FindNetCDF.cmake

#[==[
Provides the following variables:

  * `NetCDF_FOUND`: Whether NetCDF was found or not.
  * `NetCDF_INCLUDE_DIRS`: Include directories necessary to use NetCDF.
  * `NetCDF_LIBRARIES`: Libraries necessary to use NetCDF.
  * `NetCDF_VERSION`: The version of NetCDF found.
  * `NetCDF::NetCDF`: A target to use with `target_link_libraries`.
  * `NetCDF_HAS_PARALLEL`: Whether or not NetCDF was found with parallel IO support.
#]==]

function(FindNetCDF_get_is_parallel_aware include_dir)
  file(STRINGS "${include_dir}/netcdf_meta.h" _netcdf_lines
    REGEX "#define[ \t]+NC_HAS_PARALLEL[ \t]")
  string(REGEX REPLACE ".*NC_HAS_PARALLEL[ \t]*([0-1]+).*" "\\1" _netcdf_has_parallel "${_netcdf_lines}")
  if (_netcdf_has_parallel)
    set(NetCDF_HAS_PARALLEL TRUE PARENT_SCOPE)
  else()
    set(NetCDF_HAS_PARALLEL FALSE PARENT_SCOPE)
  endif()
endfunction()

# Try to find a CMake-built NetCDF.
find_package(netCDF CONFIG QUIET)
if (netCDF_FOUND)
  # Forward the variables in a consistent way.
  set(NetCDF_FOUND "${netCDF_FOUND}")
  set(NetCDF_INCLUDE_DIRS "${netCDF_INCLUDE_DIR}")
  set(NetCDF_LIBRARIES "${netCDF_LIBRARIES}")
  set(NetCDF_VERSION "${NetCDFVersion}")

  include(FindPackageHandleStandardArgs)
  find_package_handle_standard_args(NetCDF
    REQUIRED_VARS NetCDF_INCLUDE_DIRS NetCDF_LIBRARIES
    VERSION_VAR NetCDF_VERSION)

  if (NOT TARGET NetCDF::NetCDF)
    add_library(NetCDF::NetCDF INTERFACE IMPORTED)
    if (TARGET "netCDF::netcdf")
      # 4.7.3
      set_target_properties(NetCDF::NetCDF PROPERTIES
        INTERFACE_LINK_LIBRARIES "netCDF::netcdf")
    elseif (TARGET "netcdf")
      set_target_properties(NetCDF::NetCDF PROPERTIES
        INTERFACE_LINK_LIBRARIES "netcdf")
    else ()
      set_target_properties(NetCDF::NetCDF PROPERTIES
        INTERFACE_LINK_LIBRARIES "${netCDF_LIBRARIES}")
    endif ()
  endif ()

  FindNetCDF_get_is_parallel_aware("${NetCDF_INCLUDE_DIRS}")
  # Skip the rest of the logic in this file.
  return ()
endif ()

find_package(PkgConfig QUIET)
if (PkgConfig_FOUND)
  pkg_check_modules(_NetCDF QUIET netcdf IMPORTED_TARGET)
  if (_NetCDF_FOUND)
    # Forward the variables in a consistent way.
    set(NetCDF_FOUND "${_NetCDF_FOUND}")
    set(NetCDF_INCLUDE_DIRS "${_NetCDF_INCLUDE_DIRS}")
    set(NetCDF_LIBRARIES "${_NetCDF_LIBRARIES}")
    set(NetCDF_VERSION "${_NetCDF_VERSION}")

    include(FindPackageHandleStandardArgs)
    find_package_handle_standard_args(NetCDF
      REQUIRED_VARS NetCDF_LIBRARIES
      # This is not required because system-default include paths are not
      # reported by `FindPkgConfig`, so this might be empty. Assume that if we
      # have a library, the include directories are fine (if any) since
      # PkgConfig reported that the package was found.
      # NetCDF_INCLUDE_DIRS
      VERSION_VAR NetCDF_VERSION)

    if (NOT TARGET NetCDF::NetCDF)
      add_library(NetCDF::NetCDF INTERFACE IMPORTED)
      set_target_properties(NetCDF::NetCDF PROPERTIES
        INTERFACE_LINK_LIBRARIES "PkgConfig::_NetCDF")
    endif ()

    FindNetCDF_get_is_parallel_aware("${_NetCDF_INCLUDEDIR}")
    # Skip the rest of the logic in this file.
    return ()
  endif ()
endif ()

find_path(NetCDF_INCLUDE_DIR
  NAMES netcdf.h
  DOC "netcdf include directories")
mark_as_advanced(NetCDF_INCLUDE_DIR)

find_library(NetCDF_LIBRARY
  NAMES netcdf
  DOC "netcdf library")
mark_as_advanced(NetCDF_LIBRARY)

if (NetCDF_INCLUDE_DIR)
  file(STRINGS "${NetCDF_INCLUDE_DIR}/netcdf_meta.h" _netcdf_version_lines
    REGEX "#define[ \t]+NC_VERSION_(MAJOR|MINOR|PATCH|NOTE)")
  string(REGEX REPLACE ".*NC_VERSION_MAJOR *\([0-9]*\).*" "\\1" _netcdf_version_major "${_netcdf_version_lines}")
  string(REGEX REPLACE ".*NC_VERSION_MINOR *\([0-9]*\).*" "\\1" _netcdf_version_minor "${_netcdf_version_lines}")
  string(REGEX REPLACE ".*NC_VERSION_PATCH *\([0-9]*\).*" "\\1" _netcdf_version_patch "${_netcdf_version_lines}")
  string(REGEX REPLACE ".*NC_VERSION_NOTE *\"\([^\"]*\)\".*" "\\1" _netcdf_version_note "${_netcdf_version_lines}")
  set(NetCDF_VERSION "${_netcdf_version_major}.${_netcdf_version_minor}.${_netcdf_version_patch}${_netcdf_version_note}")
  unset(_netcdf_version_major)
  unset(_netcdf_version_minor)
  unset(_netcdf_version_patch)
  unset(_netcdf_version_note)
  unset(_netcdf_version_lines)

  FindNetCDF_get_is_parallel_aware("${NetCDF_INCLUDE_DIR}")
endif ()

include(FindPackageHandleStandardArgs)
find_package_handle_standard_args(NetCDF
  REQUIRED_VARS NetCDF_LIBRARY NetCDF_INCLUDE_DIR
  VERSION_VAR NetCDF_VERSION)

if (NetCDF_FOUND)
  set(NetCDF_INCLUDE_DIRS "${NetCDF_INCLUDE_DIR}")
  set(NetCDF_LIBRARIES "${NetCDF_LIBRARY}")

  if (NOT TARGET NetCDF::NetCDF)
    add_library(NetCDF::NetCDF UNKNOWN IMPORTED)
    set_target_properties(NetCDF::NetCDF PROPERTIES
      IMPORTED_LOCATION "${NetCDF_LIBRARY}"
      INTERFACE_INCLUDE_DIRECTORIES "${NetCDF_INCLUDE_DIR}")
  endif ()
endif ()