METIS/ParMETIS build updated. Ticket NOAA-EMC#1309

Older versions of ParMETIS have METIS and GKLIB included
with the source code. Static link libraries libmetis.a
contains GKLib object files. CMake configuration was
updated to only link against GKLIB is the library is
found in METIS_PATH.

Changes
-------
 [x] FindGKLIB.cmake is optional with METIS depentencies for
     target linker library being added when found.

cmake/FindGKLIB.cmake

@@ -7,12 +7,13 @@ set_target_properties(GKLIB::GKLIB PROPERTIES
   IMPORTED_LOCATION "${gklib_lib}"
   INTERFACE_INCLUDE_DIRECTORIES "${gklib_inc}")
 
-## Finalize find_package
 include(FindPackageHandleStandardArgs)
 
-find_package_handle_standard_args(
-    ${CMAKE_FIND_PACKAGE_NAME}
-    REQUIRED_VARS gklib_lib
-    gklib_inc)
-
-message(STATUS "Found GKLIB: ${gklib_lib}")
+if(gklib_inc MATCHES "NOTFOUND" OR gklib_lib MATCHES "NOTFOUND")
+  set(${CMAKE_FIND_PACKAGE_NAME}_FOUND False)
+else()
+  find_package_handle_standard_args(
+      ${CMAKE_FIND_PACKAGE_NAME}
+      REQUIRED_VARS gklib_lib
+      gklib_inc)
+endif()

cmake/FindMETIS.cmake

@@ -1,15 +1,19 @@
 find_library(metis_lib NAMES libmetis.a libmetis.so libmetis.dylib HINTS ENV METIS_PATH PATH_SUFFIXES lib)
 find_path(metis_inc metis.h HINTS ENV METIS_PATH PATH_SUFFIXES include)
 
-find_package(GKLIB REQUIRED)
-
 add_library(METIS::METIS STATIC IMPORTED)
 
 set_target_properties(METIS::METIS PROPERTIES
   IMPORTED_LOCATION "${metis_lib}"
   INTERFACE_INCLUDE_DIRECTORIES "${metis_inc}")
 
-target_link_libraries(METIS::METIS INTERFACE GKLIB::GKLIB)
+find_package(GKLIB)
+if(NOT GKLIB_FOUND)
+  message(STATUS "GKLIB not found")
+  target_link_libraries(METIS::METIS)
+else()
+  target_link_libraries(METIS::METIS INTERFACE GKLIB::GKLIB)
+endif()
 
 ## Finalize find_package
 include(FindPackageHandleStandardArgs)
@@ -18,5 +22,3 @@ find_package_handle_standard_args(
     ${CMAKE_FIND_PACKAGE_NAME}
     REQUIRED_VARS metis_lib
     metis_inc)
-
-message(STATUS "Found METIS: ${metis_lib}")

cmake/FindParMETIS.cmake

@@ -18,5 +18,3 @@ find_package_handle_standard_args(
     ${CMAKE_FIND_PACKAGE_NAME}
     REQUIRED_VARS parmetis_lib
                   parmetis_inc)
-
-message(STATUS "Found ParMETIS: ${parmetis_lib}")