Hi, I seem to be getting myself into a lot of segmentation fault errors lately. The that currently has me stuck is one that shows up after I exit my program (an SDL App). When I need to debug I usually use the debugger or a Logger class I found and then modified, but none of them work here. The Logger doesn't work because it writes files to a folder, but since the program doesn't close cleanly the file doesn't get written. My debugger doesn't do a traceback and I don't know why. I get the segmentation fault error, the windows close, but the debugger just hangs there with no windows open. Any help finding the Segmentation fault or some reason as to why a segmentation fault would get called after everything closes would be appreciated.

erm..... none of us are clairvoyants...

Would you like to share your code?

Edited 6 Years Ago by Fbody: n/a

I included my code in this post, but the forum is more for general help in finding segmentation faults. You may help me solve this problem, but if I get another I want to be better armed for dealing with it. Thank you for your quick reply.
Since you offered to take a look at my code, I'll give a quick rundown. I'm trying to make a game to help students learn how to synthesize organic compounds. I'm in the very early stages of developments and I'm just trying to get a hold on how a button and gamestates work. Most of this code is modified from Lazy Foo and Tim Jones tutorials. Like i said, I get the segmentation fault only when I try to close the window and the debugger doesn't do a traceback.
Any help regarding my segmentation fault error, my coding style (which I know is severely lacking) or general SDL tips are appreciated. Thank you

Wow, what did I get into?!?

//from CApp.h
        bool OnInit();

        void OnEvent(SDL_Event* Event);

            void OnExit();

        void OnLoop();

        void OnRender();

        void OnCleanup();

Where are these implemented? I can't find them, I looked in CApp.cpp because that made the most sense, they weren't there. I suspect the issue may be in your OnExit() . I'd suggest starting there. If you're using dynamic allocation, you may be overrunning the limits of an array when de-allocating.

Edited 6 Years Ago by Fbody: n/a

Haha, I know my code is big and too spread out, that's kind of why I didn't include it in my first post. The functions you talk about are implemented in CApp::OnExecute. I also think it must have something to do with OnCleanup, but I don't know which. I'm not sure if I'm not freeing the button, the state or the whole App. I would normally use the debugger to see, but it just hangs there indefinitely. I think the problems might be that when I call SDL_QUIT there's still a loaded Image on memory. The problem is that I free all the images in all of my classes's OnCleanup function. It could be that the main loop rund for a while longer and initializes something, but as far as I've checked with the debugger that doesn't happen. By the way, I don't use arrays so that can't be the problem, you don't have to take an in-depth look at my code, some more general advice is also appreciated.

Something that looks suspicious ...

TitleState::~TitleState()
{
    isCurrentState=false;
    StartButton.OnCleanup();
    SDL_FreeSurface(background);
}
//------------------------------------------------------------------------------
void TitleState::OnExit()
{
     StartButton.OnCleanup();
     isCurrentState=false;
     SDL_FreeSurface(background);
}

I'd say that be sure that you don't free anything twice i.e. don't do SDL_FreeSurface(background) , if the 'background' has already been freed.

Then change

void Out(char* words)
{
     printf(words);
}

to

void Out(char* words)
{
     printf("%s", words);
}

Remember that printf() treats its first argument as a format string. And if that string happens to 'resemble' a format string, printf() expects one or more arguments (which are not present), so you'd likely be heading for a nasty surprise.

O.k., followed the suggestions but I'm still getting the fault. I think that I used to be able to compile the program if I edited out the part in OnEvent.cpp that caused the Titlestate to get control of the events. Maybe there's something wrong there? Any other ideas or general advice?

O.k. I switched IDE, CodeBlocks outputs texts to the console instead of to a file so I should be able to get a better idea of where the problem lies. Just in case, I included a traceback that the console windows shows when I close my program. They only thing I can make of it is that there's something from when I free a surface. If you someone can make something more of it or if they come up with more suggestions please let me know. Thanks in advance.

Attachments Screenshot.png 26.99 KB

I owe an apology to mitrmkar, the problem had something to do with what he mentioned in his post. It turns out that Code::Block's debugger outputs to the console so I could directly see where the program crashed. The problem was that I the deconstructor of the Button class was freeing an image that had already been freed. Thank you all for your help.

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