Re: [PATCH] mips-tdep.c: Fix bug in evaluating signed address

[Daniel Jacobowitz <drow@false.org>]

On Fri, Jun 16, 2006 at 06:23:32PM +0200, Corinna Vinschen wrote:
> Hi,
> 
> the below patch fixes the mips_integer_to_address function.  What
> happens is this:
> 
> If the incoming type is an *unsigned* value, then unpack_long takes the
> (un)signedness into account.  This results in `val' not being signed
> extended, as the mips_integer_to_address function was originally
> designed for.
> 
> So, to enforce correct signedness of the resulting address, I changed
> the unpack_long call to extract_signed_integer.  This way, val is always
> sign extended and the mips address is correctly signed.

I might be missing something, but isn't the function mostly redundant
now?

> Index: gdb/mips-tdep.c
> ===================================================================
> RCS file: /cvs/cvsfiles/gnupro/gdb/mips-tdep.c,v
> retrieving revision 1.24
> diff -u -p -r1.24 mips-tdep.c
> --- gdb/mips-tdep.c	15 Jun 2006 08:57:17 -0000	1.24
> +++ gdb/mips-tdep.c	16 Jun 2006 16:15:48 -0000
> @@ -4749,7 +4749,7 @@ mips_integer_to_address (struct gdbarch 
>  			 struct type *type, const gdb_byte *buf)
>  {
>    gdb_byte *tmp = alloca (TYPE_LENGTH (builtin_type_void_data_ptr));
> -  LONGEST val = unpack_long (type, buf);
> +  LONGEST val = extract_signed_integer (buf, TYPE_LENGTH (type));
>    store_signed_integer (tmp, TYPE_LENGTH (builtin_type_void_data_ptr), val);
>    return extract_signed_integer (tmp,
>  				 TYPE_LENGTH (builtin_type_void_data_ptr));

Those last two have got to be a no-op.

-- 
Daniel Jacobowitz
CodeSourcery