Compiling wxWindows using KDevelop

[Mingyi Liu]

Hi, I'm a new user of KDevelop.I was trying to use a cross-platform library
wxWindows the other day, but during compilation I was told I need to set
preprocessor definition of platform specification (__WXGTK__ or
__WXWINDOWS__ etc). I checked out the build settings for KDevelop but
cannot find out where I add the preprocessor definition so the compilation
can
work. Does anyone know? Thanks in advance.

BTW, I tried to get help from wxWindows mailing list too, but it's either
that they didn't know how to do it, or they were too engaged in a book
making topic they're having now. So I still have no idea how I can do it.