Rewrite registry.h

This rewrites registry.h, removing all the macros and replacing it
with relatively ordinary template classes.  The result is less code
than the previous setup.  It replaces large macros with a relatively
straightforward C++ class, and now manages its own cleanup.

The existing type-safe "key" class is replaced with the equivalent
template class.  This approach ended up requiring relatively few
changes to the users of the registry code in gdb -- code using the key
system just required a small change to the key's declaration.

All existing users of the old C-like API are now converted to use the
type-safe API.  This mostly involved changing explicit deletion
functions to be an operator() in a deleter class.

The old "save/free" two-phase process is removed, and replaced with a
single "free" phase.  No existing code used both phases.

The old "free" callbacks took a parameter for the enclosing container
object.  However, this wasn't truly needed and is removed here as
well.

1 files changed, 16 insertions, 21 deletions

diff --git a/gdb/python/py-objfile.c b/gdb/python/py-objfile.c
index 298f3f2..4cc5702 100644
--- a/gdb/python/py-objfile.c
+++ b/gdb/python/py-objfile.c
@@ -55,7 +55,20 @@ struct objfile_object
 extern PyTypeObject objfile_object_type
     CPYCHECKER_TYPE_OBJECT_FOR_TYPEDEF ("objfile_object");
 
-static const struct objfile_data *objfpy_objfile_data_key;
+/* Clear the OBJFILE pointer in an Objfile object and remove the
+   reference.  */
+struct objfpy_deleter
+{
+  void operator() (objfile_object *obj)
+  {
+    gdbpy_enter enter_py;
+    gdbpy_ref<objfile_object> object (obj);
+    object->objfile = nullptr;
+  }
+};
+
+static const registry<objfile>::key<objfile_object, objfpy_deleter>
+     objfpy_objfile_data_key;
 
 /* Require that OBJF be a valid objfile.  */
 #define OBJFPY_REQUIRE_VALID(obj)				\
@@ -668,16 +681,6 @@ gdbpy_lookup_objfile (PyObject *self, PyObject *args, PyObject *kw)
 
 
 
-/* Clear the OBJFILE pointer in an Objfile object and remove the
-   reference.  */
-static void
-py_free_objfile (struct objfile *objfile, void *datum)
-{
-  gdbpy_enter enter_py (objfile->arch ());
-  gdbpy_ref<objfile_object> object ((objfile_object *) datum);
-  object->objfile = NULL;
-}
-
 /* Return a new reference to the Python object of type Objfile
    representing OBJFILE.  If the object has already been created,
    return it.  Otherwise, create it.  Return NULL and set the Python
@@ -687,7 +690,7 @@ gdbpy_ref<>
 objfile_to_objfile_object (struct objfile *objfile)
 {
   PyObject *result
-    = ((PyObject *) objfile_data (objfile, objfpy_objfile_data_key));
+    = (PyObject *) objfpy_objfile_data_key.get (objfile);
   if (result == NULL)
     {
       gdbpy_ref<objfile_object> object
@@ -698,21 +701,13 @@ objfile_to_objfile_object (struct objfile *objfile)
 	return NULL;
 
       object->objfile = objfile;
-      set_objfile_data (objfile, objfpy_objfile_data_key, object.get ());
+      objfpy_objfile_data_key.set (objfile, object.get ());
       result = (PyObject *) object.release ();
     }
 
   return gdbpy_ref<>::new_reference (result);
 }
 
-void _initialize_py_objfile ();
-void
-_initialize_py_objfile ()
-{
-  objfpy_objfile_data_key
-    = register_objfile_data_with_cleanup (NULL, py_free_objfile);
-}
-
 int
 gdbpy_initialize_objfile (void)
 {