CMake，GLFW：包括 X11，但未找到“XConvertSelection”

Question

Ubuntu 14.04、GLFW 3.2.1、OpenGL 4.5.0 NVIDIA 367.57

我正在尝试构建“Hello Triangle”OpenGL 示例，该示例位于 http://antongerdelan.net/opengl/hellotriangle.html 但我遇到了麻烦。我下载了 GLFW 源代码并在源代码外构建并安装时没有额外的标志或选项。

下面是 Hello Triangle 的 src/CMakeLists.txt 文件，该文件由 GLFW 和 SO 答案组合而成。在与链接顺序搏斗了一下之后，构建过程只给了我一个错误：

/usr/bin/ld: //usr/local/lib/libglfw3.a(x11_window.c.o): undefined reference to symbol 'XConvertSelection' /usr/lib/gcc/x86_64-linux-gnu/4.8/../../../x86_64-linux-gnu/libX11.so: error adding symbols: DSO missing from command line collect2: error: ld returned 1 exit status

XConvertSelection似乎来自X11，但我已经包含并链接到X11，如下图所示。如果 X11 已经包含和链接，为什么找不到这个项目？

=== src/CMakeLists.txt ===

# SOURCE CMAKELISTS

cmake_minimum_required( VERSION 2.6 )
project( HelloTriangle )

# ~ Special Libraries ~

# First you need to find the PkgConfig package. If this fails, you may need to install the pkg-config package for your distribution.
find_package(PkgConfig REQUIRED)

find_package(X11 REQUIRED)
if(NOT X11_FOUND)
    message("ERROR: x11 not found")
endif(NOT X11_FOUND)

# Note that the dependencies do not include OpenGL or GLU, as GLFW loads any OpenGL, OpenGL ES or Vulkan libraries it needs at runtime and does not use GLU. If your application calls OpenGL directly, instead of using a modern extension loader library you can find it by requiring the OpenGL package.
find_package(OpenGL REQUIRED)
if(NOT OPENGL_FOUND)
    message("ERROR: OpenGL not found")
endif(NOT OPENGL_FOUND)

# With just a few changes to your CMakeLists.txt, you can locate the package and target files generated when GLFW is installed.
find_package(glfw3 3.2 REQUIRED)

# This creates the CMake commands to find pkg-config packages. Then you need to find the GLFW package.
pkg_search_module(GLFW REQUIRED glfw3)

include_directories(${X11_INCLUDE_DIR})

# This creates the CMake variables you need to use GLFW. To be able to include the GLFW header, you need to tell your compiler where it is.
include_directories(${GLFW_INCLUDE_DIRS})

# After everything is included, add the executable so that we can link
add_executable( HelloTriangle hello_triangle.cpp )

target_link_libraries(HelloTriangle ${X11_LIBRARIES})

# Seems like a similar issue: http://stackoverflow.com/questions/14772681/c-compile-error-when-includeing-irrlicht-static-lib
target_link_libraries(HelloTriangle /usr/lib/x86_64-linux-gnu/libX11.so)
target_link_libraries(HelloTriangle /usr/lib/x86_64-linux-gnu/libXxf86vm.so.1)
# target_link_libraries(HelloTriangle /usr/lib/x86_64-linux-gnu/libXxf86vm.so)

# If OpenGL is found, the OPENGL_FOUND variable is true and the OPENGL_INCLUDE_DIR and OPENGL_gl_LIBRARY cache variables can be used.
target_include_directories(HelloTriangle PUBLIC ${OPENGL_INCLUDE_DIR})

target_link_libraries(HelloTriangle ${OPENGL_gl_LIBRARY})

target_link_libraries(HelloTriangle ${GL_LIBRARY})

# The OpenGL CMake package also looks for GLU. If GLU is found, the OPENGL_GLU_FOUND variable is true and the OPENGL_INCLUDE_DIR and OPENGL_glu_LIBRARY cache variables can be used.
target_link_libraries(HelloTriangle ${OPENGL_glu_LIBRARY})

# You also need to link against the correct libraries. If you are using the shared library version of GLFW, use the GLFW_LIBRARIES variable.
target_link_libraries(HelloTriangle ${GLFW_LIBRARIES}) # DYNAMIC: Does not find: XConvertSelection
# If you are using the static library version of GLFW, use the GLFW_STATIC_LIBRARIES variable instead.
# target_link_libraries(HelloTriangle ${GLFW_STATIC_LIBRARIES}) # STATIC: Does not find: glewExperimental , glewInit

Answer 1

在深入研究 SO 并与链接顺序搏斗几个小时后，我有以下几点：

=== src/CMakeLists.txt ===

# SOURCE CMAKELISTS

cmake_minimum_required( VERSION 2.6 )
project( HelloTriangle )

# ~ Special Libraries ~
find_package(PkgConfig REQUIRED) # First you need to find the PkgConfig package

find_package(X11 REQUIRED) # Make sure x is there 
if(NOT X11_FOUND)
    message("ERROR: x11 not found")
endif(NOT X11_FOUND)

find_package(OpenGL REQUIRED) # Make sure OpenGL is available for direct calls
if(NOT OPENGL_FOUND)
    message("ERROR: OpenGL not found")
endif(NOT OPENGL_FOUND)

find_package(glfw3 3.2 REQUIRED) # locate the package and target files generated when GLFW is installed.

pkg_search_module(GLFW REQUIRED glfw3) # CMake commands to find pkg-config packages

include_directories(${GLFW_INCLUDE_DIRS}) # creates the CMake variables you need to use GLFW.
include_directories(${X11_INCLUDE_DIR}) # Get all the x stuff

add_executable( HelloTriangle hello_triangle.cpp ) # After everything is included, add the executable 

target_include_directories(HelloTriangle PUBLIC ${OPENGL_INCLUDE_DIR}) # Obviously

target_link_libraries(HelloTriangle ${GLFW_LIBRARIES}) # If using the shared library, GLFW_LIBRARIES
# target_link_libraries(HelloTriangle ${GLFW_STATIC_LIBRARIES}) # If using the static library, GLFW_STATIC_LIBRARIES
target_link_libraries(HelloTriangle ${OPENGL_gl_LIBRARY}) # More OpenGL stuff I guess?
target_link_libraries(HelloTriangle ${GL_LIBRARY})
target_link_libraries(HelloTriangle ${OPENGL_glu_LIBRARY}) # The OpenGL CMake package also looks for GLU.
# http://stackoverflow.com/questions/23171894/cant-compile-easy-source-in-c-and-opengl-glfw-in-linux-in-netbeans
target_link_libraries(HelloTriangle GLEW m dl Xinerama Xrandr Xi Xcursor pthread) # GLFW misses this stuff!
# Seems like a similar issue: http://stackoverflow.com/questions/14772681/c-compile-error-when-includeing-irrlicht-static-lib
target_link_libraries(HelloTriangle /usr/lib/x86_64-linux-gnu/libX11.so) # x11 linking misses this stuff!
target_link_libraries(HelloTriangle /usr/lib/x86_64-linux-gnu/libXxf86vm.so.1)
target_link_libraries(HelloTriangle ${X11_LIBRARIES}) # x11 !

这种确切的设置在 Linux 系统上可能并不通用，但我认为它可能会帮助某人制定成功的链接顺序。