IO: Move Abstract Hierarchy Iterator into `io/common`

The goal of the `AbstractHierarchyIterator` class (and supporting
classes) was to use it in different exporters. It shouldn't be part of
the USD module + namespace any more, now that it will also be used in
the upcoming Alembic exporter rewrite.

The source files are moved into `io/common`, which is compiled & linked
into a new library `bf_io_common`. The unittests are still inside the
`tests/gtests/usd` directory. They should be moved to a separate test
module too, but that will be delayed until after T73268 has been
resolved.

Reviewed By: mont29

Differential Revision: https://developer.blender.org/D7669

1 files changed, 45 insertions, 0 deletions

diff --git a/source/blender/io/common/CMakeLists.txt b/source/blender/io/common/CMakeLists.txt
new file mode 100644
index 00000000000..4ed6f12762e
--- /dev/null
+++ b/source/blender/io/common/CMakeLists.txt
@@ -0,0 +1,45 @@
+# ***** BEGIN GPL LICENSE BLOCK *****
+#
+# 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) 2020, Blender Foundation
+# All rights reserved.
+# ***** END GPL LICENSE BLOCK *****
+
+set(INC
+  .
+  ../../blenkernel
+  ../../blenlib
+  ../../depsgraph
+  ../../makesdna
+)
+
+set(INC_SYS
+)
+
+set(SRC
+  intern/abstract_hierarchy_iterator.cc
+
+  IO_abstract_hierarchy_iterator.h
+)
+
+set(LIB
+  bf_blenkernel
+  bf_blenlib
+)
+
+blender_add_lib(bf_io_common "${SRC}" "${INC}" "${INC_SYS}" "${LIB}")
+
+target_link_libraries(bf_io_common INTERFACE)