Shared Object Question


 
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# 1  
Old 03-01-2011
Shared Object Question

Hello,

I am new to programming shared objects and I was hoping someone could tell me if what I want to do is possible, or else lead me in the right direction.

I have a main program that contains an abstract base class. I also have a subclass that I'm compiling as a shared object. The subclass includes headers that are in the main project, but the definitions are not included. When I dynamically load the subclass, it is has unresolved dependencies from those headers it included.

Is there a way to resolve those dependencies when I load the shared object into my main program (which has the definitions)?

Not sure if it's relevant, but I am using Qt to load the shared object.

Thanks,
- Derek
# 2  
Old 03-01-2011
Link in those dependencies when you create the library.
# 3  
Old 03-01-2011
Oh I see. Is it a problem that the definitions will be in both?
# 4  
Old 03-01-2011
Not from what I've seen.
# 5  
Old 03-02-2011
Thanks, it works like you said Corona668. However, there is one problem. One of the classes that is included in the project and the shared object had a static member and it seems that both have their own copy...

---------- Post updated at 01:25 AM ---------- Previous update was at 12:04 AM ----------

Ok so I found out from a site (can't post the URL because I don't have 5 posts...) that the shared object could have unresolved symbols that will be resolved when linked with my main application. You can do this if you compile your main application with -Wl,-export-dynamic to export the symbols.

However, I am still getting unresolved symbols after loading the library...
# 6  
Old 03-02-2011
Quote:
Originally Posted by dorik
Thanks, it works like you said Corona668. However, there is one problem. One of the classes that is included in the project and the shared object had a static member and it seems that both have their own copy...
That's weird. Perhaps your header is actually defining some things in the class, not just declaring them?
# 7  
Old 03-02-2011
Quote:
That's weird. Perhaps your header is actually defining some things in the class, not just declaring them?
Nope, just a class declaration. When I had it working by including the definitions in the project and the library, I set the static variable in the project and didn't set it in the library. The former had an an address and the latter was NULL.

Instead of including the definitions in both, I'd like to try the other approach I mentioned (exporting dynamic symbols in the project). This time, however, the library isn't even loading because of unresolved definitions. I used nm on the main executable and the unresolved symbols (from the library) mentioned in the error message are in there.
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