Updating CMake build to support checking for dependencies, independent build

CMakeLists.txt

@@ -1,3 +1,28 @@
+# This is the main CMake build file for fv3atm.
+
+cmake_minimum_required(VERSION 3.15)
+
+# Get the version from the VERSION file.
+file(STRINGS "VERSION" pVersion)
+
+project(
+  fv3atm
+  VERSION ${pVersion}
+  LANGUAGES C Fortran)
+list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake")
+
+# Find external packages.
+find_package(NetCDF 4.3.3 REQUIRED C Fortran)
+find_package(MPI REQUIRED C Fortran)
+find_package(ESMF 8.0.0 REQUIRED)
+
+# Find NCEPLIBS packages.
+find_package(w3nco 2.4.0 REQUIRED)
+find_package(w3emc 2.7.3 REQUIRED)
+find_package(bacio 2.4.0 REQUIRED)
+find_package(sigio 2.3.2 REQUIRED)
+find_package(nemsio 2.5.0 REQUIRED)
+find_package(sp 2.3.3 REQUIRED)
 
 ###############################################################################
 ### CCPP

VERSION

@@ -0,0 +1 @@
+2.0.0

cmake/FindESMF.cmake

@@ -0,0 +1,130 @@
+# - Try to find ESMF
+#
+# Requires setting ESMFMKFILE to the filepath of esmf.mk. If this is NOT set,
+# then ESMF_FOUND will always be FALSE. If ESMFMKFILE exists, then ESMF_FOUND=TRUE
+# and all ESMF makefile variables will be set in the global scope. Optionally,
+# set ESMF_MKGLOBALS to a string list to filter makefile variables. For example,
+# to globally scope only ESMF_LIBSDIR and ESMF_APPSDIR variables, use this CMake
+# command in CMakeLists.txt:
+#
+#   set(ESMF_MKGLOBALS "LIBSDIR" "APPSDIR")
+
+
+# Add the ESMFMKFILE path to the cache if defined as system env variable
+if (DEFINED ENV{ESMFMKFILE} AND NOT DEFINED ESMFMKFILE)
+  set(ESMFMKFILE $ENV{ESMFMKFILE} CACHE FILEPATH "Path to ESMF mk file")
+endif ()
+
+# Found the mk file and ESMF exists on the system
+if (EXISTS ${ESMFMKFILE})
+  set(ESMF_FOUND TRUE CACHE BOOL "ESMF mk file found" FORCE)
+  # Did not find the ESMF mk file
+else()
+  set(ESMF_FOUND FALSE CACHE BOOL "ESMF mk file NOT found" FORCE)
+  # Best to warn users that without the mk file there is no way to find ESMF
+  if (NOT DEFINED ESMFMKFILE)
+    message(FATAL_ERROR "ESMFMKFILE not defined. This is the path to esmf.mk file. \
+Without this filepath, ESMF_FOUND will always be FALSE.")
+  endif ()
+endif()
+
+# Only parse the mk file if it is found
+if (ESMF_FOUND)
+  # Read the mk file
+  file(STRINGS "${ESMFMKFILE}" esmfmkfile_contents)
+  # Parse each line in the mk file
+  foreach(str ${esmfmkfile_contents})
+    # Only consider uncommented lines
+    string(REGEX MATCH "^[^#]" def ${str})
+    # Line is not commented
+    if (def)
+      # Extract the variable name
+      string(REGEX MATCH "^[^=]+" esmf_varname ${str})
+      # Extract the variable's value
+      string(REGEX MATCH "=.+$" esmf_vardef ${str})
+      # Only for variables with a defined value
+      if (esmf_vardef)
+        # Get rid of the assignment string
+        string(SUBSTRING ${esmf_vardef} 1 -1 esmf_vardef)
+        # Remove whitespace
+        string(STRIP ${esmf_vardef} esmf_vardef)
+        # A string or single-valued list
+        if(NOT DEFINED ESMF_MKGLOBALS)
+          # Set in global scope
