The Xcode project generates Prefix.pch file automatically. When I deleted this file and tried to build, I got build error saying '*_Prefix.pch' file is missing.
- Is Prefix.pch file is a must for compiling with Xcode?
- How can I build without the Prefix.pch file?
In Xcode, go to your target's build settings (Command-Option-E, build tab) and uncheck Precompile Prefix Header (GCC_PRECOMPILE_PREFIX_HEADER). You can also remove the value of the Prefix Header setting if you wish.
Prefix headers are compiled and stored in a cache, and then automatically included in every file during compilation. This can speed up compilation, and lets you include a file without adding an import statement to every file using it. They are not required, and actually slow compilation whenever you change them.
Yes, you can compile and run the project without .pch file. In Xcode, go to your target's build settings (Command-Option-E, build tab) and uncheck Precompile Prefix Header (GCC_PRECOMPILE_PREFIX_HEADER). You can also remove the value of the Prefix Header setting if u want.
来源：https://stackoverflow.com/questions/4728225/is-it-ok-to-remove-prefix-pch-file-from-the-xcode-project