在 QtCreator 中使用 oscpack 时出现未定义引用错误
undefined reference errors when using oscpack in QtCreator
我看过几个类似的帖子，但一直无法解决我的具体问题。
我想使用 oscpack，这里有描述，
http://www.rossbencina.com/code/oscpack
并在此处下载，https://github.com/hecomi/qml-osc
然后点击按钮 'clone or download'，然后点击 'Download ZIP' link.
注意：link 我之前的“https://storage.googleapis.com/google-code-archive-downloads/v2/code.google.com/oscpack/oscpack_1_1_0.zip”不正确。
注2：我还在我的Ubuntu18.04系统上安装了oscpack：
$ sudo apt-get -y install liboscpack-dev liboscpack1
在我的项目中包含这个库之后 - 当我添加头文件时 - 我收到多个 undefined reference 错误；例如：
undefined reference to `UdpSocket::Connect(IpEndpointName const&)'
无论我是否使用，我都会得到错误：
LIBS += -L"/developer/3rdPartyLibs/osc/lib" -loscpack # from the downloaded ZIP file
或
LIBS += -L"/usr/lib/x86_64-linux-gnu" -loscpack # from the linux package
在我的 SampleProject.pro 文件中。
我在这里看到了一个非常相似的post/problem：
Linking a static library to my project on Visual Studio 2010
而且我相信我有同样的错误，并且解决方案是相似的（只是我在 Ubuntu 18.04 而不是 Windows 上开发）。我只是还没有想出如何给 linker 它需要的东西。我预计 linker 找不到与 'sys/sockets.h' 关联的库，但我也不知道在哪里可以找到它。我正在使用 Qt Creator 4.10.2，Qt_5_13_2_GCC_64bit-Debug。
如果您不熟悉 QtCreator 但知道需要将哪些命令行参数传递给 ld (and/or g++)，那仍然是一个很大的帮助 - 我可以试着弄清楚在哪里将其添加到 IDE.
我怀疑这个问题不需要额外的信息，但为了以防万一，代码如下。
谢谢！
最小项目（main.qml）：
import QtQuick 2.13
import QtQuick.Controls 2.5
import QtQml 2.13
import OSC 1.0
ApplicationWindow {
visible: true
width: 640
height: 480
title: qsTr("Scroll")
Rectangle {
width: 360
height: 360
Text {
id: message
anchors.centerIn: parent
}
OSCReceiver {
port: 3333
onMessage: {
message.text = address + ' : ' + msg;
}
}
OSCSender {
id: osc
ip: '127.0.0.1'
port: 3333
}
Timer {
property int cnt: 0
interval: 1000/60
running: true
repeat: true
onTriggered: {
osc.send('/Hoge/cnt', ++cnt);
