Implement namelist reading and early initialization of MPAS dynamical core

src/dynamics/mpas/Makefile.in.CESM

@@ -62,7 +62,7 @@ all:
 	@echo '    `make libmpas-clean ESM="CESM" LIBROOT="..."`'
 
 .PHONY: libmpas-prepare
-libmpas-prepare: libmpas-archiver-script.txt libmpas-no-physics libmpas-preview
+libmpas-prepare: libmpas-archiver-script.txt libmpas-no-physics libmpas-prefix-namelist-groups libmpas-preview
 
 # Combine multiple static libraries into `libmpas.a` via archiver/MRI script. This requires GNU or GNU-like archiver (`ar`) program.
 libmpas-archiver-script.txt:
@@ -79,6 +79,12 @@ libmpas-archiver-script.txt:
 libmpas-no-physics:
 	@sed -E -i -e "s/^ *PHYSICS=.+$$/PHYSICS=/g" core_atmosphere/Makefile
 
+# Prefix `mpas_` to MPAS namelist groups to avoid naming collisions.
+.PHONY: libmpas-prefix-namelist-groups
+libmpas-prefix-namelist-groups:
+	@sed -E -i -e "s/(^ *< *nml_record.+name=)\"(mpas_)?(\w+)\"/\1\"mpas_\3\"/g" core_atmosphere/Registry.xml
+	@sed -E -i -e "s/(^ *< *nml_record.+name=)\"(mpas_)?(\w+)\"/\1\"mpas_\3\"/g" core_atmosphere/diagnostics/Registry_*.xml
+
 .PHONY: libmpas-preview
 libmpas-preview:
 	@echo "Previewing build options for $(LIBROOT)/libmpas.a:"

src/dynamics/mpas/driver/dyn_mpas_subdriver.F90

@@ -41,10 +41,12 @@ end subroutine model_error_if
     type :: mpas_dynamical_core_type
         private
 
+        logical, public :: debug_output = .false.
+
         integer :: log_unit = output_unit
         integer :: mpi_comm = mpi_comm_null
         integer :: mpi_rank = 0
-        logical :: mpi_rank_master = .false.
+        logical :: mpi_rank_root = .false.
 
         ! Actual implementation is supplied at runtime.
         procedure(model_error_if), nopass, pointer :: model_error => null()
@@ -61,21 +63,25 @@ end subroutine model_error_if
     end type mpas_dynamical_core_type
 contains
     !> Print a debug message with optionally the value(s) of a variable.
-    !> If `printer` is not supplied, the MPI master rank will print. Otherwise, the designated MPI rank will print instead.
+    !> If `printer` is not supplied, the MPI root rank will print. Otherwise, the designated MPI rank will print instead.
     !> (KCW, 2024-02-03)
     subroutine dyn_mpas_debug_print(self, message, variable, printer)
         class(mpas_dynamical_core_type), intent(in) :: self
         character(*), intent(in) :: message
         class(*), optional, intent(in) :: variable(:)
         integer, optional, intent(in) :: printer
 
-#ifdef DEBUG
+        ! Bail out early if debug output is not requested.
+        if (.not. self % debug_output) then
+            return
+        end if
+
         if (present(printer)) then
             if (self % mpi_rank /= printer) then
                 return
             end if
         else
-            if (.not. self % mpi_rank_master) then
+            if (.not. self % mpi_rank_root) then
                 return
             end if
         end if
@@ -87,13 +93,13 @@ subroutine dyn_mpas_debug_print(self, message, variable, printer)
             write(self % log_unit, '(a)') 'dyn_mpas_debug_print (' // stringify([self % mpi_rank]) // '): ' // &
                 message
         end if
-#endif
     end subroutine dyn_mpas_debug_print
 
     !> Convert one or more values of any intrinsic data types to a character string for pretty printing.
     !> If `value` contains more than one element, the elements will be stringified, delimited by `separator`, then concatenated.
     !> If `value` contains exactly one element, the element will be stringified without using `separator`.
     !> If `value` contains zero element or is of unsupported data types, an empty character string is produced.
+    !> If `separator` is not supplied, it defaults to `, ` (i.e., a comma and a space).
     !> (KCW, 2024-02-04)
     pure function stringify(value, separator)
         use, intrinsic :: iso_fortran_env, only: int32, int64, real32, real64
@@ -226,7 +232,7 @@ subroutine dyn_mpas_init_phase1(self, mpi_comm, model_error_impl, log_unit, mpas
             call self % model_error('Invalid MPI communicator group', subname, __LINE__)
         end if
 
-        self % mpi_rank_master = (self % mpi_rank == 0)
+        self % mpi_rank_root = (self % mpi_rank == 0)
         self % log_unit = log_unit
 
         call self % debug_print(subname // ' entered')

src/dynamics/mpas/dyn_comp.F90

@@ -5,7 +5,7 @@ module dyn_comp
     use cam_abortutils, only: endrun
     use cam_control_mod, only: initial_run
     use cam_instance, only: atm_id
-    use cam_logfile, only: iulog
+    use cam_logfile, only: debug_output, debugout_none, iulog
     use runtime_obj, only: runtime_options
     use spmd_utils, only: mpicom
     use time_manager, only: get_start_date, get_stop_date, get_run_duration, timemgr_get_calendar_cf
@@ -55,10 +55,15 @@ subroutine dyn_readnl(namelist_path)
                    sec_since_midnight    ! Second(s) since midnight.
         type(iosystem_desc_t), pointer :: pio_iosystem => null()
 
+        ! Enable/disable the debug output of MPAS dynamical core according to the debug verbosity level of CAM-SIMA.
+        mpas_dynamical_core % debug_output = (debug_output > debugout_none)
+
         ! Get free units for MPAS so it can write its own log files, e.g., `log.atmosphere.0000.{out,err}`.
         log_unit(1) = shr_file_getunit()
         log_unit(2) = shr_file_getunit()
 
+        ! Initialize MPAS framework with supplied MPI communicator group and log units.
+        ! See comment blocks in `src/dynamics/mpas/driver/dyn_mpas_subdriver.F90` for details.
         call mpas_dynamical_core % init_phase1(mpicom, endrun, iulog, log_unit)
 
         cam_calendar = timemgr_get_calendar_cf()
@@ -72,11 +77,15 @@ subroutine dyn_readnl(namelist_path)
         call get_run_duration(run_duration(1), sec_since_midnight)
         run_duration(2:4) = sec_to_hour_min_sec(sec_since_midnight)
 
+        ! Read MPAS-related namelist variables from `namelist_path`, e.g., `atm_in`.
+        ! See comment blocks in `src/dynamics/mpas/driver/dyn_mpas_subdriver.F90` for details.
         call mpas_dynamical_core % read_namelist(namelist_path, &
             cam_calendar, start_date_time, stop_date_time, run_duration, initial_run)
 
         pio_iosystem => shr_pio_getiosys(atm_id)
 
+        ! Initialize MPAS framework with supplied PIO system descriptor.
+        ! See comment blocks in `src/dynamics/mpas/driver/dyn_mpas_subdriver.F90` for details.
         call mpas_dynamical_core % init_phase2(pio_iosystem)
 
         nullify(pio_iosystem)