February 15th, 2016
A dSYM file contains your project’s debugging symbols. If you profile your project in Instruments and see memory addresses instead of function names in the call tree view, the problem may be Instruments not finding your project’s dSYM file.
Choose Instrument > Call Tree Data Mining > Locate dSYM to find a dSYM file. An Open panel opens for you to locate your project’s dSYM file.
Where is your project’s dSYM file? It’s usually located in the same directory as the application bundle of the release version of your project. Debug builds normally do not have dSYM files. The debugging symbols are inside the application’s executable code. Refer to my Changing Xcode’s Build Location article if you need help finding your project’s application bundle.
In Xcode 9 choose File > Symbols to locate the dSYM file. More detailed information can be found in the following article: