Question

I am realtivly new to the concept of dynamic loading and shared libraries. While I fully understand how dlopen() could be used to reference symbols in a shared library I have yet to fullt grasp what MacOS does behind the scenes when I don’t statically link against something. When adding a framework to Xcode I have the option to load it into my project or I can just provide some form of symlink to it(the actual implementation is obfuscated be the easy to use interface).

There after all I seem to need to do is import the header files that porvide and API to these frameworks and I can just invoke their symbols free of hassle. Can someone explain to me what I am actually doing, because it make no sense to me.

Answer 1

The sheet you’re referring to has nothing to do with the actual linking of the framework. The copy vs. link choice refers to how you want to include the framework in your Xcode project, not your app binary.

For system frameworks there really isn’t anything you need to do but import the headers.

For custom frameworks (your own or third-party) the framework must reside at the load path directory when your app launches. Typically the load path will point to your app bundle’s Frameworks (sub)directory, so you must add a Copy Files build phase that copies the framework to your app bundle’s Frameworks directory.

Remember to check out Apple’s Framework Programming Guide, especially the section on frameworks embedded in your app bundle.