Js_of_ocaml can now compile cmo and cma

[hhugo]

Example:
Compile the stdlib and an ml file (test_cmo.ml)

js_of_ocaml `ocamlc -where`/stdlib.cma -o stdlib.js
ocamlc -c test_cmo.ml
js_of_ocaml test_cmo.cmo

Run with

    <script type="text/javascript">
      var joo_global_object=this
    </script>
    <script type="text/javascript" src="runtime/runtime.js"></script>
    <script type="text/javascript" src="runtime/predefined_exceptions.js"></script>
    <script type="text/javascript" src="stdlib.js"></script>
    <script type="text/javascript" src="test_cmo.js"></script>

[Drup]

Wow, Great work! I think that is going to be very useful!

cc @andrewray Pretty sure you can simplify iokerneljs with that.

[andrewray]

We can currently dynamically load libraries but that tends to lead to stack overflows. Will need to test if this improves matters. If so, then this is very interesting!

@avsm Its possible we could set up a build service for ocaml libraries with this.

[avsm]

@andrewray I'll happily set up the bulk builds to expose this via opam.ocaml.org as a HTTP service! Just ping me whenever there's a released version of js_of_ocaml and I'll make sure that the right build artefacts are made available from the bulk engine. /cc @dsheets @samoht

[hhugo]

@andrewray do you know what's causing the stack overflows you're talking about ?

[bobzhang]

This looks cool, but I got an error when trying this feature

play_js> js_of_ocaml t.cmo                                                                                                                                                    
js_of_ocaml: Error: Not an ocaml bytecode file                                                                                                                                 
js_of_ocaml: Error: Invalid magic number "d\027\n\139\214\204\220@@@@@" 

[bobzhang]

I am using the master branch, so it should include this thing

[hhugo]

a cmo should start with Caml1999O010.
what's the output of head -c 12 t.cmo

[ejgallego]

@hhugo , we are also getting stack overflows with dynamic compilation.

I'm trying to debug them, meanwhile you can see an example using firefox and loading ssreflect as instructed in (https://x80.org/rhino-coq/).

Chrome will also SO if loading ssr in the standard way:

Require Import Srreflect.ssreflect.

Thanks,
E.

[hhugo]

there is now an example of separate compilation 9b59580