/* Licensed under BSD-MIT - see LICENSE file for details */
#ifndef CCAN_LIST_H
#define CCAN_LIST_H
+//#define CCAN_LIST_DEBUG 1
#include <stdbool.h>
#include <assert.h>
+#include <ccan/str/str.h>
#include <ccan/container_of/container_of.h>
#include <ccan/check_type/check_type.h>
struct list_node *list_check_node(const struct list_node *n,
const char *abortstr);
+#define LIST_LOC __FILE__ ":" stringify(__LINE__)
#ifdef CCAN_LIST_DEBUG
-#define list_debug(h) list_check((h), __func__)
-#define list_debug_node(n) list_check_node((n), __func__)
+#define list_debug(h, loc) list_check((h), loc)
+#define list_debug_node(n, loc) list_check_node((n), loc)
#else
-#define list_debug(h) (h)
-#define list_debug_node(n) (n)
+#define list_debug(h, loc) (h)
+#define list_debug_node(n, loc) (n)
#endif
/**
h->n.next = h->n.prev = &h->n;
}
+/**
+ * list_node_init - initialize a list_node
+ * @n: the list_node to link to itself.
+ *
+ * You don't need to use this normally! But it lets you list_del(@n)
+ * safely.
+ */
+static inline void list_node_init(struct list_node *n)
+{
+ n->next = n->prev = n;
+}
+
+/**
+ * list_add_after - add an entry after an existing node in a linked list
+ * @h: the list_head to add the node to (for debugging)
+ * @p: the existing list_node to add the node after
+ * @n: the new list_node to add to the list.
+ *
+ * The existing list_node must already be a member of the list.
+ * The new list_node does not need to be initialized; it will be overwritten.
+ *
+ * Example:
+ * struct child c1, c2, c3;
+ * LIST_HEAD(h);
+ *
+ * list_add_tail(&h, &c1.list);
+ * list_add_tail(&h, &c3.list);
+ * list_add_after(&h, &c1.list, &c2.list);
+ */
+#define list_add_after(h, p, n) list_add_after_(h, p, n, LIST_LOC)
+static inline void list_add_after_(struct list_head *h,
+ struct list_node *p,
+ struct list_node *n,
+ const char *abortstr)
+{
+ n->next = p->next;
+ n->prev = p;
+ p->next->prev = n;
+ p->next = n;
+ (void)list_debug(h, abortstr);
+}
+
/**
* list_add - add an entry at the start of a linked list.
* @h: the list_head to add the node to
* list_add(&parent->children, &child->list);
* parent->num_children++;
*/
-static inline void list_add(struct list_head *h, struct list_node *n)
+#define list_add(h, n) list_add_(h, n, LIST_LOC)
+static inline void list_add_(struct list_head *h,
+ struct list_node *n,
+ const char *abortstr)
{
- n->next = h->n.next;
- n->prev = &h->n;
- h->n.next->prev = n;
- h->n.next = n;
- (void)list_debug(h);
+ list_add_after_(h, &h->n, n, abortstr);
+}
+
+/**
+ * list_add_before - add an entry before an existing node in a linked list
+ * @h: the list_head to add the node to (for debugging)
+ * @p: the existing list_node to add the node before
+ * @n: the new list_node to add to the list.
+ *
+ * The existing list_node must already be a member of the list.
+ * The new list_node does not need to be initialized; it will be overwritten.
+ *
+ * Example:
+ * list_head_init(&h);
+ * list_add_tail(&h, &c1.list);
+ * list_add_tail(&h, &c3.list);
+ * list_add_before(&h, &c3.list, &c2.list);
+ */
+#define list_add_before(h, p, n) list_add_before_(h, p, n, LIST_LOC)
+static inline void list_add_before_(struct list_head *h,
+ struct list_node *p,
+ struct list_node *n,
+ const char *abortstr)
+{
+ n->next = p;
+ n->prev = p->prev;
+ p->prev->next = n;
+ p->prev = n;
+ (void)list_debug(h, abortstr);
}
/**
* list_add_tail(&parent->children, &child->list);
* parent->num_children++;
*/
-static inline void list_add_tail(struct list_head *h, struct list_node *n)
+#define list_add_tail(h, n) list_add_tail_(h, n, LIST_LOC)
+static inline void list_add_tail_(struct list_head *h,
+ struct list_node *n,
+ const char *abortstr)
{
- n->next = &h->n;
- n->prev = h->n.prev;
- h->n.prev->next = n;
- h->n.prev = n;
- (void)list_debug(h);
+ list_add_before_(h, &h->n, n, abortstr);
}
/**
* Example:
* assert(list_empty(&parent->children) == (parent->num_children == 0));
*/
-static inline bool list_empty(const struct list_head *h)
+#define list_empty(h) list_empty_(h, LIST_LOC)
+static inline bool list_empty_(const struct list_head *h, const char* abortstr)
{
- (void)list_debug(h);
+ (void)list_debug(h, abortstr);
return h->n.next == &h->n;
}
+/**
+ * list_empty_nodebug - is a list empty (and don't perform debug checks)?
