CMakeLists: add cmake target to build Doxygen docs

adding cmake target to build Doxygen documentations. Doxygen docs are built together with the application by default if Doxygen is installed in the system, and can be disabled by disabling BUILD_DOC option. The resulting html pages are generated in the build/html directory.

Signed-off-by: Francesco Pham francesco.pham@huawei.com

CMakeLists.txt

@@ -6,4 +6,24 @@ enable_testing()
 set(VERSION_MAJOR 0)
 set(VERSION_MINOR 1)
 
-add_subdirectory(linux)
+add_subdirectory(linux)
\ No newline at end of file
+
+# indicating the documentation build as an option and set it to ON by default
+option(BUILD_DOC "Build documentation" ON)
+
+# check if Doxygen is installed
+find_package(Doxygen)
+if (DOXYGEN_FOUND AND BUILD_DOC)
+  set(DOXYFILE ${CMAKE_CURRENT_SOURCE_DIR}/docs/Doxyfile)
+
+  message("Doxygen build started")
+
+  # the option ALL which allows to build the docs together with the application
+  add_custom_target( doc_doxygen ALL
+          COMMAND ${DOXYGEN_EXECUTABLE} ${DOXYFILE}
+          WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}
+          COMMENT "Generating API documentation with Doxygen"
+          VERBATIM )
+elseif (BUILD_DOC)
+  message("If you want API documentation to be generated, Doxygen needs to be installed.")
+endif (DOXYGEN_FOUND AND BUILD_DOC)