Re: [Valgrind-users] improbably "uninitialized value" warning

[Daniel M. \(IMI\) <da...@im...>]

----- Original Message ----- 
From: "Bryan O'Sullivan" <bo...@se...>
To: "Daniel Miller (IMI)" <da...@im...>
Cc: "Robert Walsh" <rj...@du...>;
<val...@li...>
Sent: Tuesday, September 28, 2004 11:49
Subject: Re: [Valgrind-users] improbably "uninitialized value" warning


> On Tue, 2004-09-28 at 10:46 -0700, Daniel Miller (IMI) wrote:
> > Okay, I added
> > char xbuf = 0 ;
> > to the beginning of get_number_of_luns().  I understand now that
valgrind
> > doesn't realize that xbuf will be initialized unless usb_control_msg()
> > returned negative value, and in either case get_number_of_luns() will
return
> > a valid value.  So I'll have to add unnecessary initialization code to
quiet
> > valgrind, tho it isn't needed by the actual application.
>
> Why do you think get_number_of_luns is returning a valid value in xbuf?
> It is quite possible that it is not.  Since I assuming you're using
> libusb, you should check the source and find out.
>
> > Are there some kind of conditional compile flags that I can use to
remove
> > such code when I'm not going to run valgrind (similar to the #ifdef
_lint
> > for lint), so I don't always have this extra code installed?
>
> Yes, you can use #ifdef NVALGRIND.  However, if you're talking about
> setting a char value to zero, there's no reason to avoid it.
>
Agreed... I'm thinking more of some other functions which have larger
buffers which I'm having to zero in order to clear valgrind warnings.  OTOH,
since these buffers are all in libusb, I suppose I don't have any guarantee
that there aren't bugs in the code... so I probably *shouldn't* comment out
the inits...