Problem with disassembler and SIGILL signal

mrjj

So it sounds like where ever it crashes its not in
your code and it shows assem as it have no source ?

Amaury

I don't know it sound like this yes , but it crashes at the starting point of my app, just showing my first window and then crashing.
But when I just run my app it's starting normally and then crashing after a couple of minutes without any explications .
That's why I need to debug, but if the problem is something out of the app I don't know how to deal with it.

mrjj

Hi
Dont you have idea in where in the app it could be ?
Or what action or processing that is going on when crashing.

When it crash, did the call stack showed more info on where it was?
http://doc.qt.io/qtcreator/creator-debug-mode.html
"Viewing Call Stack Trace"

Amaury

Alright after setting a break point as you recommended I was using F10 to check if there's some code that was walling the SIGILL signal , I think I found where my problem is .

That's my main :

int main(int argc, char *argv[])
{
    //QTextCodec::setCodecForCStrings(QTextCodec::codecForName("UTF-8"));
    //QTextCodec::setCodecForTr(QTextCodec::codecForName("UTF-8"));

    QApplication a(argc, argv);

    QTranslator qtTranslator;
       qtTranslator.load(
               "qt_" + QLocale::system().name(),
               QLibraryInfo::location(QLibraryInfo::TranslationsPath)
               );
       a.installTranslator(&qtTranslator);

    MainWindow w;
    w.show();

    MemTampon::Db.aff_Temperature();
    MemTampon::Db.aff_Humidite();
    MemTampon::Db.aff_Puissance();
    MemTampon::Db.aff_Nom_SD();


    return a.exec();

All of this is running nice except when I'm trying to run (with F11 or f10 key ) the return a.exec() which giving the SIGILL signal

Ps : I set the breakpoint first on w.show and then on the line bfore the return function.

mrjj

Hi
I dont like the look of
a.installTranslator(&qtTranslator);
Since you give it address of a local variable.
So if it thinks it owns the translator ( as expects a pointer) then it will be double deleted by
"a" and by running out of scope. (after .exe())

Could you try to new it and see if it still crashes?

update:
Hmm Docs dont say it owns it.

Amaury

I have to say that I found this piece of code and just add it to my program since I had some pop-ups written in english ( I'm french).

So is something like this that you mean by new it ? :

QTranslator *qtTranslator = new QTranslator;
      qtTranslator.load(
              "qt_" + QLocale::system().name(),
              QLibraryInfo::location(QLibraryInfo::TranslationsPath)
              );
      a.installTranslator(&qtTranslator);

   return a.exec();

because I can't even copile like this ...

mrjj

hi
yes
except now its pointer, u must get rid of &
a.installTranslator(qtTranslator);

Amaury

That's compiling but when I'm debugging it's still crashing at the same point ...

kshegunov

SIGILL is very unusual, it often means the binary is corrupt (it's the illegal instruction signal). What compiler are you using?
As for @mrjj's suggestion, you can still create on the stack, but do unregister the translator before returning from main(), e.g.:

int main()
{
    // ...
    QTranslator qtTranslator;
    qtTranslator.load("qt_" + QLocale::system().name(), QLibraryInfo::location(QLibraryInfo::TranslationsPath));
    a.installTranslator(&qtTranslator);

    int retcode = a.exec();
    a.removeTranslator(&qtTranslator);

    return retcode;
}

Amaury

I am using Gdb as debugger and Gcc as a compiler , I forget to precise that I was on a raspberry Pi 3.
I would try your way and come back again.

mrjj

@Amaury
Hi
Ok. it was not the translator it seems.

Do you have global object or anything else that might run out of scope and be deleted twice?
You should try putting break point in mainwindow destructor and see if it gets to that part.

Amaury

I have a .h and .cpp named global Where I put 2 global variables as extern. Maybe it's the problem I'm Setting a point break on the Main window and sending you my global.h and global .cpp

Global.h

#ifndef GLOBAL_H
#define GLOBAL_H

#include <QString>

QT_BEGIN_NAMESPACE
class QString;
QT_END_NAMESPACE

extern QString OnlinePath;
extern int Var;


#endif // GLOBAL_H

Global.cpp

`#include "global.h"
#include <QString>


QString OnlinePath= "http://192.168.1.242/app.php/api/smartdevice";
int Var = 0;


``

kshegunov

Are you sure that this compiler produces binaries for that particular instruction set? Look up the compatibility of your gcc version with the instruction set of that particular Pi.

mrjj

Hmm dont seems like it as just a Qstring.
Its more if you have a widget and assign parent.
Then both scope and parent might delete it and it might crash.

