commit https://github.com/vim/vim/commit/86edef664efccbfe685906c854b9cdd04e56f2d5 Author: Bram Moolenaar <Bram@vim.org> Date: Sun Mar 13 18:07:30 2016 +0100 patch 7.4.1557 Problem: Windows cannot be identified. Solution: Add a unique window number to each window and functions to use it.

/* auto/if_perl.c */
int perl_enabled(int verbose);
void perl_end(void);
void msg_split(char_u *s, int attr);
void perl_win_free(win_T *wp);
void perl_buf_free(buf_T *bp);
void ex_perl(exarg_T *eap);
void do_perleval(char_u *str, typval_T *rettv);
void ex_perldo(exarg_T *eap);