Undefined reference to QWidget::styleChange and others

bozo6919

Hi every one,

I'm blocked in a project with theses errors:

/usr/bin/ld: moc_Window.o:(.data.rel.ro._ZTV6Window[_ZTV6Window]+0x188): undefined reference to `QWidget::styleChange(QStyle&)'
/usr/bin/ld: moc_Window.o:(.data.rel.ro._ZTV6Window[_ZTV6Window]+0x190): undefined reference to `QWidget::enabledChange(bool)'
/usr/bin/ld: moc_Window.o:(.data.rel.ro._ZTV6Window[_ZTV6Window]+0x198): undefined reference to `QWidget::paletteChange(QPalette const&)'
/usr/bin/ld: moc_Window.o:(.data.rel.ro._ZTV6Window[_ZTV6Window]+0x1a0): undefined reference to `QWidget::fontChange(QFont const&)'
/usr/bin/ld: moc_Window.o:(.data.rel.ro._ZTV6Window[_ZTV6Window]+0x1a8): undefined reference to `QWidget::windowActivationChange(bool)'
/usr/bin/ld: moc_Window.o:(.data.rel.ro._ZTV6Window[_ZTV6Window]+0x1b0): undefined reference to `QWidget::languageChange()'
collect2: error: ld returned 1 exit status

I have already research on internet why I have theses errors but I've found nothing execepted clean, qmake and re-build, but It doesn't work... :(

Window.hpp:

#include <Qt/qgraphicsview.h>
#include <Qt/qgraphicsscene.h>

class Window : public QGraphicsView
{
	Q_OBJECT

public:
	Window(QGraphicsScene *);
    ~Window();
};

Window.cpp:

#include "Window.hpp"

Window::Window(QGraphicsScene *scene)
	: QGraphicsView(scene)
{
	setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
	setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
	setFocusPolicy(Qt::NoFocus);
	setStyleSheet("QGraphicsView {background: 'black';}");
	resize(640, 640);
	show();
}

Window::~Window()
{
}

int main()
{
	return 0;
}

project.pro:

DEFINES += QT_DEPRECATED_WARNINGS
QT += widgets gui core

INCLUDEPATH += ./include
INCLUDEPATH += ../../core/include

HEADERS += include/Window.hpp
SOURCES += source/Window.cpp

Thanks in advance.

jsulm

@bozo6919 What Qt version do you use and how did you install it?

bozo6919

@jsulm I use Qt 5.11.
I have install it normally ^^ I have already use this version for many other projects.

jsulm

@bozo6919 "normally" can be using Qt Online or Offline installer or your distribution packages.
Are you sure you're using Qt5? Because in Qt5.12 (and I guess Qt5.11) there is no paletteChange for example. But there is such thing in Qt3!
https://doc.qt.io/archives/3.3/qwidget.html#paletteChange

bozo6919

@jsulm Yes I'm sure

And I have only Qt 5.11 and Qt 5.12 installed in my computer. I have already seen in another forum that theses functions are from Qt 3, but I don't know why.

jsulm

@bozo6919 Can you post the compiler output?

bozo6919

@jsulm

clean:

14:01:38: Running steps for project qt...
14:01:38: Starting: "/usr/bin/make" clean -j4
rm -f moc_predefs.h
rm -f Window.o
rm -f *~ core *.core
14:01:38: The process "/usr/bin/make" exited normally.
14:01:38: Elapsed time: 00:00.

qmake:

14:02:18: Running steps for project qt...
14:02:18: Starting: "/home/leo7418/Qt/5.12.0/gcc_64/bin/qmake" /home/leo7418/OOP_arcade_2018/lib/qt/qt.pro -spec linux-g++ CONFIG+=debug CONFIG+=qml_debug
14:02:18: The process "/home/leo7418/Qt/5.12.0/gcc_64/bin/qmake" exited normally.
14:02:18: Starting: "/usr/bin/make" -f /home/leo7418/OOP_arcade_2018/lib/build-qt-Desktop_Qt_5_12_0_GCC_64bit-Debug/Makefile qmake_all
make: Nothing to be done for 'qmake_all'.
14:02:18: The process "/usr/bin/make" exited normally.
14:02:18: Elapsed time: 00:00.

