Build: update CMake to support OpenImageIO 2.3.4

FindOpenImageIO was updated to link to separate OpenImageIO_Util for new
versions, where it is required. For older versions, we can not link to it
because there will be duplicated symbols.

Ref D14128

build_files/cmake/Modules/FindOpenImageIO.cmake

@@ -48,6 +48,8 @@ FIND_LIBRARY(OPENIMAGEIO_LIBRARY
     lib64 lib
   )
 
+set(_openimageio_LIBRARIES ${OPENIMAGEIO_LIBRARY})
+
 FIND_FILE(OPENIMAGEIO_IDIFF
   NAMES
     idiff
@@ -57,14 +59,47 @@ FIND_FILE(OPENIMAGEIO_IDIFF
     bin
 )
 
+# Additionally find util library if needed. In old versions this library was
+# included in libOpenImageIO and linking to both would duplicate symbols. In
+# new versions we need to link to both.
+FIND_FILE(_openimageio_export
+  NAMES
+    export.h
+  PATHS
+    ${OPENIMAGEIO_INCLUDE_DIR}/OpenImageIO
+  NO_DEFAULT_PATH
+)
+
+# Use existence of OIIO_UTIL_API to check if it's a separate lib.
+FILE(STRINGS "${_openimageio_export}" _openimageio_util_define
+     REGEX "^[ \t]*#[ \t]*define[ \t]+OIIO_UTIL_API.*$")
+
+IF(_openimageio_util_define)
+  FIND_LIBRARY(OPENIMAGEIO_UTIL_LIBRARY
+    NAMES
+      OpenImageIO_Util
+    HINTS
+      ${_openimageio_SEARCH_DIRS}
+    PATH_SUFFIXES
+      lib64 lib
+    )
+
+  LIST(APPEND _openimageio_LIBRARIES ${OPENIMAGEIO_UTIL_LIBRARY})
+ENDIF()
+
+# In cmake version 3.21 and up, we can instead use the NO_CACHE option for
+# FIND_FILE so we don't need to clear it from the cache here.
+UNSET(_openimageio_export CACHE)
+UNSET(_openimageio_util_define)
+
 # handle the QUIETLY and REQUIRED arguments and set OPENIMAGEIO_FOUND to TRUE if
 # all listed variables are TRUE
 INCLUDE(FindPackageHandleStandardArgs)
 FIND_PACKAGE_HANDLE_STANDARD_ARGS(OpenImageIO DEFAULT_MSG
-    OPENIMAGEIO_LIBRARY OPENIMAGEIO_INCLUDE_DIR)
+    _openimageio_LIBRARIES OPENIMAGEIO_INCLUDE_DIR)
 
 IF(OPENIMAGEIO_FOUND)
-  SET(OPENIMAGEIO_LIBRARIES ${OPENIMAGEIO_LIBRARY})
+  SET(OPENIMAGEIO_LIBRARIES ${_openimageio_LIBRARIES})
   SET(OPENIMAGEIO_INCLUDE_DIRS ${OPENIMAGEIO_INCLUDE_DIR})
   IF(EXISTS ${OPENIMAGEIO_INCLUDE_DIR}/OpenImageIO/pugixml.hpp)
     SET(OPENIMAGEIO_PUGIXML_FOUND TRUE)
@@ -78,7 +113,9 @@ ENDIF()
 MARK_AS_ADVANCED(
   OPENIMAGEIO_INCLUDE_DIR
   OPENIMAGEIO_LIBRARY
+  OPENIMAGEIO_UTIL_LIBRARY
   OPENIMAGEIO_IDIFF
 )
 
 UNSET(_openimageio_SEARCH_DIRS)
+UNSET(_openimageio_LIBRARIES)