lib/ccan/list/list.c

   1 /* Licensed under LGPLv2.1+ - see LICENSE file for details */
   2 #include <stdio.h>
   3 #include <stdlib.h>
   4 #include "list.h"
   5
   6 static void *corrupt(const char *abortstr,
   7                      const struct ccan_list_node *head,
   8                      const struct ccan_list_node *node,
   9                      unsigned int count)
  10 {
  11         if (abortstr) {
  12                 fprintf(stderr,
  13                         "%s: prev corrupt in node %p (%u) of %p\n",
  14                         abortstr, node, count, head);
  15                 abort();
  16         }
  17         return NULL;
  18 }
  19
  20 struct ccan_list_node *ccan_list_check_node(const struct ccan_list_node *node,
  21                                   const char *abortstr)
  22 {
  23         const struct ccan_list_node *p, *n;
  24         int count = 0;
  25
  26         for (p = node, n = node->next; n != node; p = n, n = n->next) {
  27                 count++;
  28                 if (n->prev != p)
  29                         return corrupt(abortstr, node, n, count);
  30         }
  31         /* Check prev on head node. */
  32         if (node->prev != p)
  33                 return corrupt(abortstr, node, node, 0);
  34
  35         return (struct ccan_list_node *)node;
  36 }
  37
  38 struct ccan_list_head *ccan_list_check(const struct ccan_list_head *h, const char *abortstr)
  39 {
  40         if (!ccan_list_check_node(&h->n, abortstr))
  41                 return NULL;
  42         return (struct ccan_list_head *)h;
  43 }