DNA: support DNA type & name aliases

This allows us to rename struct & struct members in the source code
without changing the file format.

This is useful because the code becomes increasingly confusing when
names such as oops, ipo & dupli aren't used anywhere except DNA headers.

dna_rename_defs.h is used to define renaming operations.

The renaming it's self will be done separately.

1 files changed, 47 insertions, 0 deletions

diff --git a/source/blender/makesdna/intern/dna_rename_defs.h b/source/blender/makesdna/intern/dna_rename_defs.h
new file mode 100644
index 00000000000..cdf13e7103d
--- /dev/null
+++ b/source/blender/makesdna/intern/dna_rename_defs.h
@@ -0,0 +1,47 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * The Original Code is Copyright (C) 2001-2002 by NaN Holding BV.
+ * All rights reserved.
+ * DNA handling
+ */
+
+/** \file \ingroup DNA
+ *
+ * Defines in this header are only used to define blend file storage.
+ * This allows us to rename variables & structs without breaking compatibility.
+ *
+ * - When renaming the member of a struct which has it's self been renamed
+ *   refer to the newer name, not the original.
+ *
+ * - Changes here only change generated code for `makesdna.c` and `makesrna.c`
+ *   without impacting Blender's run-time, besides allowing us to use the new names.
+ *
+ * - Renaming something that has already been renamed can be done by editing the existing rename macro.
+ *   All references to the previous destination name can be removed since they're
+ *   never written to disk.
+ *
+ * \see versioning_dna.c for a actual version patching.
+ */
+
+/* No include guard (intentional). */
+
+/* Match RNA names where possible. */
+#if 0
+DNA_STRUCT_RENAME(Lamp, Light)
+DNA_STRUCT_RENAME(SpaceOops, SpaceOutliner)
+DNA_STRUCT_RENAME_ELEM(Camera, YF_dofdist, dof_distance)
+DNA_STRUCT_RENAME_ELEM(Object, dup_group, instance_collection)
+#endif