+ * @h: the list_head
+ *
+ * If the list is empty, returns true.
+ * This differs from list_empty() in that if CCAN_LIST_DEBUG is set it
+ * will NOT perform debug checks. Only use this function if you REALLY
+ * know what you're doing.
+ *
+ * Example:
+ * assert(list_empty_nodebug(&parent->children) == (parent->num_children == 0));
+ */
+#ifndef CCAN_LIST_DEBUG
+#define list_empty_nodebug(h) list_empty(h)
+#else
+static inline bool list_empty_nodebug(const struct list_head *h)
+{
+ return h->n.next == &h->n;
+}
+#endif
+
/**
* list_del - delete an entry from an (unknown) linked list.
* @n: the list_node to delete from the list.
* another list, but not deleted again.
*
* See also:
- * list_del_from()
+ * list_del_from(), list_del_init()
*
* Example:
* list_del(&child->list);
* parent->num_children--;
*/
-static inline void list_del(struct list_node *n)
+#define list_del(n) list_del_(n, LIST_LOC)
+static inline void list_del_(struct list_node *n, const char* abortstr)
{
- (void)list_debug_node(n);
+ (void)list_debug_node(n, abortstr);
n->next->prev = n->prev;
n->prev->next = n->next;
#ifdef CCAN_LIST_DEBUG
#endif
}
+/**
+ * list_del_init - delete a node, and reset it so it can be deleted again.
+ * @n: the list_node to be deleted.
+ *
+ * list_del(@n) or list_del_init() again after this will be safe,
+ * which can be useful in some cases.
+ *
+ * See also:
+ * list_del_from(), list_del()
+ *
+ * Example:
+ * list_del_init(&child->list);
+ * parent->num_children--;
+ */
+#define list_del_init(n) list_del_init_(n, LIST_LOC)
+static inline void list_del_init_(struct list_node *n, const char *abortstr)
+{
+ list_del_(n, abortstr);
+ list_node_init(n);
+}
+
/**
* list_del_from - delete an entry from a known linked list.
* @h: the list_head the node is in.
list_del(n);
}
+/**
+ * list_swap - swap out an entry from an (unknown) linked list for a new one.
+ * @o: the list_node to replace from the list.
+ * @n: the list_node to insert in place of the old one.
+ *
+ * Note that this leaves @o in an undefined state; it can be added to
+ * another list, but not deleted/swapped again.
+ *
+ * See also:
+ * list_del()
+ *
+ * Example:
+ * struct child x1, x2;
+ * LIST_HEAD(xh);
+ *
+ * list_add(&xh, &x1.list);
+ * list_swap(&x1.list, &x2.list);
+ */
+#define list_swap(o, n) list_swap_(o, n, LIST_LOC)
+static inline void list_swap_(struct list_node *o,
+ struct list_node *n,
+ const char* abortstr)
+{
+ (void)list_debug_node(o, abortstr);
+ *n = *o;
+ n->next->prev = n;
+ n->prev->next = n;
+#ifdef CCAN_LIST_DEBUG
+ /* Catch use-after-del. */
+ o->next = o->prev = NULL;
+#endif
+}
+
/**
* list_entry - convert a list_node back into the structure containing it.
* @n: the list_node
return (const char *)h->n.next - off;
}
+/**
+ * list_pop - remove the first entry in a list
+ * @h: the list_head
+ * @type: the type of the entry
+ * @member: the list_node member of the type
+ *
+ * If the list is empty, returns NULL.
+ *
+ * Example:
+ * struct child *one;
+ * one = list_pop(&parent->children, struct child, list);
+ * if (!one)
+ * printf("Empty list!\n");
+ */
+#define list_pop(h, type, member) \
+ ((type *)list_pop_((h), list_off_(type, member)))
+
+static inline const void *list_pop_(const struct list_head *h, size_t off)
+{
+ struct list_node *n;
+
+ if (list_empty(h))
+ return NULL;
+ n = h->n.next;
+ list_del(n);
+ return (const char *)n - off;
+}
+
/**
* list_tail - get the last entry in a list
* @h: the list_head
* printf("Name: %s\n", child->name);
*/
#define list_for_each_rev(h, i, member) \
- for (i = container_of_var(list_debug(h)->n.prev, i, member); \
+ for (i = container_of_var(list_debug(h, LIST_LOC)->n.prev, i, member); \
&i->member != &(h)->n; \
i = container_of_var(i->member.prev, i, member))
#define list_for_each_safe(h, i, nxt, member) \
list_for_each_safe_off(h, i, nxt, list_off_var_(i, member))
+/**
+ * list_next - get the next entry in a list
+ * @h: the list_head
+ * @i: a pointer to an entry in the list.
