Re: [Cobolforgcc-devel] Debug Error Routines

[Tim J. <te...@me...>]

Steven,

Look at cobumem.c and cobutil.c in the CVS for examples. I have
pasted one below. Note that asserts do not have to be protected
by the #if, because they do nothing if NDEBUG is set. Thus the
two naked asserts at the end.

If the debugging is on, I do lots of checks for integrity of the
memory allocation, buffer overrunrs etc. Each allocated area has
a magic number for validation, and the length etc. This all
disappears when debug is turned off.

So, for example, you can put 
assert(pointer1!=NULL); 
and such all over the place. You could check that the parameters
passed are consistent. 

The only thing to be careful of is to make sure none of the
operational code is in asserts or within the #ifndef scope. This
would be bad

int next_ix=0;
assert(next_ix++<MAX); << increament won't happen if debug turned
off
item[next_ix]=stuff;

By the way if you register with sourceforge I can record your
work in the task tracking system.

Regards,
Tim Josling

> #ifndef NDEBUG
>   for (mem=first_malloc; mem; mem=mem->next) 
>     {
>       
>       counter++;
>       totaller+=mem->size;
>       
>       assert(mem->size>0);
>       assert(mem->magic==MAGIC1);
>       
>       if (mem==first_malloc) 
>         assert(!(mem->prev));
>       else 
>         {
>           assert (mem->prev);
>           assert (mem->prev->next==mem);
>         }
>       if (mem==last_malloc) 
>         assert(!(mem->next));
>       else 
>         {
>           assert (mem->next);
>           assert (mem->next->prev==mem);
>         }
>       
>       memend=(struct malloc_trailer*)(((char*)mem)+(mem->size)+sizeof(struct malloc_header));
>       assert(memend->magic==MAGIC2);
>       
>     }
>   
> #endif
>   assert(counter==(malloc_count-free_count));
>   assert(totaller==(malloc_total-free_total));