commit https://github.com/vim/vim/commit/864293abb72d62604d8d6b458addfb43c14230c3 Author: Bram Moolenaar <Bram@vim.org> Date: Thu Jun 2 13:40:04 2016 +0200 patch 7.4.1871 Problem: Appending to the quickfix list while the quickfix window is open is very slow. Solution: Do not delete all the lines, only append the new ones. Avoid using a window while updating the list. (closes #841)

/* 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);