Compiling Qt5 App on Raspberry - c++

Question

I'd like to compile a program on my Raspberry Pi 3.
I've installed the latest Raspbian and crosscompiled Qt 5.8 as described in this manual and then I've tried to build GST to run it on the board. The compile process seems to finish, however, I've got following linker errors:
root#raspberrypi:/home/pi/headunit-WIP-headunit-gst/gst# make
g++ -fPIC -std=c++11 `pkg-config --cflags gstreamer-1.0 gstreamer-app-1.0 gstreamer-video-1.0 libcrypto libusb-1.0 openssl` -I../jni -I/opt/Qt5.8/include/QtWidgets -I/opt/Qt5.8/include -I/opt/Qt5.8/include/QtGui -c main.cc -o main.o
g++ -o headunit ../jni/hu_aad.o ../jni/hu_aap.o ../jni/hu_ssl.o ../jni/hu_usb.o ../jni/hu_uti.o main.o `pkg-config --libs gstreamer-1.0 gstreamer-app-1.0 gstreamer-video-1.0 libcrypto libusb-1.0 openssl` -L/opt/Qt5.8/include/QtCore/QtCore -L/opt/Qt5.8/include/QtWidgets/QtWidgets -L/opt/Qt5.8/include/QtGui/QtGui
main.o: In function `gst_loop(gst_app_t*, QApplication*)':
main.cc:(.text+0xb5c): undefined reference to `QApplication::exec()'
main.o: In function `main':
main.cc:(.text+0x10e0): undefined reference to `QApplication::QApplication(int&, char**, int)'
main.cc:(.text+0x10f0): undefined reference to `qFlagLocation(char const*)'
main.cc:(.text+0x1104): undefined reference to `qFlagLocation(char const*)'
main.cc:(.text+0x1134): undefined reference to `QObject::connect(QObject const*, char const*, QObject const*, char const*, Qt::ConnectionType)'
main.cc:(.text+0x1140): undefined reference to `QMetaObject::Connection::~Connection()'
main.cc:(.text+0x1178): undefined reference to `QWidget::show()'
main.cc:(.text+0x11bc): undefined reference to `QWidget::winId() const'
main.cc:(.text+0x1280): undefined reference to `QWidget::hide()'
main.cc:(.text+0x12c4): undefined reference to `QApplication::~QApplication()'
main.cc:(.text+0x12e4): undefined reference to `QApplication::~QApplication()'
main.o: In function `QWidget::resize(int, int)':
main.cc:(.text._ZN7QWidget6resizeEii[_ZN7QWidget6resizeEii]+0x38): undefined reference to `QWidget::resize(QSize const&)'
main.o: In function `HuMainWindow::HuMainWindow()':
main.cc:(.text._ZN12HuMainWindowC2Ev[_ZN12HuMainWindowC5Ev]+0x38): undefined reference to `QMainWindow::QMainWindow(QWidget*, QFlags<Qt::WindowType>)'
main.o: In function `HuMainWindow::~HuMainWindow()':
main.cc:(.text._ZN12HuMainWindowD2Ev[_ZN12HuMainWindowD5Ev]+0x48): undefined reference to `QMainWindow::~QMainWindow()'
main.o:(.data.rel.ro._ZTV12HuMainWindow[_ZTV12HuMainWindow]+0x8): undefined reference to `QMainWindow::metaObject() const'
main.o:(.data.rel.ro._ZTV12HuMainWindow[_ZTV12HuMainWindow]+0xc): undefined reference to `QMainWindow::qt_metacast(char const*)'
main.o:(.data.rel.ro._ZTV12HuMainWindow[_ZTV12HuMainWindow]+0x10): undefined reference to `QMainWindow::qt_metacall(QMetaObject::Call, int, void**)'
