为NetCDF C ++创建CMake

问题描述

我正在尝试为使用NetCDF的项目创建CMake文件。我是CMake的新手（这是我的第一次尝试），因此对于其中的某些内容显而易见，我深表歉意。

要安装NetCDF，我按照here显示的git指南中的步骤进行操作

我相信我正确地执行了这些步骤。我正在尝试使用NetCDF C ++库，但出于编译目的，我还必须安装C库。我是这样使用的：

sudo apt install libnetcdf-dev

运行以下命令时，我会收到适当的输出（根据git指南）：

nc-config --has-nc4

到目前为止很好...我希望。这是我的CMakeLists.Txt：

cmake_minimum_required(VERSION 3.16)

project(orbit LANGUAGES CXX)

# ##############################################################################
# Conan Packages
# ##############################################################################

set(CONAN_EXTRA_REQUIRES "")  set(CONAN_EXTRA_OPTIONS "")

list(APPEND CONAN_EXTRA_REQUIRES boost/1.73.0) list(APPEND CONAN_EXTRA_REQUIRES eigen/3.3.7)

if(BUILD_SHARED_LIBS)   list(APPEND CONAN_EXTRA_OPTIONS "Pkg:shared=True") endif()

include(cmake/Conan.cmake) run_conan()

# ############################################################################## 
find_file(CMAKE_PREFIX_PATH netCDFCxxConfig.cmake) 
find_package (NetCDF required) include_directories(${NETCDF_INCLUDES})

# set(SOURCE test.cpp player.cpp player.hpp)

# include_directories(include)

# Search all .cpp files 
file(GLOB_RECURSE SOURCE_FILES "*.cpp")

add_executable(test ${SOURCE_FILES})

target_link_libraries(test 
                      PRIVATE
                          CONAN_PKG::boost
                          CONAN_PKG::eigen

                          ${NETCDF_LIBRARIES_CXX})

这是错误输出：

CMake Error at CMakeLists.txt:24 (find_package):
  By not providing "FindNetCDF.cmake" in CMAKE_MODULE_PATH this project has
  asked CMake to find a package configuration file provided by "NetCDF",but
  CMake did not find one.

  Could not find a package configuration file provided by "NetCDF" with any
  of the following names:

    NetCDFConfig.cmake
    netcdf-config.cmake

  Add the installation prefix of "NetCDF" to CMAKE_PREFIX_PATH or set
  "NetCDF_DIR" to a directory containing one of the above files.  If "NetCDF"
  provides a separate development package or SDK,be sure it has been
  installed.

我的理解是，此错误是由于我没有正确执行git指南中的以下内容而引起的：

请确保nc-config在您的PATH中，或netCDFConfig.cmake的位置在CMAKE_PREFIX_PATH中。

我尝试通过运行以下命令将nc-config添加到我的PATH：

export PATH="nc-config:$PATH"

但这不能解决问题...

此外，我尝试在计算机中找到一个netCDFConfig.cmake文件，但是该文件似乎不存在。我确实有一个netCDFCxxConfig.cmake，但不确定是否相同，或者在这里如何使用它。

有人对此问题有任何经验，并且知道如何解决吗？任何帮助将不胜感激，如果过去提供了这样的解决方案，我深表歉意。

编辑：

我能够让CMake最终找到该文件，但是现在丢失了寻找另一个文件...这是我在原始帖子中找不到的文件：

# NetCDF CXX Configuration Summary

####### Expanded from @PACKAGE_INIT@ by configure_package_config_file() #######
####### Any changes to this file will be overwritten by the next CMake run ####
####### The input file was netCDFCxxConfig.cmake.in                            ########

get_filename_component(PACKAGE_PREFIX_DIR "${CMAKE_CURRENT_LIST_DIR}/../../../" ABSOLUTE)

macro(set_and_check _var _file)
  set(${_var} "${_file}")
  if(NOT EXISTS "${_file}")
    message(FATAL_ERROR "File or directory ${_file} referenced by variable ${_var} does not exist !")
  endif()
endmacro()

macro(check_required_components _NAME)
  foreach(comp ${${_NAME}_FIND_COMPONENTS})
    if(NOT ${_NAME}_${comp}_FOUND)
      if(${_NAME}_FIND_required_${comp})
        set(${_NAME}_FOUND FALSE)
      endif()
    endif()
  endforeach()
endmacro()

####################################################################################

include(CMakeFindDependencyMacro)

if (1)
  if(EXISTS "")
    set(netCDF_ROOT "")
  endif()
  if(EXISTS "/usr/lib/x86_64-linux-gnu/cmake/netCDF")
    set(netCDF_DIR "/usr/lib/x86_64-linux-gnu/cmake/netCDF")
  endif()
  find_dependency(netCDF)
  set(NETCDF_C_LIBRARY ${netCDF_LIBRARIES})
  set(NETCDF_C_INCLUDE_DIR ${netCDF_INCLUDE_DIR})
else()
  set(NETCDF_C_LIBRARY "netcdf")
  set(NETCDF_C_INCLUDE_DIR "/usr/include")
endif()

if (NOT TARGET netCDF::netcdf)
  add_library(netCDF::netcdf UNKNowN IMPORTED)
  set_target_properties(netCDF::netcdf PROPERTIES
    IMPORTED_LOCATION "${NETCDF_C_LIBRARY}"
    INTERFACE_INCLUDE_DIRECTORIES "${NETCDF_C_INCLUDE_DIR}"
  )
endif()

include("${CMAKE_CURRENT_LIST_DIR}/netcdf-cxx4Targets.cmake")

最后一行是所有错误所在。在这里找到netcdf-cxx4Targets.cmake会遇到问题。

我刚发布的文件位于目录netcd-cxx4/build中 netcdf-cxx4Targets.cmake在目录中：

netcd-cxx4/build/CMakeFiles/Export/lib/cmake/netCDF

那么第一个应该能够找到另一个？

解决方法

您要使用netCDFCxxConfig.cmake文件。通过快速查看GitHub repository，可以找到该文件的模板（netCDFCxxConfig.cmake.in，但没有netCDFConfig.cmake.in的模板。因此，我的结论是维护人员可能在某个时候更改了配置文件名，而忘记将其自述文件更新为netCDFCxxConfig.cmake。

您可以将netCDFCxxConfig.cmake文件的位置添加到CMake文件中的CMAKE_PREFIX_PATH列表变量中。然后，链接到netCDFCxxConfig.cmake文件中定义的导入目标netCDF::netcdf。

...

# ############################################################################## 
# Don't do this.
find_file(CMAKE_PREFIX_PATH netCDFCxxConfig.cmake)
# Instead,append the path to the config file using the 'list' command.
list(APPEND CMAKE_PREFIX_PATH "/path/to/installed/netcdf")

# Look for the 'netCDFCxx' package,since that is what the config file is called.
find_package (netCDFCxx REQUIRED) 

# Probably don't need this if we use the imported target below.
include_directories(${NETCDF_INCLUDES})

# set(SOURCE test.cpp player.cpp player.hpp)

# include_directories(include)

# Search all .cpp files 
file(GLOB_RECURSE SOURCE_FILES "*.cpp")

add_executable(test ${SOURCE_FILES})

# Link to the imported target 'netCDF::netcdf' here instead.
target_link_libraries(test 
                      PRIVATE
                          CONAN_PKG::boost
                          CONAN_PKG::eigen
                          netCDF::netcdf)