FD_CLR            426 include/ruby/win32.h #undef FD_CLR
FD_CLR            427 include/ruby/win32.h #define FD_CLR(f, s)		rb_w32_fdclr(f, s)
FD_CLR           2244 thread.c       #undef FD_CLR
FD_CLR           2249 thread.c       #define FD_CLR(i, f)	rb_fd_clr(i, f)
FD_CLR           2290 thread.c       #undef FD_CLR
FD_CLR           2295 thread.c       #define FD_CLR(i, f)	rb_fd_clr(i, f)
FD_CLR           1983 win32/win32.c  #undef FD_CLR