构建 GLEW 程序时未定义引用？

Question

我设置了简单的 OpenGl 项目（Clion IDE，msys 的 g++ 编译器） 我下载了glfw和glew源文件，用mingw32-make手动编译它们。 由于链接问题仍然无法构建项目（我猜）。同时，我以前用过这种方式 glfw 没有任何问题，只有添加 glew 库才开始出现问题。 我是 c++ 新手，所以这个错误让我很困惑。我已经没有办法修复它了。

cmake：

cmake_minimum_required(VERSION 3.14)
project(udemy1)

set(CMAKE_CXX_STANDARD 17)
add_executable(udemy1
        src/main.cpp
        )

add_library(glew STATIC IMPORTED)
add_library(glfw STATIC IMPORTED)

set_target_properties(glew PROPERTIES
        IMPORTED_LOCATION "${CMAKE_CURRENT_SOURCE_DIR}/Dependencies/GLEW/libglew32.a"
        INTERFACE_INCLUDE_DIRECTORIES "${CMAKE_CURRENT_SOURCE_DIR}/include")
set_target_properties(glfw PROPERTIES
        IMPORTED_LOCATION "${CMAKE_CURRENT_SOURCE_DIR}/Dependencies/GLFW/libglfw3.a"
        INTERFACE_INCLUDE_DIRECTORIES "${CMAKE_CURRENT_SOURCE_DIR}/include")

target_link_libraries(udemy1 glew)
target_link_libraries(udemy1 glfw)

源

#include <stdio.h>

#include <GL/glew.h>
#include <GLFW/glfw3.h>

const GLint WIDTH = 800, HEIGHT = 600;//window dimensions

int main()
{
    if (!glfwInit())
    {
        printf("GLFW init failed!");
        glfwTerminate();
        return 1;
    }

    //setup GLFW window props
    //OpenGL version
    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR,3);
    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR,3);
    //CORE FILE -> no backwards compatibility
    glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
    //allow forward compat
    glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE);

    GLFWwindow *mainWindow = glfwCreateWindow(WIDTH, HEIGHT, "test window", NULL, NULL);
    if(!mainWindow)
    {
        printf("GLFW window creation failed");
        glfwTerminate();
        return 1;
    }

    //get buffer size information
    int bufferWidth, bufferHeight;
    glfwGetFramebufferSize(mainWindow, &bufferWidth, &bufferHeight);

    //set context for glew to use
    glfwMakeContextCurrent(mainWindow);

    //allow modern extentions
    glewExperimental = GL_TRUE;

    if(glewInit() != GLEW_OK)
    {
        printf("glew init failed!");
        glfwDestroyWindow(mainWindow);
        glfwTerminate();
        return 1;
    }

    //set up viewport size
    glViewport(0, 0, bufferWidth, bufferHeight);

    //loop untill window closed
    while(!glfwWindowShouldClose(mainWindow))
    {
        //get and handle user input events
        glfwPollEvents();//check for events
        //clear window
        glClearColor(1.0f, 0.0f, 0.0f, 1.0f);
        glClear(GL_COLOR_BUFFER_BIT);

        glfwSwapBuffers(mainWindow);//two scenes
    }
    return 0;
}

project structure:
udemy1
    -build
    -cmake-build-debug
    -Dependencies
        -GLEW
            -glew32.dll
            -glewinfo.exe
            -libglew32.a
            -libglew32.dll.a
            -visualinfo.exe
        -GLFW
            -glfw3.dll
            -libglfw3.a
            -libglfw3dll.a
    -include
        -GL
            -glew.h
            -glxew.h
            -wglew.h
        -GLFW
            -glfw3.h
            -glfw3native.h
    -src
        -main.cpp
    CmakeList.txt

编辑，附加错误。我的错

====================[ Build | all | Debug ]=====================================
"D:\DEV\cpp\cl\CLion 2019.2\bin\cmake\win\bin\cmake.exe" --build D:\DEV\cpp\projects\udemy1\build --target all -- -j 8
mingw32-make[1]: Entering directory 'D:/DEV/cpp/projects/udemy1/build'
mingw32-make[2]: Entering directory 'D:/DEV/cpp/projects/udemy1/build'
mingw32-make[2]: Leaving directory 'D:/DEV/cpp/projects/udemy1/build'
mingw32-make[2]: Entering directory 'D:/DEV/cpp/projects/udemy1/build'
[ 50%] Linking CXX executable udemy1.exe
C:/msys64/ucrt64/bin/../lib/gcc/x86_64-w64-mingw32/13.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: CMakeFiles\udemy1.dir/objects.a(main.cpp.obj): in function `main':
D:/DEV/cpp/projects/udemy1/src/main.cpp:42:(.text+0xe9): undefined reference to `__imp_glewExperimental'
C:/msys64/ucrt64/bin/../lib/gcc/x86_64-w64-mingw32/13.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: D:/DEV/cpp/projects/udemy1/src/main.cpp:44:(.text+0xf3): undefined reference to `__imp_glewInit'
C:/msys64/ucrt64/bin/../lib/gcc/x86_64-w64-mingw32/13.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: D:/DEV/cpp/projects/udemy1/src/main.cpp:53:(.text+0x140): undefined reference to `glViewport'
C:/msys64/ucrt64/bin/../lib/gcc/x86_64-w64-mingw32/13.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: D:/DEV/cpp/projects/udemy1/src/main.cpp:61:(.text+0x166): undefined reference to `glClearColor'
C:/msys64/ucrt64/bin/../lib/gcc/x86_64-w64-mingw32/13.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: D:/DEV/cpp/projects/udemy1/src/main.cpp:62:(.text+0x170): undefined reference to `glClear'
collect2.exe: error: ld returned 1 exit status
mingw32-make[2]: *** [CMakeFiles\udemy1.dir\build.make:88: udemy1.exe] Error 1
mingw32-make[2]: Leaving directory 'D:/DEV/cpp/projects/udemy1/build'
mingw32-make[1]: *** [CMakeFiles\Makefile2:72: CMakeFiles/udemy1.dir/all] Error 2
mingw32-make[1]: Leaving directory 'D:/DEV/cpp/projects/udemy1/build'
mingw32-make: *** [Makefile:83: all] Error 2

我确实尝试编译其他版本的glew。-同样的错误。 我使用 Visual Studio IDE 和预编译库复制了项目（并且它有效）。

Answer 1

静态链接到glew时，您需要定义

GLEW_STATIC

预处理器符号：

target_compile_definitions(glew PUBLIC GLEW_STATIC)

如果您不定义此符号，glew 将其所有函数定义为

dllimport

，这就是为什么您会看到

__imp_glewExperimental

缺少符号。