Problem when compiling in C++ using a mingw and cmake.

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C++

MinGW

cmake

ARM

Hi everyone. My question is same title. Yes problem when compile. Please help me.
This is a code of my program (in CPP):

// Written by UKI COMPUTERS (ukicomputers.github.io - github.com/ukicomputers)
// Based on (C) UKI COMPUTERS Self-Protecting Author License 1.0 (https://github.com/ukicomputers/UKI-COMPUTERS-Self-Protecting-Authors-License)

#include <stdio.h>
#include "pico/stdlib.h"
#include "hardware/gpio.h"
#include "lcd_i2c_quotes/lcd_i2c.h"
#include "hardware/timer.h"
#include "keypad/pico_keypad4x4.h"
#include <cstddef>
using namespace std;

LCDI2C lcd(0x27 , 2, 16, 16, 17, 0);

#define sifra 7 

int pos = 0;    

char Data[sifra]; 
char Master[sifra] = "123456"; // ovo je sifra - u navodnicima. podrazumevana sifra je 123456. i mora imati 6 cifre.

int data_count = 0, master_count = 0;

bool Pass_is_good;
char customKey;

uint columns[4] = { 18, 19, 20, 21 };
uint rows[4] = { 10, 11, 12, 13 };
char matrix[16] = {
    '1', '2' , '3', 'A',
    '4', '5' , '6', 'B',
    '7', '8' , '9', 'C',
    '*', '0' , '#', 'D'
};
bool vrata = true;

#define bravica 16

int bravica_value = 0;

int main()
{
  
  stdio_init_all();
  gpio_init(bravica);
  gpio_set_dir(bravica, GPIO_OUT);

  bravica_value = 0 - bravica_value;
  gpio_put(bravica, bravica_value);
 
  lcd.init();
  lcd.lcd_clear();
  lcd.lcd_string("UKI COMPUTERS");
  lcd.lcd_set_cursor(0, 1);
  lcd.lcd_string("--Wait--");
  sleep_ms(3000);
  lcd.lcd_clear();
  return 0;

}

void Open()
{
  lcd.lcd_set_cursor(0, 0);
  lcd.lcd_string(" Enter Password");
  
  customKey = pico_keypad_get_key();
  if (customKey)
  {
    Data[data_count] = customKey;
    lcd.lcd_set_cursor(data_count, 1);
    lcd.lcd_string(Data);
    data_count++;
  }
}

void clearData()
{
  while (data_count != 0)
  { 
    Data[data_count--] = 0; 
  }
  return;
}

int loop()
{
  if (vrata== 0)
  {
    pico_keypad_init(columns, rows, matrix);
    char customKey;

    customKey = pico_keypad_get_key();

    if (customKey == '#')

    {
      lcd.lcd_clear();
      bravica_value = 1 - bravica_value;
      gpio_put(bravica, bravica_value);
      lcd.lcd_string("  Door is close");
      sleep_ms(3000);
      vrata= 1;
    }

    while(1){
      tight_loop_contents();
    }
  }
  else Open();

  if (data_count == sifra - 1)
  {
    if (!strcmp(Data, Master))
    {
      lcd.lcd_clear();
      bravica_value = 0 - bravica_value;
      gpio_put(bravica, bravica_value);
      lcd.lcd_string("  Door is Open");
      vrata= 0;
    }
    else
    {
      lcd.lcd_clear();
      lcd.lcd_string("  Wrong Password");
      sleep_ms(1000);
      vrata= 1;
    }
    clearData();
  }
}

I'am used a library from GitHub. This is link:
https://github.com/OSWA00/pico-keypad4x4

And i'am for lcd libary used from pico-examples i2c/lcd_i2c_quotes.

When i'am compile a code this error shows to me (after all):

c:/progra~2/gnuarm~1/102021~1.07/bin/../lib/gcc/arm-none-eabi/10.3.1/../../../../arm-none-eabi/bin/ld.exe: CMakeFiles/keypad.dir/C_/Compilers/pico/pico-sdk-master/src/rp2_common/pico_standard_link/crt0.S.obj: in function `__get_current_exception':
(.reset+0x9c): undefined reference to `main'
collect2.exe: error: ld returned 1 exit status
mingw32-make[2]: *** [blink\keypad\CMakeFiles\keypad.dir\build.make:823: blink/keypad/keypad.elf] Error 1
mingw32-make[1]: *** [CMakeFiles\Makefile2:1466: blink/keypad/CMakeFiles/keypad.dir/all] Error 2
mingw32-make: *** [Makefile:90: all] Error 2

How to reslove this error? Please help me.

What I have tried:

I'am tried all things. I'am same don't know what to do. Again please help me and thanks advance.