X-Git-Url: https://git.ozlabs.org/?p=ccan;a=blobdiff_plain;f=ccan%2Ftlist%2Ftlist.h;h=937a834c0184fb4d54928ca57db9668a929b1f8c;hp=7e43fe29ee8a8ed664374ec8b59ca82376f988f1;hb=919b97d6e573eb794d7819f1af8da29023d6b193;hpb=74257cee33ae3033f961d5f22a0313b8cb1b18d4

diff --git a/ccan/tlist/tlist.h b/ccan/tlist/tlist.h
index 7e43fe29..937a834c 100644
--- a/ccan/tlist/tlist.h
+++ b/ccan/tlist/tlist.h
@@ -2,8 +2,8 @@
 #ifndef CCAN_TLIST_H
 #define CCAN_TLIST_H
 #include <ccan/list/list.h>
+#include <ccan/tcon/tcon.h>
 
-#if HAVE_FLEXIBLE_ARRAY_MEMBER
 /**
  * TLIST_TYPE - declare a typed list type (struct tlist)
  * @suffix: the name to use (struct tlist_@suffix)
@@ -27,31 +27,12 @@
  *		struct list_node list;
  *	};
  */
-#define TLIST_TYPE(suffix, type)					\
-	struct tlist_##suffix {						\
-		struct list_head raw;					\
-		const type *tcheck[];					\
+#define TLIST_TYPE(suffix, type)			\
+	struct tlist_##suffix {				\
+		struct list_head raw;			\
+		TCON(type *canary);			\
 	}
 
-/**
- * tlist_raw - access the raw list inside a typed list head.
- * @h: the head of the typed list (struct tlist_@suffix)
- * @test_var: a pointer to the expected element type.
- *
- * This elaborate macro usually causes the compiler to emit a warning
- * if the variable is of an unexpected type.  It is used internally
- * where we need to access the raw underlying list.
- */
-#define tlist_raw(h, test_var) \
-	(sizeof((h)->tcheck[0] == (test_var)) ? &(h)->raw : &(h)->raw)
-#else
-#define TLIST_TYPE(suffix, type)					\
-	struct tlist_##suffix {						\
-		struct list_head raw;					\
-	}
-#define tlist_raw(h, test_var) (&(h)->raw)
-#endif
-
 /**
  * TLIST_INIT - initalizer for an empty tlist
  * @name: the name of the list.
@@ -108,6 +89,17 @@
  */
 #define tlist_init(h) list_head_init(&(h)->raw)
 
+/**
+ * tlist_raw - unwrap the typed list and check the type
+ * @h: the tlist
+ * @expr: the expression to check the type against (not evaluated)
+ *
+ * This macro usually causes the compiler to emit a warning if the
+ * 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)
+
 /**
  * tlist_add - add an entry at the start of a linked list.
  * @h: the tlist to add the node to
@@ -186,32 +178,40 @@
 /**
  * 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_(&(h)->raw,						\
+		   (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, type, member) \
-	list_tail(tlist_raw((h), (type *)NULL), type, member)
+#define tlist_tail(h, member)						\
+	((tcon_type((h), canary))					\
+	 list_tail_(&(h)->raw,						\
+		    (char *)(&(h)->_tcon[0].canary->member) -		\
+		    (char *)((h)->_tcon[0].canary)))
 
 /**
  * tlist_for_each - iterate through a list.
@@ -229,6 +229,22 @@
 #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