Re: [libiberty and gdb] floatformat_is_valid

[Daniel Jacobowitz <drow at mvista dot com>]

On Mon, Sep 15, 2003 at 10:39:33AM -0400, Daniel Jacobowitz wrote:
> GDB's "struct value" has a union in it.  This union, named "aligner", has a
> long double member as well as several others; its goal is to be a cheap way
> to ensure that we can load all sorts of values straight from the value
> structure, without alignment problems.  Unfortunately, this means that when
> debugging GDB we tend to feed random bytes to printf ("%.35Lg").  That's not
> kosher, and on i386 I've found a whole bunch of numbers which can crash it -
> the gist is that GMP shifts normalized numbers over until it hits a one bit,
> and if the explicit integer bit isn't set it walks right out of the number.
> 
> This could show up in other places too.  Anywhere you print floating-point
> data from the inferior, really.
> 
> So here's a patch which checks for the problem.  I added
> floatformat_is_valid to libiberty/floatformat.c.  Is this OK?
> [Do I need approval?  Floatformat.c is in libiberty, but marked as part of
> GDB.]
> 
> Oh, this patch misses some copyright year updates.  I'll get them before
> checking in.

Checked in.

-- 
Daniel Jacobowitz
MontaVista Software                         Debian GNU/Linux Developer