Weird undefined error regarding object in a class when it has been defined...

[DexTr]

So, I've read a lot about undefined errors, but I'm confused about my situation, and even a little worried since the error message isn't something "clean".

Here's my code. First, the .h file :

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include <QtSerialPort/QSerialPort>
#include <QSerialPortInfo>
#include <QProgressDialog>
#include <QProgressBar>
#include <QThread>
#include <QFile>
#include <QFileDialog>
#include <QLabel>
#include <QString>
#include <QIODevice>
extern "C"{
#include "bootloader.h"
}



QT_BEGIN_NAMESPACE
namespace Ui { class MainWindow; }
QT_END_NAMESPACE

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    MainWindow(QWidget *parent = nullptr);
    ~MainWindow();

private:
    Ui::MainWindow *ui;
};

class BootLoader
{
    public:
        BootLoader();

        ~BootLoader();
        BOOTLOADERERROR err;
        BOOTLOADER b;
        UnionX addr;
        QString port;
        QSerialPortInfo portinfo;

        static QSerialPort BootSerial;
};
#endif // MAINWINDOW_H

Now for the .cpp :

void boot_rst(unsigned char value)
{
    BootLoader::BootSerial.setRequestToSend(value);
}

unsigned char write_uart(unsigned char data_byte_count, unsigned char* data_to_write)
{
    return BootLoader::BootSerial.write((char*) data_to_write, data_byte_count);
}

unsigned char read_uart(unsigned char data_byte_count, unsigned char* data_read)
{
    return BootLoader::BootSerial.read((char*) data_read, data_byte_count);
}

void wait(unsigned int micros)
{
    QObject().thread()->usleep(micros);
}

BootLoader::BootLoader()
{
    err = INIT_NOT_DONE;
    b.init_done = 0;
    b.boot_ready = 0;
    addr.address_l = 0;
    port = QString("COM3");
    portinfo = QSerialPortInfo(port);
    //BootSerial = new QSerialPort(nullptr);

    BootLoader::BootSerial.QSerialPort::setPort(portinfo);
    BootLoader::BootSerial.setBaudRate(115200);
    BootLoader::BootSerial.setParity(QSerialPort::EvenParity);

    bootloaderInitQt(&b, boot_rst, write_uart, read_uart, wait);
}

I omitted some stuff which isn't relevant to the part I'm looking at. Now for the error :

:-1: erreur : debug/mainwindow.o:mainwindow.cpp:(.rdata$.refptr._ZN10BootLoader10BootSerialE[.refptr._ZN10BootLoader10BootSerialE]+0x0): undefined reference to `BootLoader::BootSerial'

Could someone help point out what I'm doing wrong here ? The objective is to have those functions write_uart, read_uart etc serve as pointers to functions from the QSerialPort module. I have made a previous version of the bootloader (which works, and is in a .c file), so I'm fairly confident it isn't the cause of the problem. Any idea would be helpful.

Edit to add : I'm using the .c bootloader for compilation, which is where the BOOTLOADER and BOOTLOADERERROR types are defined (one is a structure, the other is an enum to point out what the error is during the program.)

Worth noting, I don't have a lot of experience in C++ ^^"

[DexTr]

Finally figured it out ! I was on the right track, but I wasn't doing things "smart". I ended up making an instance of my BootLoader class in my MainWindow, so I could access the members. I had to put the BootLoader members on public, I had no choice here. But the instanciation made calling on the variables so much easier.

In short, I had only done half the work when I wrote my class, I had to actually use it somewhere.

Thanks for the answers ! And I'll be brushing up my C++ for future use.

Here's what the new code looks like, for reference :

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include <QtSerialPort/QSerialPort>
#include <QSerialPortInfo>
#include <QProgressDialog>
#include <QProgressBar>
#include <QThread>
#include <QFile>
#include <QFileDialog>
#include <QLabel>
#include <QString>
#include <QIODevice>
extern "C"{
#include "bootloader.h"
}



QT_BEGIN_NAMESPACE
namespace Ui { class MainWindow; }
QT_END_NAMESPACE

class BootLoader
{
    public:
        BootLoader();

        ~BootLoader();
    //private:
        BOOTLOADERERROR err;
        BOOTLOADER b;
        UnionX addr;
        QString port;
        QSerialPortInfo portinfo;

