list: add some iterator debug

Debugging use of unsafe iterators when you should have used the _safe
version sucks.  Add some DEBUG build support to catch and assert if
someone does that.

I didn't update the UPPERCASE verions of the iterators.  They should
probably be deprecated/removed.

Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Erik Faye-Lund <erik.faye-lund@collabora.com>

diff --git a/src/util/list.h b/src/util/list.h
index 09d1b4cae64c2aef2db3e018cc5dc7ec10ac1769..96e2f24695c221247686a3b3ffc7ddf727bc9805 100644 (file)
--- a/src/util/list.h
+++ b/src/util/list.h
@@ -43,6 +43,11 @@
 #include <assert.h>
 #include "c99_compat.h"
 
+#ifdef DEBUG
+#  define list_assert(cond, msg)  assert(cond && msg)
+#else
+#  define list_assert(cond, msg)  (void)(0 && (cond))
+#endif
 
 struct list_head
 {
@@ -212,21 +217,27 @@ static inline void list_validate(const struct list_head *list)
        pos = container_of(pos->member.prev, pos, member))
 
 #define list_for_each_entry(type, pos, head, member)                    \
-   for (type *pos = LIST_ENTRY(type, (head)->next, member);             \
+   for (type *pos = LIST_ENTRY(type, (head)->next, member),             \
+            *__next = LIST_ENTRY(type, pos->member.next, member);      \
        &pos->member != (head);                                         \
-       pos = LIST_ENTRY(type, pos->member.next, member))
+       pos = LIST_ENTRY(type, pos->member.next, member),               \
+       list_assert(pos == __next, "use _safe iterator"),               \
+       __next = LIST_ENTRY(type, __next->member.next, member))
 
 #define list_for_each_entry_safe(type, pos, head, member)               \
    for (type *pos = LIST_ENTRY(type, (head)->next, member),             \
             *__next = LIST_ENTRY(type, pos->member.next, member);      \
        &pos->member != (head);                                         \
        pos = __next,                                                   \
-        __next = LIST_ENTRY(type, __next->member.next, member))
+       __next = LIST_ENTRY(type, __next->member.next, member))
 
 #define list_for_each_entry_rev(type, pos, head, member)                \
-   for (type *pos = LIST_ENTRY(type, (head)->prev, member);             \
+   for (type *pos = LIST_ENTRY(type, (head)->prev, member),             \
+            *__prev = LIST_ENTRY(type, pos->member.prev, member);      \
        &pos->member != (head);                                         \
-       pos = LIST_ENTRY(type, pos->member.prev, member))
+       pos = LIST_ENTRY(type, pos->member.prev, member),               \
+       list_assert(pos == __prev, "use _safe iterator"),               \
+       __prev = LIST_ENTRY(type, __prev->member.prev, member))
 
 #define list_for_each_entry_safe_rev(type, pos, head, member)           \
    for (type *pos = LIST_ENTRY(type, (head)->prev, member),             \