}
}
}
}
项目文件（SampleProject.pro）：
QT += quick
CONFIG += c++11
# The following define makes your compiler emit warnings if you use
# any Qt feature that has been marked deprecated (the exact warnings
# depend on your compiler). Refer to the documentation for the
# deprecated API to know how to port your code away from it.
DEFINES += QT_DEPRECATED_WARNINGS
SOURCES += \
main.cpp
RESOURCES += qml.qrc
LIBS += -L"/developer/3rdPartyLibs/osc/lib" -loscpack # add for oscpack
INCLUDEPATH += /developer/3rdPartyLibs/osc # add for oscpack
include(/developer/3rdPartyLibs/osc/osc.pri) # add for oscpack
# Additional import path used to resolve QML modules in Qt Creator's code model
QML_IMPORT_PATH =
# Additional import path used to resolve QML modules just for Qt Quick Designer
QML_DESIGNER_IMPORT_PATH =
# Default rules for deployment.
qnx: target.path = /tmp/$${TARGET}/bin
else: unix:!android: target.path = /opt/$${TARGET}/bin
!isEmpty(target.path): INSTALLS += target
和main.cpp文件：
#include <QGuiApplication>
#include <QQmlApplicationEngine>
#include <osc_receiver.h> // add for oscpack
#include <osc_sender.h> // add for oscpack
int main(int argc, char *argv[])
{
QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
QGuiApplication app(argc, argv);
qmlRegisterType<OSCReceiver>("OSC", 1, 0, "OSCReceiver"); // add for oscpack
qmlRegisterType<OSCSender>("OSC", 1, 0, "OSCSender"); // add for oscpack
QQmlApplicationEngine engine;
const QUrl url(QStringLiteral("qrc:/main.qml"));
QObject::connect(&engine, &QQmlApplicationEngine::objectCreated,
&app, [url](QObject *obj, const QUrl &objUrl) {
if (!obj && url == objUrl)
QCoreApplication::exit(-1);
}, Qt::QueuedConnection);
engine.load(url);
return app.exec();
}
这是输出：
14:27:49: Running steps for project SampleProject...
14:27:49: Configuration unchanged, skipping qmake step.
14:27:50: Starting: "/usr/bin/make" -j8
g++ -Wl,-rpath,/opt/Qt/5.13.2/gcc_64/lib -o SampleProject main.o osc_sender.o osc_receiver.o qrc_qml.o moc_osc_sender.o moc_osc_receiver.o -L/developer/3rdPartyLibs/osc/lib -loscpack /opt/Qt/5.13.2/gcc_64/lib/libQt5Quick.so /opt/Qt/5.13.2/gcc_64/lib/libQt5Gui.so /opt/Qt/5.13.2/gcc_64/lib/libQt5Qml.so /opt/Qt/5.13.2/gcc_64/lib/libQt5Network.so /opt/Qt/5.13.2/gcc_64/lib/libQt5Core.so -lGL -lpthread -loscpack
osc_sender.o: In function OSCSender::setIp(QString const&)':
/developer/builds/qt/build-SampleProject-Desktop_Qt_5_13_2_GCC_64bit-Debug/../../../3rdPartyLibs/osc/osc_sender.cpp:21: undefined reference toUdpSocket::Connect(IpEndpointName const&)'
osc_sender.o: In function OSCSender::setPort(int)':
/developer/builds/qt/build-SampleProject-Desktop_Qt_5_13_2_GCC_64bit-Debug/Makefile:255: recipe for target 'SampleProject' failed
../../../3rdPartyLibs/osc/osc_sender.cpp:38: undefined reference toUdpSocket::Connect(IpEndpointName const&)'
osc_sender.o: In function OSCSender::send(QString const&, QString const&)':
/developer/builds/qt/build-SampleProject-Desktop_Qt_5_13_2_GCC_64bit-Debug/../../../3rdPartyLibs/osc/osc_sender.cpp:55
...
...many similar lines...
...
undefined reference toSocketReceiveMultiplexer::~SocketReceiveMultiplexer()'
/developer/builds/qt/build-SampleProject-Desktop_Qt_5_13_2_GCC_64bit-Debug/../../../3rdPartyLibs/osc/include/ip/UdpSocket.h:166: undefined reference to UdpSocket::~UdpSocket()'
osc_receiver.o: In functionUdpListeningReceiveSocket::Run()':
/developer/builds/qt/build-SampleProject-Desktop_Qt_5_13_2_GCC_64bit-Debug/../../../3rdPartyLibs/osc/include/ip/UdpSocket.h:169: undefined reference to SocketReceiveMultiplexer::Run()'
osc_receiver.o:(.data.rel.ro._ZTI25UdpListeningReceiveSocket[_ZTI25UdpListeningReceiveSocket]+0x10): undefined reference totypeinfo for UdpSocket'
collect2: error: ld returned 1 exit status
make: *** [SampleProject] Error 1
14:27:51: The process "/usr/bin/make" exited with code 2.
