+/*
+ * Copyright (c) 2007, 2010 Todd C. Miller <Todd.Miller@courtesan.com>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#ifndef _SUDO_LIST_H
+#define _SUDO_LIST_H
+
+/*
+ * Convenience macro for declaring a list head.
+ */
+#define TQ_DECLARE(n) \
+struct n##_list { \
+ struct n *first; \
+ struct n *last; \
+};
+
+/*
+ * Foreach loops: forward and reverse
+ */
+#undef tq_foreach_fwd
+#define tq_foreach_fwd(h, v) \
+ for ((v) = (h)->first; (v) != NULL; (v) = (v)->next)
+
+#undef tq_foreach_rev
+#define tq_foreach_rev(h, v) \
+ for ((v) = (h)->last; (v) != NULL; (v) = (v)->prev)
+
+/*
+ * Init a list head.
+ */
+#undef tq_init
+#define tq_init(h) do { \
+ (h)->first = NULL; \
+ (h)->last = NULL; \
+} while (0)
+
+/*
+ * Simple macros to avoid exposing first/last and prev/next.
+ */
+#undef tq_empty
+#define tq_empty(h) ((h)->first == NULL)
+
+#undef tq_first
+#define tq_first(h) ((h)->first)
+
+#undef tq_last
+#define tq_last(h) ((h)->last)
+
+#undef list_next
+#define list_next(e) ((e)->next)
+
+#undef list_prev
+#define list_prev(e) ((e)->prev)
+
+/*
+ * Prototypes for list.c
+ */
+void *tq_pop(void *);
+void tq_append(void *, void *);
+void tq_remove(void *, void *);
+void list_append(void *, void *);
+void list2tq(void *, void *);
+
+#endif /* _SUDO_LIST_H */