Re: Compiler warning about comparing result of !!test_bit() to an integer

[David Howells]

Jiri Kosina <jkosina@xxxxxxx> wrote:

> gcc-5 became somehow very picky about '!!' usages. I recall quite some 
> internal discussions with our gcc guys, which resulted in upstream gcc 
> bugzillas being filled about gcc warning in completely legitimate cases.

I suspect it's more that it's picky about '!' usages - which covers '!!'.  I'm
guessing they're trying to pick up people doing if(!x==y) when they mean
if(!(x==y)) or somesuch.
Jiri Kosina <jkosina@xxxxxxx> wrote:

> This is because we want to handle autorepeat (i.e. value 2) correctly. Now 
> that you ask, it seems to me that we actually should be doing
> 
> 	!!test_bit(usage->code, input->key) != !!value

I wonder if you could cast to bool instead?  test_bit() possibly *should*
return a bool these days, thus rendering the '!!' unnecessary.

> to be really exact (i.e. so that we really can't have oscilating state).
> 
> I'll think about it a little bit more, and eventually probably fix it this 
> way with your Reported-by: if you are OK with that.

Yep.

David
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