undefined reference to `main'

[Landslyde]

Following a C++ tutorial, the user (using CodeBlocks) has me to add a class through the File Menu: File -> New -> Class

So now I have main.cpp, bottles.cpp and bottles.h. But, unlike his that works, mine throws an error when I try to run it:

Code Select Expand

-------------- Build: Debug in tut-002 (compiler: GNU GCC Compiler)---------------

g++ -Wall -fexceptions -g -std=c++11 -I -c /home/slyde/Desktop/CB/Tutorials/tut-002/bottles.cpp -o obj/Debug/bottles.o
/usr/lib/gcc/x86_64-linux-gnu/5/../../../x86_64-linux-gnu/crt1.o: In function `_start':
(.text+0x20): undefined reference to `main'
collect2: error: ld returned 1 exit status
Process terminated with status 1 (0 minute(s), 0 second(s))
1 error(s), 0 warning(s) (0 minute(s), 0 second(s))

main.cpp has a main in it.

Code Select Expand

#include <iostream>
#include "bottles.h"

//using namespace std;

int main()
{
    bottles bo;
    return 0;
}

bottles.cpp:

Code Select Expand

#include "bottles.h"
#include <iostream>

bottles::bottles()
{
    std::cout << "Am I a glass bottle? Or am I made of plastic?" << std::endl;
}

bottles.h:

Code Select Expand

#ifndef BOTTLES_H
#define BOTTLES_H


class bottles
{
    public:
        bottles();
    //protected:
    //private:
};

#endif // BOTTLES_H

And the guy in the video...he never references any necessary setting(s) to run this. Will someone tell me what do I have to do to "fix" this? T tried adding a linker option: $(LINK) -nostartfiles -g ... that I got from here. But that didn't work.

Thanks.

[BlueHazzard]

You have to use a project....

[sodev]

... to compile both your cpp-files to link both together to the final application.

[Landslyde]

You have to use a project....

I appreciate you.

**UPDATE**
I wiped out the previous files and started a new Project. I get the same error. And I'm certain this is a Project. View here: https://imgur.com/a/9VpIZ.

Any other ideas?

https://imgur.com/C09EOyg <<== shows it is Project
https://imgur.com/OHSypuy <<== runs deleted code in main

[Landslyde]

I fixed it. But I have no idea how or why it worked out this way.

I closed the Project/Workspace and was prompted that the Project had changed - would I like to save the changes. I did. Then, just out of curiosity, I reopened it. F9 and it compiled and ran as it shld've all along.

Why did it take me closing it for it to save the changes and "fix" itself?

[BlueHazzard]

How did you added the files?

(@devs and only for the devs: this would not have happened if we save the project before building by default because without fixed (saved) project a build is not  possible, like the source files also have to be saved before build...  )

[Landslyde]

1) File -> New -> Project (game me main.cpp
2) File -> New-> Class (game me bottles.h and bottles.cpp)

[BlueHazzard]

And at the popup about selecting target you enabled the tick on both?

[Landslyde]

I did.

[BlueHazzard]

i see from your signature that you are using a 5 year old release of codeblocks. Can you try the latest release? Can you reproduce this problem?

[Landslyde]

Three of the Debian files won't install. Dependencies aren't satisfied. Ever. I wish Mint wld update their damn depository!

[oBFusCATed]

Have you passed all dep packages in a single command? Are you using the correct packages?

[Landslyde]

No. I haven't tried to knock them all out in a single cmd. Here's what I tried to use:

[Landslyde]

Can you reproduce this problem?

Ten times out of ten. I can reproduce this issue with my eyes closed.

[BlueHazzard]

you can also try this ppa https://launchpad.net/~damien-moore/+archive/ubuntu/codeblocks
this are basically nightly builds so will get the latest version. I don't know if your linux mint is there.

Or you compile it by yourself. It is pretty easy. I tried to write a little instruction:
https://github.com/bluehazzard/codeblocks_sf/wiki/build_linux_mint_18

it is not complete but the make install way worked for me and was pretty easy.