说明
问题在于对库在 C++ 中的 link 编辑方式的误解。集成 oscpack 的 qml-osc 项目使用静态 link（因此没有必要动态 link 它）但不幸的是 liboscpack.a 已经很老了，会产生您观察到的问题。
解决方案
考虑到以上，我已经fork of qml-osc消除了对静态库的依赖，所以必须使用动态link。
考虑到上述情况，您必须遵循以下步骤：
- 安装 liboscpack-dev
sudo apt-get install liboscpack-dev
- 清理您的项目，使其具有以下结构（您可以从 here 下载文件）：
├── 59331063.pro
├── main.cpp
├── main.qml
└── qml.qrc
其中.pro如下：
QT += quick
CONFIG += c++11
DEFINES += QT_DEPRECATED_WARNINGS
SOURCES += main.cpp
RESOURCES += qml.qrc
INCLUDEPATH += /usr/include/oscpack
LIBS += -loscpack
include($$PWD/3rdPartyLibs/qml-osc/osc.pri)
- 然后创建一个名为 3rdPartyLibs 的文件夹并克隆我的存储库：
mkdir 3rdPartyLibs && cd 3rdPartyLibs && git clone https://github.com/eyllanesc/qml-osc.git
最终项目必须具有以下结构：
├── 3rdPartyLibs
│ └── qml-osc
│ ├── LICENSE
│ ├── osc.pri
│ ├── osc_receiver.cpp
│ ├── osc_receiver.h
│ ├── osc_sender.cpp
│ ├── osc_sender.h
│ └── README.md
├── 59331063.pro
├── main.cpp
├── main.qml
└── qml.qrc
目前我无法访问带有 ubuntu 的机器，因此为了测试我之前的程序，我使用了以下 Dockerfile
FROM ubuntu:18.04
MAINTAINER eyllanesc <e.yllanescucho@gmail.com>
RUN apt-get update && \
apt-get autoclean
RUN apt-get update && apt-get install \
-y --no-install-recommends \
git \
ca-certificates \
build-essential \
qt5-default \
qtdeclarative5-dev \
qml-module-qtquick-controls \
qml-module-qtquick-controls2 \
qml-module-qtquick-window2 \
liboscpack-dev
COPY app app
RUN mkdir app/3rdPartyLibs && \
cd app/3rdPartyLibs && \
git clone https://github.com/eyllanesc/qml-osc.git
RUN mkdir app/build && \
cd app/build && \
qmake .. && \
make
CMD app/build/59331063
我看过几个类似的帖子，但一直无法解决我的具体问题。
我想使用 oscpack，这里有描述， http://www.rossbencina.com/code/oscpack
并在此处下载，https://github.com/hecomi/qml-osc 然后点击按钮 'clone or download'，然后点击 'Download ZIP' link.
注意：link 我之前的“https://storage.googleapis.com/google-code-archive-downloads/v2/code.google.com/oscpack/oscpack_1_1_0.zip”不正确。
注2：我还在我的Ubuntu18.04系统上安装了oscpack：
$ sudo apt-get -y install liboscpack-dev liboscpack1
在我的项目中包含这个库之后 - 当我添加头文件时 - 我收到多个 undefined reference 错误；例如：
undefined reference to `UdpSocket::Connect(IpEndpointName const&)'
无论我是否使用，我都会得到错误：
LIBS += -L"/developer/3rdPartyLibs/osc/lib" -loscpack # from the downloaded ZIP file
或
LIBS += -L"/usr/lib/x86_64-linux-gnu" -loscpack # from the linux package
在我的 SampleProject.pro 文件中。
我在这里看到了一个非常相似的post/problem： Linking a static library to my project on Visual Studio 2010
而且我相信我有同样的错误，并且解决方案是相似的（只是我在 Ubuntu 18.04 而不是 Windows 上开发）。我只是还没有想出如何给 linker 它需要的东西。我预计 linker 找不到与 'sys/sockets.h' 关联的库，但我也不知道在哪里可以找到它。我正在使用 Qt Creator 4.10.2，Qt_5_13_2_GCC_64bit-Debug。
如果您不熟悉 QtCreator 但知道需要将哪些命令行参数传递给 ld (and/or g++)，那仍然是一个很大的帮助 - 我可以试着弄清楚在哪里将其添加到 IDE.