main.o:(.data.rel.ro._ZTV12HuMainWindow[_ZTV12HuMainWindow]+0x1c): undefined reference to `QMainWindow::event(QEvent*)'
main.o:(.data.rel.ro._ZTV12HuMainWindow[_ZTV12HuMainWindow]+0x20): undefined reference to `QObject::eventFilter(QObject*, QEvent*)'
main.o:(.data.rel.ro._ZTV12HuMainWindow[_ZTV12HuMainWindow]+0x24): undefined reference to `QObject::timerEvent(QTimerEvent*)'
main.o:(.data.rel.ro._ZTV12HuMainWindow[_ZTV12HuMainWindow]+0x28): undefined reference to `QObject::childEvent(QChildEvent*)'
main.o:(.data.rel.ro._ZTV12HuMainWindow[_ZTV12HuMainWindow]+0x2c): undefined reference to `QObject::customEvent(QEvent*)'
main.o:(.data.rel.ro._ZTV12HuMainWindow[_ZTV12HuMainWindow]+0x30): undefined reference to `QObject::connectNotify(QMetaMethod const&)'
main.o:(.data.rel.ro._ZTV12HuMainWindow[_ZTV12HuMainWindow]+0x34): undefined reference to `QObject::disconnectNotify(QMetaMethod const&)'
main.o:(.data.rel.ro._ZTV12HuMainWindow[_ZTV12HuMainWindow]+0x38): undefined reference to `QWidget::devType() const'
main.o:(.data.rel.ro._ZTV12HuMainWindow[_ZTV12HuMainWindow]+0x3c): undefined reference to `QWidget::setVisible(bool)'
main.o:(.data.rel.ro._ZTV12HuMainWindow[_ZTV12HuMainWindow]+0x40): undefined reference to `QWidget::sizeHint() const'
main.o:(.data.rel.ro._ZTV12HuMainWindow[_ZTV12HuMainWindow]+0x44): undefined reference to `QWidget::minimumSizeHint() const'
main.o:(.data.rel.ro._ZTV12HuMainWindow[_ZTV12HuMainWindow]+0x48): undefined reference to `QWidget::heightForWidth(int) const'
main.o:(.data.rel.ro._ZTV12HuMainWindow[_ZTV12HuMainWindow]+0x4c): undefined reference to `QWidget::hasHeightForWidth() const'
main.o:(.data.rel.ro._ZTV12HuMainWindow[_ZTV12HuMainWindow]+0x50): undefined reference to `QWidget::paintEngine() const'
main.o:(.data.rel.ro._ZTV12HuMainWindow[_ZTV12HuMainWindow]+0x5c): undefined reference to `QWidget::mouseDoubleClickEvent(QMouseEvent*)'
main.o:(.data.rel.ro._ZTV12HuMainWindow[_ZTV12HuMainWindow]+0x64): undefined reference to `QWidget::wheelEvent(QWheelEvent*)'
main.o:(.data.rel.ro._ZTV12HuMainWindow[_ZTV12HuMainWindow]+0x68): undefined reference to `QWidget::keyPressEvent(QKeyEvent*)'
main.o:(.data.rel.ro._ZTV12HuMainWindow[_ZTV12HuMainWindow]+0x6c): undefined reference to `QWidget::keyReleaseEvent(QKeyEvent*)'
main.o:(.data.rel.ro._ZTV12HuMainWindow[_ZTV12HuMainWindow]+0x70): undefined reference to `QWidget::focusInEvent(QFocusEvent*)'
main.o:(.data.rel.ro._ZTV12HuMainWindow[_ZTV12HuMainWindow]+0x74): undefined reference to `QWidget::focusOutEvent(QFocusEvent*)'
main.o:(.data.rel.ro._ZTV12HuMainWindow[_ZTV12HuMainWindow]+0x78): undefined reference to `QWidget::enterEvent(QEvent*)'
main.o:(.data.rel.ro._ZTV12HuMainWindow[_ZTV12HuMainWindow]+0x7c): undefined reference to `QWidget::leaveEvent(QEvent*)'
