CMake: Create destination folder for doc_source.cpp generation

When compiling using 'MinGW Makefiles' the folders aren't created automatically.

Author: enetheru

cmake/python_callouts.cmake

@@ -112,6 +112,9 @@ function( generate_doc_source OUTPUT_PATH XML_SOURCES )
  list( TRANSFORM XML_SOURCES REPLACE "(.*\.xml)" "'\\1'" )
  list( JOIN XML_SOURCES "," XML_SOURCES )
 
+ get_filename_component(OUTPUT_DIR "${OUTPUT_PATH}" DIRECTORY)
+ file(MAKE_DIRECTORY ${OUTPUT_DIR} )
+
  # Python one-liner to run our command
  # lists in CMake are just strings delimited by ';', so this works.
  set( PYTHON_SCRIPT "from doc_source_generator import generate_doc_source"