Qt项目CMake构建出现vtable未定义引用问题及解决

问题描述 #

在使用CMake构建基于Qt6的EventCameraAnalysis项目时出现链接错误，相关代码及错误信息如下：

初始CMakeLists.txt #

cmake_minimum_required(VERSION 3.16)
project(EventCameraAnalysis
  LANGUAGES CXX C
  VERSION 0.1.0) 

set(CMAKE_EXPORT_COMPILE_COMMANDS ON)

set(CMAKE_AUTOMOC ON)
set(CMAKE_AUTORCC ON)
set(CMAKE_AUTOUIC ON)

find_package(Qt6 COMPONENTS Widgets Charts REQUIRED)

add_subdirectory(libs/qcustomplot)

add_executable(${PROJECT_NAME} src/EventCameraThread.cpp src/main.cpp)

target_link_libraries(${PROJECT_NAME} PRIVATE Qt6::Widgets Qt6::Charts qcustomplot)

target_include_directories(
  EventCameraAnalysis
  PUBLIC $<BUILD_INTERFACE:${CMAKE_SOURCE_DIR}/include>
         $<BUILD_INTERFACE:${CMAKE_BINARY_DIR}/include>
         $<INSTALL_INTERFACE:include>
  PRIVATE ${CMAKE_CURRENT_SOURCE_DIR})

target_compile_definitions(${PROJECT_NAME} PRIVATE QCUSTOMPLOT_USE_LIBRARY)

EventCameraThread.h #

#pragma once

#include <QObject>
#include <QThread>
#include <QMutex>
#include <QWaitCondition>

#include <metavision/sdk/driver/camera.h>

class EventCameraThread : public QThread
{
    Q_OBJECT

public:
    EventCameraThread(QObject *parent = nullptr);
    ~EventCameraThread();

    void run() override;

signals:
    void newFrame(const QImage &frame);
    void error(int socketError, const QString &message);

private:
    QMutex mutex_;
    QWaitCondition cond_;
    bool quit_;

    Metavision::Camera camera_;
};

EventCameraThread.cpp #

#include <event_camera_analysis/EventCameraThread.h>

EventCameraThread::EventCameraThread(QObject *parent)
: QThread(parent), quit_{false} {}

EventCameraThread::~EventCameraThread() {}


void EventCameraThread::run() {
}

构建错误信息 #

In file included from /usr/include/x86_64-linux-gnu/qt6/QtGui/QtGui:61,
                 from /usr/include/x86_64-linux-gnu/qt6/QtPrintSupport/QtPrintSupportDepends:4,
                 from /usr/include/x86_64-linux-gnu/qt6/QtPrintSupport/QtPrintSupport:3,
                 from /data/repos/phd/event_camera_analysis/libs/qcustomplot/qcustomplot.h:97,
                 from /data/repos/phd/event_camera_analysis/src/main.cpp:19:
/usr/include/x86_64-linux-gnu/qt6/QtGui/qopenglcontext.h:56:2: warning: #warning qopenglfunctions.h is not compatible with GLEW, GLEW defines will be undefined [-Wcpp]
   56 | #warning qopenglfunctions.h is not compatible with GLEW, GLEW defines will be undefined
      |  ^~~~~~~
/usr/include/x86_64-linux-gnu/qt6/QtGui/qopenglcontext.h:57:2: warning: #warning To use GLEW with Qt, do not include <qopengl.h> or <QOpenGLFunctions> after glew.h [-Wcpp]
   57 | #warning To use GLEW with Qt, do not include <qopengl.h> or <QOpenGLFunctions> after glew.h
      |  ^~~~~~~
In file included from /usr/include/x86_64-linux-gnu/qt6/QtGui/qopenglextrafunctions.h:47,
                 from /usr/include/x86_64-linux-gnu/qt6/QtGui/QtGui:62,
                 from /usr/include/x86_64-linux-gnu/qt6/QtPrintSupport/QtPrintSupportDepends:4,
                 from /usr/include/x86_64-linux-gnu/qt6/QtPrintSupport/QtPrintSupport:3,
                 from /data/repos/phd/event_camera_analysis/libs/qcustomplot/qcustomplot.h:97,
                 from /data/repos/phd/event_camera_analysis/src/main.cpp:19:
/usr/include/x86_64-linux-gnu/qt6/QtGui/qopenglfunctions.h:49:2: warning: #warning qopenglfunctions.h is not compatible with GLEW, GLEW defines will be undefined [-Wcpp]
   49 | #warning qopenglfunctions.h is not compatible with GLEW, GLEW defines will be undefined
      |  ^~~~~~~
/usr/include/x86_64-linux-gnu/qt6/QtGui/qopenglfunctions.h:50:2: warning: #warning To use GLEW with Qt, do not include <qopengl.h> or <QOpenGLFunctions> after glew.h [-Wcpp]
   50 | #warning To use GLEW with Qt, do not include <qopengl.h> or <QOpenGLFunctions> after glew.h
      |  ^~~~~~~
[100%] Linking CXX executable EventCameraAnalysis
/usr/bin/ld: CMakeFiles/EventCameraAnalysis.dir/src/EventCameraThread.cpp.o: in function `EventCameraThread::EventCameraThread(QObject*)':
/data/repos/phd/event_camera_analysis/src/EventCameraThread.cpp:4: undefined reference to `vtable for EventCameraThread'
/usr/bin/ld: CMakeFiles/EventCameraAnalysis.dir/src/EventCameraThread.cpp.o: in function `EventCameraThread::~EventCameraThread()':
/data/repos/phd/event_camera_analysis/src/EventCameraThread.cpp:6: undefined reference to `vtable for EventCameraThread'
collect2: error: ld returned 1 exit status
make[2]: *** [CMakeFiles/EventCameraAnalysis.dir/build.make:155: EventCameraAnalysis] Error 1
make[1]: *** [CMakeFiles/Makefile2:103: CMakeFiles/EventCameraAnalysis.dir/all] Error 2
make: *** [Makefile:91: all] Error 2

