X-Git-Url: http://git.ozlabs.org/?p=ccan;a=blobdiff_plain;f=ccan%2Fforeach%2Fforeach.c;h=879ab86e99c3df3a71a6d0b1dea49297d6818562;hp=70040ee986a5116bb407ea5ebc3ab703d51abd98;hb=6a8d296f9383dd25ec381e2ab136a33823d140e5;hpb=5b115ea9392ca30ce5f0bbeb18389ea9aaea7421;ds=sidebyside

diff --git a/ccan/foreach/foreach.c b/ccan/foreach/foreach.c
index 70040ee9..879ab86e 100644
--- a/ccan/foreach/foreach.c
+++ b/ccan/foreach/foreach.c
@@ -1,3 +1,4 @@
+/* Licensed under LGPLv3+ - see LICENSE file for details */
 #include <ccan/foreach/foreach.h>
 #if !HAVE_COMPOUND_LITERALS || !HAVE_FOR_LOOP_DECLARATION
 #include <ccan/list/list.h>
@@ -12,19 +13,28 @@ struct iter_info {
 	struct list_node list;
 	const void *index;
 	unsigned int i, num;
+	bool onstack;
 };
 
+/* Is pointer still downstack from some other onstack var? */
+static bool on_stack(const void *ptr, const void *onstack)
+{
+#if HAVE_STACK_GROWS_UPWARDS
+	return ptr < onstack;
+#else
+	return ptr > onstack;
+#endif
+}
+
 static void free_old_iters(const void *index)
 {
 	struct iter_info *i, *next;
 
 	list_for_each_safe(&iters, i, next, list) {
 		/* If we're re-using an index, free the old one.
-		 * Otherwise, if it's past i on the stack, it's old.  Don't
-		 * assume stack direction, but we know index is downstack. */
+		 * Otherwise, discard if it's passed off stack. */
 		if (i->index == index
-		    || (((uintptr_t)index < (uintptr_t)&i)
-			== ((uintptr_t)&i < (uintptr_t)i->index))) {
+		    || (i->onstack && !on_stack(i->index, &i))) {
 			list_del(&i->list);
 			free(i);
 		}
@@ -47,6 +57,7 @@ static struct iter_info *new_iter(const void *index)
 	struct iter_info *info = malloc(sizeof *info);
 	info->index = index;
 	info->i = info->num = 0;
+	info->onstack = on_stack(index, &info);
 	list_add(&iters, &info->list);
 	return info;
 };