c++ - 由于体系结构 x86_64 的 undefined symbol ，GLFW 的最小示例失败

Question

我正在尝试为 GLFW 编译以下最小示例:

#include <GLFW/glfw3.h>
#include <thread>

int main() {
    glfwInit();
    std::this_thread::sleep_for(std::chrono::seconds(1));
    glfwTerminate();
    return 0;
}

我的 CMakeLists.txt 文件是:

cmake_minimum_required(VERSION 3.9)
project(viewer)

set(CMAKE_CXX_STANDARD 11)

find_package(glfw3 3.2 REQUIRED)
include_directories(${GLFW_INCLUDE_DIRS})

add_executable(viewer main.cpp)

target_link_libraries(viewer ${GLFW_LIBRARIES})

如果我尝试编译代码，它会失败并显示以下错误消息:

[ 50%] Linking CXX executable visualiser
Undefined symbols for architecture x86_64:
  "_glfwInit", referenced from:
      _main in main.cpp.o
  "_glfwTerminate", referenced from:
      _main in main.cpp.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make[3]: *** [visualiser] Error 1
make[2]: *** [CMakeFiles/visualiser.dir/all] Error 2
make[1]: *** [CMakeFiles/visualiser.dir/rule] Error 2
make: *** [visualiser] Error 2

我看到类似的问题，例如:

• Trouble compiling GLFW, undefined symbols
• http://dudandan.com/2017/02/15/Setup-glfw-and-glew/

但他们的解决方案并没有真正帮助。

更新:根据@thomas_f 的评论，我修改了我的CMakeLists.txt 文件如下:

cmake_minimum_required(VERSION 3.9)
project(viewer)

set(CMAKE_CXX_STANDARD 11)

find_package(glfw3 3.2 REQUIRED)
include_directories(${GLFW3_INCLUDE_DIR})

add_executable(viewer main.cpp)

target_link_libraries(viewer ${GLFW3_LIBRARY})
message(GLFW LIB: ${GLFW3_LIBRARY})

我还确保在我的构建目录中没有 CMakeCache.txt:

$ ls -a
.                 ..                .idea             CMakeLists.txt    cmake-build-debug main.cpp

但是，我仍然收到相同的错误消息。看来，

/Applications/CLion.app/Contents/bin/cmake/bin/cmake -DCMAKE_BUILD_TYPE=Debug -G "CodeBlocks - Unix Makefiles" ........./viewer
GLFWLIB:
-- Configuring done
-- Generating done
-- Build files have been written to: /Users/denis/Documents/projects/theia/code/visualiser/cmake-build-debug

[Finished]

所以看起来 ${GLFW3_LIBRARY} 没有定义。

Answer 1

来自 glfw3Config.cmake :

# - Config file for the glfw3 package
# It defines the following variables
#   GLFW3_INCLUDE_DIR, the path where GLFW headers are located
#   GLFW3_LIBRARY_DIR, folder in which the GLFW library is located
#   GLFW3_LIBRARY, library to link against to use GLFW

您似乎引用了错误的变量。此外，无需调用 include_directories()在这种情况下，由于 GLFW 显然安装在标准位置，即您的编译器已经知道在哪里可以找到它。

编辑:我能够重现链接器错误并将变量名称更改为 GLFW3_LIBRARY修复它。

澄清:将您的链接命令更改为:target_link_libraries(viewer ${GLFW3_LIBRARY})

如果您使用的是 Mac OS，请更新:如果您遇到与 OP 相同的问题，可能是因为 glfw3Config.cmake 不导出我的回答中提到的变量。相反，它创建了一个导入的库，glfw .在这种情况下，链接到 glfw 的正确方法就是简单地这样做:target_link_libraries(<target> glfw) .

如果glfw使用 brew 安装, 你应该找到 .cmake -文件位于:/usr/local/Cellar/glfw/<version>/lib/cmake/glfw3 .