使用CMake ExternalProject_Add構建mongo-cxx-driver

Question

我正在嘗試在基於CMake的項目中構建mongo-cxx-driver 。 該項目應該在Windows，macOS和ubuntu容器中構建，我想確保我在所有這些平台上的軟件都將使用相同的驅動程序版本，因此我無法負擔通過apt-get ， brew等安裝驅動程序及其依賴項因此，我只有一個選擇： ExternalProject_Add 。 但是鑒於libmongoc的設置方式，我很難進行這項工作。 以下是我目前擁有的CMake模塊。

include(ExternalProject)

set(libmongoc_CMAKE_ARGS
    "-DCMAKE_BUILD_TYPE:STRIING=${CMAKE_BUILD_TYPE}"
    "-DENABLE_TESTS:BOOL=OFF"
    "-DENABLE_STATIC:BOOL=OFF"
    "-DENABLE_EXAMPLES:BOOL=OFF"
    "-DENABLE_EXTRA_ALIGNMENT:BOOL=OFF"
)

set(mongocxx_CMAKE_ARGS
    "-DCMAKE_CXX_COMPILER=${CMAKE_CXX_COMPILER}"
    "-DCMAKE_BUILD_TYPE:STRIING=${CMAKE_BUILD_TYPE}"
    "-DBUILD_SHARED_LIBS:BOOL=ON"
    "-DENABLE_TESTS:BOOL=OFF"
    "-DENABLE_EXAMPLES:BOOL=OFF"
    "-DBSONCXX_POLY_USE_BOOST:BOOL=ON"
    "-DBSONCXX_POLY_USE_MNMLSTC:BOOL=OFF"
    "-Dlibbson-1.0_DIR:PATH=${OTS_DEPDENDENCIES_DIR}/libmongoc/src/libbson"
)

if (NOT TARGET libmongoc)
    ExternalProject_Add(
        libmongoc
        GIT_REPOSITORY  "https://github.com/mongodb/mongo-c-driver.git"
        GIT_TAG         "1.12.0"
        SOURCE_DIR      "${OTS_DEPDENDENCIES_DIR}/libmongoc"
        BINARY_DIR      "${OTS_DEPDENDENCIES_DIR}/libmongoc"
        CMAKE_ARGS      "${libmongoc_CMAKE_ARGS}"
        INSTALL_COMMAND ""
    )
endif()

if (NOT TARGET mongocxx)
    ExternalProject_Add(
        mongocxx
        GIT_REPOSITORY  "https://github.com/mongodb/mongo-cxx-driver.git"
        GIT_TAG         "r3.3.1"
        SOURCE_DIR      "${OTS_DEPDENDENCIES_DIR}/mongocxx"
        BINARY_DIR      "${OTS_DEPDENDENCIES_DIR}/mongocxx"
        CMAKE_ARGS      "${mongocxx_CMAKE_ARGS}"
        INSTALL_COMMAND ""
        DEPENDS         libmongoc
    )
endif()

注意CMAKE選項libbson-1.0_DIR作為mongo-cxx-driver的CMAKE_ARGS提供。 我對此表示懷疑，我相信可能是罪魁禍首。 有了它，我得到以下錯誤：

CMake Error at ${OTS_DEPENDENCIES_DIR}/libmongoc/src/libbson/libbson-1.0-config.cmake:30 (message):
    File or directory
    ${OTS_DEPENDENCIES_DIR}/include/libbson-1.0
    referenced by variable BSON_INCLUDE_DIRS does not exist !
Call Stack (most recent call first):
    ${OTS_DEPENDENCIES_DIR}/libmongoc/src/libbson/libbson-1.0-config.cmake:46 (set_and_check)
    src/bsoncxx/CMakeLists.txt:81 (find_package)

哪種方式有意義，因為src/bsoncxx/CMakeLists.txt:81讀取：

get_filename_component(PACKAGE_PREFIX_DIR "${CMAKE_CURRENT_LIST_DIR}/../../../" ABSOLUTE)
set_and_check (BSON_INCLUDE_DIRS "${PACKAGE_PREFIX_DIR}/include/libbson-1.0")

這使得CMake最終在不存在的${OTS_DEPDENDENCIES_DIR}/include中尋找libbson-1.0。 如果可以的話，我可以告訴cmake，“嘿，不要運行這個find_package ”，我可以給你自己的INCLUDE_DIR ， LIBRARIES和DEFINITIONS路徑。

如果刪除此選項，則會出現以下錯誤：

CMake Error at src/bsoncxx/CMakeLists.txt:81 (find_package):
By not providing "Findlibbson-1.0.cmake" in CMAKE_MODULE_PATH this project
has asked CMake to find a package configuration file provided by
"libbson-1.0", but CMake did not find one.

