FreeTDS Development Group

["Craig A. Berry" <craigberry AT mac.com>]

On Mar 23, 2009, at 6:09 AM, Frediano Ziglio wrote:

> 2009/3/21 James K. Lowden <jklowden AT freetds.org>:
> > Craig A. Berry wrote:
> > > > >       if (!(server)) { dbperror(dbproc, 20176, 0, "dbopen",  
> > > > > (int) 2);
> > > > > return (void *)0; };
> > > > >
> > > > > The check isn't against "random data from the stack"; it's against
> > > > > the
> > > > > server argument.
> > > >
> > > > I really wasn't clear (and hadn't looked at the macro long enough  
> > > > to
> > > > understand it).  It's dbproc, not server, that has been "fetched  
> > > > but
> > > > not initialized".
> I think that a
>
> DBPROCESS *dbproc = NULL;
>
> is better... so we check parameter and in case server is NULL we call
> dbperror with proper DBPROCESS (which is NULL).
> I don't understand why gcc don't detect this...


Good question.  The docs here:

<http://gcc.gnu.org/onlinedocs/gcc-4.3.3/gcc/Warning-Options.html#Warning-Options 
>

say that -Wall implies -Wuninitialized only when -01 is in effect, and  
furthermore that -Wuninitialized only works when -O is present because  
without optimization the compiler doesn't have the necessary  
information to detect uninitialized values.  Not sure if that's the  
reason for FreeTDS.

________________________________________
Craig A. Berry
mailto:craigberry AT mac.com

"... getting out of a sonnet is much more
 difficult than getting in."
                 Brad Leithauser