+          set(${esmf_varname} ${esmf_vardef})
+          # Don't display by default in GUI
+          mark_as_advanced(esmf_varname)
+        else() # Need to filter global promotion
+          foreach(m ${ESMF_MKGLOBALS})
+            string(FIND ${esmf_varname} ${m} match)
+            # Found the string
+            if(NOT ${match} EQUAL -1)
+              # Promote to global scope
+              set(${esmf_varname} ${esmf_vardef})
+              # Don't display by default in the GUI
+              mark_as_advanced (esmf_varname)
+              # No need to search for the current string filter
+              break()
+            endif()
+          endforeach()
+        endif()
+      endif()
+    endif()
+  endforeach()
+
+  # Construct ESMF_VERSION from ESMF_VERSION_STRING_GIT
+  if(ESMF_FOUND)
+    # ESMF_VERSION_MAJOR and ESMF_VERSION_MINOR are defined in ESMFMKFILE
+    set(ESMF_VERSION 0)
+    set(ESMF_VERSION_PATCH ${ESMF_VERSION_REVISION})
+    set(ESMF_BETA_RELEASE FALSE)
+    if(ESMF_VERSION_BETASNAPSHOT MATCHES "^('T')$")
+      set(ESMF_BETA_RELEASE TRUE)
+      string(REGEX REPLACE ".*beta_snapshot_*\([0-9]*\).*" "\\1" ESMF_BETA_SNAPSHOT "${ESMF_VERSION_STRING_GIT}")
+    endif()
+    set(ESMF_VERSION "${ESMF_VERSION_MAJOR}.${ESMF_VERSION_MINOR}.${ESMF_VERSION_PATCH}")
+  endif()
+
+  separate_arguments(ESMF_F90COMPILEPATHS NATIVE_COMMAND ${ESMF_F90COMPILEPATHS})
+  foreach (ITEM ${ESMF_F90COMPILEPATHS})
+     string(REGEX REPLACE "^-I" "" ITEM "${ITEM}")
+     list(APPEND tmp ${ITEM})
+  endforeach()
+  set(ESMF_F90COMPILEPATHS ${tmp})
+
+  add_library(esmf UNKNOWN IMPORTED)
+  # Look for static library, if not found try dynamic library
+  find_library(esmf_lib NAMES libesmf.a PATHS ${ESMF_LIBSDIR})
+  if(esmf_lib MATCHES "esmf_lib-NOTFOUND")
+    message(STATUS "Static ESMF library not found, searching for dynamic library instead")
+    find_library(esmf_lib NAMES esmf_fullylinked PATHS ${ESMF_LIBSDIR})
+    if(esmf_lib MATCHES "esmf_lib-NOTFOUND")
+      message(FATAL_ERROR "Neither the dynamic nor the static ESMF library was found")
+    endif()
+    set(ESMF_INTERFACE_LINK_LIBRARIES "")
+  else()
+    # When linking the static library, also need the ESMF linker flags; strip any leading/trailing whitespaces
+    string(STRIP "${ESMF_F90ESMFLINKRPATHS} ${ESMF_F90ESMFLINKPATHS} ${ESMF_F90LINKPATHS} ${ESMF_F90LINKLIBS} ${ESMF_F90LINKOPTS}" ESMF_INTERFACE_LINK_LIBRARIES)
+  endif()
+
+  message(STATUS "Found ESMF library: ${esmf_lib}")
+  if(ESMF_BETA_RELEASE)
+    message(STATUS "Detected ESMF Beta snapshot ${ESMF_BETA_SNAPSHOT}")
+  endif()
+
+  set_target_properties(esmf PROPERTIES
+    IMPORTED_LOCATION ${esmf_lib}
+    INTERFACE_INCLUDE_DIRECTORIES "${ESMF_F90COMPILEPATHS}"
+    INTERFACE_LINK_LIBRARIES "${ESMF_INTERFACE_LINK_LIBRARIES}")
+
+endif()
+
+## Finalize find_package
+include(FindPackageHandleStandardArgs)
+
+find_package_handle_standard_args( ${CMAKE_FIND_PACKAGE_NAME}
+    REQUIRED_VARS ESMF_LIBSDIR
+                  ESMF_INTERFACE_LINK_LIBRARIES
+                  ESMF_F90COMPILEPATHS
+    VERSION_VAR ESMF_VERSION
+    HANDLE_COMPONENTS )