Objective C, CABase.h file error

I hate Xcode 4! It crashes all the time and finally it gives me an error in CABase.h file whic开发者_如何学JAVAh is an library header file that I am not allowed to modify..

I don't even know how this file is broken. How to fix this problem? It complains like

 "Expected *before*
 Expected '=',',',';','asm' or '_attribute_' before 'extern'

Also, how can I completely remove Xcode on my Mac and re-install?

You probably just have a simple error, perhaps in a header which is included prior to CABase.h. Use a "divide and conquer" strategy to locate it.

To answer your last question:

$ sudo /Developer/Library/uninstall-devtools –mode=all

This happened to me just because I had the letter 's' at the beginning of one of my implementation files. I must have missed the cmd key when cmd+s for saving the file. Luckily, another compile error discovered this and removing the 's' fixed both errors.

For example,

s//
//  GraphingViewController.m