Re: Configure mangles hex values

[Marcelo Tosatti <marcelo.tosatti@cyclades.com>]

Hi Nick,

Curiosity: What was the reason for stripping the leading 0x? 

On Mon, Jan 24, 2005 at 02:41:56PM -0800, Nick Pollitt wrote:
> Sorry about previous message.
> 
> The hex function in scripts/Configure strips the leading 0x from hex values.  
> The 0x needs to be there in autoconf.h, and stripping it out causes the 
> following problematic scenario:
> 
> If I start with a hex value in my config file like this:
> CONFIG_LOWMEM_SIZE=0x40000000
> and then run make oldconfig, it strips out the '0x' so I end up with this:
> CONFIG_LOWMEM_SIZE=40000000
> Then if I run make xconfig, it doesn't think this is a valid hex value, so it
> replaces my value with the default:
> CONFIG_LOWMEM_SIZE=0x20000000
> 
> The following patch removes the lines that strip out 0x, and inserts the 0x if 
> appropriate.
> 
> --- scripts/Configure.orig 2005-01-24 13:31:55.000000000 -0800
> +++ scripts/Configure 2005-01-24 13:34:20.000000000 -0800
> @@ -378,15 +378,18 @@
>  function hex () {
>   old=$(eval echo "\${$2}")
>   def=${old:-$3}
> - def=${def#*[x,X]}
>   while :; do
>     readln "$1 ($2) [$def] " "$def" "$old"
> -   ans=${ans#*[x,X]}
> -   if expr "$ans" : '[0-9a-fA-F][0-9a-fA-F]*$' > /dev/null; then
> -     define_hex "$2" "0x$ans"
> +   if expr "$ans" : '0x[0-9a-fA-F][0-9a-fA-F]*$' > /dev/null; then
> +     define_hex "$2" "$ans"
>       break
>     else
> -     help "$2"
> +     if expr "$ans" : '[0-9a-fA-F][0-9a-fA-F]*$' > /dev/null; then
> +       define_hex "$2" "0x$ans"
> +       break
> +     else
> +       help "$2"
> +     fi
>     fi
>   done
>  }