#include <stdio.h>
#include <assert.h>
-#include <ccan/container_of/container_of.h>
+#include <ccan/tcon/tcon.h>
/**
* struct lstack_link - a stack link
};
/**
- * struct lstack - a stack
+ * struct lstack_ - a stack (internal type)
* @b: the top of the stack (NULL if empty)
*/
-struct lstack {
+struct lstack_ {
struct lstack_link *top;
};
/**
- * LSTACK - define and initialize an empty stack
- * @name: the name of the lstack.
+ * LSTACK - declare a stack
+ * @type: the type of elements in the stack
+ * @link: the field containing the lstack_link in @type
*
- * The LSTACK macro defines an lstack and initializes it to an empty
- * stack. It can be prepended by "static" to define a static lstack.
+ * The LSTACK macro declares an lstack. It can be prepended by
+ * "static" to define a static lstack. The stack begins in undefined
+ * state, you must either initialize with LSTACK_INIT, or call
+ * lstack_init() before using it.
*
* See also:
* lstack_init()
*
* Example:
- * LSTACK(my_stack);
+ * struct element {
+ * int value;
+ * struct lstack_link link;
+ * };
+ * LSTACK(struct element, link) my_stack;
+ */
+#define LSTACK(etype, link) \
+ TCON_WRAP(struct lstack_, \
+ TCON_CONTAINER(canary, etype, link))
+
+/**
+ * LSTACK_INIT - initializer for an empty stack
+ *
+ * The LSTACK_INIT macro returns a suitable initializer for a stack
+ * defined with LSTACK.
+ *
+ * Example:
+ * struct element {
+ * int value;
+ * struct lstack_link link;
+ * };
+ * LSTACK(struct element, link) my_stack = LSTACK_INIT;
*
* assert(lstack_empty(&my_stack));
*/
-#define LSTACK(name) \
- struct lstack name = { NULL, }
+#define LSTACK_INIT \
+ TCON_WRAP_INIT({ NULL, })
+
+/**
+ * lstack_entry - convert an lstack_link back into the structure containing it.
+ * @s: the stack
+ * @l: the lstack_link
+ *
+ * Example:
+ * struct element {
+ * int value;
+ * struct lstack_link link;
+ * } e;
+ * LSTACK(struct element, link) my_stack;
+ * assert(lstack_entry(&my_stack, &e.link) == &e);
+ */
+#define lstack_entry(s_, l_) tcon_container_of((s_), canary, (l_))
+
+
+/**
+ * lstack_init_from_top - initialize a stack with a given top element
+ * @s: the lstack to initialize
+ * @e: pointer to the top element of the new stack
+ *
+ * USE WITH CAUTION: This is for handling unusual cases where you have
+ * a pointer to an element in a previously constructed stack but can't
+ * conveniently pass around a normal struct lstack. Usually you
+ * should use lstack_init().
+ *
+ * Example:
+ * struct element {
+ * int value;
+ * struct lstack_link link;
+ * } e;
+ * LSTACK(struct element, link) stack1 = LSTACK_INIT;
+ * LSTACK(struct element, link) stack2;
+ *
+ * lstack_push(&stack1, &e);
+ *
+ * lstack_init_from_top(&stack2, lstack_top(&stack1));
+ */
+#define lstack_init_from_top(s_, e_) \
+ (lstack_init_(tcon_unwrap(s_), tcon_member_of((s_), canary, (e_))))
/**
* lstack_init - initialize a stack
* @h: the lstack to set to an empty stack
*
* Example:
- * struct lstack *sp = malloc(sizeof(*sp));
+ * struct element {
+ * int value;
+ * struct lstack_link link;
+ * };
+ * LSTACK(struct element, link) *sp = malloc(sizeof(*sp));
* lstack_init(sp);
*/
-static inline void lstack_init(struct lstack *s)
+#define lstack_init(s_) \
+ (lstack_init_(tcon_unwrap(s_), NULL))
+static inline void lstack_init_(struct lstack_ *s, struct lstack_link *top)
{
- s->top = NULL;
+ s->top = top;
}
/**
* @s: the stack
*
* If the stack is empty, returns true.
- *
- * Example:
- * assert(lstack_empty(sp));
*/
-static inline bool lstack_empty(const struct lstack *s)
+#define lstack_empty(s_) \
+ lstack_empty_(tcon_unwrap(s_))
+static inline bool lstack_empty_(const struct lstack_ *s)
{
return (s->top == NULL);
}
-/**
- * lstack_entry - convert an lstack_link back into the structure containing it.
- * @e: the lstack_link
- * @type: the type of the entry
- * @member: the lstack_link member of the type
- *
- * Example:
- * struct stacker {
- * char *name;
- * struct lstack_link sl;
- * } st;
- * assert(lstack_entry(&st.sl, struct stacker, sl) == &st);
- */
-#define lstack_entry(n, type, member) container_of_or_null(n, type, member)
-
/**
* lstack_top - get top entry in a stack
* @s: the stack
- * @type: the type of stack entries
- * @member: the lstack_link entry
*
* If the stack is empty, returns NULL.
*
* Example:
- * struct stacker *t;
+ * struct element *t;
*
- * t = lstack_top(sp, struct stacker, sl);
- * assert(lstack_pop(sp, struct stacker, sl) == t);
+ * t = lstack_top(sp);
+ * assert(lstack_pop(sp) == t);
*/
-#define lstack_top(s, type, member) \
- lstack_entry(lstack_top_((s)), type, member)
-static inline struct lstack_link *lstack_top_(const struct lstack *s)
+#define lstack_top(s_) \
+ lstack_entry((s_), lstack_top_(tcon_unwrap(s_)))
+static inline struct lstack_link *lstack_top_(const struct lstack_ *s)
{
return s->top;
}
* lstack_push - add an entry to the top of the stack
* @s: the stack to add the node to
* @e: the item to push
- * @member: the lstack_link field of *e
*
* The lstack_link does not need to be initialized; it will be overwritten.
*/
-#define lstack_push(s, e, member) \
- lstack_push_((s), &((e)->member))
-static inline void lstack_push_(struct lstack *s, struct lstack_link *e)
+#define lstack_push(s_, e_) \
+ lstack_push_(tcon_unwrap(s_), tcon_member_of((s_), canary, (e_)))
+static inline void lstack_push_(struct lstack_ *s, struct lstack_link *e)
{
e->down = lstack_top_(s);
s->top = e;
/**
* lstack_pop - remove and return the entry from the top of the stack
* @s: the stack
- * @type: the type of stack entries
- * @member: the lstack_link field of @type
*
* Note that this leaves the returned entry's link in an undefined
* state; it can be added to another stack, but not deleted again.
*/
-#define lstack_pop(s, type, member) \
- lstack_entry(lstack_pop_((s)), type, member)
-static inline struct lstack_link *lstack_pop_(struct lstack *s)
+#define lstack_pop(s_) \
+ lstack_entry((s_), lstack_pop_(tcon_unwrap((s_))))
+static inline struct lstack_link *lstack_pop_(struct lstack_ *s)
{
struct lstack_link *top;
- if (lstack_empty(s))
+ if (lstack_empty_(s))
return NULL;
top = lstack_top_(s);
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