Re: another emi2 bugfix

On Tuesday 06 August 2002 01:21 pm, Harrie Hazewinkel wrote:
> --On Tuesday, August 6, 2002 1:14 PM +0300 Oded Arbel <[email protected]>
>
> wrote:
> > On Tuesday 06 August 2002 12:38 pm, Harrie Hazewinkel wrote:
> >> The patch below would combine a free(ptr) and a ptr=NULL
> >> into a single gw_free(ptr) statement. The extra vaiable is needed
> >> in case the variable is returned from a function.
> >> This should be wise to include too, I guess.
> >
> > <snip>
> >
> >> +#define gw_free(ptr) {void *p=ptr;gw_native_free(p);p=NULL;}
> >
> > don't you mean :
> ># define gw_free(ptr) {void *p=ptr;gw_native_free(p);ptr=NULL;}
> > as p is freed from the stack anyway at the end of the macro block. the
> > same to  the other change.
>
> NO, since 'ptr' can be directly returned from a function and that
> cannot be made NULL. However, I realise now also that this
> would not do the trick. It makes the new variable NULL, but not the
> pointer I wanted.
>
> Better drop it for now, and add explicits NULL assignments
> each time when needed.

Why would you ever want to return a pointer after calling gw_free on it ? 
after freeing a memory segment, the pointer to it must either be set to NULL 
or discarded.
doing 
gw_free(pointer);
return pointer;
make no sense what so ever, unless gw_free also assigns NULL to the pointer.

-- 
Oded Arbel
m-Wise mobile solutions
[email protected]

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