Question

这是我在StackOverflow上的第一篇文章，如果我的问题出现问题，请道歉。

我是CMake的新手，我在尝试使用库中使用的现有gtest目录在C ++项目中导入gtest（Google Test）时遇到了问题。

我的根CMakeLists.txt文件是这样的（我的更改是在“开始更改”和“结束更改”之间进行的）：

cmake_minimum_required(VERSION 2.6)

project(nifi-minifi-cpp)
set(PROJECT_NAME "nifi-minifi-cpp")
set(PROJECT_VERSION_MAJOR 0)
set(PROJECT_VERSION_MINOR 2)
set(PROJECT_VERSION_PATCH 0)

#### Establish Project Configuration ####
# Enable usage of the VERSION specifier
# https://cmake.org/cmake/help/v3.0/policy/CMP0048.html#policy:CMP0048
IF(POLICY CMP0048)
  CMAKE_POLICY(SET CMP0048 OLD)
ENDIF(POLICY CMP0048)

include(CheckCXXCompilerFlag)
CHECK_CXX_COMPILER_FLAG("-std=c++11" COMPILER_SUPPORTS_CXX11)
CHECK_CXX_COMPILER_FLAG("-std=c++0x" COMPILER_SUPPORTS_CXX0X)
if(COMPILER_SUPPORTS_CXX11)
    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11")
elseif(COMPILER_SUPPORTS_CXX0X)
    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++0x")
else()
        message(STATUS "The compiler ${CMAKE_CXX_COMPILER} has no C++11 support. Please use a different C++ compiler.")
endif()

set(CMAKE_CXX_STANDARD 11)
set(CMAKE_CXX_STANDARD_REQUIRED ON)

# Search for threads
find_package(Threads REQUIRED)

# Provide custom modules for the project
list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake")

add_subdirectory(thirdparty/yaml-cpp-yaml-cpp-0.5.3)
add_subdirectory(libminifi)
add_subdirectory(main)

# Generate source assembly
set(ASSEMBLY_BASE_NAME "${CMAKE_PROJECT_NAME}-${PROJECT_VERSION_MAJOR}.${PROJECT_VERSION_MINOR}.${PROJECT_VERSION_PATCH}")
set(CPACK_SOURCE_GENERATOR "TGZ")
set(CPACK_SOURCE_PACKAGE_FILE_NAME "${ASSEMBLY_BASE_NAME}-source")
set(CPACK_SOURCE_IGNORE_FILES "/build/;~$;${CPACK_SOURCE_IGNORE_FILES};${CMAKE_SOURCE_DIR}/.git/;${CMAKE_SOURCE_DIR}/.idea/;${CMAKE_SOURCE_DIR}/cmake-build-debug/")

# Generate binary assembly
install(FILES conf/minifi.properties conf/config.yml
        DESTINATION conf
        COMPONENT bin)

install(PROGRAMS bin/minifi.sh
        DESTINATION bin
        COMPONENT bin)

install(FILES LICENSE README.md NOTICE
        DESTINATION .
        COMPONENT bin)

set(CPACK_GENERATOR "TGZ")
set(CPACK_COMPONENT_INCLUDE_TOPLEVEL_DIRECTORY 1)
set(CPACK_PACKAGE_DESCRIPTION_SUMMARY "Apache NiFi MiNiFi C++ version ${VERSION}")
set(CPACK_PACKAGE_VENDOR "Apache NiFi")
set(CPACK_PACKAGE_DESCRIPTION_FILE "${CMAKE_CURRENT_SOURCE_DIR}/README.md")
set(CPACK_RESOURCE_FILE_LICENSE "${CMAKE_CURRENT_SOURCE_DIR}/LICENSE")
set(CPACK_PACKAGE_FILE_NAME "${ASSEMBLY_BASE_NAME}")
set(CPACK_BINARY_TGZ, "ON")

set(CPACK_ARCHIVE_COMPONENT_INSTALL ON)
set(CPACK_COMPONENTS_ALL bin)

include(CPack)

