Meaning of XCode clang error “not found in architecture i386”

问题

I'm not sure what these errors mean or what to do about them. I moved a folder and some files around in Finder, and then added them back to my project.

Undefined symbols for architecture i386:
  "_OBJC_CLASS_$_IASKSettingsReader", referenced from:
      objc-class-ref in IASKAppSettingsViewController.o
  "_OBJC_CLASS_$_IASKSettingsStoreUserDefaults", referenced from:
      objc-class-ref in IASKAppSettingsViewController.o
  "_OBJC_CLASS_$_IASKSpecifierValuesViewController", referenced from:
      objc-class-ref in IASKAppSettingsViewController.o
  "_OBJC_CLASS_$_IASKPSTitleValueSpecifierViewCell", referenced from:
      objc-class-ref in IASKAppSettingsViewController.o
ld: symbol(s) not found for architecture i386
clang: error: linker command failed with exit code 1 (use -v to see invocation)

This is followed by these error messages (which I can't copy as text)

I had just compiled successfully before the files were moved and added.

回答1:

The class IASKSettingsReader/IASKSettingsStoreUserDefaults/... is not being linked. Please check that you have it included on your Xcode project and in the Build Phases of your project under Compile Sources, if not add them.

来源：https://stackoverflow.com/questions/9551503/meaning-of-xcode-clang-error-not-found-in-architecture-i386