我怀疑这个问题不需要额外的信息，但为了以防万一，代码如下。
谢谢！
最小项目（main.qml）：
import QtQuick 2.13
import QtQuick.Controls 2.5
import QtQml 2.13
import OSC 1.0
ApplicationWindow {
visible: true
width: 640
height: 480
title: qsTr("Scroll")
Rectangle {
width: 360
height: 360
Text {
id: message
anchors.centerIn: parent
}
OSCReceiver {
port: 3333
onMessage: {
message.text = address + ' : ' + msg;
}
}
OSCSender {
id: osc
ip: '127.0.0.1'
port: 3333
}
Timer {
property int cnt: 0
interval: 1000/60
running: true
repeat: true
onTriggered: {
osc.send('/Hoge/cnt', ++cnt);
}
}
}
}
项目文件（SampleProject.pro）：
QT += quick
CONFIG += c++11
# The following define makes your compiler emit warnings if you use
# any Qt feature that has been marked deprecated (the exact warnings
# depend on your compiler). Refer to the documentation for the
# deprecated API to know how to port your code away from it.
DEFINES += QT_DEPRECATED_WARNINGS
SOURCES += \
main.cpp
RESOURCES += qml.qrc
LIBS += -L"/developer/3rdPartyLibs/osc/lib" -loscpack # add for oscpack
INCLUDEPATH += /developer/3rdPartyLibs/osc # add for oscpack
include(/developer/3rdPartyLibs/osc/osc.pri) # add for oscpack
# Additional import path used to resolve QML modules in Qt Creator's code model
QML_IMPORT_PATH =
# Additional import path used to resolve QML modules just for Qt Quick Designer
QML_DESIGNER_IMPORT_PATH =
# Default rules for deployment.
qnx: target.path = /tmp/$${TARGET}/bin
else: unix:!android: target.path = /opt/$${TARGET}/bin
!isEmpty(target.path): INSTALLS += target
和main.cpp文件：
#include <QGuiApplication>
#include <QQmlApplicationEngine>
#include <osc_receiver.h> // add for oscpack
#include <osc_sender.h> // add for oscpack
int main(int argc, char *argv[])
{
QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
QGuiApplication app(argc, argv);
qmlRegisterType<OSCReceiver>("OSC", 1, 0, "OSCReceiver"); // add for oscpack
qmlRegisterType<OSCSender>("OSC", 1, 0, "OSCSender"); // add for oscpack
QQmlApplicationEngine engine;
const QUrl url(QStringLiteral("qrc:/main.qml"));
QObject::connect(&engine, &QQmlApplicationEngine::objectCreated,
&app, [url](QObject *obj, const QUrl &objUrl) {
if (!obj && url == objUrl)
QCoreApplication::exit(-1);
}, Qt::QueuedConnection);
engine.load(url);
return app.exec();
}
这是输出：
14:27:49: Running steps for project SampleProject... 14:27:49: Configuration unchanged, skipping qmake step. 14:27:50: Starting: "/usr/bin/make" -j8 g++ -Wl,-rpath,/opt/Qt/5.13.2/gcc_64/lib -o SampleProject main.o osc_sender.o osc_receiver.o qrc_qml.o moc_osc_sender.o moc_osc_receiver.o -L/developer/3rdPartyLibs/osc/lib -loscpack /opt/Qt/5.13.2/gcc_64/lib/libQt5Quick.so /opt/Qt/5.13.2/gcc_64/lib/libQt5Gui.so /opt/Qt/5.13.2/gcc_64/lib/libQt5Qml.so /opt/Qt/5.13.2/gcc_64/lib/libQt5Network.so /opt/Qt/5.13.2/gcc_64/lib/libQt5Core.so -lGL -lpthread -loscpack osc_sender.o: In function
