Hello.

In ruby there's very common idiom to check if current file is "main" file:

  if __FILE__ == $0
    # do something here (usually run unit tests)
  end

I'd like to do something similar in C after reading gcc documentation I've figured that it should work like this:

  #if __FILE__ == __BASE_FILE__
    // Do stuff
  #endif

the only problem is after I try this:

$ gcc src/bitmap_index.c -std=c99 -lm && ./a.out 
src/bitmap_index.c:173:1: error: token ""src/bitmap_index.c"" is not valid in preprocessor expressions

Am I using #if wrong?