[gdb/python] Use py_{none,notimplemented} more often

Replace:
...
    {
      Py_INCREF (Py_NotImplemented);
      return Py_NotImplemented;
    }
...
with:
...
    return py_notimplemented ().release ();
...

Likewise for py_none.

Approved-By: Tom Tromey <tom@tromey.com>

gdb/python/py-block.c

@@ -550,10 +550,7 @@ blpy_richcompare (PyObject *self, PyObject *other, int op)
 {
   if (!PyObject_TypeCheck (other, &block_object_type)
       || (op != Py_EQ && op != Py_NE))
-    {
-      Py_INCREF (Py_NotImplemented);
-      return Py_NotImplemented;
-    }
+    return py_notimplemented ().release ();
 
   bool expected = self == other;
   bool equal = op == Py_EQ;

gdb/python/py-connection.c

@@ -321,8 +321,7 @@ struct py_send_packet_callbacks : public send_remote_packet_callbacks
     else
       {
 	/* We didn't get back any result data; set the result to None.  */
-	Py_INCREF (Py_None);
-	m_result.reset (Py_None);
+	m_result = py_none ();
       }
   }
 

gdb/python/py-finishbreakpoint.c

@@ -127,10 +127,7 @@ bpfinishpy_pre_stop_hook (struct gdbpy_breakpoint_object *bp_obj)
 	      gdbpy_print_stack ();
 	}
       else
-	{
-	  Py_INCREF (Py_None);
-	  self_finishbp->return_value = Py_None;
-	}
+	self_finishbp->return_value = py_none ().release ();
     }
   catch (const gdb_exception &except)
     {

gdb/python/py-frame.c

@@ -153,8 +153,7 @@ frapy_name (PyObject *self, PyObject *args)
     }
   else
     {
-      result = Py_None;
-      Py_INCREF (Py_None);
+      result = py_none ().release ();
     }
 
   return result;
@@ -724,10 +723,7 @@ frapy_richcompare (PyObject *self, PyObject *other, int op)
 
   if (!PyObject_TypeCheck (other, &frame_object_type)
       || (op != Py_EQ && op != Py_NE))
-    {
-      Py_INCREF (Py_NotImplemented);
-      return Py_NotImplemented;
-    }
+    return py_notimplemented ().release ();
 
   frame_object *self_frame = (frame_object *) self;
   frame_object *other_frame = (frame_object *) other;

gdb/python/py-lazy-string.c

@@ -72,10 +72,7 @@ stpy_get_encoding (PyObject *self, void *closure)
   if (self_string->encoding)
     result = PyUnicode_FromString (self_string->encoding);
   else
-    {
-      result = Py_None;
-      Py_INCREF (result);
-    }
+    result = py_none ().release ();
 
   return result;
 }

gdb/python/py-record-btrace.c

@@ -621,10 +621,7 @@ btpy_list_richcompare (PyObject *self, PyObject *other, int op)
   const btpy_list_object * const obj2 = (btpy_list_object *) other;
 
   if (Py_TYPE (self) != Py_TYPE (other))
-    {
-      Py_INCREF (Py_NotImplemented);
-      return Py_NotImplemented;
-    }
+    return py_notimplemented ().release ();
 
   switch (op)
   {
@@ -652,8 +649,7 @@ btpy_list_richcompare (PyObject *self, PyObject *other, int op)
       break;
   }
 
-  Py_INCREF (Py_NotImplemented);
-  return Py_NotImplemented;
+  return py_notimplemented ().release ();
 }
 
 /* Implementation of

gdb/python/py-record.c

@@ -416,10 +416,7 @@ recpy_element_richcompare (PyObject *self, PyObject *other, int op)
   const recpy_element_object * const obj2 = (recpy_element_object *) other;
 
   if (Py_TYPE (self) != Py_TYPE (other))
-    {
-      Py_INCREF (Py_NotImplemented);
-      return Py_NotImplemented;
-    }
+    return py_notimplemented ().release ();
 
   switch (op)
   {
@@ -443,8 +440,7 @@ recpy_element_richcompare (PyObject *self, PyObject *other, int op)
       break;
   }
 
-  Py_INCREF (Py_NotImplemented);
-  return Py_NotImplemented;
+  return py_notimplemented ().release ();
 }
 
 /* Create a new gdb.RecordGap object.  */

gdb/python/py-symbol.c

@@ -68,10 +68,7 @@ sympy_get_type (PyObject *self, void *closure)
   SYMPY_REQUIRE_VALID (self, symbol);
 
   if (symbol->type () == NULL)
-    {
-      Py_INCREF (Py_None);
-      return Py_None;
-    }
+    return py_none ().release ();
 
   return type_to_type_object (symbol->type ()).release ();
 }

gdb/python/py-type.c

@@ -1118,10 +1118,7 @@ typy_richcompare (PyObject *self, PyObject *other, int op)
   /* We can only compare ourselves to another Type object, and only
      for equality or inequality.  */
   if (type2 == NULL || (op != Py_EQ && op != Py_NE))
-    {
-      Py_INCREF (Py_NotImplemented);
-      return Py_NotImplemented;
-    }
+    return py_notimplemented ().release ();
 
   if (type1 == type2)
     result = true;

gdb/python/py-value.c

@@ -416,8 +416,7 @@ valpy_get_address (PyObject *self, void *closure)
 	}
       catch (const gdb_exception &except)
 	{
-	  val_obj->address = Py_None;
-	  Py_INCREF (Py_None);
+	  val_obj->address = py_none ().release ();
 	}
     }