1) Create directory
First create yourself a directory under your home(!) (so it gets backup up) in which you want to create the executable.
I usually call mine:
~/gem/v_5.1.1/Abs/...
For example:
mkdir -p ~/gem/v_5.1.1/Abs/My_Abs # Set 'My_Abs' to whatever you like. But make sure to give every executable directory a different 'my_Abs' name!
2) Populate directory
Go into the executable directory you just created above. For example:
cd ~/gem/v_5.1.1/Abs/My_Abs
a) Get the basename of abs-directory
Get the basename (last part of your directory path) of your abs-directory for later use:
base_dir=$( basename $(pwd) )
'base_dir' should now be set to 'My_Abs'. You can verify it with:
echo $base_dir
b) Clone the Git repository you want
For example:
git clone ~winger/gem/v_5.1.1/Abs/UQAM_development_FLake_CLASS/gem
then change into 'gem' directory that came with the clone:
cd gem
c) Create working directories
So the object files, libraries and executables will not be under your home, create links for the directories 'build' and 'work'. Pick a place under which you want to keep the object files, libraries and executables. Preferably under the default(!) space of you professors, for example:
work_space=~/projects/def-professor/${USER}/GEM_WORK_DIR # Set 'professor' to the CC name of your professor. You can find all of them under ~/projects.
Create the directories and the links (using ${base_dir} from above) :
mkdir -p ${work_space}/${base_dir}/build
mkdir -p ${work_space}/${base_dir}/work
ln -s ${work_space}/${base_dir}/build
ln -s ${work_space}/${base_dir}/work
3) Create the executables
a) Acquire compiler
(Only needed once per window/terminal.)
module add intel/2021.2.0 fftw-intel-2021
b) If you are not already in it, go into the 'gem' directory of your abs-directory:
cd ~/gem/v_5.1.1/Abs/My_Abs/gem
c) Set the variable 'abs_dir' to the name of your executable directory, including the 'gem' directory (needed under e))
abs_dir=$(pwd)
d) Change into 'build' directory:
cd build
e) Create make files and dependencies
(Only need once at the beginning and whenever you add any new routines or add include files or module "use" lines to an existing routine.)
cmake -DCOMPILER=intel -DCMAKE_VERBOSE_MAKEFILE=ON -DWORK_PREFIX=${abs_dir}/work ${abs_dir}/project
or add a flag to tell the compiler to compile P3 for GEM and not for WRF, although GEM should be the default:
cmake -DCMAKE_Fortran_FLAGS_INIT=-DECCCGEM -DCOMPILER=intel -DCMAKE_VERBOSE_MAKEFILE=ON -DWORK_PREFIX=${abs_dir}/work ${abs_dir}/project
f) Compile and create executable
make -j4 maingemdm
The key '-j4' makes the command use 4 cores in parallel. But you can also run it on one core only with:
make maingemdm
4) Modify source code
a) You can find the GEM routines under .../gem/src/*/*, for example :
Most dynamic routines are under:
.../gem/src/gemdyn/base
Most physics routines are under:
.../gem/src/rpnphy/base
Most surface routines are under:
.../gem/src/rpnphy/surface
b) Recreate the executable
Make sure you are in the 'build' directory!
Only if you add any new routines or add include files or module "use" lines to an existing routine you first need to recreate the dependencies and make files by re-executing the full cmake command under point 4d) again.
Otherwise it is enough to just re-execute:
make -j4 work
5) Use your executable
To use your own executable set 'GEM_ovbin' in your 'configexp.cfg' to the path of your executable directory, up until but excluding the 'gem' directory. For example:
GEM_ovbin=~/gem/v_5.1.1/Abs/my_abs