Re: [Caml-list] Link a .so/.dll dynamically

[Romain Bardou <bardou@lri.fr>]

Le 14/09/2011 18:56, Stéphane Glondu a écrit :
> On 09/14/2011 06:42 PM, Romain Bardou wrote:
>>>> Thanks, this solves the "native" part of my problem ! Now I need to
>>>> figure out how to link this .so file.
>>>
>>> You mean, the equivalent of dllmylib.so? There is no such file in native
>>> code: mylib.cmxs will contain the contents of mylib.cmxa and wrapper.o.
>>
>> No I mean the driver DLL for which Mylib is the binding. File
>> dllmylib.so is linked correctly, but binding.c includes api.h, which is
>> implemented in api.so, so I need to link with api.so as well. The whole
>> point of my original question is: how can I design the program such that
>> this api.so is loaded dynamically, because the user may want to choose a
>> different driver everytime, or even change driver during execution.
>
> That would be a -cclib option passed to ocamlmklib. It embeds a -lXXX
> option in the .cmxa that should be visible with a recent version of
> ocamlobjinfo. You can check the result by running ldd on the .cmxs file.
>
>
> Cheers,
>

Thanks, I tried the following combinations (with the bytecode version, 
not the native one):

-cclib -l$(DLLPATH)$(DLLNAME)$(DLLEXT)
-cclib -L$(DLLPATH) -cclib -l$(DLLNAME)$(DLLEXT)
-L$(DLLPATH) -cclib -l$(DLLNAME)$(DLLEXT)
-cclib -l$(DLLPATH)$(DLLNAME)
-cclib -L$(DLLPATH) -cclib -l$(DLLNAME)
-L$(DLLPATH) -cclib -l$(DLLNAME)

Where $(DLLPATH) is the full path to my driver, such as /usr/lib/, 
$(DLLNAME) is driver file name without the extension, such as driver, 
and $(DLLEXT) is the extension, such as .so, such that the full .so path 
is /usr/lib/driver.so.

None of them works; I still get the "undefined symbol" error. The option 
does appear with ocamlobjinfo though. For instance, here is the result 
of ocamlobjinfo on the .cma using the last command:

Extra C object files: -lcryptoki -ldriver
Extra C options: -L/usr/lib/
Extra dynamically-loaded libraries: -lcryptoki

Shouldn't the -ldriver option appear in the extra dynamically-loaded 
libraries as well?

I might try Jeremie's more direct approach if everything else fails.

Cheers,

-- 
Romain Bardou