[PATCH] [RFC] python: gdb.Type: strip typedefs past pointers too

[Paul Bolle <pebolle@tiscali.nl>]

0) gdb.Type.strip_typedefs() stops stripping types if it encounters a
type that is a pointer to a typedef:

(gdb) ptype wchar_t
type = long int
(gdb) ptype wchar_t *
type = long int *
(gdb) python print gdb.lookup_type("wchar_t").strip_typedefs()
long int
(gdb) python print gdb.lookup_type("wchar_t").pointer().strip_typedefs()
wchar_t *

1) I drafted a patch (pasted below this message) that works around this
limitation:

(gdb) ptype wchar_t
type = long int
(gdb) ptype wchar_t *
type = long int *
(gdb) python print gdb.lookup_type("wchar_t").strip_typedefs()
long int
(gdb) python print gdb.lookup_type("wchar_t").pointer().strip_typedefs()
long int *

2) I'm not comfortable with the code I'm using here (ie, gdb's type
handling code) so I'd appreciate comments on this draft patch.


Paul Bolle
---
Currently gdb.Type.strip_typedefs() doesn't strip typedefs if it
encounters a type that is a pointer to a typedef. In those cases it
doesn't really behave as advertised (well, as I understand the
advertisement).

So learn strip_typedefs() to handle pointers to typedefs too.
---
 gdb/python/py-type.c |   23 ++++++++++++++++++++++-
 1 files changed, 22 insertions(+), 1 deletions(-)

diff --git a/gdb/python/py-type.c b/gdb/python/py-type.c
index 8232436..08602a1 100644
--- a/gdb/python/py-type.c
+++ b/gdb/python/py-type.c
@@ -267,8 +267,29 @@ static PyObject *
 typy_strip_typedefs (PyObject *self, PyObject *args)
 {
   struct type *type = ((type_object *) self)->type;
+  struct type *real_type;
+  int level = 0;
 
-  return type_to_type_object (check_typedef (type));
+  real_type = check_typedef (type);
+
+  while (TYPE_CODE (real_type) == TYPE_CODE_PTR ||
+	 TYPE_CODE (real_type) == TYPE_CODE_TYPEDEF)
+    {
+      if (TYPE_CODE (real_type) == TYPE_CODE_TYPEDEF)
+	{
+	  CHECK_TYPEDEF (real_type);
+	}
+      else
+       {
+	  real_type = TYPE_TARGET_TYPE (real_type);
+	  level++;
+	}
+    }
+
+  while (level--)
+    real_type = lookup_pointer_type (real_type);
+
+  return type_to_type_object (real_type);
 }
 
 /* Return an array type.  */
-- 
1.7.2.3