| 1 | /* This file implements the emacs_insque and emacs_remque functions, |
| 2 | copies of the insque and remque functions of BSD. They and all |
| 3 | their callers have been renamed to emacs_mumble to allow us to |
| 4 | include this file in the menu library on all systems. */ |
| 5 | |
| 6 | |
| 7 | struct qelem { |
| 8 | struct qelem *q_forw; |
| 9 | struct qelem *q_back; |
| 10 | char q_data[1]; |
| 11 | }; |
| 12 | |
| 13 | /* Insert ELEM into a doubly-linked list, after PREV. */ |
| 14 | |
| 15 | void |
| 16 | emacs_insque (elem, prev) |
| 17 | struct qelem *elem, *prev; |
| 18 | { |
| 19 | struct qelem *next = prev->q_forw; |
| 20 | prev->q_forw = elem; |
| 21 | if (next) |
| 22 | next->q_back = elem; |
| 23 | elem->q_forw = next; |
| 24 | elem->q_back = prev; |
| 25 | } |
| 26 | |
| 27 | /* Unlink ELEM from the doubly-linked list that it is in. */ |
| 28 | |
| 29 | emacs_remque (elem) |
| 30 | struct qelem *elem; |
| 31 | { |
| 32 | struct qelem *next = elem->q_forw; |
| 33 | struct qelem *prev = elem->q_back; |
| 34 | if (next) |
| 35 | next->q_back = prev; |
| 36 | if (prev) |
| 37 | prev->q_forw = next; |
| 38 | } |