This short step-by-step tutorial should help you setup Code::Blocks IDE for use Intel's Fortran compiler on Linux. The Intel's Fortran version 2017 is used here. The setup process can be a bit different for other versions.
To start Code::Blocks, open a terminal in the folder with Code::Blocks. According to the Intel’s documentation, the environment variables should be set using provided script file “compilervars.sh”:
If you want to debug your code, compile your project with “ifort” compiler with option “-debug full”. Before the start of debugging make sure that the active debugger is GDB or “Target’s default” if you set correct debugger for “ifort” compiler: