From d81a8b509c8c734ceaf4aa44f120c80452c38706 Mon Sep 17 00:00:00 2001
From: Rahul Mahajan <aerorahul@users.noreply.github.com>
Date: Mon, 15 Aug 2022 16:49:10 -0400
Subject: [PATCH] use a robust Findwgrib2.cmake to find wgrib2 built w/ native
 wgrib2 build (#970)

---
 sorc/cmake/Findwgrib2.cmake     | 98 +++++++++++++++++++++++++++++++++
 sorc/reg2grb2.fd/CMakeLists.txt |  2 +-
 2 files changed, 99 insertions(+), 1 deletion(-)
 create mode 100644 sorc/cmake/Findwgrib2.cmake

diff --git a/sorc/cmake/Findwgrib2.cmake b/sorc/cmake/Findwgrib2.cmake
new file mode 100644
index 0000000000..ecede0d21f
--- /dev/null
+++ b/sorc/cmake/Findwgrib2.cmake
@@ -0,0 +1,98 @@
+# Find the wgrib2 headers, library and executable
+#
+# This module defines:
+#
+#   - wgrib2::wgrib2      - library and include directory, all in a single target.
+#   - WGRIB2_INCLUDE_DIR  - include directory
+#   - WGRIB2_LIBRARIES    - wgrib2 library
+#   - WGRIB2API_LIBRARIES - wgrib2_api library (if using NCEPLibs-wgrib2 cmake build system)
+#   - WGRIB2_EXE          - wgrib2 executable
+#
+# The following paths will be searched in order:
+#
+#   - WGRIB2_INCLUDE_DIRS - folders containing wgrib2.
+#   - WGRIB2_LIBRARY_DIRS - folders containing libwgrib2.a
+#   - wgrib2_ROOT         - root of wgrib2 installation
+#   - wgrib2_PATH         - root of wgrib2 installation
+#
+# TODO
+# Remove all instances of WGRIB2API_LIBRARIES when cmake build of wgrib2 is removed from all systems
+
+find_path(
+  WGRIB2_INCLUDE_DIR
+  NAMES wgrib2.h wgrib2api.mod
+  HINTS ${WGRIB2_INCLUDE_DIRS}
+        ${wgrib2_ROOT} $ENV{wgrib2_ROOT}
+        ${wgrib2_PATH} $ENV{wgrib2_PATH}
+  PATH_SUFFIXES include include/wgrib2
+  DOC "Path to wgrib2.h, wgrib2api.mod"
+  )
+
+find_library(
+  WGRIB2_LIBRARIES
+  NAMES libwgrib2.a
+  HINTS ${WGRIB2_LIBRARY_DIRS}
+        ${wgrib2_ROOT} $ENV{wgrib2_ROOT}
+        ${wgrib2_PATH} $ENV{wgrib2_PATH}
+  PATH_SUFFIXES lib lib64
+  DOC "Path to libwgrib2.a"
+  )
+
+find_library(
+  WGRIB2API_LIBRARIES
+  NAMES libwgrib2_api.a
+  HINTS ${WGRIB2_LIBRARY_DIRS}
+        ${wgrib2_ROOT} $ENV{wgrib2_ROOT}
+        ${wgrib2_PATH} $ENV{wgrib2_PATH}
+  PATH_SUFFIXES lib lib64
+  DOC "Path to libwgrib2_api.a"
+  )
+
+find_program(WGRIB2_EXE
+  NAMES wgrib2
+  HINTS ${wgrib2_ROOT} $ENV{wgrib2_ROOT}
+        ${wgrib2_PATH} $ENV{wgrib2_PATH}
+  PATH_SUFFIXES bin
+  DOC "Path to wgrib2 executable"
+  )
+
+mark_as_advanced(WGRIB2_INCLUDE_DIR WGRIB2_LIBRARIES WGRIB2API_LIBRARIES WGRIB2_EXE)
+
+message(DEBUG "[Findwgrib2.cmake]: creating target wgrib2::wgrib2")
+add_library(wgrib2::wgrib2 UNKNOWN IMPORTED)
+set_target_properties(wgrib2::wgrib2 PROPERTIES INTERFACE_INCLUDE_DIRECTORIES ${WGRIB2_INCLUDE_DIR})
+if(WGRIB2API_LIBRARIES)
+  message(DEBUG "[Findwgrib2.cmake]: linking with libwgrib2_api.a and libwgrib2.a")
+  set_target_properties(wgrib2::wgrib2 PROPERTIES IMPORTED_LOCATION ${WGRIB2API_LIBRARIES})
+  set_target_properties(wgrib2::wgrib2 PROPERTIES INTERFACE_LINK_LIBRARIES ${WGRIB2_LIBRARIES})
+else()
+  message(DEBUG "[Findwgrib2.cmake]: linking with libwgrib2.a")
+  set_target_properties(wgrib2::wgrib2 PROPERTIES IMPORTED_LOCATION ${WGRIB2_LIBRARIES})
+endif()
+
+# wgrib2 changed how it outputs --version from "v0.x.y.z" to "vx.y.z" starting in wgrib2 3.0
+execute_process(COMMAND ${WGRIB2_EXE} --version OUTPUT_VARIABLE version)
+if(version MATCHES "^v0.*")
+  string(SUBSTRING "${version}" 3 5 WGRIB2_VERSION)
+else()
+  string(SUBSTRING "${version}" 1 5 WGRIB2_VERSION)
+endif()
+unset(version)
+
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(wgrib2
+  REQUIRED_VARS WGRIB2_LIBRARIES WGRIB2_INCLUDE_DIR WGRIB2_EXE
+  VERSION_VAR WGRIB2_VERSION
+  )
+
+if(wgrib2_FOUND AND NOT wgrib2_FIND_QUIETLY)
+  message(STATUS "Findwgrib2:")
+  message(STATUS "  - WGRIB2_INCLUDE_DIR: ${WGRIB2_INCLUDE_DIR}")
+  message(STATUS "  - WGRIB2_LIBRARIES: ${WGRIB2_LIBRARIES}")
+  if(WGRIB2API_LIBRARIES)
+    message(STATUS "  - WGRIB2API_LIBRARIES: ${WGRIB2API_LIBRARIES}")
+  endif()
+  message(STATUS "  - WGRIB2_EXE: ${WGRIB2_EXE}")
+  message(STATUS "  - WGRIB2_VERSION: ${WGRIB2_VERSION}")
+endif()
+
diff --git a/sorc/reg2grb2.fd/CMakeLists.txt b/sorc/reg2grb2.fd/CMakeLists.txt
index 4157c315bf..c866ca515f 100644
--- a/sorc/reg2grb2.fd/CMakeLists.txt
+++ b/sorc/reg2grb2.fd/CMakeLists.txt
@@ -18,7 +18,7 @@ target_link_libraries(
   sp::sp_d
   bacio::bacio_4
   w3nco::w3nco_4
-  wgrib2::wgrib2_api
+  wgrib2::wgrib2
   NetCDF::NetCDF_Fortran)
 
 if(OpenMP_Fortran_FOUND)