Switch -Wunused-variable on?

[Jan Kratochvil]

On Sun, 22 Apr 2012 09:14:44 +0200, Sergio Durigan Junior wrote:
> However, before continuing to prepare this patch, I would like what you
> think about enabling -Wunused-variable by default in the building.

There are more useful -Wunused* options, GDB uses now:
	-Wno-unused -Wunused-value -Wunused-function

IIRC the counterargument for -Wunused-variable was that GDB contains various
#if-compiled code where is a nightmare to get the code right with matching
#if-clauses also for the variables being used by various #if-compiled code
chunks.  I could not find that mail now in the time I gave to it.

I believe more -Wunused* would be worth it, maybe the mail was before Joel
started to disable -Werror for releases so that claim about problematic
#if-clauses is no longer valid.


Thanks,
Jan