir: 
X-Spam: no; 0.00; ocaml:01 ocaml:01 mlvalues:01 val:01 argc:01 argv:01 argv:01 endline:01 ocamlopt:01 cmx:01 ocamlopt:01 -output-obj:01 cmx:01 gcc:01 ocamlc:01 

I'm trying to call OCaml from C. Essentially, I have this for "main.c":

    #include <caml/mlvalues.h>
    #include <caml/callback.h>

    void hello() {
       static value *closure = NULL;
       if(!closure) closure = caml_named_value("hello");
       caml_callback(*closure, Val_unit);
    }

    int main(int argc, char **argv) {
       caml_main(argv);
       hello();
       return 0;
    }

And the following "hello.ml":

    let hello () = print_endline "Hello, world!"
    let () = Callback.register "hello" hello

I can then compile as follows on OS X 10.5:

    ocamlopt -c hello.ml -o hello.cmx
    ocamlopt -output-obj hello.cmx -o hello.o
    gcc -c main.c -o main.o -I"`ocamlc -where`"
    gcc -o hello hello.o main.o -L"`ocamlc -where`" -ldl -lm -lasmrun

This works fine on OS X. However, it does not seem to work on Linux/ 
AMD64 or FreeBSD/AMD64. I've tried suggestions from all over the web  
and I've tried the approach given in the manual and nothing works. In  
all non-Mac cases, I get this on the second line:

    hello.o: file not recognized: File truncated
    Error during linking

One thing I can do is do this instead of the first two lines:

    ocamlopt -c -output-obj hello.ml

However, then I get the following:

    hello.o: In function `camlHello__hello_58':
    (.text+0x8): undefined reference to  
`camlPervasives__print_endline_298'
    /usr/lib/ocaml/3.10.2/libasmrun.a(startup.o): In function  
`caml_main':
    (.text+0x25f): undefined reference to `caml_data_segments'
    /usr/lib/ocaml/3.10.2/libasmrun.a(startup.o): In function  
`caml_main':
    (.text+0x273): undefined reference to `caml_code_segments'
    ...

Does anyone have a correct set of instructions for doing this on non- 
Mac platforms? Thanks.

- John