extern void enq_end(uschar *);
extern BOOL enq_start(uschar *, unsigned);
#ifndef DISABLE_EVENT
-extern uschar *event_raise(uschar *, const uschar *, uschar *, int *);
+extern uschar *event_raise(const uschar *, const uschar *, const uschar *, int *);
extern void msg_event_raise(const uschar *, const address_item *);
#endif
extern int host_item_get_port(host_item *);
extern void host_mask(int, int *, int);
extern int host_name_lookup(void);
-extern int host_nmtoa(int, int *, int, uschar *, int);
+extern int host_nmtoa(int, const int *, int, uschar *, int);
extern uschar *host_ntoa(int, const void *, uschar *, int *);
extern int host_scan_for_local_hosts(host_item *, host_item **, BOOL *);
extern BOOL readconf_depends(driver_instance *, uschar *);
extern void readconf_driver_init(uschar *, driver_instance **,
driver_info *, int, void *, int, optionlist *, int);
-extern uschar *readconf_find_option(void *);
+extern const uschar *readconf_find_option(void *);
extern void readconf_main(BOOL);
extern void readconf_options_from_list(optionlist *, unsigned, const uschar *, uschar *);
extern BOOL readconf_print(const uschar *, const uschar *, BOOL);