CAM-SE
Overview
This page documents the attempt to understand how CAM is compiled within the CIME framework.
First attempt
Compile a CAM-SE executable and examine the build log.
From examining the build log here, it appears that CAM is compiled as a static library file. Library files contain a set of subprograms that are compiled into a single binary library file.
Static libraries are bound to an executable before execution. Static libraries have the suffix “a” which denotes “archive.”
Dynamic libraries can be bound to an executable at runtime. Dynamic libraries have the suffix “so” which denotes “shared object.”
Build log from the first attempt
/glade/scratch/johnsonb/FHIST.cesm2_2_0.ne30_g17.002/bld/atm.bldlog.220611-170051.gz
Altering the gmake command for libatm.a to what it would be for a new case
(with case suffix .003) results in:
gmake complib -j 8 MODEL=cam COMPLIB=/glade/scratch/johnsonb/FHIST.cesm2_2_0.ne30_g17.003/bld/lib/libatm.a -f
/glade/work/johnsonb/cesm_runs/FHIST.cesm2_2_0.ne30_g17.003/Tools/Makefile
CIME_MODEL=cesm SMP=FALSE CASEROOT="/glade/work/johnsonb/cesm_runs/FHIST.cesm2_2_0.ne30_g17.003"
CASETOOLS="/glade/work/johnsonb/cesm_runs/FHIST.cesm2_2_0.ne30_g17.003/Tools"
CIMEROOT="/glade/work/johnsonb/cesm2_2_0/cime" COMP_INTERFACE="mct" COMPILER="intel"
DEBUG="FALSE" EXEROOT="/glade/scratch/johnsonb/FHIST.cesm2_2_0.ne30_g17.003/bld"
INCROOT="/glade/scratch/johnsonb/FHIST.cesm2_2_0.ne30_g17.003/bld/lib/include"
LIBROOT="/glade/scratch/johnsonb/FHIST.cesm2_2_0.ne30_g17.003/bld/lib"
MACH="cheyenne" MPILIB="mpt" NINST_VALUE="c1a1l1i1o1r1g1w1i1e1" OS="LINUX"
PIO_VERSION="1" SHAREDLIBROOT="/glade/scratch/johnsonb/FHIST.cesm2_2_0.ne30_g17.003/bld"
SMP_PRESENT="FALSE" USE_ESMF_LIB="FALSE" USE_MOAB="FALSE" CAM_CONFIG_OPTS="-physcam6"
COMP_LND="clm" COMPARE_TO_NUOPC="FALSE" CISM_USE_TRILINOS="FALSE" USE_TRILINOS="FALSE"
USE_ALBANY="FALSE" USE_PETSC="FALSE" USER_CPPDEFS=' -DPLON=1 -DPLAT=1 -DNUM_COMP_INST_ATM=1
-DNUM_COMP_INST_LND=1 -DNUM_COMP_INST_OCN=1 -DNUM_COMP_INST_ICE=1 -DNUM_COMP_INST_GLC=1
-DNUM_COMP_INST_ROF=1 -DNUM_COMP_INST_WAV=1 -DNUM_COMP_INST_IAC=1 -DNUM_COMP_INST_ESP=1
-DCAM -D_WK_GRAD -DNP=4 -DHAVE_F2003_PTR_BND_REMAP -D_MPI -DPLEV=32 -DPCNST=33
-DPCOLS=16 -DPSUBCOLS=1 -DN_RAD_CNST=30 -DPTRM=1 -DPTRN=1 -DPTRK=1 -DSPMD -DMODAL_AERO
-DMODAL_AERO_4MODE -DCLUBB_SGS -DCLUBB_CAM -DNO_LAPACK_ISNAN -DCLUBB_REAL_TYPE=dp'
When trying to run the gmake command for a case that is set up but not
built, $SOURCES and $BASENAMES aren’t set.
cd /glade/scratch/johnsonb/FHIST.cesm2_2_0.ne30_g17.002
grep -Rl SOURCES ./
[ ... ]
# Returns many things
grep -Rl BASENAMES ./
# Returns nothing...
Second attempt
This attempt will build a CESM case using ./case.build after editing the
Makefile to echo the values of environmental variables.
./create_newcase --case /glade/work/johnsonb/cesm_runs/FHIST.cesm2_2_0.ne30_g17.003 --compset FHIST --res ne30_g17 --mach cheyenne --project P86850054 --run-unsupported
What actually builds libatm.a?
cd /glade/work/johnsonb/cesm_runs/FHIST.cesm2_2_0.ne30_g17.003
grep -Rl libatm ./
./Tools/Makefile
I edited the Makefile to echo $(SOURCES), $(BASENAMES), $(OBJS), $(INCS):
801 #-------------------------------------------------------------------------
802 # Build & include dependency files
803 #-------------------------------------------------------------------------
[ ... ]
829
830 Filepath:
831 @echo "SOURCES=$(SOURCES)"
832 @echo "BASENAMES=$(BASENAMES)"
833 @echo "OBJS=$(OBJS)"
834 @echo "INCS=$(INCS)"
835 @echo "$(VPATH)" > $@
After making the above edits, build the case:
qcmd -q share -l select=1 -A $DARES_PROJECT -- ./case.build
[ ... ]
Building cesm from /glade/work/johnsonb/cesm2_2_0/cime/src/drivers/mct/cime_config/buildexe with output to /glade/scratch/johnsonb/FHIST.cesm2_2_0.ne30_g17.003/bld/cesm.bldlog.220707-143352
Time spent not building: 52.000454 sec
Time spent building: 1138.138125 sec
MODEL BUILD HAS FINISHED SUCCESSFULLY
Try to find where $(BASENAMES) was echoed:
cd /glade/scratch/johnsonb/FHIST.cesm2_2_0.ne30_g17.003
grep -Rl BASENAMES ./
# Still returns nothing ...
Resulting object and library files
All of the CAM object files are compiled here:
cd /glade/scratch/johnsonb/FHIST.cesm2_2_0.ne30_g17.003/bld/atm/obj
ls *dyn_grid*
dyn_grid.mod dyn_grid.o dyn_grid.optrpt
The actual library files are compiled here:
cd /glade/scratch/johnsonb/FHIST.cesm2_2_0.ne30_g17.003/bld/lib
ls
include libatm.a libesp.a libglc.a libiac.a libice.a libocn.a librof.a libwav.a
Note that libatm.a is a 53MB file.