🚀 go-pugleaf

In article <C16K2t.HGC@agora.rain.com>, bobb@agora.rain.com (Bob Beauchemin) writes:
> 
>   I'm having a problem with the NeXT 2.1 compiler and wonder if anyone else
> has experienced it. Code that compiles OK and works on other platforms
> fails on the NeXT. The error messages (at program execution) are:
>
The argument that it runs on other platforms is not so good. Many old style
UNIX programmers messed up int's and pointers freely.....
 
I have had similar problems with free when you give it a pointer that
you did not get from malloc before (like a NULL pointer). It can result
in very erratic behaviour after the (illegal) freeing.
It is just one of those things....
  The standard says what free should do when everything is swell but
of course the question is what it should do when things are wrong. Standards
rarely specify. You could crash the program, continue execution which a
poisoned system (what NeXT does) or when you manage to set up malloc and
free in such a way that nothing gets poisoned just keep running
(like many other systems do).
Unless there is a real programming error inside Mach, I guess formally you
cannot blame NeXT too much. You should have a good look inside your program
and make sure that each pointer that is freed is allowed to be freed.
A little macro like
#define MyFree(x)  if ( x != NULL ) { free(x); x = NULL; }
can work miracles. You could sneak in an else with an error message if you
want to see whether you try to free the same thing twice.
Of course it would be nice if the NeXT would crash the program rather than
continue running.....  Or would it? Maybe a good error message?

Jos Vermaseren