3 replies to this topic

[Art n Peace]

I'm using an old book that teaches programming and I keep getting an error that I don't understand. The book is:

Beginning C++ Game Programming by Michael Dawson

I've tried running the code in Dev-C++ and Netbeans IDE. No luck. I'm wondering if the lesson code within is dated (the book is old, 2004)? Here's the program I'm trying to run:

#include <iostream>
using namespace std;
/*
*
*/
int main()
{
	cout << "Game Over!" << endl;
	return 0;
}

Here's the error I'm getting:

build/Debug/Cygwin-Windows/main.o: In function `main':
/cygdrive/c/Users/User2/Documents/NetBeansProjects/cppLessons/main.cpp:15: multiple definition of `_main'
build/Debug/Cygwin-Windows/gameover2.o:/cygdrive/c/Users/User2/Documents/NetBeansProjects/cppLessons/gameover2.cpp:16: first defined here
collect2: ld returned 1 exit status
make[2]: *** [dist/Debug/Cygwin-Windows/cpplessons.exe] Error 1
make[1]: *** [.build-conf] Error 2
make: *** [.build-impl] Error 2

BUILD FAILED (exit value 2, total time: 3s)

What does this mean and how do I fix it? Thank you for your help.

[CarbonAtom]

I tried running it in Code::Blocks and it worked fine.
The code looks fine to me.

[Art n Peace]

I think I figured it out, though I still don't understand what exactly happened.

There was a file which the IDE made by default called main.cpp. Based on the reading of the error which referenced that file, it was somehow being included in the compile process of the gameover.cpp. I don't know why. I deleted the main.cpp and the code ran perfectly.

It would be nice to understand what that error means though. Thanks.

[mrjones]

This error means that you have defined more than one function called main in your code. When your IDE generated the main.cpp, it automatically generated a second main function that you yourself didn't write. Since both main.cpp and gameover2.cpp contained main function, the compiler couldn't decide which is the correct one and generated this error.