Allegro error checking system

I am making an Allegro game, and I think it would be good to have a nice error checking system laid out before I start coding, this is how I usualy do it, I don't think it is good enough, what kind of systems do you use with your Allegro programs?

Code:

/*******************/
/* V-Ball          */
/* Undefined Games */
/*******************/

#include <allegro.h>


  FILE   *fp     = NULL;
  BITMAP *buffer = NULL;

  int  setup();
  void shutdown();

int main()
{
  fp = fopen("log.txt", "w");
  if(fp == NULL)
  {
    printf("Could not open log file, exiting...");
    return 0;
  }

  fprintf(fp, "Starting program execution\n");

  if(setup() != 0)
  {
    fprintf(fp, "Setup failed\n");
  }
  else
  {
    while(!key[KEY_ESC])
      ;
  }

  shutdown();
  return 0;
}
END_OF_MAIN();

/*******************/

int setup()
{
  allegro_init();

  if(install_keyboard() != 0)
  {
    fprintf(fp, "Could not install keyboard\n");
    return 1;
  }

  buffer = create_bitmap(640, 480);
  if(buffer == NULL)
  {
    fprintf(fp, "Could not create buffer\n");
    return 1;
  }

  set_color_depth(32);
  if(set_gfx_mode(GFX_AUTODETECT_FULLSCREEN, 640, 480, 0, 0) != 0)
  {
    fprintf(fp, "Could not set graphics mode\n");
    return 1;
  }

  return 0;
}

/*******************/

void shutdown()
{
  destroy_bitmap(buffer);

  fprintf(fp, "Ending program execution\n");
  fclose(fp);
}

/*******************/

That seems good enough to me. In fact I don't go nearly as far as you do. About the only thing different I do is if the color depth can't be set to 32 I try to set it to a lower value.

I was thinking of creating an enumerated constant with different errors, then having a function log_error() that will print more information about it.

Code:

enum errors { UNABLE_SET_GRAPHICS, UNABLE_LOAD_SPRITE, ... };

if(error)
{
  log_error(UNABLE_LOAD_SPRITE);
}

log_error(int e)
{
  switch(e)
  {
    case UNABLE_LOAD_SPRITE:
      fprintf(fp, "Unable to load the sprite, sprite.bmp\n");
      break;
    default:
      break;
  }
}