[PATCHv4 02/12] scripts/gdb: Provide kernel list item generators

[Kieran Bingham]

Facilitate linked-list items by providing a generator to return
the dereferenced, and type-cast objects from a kernel linked list

CC: Jeff Mahoney <jeffm@xxxxxxxx>

Signed-off-by: Kieran Bingham <kieran.bingham@xxxxxxxxxx>
---
Changes since v1:
 - items function removed, and replaced with Jeff Mahoney's cleaner
   implementations of list_for_each, and list_for_each_entry

Changes since v3:
 - GdbError strings formatted on single line
 - list_head type corrected to head.type
 - .format() style preferred over %
---
 scripts/gdb/linux/lists.py | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/scripts/gdb/linux/lists.py b/scripts/gdb/linux/lists.py
index 3a3775bc162b..2f335fbd86fd 100644
--- a/scripts/gdb/linux/lists.py
+++ b/scripts/gdb/linux/lists.py
@@ -18,6 +18,27 @@ from linux import utils
 list_head = utils.CachedType("struct list_head")
 
 
+def list_for_each(head):
+    if head.type == list_head.get_type().pointer():
+        head = head.dereference()
+    elif head.type != list_head.get_type():
+        raise gdb.GdbError("Must be struct list_head not {}"
+                           .format(head.type))
+
+    node = head['next'].dereference()
+    while node.address != head.address:
+        yield node.address
+        node = node['next'].dereference()
+
+
+def list_for_each_entry(head, gdbtype, member):
+    for node in list_for_each(head):
+        if node.type != list_head.get_type().pointer():
+            raise TypeError("Type {} found. Expected struct list_head *."
+                            .format(node.type))
+        yield utils.container_of(node, gdbtype, member)
+
+
 def list_check(head):
     nb = 0
     if (head.type == list_head.get_type().pointer()):
-- 
2.5.0