Re: [Caml-list] Static linking via Ctypes?

[David Sheets <sheets@alum.mit.edu>]

On Tue, Mar 25, 2014 at 3:11 PM, Dan Benjamin <dbenjamin@janestreet.com> wrote:
> I am passing -force_load, as well as --whole-archive (in case that
> makes a difference), and I have the following situation:
>
> - readelf -s shows that the function that I wish to call exists in the
> executable
> - running the executable results in Dl.DL_error("undefined symbol")
> for the same function, corresponding to the line of code where I call
> Foreign.foreign.
>
> Am I going about this wrongly?

I did

<https://github.com/dsheets/ocaml-unix-unistd/blob/master/lib/unix_unistd_stubs.c#L61>

and

<https://github.com/dsheets/ocaml-unix-unistd/blob/master/lib/ctypes/unix_unistd.ml#L32>

to require a static link without stub generation in addition to
ocamlmklib on the .ml and .o files.

Unfortunately, this is not very portable (or sane). I believe that
<https://github.com/ocamllabs/ocaml-ctypes/issues/96> may be related.

Hope this helps,

David

> On Tue, Mar 25, 2014 at 11:04 AM, Bruno Deferrari <utizoc@gmail.com> wrote:
>> On Tue, Mar 25, 2014 at 11:54 AM,  <dbenjamin@janestreet.com> wrote:
>>> I'm using Ctypes to interface with a dynamic library, but in addition to the
>>> interface provided the library I have some helper functions (written in C,
>>> against the same library) that I'd also like to call via Ctypes.  Is there any
>>> way to achieve this via static linking or am I required to build another
>>> shared object?
>>>
>>
>> Static linking works. I was in this same situation yesterday, and
>> adding the .o files that were generated from C sources to the linking
>> step did the trick.
>>
>> If you are trying to link a .a file, you may have to pass the
>> -force_load option to the linker to force it to include it, otherwise
>> it may see that none of the symbols there are being referenced
>> directly and decide to not include it (this happened to me when using
>> clang in OSX).
>>
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>>
>>
>>
>> --
>> BD
>
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