解决方案 #

使用CMake的qt_wrap_cpp工具处理包含Q_OBJECT宏的头文件，确保MOC（元对象编译器）正确生成元对象代码，修改后的CMakeLists.txt如下：

cmake_minimum_required(VERSION 3.16)
project(EventCameraAnalysis
  LANGUAGES CXX
  VERSION 0.1.0) 

set(CMAKE_EXPORT_COMPILE_COMMANDS ON)

set(CMAKE_AUTOMOC ON)
set(CMAKE_AUTORCC ON)
set(CMAKE_AUTOUIC ON)

find_package(Qt6 COMPONENTS Core Widgets Charts REQUIRED)

find_package(MetavisionSDK COMPONENTS core driver ui REQUIRED)

add_subdirectory(libs/qcustomplot)

qt_wrap_cpp(SOURCES include/event_camera_analysis/EventCameraThread.h
                    include/event_camera_analysis/QtGuiApplication.h)

qt_add_executable(${PROJECT_NAME} src/EventCameraThread.cpp src/QtGuiApplication.cpp ${SOURCES} src/main.cpp)

target_link_libraries(${PROJECT_NAME}
  PRIVATE
  Qt6::Core Qt6::Widgets Qt6::Charts qcustomplot MetavisionSDK::core MetavisionSDK::driver MetavisionSDK::ui)

target_include_directories(
  EventCameraAnalysis
  PUBLIC $<BUILD_INTERFACE:${CMAKE_SOURCE_DIR}/include>
         $<BUILD_INTERFACE:${CMAKE_BINARY_DIR}/include>
         $<INSTALL_INTERFACE:include>
  PRIVATE ${CMAKE_CURRENT_SOURCE_DIR})

target_compile_features(${PROJECT_NAME} PUBLIC cxx_std_17)

target_compile_definitions(${PROJECT_NAME} PRIVATE QCUSTOMPLOT_USE_LIBRARY)

关键修改说明 #

• 新增qt_wrap_cpp命令，显式指定需要MOC处理的头文件，解决包含Q_OBJECT类的虚表未定义问题。
• 添加Qt6::Core组件依赖，确保Qt核心功能完整。
• 引入MetavisionSDK的依赖查找与链接，适配项目中使用的Metavision::Camera类。
• 使用qt_add_executable替代add_executable，符合Qt6的CMake规范。

内容的提问来源于stack exchange，提问作者Andreas Ziegler