OSCSender::setIp(QString const&)': /developer/builds/qt/build-SampleProject-Desktop_Qt_5_13_2_GCC_64bit-Debug/../../../3rdPartyLibs/osc/osc_sender.cpp:21: undefined reference toUdpSocket::Connect(IpEndpointName const&)' osc_sender.o: In functionOSCSender::setPort(int)': /developer/builds/qt/build-SampleProject-Desktop_Qt_5_13_2_GCC_64bit-Debug/Makefile:255: recipe for target 'SampleProject' failed ../../../3rdPartyLibs/osc/osc_sender.cpp:38: undefined reference toUdpSocket::Connect(IpEndpointName const&)' osc_sender.o: In functionOSCSender::send(QString const&, QString const&)': /developer/builds/qt/build-SampleProject-Desktop_Qt_5_13_2_GCC_64bit-Debug/../../../3rdPartyLibs/osc/osc_sender.cpp:55 ... ...many similar lines... ... undefined reference toSocketReceiveMultiplexer::~SocketReceiveMultiplexer()' /developer/builds/qt/build-SampleProject-Desktop_Qt_5_13_2_GCC_64bit-Debug/../../../3rdPartyLibs/osc/include/ip/UdpSocket.h:166: undefined reference toUdpSocket::~UdpSocket()' osc_receiver.o: In functionUdpListeningReceiveSocket::Run()': /developer/builds/qt/build-SampleProject-Desktop_Qt_5_13_2_GCC_64bit-Debug/../../../3rdPartyLibs/osc/include/ip/UdpSocket.h:169: undefined reference toSocketReceiveMultiplexer::Run()' osc_receiver.o:(.data.rel.ro._ZTI25UdpListeningReceiveSocket[_ZTI25UdpListeningReceiveSocket]+0x10): undefined reference totypeinfo for UdpSocket' collect2: error: ld returned 1 exit status make: *** [SampleProject] Error 1 14:27:51: The process "/usr/bin/make" exited with code 2.
说明
问题在于对库在 C++ 中的 link 编辑方式的误解。集成 oscpack 的 qml-osc 项目使用静态 link（因此没有必要动态 link 它）但不幸的是 liboscpack.a 已经很老了，会产生您观察到的问题。
解决方案
考虑到以上，我已经fork of qml-osc消除了对静态库的依赖，所以必须使用动态link。
考虑到上述情况，您必须遵循以下步骤：
- 安装 liboscpack-dev
sudo apt-get install liboscpack-dev
- 清理您的项目，使其具有以下结构（您可以从 here 下载文件）：
├── 59331063.pro
├── main.cpp
├── main.qml
└── qml.qrc
其中.pro如下：
QT += quick
CONFIG += c++11
DEFINES += QT_DEPRECATED_WARNINGS
SOURCES += main.cpp
RESOURCES += qml.qrc
INCLUDEPATH += /usr/include/oscpack
LIBS += -loscpack
include($$PWD/3rdPartyLibs/qml-osc/osc.pri)
- 然后创建一个名为 3rdPartyLibs 的文件夹并克隆我的存储库：
mkdir 3rdPartyLibs && cd 3rdPartyLibs && git clone https://github.com/eyllanesc/qml-osc.git
最终项目必须具有以下结构：
├── 3rdPartyLibs
│ └── qml-osc
│ ├── LICENSE
│ ├── osc.pri
│ ├── osc_receiver.cpp
│ ├── osc_receiver.h
│ ├── osc_sender.cpp
│ ├── osc_sender.h
│ └── README.md
├── 59331063.pro
├── main.cpp
├── main.qml
└── qml.qrc
目前我无法访问带有 ubuntu 的机器，因此为了测试我之前的程序，我使用了以下 Dockerfile
FROM ubuntu:18.04
MAINTAINER eyllanesc <e.yllanescucho@gmail.com>
RUN apt-get update && \
apt-get autoclean
RUN apt-get update && apt-get install \
-y --no-install-recommends \
git \
ca-certificates \
build-essential \
qt5-default \
qtdeclarative5-dev \
qml-module-qtquick-controls \
qml-module-qtquick-controls2 \
qml-module-qtquick-window2 \
liboscpack-dev
COPY app app
RUN mkdir app/3rdPartyLibs && \
cd app/3rdPartyLibs && \
git clone https://github.com/eyllanesc/qml-osc.git
RUN mkdir app/build && \
cd app/build && \
qmake .. && \
make
CMD app/build/59331063