[PATCH] dtc: fix for_each_*() to skip first object if deleted

[Stephen Warren]

From: Stephen Warren <swarren at nvidia.com>

The previous definition of e.g. for_each_*() would always include the
very first object within the list of processed labels, irrespective of
whether it was marked deleted, since the deleted flag was not checked
on the first object, but only on any "next" object.

Fix for_each_*() to call skip_deleted_*() prior to every loop iteration,
including the first, i.e. as part of the for loop test expression rather
than as part of the increment statement, to correct this.

Incidentally, this change is why commit 45013d8 dtc: "Add ability to
delete nodes and properties" only caused two "make checkm" failures;
only two tests actually use multiple labels on the same property or
node. With this current change applied, but commit 317a5d9 "dtc: zero
out new label objects" reverted, "make checkm" fails 29 times; i.e.
for every test that uses any labels at all.

Signed-off-by: Stephen Warren <swarren at nvidia.com>
---
Rob, Grant, now that you're listed as maintainers for the Linux kernel's
copy of dtc, will you automatically apply patches there as they are
accepted into upstream dtc, or should I still create "backport" patches
and send them to you separately?

 dtc.h |   23 +++++++++++------------
 1 files changed, 11 insertions(+), 12 deletions(-)

diff --git a/dtc.h b/dtc.h
index d501c86..88da264 100644
--- a/dtc.h
+++ b/dtc.h
@@ -161,47 +161,46 @@ struct node {
 	struct label *labels;
 };
 
-static inline struct label *for_each_label_next(struct label *l)
+static inline struct label *skip_deleted_labels(struct label *l)
 {
-	do {
+	while (l && l->deleted)
 		l = l->next;
-	} while (l && l->deleted);
 
 	return l;
 }
 
 #define for_each_label(l0, l) \
-	for ((l) = (l0); (l); (l) = for_each_label_next(l))
+	for ((l) = (l0); ((l) = skip_deleted_labels(l)); (l) = (l)->next)
 
 #define for_each_label_withdel(l0, l) \
 	for ((l) = (l0); (l); (l) = (l)->next)
 
-static inline struct property *for_each_property_next(struct property *p)
+static inline struct property *skip_deleted_properties(struct property *p)
 {
-	do {
+	while (p && p->deleted)
 		p = p->next;
-	} while (p && p->deleted);
 
 	return p;
 }
 
 #define for_each_property(n, p) \
-	for ((p) = (n)->proplist; (p); (p) = for_each_property_next(p))
+	for ((p) = (n)->proplist; ((p) = skip_deleted_properties(p)); \
+		(p) = (p)->next)
 
 #define for_each_property_withdel(n, p) \
 	for ((p) = (n)->proplist; (p); (p) = (p)->next)
 
-static inline struct node *for_each_child_next(struct node *c)
+static inline struct node *skip_deleted_children(struct node *c)
 {
-	do {
+	while (c && c->deleted)
 		c = c->next_sibling;
-	} while (c && c->deleted);
 
 	return c;
 }
 
 #define for_each_child(n, c) \
-	for ((c) = (n)->children; (c); (c) = for_each_child_next(c))
+	for ((c) = (n)->children; ((c) = skip_deleted_children(c)); \
+		(c) = (c)->next_sibling)
 
 #define for_each_child_withdel(n, c) \
 	for ((c) = (n)->children; (c); (c) = (c)->next_sibling)
-- 
1.7.0.4