        QSerialPort BootSerial;
};

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    MainWindow(QWidget *parent = nullptr);
    ~MainWindow();

private:
    Ui::MainWindow *ui;


    QLabel *statusLabel;
    QLabel *sizeLabel;
    QProgressBar *statusProgressBar;
    QLabel *LabelGive;
    QLabel *LabelGet;
    QSerialPort *serial;
    QString port;
    QSerialPortInfo portinfo;

    BootLoader B;
    void boot_rst(unsigned char value);
    unsigned char write_uart(unsigned char data_byte_count, unsigned char* data_to_write);
    unsigned char read_uart(unsigned char data_byte_count, unsigned char* data_read);
    void wait(unsigned int micros);
};


#endif // MAINWINDOW_H

And the .cpp :

void MainWindow::boot_rst(unsigned char value)
{
    B.BootSerial.setRequestToSend(value);
}

unsigned char MainWindow::write_uart(unsigned char data_byte_count, unsigned char* data_to_write)
{
    return B.BootSerial.write((char*) data_to_write, data_byte_count);
}

unsigned char MainWindow::read_uart(unsigned char data_byte_count, unsigned char* data_read)
{
    return B.BootSerial.read((char*) data_read, data_byte_count);
}

void MainWindow::wait(unsigned int micros)
{
    QObject().thread()->usleep(micros);
}

BootLoader::BootLoader()
{
    err = INIT_NOT_DONE;
    b.init_done = 0;
    b.boot_ready = 0;
    addr.address_l = 0x08000000;
    port = QString("COM3");
    portinfo = QSerialPortInfo(port);
    //BootSerial = new QSerialPort(nullptr);

    /*BootLoader::BootSerial.setPort(portinfo);
    BootLoader::BootSerial.setBaudRate(115200);
    BootLoader::BootSerial.setParity(QSerialPort::EvenParity);
    BootLoader::BootSerial.open(QIODeviceBase::ReadWrite);

    bootloaderInitQt(&b, boot_rst, write_uart, read_uart, wait);*/
    this-> BootSerial.setPort(portinfo);
    BootSerial.setBaudRate(115200);
    BootSerial.setParity(QSerialPort::EvenParity);
}

unsigned char value = 0;

MainWindow::~MainWindow()
{
    delete ui;
}

BootLoader::~BootLoader()
{

}

[J.Hilk]

hi, and welcome

first off, please use code tags for your code, those make reading them much easier :D its ``` in the beginning and the end of the code block

secondly:
static QSerialPort BootSerial;

don't make stack allocated QObjects static! its not permitted and my lead to problems

3rdly:
BootLoader::BootSerial.QSerialPort::setPort(portinfo); this os most definitely the wrong way to access the set port function of your serialport instance :D

class BootLoader
{
public:
    BootLoader();

    ~BootLoader();
private:
    BOOTLOADERERROR err;
    BOOTLOADER b;
    UnionX addr;
    QString port;
    QSerialPortInfo portinfo;

   QSerialPort BootSerial;
};

BootLoader::BootLoader()
{
err = INIT_NOT_DONE;
b.init_done = 0;
b.boot_ready = 0;
addr.address_l = 0;
port = QString("COM3");
portinfo = QSerialPortInfo(port);

//old and wrong
//BootLoader::BootSerial.QSerialPort::setPort(portinfo);
//BootLoader::BootSerial.setBaudRate(115200);
//BootLoader::BootSerial.setParity(QSerialPort::EvenParity);

this-> BootSerial.setPort(portinfo); // this can (in this case) be omitted in c++, the so following is also ok:
BootSerial.setBaudRate(115200);
BootSerial.setParty(QSerialPort::EvenParity);

}

Worth noting, I don't have a lot of experience in C++ ^^"

I could tell :P

[DexTr]

Thanks for the code block tip, makes a world of difference !

The reason I put the parameters as public in the BootLoader class is because I have an issue when setting the pointers to the functions I want. So now, this :

void boot_rst(unsigned char value)
{
    BootLoader::BootSerial.setRequestToSend(value);
}

returns the error : "BootSerial is a private member of BootLoader", hence why I thought putting them as public would help.

