reading a global external (C) char* in D2

[Lars T. Kyllingstad]

Graham Fawcett wrote:
> On Sun, 18 Apr 2010 19:14:33 +0200, Lars T. Kyllingstad wrote:
> 
>> Graham Fawcett wrote:
>>> Hi folks,
>>>
>>> I'm having trouble reading an external(C) global value in D2. I think
>>> I'm using __gshared properly to sidestep the TLS issues, but I'm still
>>> getting an incorrect result.
>>>
>>> [...]
>>>
>>> Am I doing something wrong?
>>>
>>> Thanks,
>>> Graham
>>
>> Try adding a second 'extern':
>>
>>    extern(C) extern __gshared char* gdbm_version;
> 
> That did it! Thank you. I have much to learn.


No problem. :)  I ran into the same issue myself a few weeks ago, and it 
took a while before I figured it out.  I believe the explanation is that

  - 'extern(C)' means that it is a C variable, i.e. its name isn't
    mangled like a D variable in the object file.

- 'extern' means that it's not a part of the current module, and
   has to be linked in from elsewhere.


-Lars