compile:

14:02:50: Running steps for project qt...
14:02:50: Configuration unchanged, skipping qmake step.
14:02:50: Starting: "/usr/bin/make" -j4
g++ -c -pipe -g -Wall -W -D_REENTRANT -fPIC -DQT_DEPRECATED_WARNINGS -DQT_QML_DEBUG -DQT_WIDGETS_LIB -DQT_GUI_LIB -DQT_CORE_LIB -I../qt -I. -I../qt/include -I../../core/include -I../../../Qt/5.12.0/gcc_64/include -I../../../Qt/5.12.0/gcc_64/include/QtWidgets -I../../../Qt/5.12.0/gcc_64/include/QtGui -I../../../Qt/5.12.0/gcc_64/include/QtCore -I. -isystem /usr/include/libdrm -I../../../Qt/5.12.0/gcc_64/mkspecs/linux-g++ -o Window.o ../qt/source/Window.cpp
g++ -Wl,-rpath,/home/leo7418/Qt/5.12.0/gcc_64/lib -o qt Window.o   -L/home/leo7418/Qt/5.12.0/gcc_64/lib -lQt5Widgets -lQt5Gui -lQt5Core -lGL -lpthread   
/usr/bin/ld: /usr/lib/gcc/x86_64-redhat-linux/8/../../../../lib64/crt1.o: in function `_start':
(.text+0x24): undefined reference to `main'
/usr/bin/ld: Window.o:(.data.rel.ro._ZTV6Window[_ZTV6Window]+0x188): undefined reference to `QWidget::styleChange(QStyle&)'
/usr/bin/ld: Window.o:(.data.rel.ro._ZTV6Window[_ZTV6Window]+0x190): undefined reference to `QWidget::enabledChange(bool)'
/usr/bin/ld: Window.o:(.data.rel.ro._ZTV6Window[_ZTV6Window]+0x198): undefined reference to `QWidget::paletteChange(QPalette const&)'
/usr/bin/ld: Window.o:(.data.rel.ro._ZTV6Window[_ZTV6Window]+0x1a0): undefined reference to `QWidget::fontChange(QFont const&)'
/usr/bin/ld: Window.o:(.data.rel.ro._ZTV6Window[_ZTV6Window]+0x1a8): undefined reference to `QWidget::windowActivationChange(bool)'
/usr/bin/ld: Window.o:(.data.rel.ro._ZTV6Window[_ZTV6Window]+0x1b0): undefined reference to `QWidget::languageChange()'
collect2: error: ld returned 1 exit status
make: *** [Makefile:257: qt] Error 1
14:02:51: The process "/usr/bin/make" exited with code 2.
Error while building/deploying project qt (kit: Desktop Qt 5.12.0 GCC 64bit)
When executing step "Make"
14:02:51: Elapsed time: 00:01.

jsulm

@bozo6919 said in Undefined reference to QWidget::styleChange and others:

/usr/bin/ld: /usr/lib/gcc/x86_64-redhat-linux/8/../../../../lib64/crt1.o: in function _start': (.text+0x24): undefined reference to main'

You should fix this issue first: move your main() function in its own file

bozo6919

@jsulm Sorry, I have forgot to put the main (At first my project is a library). But with the main, is the same

SGaist

Hi,

Are you trying to build an old project ?

bozo6919

@SGaist Hi, no I’ve create this project this monday.
I think my Qt version is broken because when I try to compile my project in my second computer, this work :/

SGaist

It looks like it. Since it's the moc related code that has issue, I would check what version is run when you try to build your project.