main.o:(.data.rel.ro._ZTV12HuMainWindow[_ZTV12HuMainWindow]+0x80): undefined reference to `QWidget::paintEvent(QPaintEvent*)'
main.o:(.data.rel.ro._ZTV12HuMainWindow[_ZTV12HuMainWindow]+0x84): undefined reference to `QWidget::moveEvent(QMoveEvent*)'
main.o:(.data.rel.ro._ZTV12HuMainWindow[_ZTV12HuMainWindow]+0x88): undefined reference to `QWidget::resizeEvent(QResizeEvent*)'
main.o:(.data.rel.ro._ZTV12HuMainWindow[_ZTV12HuMainWindow]+0x8c): undefined reference to `QWidget::closeEvent(QCloseEvent*)'
main.o:(.data.rel.ro._ZTV12HuMainWindow[_ZTV12HuMainWindow]+0x90): undefined reference to `QMainWindow::contextMenuEvent(QContextMenuEvent*)'
main.o:(.data.rel.ro._ZTV12HuMainWindow[_ZTV12HuMainWindow]+0x94): undefined reference to `QWidget::tabletEvent(QTabletEvent*)'
main.o:(.data.rel.ro._ZTV12HuMainWindow[_ZTV12HuMainWindow]+0x98): undefined reference to `QWidget::actionEvent(QActionEvent*)'
main.o:(.data.rel.ro._ZTV12HuMainWindow[_ZTV12HuMainWindow]+0x9c): undefined reference to `QWidget::dragEnterEvent(QDragEnterEvent*)'
main.o:(.data.rel.ro._ZTV12HuMainWindow[_ZTV12HuMainWindow]+0xa0): undefined reference to `QWidget::dragMoveEvent(QDragMoveEvent*)'
main.o:(.data.rel.ro._ZTV12HuMainWindow[_ZTV12HuMainWindow]+0xa4): undefined reference to `QWidget::dragLeaveEvent(QDragLeaveEvent*)'
main.o:(.data.rel.ro._ZTV12HuMainWindow[_ZTV12HuMainWindow]+0xa8): undefined reference to `QWidget::dropEvent(QDropEvent*)'
main.o:(.data.rel.ro._ZTV12HuMainWindow[_ZTV12HuMainWindow]+0xac): undefined reference to `QWidget::showEvent(QShowEvent*)'
main.o:(.data.rel.ro._ZTV12HuMainWindow[_ZTV12HuMainWindow]+0xb0): undefined reference to `QWidget::hideEvent(QHideEvent*)'
main.o:(.data.rel.ro._ZTV12HuMainWindow[_ZTV12HuMainWindow]+0xb4): undefined reference to `QWidget::nativeEvent(QByteArray const&, void*, long*)'
main.o:(.data.rel.ro._ZTV12HuMainWindow[_ZTV12HuMainWindow]+0xb8): undefined reference to `QWidget::changeEvent(QEvent*)'
main.o:(.data.rel.ro._ZTV12HuMainWindow[_ZTV12HuMainWindow]+0xbc): undefined reference to `QWidget::metric(QPaintDevice::PaintDeviceMetric) const'
main.o:(.data.rel.ro._ZTV12HuMainWindow[_ZTV12HuMainWindow]+0xc0): undefined reference to `QWidget::initPainter(QPainter*) const'
main.o:(.data.rel.ro._ZTV12HuMainWindow[_ZTV12HuMainWindow]+0xc4): undefined reference to `QWidget::redirected(QPoint*) const'
main.o:(.data.rel.ro._ZTV12HuMainWindow[_ZTV12HuMainWindow]+0xc8): undefined reference to `QWidget::sharedPainter() const'
main.o:(.data.rel.ro._ZTV12HuMainWindow[_ZTV12HuMainWindow]+0xcc): undefined reference to `QWidget::inputMethodEvent(QInputMethodEvent*)'
main.o:(.data.rel.ro._ZTV12HuMainWindow[_ZTV12HuMainWindow]+0xd0): undefined reference to `QWidget::inputMethodQuery(Qt::InputMethodQuery) const'
main.o:(.data.rel.ro._ZTV12HuMainWindow[_ZTV12HuMainWindow]+0xd4): undefined reference to `QWidget::focusNextPrevChild(bool)'
