Implemented building with clang and transferred control on compilation flags back to CMake

[KOLANICH]

No description provided.

[technyon]

Thanks. Unfortunately I'm having troubles building with GCC (see below)

I checked out your branch and pulled my master into it. I'm using Arduino ESP core 2.0.4, my guess would be the changes don't play well with versions > 2.0.0. Building on a Ubuntu VM. Will look into it and see if I can fix it somehow, or maybe you have an idea.

--

-- Configuring done
CMake Error: Error required internal CMake variable not set, cmake may not be built correctly.
Missing variable is:
CMAKE_C_COMPILE_OBJECT
CMake Error: Error required internal CMake variable not set, cmake may not be built correctly.
Missing variable is:
CMAKE_C_COMPILE_OBJECT
CMake Error: Error required internal CMake variable not set, cmake may not be built correctly.
Missing variable is:
CMAKE_C_COMPILE_OBJECT
CMake Error: Error required internal CMake variable not set, cmake may not be built correctly.
Missing variable is:
CMAKE_C_COMPILE_OBJECT
-- Generating done
CMake Generate step failed. Build files cannot be regenerated correctly.

[KOLANICH]

It's a draft currently, it is not finished and my local version is a bit different, so if you make some patches upon this PR some effort will be needed to rebase everytning. BTW, I'm using Mega and Uno. Have not tried with ESP32 yet.

[technyon]

OK I see. Let me know when it's finished to I recheck. Might be worth upgrading to ESP32 it can do so much more :).