write-only variables in src/sys/ - possible bugs

[Andrew Thompson]

On Mon, Feb 02, 2009 at 08:42:32PM +0100, Christoph Mallon wrote:
> Hi,
> 
> I compiled a list of all local variables in src/sys/ (r188000), which are 
> only written to, but never read. This is more than the GCC warning, which 
> only complains about variables, which are only declared (and maybe 
> initialised) and not used otherwise. In contrast this list contains 
> variables with the following usage pattern:
> 
> int w = 42; // GCC warns about this ...
> int x;      // ... but not this
> x = 23;
> x++;
> return 0;
> 
> The list contains about 700 entries. About three dozen concern variables 
> named 'error'. Here's one *example* from the list:
> 
> 	sys/dev/kbdmux/kbdmux.c:1304
> 
> In the function kbdmux_modevent() the variable 'error' is assigned values 
> eight times, but at the end of the function there is just a return 0; and 
> the variable is never read. Probably the value should be returned.
> 
> You can find the list here:
> 	http://tron.homeunix.org/unread_variables.log
> 
> The list was generated by cparser, a C99 compiler, which uses libFIRM for 
> optimisation and code generation (lang/cparser in the ports).

This is helpful, my only nit would be to run it through sort. :)

Andrew