#### Begin changes
# Set up testing
enable_testing()
set(GTEST_ROOT "thirdparty/googletest/googletest")
add_subdirectory(thirdparty/googletest)
#
find_package(GTest REQUIRED)
include_directories(${GTEST_INCLUDE_DIRS})
add_executable(tailFileTest
        test/TailFileTest.cpp
        )
target_link_libraries(tailFileTest  ${GTEST_LIBRARY_DEBUG} ${GTEST_MAIN_LIBRARY_DEBUG})

add_test(
        NAME tailFileTest
        COMMAND tailFileTest
)


#add_dependencies(${PROJECT_TEST_NAME} googletest)

#set(PROJECT_TEST_NAME ${PROJECT_NAME}_test)
#file(GLOB TEST_SRC_FILES ${PROJECT_SOURCE_DIR}/test/*.cpp)
#
#add_executable(${PROJECT_TEST_NAME} ${TEST_SRC_FILES})
#add_dependencies(${PROJECT_TEST_NAME} googletest)
#### End changes

运行cmake ..时CMake输出（可能是更相关的错误消息）：

CMake Error at thirdparty/googletest/googletest/cmake/internal_utils.cmake:151 (add_library):
  add_library cannot create target "gtest" because another target with the
  same name already exists.  The existing target is a static library created
  in source directory
  "/home/dev/nifi-minifi-cpp/thirdparty/yaml-cpp-yaml-cpp-0.5.3/test/gmock-1.7.0/gtest".
  See documentation for policy CMP0002 for more details.

目前，我已经获得了googletest的副本：

/home/g/dev/nifi-minifi-cpp/thirdparty/googletest

现有的googletest目录位于：

/home/g/dev/nifi-minifi-cpp/thirdparty/yaml-cpp-yaml-cpp-0.5.3/test/gmock-1.7.0

以下是目录结构的快速图片：

.
├── CMakeLists.txt
├── test                             [<- My directory to store and run tests]
└── thirdparty
    ├── googletest                   [<- My googletest directory]
    └── yaml-cpp-yaml-cpp-0.5.3
        ├── test
        │   ├── CMakeLists.txt
        │   ├── gmock-1.7.0          [<- The existing googletest directory]

278 directories, 2096 files

总体目标是拥有一个test目录来运行测试。

对于我做错了什么，或者我应该做什么的任何建议或线索，将不胜感激。希望上面解释了我面临的挑战，如果有文件或错误消息，人们会认为我错过了这将有助于我将其粘贴在这里。

Answer 1

使用gtest这只是双重 3d-party 项目（在您的情况下为add_subdirectory）。第一个包含点是

add_subdirectory(gmock-1.7.0)

在yaml-cpp 子项目中，第二个包含点是

add_subdirectory(thirdparty/googletest)

在CMakeLists.txt。

这样的双重包含在CMake中不起作用，因此您需要消除add_subdirectory次呼叫之一。

在您的代码中，您可以通过add_subdirectory和ExternalProject_Add的组合替换execute_process方法。该方法将在配置阶段构建googletest（因此，find_package(GTest)将起作用），但不会使用googletest中的目标污染项目的命名空间。
在其他项目（yaml-cpp）中，您可以通过禁用测试来消除googletest。只需禁用适当的选项
```
option(YAML_CPP_BUILD_TOOLS "Enable testing and parse tools" OFF)
```
前
```
add_subdirectory(thirdparty/yaml-cpp-yaml-cpp-0.5.3)
```
（对于CMakeLists.txt禁用选项，您需要重新配置整个项目干净利落，即使用空的CMake缓存。）

注意，此选项还会禁用yaml-cpp项目的util/子目录下的某些实用程序。
与第一种方法类似，您可以将yaml-cpp子项目的包含更改为ExternalProject_Add + execute_process。这样一来，子项目的所有目标和目标都不会污染项目的命名空间。

与多个gtest

1 个答案: