Dynamic loading of shared libraries.

[Jacob Carlborg]

On 2011-06-13 18:19, Andrei Alexandrescu wrote:
> On 6/13/11 10:33 AM, Jens Mueller wrote:
>> Andrei Alexandrescu wrote:
>>> On 6/13/11 4:27 AM, Jens Mueller wrote:
>>>> Steve Teale wrote:
>>>>> Can DMD D2/Linux do this yet?
>>>>
>>>> dmd can't do it yet. But if all you want is to link a against a shared
>>>> library you can try the following:
>>>>
>>>> 1. Create a shared library
>>>> $ gcc -m64 -fPIC -shared shared.c -o libshared.so
>>>>
>>>> 2. Building (without linking using dmd)
>>>> $ dmd -m64 -c dynamic.d -ofdynamic.o
>>>>
>>>> 3. Use gcc as linker
>>>> $ gcc -m64 dynamic.o /path/to//libphobos2.a -L. -lshared -lrt -o
>>>> dynamic
>>>>
>>>> 4. Execute
>>>> $ ./dynamic
>>>> Hello from shared
>>>>
>>>> I attached the files shared.c and dynamic.d, if you want to try
>>>> yourself.
>>>>
>>>> Jens
>>>
>>> Jens,
>>>
>>>
>>> Two questions - first, what steps do we need to take to convince the
>>> linker call from within dmd to work as above?
>>
>> Never thought about that. Just tried.
>> $ dmd -m64 dynamic.o /path/to/libphobos2.a -L-L. -L-lshared -L-lrt
>> -ofdynamic
>> works.
>
> Great. Wonder why the path to Phobos is still needed - does using -L
> preclude all implicit uses of it?
>
>>> Second, how about the converse - loading a shared library from a
>>> program written in either C or D?
>>
>> Don't know exactly what you mean. As far as I know dmd is not able to
>> generate shared libraries. Is that your question?
>
> Yah, I was wondering if it's just PIC generation or something extra.
>
>
> Andrei

The runtime needs a couple of changes as well, for example module info, 
i.e. module constructors, exception handling tables and so on.

-- 
/Jacob Carlborg