Could not find a package configuration file provided by "libbson-1.0"
(requested version 1.10.0) with any of the following names:

libbson-1.0Config.cmake
libbson-1.0-config.cmake

Add the installation prefix of "libbson-1.0" to CMAKE_PREFIX_PATH or set
"libbson-1.0_DIR" to a directory containing one of the above files.  If
"libbson-1.0" provides a separate development package or SDK, be sure it
has been installed.

這也不是很奇怪，因為CMake嘗試find_package libbson-1.0，但無法確定它的安裝位置。

Answer 1

初步評論

在查看詳細信息時，以下是一些初步評論：

• 對SOURCE_DIR和BINARY_DIR使用不同的目錄
• 代替CMAKE_ARG ，更喜歡CMAKE_CACHE_ARGS
• libbson-1.0_DIR不應設置為源目錄，而應設置為包含config-file包的構建目錄（以下鏈接提供了有關此概念的更多詳細信息）
• 確保始終指定CMake參數的類型（ -DCMAKE_CXX_COMPILER:PATH=${CMAKE_CXX_COMPILER}而不是-DCMAKE_CXX_COMPILER=${CMAKE_CXX_COMPILER} ）
• 不要為多配置生成器設置CMAKE_BUILD_TYPE

關於最后一點，這意味着您應該執行以下操作：

set(EXTERNAL_PROJECT_OPTIONAL_CMAKE_CACHE_ARGS)
if(NOT DEFINED CMAKE_CONFIGURATION_TYPES)
  list(APPEND EXTERNAL_PROJECT_OPTIONAL_CMAKE_CACHE_ARGS
    -DCMAKE_BUILD_TYPE:STRING=${CMAKE_BUILD_TYPE}
    )
endif()

在本文中，您將學習如何構建項目： 在cmake項目中使用第三方庫的正確方法

允許編譯mongocxx“ test.cpp”的工作項目

以下是CMakeLists.txt和test.cpp的內容， test.cpp允許構建名為<build-dir>/Test-build/test_mongocxx的可執行文件：

