creating ./docs folder while compiling docs

[theGreatWhiteShark]

As described in issue #630 the generation of the documentation using Doxygen via the build script ./build.sh d was not working. The problem was located in build/CMakeFiles/doc.dir/build.make line 58 where the CMakeFiles/doc target tries to enter the ./docs folder at the root directory of the repository. Since this folder is not created by either the build script or CMake the generation of the documentation fails.

To solve this issue I introduced a line in the ./CMakeList.txt file creating the missing ./docs/ folder.

[jeremyz]

Hi @theGreatWhiteShark !
I would create the directory in ${CMAKE_CURRENT_BINARY_DIR}/doc.
and to do so I would use :
add_custom_target(doc_dir ALL COMMAND ${CMAKE_COMMAND} -E make_directory ${CMAKE_CURRENT_BINARY_DIR}/doc)
then add DEPENDS doc_dir to the doc target.
so that the directory is always created at build time and not only at configure time.

[theGreatWhiteShark]

Ah, very nice.

I actually intended to implement it just like this. But since I'm not an expert in cmake I tried to add the -E make_directory option to the doc target itself and couldn't get it running.

Thanks!

[jeremyz]

cmake is a dirty bitch a would say (make_directory beeing deprecated for ages with no known alternative(that I know about)),
but as the guy who brought it to hydrogen, I should just shut my mouth ;)
I'll merge your patch and remove the then useless file(MAKE_DIRECTORY ...
and will alos change CMAKE_CURRENT_SOURCE_DIRto CMAKE_CURRENT_BINARY_DIR.

btw, I can't wait to find the time needed to review #627,
greetings to you @theGreatWhiteShark !