Qt pro file - file level attributes

[Goapher]

How to define file level attributes for one or more source file(s) (*.c, *.cpp, *.mm) in a .pro file?
I have a few files for which I do not want to use precompiled headers, or use a different set of compiler options. Can I mention them in the pro file?
The other way I see is to create a separate pro file and link them together. Is there any other simple way within a single pro file?

Thanks,
Gopinath

ps: I come from the world of Visual Studio - where things like these were pretty easily accomplished.. sorry for the n00b questions. :)