+ * @member: the list_node member of the structure
+ *
+ * If @i was the last entry in the list, returns NULL.
+ *
+ * Example:
+ * struct child *second;
+ * second = list_next(&parent->children, first, list);
+ * if (!second)
+ * printf("No second child!\n");
+ */
+#define list_next(h, i, member) \
+ ((list_typeof(i))list_entry_or_null(list_debug(h, \
+ __FILE__ ":" stringify(__LINE__)), \
+ (i)->member.next, \
+ list_off_var_((i), member)))
+
+/**
+ * list_prev - get the previous entry in a list
+ * @h: the list_head
+ * @i: a pointer to an entry in the list.
+ * @member: the list_node member of the structure
+ *
+ * If @i was the first entry in the list, returns NULL.
+ *
+ * Example:
+ * first = list_prev(&parent->children, second, list);
+ * if (!first)
+ * printf("Can't go back to first child?!\n");
+ */
+#define list_prev(h, i, member) \
+ ((list_typeof(i))list_entry_or_null(list_debug(h, \
+ __FILE__ ":" stringify(__LINE__)), \
+ (i)->member.prev, \
+ list_off_var_((i), member)))
+
+/**
+ * list_append_list - empty one list onto the end of another.
+ * @to: the list to append into
+ * @from: the list to empty.
+ *
+ * This takes the entire contents of @from and moves it to the end of
+ * @to. After this @from will be empty.
+ *
+ * Example:
+ * struct list_head adopter;
+ *
+ * list_append_list(&adopter, &parent->children);
+ * assert(list_empty(&parent->children));
+ * parent->num_children = 0;
+ */
+#define list_append_list(t, f) list_append_list_(t, f, \
+ __FILE__ ":" stringify(__LINE__))
+static inline void list_append_list_(struct list_head *to,
+ struct list_head *from,
+ const char *abortstr)
+{
+ struct list_node *from_tail = list_debug(from, abortstr)->n.prev;
+ struct list_node *to_tail = list_debug(to, abortstr)->n.prev;
+
+ /* Sew in head and entire list. */
+ to->n.prev = from_tail;
+ from_tail->next = &to->n;
+ to_tail->next = &from->n;
+ from->n.prev = to_tail;
+
+ /* Now remove head. */
+ list_del(&from->n);
+ list_head_init(from);
+}
+
+/**
+ * list_prepend_list - empty one list into the start of another.
+ * @to: the list to prepend into
+ * @from: the list to empty.
+ *
+ * This takes the entire contents of @from and moves it to the start
+ * of @to. After this @from will be empty.
+ *
+ * Example:
+ * list_prepend_list(&adopter, &parent->children);
+ * assert(list_empty(&parent->children));
+ * parent->num_children = 0;
+ */
+#define list_prepend_list(t, f) list_prepend_list_(t, f, LIST_LOC)
+static inline void list_prepend_list_(struct list_head *to,
+ struct list_head *from,
+ const char *abortstr)
+{
+ struct list_node *from_tail = list_debug(from, abortstr)->n.prev;
+ struct list_node *to_head = list_debug(to, abortstr)->n.next;
+
+ /* Sew in head and entire list. */
+ to->n.next = &from->n;
+ from->n.prev = &to->n;
+ to_head->prev = from_tail;
+ from_tail->next = to_head;
+
+ /* Now remove head. */
+ list_del(&from->n);
+ list_head_init(from);
+}
+
/**
* list_for_each_off - iterate through a list of memory regions.
* @h: the list_head
* printf("Name: %s\n", child->name);
*/
#define list_for_each_off(h, i, off) \
- for (i = list_node_to_off_(list_debug(h)->n.next, (off)); \
+ for (i = list_node_to_off_(list_debug(h, LIST_LOC)->n.next, \
+ (off)); \
list_node_from_off_((void *)i, (off)) != &(h)->n; \
i = list_node_to_off_(list_node_from_off_((void *)i, (off))->next, \
(off)))
* printf("Name: %s\n", child->name);
*/
#define list_for_each_safe_off(h, i, nxt, off) \
- for (i = list_node_to_off_(list_debug(h)->n.next, (off)), \
+ for (i = list_node_to_off_(list_debug(h, LIST_LOC)->n.next, \
+ (off)), \
nxt = list_node_to_off_(list_node_from_off_(i, (off))->next, \
(off)); \
list_node_from_off_(i, (off)) != &(h)->n; \
(container_off_var(var, member) + \
check_type(var->member, struct list_node))
+#if HAVE_TYPEOF
+#define list_typeof(var) typeof(var)
+#else
+#define list_typeof(var) void *
+#endif
+
+/* Returns member, or NULL if at end of list. */
+static inline void *list_entry_or_null(const struct list_head *h,
+ const struct list_node *n,
+ size_t off)
+{
+ if (n == &h->n)
+ return NULL;
+ return (char *)n - off;
+}
#endif /* CCAN_LIST_H */
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