-/* Licensed under LGPLv2.1+ - see LICENSE file for details */
+/* 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 - an entry in a doubly-linked list
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
/**
* 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);
+ (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);
+ (void)list_debug(h, 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.
* 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
* Example:
* struct child *first;
* first = list_top(&parent->children, struct child, list);
+ * if (!first)
+ * printf("Empty list!\n");
+ */
+#define list_top(h, type, member) \
+ ((type *)list_top_((h), list_off_(type, member)))
+
+static inline const void *list_top_(const struct list_head *h, size_t off)
+{
+ if (list_empty(h))
+ return NULL;
+ 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_top(h, type, member) \
- (list_empty(h) ? NULL : list_entry((h)->n.next, type, member))
+#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
* Example:
* struct child *last;
* last = list_tail(&parent->children, struct child, list);
+ * if (!last)
+ * printf("Empty list!\n");
*/
#define list_tail(h, type, member) \
- (list_empty(h) ? NULL : list_entry((h)->n.prev, type, member))
+ ((type *)list_tail_((h), list_off_(type, member)))
+
+static inline const void *list_tail_(const struct list_head *h, size_t off)
+{
+ if (list_empty(h))
+ return NULL;
+ return (const char *)h->n.prev - off;
+}
/**
* list_for_each - iterate through a list.
- * @h: the list_head
+ * @h: the list_head (warning: evaluated multiple times!)
* @i: the structure containing the list_node
* @member: the list_node member of the structure
*
* printf("Name: %s\n", child->name);
*/
#define list_for_each(h, i, member) \
- for (i = container_of_var(list_debug(h)->n.next, i, member); \
- &i->member != &(h)->n; \
- i = container_of_var(i->member.next, i, member))
+ list_for_each_off(h, i, list_off_var_(i, member))
/**
* list_for_each_rev - iterate through a list backwards.
* 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) \
- for (i = container_of_var(list_debug(h)->n.next, i, member), \
- nxt = container_of_var(i->member.next, i, member); \
- &i->member != &(h)->n; \
- i = nxt, nxt = container_of_var(i->member.next, i, 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
+ * @i: the pointer to a memory region wich contains list node data.
+ * @off: offset(relative to @i) at which list node data resides.
+ *
+ * This is a low-level wrapper to iterate @i over the entire list, used to
+ * implement all oher, more high-level, for-each constructs. It's a for loop,
+ * so you can break and continue as normal.
+ *
+ * WARNING! Being the low-level macro that it is, this wrapper doesn't know
+ * nor care about the type of @i. The only assumtion made is that @i points
+ * to a chunk of memory that at some @offset, relative to @i, contains a
+ * properly filled `struct node_list' which in turn contains pointers to
+ * memory chunks and it's turtles all the way down. Whith all that in mind
+ * remember that given the wrong pointer/offset couple this macro will
+ * happilly churn all you memory untill SEGFAULT stops it, in other words
+ * caveat emptor.
+ *
+ * It is worth mentioning that one of legitimate use-cases for that wrapper
+ * is operation on opaque types with known offset for `struct list_node'
+ * member(preferably 0), because it allows you not to disclose the type of
+ * @i.
+ *
+ * Example:
+ * list_for_each_off(&parent->children, child,
+ * offsetof(struct child, list))
+ * printf("Name: %s\n", child->name);
+ */
+#define list_for_each_off(h, i, 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)))
+
+/**
+ * list_for_each_safe_off - iterate through a list of memory regions, maybe
+ * during deletion
+ * @h: the list_head
+ * @i: the pointer to a memory region wich contains list node data.
+ * @nxt: the structure containing the list_node
+ * @off: offset(relative to @i) at which list node data resides.
+ *
+ * For details see `list_for_each_off' and `list_for_each_safe'
+ * descriptions.
+ *
+ * Example:
+ * list_for_each_safe_off(&parent->children, child,
+ * next, offsetof(struct child, list))
+ * 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, 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; \
+ i = nxt, \
+ nxt = list_node_to_off_(list_node_from_off_(i, (off))->next, \
+ (off)))
+
+
+/* Other -off variants. */
+#define list_entry_off(n, type, off) \
+ ((type *)list_node_from_off_((n), (off)))
+
+#define list_head_off(h, type, off) \
+ ((type *)list_head_off((h), (off)))
+
+#define list_tail_off(h, type, off) \
+ ((type *)list_tail_((h), (off)))
+
+#define list_add_off(h, n, off) \
+ list_add((h), list_node_from_off_((n), (off)))
+
+#define list_del_off(n, off) \
+ list_del(list_node_from_off_((n), (off)))
+
+#define list_del_from_off(h, n, off) \
+ list_del_from(h, list_node_from_off_((n), (off)))
+
+/* Offset helper functions so we only single-evaluate. */
+static inline void *list_node_to_off_(struct list_node *node, size_t off)
+{
+ return (void *)((char *)node - off);
+}
+static inline struct list_node *list_node_from_off_(void *ptr, size_t off)
+{
+ return (struct list_node *)((char *)ptr + off);
+}
+
+/* Get the offset of the member, but make sure it's a list_node. */
+#define list_off_(type, member) \
+ (container_off(type, member) + \
+ check_type(((type *)0)->member, struct list_node))
+
+#define list_off_var_(var, member) \
+ (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 */