Dont the call stack give hint what it was doing ?

Amaury

@kshegunov Sorry I didn't understand anything I'm not really used with the debuggers.

@mrjj Hum I am associating widgets to a parent when using a QStackWidget for example I got my main window with some widgets in it. It the main ui of my application.

I am adding some widgets in a QStackedWidget on the MainWindow and calling them by using their names .

MainWindow

MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
    ui(new Ui::MainWindow)
{

    //this->setWindowFlags(Qt::FramelessWindowHint);

    ui->setupUi(this);
    this->move(this->x(),this->y());

    AccueilWindow = new Accueil(this,"AccueilWindow");
    ui->stackedWidget->addWidget(AccueilWindow);

ui->stackedWidget->setCurrentWidget(AccueilWindow);

connect(this,SIGNAL(changeInterface(QString)),this,SLOT(changeOnglet(QString)));
}

void MainWindow::changeOnglet(QString name)
{
    qDebug()<<name;
    if ((name == AccueilWindow->objectName())&&AccueilWindow)
    {
        ui->stackedWidget->setCurrentWidget(AccueilWindow);
        hide_full_ui();
        show_ui();
        return;
    }
    else if ((name == AlarmesWindow->objectName())&&AlarmesWindow)
    {
        ui->stackedWidget->setCurrentWidget(AlarmesWindow);
        show_ui();
        return;
    }
}

Mainwindow.h

private:
    
    Ui::MainWindow *ui;

    Accueil *AccueilWindow;
    Alarmes *AlarmesWindow;

The alarm.cpp

Alarmes::Alarmes(QWidget *parent,QString AlarmesWindow) :
    QWidget(parent),
    Alrm_ui(new Ui::Alarmes)
{
    Alrm_ui->setupUi(this);


    this->setObjectName(AlarmesWindow);
    connect(this,SIGNAL(changeInterface(QString)),qobject_cast<MainWindow *>(parent),SLOT(changeOnglet(QString)));
}

alarm.h

namespace Ui {
class Alarmes;
}

class Alarmes : public QWidget
{
    Q_OBJECT

public:
    explicit Alarmes(QWidget *parent ,QString AlarmesWindow);
    virtual ~Alarmes();

mrjj

Hi
Nothing springs to eye. Seems you let the Qt system handle it.

If you create a default Widgets project and run it on the pi.

Does that also crash at close?

Amaury

If i delete the whole Qtranslator thing it seems that's not ceashing anymore , there just a message saying starting the debug and debug ended. I assume that's ok ...

I didn't tried to let some other programm running to see if there's something but I didn't found any problems on an other application .

Edit : It seems that other programs have no problem ..

And I don't have any more troubles if my main.cpp is like :

int main(int argc, char *argv[])
{
    QTextCodec::setCodecForCStrings(QTextCodec::codecForName("UTF-8"));
    QTextCodec::setCodecForTr(QTextCodec::codecForName("UTF-8"));

    QApplication a(argc, argv);

//    QTranslator qtTranslator;
//        qtTranslator.load("qt_" + QLocale::system().name(), QLibraryInfo::location(QLibraryInfo::TranslationsPath));
//        a.installTranslator(&qtTranslator);





    MainWindow w;
    w.show();

    MemTampon::Db.aff_Temperature();
    MemTampon::Db.aff_Humidite();
    MemTampon::Db.aff_Puissance();
    MemTampon::Db.aff_Nom_SD();


//    a.removeTranslator(&qtTranslator);
    return a.exec();
}

mrjj

Ok
Im not sure what to conclude from that :)
But seems to be related to it anyway then.

Amaury

Yes I'm really not sure about it that's really pointing on this but don't know what's wrong ...

I think I'm going to create some buttons that are written in my language instead of using the Qt popup default buttons.

Thanks for help I'm closing this subject and put it as solved .

See you in a close future I think ^^

Edit Seems to be the return a.exec() that is bugged don't know why ^^

mrjj

@Amaury said in Problem with disassembler and SIGILL signal:

Edit Seems to be the return a.exec() that is bugged don't know why ^^

For QApplication it has setting that says When last window closed,
exit the event loop ( exec() ) and die.
see
app.setQuitOnLastWindowClosed(true);
This is in effect sort of the same as
app.connect(&app, SIGNAL(lastWindowClosed()), &app, SLOT(quit()));

So if some sort of instruction that gets called when deconstructing then it will
show exec() as the the point of crash.