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[PATCH 1/8] Add new FOREACH_FROM variants of the queue(3) FOREACH macros which can optionally start the traversal from a previously found element by passing the element in as "var". Passing a NULL "var" retains the same semantics as the regular FOREACH macros.
- From: Sebastian Huber <sebastian dot huber at embedded-brains dot de>
- To: newlib at sourceware dot org
- Date: Tue, 4 Apr 2017 10:34:42 +0200
- Subject: [PATCH 1/8] Add new FOREACH_FROM variants of the queue(3) FOREACH macros which can optionally start the traversal from a previously found element by passing the element in as "var". Passing a NULL "var" retains the same semantics as the regular FOREACH macros.
- Authentication-results: sourceware.org; auth=none
From: lstewart <lstewart@FreeBSD.org>
Kudos to phk for suggesting the "FROM" suffix instead of my original proposal.
Reviewed by: jhb (previous version), rpaulo
MFC after: 1 week
---
newlib/libc/include/sys/queue.h | 53 +++++++++++++++++++++++++++++++++++++++++
1 file changed, 53 insertions(+)
diff --git a/newlib/libc/include/sys/queue.h b/newlib/libc/include/sys/queue.h
index 4bc7dac..7a5bc79 100644
--- a/newlib/libc/include/sys/queue.h
+++ b/newlib/libc/include/sys/queue.h
@@ -88,9 +88,13 @@
* _PREV - + - +
* _LAST - - + +
* _FOREACH + + + +
+ * _FOREACH_FROM + + + +
* _FOREACH_SAFE + + + +
+ * _FOREACH_FROM_SAFE + + + +
* _FOREACH_REVERSE - - - +
+ * _FOREACH_REVERSE_FROM - - - +
* _FOREACH_REVERSE_SAFE - - - +
+ * _FOREACH_REVERSE_FROM_SAFE - - - +
* _INSERT_HEAD + + + +
* _INSERT_BEFORE - + - +
* _INSERT_AFTER + + + +
@@ -167,11 +171,21 @@ struct { \
(var); \
(var) = SLIST_NEXT((var), field))
+#define SLIST_FOREACH_FROM(var, head, field) \
+ for ((var) = ((var) ? (var) : SLIST_FIRST((head))); \
+ (var); \
+ (var) = SLIST_NEXT((var), field))
+
#define SLIST_FOREACH_SAFE(var, head, field, tvar) \
for ((var) = SLIST_FIRST((head)); \
(var) && ((tvar) = SLIST_NEXT((var), field), 1); \
(var) = (tvar))
+#define SLIST_FOREACH_FROM_SAFE(var, head, field, tvar) \
+ for ((var) = ((var) ? (var) : SLIST_FIRST((head))); \
+ (var) && ((tvar) = SLIST_NEXT((var), field), 1); \
+ (var) = (tvar))
+
#define SLIST_FOREACH_PREVPTR(var, varp, head, field) \
for ((varp) = &SLIST_FIRST((head)); \
((var) = *(varp)) != NULL; \
@@ -259,12 +273,21 @@ struct { \
(var); \
(var) = STAILQ_NEXT((var), field))
+#define STAILQ_FOREACH_FROM(var, head, field) \
+ for ((var) = ((var) ? (var) : STAILQ_FIRST((head))); \
+ (var); \
+ (var) = STAILQ_NEXT((var), field))
#define STAILQ_FOREACH_SAFE(var, head, field, tvar) \
for ((var) = STAILQ_FIRST((head)); \
(var) && ((tvar) = STAILQ_NEXT((var), field), 1); \
(var) = (tvar))
+#define STAILQ_FOREACH_FROM_SAFE(var, head, field, tvar) \
+ for ((var) = ((var) ? (var) : STAILQ_FIRST((head))); \
+ (var) && ((tvar) = STAILQ_NEXT((var), field), 1); \
+ (var) = (tvar))
+
#define STAILQ_INIT(head) do { \
STAILQ_FIRST((head)) = NULL; \
(head)->stqh_last = &STAILQ_FIRST((head)); \
@@ -394,11 +417,21 @@ struct { \
(var); \
(var) = LIST_NEXT((var), field))
+#define LIST_FOREACH_FROM(var, head, field) \
+ for ((var) = ((var) ? (var) : LIST_FIRST((head))); \
+ (var); \
+ (var) = LIST_NEXT((var), field))
+
#define LIST_FOREACH_SAFE(var, head, field, tvar) \
for ((var) = LIST_FIRST((head)); \
(var) && ((tvar) = LIST_NEXT((var), field), 1); \
(var) = (tvar))
+#define LIST_FOREACH_FROM_SAFE(var, head, field, tvar) \
+ for ((var) = ((var) ? (var) : LIST_FIRST((head))); \
+ (var) && ((tvar) = LIST_NEXT((var), field), 1); \
+ (var) = (tvar))
+
#define LIST_INIT(head) do { \
LIST_FIRST((head)) = NULL; \
} while (0)
@@ -531,21 +564,41 @@ struct { \
(var); \
(var) = TAILQ_NEXT((var), field))
+#define TAILQ_FOREACH_FROM(var, head, field) \
+ for ((var) = ((var) ? (var) : TAILQ_FIRST((head))); \
+ (var); \
+ (var) = TAILQ_NEXT((var), field))
+
#define TAILQ_FOREACH_SAFE(var, head, field, tvar) \
for ((var) = TAILQ_FIRST((head)); \
(var) && ((tvar) = TAILQ_NEXT((var), field), 1); \
(var) = (tvar))
+#define TAILQ_FOREACH_FROM_SAFE(var, head, field, tvar) \
+ for ((var) = ((var) ? (var) : TAILQ_FIRST((head))); \
+ (var) && ((tvar) = TAILQ_NEXT((var), field), 1); \
+ (var) = (tvar))
+
#define TAILQ_FOREACH_REVERSE(var, head, headname, field) \
for ((var) = TAILQ_LAST((head), headname); \
(var); \
(var) = TAILQ_PREV((var), headname, field))
+#define TAILQ_FOREACH_REVERSE_FROM(var, head, headname, field) \
+ for ((var) = ((var) ? (var) : TAILQ_LAST((head), headname)); \
+ (var); \
+ (var) = TAILQ_PREV((var), headname, field))
+
#define TAILQ_FOREACH_REVERSE_SAFE(var, head, headname, field, tvar) \
for ((var) = TAILQ_LAST((head), headname); \
(var) && ((tvar) = TAILQ_PREV((var), headname, field), 1); \
(var) = (tvar))
+#define TAILQ_FOREACH_REVERSE_FROM_SAFE(var, head, headname, field, tvar) \
+ for ((var) = ((var) ? (var) : TAILQ_LAST((head), headname)); \
+ (var) && ((tvar) = TAILQ_PREV((var), headname, field), 1); \
+ (var) = (tvar))
+
#define TAILQ_INIT(head) do { \
TAILQ_FIRST((head)) = NULL; \
(head)->tqh_last = &TAILQ_FIRST((head)); \
--
1.8.4.5