• 的CMakeLists.txt：

   cmake_minimum_required(VERSION 3.12) set(CMAKE_CXX_STANDARD 11) project(Test) option(${PROJECT_NAME}_SUPERBUILD "Build ${PROJECT_NAME} and the projects it depends on." ON) if(${PROJECT_NAME}_SUPERBUILD) include(ExternalProject) set(common_cmake_cache_args -DCMAKE_CXX_COMPILER:PATH=${CMAKE_CXX_COMPILER} ) if(NOT DEFINED CMAKE_CONFIGURATION_TYPES) list(APPEND common_cmake_cache_args -DCMAKE_BUILD_TYPE:STRING=${CMAKE_BUILD_TYPE} ) endif() ExternalProject_Add(libmongoc GIT_REPOSITORY "https://github.com/mongodb/mongo-c-driver.git" GIT_TAG "1.12.0" GIT_PROGRESS 1 GIT_SHALLOW 1 SOURCE_DIR "${CMAKE_BINARY_DIR}/libmongoc" BINARY_DIR "${CMAKE_BINARY_DIR}/libmongoc-build" INSTALL_DIR "${CMAKE_BINARY_DIR}/libmongoc-install" CMAKE_CACHE_ARGS ${common_cmake_cache_args} -DCMAKE_INSTALL_PREFIX:PATH=${CMAKE_BINARY_DIR}/libmongoc-install -DENABLE_TESTS:BOOL=OFF -DENABLE_STATIC:BOOL=OFF -DENABLE_EXAMPLES:BOOL=OFF -DENABLE_EXTRA_ALIGNMENT:BOOL=OFF #INSTALL_COMMAND "" ) set(libmongoc-1.0_DIR "${CMAKE_BINARY_DIR}/libmongoc-install/lib/cmake/libmongoc-1.0/") set(libbson-1.0_DIR "${CMAKE_BINARY_DIR}/libmongoc-install/lib/cmake/libbson-1.0/") ExternalProject_Add(libmongocxx GIT_REPOSITORY "https://github.com/mongodb/mongo-cxx-driver.git" GIT_TAG "r3.3.1" GIT_PROGRESS 1 GIT_SHALLOW 1 SOURCE_DIR "${CMAKE_BINARY_DIR}/libmongocxx" BINARY_DIR "${CMAKE_BINARY_DIR}/libmongocxx-build" INSTALL_DIR "${CMAKE_BINARY_DIR}/libmongocxx-install" CMAKE_CACHE_ARGS ${common_cmake_cache_args} -DCMAKE_INSTALL_PREFIX:PATH=${CMAKE_BINARY_DIR}/libmongocxx-install -DBUILD_SHARED_LIBS:BOOL=ON -DENABLE_TESTS:BOOL=OFF -DENABLE_EXAMPLES:BOOL=OFF -DBSONCXX_POLY_USE_BOOST:BOOL=OFF -DBSONCXX_POLY_USE_MNMLSTC:BOOL=ON -DBSONCXX_POLY_USE_STD:BOOL=OFF -Dlibmongoc-1.0_DIR:PATH=${libmongoc-1.0_DIR} -Dlibbson-1.0_DIR:PATH=${libbson-1.0_DIR} DEPENDS libmongoc ) set(libmongocxx_DIR "${CMAKE_BINARY_DIR}/libmongocxx-install/lib/cmake/libmongocxx-3.3.1/") set(libbsoncxx_DIR "${CMAKE_BINARY_DIR}/libmongocxx-install//lib/cmake/libbsoncxx-3.3.1/") function(ExternalProject_AlwaysConfigure proj) # This custom external project step forces the configure and later # steps to run. _ep_get_step_stampfile(${proj} "configure" stampfile) ExternalProject_Add_Step(${proj} forceconfigure COMMAND ${CMAKE_COMMAND} -E remove ${stampfile} COMMENT "Forcing configure step for '${proj}'" DEPENDEES build ALWAYS 1 ) endfunction() ExternalProject_Add(${PROJECT_NAME} SOURCE_DIR "${CMAKE_SOURCE_DIR}" BINARY_DIR "${CMAKE_BINARY_DIR}/${PROJECT_NAME}-build" DOWNLOAD_COMMAND "" UPDATE_COMMAND "" CMAKE_CACHE_ARGS ${common_cmake_cache_args} -D${PROJECT_NAME}_SUPERBUILD:BOOL=OFF -Dlibbsoncxx_DIR:PATH=${libbsoncxx_DIR} -Dlibmongocxx_DIR:PATH=${libmongocxx_DIR} INSTALL_COMMAND "" DEPENDS libmongocxx ) ExternalProject_AlwaysConfigure(${PROJECT_NAME}) return() endif() message(STATUS "Configuring inner-build") find_package(libmongocxx REQUIRED) add_executable(test_mongocxx test.cpp) target_link_libraries(test_mongocxx PUBLIC ${LIBMONGOCXX_LIBRARIES}) target_include_directories(test_mongocxx PUBLIC ${LIBMONGOCXX_INCLUDE_DIRS}) target_compile_definitions(test_mongocxx PUBLIC ${LIBMONGOCXX_DEFINITIONS}) 

• test.cpp（從https://mongodb.github.io/mongo-cxx-driver/mongocxx-v3/installation/#step-6-test-your-installation復制）：

   #include <iostream> #include <bsoncxx/builder/stream/document.hpp> #include <bsoncxx/json.hpp> #include <mongocxx/client.hpp> #include <mongocxx/instance.hpp> int main(int, char**) { mongocxx::instance inst{}; mongocxx::client conn{mongocxx::uri{}}; bsoncxx::builder::stream::document document{}; auto collection = conn["testdb"]["testcollection"]; document << "hello" << "world"; collection.insert_one(document.view()); auto cursor = collection.find({}); for (auto&& doc : cursor) { std::cout << bsoncxx::to_json(doc) << std::endl; } }