main.o:(.data.rel.ro._ZTV12HuMainWindow[_ZTV12HuMainWindow]+0xd8): undefined reference to `QMainWindow::createPopupMenu()'
main.o:(.data.rel.ro._ZTV12HuMainWindow[_ZTV12HuMainWindow]+0xec): undefined reference to `non-virtual thunk to QWidget::devType() const'
main.o:(.data.rel.ro._ZTV12HuMainWindow[_ZTV12HuMainWindow]+0xf0): undefined reference to `non-virtual thunk to QWidget::paintEngine() const'
main.o:(.data.rel.ro._ZTV12HuMainWindow[_ZTV12HuMainWindow]+0xf4): undefined reference to `non-virtual thunk to QWidget::metric(QPaintDevice::PaintDeviceMetric) const'
main.o:(.data.rel.ro._ZTV12HuMainWindow[_ZTV12HuMainWindow]+0xf8): undefined reference to `non-virtual thunk to QWidget::initPainter(QPainter*) const'
main.o:(.data.rel.ro._ZTV12HuMainWindow[_ZTV12HuMainWindow]+0xfc): undefined reference to `non-virtual thunk to QWidget::redirected(QPoint*) const'
main.o:(.data.rel.ro._ZTV12HuMainWindow[_ZTV12HuMainWindow]+0x100): undefined reference to `non-virtual thunk to QWidget::sharedPainter() const'
main.o:(.data.rel.ro._ZTI12HuMainWindow[_ZTI12HuMainWindow]+0x8): undefined reference to `typeinfo for QMainWindow'
collect2: error: ld returned 1 exit status
Makefile:23: recipe for target 'headunit' failed
make: *** [headunit] Error 1
As far as I understand, there is no reference to QApplication, but I wrote it in the Makefile:
CC=gcc
CPP=g++
LD=ld
INCLUDES=`pkg-config --cflags gstreamer-1.0 gstreamer-app-1.0 gstreamer-video-1.0 libcrypto libusb-1.0 openssl` -I$(TOP)/jni -I/opt/Qt5.8/include/QtWidgets -I/opt/Qt5.8/include -I/opt/Qt5.8/include/QtGui
CFLAGS=
CPPFLAGS=-fPIC -std=c++11
LFLAGS=`pkg-config --libs gstreamer-1.0 gstreamer-app-1.0 gstreamer-video-1.0 libcrypto libusb-1.0 openssl` -L/opt/Qt5.8/include/QtCore/QtCore -L/opt/Qt5.8/include/QtWidgets/QtWidgets -L/opt/Qt5.8/include/QtGui/QtGui
TOP = ..
AASRCS = $(TOP)/jni/hu_aad.c \
$(TOP)/jni/hu_aap.c \
$(TOP)/jni/hu_ssl.c \
$(TOP)/jni/hu_usb.c \
$(TOP)/jni/hu_uti.c
HSRCS = main.cc
OBJS = $(AASRCS:.c=.o) $(HSRCS:.cc=.o)
APP = headunit
.PHONY: depend clean
all: $(APP)
$(APP): $(OBJS)
$(CPP) -o $(APP) $(OBJS) $(LFLAGS)
.c.o:
$(CC) $(CFLAGS) $(INCLUDES) -c $< -o $#
.cc.o:
$(CPP) $(CPPFLAGS) $(INCLUDES) -c $< -o $#
clean:
rm -f $(OBJS) *~ $(APP)
depend: $(SRCS)
makedepend $^
# DO NOT DELETE
I also tried qmake -project to get a project file and then qmake and make.
But then i receive other errors.
Maybe someone can help me fixing these problems to finally compile this program.

Answer 1

did you try to let the Pi find the libraries by adding the /lib folder of the Qt installation to ld.so.conf?
In your case this would maybe look like echo /opt/Qt5.8/lib | sudo tee /etc/ld.so.conf.d/qt5pi.conf
After that you have to reload the ld.so.conf by using sudo ldconfig
Now the linker can find the Qt-Libs without any additions to your Makefile.
Maybe this will help you.