How to add a library (libSomeRandomlib.so) to a project....??

Question

Ok, so I've been trying to get CERN's ROOT program/libraries to work in an xcode project for a while, but I'm running into one really weird error, and I think I may just not know how to add a library to a project correctly.
Suppose I create a new Xcode C++ command line tool project. I hit Build and go, and it gives me a nice little Hello World! in the console, just as it should. If I then click on the project in Groups & Files, go to Project>Add to Project..., and choose, say, libCint.so, from my root/lib directory, and click ok, then click Build & Go, I get an error in the console:
dyld: Library not loaded: @rpath/libCint.so
Referenced from: /Users/paulthompson/Documents/Programming/Build Products/Debug/LibraryIncludeTest
Reason: image not found
sharedlibrary apply-load-rules all
Data Formatters temporarily unavailable, will re-try after a 'continue'. (Cannot call into the loader at present, it is locked.)
My assumption is that either I'm missing a step in the process of adding a library, or else there is something jacked up with the libraries themselves. Anyone have any advice?
Thanks,
Paul
EDIT* Oh, I should mention that the actuall binary that gets built after adding the library WILL execute properly in the Finder, or from terminal, just not with the Build & Go, or Go commands from within xcode.
Message was edited by: TraxusIV

Answer 1

TraxusIV wrote:
Results of otool:
LibraryIncludeTest:
@rpath/libCint.so (compatibility version 0.0.0, current version 0.0.0)
/usr/lib/libstdc++.6.dylib (compatibility version 7.0.0, current version 7.9.0)
/usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 123.0.0)
Macintosh-9:Debug paulthompson$ otool -L /Applications/CERNRoot/root/lib/libCint.so
/Applications/CERNRoot/root/lib/libCint.so:
@rpath/libCint.so (compatibility version 0.0.0, current version 0.0.0)
/usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 125.2.0)
/usr/lib/libstdc++.6.dylib (compatibility version 7.0.0, current version 7.9.0)
I honestly don't know much about @rpath. I found this page that explains it a bit more: http://blogs.sun.com/dipol/entry/dynamiclibraries_rpath_andmac
So, since I don't want to deploy with the environment variable set, I should ask, what IS the correct, MacOS X way to do it?
The best way to find that is to look at how Apple does it. They put frameworks in /System/Library/Frameworks and regular shared libraries in the standard places. You can do the same. Put your frameworks into /Library/Frameworks and your shared libraries into /usr/local-based paths.
If you want to create stand-alone executables that can be installed via drag-n-drop, you can put shared libraries inside the application bundle. If your shared libraries/frameworks are elsewhere, you will need some sort of installer to get them installed.
I've been sifting through Apple's developer documentation but I have yet to find a concise, straightforward explanation of how to add shared libraries. I'm horribly confused at this point. Is there a good tutorial available anywhere for both the general unix case of linking to dylibs and .so's, and the Mac specific case?
Hopefully someone else knows an answer for this one.
*EDIT* I do already have the variable defined both in ~/.MacOS/environment.plist and also in Xcode as an additional user variable.
I'm not sure about the whole RPATH thing. Setting environment.plist will define environment variables for use in the Finder, but that is really a hack. There are better ways to do it, but if you are porting some open-source programs, that may be the only way. You should be able to define those variables in Xcode. You have to selected the debug executable under "Exectuables"