The effects of preprocessor in C are quite significant. Old DOS Turbo C had shown amount of lines compiled and the speed in the compilation progress window in the IDE. IIRC straight

    #include <stdio.h>
    #include <stdlib.h>
    int main(int argc, char**argv){
      puts("hello, world");
      return EXIT_SUCCESS;
    }

came to something ridiculous on the order of 100k lines.