Hi. I have a program with two .cpp files and one .hpp header file. Both the main.cpp and Log.cpp file give different errors on compiling using g++

Question

1. main.cpp

#include <iostream>
#include "log.hpp"

int main()
{
    InitLog();
    Log("Hello World");
    std::cin.get();
}

2. Log.cpp

#include <iostream>
#include "log.hpp"

void InitLog()
{
    Log("Initialize Log");
}

void Log(const char *message)
{
    std::cout << message << std::endl;
}

3. log.hpp

#pragma once

void Log(const char *message);
void InitLog();

The errors are:

1. Log.cpp - undefined reference to `WinMain' collect2.exe: error: ld returned 1 exit status

2. main.cpp - c:/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/12.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:\Users\91813\AppData\Local\Temp\cckelbDG.o:main.cpp:(.text+0xe): undefined reference to InitLog()' c:/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/12.1.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:\Users\91813\AppData\Local\Temp\cckelbDG.o:main.cpp:(.text+0x1d): undefined reference to Log(char const*)' collect2.exe: error: ld returned 1 exit status