Undefined reference errors in Qt application

Question

I have a library and example application, driven by CMake. So, there is a class, which I use in library:

sourceeditor.h

#ifndef SOURCEEDITOR_H
#define SOURCEEDITOR_H

#include <QWidget>
#include "novile_export.h"

namespace Novile
{

class SourceEditorPrivate;
class NOVILE_EXPORT SourceEditor : public QWidget
{
    Q_OBJECT
public:
    explicit SourceEditor(QWidget *parent = 0);
    ~SourceEditor();

private:
    SourceEditorPrivate * const d;

};

} // namespace Novile

#endif // SOURCEEDITOR_H

sourceeditor.cpp

#include <QtCore>
#include <QVBoxLayout>
#include <QWebView>
#include "novile_debug.h"
#include "sourceeditor.h"

namespace Novile
{

class SourceEditorPrivate
{
public:
    SourceEditorPrivate(SourceEditor *p = 0) :
        parent(p),
        aceView(new QWebView(p)),
        layout(new QVBoxLayout(p))
    {
        parent->setLayout(layout);
        layout->addWidget(aceView);
    }

    ~SourceEditorPrivate()
    {
    }

    void loadAceView()
    {
        aceView->load(QUrl("qrc:/ace.html"));
    }

private:
    SourceEditor *parent;
    QWebView *aceView;
    QVBoxLayout *layout;
};

SourceEditor::SourceEditor(QWidget *parent) :
    QWidget(parent),
    d(new SourceEditorPrivate(this))
{
    mDebug() << "Source Editor has been started";

    d->loadAceView();
}

SourceEditor::~SourceEditor()
{
}

} // namespace Novile

and example:

main.cpp

#include <QApplication>
#include "../src/sourceeditor.cpp"

int main(int argc, char *argv[])
{
    QApplication app(argc, argv);

    Novile::SourceEditor editor;
    editor.setGeometry(100, 50, 600, 300);
    editor.show();

    return app.exec();
}

Then I receive a lot of ld errors:

CMakeFiles/example.dir/main.cpp.o: In function `Novile::SourceEditor::SourceEditor(QWidget*)':
../src/sourceeditor.cpp:39: undefined reference to `vtable for Novile::SourceEditor'
../src/sourceeditor.cpp:39: undefined reference to `vtable for Novile::SourceEditor'
CMakeFiles/example.dir/main.cpp.o: In function `Novile::SourceEditor::~SourceEditor()':
../src/sourceeditor.cpp:46: undefined reference to `vtable for Novile::SourceEditor'
../src/sourceeditor.cpp:46: undefined reference to `vtable for Novile::SourceEditor'
collect2: error: ld returned 1 exit status

This file (main.cpp) represents example application, which should test core functionality of library.

You're probably missing a `Q_OBJECT` macro, but since you're not showing the definition of the `SourceEditor` class, hard to tell. — Mat, Mar 29 '13 at 11:15

Andy Prowl · Answer 1 · 2013-03-29T11:45:08.883

1

The problem is most likely due to the fact that you are #includeing a .cpp file:

#include "../src/sourceeditor.cpp"

You shouldn't do that, and you don't need it. Just include the corresponding header sourceeditor.h and, if needed, the novile_debug.h header.

Then, make sure both main.cpp and sourceeditor.cpp are part of your project, so that the compiler will process both these translation units and the linker will eventually merge the corresponding object code into the executable of your program.

edited Mar 29 '13 at 11:45

answered Mar 29 '13 at 11:24

Andy Prowl

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The problem is I don't have hpp file and I need code from .cpp file, too. There are library and example executable (main.cpp) – Ian P Badtrousers Mar 29 '13 at 11:41
@IllyaKovalevskyy: Sorry, I meant `sourceeditor.h`, the header file you have. – Andy Prowl Mar 29 '13 at 11:45
Then I have errors because I haven't included implementation, which is stored in .cpp – Ian P Badtrousers Mar 29 '13 at 11:47
@IllyaKovalevskyy: What implementation? What errors are you getting? You should never `#include` a `.cpp` file – Andy Prowl Mar 29 '13 at 11:50

Undefined reference errors in Qt application

1 Answers1