Open Radar

 
Summary:
.pch files are a great place to include .h files full of typedefs and constant declarations. Editing files included in .pch files causes syntax highlighting to fail in files that include symbols from the edited document. This makes me want to smash things.

Steps to Reproduce:
1) #include a file in your iOS app's .pch file (such as a Constants.h or Types.h file)
2) Edit and Save the contents of this file
3) Switch to a file that contains symbols that were defined in the file from step 2
4) Syntax Highlighting and Auto-Complete stop working
5) FUUUUUUUUUUUUUUUUU

Expected Results:
In step 4): Syntax highlighting and auto-complete works as it did before I edited the file in step 2). Hell, I'd even be happy if it didn't yet understand the symbols I'd changed/added.

Actual Results:
Syntax Highlighting fails, and I'm forced to delete the project's derived data directory, restart Xcode, and/or perform an indian rain chant in order to restore syntax highlighting.

Regression:

Xcode 4 is constantly in a quantum superposition of broken and working. However, I don't recall this particular behavior prior to 4.3. 

Notes:

When syntax highlighting and/or code completion fail, it makes me want to kick puppies. Obj-C is, by nature, very verbose. Don't make me type these obscenely long symbols by hand like a caveman.

Seriously, fix this shit.