[DexTr]

Tried a few more things before I realized I didn't remove the static before my BootSerial member. Now I just have "two" errors to solve, the fact that BootSerial is private or protected and can't be accessed, and the fact that it's a non-static member and I'm using it wrong. It's also something that is going to affect the UnionX member (which is a union between a long int and an array of four bytes for storing an address and rearranging the byte order), so now it's just a matter of what am I doing wrong here.

[DexTr]

Finally figured it out ! I was on the right track, but I wasn't doing things "smart". I ended up making an instance of my BootLoader class in my MainWindow, so I could access the members. I had to put the BootLoader members on public, I had no choice here. But the instanciation made calling on the variables so much easier.

In short, I had only done half the work when I wrote my class, I had to actually use it somewhere.

Thanks for the answers ! And I'll be brushing up my C++ for future use.

Here's what the new code looks like, for reference :

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include <QtSerialPort/QSerialPort>
#include <QSerialPortInfo>
#include <QProgressDialog>
#include <QProgressBar>
#include <QThread>
#include <QFile>
#include <QFileDialog>
#include <QLabel>
#include <QString>
#include <QIODevice>
extern "C"{
#include "bootloader.h"
}



QT_BEGIN_NAMESPACE
namespace Ui { class MainWindow; }
QT_END_NAMESPACE

class BootLoader
{
    public:
        BootLoader();

        ~BootLoader();
    //private:
        BOOTLOADERERROR err;
        BOOTLOADER b;
        UnionX addr;
        QString port;
        QSerialPortInfo portinfo;

        QSerialPort BootSerial;
};

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    MainWindow(QWidget *parent = nullptr);
    ~MainWindow();

private:
    Ui::MainWindow *ui;


    QLabel *statusLabel;
    QLabel *sizeLabel;
    QProgressBar *statusProgressBar;
    QLabel *LabelGive;
    QLabel *LabelGet;
    QSerialPort *serial;
    QString port;
    QSerialPortInfo portinfo;

    BootLoader B;
    void boot_rst(unsigned char value);
    unsigned char write_uart(unsigned char data_byte_count, unsigned char* data_to_write);
    unsigned char read_uart(unsigned char data_byte_count, unsigned char* data_read);
    void wait(unsigned int micros);
};


#endif // MAINWINDOW_H

And the .cpp :

void MainWindow::boot_rst(unsigned char value)
{
    B.BootSerial.setRequestToSend(value);
}

unsigned char MainWindow::write_uart(unsigned char data_byte_count, unsigned char* data_to_write)
{
    return B.BootSerial.write((char*) data_to_write, data_byte_count);
}

unsigned char MainWindow::read_uart(unsigned char data_byte_count, unsigned char* data_read)
{
    return B.BootSerial.read((char*) data_read, data_byte_count);
}

void MainWindow::wait(unsigned int micros)
{
    QObject().thread()->usleep(micros);
}

BootLoader::BootLoader()
{
    err = INIT_NOT_DONE;
    b.init_done = 0;
    b.boot_ready = 0;
    addr.address_l = 0x08000000;
    port = QString("COM3");
    portinfo = QSerialPortInfo(port);
    //BootSerial = new QSerialPort(nullptr);

    /*BootLoader::BootSerial.setPort(portinfo);
    BootLoader::BootSerial.setBaudRate(115200);
    BootLoader::BootSerial.setParity(QSerialPort::EvenParity);
    BootLoader::BootSerial.open(QIODeviceBase::ReadWrite);

    bootloaderInitQt(&b, boot_rst, write_uart, read_uart, wait);*/
    this-> BootSerial.setPort(portinfo);
    BootSerial.setBaudRate(115200);
    BootSerial.setParity(QSerialPort::EvenParity);
}

unsigned char value = 0;

MainWindow::~MainWindow()
{
    delete ui;
}

BootLoader::~BootLoader()
{

}

[J.Hilk]

@DexTr somehow you stopped reading after the class definition I gave. The most relevant part was just a little bit further down:

this-> BootSerial.setPort(portinfo); // this can (in this case) be omitted in c++, the so following is also ok:
BootSerial.setBaudRate(115200);
BootSerial.setParty(QSerialPort::EvenParity);

but, you got it working, and thats what matters!

[DexTr]

@J-Hilk I did read that part and implemented it, but the issues were still there. It was more of a "I was using the class like my left foot" problem.

I got new errors but none warranting a continuation of that thread. Still, thank you for your time and patience !