CMake add_library: error LNK2001: unresolved external symbol "struct QMetaObject const myClass::staticMetaObject"

tracyma

Get link error when build dll library: 1>animationitem.obj : error LNK2001: unresolved external symbol "struct QMetaObject const myclass::staticMetaObject" (?staticMetaObject@myclass@@3UQMetaObject@@B).

moc_animationitem.cpp is actually generated. I have no idea what's wrong.

VS project is generated from CMake.

Qt 5.12.0
VS 2017 x86

cmake_minimum_required(VERSION 3.10.0)

project(libMyClass)

add_subdirectory( 7zip )

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

find_package(Qt5 COMPONENTS Core Gui Widgets Quick Qml QuickControls2 WebEngineWidgets WebView WebChannel Svg Xml Multimedia REQUIRED)

qt5_add_resources( QT_RESOURCES resource.qrc )

add_library( libMyClass
    SHARED
        # and others ...
        items/animationitem.cpp
)

target_compile_definitions( libMyClass PRIVATE ITEM_MODE_VIEW BUILD_XESLIDE_DLL )
#target_compile_options( libMyClass PRIVATE -Wall )
target_compile_features( libMyClass PRIVATE cxx_std_17 )

target_include_directories( libMyClass
    PRIVATE 
        .
        7zip/win/CPP 
        7zip/win/C
        player/player_widgets
        UI
)

target_link_libraries( libMyClass 
    PUBLIC 
        Qt5::Core 
        Qt5::Gui
        Qt5::Widgets 
        Qt5::Quick 
        Qt5::Qml 
        Qt5::QuickControls2 
        Qt5::WebEngineWidgets 
        Qt5::WebView 
        Qt5::WebChannel 
        Qt5::Svg 
        Qt5::Xml 
        Qt5::Multimedia
        libArchive
        user32.lib
)

SGaist

Hi,

Based on the cmake-qt documentation, it seems you have to include the corresponding generated files at the bottom of your .cpp files.

tracyma

have tried, do not work. : <

AnimationItem is QQuickItem-derived , how to deal with custom item in dll ? should i qmlRegisterType the item somewhere ?

VRonin

qt5_add_resources is obsolete. if you set(CMAKE_AUTORCC ON) just add your .qrc files as they were .cpp to add_library/add_executable
moc needs the headers, make sure CMake can see them, usually you can use set(CMAKE_INCLUDE_CURRENT_DIR ON)