When using project files and makefiles directly to build wxWidgets, options are configurable in the file "wx/XXX/setup.h" where XXX is the required platform (such as msw, motif, gtk, mac). Some settings are a matter of taste, some help with platform-specific problems, and others can be set to minimize the size of the library. Please see the setup.h file and install.txt files for details on configuration.
When using the 'configure' script to configure wxWidgets (on Unix and other platforms where configure is available), the corresponding setup.h files are generated automatically along with suitable makefiles. When using the RPM packages for installing wxWidgets on Linux, a correct setup.h is shipped in the package and this must not be changed.