* Borislav Petkov [off-list ref] wrote:

Add a 'W=1' Makefile switch which adds additional checking per build
object.

The idea behind this option is targeted at developers who, in the
process of writing their code, want to do the occasional

make W=1 [target.o]

and let gcc do more extensive code checking for them. Then, they
could eyeball the output for valid gcc warnings about various
bugs/discrepancies which are not reported during the normal build
process.

For more background information and a use case, read through this
thread: http://marc.info/?i=20110218091716.GA4384@bicker

Cc: Ingo Molnar <redacted>
Cc: Michal Marek <redacted>
Cc: linux-kbuild@vger.kernel.org
Signed-off-by: Borislav Petkov <bp@alien8.de>

Nice.

Acked-by: Ingo Molnar <redacted>

We enable a lot of GCC warnings in tools/perf/ as well, and while there are false 
positives occasionally, the general effect on code quality is positive. We combine 
it with -Werror to make sure warnings do not accumulate.

Thanks,

	Ingo