Remove more uses of explicit reference counting in Python

This changes some more place in the Python code to use gdbpy_ref
rather than explicit reference counting.  While doing this I found a
latent bug in typy_fields_items -- it was not checking for errors in
one spot.  I also changed valpy_dealloc to use Py_XDECREF rather than
an explicit "if".

gdb/ChangeLog
2019-01-03  Tom Tromey  <tom@tromey.com>

	* python/py-value.c (valpy_dealloc): Use Py_XDECREF.
	* python/py-type.c (typy_fields_items): Use gdbpy_ref.
	* python/py-progspace.c (pspy_set_printers): Use gdbpy_ref.
	(pspy_set_frame_filters, pspy_set_frame_unwinders)
	(pspy_set_type_printers): Likewise.
	* python/py-function.c (fnpy_init): Use gdbpy_ref.
	* python/py-cmd.c (cmdpy_init): Use gdbpy_ref.
	* python/py-objfile.c (objfpy_set_printers): Use gdbpy_ref.
	(objfpy_set_frame_filters, objfpy_set_frame_unwinders)
	(objfpy_set_type_printers): Likewise.

1 files changed, 5 insertions, 6 deletions

diff --git a/gdb/python/py-function.c b/gdb/python/py-function.c
index b254ab7..dbd5649 100644
--- a/gdb/python/py-function.c
+++ b/gdb/python/py-function.c
@@ -109,7 +109,8 @@ fnpy_init (PyObject *self, PyObject *args, PyObject *kwds)
 
   if (! PyArg_ParseTuple (args, "s", &name))
     return -1;
-  Py_INCREF (self);
+
+  gdbpy_ref<> self_ref = gdbpy_ref<>::new_reference (self);
 
   if (PyObject_HasAttrString (self, "__doc__"))
     {
@@ -120,17 +121,15 @@ fnpy_init (PyObject *self, PyObject *args, PyObject *kwds)
 	    {
 	      docstring = python_string_to_host_string (ds_obj.get ());
 	      if (docstring == NULL)
-		{
-		  Py_DECREF (self);
-		  return -1;
-		}
+		return -1;
 	    }
 	}
     }
   if (! docstring)
     docstring.reset (xstrdup (_("This function is not documented.")));
 
-  add_internal_function (name, docstring.release (), fnpy_call, self);
+  add_internal_function (name, docstring.release (), fnpy_call,
+			 self_ref.release ());
   return 0;
 }