For the WX-based frontend, Source/Core/DolphinWX/Main.cpp, line 122. It uses the wxWidgets wxCmdLineParser helper class.
Good luck! :)
For future reference, you may want to consider using 'git grep' to search the source code. The folder structure is also relatively well-organized, so functionality is often self-evident.
Good luck! :)
For future reference, you may want to consider using 'git grep' to search the source code. The folder structure is also relatively well-organized, so functionality is often self-evident.