X-Git-Url: https://git.ozlabs.org/?p=ccan;a=blobdiff_plain;f=ccan%2Flist%2Flist.c;h=d876f21e7b06b0bd06a38fdd89b5b35ff6d62d31;hp=b72f8f67d87705c7af25af874ec08269c6080e41;hb=a94286219597d8123188aaff0aaa55dba5104a05;hpb=650c775ff00cccd03fc84e7789a03c51d9839004

diff --git a/ccan/list/list.c b/ccan/list/list.c
index b72f8f67..d876f21e 100644
--- a/ccan/list/list.c
+++ b/ccan/list/list.c
@@ -1,33 +1,42 @@
 #include <stdio.h>
 #include <stdlib.h>
-#include "list/list.h"
+#include "list.h"
 
-struct list_head *list_check(struct list_head *h, const char *abortstr)
+static void *corrupt(const char *abortstr,
+		     const struct list_node *head,
+		     const struct list_node *node,
+		     unsigned int count)
 {
-	struct list_node *n, *p;
-	int count = 0;
-
-	if (h->n.next == &h->n) {
-		if (h->n.prev != &h->n) {
-			if (!abortstr)
-				return NULL;
-			fprintf(stderr, "%s: prev corrupt in empty %p\n",
-				abortstr, h);
-			abort();
-		}
-		return h;
+	if (abortstr) {
+		fprintf(stderr,
+			"%s: prev corrupt in node %p (%u) of %p\n",
+			abortstr, node, count, head);
+		abort();
 	}
+	return NULL;
+}
+
+struct list_node *list_check_node(const struct list_node *node,
+				  const char *abortstr)
+{
+	const struct list_node *p, *n;
+	int count = 0;
 
-	for (p = &h->n, n = h->n.next; n != &h->n; p = n, n = n->next) {
+	for (p = node, n = node->next; n != node; p = n, n = n->next) {
 		count++;
-		if (n->prev != p) {
-			if (!abortstr)
-				return NULL;
-			fprintf(stderr,
-				"%s: prev corrupt in node %p (%u) of %p\n",
-				abortstr, n, count, h);
-			abort();
-		}
+		if (n->prev != p)
+			return corrupt(abortstr, node, n, count);
 	}
-	return h;
+	/* Check prev on head node. */
+	if (node->prev != p)
+		return corrupt(abortstr, node, node, 0);
+
+	return (struct list_node *)node;
+}
+
+struct list_head *list_check(const struct list_head *h, const char *abortstr)
+{
+	if (!list_check_node(&h->n, abortstr))
+		return NULL;
+	return (struct list_head *)h;
 }