X-Git-Url: http://git.ozlabs.org/?a=blobdiff_plain;f=ccan%2Ftlist%2Ftlist.h;h=83e66db8333874b15054b6d51e7063c0cc0b68d9;hb=9e92552b1b2a1b631bde1c379b9f2950725b1245;hp=9f62869b2b19c23c3fcb812ed2a6420a45a847a7;hpb=be2b527792d574ef8cf506d1a168d92354e23cc5;p=ccan

diff --git a/ccan/tlist/tlist.h b/ccan/tlist/tlist.h
index 9f62869b..83e66db8 100644
--- a/ccan/tlist/tlist.h
+++ b/ccan/tlist/tlist.h
@@ -9,17 +9,18 @@
  * @suffix: the name to use (struct tlist_@suffix)
  * @type: the type the list will contain (void for any type)
  *
- * This declares a structure "struct tlist_@suffix" to use for
- * lists containing this type.  The actual list can be accessed using
- * ".raw" or tlist_raw().
+ * This declares a structure "struct tlist_@suffix" to use for lists
+ * containing this type.  The actual list can be accessed using
+ * tlist_raw().  For maximum portability, place tlists embedded in
+ * structures as the last member.
  *
  * Example:
  *	// Defines struct tlist_children
  *	TLIST_TYPE(children, struct child);
  *	struct parent {
  *		const char *name;
- *		struct tlist_children children;
  *		unsigned int num_children;
+ *		struct tlist_children children;
  *	};
  *
  *	struct child {
@@ -29,12 +30,11 @@
  */
 #define TLIST_TYPE(suffix, type)			\
 	struct tlist_##suffix {				\
-		struct list_head raw;			\
-		TCON(type *canary);			\
+		TCON_WRAP(struct list_head, type *canary);	\
 	}
 
 /**
- * TLIST_INIT - initalizer for an empty tlist
+ * TLIST_INIT - initializer for an empty tlist
  * @name: the name of the list.
  *
  * Explicit initializer for an empty list.
@@ -45,7 +45,7 @@
  * Example:
  *	static struct tlist_children my_list = TLIST_INIT(my_list);
  */
-#define TLIST_INIT(name) { LIST_HEAD_INIT(name.raw) }
+#define TLIST_INIT(name) TCON_WRAP_INIT(LIST_HEAD_INIT(*tcon_unwrap(&name)))
 
 /**
  * tlist_check - check head of a list for consistency
@@ -74,7 +74,7 @@
  *	}
  */
 #define tlist_check(h, abortstr) \
-	list_check(&(h)->raw, (abortstr))
+	list_check(tcon_unwrap(h), (abortstr))
 
 /**
  * tlist_init - initialize a tlist
@@ -87,7 +87,7 @@
  *	tlist_init(&parent->children);
  *	parent->num_children = 0;
  */
-#define tlist_init(h) list_head_init(&(h)->raw)
+#define tlist_init(h) list_head_init(tcon_unwrap(h))
 
 /**
  * tlist_raw - unwrap the typed list and check the type
@@ -98,7 +98,7 @@
  * variable is of an unexpected type.  It is used internally where we
  * need to access the raw underlying list.
  */
-#define tlist_raw(h, expr) (&tcon_check((h), canary, (expr))->raw)
+#define tlist_raw(h, expr) tcon_unwrap(tcon_check((h), canary, (expr)))
 
 /**
  * tlist_add - add an entry at the start of a linked list.
@@ -173,37 +173,69 @@
  * Example:
  *	assert(tlist_empty(&parent->children) == (parent->num_children == 0));
  */
-#define tlist_empty(h) list_empty(&(h)->raw)
+#define tlist_empty(h) list_empty(tcon_unwrap(h))
 
 /**
  * tlist_top - get the first entry in a list
  * @h: the tlist
- * @type: the type of the entry
  * @member: the list_node member of the type
  *
  * If the list is empty, returns NULL.
  *
  * Example:
  *	struct child *first;
- *	first = tlist_top(&parent->children, struct child, list);
+ *	first = tlist_top(&parent->children, list);
+ *	if (!first)
+ *		printf("Empty list!\n");
  */
-#define tlist_top(h, type, member) \
-	list_top(tlist_raw((h), (type *)NULL), type, member)
+#define tlist_top(h, member)						\
+	((tcon_type((h), canary))					\
+	 list_top_(tcon_unwrap((h)),					\
+		   (char *)(&(h)->_tcon[0].canary->member) -		\
+		   (char *)((h)->_tcon[0].canary)))
 
 /**
  * tlist_tail - get the last entry in a list
  * @h: the tlist
- * @type: the type of the entry
  * @member: the list_node member of the type
  *
  * If the list is empty, returns NULL.
  *
  * Example:
  *	struct child *last;
- *	last = tlist_tail(&parent->children, struct child, list);
+ *	last = tlist_tail(&parent->children, list);
+ *	if (!last)
+ *		printf("Empty list!\n");
+ */
+#define tlist_tail(h, member)						\
+	((tcon_type((h), canary))					\
+	 list_tail_(tcon_unwrap(h),					\
+		    (char *)(&(h)->_tcon[0].canary->member) -		\
+		    (char *)((h)->_tcon[0].canary)))
+
+/**
+ * tlist_next - get the next entry in a list
+ * @h: the tlist
+ * @n: the list element
+ * @member: the list_node member of the type
+ *
+ * Returns the element of list @h immediately after @n, or NULL, if @n
+ * is the last element in the list.
+ */
+#define tlist_next(h, n, member)					\
+	list_next(tlist_raw((h), (n)), (n), member)
+
+/**
+ * tlist_prev - get the previous entry in a list
+ * @h: the tlist
+ * @n: the list element
+ * @member: the list_node member of the type
+ *
+ * Returns the element of list @h immediately before @n, or NULL, if
+ * @n is the first element in the list.
  */
-#define tlist_tail(h, type, member) \
-	list_tail(tlist_raw((h), (type *)NULL), type, member)
+#define tlist_prev(h, n, member)					\
+	list_prev(tlist_raw((h), (n)), (n), member)
 
 /**
  * tlist_for_each - iterate through a list.
@@ -221,6 +253,22 @@
 #define tlist_for_each(h, i, member)					\
 	list_for_each(tlist_raw((h), (i)), (i), member)
 
+/**
+ * tlist_for_each - iterate through a list backwards.
+ * @h: the tlist
+ * @i: an iterator of suitable type for this list.
+ * @member: the list_node member of @i
+ *
+ * This is a convenient wrapper to iterate @i over the entire list.  It's
+ * a for loop, so you can break and continue as normal.
+ *
+ * Example:
+ *	tlist_for_each_rev(&parent->children, child, list)
+ *		printf("Name: %s\n", child->name);
+ */
+#define tlist_for_each_rev(h, i, member)					\
+	list_for_each_rev(tlist_raw((h), (i)), (i), member)
+
 /**
  * tlist_for_each_safe - iterate through a list, maybe during deletion
  * @h: the tlist