/* SPDX-License-Identifier: LGPL-2.1+ */ #pragma once /*** This file is part of systemd. Copyright 2010 Lennart Poettering systemd is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. systemd is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with systemd; If not, see . ***/ /* The head of the linked list. Use this in the structure that shall * contain the head of the linked list */ #define LIST_HEAD(t,name) \ t *name /* The pointers in the linked list's items. Use this in the item structure */ #define LIST_FIELDS(t,name) \ t *name##_next, *name##_prev /* Initialize the list's head */ #define LIST_HEAD_INIT(head) \ do { \ (head) = NULL; } \ while (false) /* Initialize a list item */ #define LIST_INIT(name,item) \ do { \ typeof(*(item)) *_item = (item); \ assert(_item); \ _item->name##_prev = _item->name##_next = NULL; \ } while (false) /* Prepend an item to the list */ #define LIST_PREPEND(name,head,item) \ do { \ typeof(*(head)) **_head = &(head), *_item = (item); \ assert(_item); \ if ((_item->name##_next = *_head)) \ _item->name##_next->name##_prev = _item; \ _item->name##_prev = NULL; \ *_head = _item; \ } while (false) /* Append an item to the list */ #define LIST_APPEND(name,head,item) \ do { \ typeof(*(head)) *_tail; \ LIST_FIND_TAIL(name,head,_tail); \ LIST_INSERT_AFTER(name,head,_tail,item); \ } while (false) /* Remove an item from the list */ #define LIST_REMOVE(name,head,item) \ do { \ typeof(*(head)) **_head = &(head), *_item = (item); \ assert(_item); \ if (_item->name##_next) \ _item->name##_next->name##_prev = _item->name##_prev; \ if (_item->name##_prev) \ _item->name##_prev->name##_next = _item->name##_next; \ else { \ assert(*_head == _item); \ *_head = _item->name##_next; \ } \ _item->name##_next = _item->name##_prev = NULL; \ } while (false) /* Find the head of the list */ #define LIST_FIND_HEAD(name,item,head) \ do { \ typeof(*(item)) *_item = (item); \ if (!_item) \ (head) = NULL; \ else { \ while (_item->name##_prev) \ _item = _item->name##_prev; \ (head) = _item; \ } \ } while (false) /* Find the tail of the list */ #define LIST_FIND_TAIL(name,item,tail) \ do { \ typeof(*(item)) *_item = (item); \ if (!_item) \ (tail) = NULL; \ else { \ while (_item->name##_next) \ _item = _item->name##_next; \ (tail) = _item; \ } \ } while (false) /* Insert an item after another one (a = where, b = what) */ #define LIST_INSERT_AFTER(name,head,a,b) \ do { \ typeof(*(head)) **_head = &(head), *_a = (a), *_b = (b); \ assert(_b); \ if (!_a) { \ if ((_b->name##_next = *_head)) \ _b->name##_next->name##_prev = _b; \ _b->name##_prev = NULL; \ *_head = _b; \ } else { \ if ((_b->name##_next = _a->name##_next)) \ _b->name##_next->name##_prev = _b; \ _b->name##_prev = _a; \ _a->name##_next = _b; \ } \ } while (false) /* Insert an item before another one (a = where, b = what) */ #define LIST_INSERT_BEFORE(name,head,a,b) \ do { \ typeof(*(head)) **_head = &(head), *_a = (a), *_b = (b); \ assert(_b); \ if (!_a) { \ if (!*_head) { \ _b->name##_next = NULL; \ _b->name##_prev = NULL; \ *_head = _b; \ } else { \ typeof(*(head)) *_tail = (head); \ while (_tail->name##_next) \ _tail = _tail->name##_next; \ _b->name##_next = NULL; \ _b->name##_prev = _tail; \ _tail->name##_next = _b; \ } \ } else { \ if ((_b->name##_prev = _a->name##_prev)) \ _b->name##_prev->name##_next = _b; \ else \ *_head = _b; \ _b->name##_next = _a; \ _a->name##_prev = _b; \ } \ } while (false) #define LIST_JUST_US(name,item) \ (!(item)->name##_prev && !(item)->name##_next) \ #define LIST_FOREACH(name,i,head) \ for ((i) = (head); (i); (i) = (i)->name##_next) #define LIST_FOREACH_SAFE(name,i,n,head) \ for ((i) = (head); (i) && (((n) = (i)->name##_next), 1); (i) = (n)) #define LIST_FOREACH_BEFORE(name,i,p) \ for ((i) = (p)->name##_prev; (i); (i) = (i)->name##_prev) #define LIST_FOREACH_AFTER(name,i,p) \ for ((i) = (p)->name##_next; (i); (i) = (i)->name##_next) /* Iterate through all the members of the list p is included in, but skip over p */ #define LIST_FOREACH_OTHERS(name,i,p) \ for (({ \ (i) = (p); \ while ((i) && (i)->name##_prev) \ (i) = (i)->name##_prev; \ if ((i) == (p)) \ (i) = (p)->name##_next; \ }); \ (i); \ (i) = (i)->name##_next == (p) ? (p)->name##_next : (i)->name##_next) /* Loop starting from p->next until p->prev. p can be adjusted meanwhile. */ #define LIST_LOOP_BUT_ONE(name,i,head,p) \ for ((i) = (p)->name##_next ? (p)->name##_next : (head); \ (i) != (p); \ (i) = (i)->name##_next ? (i)->name##_next : (head))