Re: oasis patch that adds an .nobj.o target

[Anil Madhavapeddy <anil@xxxxxxxxxx>]

I've put in a further changeset into OASIS to add a new "Target" field
to the Executable section.  Just set this to "xen" and it will build that
target instead.  You still need CompiledObject:native as that will put
the correct _tags entries in for the .nobj.o target (which is the final
link phase). See:

https://github.com/avsm/ocaml-xenstore/commit/0c1b80ddba612487b7f97ff4c2444a10e451196d

...for what I mean in ocaml-xenstore.

So given that we should be able to compile the libraries with *either*
--enable-unix or --enable-xen, and the appropriate binaries will be built
with the current toolchain and OASIS.  Good enough for a first release!

The OPAM packaging can signal the current environment that is set via
environment variables --- currently MIRAGE_OS and MIRAGE_XEN.  I guess
the final step is a ./configure script that detects these and translates
them into the correct 'ocaml setup.ml --enable-foo' flags.  Will do that
when I'm off this train and in the office...

-anil

On 29 Aug 2012, at 02:46, David Scott <scott.dj@xxxxxxxxx> wrote:

> Hi,
> 
> Thanks for that -- "ocamlbuild xen/sleep.xen" is working for me now
> (modulo bugs which are obviously mine in origin)
> 
> I also think I'm beginning to get the hang of opam; 'switching' to
> 'system' to install stuff needed by oasis and then 'switching' back to
> the xen toolchain for actual builds.
> 
> Cheers,
> Dave
> 
> On Tue, Aug 28, 2012 at 11:37 PM, Anil Madhavapeddy <anil@xxxxxxxxxx> wrote:
>> I've added in the Xen rules to OASIS now too, so that you can do 'ocamlbuild 
>> sleep.xen' in ocaml-xenstore successfully.  My forked repository is at:
>> 
>> https://github.com/avsm/oasis/tree/add-xen
>> 
>> Dave, this works on ocaml-xenstore now if you regenerate myocamlbuild.ml 
>> with this OASIS (but dont forget to move the existing myocamlbuild.ml out of 
>> the way first).
>> 
>> I'm figuring out how to add this as a plugin, so it'll only get added when 
>> specified as 'Plugin: xen' in OASIS.   Also, we need the Executable field in 
>> _oasis to build stuff with a .xen suffix.
>> 
>> -anil
>> 
>> On 27 Aug 2012, at 15:50, Anil Madhavapeddy <anil@xxxxxxxxxx> wrote:
>> 
>>> This patch against darcs-oasis is sufficient to add a "native output obj" 
>>> target that outputs a standalone object file.  Just one more little rule 
>>> required to do the Xen objcopy/link, but this will also be useful for 
>>> kFreeBSD too.  This one is mainly for Dave as he's working on 
>>> ocaml-xenstore atm.
>>> 
>>> I'll submit an upstreamable patch shortly and have a Xen plugin to OASIS 
>>> that will make all our build pains waft away into a gentle summer breeze.
>>> 
>>> -anil
>>> 
>>> avsm@debian:~/src/darcs/oasis$ darcs diff
>>> diff -rN -u old-oasis/src/plugins/ocamlbuild/MyOCamlbuildBase.ml 
>>> new-oasis/src/plugins/ocamlbuild/MyOCamlbuildBase.ml
>>> --- old-oasis/src/plugins/ocamlbuild/MyOCamlbuildBase.ml        2012-08-24 
>>> 18:45:09.249486856 +0100
>>> +++ new-oasis/src/plugins/ocamlbuild/MyOCamlbuildBase.ml        2012-08-24 
>>> 18:45:09.301486856 +0100
>>> @@ -165,6 +165,15 @@
>>>            )
>>>            t.lib_c;
>>> 
>>> +          (* Add output_obj rules mapped to .nobj.o *)
>>> +          let native_output_obj x =
>>> +            OC.link_gen "cmx" "cmxa" !Options.ext_lib [!Options.ext_obj; 
>>> "cmi"]
>>> +              OC.ocamlopt_link_prog
>>> +              (fun tags -> tags++"ocaml"++"link"++"byte"++"output_obj") x
>>> +          in
>>> +          rule "ocaml: cmx* and o* -> .nobj.o" ~prod:"%.nobj.o" 
>>> ~deps:["%.cmx"; "%.o"]
>>> +            (native_output_obj "%.cmx" "%.nobj.o");
>>> +
>>>            (* Add flags *)
>>>            List.iter
>>>            (fun (tags, cond_specs) ->
>>> diff -rN -u old-oasis/src/plugins/ocamlbuild/MyOCamlbuildFindlib.ml 
>>> new-oasis/src/plugins/ocamlbuild/MyOCamlbuildFindlib.ml
>>> --- old-oasis/src/plugins/ocamlbuild/MyOCamlbuildFindlib.ml     2012-08-24 
>>> 18:45:09.249486856 +0100
>>> +++ new-oasis/src/plugins/ocamlbuild/MyOCamlbuildFindlib.ml     2012-08-24 
>>> 18:45:09.301486856 +0100
>>> @@ -86,6 +86,7 @@
>>> 
>>>        (* When one link an OCaml library/binary/package, one should use 
>>> -linkpkg *)
>>>        flag ["ocaml"; "link"; "program"] & A"-linkpkg";
>>> +        flag ["ocaml"; "link"; "output_obj"] & A"-linkpkg";
>>> 
>>>        (* For each ocamlfind package one inject the -package option when
>>>         * compiling, computing dependencies, generating documentation and
>>> diff -rN -u old-oasis/src/plugins/ocamlbuild/OCamlbuildPlugin.ml 
>>> new-oasis/src/plugins/ocamlbuild/OCamlbuildPlugin.ml
>>> --- old-oasis/src/plugins/ocamlbuild/OCamlbuildPlugin.ml        2012-08-24 
>>> 18:45:09.249486856 +0100
>>> +++ new-oasis/src/plugins/ocamlbuild/OCamlbuildPlugin.ml        2012-08-24 
>>> 18:45:09.301486856 +0100
>>> @@ -158,9 +158,9 @@
>>>                 let acc =
>>>                   match bs.bs_compiled_object with
>>>                     | Native ->
>>> -                         (target ".native") :: acc
>>> +                         (target ".native") :: (target ".nobj.o") ::  acc
>>>                     | Best when bool_of_string (is_native ()) ->
>>> -                         (target ".native") :: acc
>>> +                         (target ".native") :: (target ".nobj.o") :: acc
>>>                     | Byte
>>>                     | Best ->
>>>                         (target ".byte") :: acc
>>> @@ -928,11 +928,11 @@
>>>                   let ext =
>>>                     match bs.bs_compiled_object with
>>>                       | Best ->
>>> -                           "{native,byte}"
>>> +                           "{native,byte,nobj.o}"
>>>                       | Byte ->
>>>                           "byte"
>>>                       | Native ->
>>> -                           "native"
>>> +                           "native,nobj.o"
>>>                   in
>>>                     prepend_bs_path bs
>>>                       (OASISUnixPath.replace_extension
>> 
> 
> 
> 
> -- 
> Dave Scott
>