-Weffc++ and Eigen library

Alec Jacobson

October 14, 2012

weblog/

I recently tried to make use of the -Weffc++ gcc compiler flag in my project. Unfortunately Eigen is not developed with these warnings in mind. So when I tried to use it I got a gazillion warnings from including Eigen headers. My solution was to move all Eigen includes to a single header (EigenConvenience.h), which looks something like this:

#ifdef __GNUC__
// This is how it should be done
#  if __GNUC__ >= 4
#    if __GNUC_MINOR__ >= 6
#      pragma GCC diagnostic push
#      pragma GCC diagnostic ignored "-Weffc++"
#    endif
#  endif
// This is a hack
#  pragma GCC system_header
#endif

// Include all eigen headers here, e.g.
#include <Eigen/Dense>

#ifdef __GNUC__
#  if __GNUC__ >= 4
#    if __GNUC_MINOR__ >= 6
#      pragma GCC diagnostic pop
#    endif
#  endif
#endif