undefined reference to `vtable for shutdown'

[J.Hilk]

@SPlatten selected it in the file explorer of your choice, and press delete on your keyboard

[SPlatten]

@J-Hilk , thank you, how do I identify its where abouts?

[J.Hilk]

@SPlatten if you're using QtCreator, in the project settings tab, its usually parallel to your source folder

[SPlatten]

@J-Hilk , unfortunately not, the build process is entirely using cmake. I've just renamed the build folder and then started off the build again with a new build folder, all the object files were in subfolders of the build folder.

[J.Hilk]

@SPlatten said in undefined reference to `vtable for shutdown':

@J-Hilk , unfortunately not, the build process is entirely using cmake.

qmake or cmake make no difference here, build directory is what you're looking for

[SPlatten]

@J-Hilk , build just completed in new folder with exactly the same results.

[J.Hilk]

@SPlatten ok, one point less to check, very unusual

ok, try adding virtual to your destructor declaration.

did you post the whole class?
are there any other functions, virtual or not, in there?

[SPlatten]

@J-Hilk . that was the entire class, I've added virtual to the destructor prototype, rebuilding now.

[SPlatten]

@J-Hilk, Exactly the same results.

[J.Hilk]

@SPlatten did you make changes in your CMakeLists.txt ?

I assume you have
set(CMAKE_AUTOUIC ON)
set(CMAKE_AUTOMOC ON)
set(CMAKE_AUTORCC ON)
set (CMAKE_INCLUDE_CURRENT_DIR ON)

in it ?

and
set(PROJECT_SOURCES ....)contains your new class ?
as well as
qt5_wrap_cpp qt4_wrap_cpp() (I think that was needed for older version ?)

[SPlatten]

@J-Hilk , I've added the set calls from your post to the make file, the qt4 bits that I did have:

find_package(Qt4 REQUIRED)
include(${QT_USE_FILE})
foreach(loop_var ${QT_LIBRARIES})
  string(REPLACE lib64 lib32 loop_var ${loop_var})
  set(QT_LIBRARIES_32 ${QT_LIBRARIES_32} ${loop_var})
endforeach(loop_var)
qt4_wrap_ui(UI_HEADERS ${FORMS})
qt4_wrap_cpp(MOC_SRCS ${HEADERS})

[SPlatten]

@J-Hilk , Unfortunately, still the same result.

[J.Hilk]

@SPlatten Well,

I'm sorry to say it, but I'm out of ideas. My experience with cmake is very limited and does not reach further :(

[SPlatten]

@J-Hilk , thanks for your time and efforts.

[JoeCFD]

@SPlatten in your source dir where cmake file is located do the following:
mkdir build
cd build
cmake .. -Dyour settings
make -j4

Try to build your code in the build folder all the time. In case you have your vtable issues, simply rm -rf * to delete everything in build dir and redo cmake. Do this only in build dir. Be very careful with rm -rf *. You have to have svn or git for your sources.

[SPlatten]

@JoeCFD , thank you, will give this a go now, I've been doing the following:

Delete build folder
Create build folder
From build folder cmake ${myvariable}
From build folder make

I will try using -j4 on the make.

[JonB]

@SPlatten
Well make -j4 isn't going to fix anything :)

Your code looks right to me (especially the Q_OBJECT, whose absence/change can often cause this). Given that you say you have cleaned everything out and rebuilt I am not sure what is wrong (unless there is some artefact left around somewhere it is still seeing).

From the linker messages undefined reference to vtable for 'shutdown' I am unsure whether it is talking about your class shutdown : public QMainWindow { or the Qt-Designer-generated namespace Ui { class shutdown; } (Ui::shutdown). You might just check what is in the generated ui_shutdown.h file to see if it looks good.... (and if that has not been being regenerated, delete it or update the .ui file to make it regenerate, just in case).

[SPlatten]

@JoeCFD , same result.

[SPlatten]

@JonB , thank you, here is ui_shutdown.h:

#ifndef UI_SHUTDOWN_H
#define UI_SHUTDOWN_H

#include <QtCore/QVariant>
#include <QtGui/QAction>
#include <QtGui/QApplication>
#include <QtGui/QButtonGroup>
#include <QtGui/QHeaderView>
#inlcude <QtGui/QLabel>
#include <QtGui/QMainWindow>
#include <QtGui/QWidget>

QT_BEGIN_NAMESPACE

class Ui_shutdown
{
public:
    QWidget *centralWidget;
    QLabel *plblText;

    void setupUi(QMainWindow *shutdown)
    {
        if ( shutdown->objectName().isEmpty())
            shutdown->setObjectName(QString::fromUtf8("shutdown"));
        shutdown->resize(171, 73);
        shutdown->setStyleSheet(QString::fromUtf8("background-color: #0790ff;\n"
"color:#ffffff;\n"
""));
        centralWidget = new QWidget(shutdown);
        centralWidget->setObjectName(QString::fromUtf8("centralWidget"));
        plblText = new QLabel(centralWidget);
        plblText->setObjectName(QString::fromUtf8("plblText"));
        plblText->setGeometry(QRect(0, 0, 171, 71));
        plblText->setStyleSheet(QString::fromUtf8("vertical-align:middle;\n"
"text-align: center;\n"
"font-weight: bold;\n"
""));
        plblText->setAlignment(Qt::AlignCenter);
        shutdown->setCentralWidget(centralWidget);

        retranslateUi(shutdown);

        QMetaObject::connectSlotsByName(shutdown);
    } // setupUi

    void retranslateUi(QMainWindow *shutdown)
    {
        shutdown->setWindowTitle(QString());
        plblText->setText(QApplication::translate("shutdown", "Shutting down...", 0, QApplication::UnicodeUTF8));
    }  // retranslateUi
};

namespace Ui {
    class shutdown: public Ui_shutdown {};
} // namespace Ui

QT_END_NAMESPACE

#endif // UI_SHUTDOWN_H

[JonB]

@SPlatten said in undefined reference to `vtable for shutdown':

../../(shutdown.cc.o): In function `shutdown::shutdown(char const*, QWidget*)':

Note that this .o file is being found in ../.. from where you are/the compiler is being run. Is that indeed correct for you, and where you have deleting files from? Do you by any chance have any other shutdown.cc.o file lying around anywhere from, say, the whole of ../.. downward?

I have no experience of " I have added a class one of the libraries which are built with cmake". But when you do a complete rebuild I am expecting you to see among the commands:

• A uic run on on shutdown.ui, producing ui_shutdown.h.
• A cc (or whatever) compilation run on shutdown.cc, producing shutdown.o.
• A cc on moc_shotdown.cc, or similar, producing <can't recall>.
• Some kind of ld (or maybe cc) doing the linking. It will involve shutdown.cc.o, I can't remember how moc works, whether there is a moc_shutdown.cc.o or just the moc_shutdown.h or whatever source file.

This is not for you to paste the whole output here, it's for you to look at just to verify. It ought be correct anyway.