[RFA 4/4] Change Python code to use new_reference

[Tom Tromey <tom@tromey.com>]

This changes a few spots in the Python code to use new_reference
rather than the manual incref+constructor that was previously being
done.

2018-04-29  Tom Tromey  <tom@tromey.com>

	* varobj.c (varobj_set_visualizer): Use new_reference.
	* python/python.c (gdbpy_decode_line): Use new_reference.
	* python/py-cmd.c (cmdpy_function, cmdpy_completer_helper): Use
	new_reference.
---
 gdb/ChangeLog       |  7 +++++++
 gdb/python/py-cmd.c |  7 +++----
 gdb/python/python.c | 10 ++--------
 gdb/varobj.c        |  5 ++---
 4 files changed, 14 insertions(+), 15 deletions(-)

diff --git a/gdb/python/py-cmd.c b/gdb/python/py-cmd.c
index bff445f62f..27c4689413 100644
--- a/gdb/python/py-cmd.c
+++ b/gdb/python/py-cmd.c
@@ -138,8 +138,8 @@ cmdpy_function (struct cmd_list_element *command,
       error (_("Could not convert arguments to Python string."));
     }
 
-  gdbpy_ref<> ttyobj (from_tty ? Py_True : Py_False);
-  Py_INCREF (ttyobj.get ());
+  gdbpy_ref<> ttyobj
+    = gdbpy_ref<>::new_reference (from_tty ? Py_True : Py_False);
   gdbpy_ref<> result (PyObject_CallMethodObjArgs ((PyObject *) obj, invoke_cst,
 						  argobj.get (), ttyobj.get (),
 						  NULL));
@@ -246,8 +246,7 @@ cmdpy_completer_helper (struct cmd_list_element *command,
   if (word == NULL)
     {
       /* "brkchars" phase.  */
-      wordobj.reset (Py_None);
-      Py_INCREF (Py_None);
+      wordobj = gdbpy_ref<>::new_reference (Py_None);
     }
   else
     {
diff --git a/gdb/python/python.c b/gdb/python/python.c
index 9eae8a1aef..0dd7d6a6ad 100644
--- a/gdb/python/python.c
+++ b/gdb/python/python.c
@@ -876,10 +876,7 @@ gdbpy_decode_line (PyObject *self, PyObject *args)
 	}
     }
   else
-    {
-      result.reset (Py_None);
-      Py_INCREF (Py_None);
-    }
+    result = gdbpy_ref<>::new_reference (Py_None);
 
   gdbpy_ref<> return_result (PyTuple_New (2));
   if (return_result == NULL)
@@ -892,10 +889,7 @@ gdbpy_decode_line (PyObject *self, PyObject *args)
 	return NULL;
     }
   else
-    {
-      unparsed.reset (Py_None);
-      Py_INCREF (Py_None);
-    }
+    unparsed = gdbpy_ref<>::new_reference (Py_None);
 
   PyTuple_SetItem (return_result.get (), 0, unparsed.release ());
   PyTuple_SetItem (return_result.get (), 1, result.release ());
diff --git a/gdb/varobj.c b/gdb/varobj.c
index 4656bfa6b9..a0df485ae9 100644
--- a/gdb/varobj.c
+++ b/gdb/varobj.c
@@ -1455,9 +1455,8 @@ varobj_set_visualizer (struct varobj *var, const char *visualizer)
   gdbpy_enter_varobj enter_py (var);
 
   mainmod = PyImport_AddModule ("__main__");
-  gdbpy_ref<> globals (PyModule_GetDict (mainmod));
-  Py_INCREF (globals.get ());
-
+  gdbpy_ref<> globals
+    = gdbpy_ref<>::new_reference (PyModule_GetDict (mainmod));
   gdbpy_ref<> constructor (PyRun_String (visualizer, Py_eval_input,
 					 globals.get (), globals.get ()));
 
-- 
2.13.6