X-Git-Url: https://git.ozlabs.org/?a=blobdiff_plain;f=ccan%2Ftal%2Fautoptr%2Fautoptr.c;fp=ccan%2Ftal%2Fautoptr%2Fautoptr.c;h=5f22ef2c08c3272840017f53645a4e2bba6b0b33;hb=97ac5832db26f5f836fff979b08f01e17d7216bd;hp=0000000000000000000000000000000000000000;hpb=58277ab6c8b4dd6bb66638b88bd8505f46fdcb07;p=ccan

diff --git a/ccan/tal/autoptr/autoptr.c b/ccan/tal/autoptr/autoptr.c
new file mode 100644
index 00000000..5f22ef2c
--- /dev/null
+++ b/ccan/tal/autoptr/autoptr.c
@@ -0,0 +1,35 @@
+/* MIT (BSD) license - see LICENSE file for details */
+#include <ccan/tal/autoptr/autoptr.h>
+
+struct autonull {
+	void **pp;
+};
+
+static void autonull_remove(struct autonull *a);
+static void autonull_null_out(tal_t *p UNNEEDED, struct autonull *a)
+{
+	void **pp = a->pp;
+	tal_del_destructor(a, autonull_remove);
+	tal_free(a);
+	*pp = NULL;
+}
+
+static void autonull_remove(struct autonull *a)
+{
+	/* Don't NULL us out now. */
+	tal_del_destructor2(*a->pp, autonull_null_out, a);
+}
+
+struct autonull *autonull_set_ptr_(const tal_t *ctx, void *pp, const tal_t *p)
+{
+	struct autonull *a = tal(ctx, struct autonull);
+	a->pp = (void **)pp;
+	*a->pp = (void *)p;
+
+	/* If p is freed, NULL out a->pp */
+	tal_add_destructor2(*a->pp, autonull_null_out, a);
+
+	/* If they free autonull, it removes other destructor. */
+	tal_add_destructor(a, autonull_remove);
+	return a;
+}