Question

If I could find a way to do something similar to this, I could cut out hundreds of lines of code in my application, and dramatically increase maintainability. Anyone have any ideas?

#include <stdio.h>

int main( )
{
  #define include_all_files(root)   \
            #include #root "1.h"    \
            #include #root "2.h"    \
            #include #root "3.h"    \
            #include #root "4.h"

  include_all_files( first_library )
  include_all_files( second_library )
  include_all_files( third_library )

  return 0;
}

EDIT:

I appreciate the responses, my example seems to be causing a misdirection in effort, so here is the problem I am actually trying to solve:

I am implementing a finite state machine. Through naming conventions, I have gotten it to be as simple to add a state as:

  STATE(initial_screen)
    #include "initial_screen.state"
  END_STATE

  STATE(login)
    #include "login.state"
  END_STATE

However, if I could answer the original question, I could refactor this down to something as simple as:

  ADD_STATE(initial_screen)
  ADD_STATE(login)

This is because the file name and the state name, and all the underlying wiring and everything else all follow similar conventions. However, I cannot figure out how to implement the include file based on the token received in a macro.

Answer 1

Unfortunately, this is beyond the capabilities of the C preprocessor.

Have you considered using something like m4 instead?