Thread: SDL2 - GCC vs. G++ segmentation fault

For crying out loud, I changes the code, but apparently I didn't... Of course I would like to change it now, but it can't, not can I delete this thread and start a new, nor can I make a duplicate post, a people usually find that annoying...

Anyway, here's the actual code:

Code:

...
SDL_Window* gWindow = NULL;

...

gWindow = SDL_CreateWindow( "SDL Tutorial", 0, 0, 1280, 720, SDL_WINDOW_BORDERLESS );

...

if( gWindow == NULL ) // segmentation fault with gcc and not with g++

I've tried just about everything I can think of, but all my research has achieved is to confirm that there is indeed a difference if you compile with gcc or g++, though usually the roles are reversed, as compared to this case.

Apparently, when running the program through gdb, the segmentation fault doesn't occur. Either that, or I completely misinterpret the out put, which wouldn't be too surprising, but for now I'll assume that things just keep getting weirder and weirder.

Originally Posted by WoodSTokk

I'm missing the init-function for SDL in your code.
Your code should have the following fuctions as a mimimum.

Code:

…
    SDL_Window* gWindow = NULL;

//Initialize SDL
    if( SDL_Init( SDL_INIT_VIDEO ) < 0 )
    {
        printf( "SDL could not initialize! SDL_Error: %s\n", SDL_GetError() );
        return 1;
    }
…
    gWindow = SDL_CreateWindow( "SDL Tutorial", 0, 0, 1280, 720, SDL_WINDOW_BORDERLESS );
…
    if( gWindow == NULL ) // segmentation fault with gcc and not with g++
…
//Destroy window
    SDL_DestroyWindow( gWindow );

//Quit SDL subsystems
    SDL_Quit();
…

I only posted what seems relevant, as I know where the segmentation fault occur. Here it is in it's entirety, which is nothing really but at standard test case you can get from about any tutorial on the subject:

Code:

#include "SDL2/SDL.h"
#include <stdio.h>

//The window we'll be rendering to
SDL_Window* gWindow = NULL;
    
//The surface contained by the window
SDL_Surface* gScreenSurface = NULL;


//The image we will load and show on the screen
SDL_Surface* gHelloWorld = NULL;


const int SCREEN_WIDTH = 1920;
const int SCREEN_HEIGHT = 1080;


int init()
{
    //Initialization flag
    int success = 1;


    //Initialize SDL
    if( SDL_Init( SDL_INIT_VIDEO ) < 0 )
    {
        printf( "SDL could not initialize! SDL_Error: %s\n", SDL_GetError() );
        success = 0;
    }
    else
    {
        //Create window
        gWindow = SDL_CreateWindow( "SDL Tutorial", 0, 0, SCREEN_WIDTH, SCREEN_HEIGHT, SDL_WINDOW_BORDERLESS );
        if( gWindow == NULL )
        {
            printf( "Window could not be created! SDL_Error: %s\n", SDL_GetError() );
            success = 0;
        }
        else
        {
            //Get window surface
            gScreenSurface = SDL_GetWindowSurface( gWindow ); // SEGMENTATION FAULT!
        }
    }
    
    return success;
}


int loadMedia()
{
    //Loading success flag
    int success = 1;


    //Load splash image
    gHelloWorld = SDL_LoadBMP( "img.bmp" );
    if( gHelloWorld == NULL )
    {
        printf( "Unable to load image %s! SDL Error: %s\n", "02_getting_an_image_on_the_screen/hello_world.bmp", SDL_GetError() );
        success = 0;
    }


    return success;
}


void close()
{
    //Deallocate surface
    SDL_FreeSurface( gHelloWorld );
    gHelloWorld = NULL;


    //Destroy window
    SDL_DestroyWindow( gWindow );
    gWindow = NULL;


    //Quit SDL subsystems
    SDL_Quit();
}


int main(int argc, char* args[])
{
    //Start up SDL and create window
    if( !init() )
    {
        printf( "Failed to initialize!\n" );
    }
    else
    {
        //Load media
        if( !loadMedia() )
        {
            printf( "Failed to load media!\n" );
        }
        else
        {
            //Apply the image
            SDL_BlitSurface( gHelloWorld, NULL, gScreenSurface, NULL );
            //Update the surface
            SDL_UpdateWindowSurface( gWindow );
            //Wait two seconds
            SDL_Delay( 2000 );
        }
    }


    //Free resources and close SDL
    close();


    return 0;
}

I really wish I could delete this thread or at least edit it, as, once again, I've confused my self and others by posting the wrong stuff.

Where the segmentation fault occur is at the line:
"gScreenSurface = SDL_GetWindowSurface( gWindow );"
now proven with finality, but as I mentioned earlier, it does not occur when compiling with g++, as opposed to gcc, which is very confusing.

Thank for trying. As I said, running it through gdb apparently does not cause a seg fsult, so it is really weird.

Anyway, if it matters, I'm on a x86_64 arch box with proprietary nvidia driver.

i will of course continue to try and figure it out, but for now i think ill try to get some actual work done.